The present invention relates to an image capture
element, and, more particularly, relates to an image
capture element which detects a phase difference and
captures images and an imaging device.
10
BACKGROUND ART
[0002]
In recent years, imaging devices such as digital
still cameras which capture images of subjects such as
15 people, generate captured images and record these
generated captured images have been spreading. Further,
as such imaging devices, imaging devices which have autofocus
(AF) functions of automatically adjusting focus
(focal point) upon image capturing to facilitate users'
20 image capturing operations are widely spreading.
[0003]
As such imaging devices, imaging devices which form
a pair of images by pupil-dividing light having passed an
image capture lens, and measure an interval between the
25 formed images (detect a phase difference) to determine a
position of the image capture lens (see, for example,
Patent Document 1). This imaging device forms a pair of
images by providing in an image sensor adjusted focus
detection pixels which perform pupil division by blocking
30 half of subject light received by a light reception
element, and calculate an amount of misalignment of focus
by measuring an interval between the formed images.
Further, this imaging device adjusts focus by calculating
the amount of movement of the image capture lens based on
the calculated amount of misalignment of focus, and
5 adjusting the position of the image capture lens based on
the calculated amount of movement (focus adjustment).
CITATION LIST
PATENT DOCUMENT
10 [0004]
Patent Document 1: Japanese Patent Application Laid-Open
No. 2009-145401 (Fig. 15)
SUMMARY OF THE INVENTION
15 PROBLEMS TO BE SOLVED BY THE INVENTION
[0005]
According to the above conventional technique, both
pixels of phase difference detection (adjusted focus
detection pixels (phase difference detection pixels) and
20 captured image generation pixels (image generation
pixels) are provided in one image sensor, and therefore
it is not necessary to provide two sensors of the
adjusted focus detection sensor and the captured image
sensor separately.
25 [0006]
However, according to the above conventional
technique, the phase difference detection pixels cannot
generate a signal and therefore it is necessary to
predict (supplement) data at a position of a phase
30 difference detection pixel from data of a close image
generation pixel by regarding the position of the phase
difference detection pixel as a defective pixel. Further,
an image generation pixel neighbor to the phase
difference detection pixel has a different property from
the image generation pixel neighbor only to the image
5 generation pixel, and needs perform correction upon
generation of an image. This results in requiring image
processing of generating images corresponding to phase
difference detection pixels and images corresponding to
image generation pixels close to the phase difference
10 detection pixels, thereby increasing a load of this image
processing.
[0007]
The present invention is made in light of such a
situation, and an object of the present invention is to
15 reduce a load of processing related to image generation
when an image capture element used to detect a phase
difference and generate an image generates an image.
SOLUTIONS TO PROBLEMS
20 [0008]
The present invention is made to solve the above
problem, and a first aspect of the present invention has:
a plurality of phase difference detection pixels which
generate signals for performing adjusted focus decision
25 by way of phase difference detection; and a plurality of
image generation pixels which generate signals for
generating an image, and a first pixel group formed by
arranging part of phase difference detection pixels of
the plurality of phase difference detection pixels in a
30 specific direction and a second pixel group formed by
arranging part of image generation pixels of the
plurality of pixel generation pixels in the specific
direction are alternately arranged in an orthogonal
direction orthogonal to the specific direction. By this
means, an effect is provided that the first pixel group
5 formed by arranging the phase difference detection pixels
in the specific direction and the second pixel group
formed by arranging the image generation pixels are
alternately arranged.
[0009]
10 Further, according to this first aspect, each of
the plurality of image generation pixels may have a fixed
ratio of the phase difference detection pixels and the
image generation pixels for each neighboring pixel in an
area of the image capture element which receives subject
15 light. By this means, an effect is provided that a rate
of the phase difference detection pixels and the image
generation pixels is fixed for each pixel neighbor to the
image generation pixels.
[OOlO]
20 Further, according to this first aspect, the first
pixel group may have a plurality of phase difference
detection pixels forming one or a plurality of lines, and
the second pixel group may have a plurality of image
generation pixels forming one or two lines. By this
25 means, an effect is provided that the first pixel group
has a plurality of phase difference detection pixels
forming one or a plurality of lines and the second pixel
group has a plurality of image generation pixels forming
one or two lines.
30 [OOll]
Further, according to this first aspect, the
specific direction may a reading direction when data
generated by the phase difference detection pixels and
the image generation pixels is read from the phase
difference detection pixels and the image generation
5 pixels. By this means, an effect is provided that the
first pixel group formed by arranging the phase
difference detection pixels in the reading direction and
the second pixel group formed by arranging the image
generation pixels in the reading direction are
10 alternately arranged.
[0012]
Further, according to this first aspect, the first
pixel group may have a plurality of phase difference
detection pixels forming one line, the second pixel group
15 may have a plurality of image generation pixels forming
one line, and two continuous image generation pixels of
the plurality of image generation pixels which have color
filters of an identical property and are arranged in the
specific direction may form a pair of image generation
20 pixels, and each pixel may be arranged using the pair of
image generation pixels as pixel units. By this means,
an effect is provided that the two continuous image
generation pixels which have color filters of the
identical property and are arranged in the specific
25 direction form a pair of image generation pixels, and
each pixel is arranged using the pair of image generation
pixels as pixel units. Further, in this case, the
plurality of image generation pixels may be arranged in
Bayer alignment in the pixel units in the image capture
30 element. By this means, an effect is provided that the
pixel units of the image generation pixels are arranged
in Bayer alignment.
[0013]
Further, according to this first aspect, two phase
difference detection pixels of the plurality of phase
5 difference detection pixels which perform pupil division
in an identical direction and receive lights divided in
one way of the identical direction may form a pair of
phase difference detection pixels as two continuous phase
difference detection pixels arranged in the specific
10 direction, and each pixel may be arranged using the pair
of the phase difference detection pixels as pixel units.
By this means, an effect is provided that the two
continuous phase difference detection pixels arranged in
the specific direction fon a pair of phase difference
15 detection pixels, and each pixel is arranged using the
pair of phase difference detection pixels as pixel units.
[0014]
Further, according to this first aspect, two
continuous light reception elements of light reception
20 elements of the plurality of image generation pixels
which have color filters of an identical property and
which are arranged in the specific direction may form a
pair of light reception elements, and each pixel may be
arranged using two pixels related to the pair of light
25 reception elements as pixel units. By this means, an
effect is provided that the two light reception elements
are provided to the image generation pixel as a pair of
light reception element.
[0015]
3 0 Further, according to this first aspect, two light
reception elements of light reception elements of the
p l u r a l i t y of phase difference detection pixels which
perform pupil division i n an i d e n t i c a l d i r e c t i o n and
receive l i g h t divided i n one way of the i d e n t i c a l
direction may form a pair of l i g h t reception elements,
5 and each element may be arranged using two p i x e l s r e l a t e d
t o the pair of l i g h t reception elements as a p i x e l u n i t .
By t h i s means, an effect is provided that the two l i g h t
reception elements are provided t o the phase difference
detection pixel as a pair of l i g h t reception elements.
10 [0016]
Further, according t o t h i s first aspect, the f i r s t
pixel group may have a f i r s t l i n e formed by arranging in
the s p e c i f i c direction the phase difference detection
pixels t o be pupil-divided i n the s p e c i f i c direction and
15 a second l i n e formed by arranging in the s p e c i f i c
direction the phase difference detection pixels t o be
pupil-divided i n the orthogonal direction, and the f i r s t
l i n e and the second l i n e may be a l t e r n a t e l y arranged
across the second pixel group. By t h i s means, an effect
20 is provided that the f i r s t l i n e of the phase difference
detection pixels t o be pupil-divided in the s p e c i f i c
direction and the second l i n e of the phase difference
detection pixels t o be pupil-divided in the orthogonal
direction a r e a l t e r n a t e l y arranged across the second
25 pixel group. Further, i n t h i s case, the phase difference
detection pixel may have a p l u r a l i t y of phase difference
detection pixels corresponding t o a p l u r a l i t y of e x i t
pupils provided a t d i f f e r e n t positions i n an o p t i c a l a x i s
direction, and the f i r s t l i n e may be formed by arranging
30 phase difference detection pixels of the p l u r a l i t y of
phase difference detection pixels having the e x i t pupils
provided a t an i d e n t i c a l position. By t h i s means, an
e f f e c t is provided t h a t the f i r s t l i n e is formed by
arranging the phase d i f f e r e n c e d e t e c t i o n pixels of a
p l u r a l i t y of phase d i f f e r e n c e d e t e c t i o n pixels having the
5 e x i t pupils provided a t t h e i d e n t i c a l position. Further,
i n t h i s case, the p l u r a l i t y of phase d i f f e r e n c e d e t e c t i o n
pixels may have a p l u r a l i t y of phase d i f f e r e n c e d e t e c t i o n
pixels corresponding t o a p l u r a l i t y of e x i t pupils
provided a t d i f f e r e n t p o s i t i o n s i n an a x i a l d i r e c t i o n ,
10 and the second l i n e may be formed by arranging phase
d i f f e r e n c e d e t e c t i o n pixels having the e x i t pupils
provided a t an i d e n t i c a l position, a t a p o s i t i o n
i d e n t i c a l t o a p o s i t i o n i n the s p e c i f i c d i r e c t i o n . By
t h i s means, an e f f e c t is provided t h a t the second l i n e is
15 formed such t h a t the phase d i f f e r e n c e d e t e c t i o n p i x e l s
having the pupil e x i s t s provided a t the i d e n t i c a l
p o s i t i o n are provided a t the same p o s i t i o n as the
p o s i t i o n i n t h e s p e c i f i c d i r e c t i o n .
[0017]
20 Further, according t o a second aspect of the
present invention, an image capture element has: a
p l u r a l i t y of phase d i f f e r e n c e d e t e c t i o n pixels which
generate s i g n a l s for performing adjusted focus decision
by way of phase difference detection; and a p l u r a l i t y of
25 image generation pixels which generate s i g n a l s f o r
generating an image, and each of the p l u r a l i t y of image
generation pixels has a fixed r a t i o of the phase
d i f f e r e n c e d e t e c t i o n pixels and the image generation
pixels for each neighboring p i x e l i n an area of the image
30 capture element which r e c e i v e s s u b j e c t l i g h t . By t h i s
means, an e f f e c t is provided t h a t a r a t e of the phase
d i f f e r e n c e d e t e c t i o n p i x e l s and the image generation
pixels is fixed f o r each pixel neighbor t o the image
generation p i x e l s .
[0018]
5 Further, according t o a t h i r d aspect of the present
invention, an imaging device has: an image capture
element which has a p l u r a l i t y of phase difference
detection pixels which generate s i g n a l s f o r performing
adjusted focus decision by way of phase difference
10 detection, and a p l u r a l i t y of image generation pixels
which generate s i g n a l s f o r generating an image, and i n
which a f i r s t p i x e l group formed by arranging p a r t of
phase d i f f e r e n c e d e t e c t i o n pixels of the p l u r a l i t y of
phase d i f f e r e n c e d e t e c t i o n pixels i n a s p e c i f i c d i r e c t i o n
15 and a second p i x e l group formed by arranging p a r t of
image generation pixels of the p l u r a l i t y of p i x e l
generation pixels i n the s p e c i f i c d i r e c t i o n are
a l t e r n a t e l y arranged i n an orthogonal d i r e c t i o n
orthogonal t o t h e s p e c i f i c d i r e c t i o n ; an focus adjustment
20 decision u n i t which performs adjusted focus decision by
way of phase d i f f e r e n c e d e t e c t i o n based on the s i g n a l s
generated by the phase d i f f e r e n c e d e t e c t i o n p i x e l s ; and
an image generation u n i t which generates an image based
on t h e s i g n a l s generated by the image generation p i x e l s .
25 By t h i s means, an e f f e c t is provided t h a t adjusted focus
is performed by way of phase d i f f e r e n c e d e t e c t i o n and
image generation is performed by using the image capture
element i n which the f i r s t pixel group formed by
arranging the phase d i f f e r e n c e d e t e c t i o n p i x e l s i n the
30 s p e c i f i c d i r e c t i o n and the second pixel group formed by
forming the image generation p i x e l s i n t h e s p e c i f i c group
are alternately arranged.
EFFECTS OF THE INVENTION
[0019]
5 The present invention can provide a good effect of
reducing a load of processing related to image generation
when an image capture element used to detect a phase
difference and generate an image generates an image.
10 BRIEF DESCRIPTION OF DRAWINGS
[0020]
Fig. 1 is a block diagram illustrating an example
of a function and a configuration of an imaging device
100 according to a first embodiment of the present
15 invention.
Fig. 2 is a cross-sectional view schematically
illustrating an example of a position of a pellicle
mirror 160 of the imaging device 100 according to the
first embodiment of the present invention.
20 Fig. 3 is a schematic view illustrating an example
of an arrangement of light reception elements of a second
image sensor 200 according to the first embodiment of the
present invention.
Fig. 4 is a top view schematically illustrating an
25 example of an arrangement of pixels in an area 340 of the
second image sensor 200 according to the first embodiment
of the present invention and an example of an arrangement
of pixels in a conventional image sensor.
Fig. 5 is a schematic view illustrating an internal
30 configuration of the pixel of the second image sensor 200
according to the first embodiment of the present
invention, and an internal configuration of the pixel of
the conventional image sensor.
Fig. 6 is a schematic view illustrating pupil
division of a phase difference detecting pixel Dl and a
5 phase difference detecting pixel D2 according to the
first embodiment of the present invention.
Fig. 7 is a schematic view illustrating pupil
division of a phase difference detecting pixel D3 and a
phase difference detecting pixel D4 according to the
10 first embodiment of the present invention.
Fig. 8 is a schematic view illustrating pixels
neighbor to image generating pixels of the second image
sensor 200 according to the first embodiment of the
present invention and pixels neighbor to image generating
15 pixels of the conventional image sensor.
Fig. 9 is a schematic view illustrating a captured
image generated based on a signal of the second image
sensor 200 according to the first embodiment of the
present invention and a captured image generated based on
20 a signal of the conventional image sensor.
Fig. 10 is a graph illustrating an example of a
data reading speed of the second image sensor 200
according to the first embodiment of the present
invention and an example of a data reading speed of the
25 conventional image sensor.
Fig. 11 is a view illustrating an example of an
arrangement of light reception elements of a second image
sensor in which positions of a pair of phase difference
detecting pixels are opposite to those of the first
30 embodiment according to a modified example of the first
embodiment of the present invention.
Fig. 12 is a view illustrating an arrangement of
light reception elements of the second image sensor in
which only phase difference detection pixels to be pupildivided
in a reading direction are arranged in a row of
5 the phase difference detection pixels according to the
modified example of the first embodiment of the present
invention.
Fig. 13 is view illustrating an example of an
arrangement of the light reception elements of the second
10 image sensor which is different from Fig. 12 and in which
only phase difference detecting pixels to be pupildivided
in the reading direction are arranged in a row of
the phase difference detecting pixels according to the
modified example of the first embodiment of the present
15 invention.
Fig. 14 is a view illustrating an example of an
arrangement of the light reception elements of the second
image sensor in which rows of phase difference detecting
pixels and rows of image generating pixels are
20 alternately arranged every two other rows according to
the modified example of the first embodiment of the
present invention.
MODE FOR CARRYING OUT THE INVENTION
25 [0021]
Hereinafter, a mode (hereinafter, "embodiment" ) for
implementing the present invention will be described.
The embodiment will be described in the following order.
1. First Embodiment (Image capture control: an
30 example where lines of phase difference detecting pixels
and lines of image generating pixels are alternately
arranged)
2. Modified Example
[0022]
<1. First Embodiment>
5 [Example of Function and Configuration of Imaging
Device ]
Fig. 1 is a block diagram illustrating an example
of a function and a configuration of an imaging device
100 according to a first embodiment of the present
10 invention. The imaging device 100 is an imaging device
which captures an image of a subject, generates image
data (captured image) and records the generated image
data as image content (still image content or movie
content). In addition, an example will be mainly
15 described below where still image content (still image
file) is recorded as image content (image file).
[0023]
The imaging device 100 has a lens unit 110, an
operation reception unit 120, a control unit 130, a first
20 image sensor 140 and a first signal processing unit 150.
Further, the imaging device 100 has a pellicle mirror 160,
a second image sensor 200, a second signal processing
unit 170, a memory unit 181, a display unit 182, an focus
adjustment decision unit 183 and a drive unit 184.
25 [0024]
The lens unit 110 condenses light (subject light)
from a subject. This lens unit 110 has a zoom lens 111,
a diaphragm 112 and a focus lens 113.
[0025]
3 0 The zoom lens 111 adjusts the magnification power
of the subject included in a captured image by changing a
focal distance while being driven by the drive unit 184
and moved in the optical direction.
[0026]
The diaphragm 112 is a blocking material for
5 adjusting the amount of subject light incident on the
first image sensor 140 and the second image sensor 200 by
changing the degree of aperture while being driven by the
drive unit 184.
[0027]
10 The focus lens 113 adjusts the focus by moving in
the optical direction while being driven by the drive
unit 184.
[00281
The operation reception unit 120 receives an
15 operation from a user. When, for example, a shutter
button 121 (illustrated in Fig. 2) is pushed, this
operation reception unit 120 supplies a signal related to
this pushing to the control unit 130 as an operation
signal.
20 [0029]
The control unit 130 controls the operation of each
unit in the imaging device 100. For example, when
receiving an operation signal for starting recording a
still image in response to pushing of the shutter button
25 121, this control unit 130 supplies a signal related to
execution of recording of a still image (still image
capturing operation signal) to the first signal
processing unit 150. Further, to display a live view on
a display unit 182, the control unit 130 supplies a
30 signal (live view display signal) for generating a live
view image based on the signal outputted from the second
image sensor 200 to the second signal processing unit 170.
Meanwhile, the live view refers to real time display of
an image of a subject incident on the imaging device 100.
Further, when performing adjusted focus decision
5 according to a phase difference detection system, the
control unit 130 supplies a signal (phase difference
detecting operation signal) indicating an operation
(phase difference detecting operation) for performing
this adjusted focus decision, to the second signal
10 processing unit 170. Meanwhile, the phase difference
detection system refers to a focus detection system which
forms a pair of images by pupil-dividing light having
passed an image capture lens, measuring an interval
between the formed images (the amount of misalignment
15 between the images (detecting the phase difference) and
detecting the degree of focus adjustment.
[0030]
The pellicle mirror 160 divides subject light
condensed through the lens unit 110 into two. This
20 pellicle mirror 160 is, for example, a semi-transparent
mirror, and divides subject light into two by reflecting
30% of the subject light. The pellicle mirror 160
supplies one of the divided lights to the first image
sensor 140, and supplies the other to the second image
25 sensor 200.
[0031]
The first image sensor 140 is an image capture
element which receives one of the subject light divided
by the pellicle mirror 160 and photoelectrically converts
30 the received subject light into an electric signal. This
first image sensor 140 is realized by, for example, a
CMOS (Complementary Metal Oxide Semiconductor) sensor.
In the first image sensor 140, only pixels (image
generation pixels) which generate signals for generating
a captured image based on the received subject light are
5 arranged in Bayer alignment. The first image sensor 140
supplies the electric signal resulting from photoelectric
conversion to the first signal processing unit 150.
[0032]
The first signal processing unit 150 applies
10 various signal processing to the electric signal supplied
from the first image sensor 140. When, for example,
receiving a supply of the still image capturing operation
signal from the control unit 130, this first signal
processing unit 150 generates data of a still image
15 (still image data). Further, the first signal processing
unit 150 supplies this generated image data to the memory
unit 181 and has the memory unit 181 store this image
data.
[0033]
20 The memory unit 181 records image data supplied
from the first signal processing unit 150 as image
content (image file). For example, removable recording
media (one or a plurality of recording media) such as
disks including, for example, DVDs (Digital Versatile
25 Disk) or semiconductor memories including, for example,
memory cards can be used for this memory unit 181.
Further, these recording media may be built in the
imaging device 100 or may be detachable from the imaging
device 100.
30 100341
The second image sensor 200 is an image capture
element which receives one of the subject light divided
by the pellicle mirror 160 and photoelectrically converts
the received subject light into an electric signal. This
second image sensor 200 is realized by, for example, a
5 CMOS sensor similar to the first image sensor 140. In
the second image sensor 200, the image generation pixels
and pixels (phase difference detection pixels) which
generate signals for performing phase difference
detection are arranged. In addition, the second image
10 sensor 200 will be described with reference to Figs. 3 to
10. The second image sensor 200 supplies the electric
signal resulting from photoelectric conversion to the
second signal processing unit 170. In addition, the
second image sensor 200 is an example of the image
15 capture element recited in the claims.
[0035]
The second signal processing unit 170 applies
various signal processing to the electric signal supplied
from the second image sensor 200. When, for example,
20 receiving a supply of the phase difference detection
operation signal from the control unit 130, this signal
processing unit 170 generates data (phase difference
detection data) for detecting a phase difference based on
output signals from the phase difference detection pixels
25 in the second image sensor 200. Further, the second
signal processing unit 170 supplies the generated phase
difference detection data to the focus adjustment
decision unit 183. Furthermore, when receiving a supply
of a live view display signal from the control unit 130,
30 the second signal processing unit 170 generates data of
the live view image (live view image data) based on
output signals from the image generation pixels in the
second image sensor 200. Still further, the second
signal processing unit 170 supplies this generated live
view image data to the display unit 182, and has a
5 display screen of the display unit 182 display the live
view. In addition, the second signal processing unit 170
is an example of an image generation unit recited in the
claims.
100361
10 The display unit 182 displays an image based on the
image data supplied from the second signal processing
unit 170. This display unit 182 is realized by, for
example, a color liquid crystal panel. When, for example,
receiving a supply of the live view image data from the
15 second signal processing unit 170, this display unit 182
displays the live view image on the display screen.
[0037]
The focus adjustment decision unit 183 decides
whether or not the focus is adjusted with respect to an
20 object (focus adjustment target) which is a target to
focus upon based on phase difference detection data
supplied from the second signal processing unit 170.
When the focus is adjusted on the object (focus
adjustment target) in an area (focus area) in which
25 focusing is performed, this focus adjustment decision
unit 183 supplies information indicating that the focus
is adjusted to the drive unit 184 as focus adjustment
decision result information. Further, when the focus is
not adjusted upon the focus adjustment target, this focus
30 adjustment decision unit 183 calculates the amount of
misalignment of focus (defocus amount) and supplies
information indicating the calculated amount of defocus
to the drive unit 184 as focus adjustment decision result
information.
100381
5 The drive unit 184 drives the zoom lens 111, the
diaphragm 112 and the focus lens 113. For example, the
drive unit 184 calculates the driving amount of the focus
lens 113 based on the focus adjustment decision result
information outputted from the focus adjustment decision
10 unit 183 and moves the focus lens 113 according to the
calculated driving amount. When the focus is adjusted,
this drive unit 184 maintains the current position of the
focus lens 113. Further, when the focus is defocused,
the drive unit 184 calculates the driving amount (moving
15 distance) based on the focus adjustment decision result
information indicating the defocus amount and position
information of the focus lens 113, and moves the focus
lens 113 according to the driving amount.
[0039]
20 [Example of Position of Pellicle Mirror]
Fig. 2 is a cross-sectional view schematically
illustrating an example of a position of the pellicle
mirror 160 of the imaging device 100 according to the
first embodiment of the present invention. In addition,
25 the imaging device 100 will be described using Fig. 2 as
a single-lens reflex camera.
[0040]
In Fig. 2, the cross-sectional view of the imaging
device 100 indicates the shutter button 121, the display
30 screen (liquid crystal display 182a) of the display unit
182, the pellicle mirror 160, the first image sensor 140
and the second image sensor 200. Further, Fig. 2
illustrates an optical axis (optical axis L12) in a lens
of the lens unit 110 and two lines (lines L11 and L13)
indicating a range in which subject light passes. In
5 addition, the range sandwiched by the lines L11 and L13
indicates a range in which lights incident on the first
image sensor 140 and the second image sensor 200 pass.
[0041]
The pellicle mirror 160 is arranged to divide
10 subject light incident on the imaging device 100 into two.
For example, the pellicle mirror 160 is arranged at 45
degrees with respect to the optical axis L12. By this
means, the pellicle mirror 160 reflects part of subject
light (for example, 30%) upward.
15 [0042]
The first image sensor 140 is arranged vertically
with respect to the optical axis L12 ahead of the
pellicle mirror 160 (a traveling direction of subject
light) to receive subject light having passed the
20 pellicle mirror 160.
[0043]
The second image sensor 200 is arranged
horizontally with respect to the optical axis L12 above
the pellicle mirror 160 (as the pellicle mirror 160 is at
25 45 degrees with respect to the optical axis L12) to
receive the subject light reflected by the pellicle
mirror 160.
[0044]
By this means, in the imaging device 100, the
30 pellicle mirror 160 is arranged to divide incident
subject light into two. Further, the first image sensor
140 and the second image sensor 200 are arranged to
receive the two divided subject lights.
[0045]
[Example of Arrangement of Light Reception Elements
5 of Second Image Sensor]
Fig. 3 is a schematic view illustrating an example
of an arrangement of light reception elements of the
second image sensor 200 according to the first embodiment
of the present invention. According to the first
10 embodiment of the present invention, one image generation
pixel has two light reception elements, and one phase
difference detection pixel also has two light reception
elements. Hence, an arrangement of the light reception
elements will be described with reference to Fig. 3.
15 [0046]
In addition, Fig. 3 will be described assuming xy
axes where left and right directions is a y axis and up
and down directions are an x axis direction. Further, in
Fig. 3, an upper left end is the original point of the xy
20 axes, a direction from the top to the bottom is a + side
of the x axis and a direction from the left to the right
is a + side of the y axis. In addition, a reading
direction of a signal in this second image sensor 200 is
an x axis direction (read in row units). In addition, a
25 reading direction of a signal in the second image sensor
200 is an example of a specific direction recited in the
claims.
[0047]
For ease of description, Fig. 3 will be described
30 using an area (area 210) of part of light reception
elements (light reception elements of sixteen rows and
sixteen columns) of light reception elements of each
pixel forming the second image sensor 200. In addition,
according to an arrangement of the light reception
elements in the second image sensor 200, a pixel
5 arrangement (a pixel arrangement corresponding to the
area 210) corresponding to this unit is repeated in the x
direction and the y direction using the pixel arrangement
indicated in the area 210 as one unit.
[0048]
10 Fig. 3 illustrates one light reception element as
one circle. Further, light reception elements of the
image generation pixel are indicated by circles with
references (R (red), G (green) and B (blue) ) indicated
therein and representing color filters provided in the
15 light reception elements. Furthermore, light reception
elements of the phase difference detection pixels are
indicated by circles including portions including filled
sides (gray semi-circles) which are the same as the side
on which incident light is blocked by the light block
20 unit. In addition, as to the light reception elements of
the phase difference pixel, light reception elements
corresponding to exit pupils of four positions (positions
dl to d4) are indicated together with reference numerals
(Dl to D4). Further', alphabets (a to d) of the reference
25 numerals of the light reception elements of the phase
difference detection pixel indicate a side on which
incident light is blocked by the light block unit (a is a
- side of the x axis, b is the + side of the x axis, c is
the + side of the y axis and d is the - side of the y
30 axis). For example, Dla is a light reception element
which blocks right half light of light pupil-divided to
the left and right (the + and - sides of the x axis) by
the exit pupil at the position dl and receives the left
half pupil-divided light. In addition, the phase
difference detection pixel will be described with
5 reference to Figs. 4 to 8.
[0049]
Hereinafter, an arrangement of pixels in the second
image sensor 200 will be described.
[0050]
10 In the second image sensor 200, rows (lines) in
which light reception elements of image generation pixels
are arranged and rows (lines) in which light reception
pixels of phase difference detection pixels are arranged
are alternately arranged. That is, as illustrated in Fig.
15 3, the image generation pixel, the phase difference
detection pixel, the image generation pixel, the phase
difference detection pixel and ... are alternately
arranged in the y axis direction. In addition, the rows
in which the light reception elements of the image
20 generation pixels are arranged are an example of a second
image group recited in the claims. Further, the rows in
which the light reception elements of the phase
difference detection pixels are arranged are an example
of a first pixel group recited in the claims.
25 [0051]
Furthermore, the light reception elements of the
image generation pixels are arranged such that two light
reception elements in which color filters of the same
color are arranged continue in the x axis direction (in
30 Fig. 3, RR, GG and BB continue in the x axis direction).
In addition, although these two continuous light
reception elements form one image generation pixel with
the first embodiment of the present invention, this will
be described with reference to Fig. 6.
[0052]
5 The light reception elements of the phase
difference detection pixels are arranged such that two
light reception pixels in which light is blocked on the
identical side continue the x axis direction (in Fig. 3,
for example, DlaDla and DlbDlb continue in the x axis
10 direction). In addition, although these two continuous
light reception elements form one phase difference
detection pixels with the first embodiment of the present
invention, this will be described with reference to Fig.
6.
15 [0053]
Further, the light reception elements of the phase
difference detection pixels are arranged such that the
rows in which only light reception elements in which a
positional relationship between a light blocking side and
20 a light incident side of subject light is the x axis
direction (reading direction) are arranged and rows in
which only the light reception elements in which a
positional relationship between the light blocking side
and the light incident side is the y axis direction are
25 alternately arranged. That is, as for the light
reception elements of phase difference detection pixels,
phase difference detection pixels to be pupil-divided in
the identical direction (a reading direction or a
direction orthogonal to the reading direction) are
30 arranged in row units. In Fig. 3, horizontal Dl row 321,
horizontal D2 row 323, horizontal D3 row 325 and
horizontal D4 row 327 are indicated as rows in which only
light reception elements in the x axis direction are
arranged. Further, a vertical detection row 322, a
vertical detection row 324, a vertical detection row 326
5 and a vertical detection row 328 are indicated as rows in
which only light reception elements in the y axis
direction are arranged.
[0054]
In the rows in which only the light reception
10 elements in the x axis direction are arranged, the light
reception elements having exit pupils provided at the
same position are arranged. That is, only Dla and Dlb
are arranged in horizontal Dl row 321, only D2a and D2b
are arranged in horizontal D2 row 323, only D3a and D3b
15 are arranged in horizontal D row 325 and only D4a and D4b
are arranged in horizontal D4 row 327. Further, in the
rows in which only light reception elements in the x axis
direction are arranged, phase difference detection pixels
of light reception elements a (which are in the x axis
20 direction and on the - side of which light is blocked)
and phase difference detection pixels of light reception
elements b (which are in the x axis direction and on the
+ side of which light is blocked) are alternately
arranged. For example, in horizontal Dl row 321 in Fig.
25 3, the two light reception elements DlbDlb are neighbor
to the two light reception elements DlaDla (the two light
reception elements form one phase difference detection
pixel, and therefore the phase difference detection pixel
Dla is neighbor to the phase difference detection pixel
30 Dlb). That is, the light reception elements (light
reception elements of a and b types) to be pupil-divided
in the reading direction (x axis direction in Fig. 3) of
the second image sensor 200 are arranged to be capable of
detecting the phase difference only based on a signal of
the phase difference detection pixels arranged in one row.
5 By this means, when the reading direction (x axis
direction) is pupil-divided, it is possible to detect the
phase difference only from data of the phase difference
detection pixels in one row of the rows of a plurality of
phase difference detection pixels.
10 [0055]
In rows in which only the light reception elements
in the y axis direction are arranged, four pairs (pairs
of Dl and D2) with respect to four exit pupil positions
are sequentially arranged with respect to pairs of two
15 light reception elements (DlcDlc and DldDld) which
receive light on the opposite side with respect to the
position of the identical exit pupil. Further, in the
rows in which only the light reception elements in the y
axis direction are arranged, the light reception elements
20 are identical in the y axis direction with respect to the
rows in which only the other light reception elements in
the y axis direction are arranged. That is, vertical Dl
row 311 in Fig. 3 indicates a column in which light
reception elements positioned in this column in a
25 vertical detection row are Dlc and Dld. Similarly, D2
column 312 refers to a column in which light reception
elements are D2c and D2d, vertical D3 column 313 refers
to a column in which light reception elements are D3c and
D3d and vertical D4 column 314 refers to a column in
30 which light reception elements are D4c and D4d. That is,
phase difference detection pixels to be pupil-divided in
a direction (the y axis direction in Fig. 3) which is
different at 90 degrees from the reading direction of the
second image sensor 200 are arranged to be capable of
detecting the phase difference based on signals of the
5 phase difference detection pixels (four columns of the
light reception elements) arranged in two continuous
columns. Further, the rows of the phase difference
detection pixels to be pupil-divided in the y axis
direction and the rows of the phase difference detection
10 pixels to be pupil-divided in the x axis direction are
alternately arranged across the rows of the image
generation pixels, so that an interval between the rows
of the phase difference detection pixels to be pupildivided
in the y axis direction is narrow.
15 [0056]
Thus, in the second image sensor 200, the rows in
which the image generation pixels are arranged and the
rows in which the phase difference detection pixels are
arranged are alternately arranged.
20 [0057]
Next, pixels included in an area 340 (4 x 4 light
reception elements) will be focused upon and described
with reference to Fig. 4 as to pixels according to the
first embodiment of the present invention,
25 [0058]
[Example of Arrangement of Pixels of Second Image
Sensor]
Fig. 4 is a top view schematically illustrating an
example of an arrangement of pixels in the area 340 of
30 the second image sensor 200 according to the first
embodiment of the present invention and an example of an
arrangement of pixels in a conventional image sensor. In
addition, Fig. 4 will be described assuming xy axes where
left and right directions is a y axis and up and down
directions are a x axis direction. Further, the signal
5 reading direction is the x axis direction (read in row
units).
[0059]
Fig. 4(a) illustrates a pixel arrangement of three
pixel groups (pixel groups 391 to 393) schematically
10 illustrating image generation pixels in a conventional
image sensor to which image generation pixels and phase
difference detection pixels are provided and a pixel
arrangement of the phase difference detection pixels in
the conventional image sensor.
15 [0060]
The pixel group 391 is pixels of two rows and two
columns indicating a pixel arrangement of the image
generation pixels in the conventional image sensor to
which both of the image generation pixels and the phase
20 difference detection pixels are provided. In the pixel
group 391, a pixel (R pixel 291) which receives red light
by means of a color filter which allows transmission of
red light is arranged on an upper left, and pixels (G
pixel 292) which receive green light by means of a color
25 filter which allows transmission of green light are
arranged on an upper right and a lower left. Further, in
the pixel group 391, a pixel (B pixel 293) which receives
blue light by means of a color filter which allows
transmission of blue light is arranged on a lower right.
30 Thus, in the image generation pixels of the conventional
image sensor, three colors of blue, green and red are
arranged in Bayer alignment. Further, with the image
generation pixels of the conventional image sensor,
pixels provided in the arrangement indicated by the pixel
group 391 form most part of the image sensors.
5 [0061]
The pixel group 392 is pixels of one row and four
columns indicating a pixel arrangement of the phase
difference detection pixels provided in the x axis
direction in the conventional image sensor. In the pixel
10 group 392, a phase difference detection pixel (phase
difference detection pixel (Dla) 294) on the left side of
which light is blocked, and a phase difference detection
pixel (phase difference detection pixel (Dlb) 295) on the
right side of which light is blocked are alternately
15 arranged in the x axis direction.
[0062]
The pixel group 393 includes pixels of four rows
and one column indicating a pixel arrangement of the
phase difference detection pixels provided in the y axis
20 direction in the conventional image sensor. In the pixel
group 393, the phase difference detection pixel (phase
difference detection pixel (Dlc) 296) on an upper side of
which light is blocked and a phase difference detection
pixel (phase difference detection pixel (Dld) 297) on a
25 lower side of which light is blocked are alternately
arranged in the y axis direction.
[0063]
Meanwhile, positions of phase difference detection
pixels in the conventional image sensor will be described.
30 In the conventional image sensor, it is necessary to
supplement image information about the positions of the
phase difference detection pixels which cannot generate
signals which can be used to generated images, and
therefore the phase difference detection pixels the
number of which is as small as possible are arranged.
5 That is, in the conventional image sensor, most of pixels
are pixels indicating the pixel group 391, and only
pixels at sites at which phase differences are phase
difference detection pixels provided in arrangements as
indicated by the pixel group 392 and the pixel group 393.
10 COO641
Fig. 4(b) illustrates pixels corresponding to the
area 340 in Fig. 3 as a pixel arrangement in the second
image sensor 200 according to the first embodiment of the
present invention. Fig. 4(b) illustrates a pixel (R
15 pixel 220) which has two light reception elements which
receive red (R) light and a pixel (G pixel 230) which has
two light reception elements which receive green (G)
light. Further, Fig. 4(b) illustrates a pixel (B pixel
240) which has two light reception elements) which
20 receive blue (B) light as an image generation pixel.
Furthermore, Fig. 4(b) a pixel (phase difference
detection pixel (Dla) 251) which has two light reception
elements (Dla) on the left side of which light is blocked
and a pixel (phase difference detection pixel (Dlb) 252)
25 which has two light reception elements (Dlb) on the right
side of which light is blocked. Still further, Fig. 4(b)
illustrates a pixel (phase difference detection pixel
(Dlc) 253) which has two light reception elements (Dlc)
on the upper side of which is blocked and a pixel (phase
30 difference detection pixel (Dld) 254) which has two light
reception elements (Dla) on the lower side of which light
is blocked).
[0065]
Thus, the image generation pixels and the phase
difference detection pixels of the second image sensor
5 200 each have two light reception elements. In addition,
in view only from the image generation pixels except the
rows in which the light reception elements of the phase
difference detection pixels are arranged, R pixel 220 is
provided at the upper left, the G pixel 230 are provided
10 at the upper right and the lower left and the B pixel 240
is provided on the lower right in Bayer alignment similar
to Fig. 4(a). In the second image sensor 200, all pixels
are formed in the arrangement indicated by the area 210,
and therefore the arrangement of only the image
15 generation pixels except the rows in which light
reception elements of the phase difference detection
pixels is uniform Bayer alignment.
[0066]
[Configuration Example of Image Sensor]
20 Fig. 5 is a schematic view illustrating an internal
configuration of the pixel of the second image sensor 200
according to the first embodiment of the present
invention, and an internal configuration of the pixel of
the conventional image sensor.
25 [0067]
Fig. 5(a) illustrates a schematic view of the image
generation pixels and the phase difference detection
pixels arranged in the conventional image sensor to which
both of the image generation pixels and the phase
30 difference detection pixels are provided. Fig. 5(a) will
be described assuming an area in which a row in which
pixel generation pixels are arranged and a row in which
phase difference detection pixels are arranged. Fig.
5 (a) illustrates the R pixels 291, the G pixels 292, the
phase difference detection pixels (Dla) 294), the phase
5 difference detection pixels (Dlb) 295 and signal lines
461 to 468.
[0068]
The R pixel 291 is a pixel which has a color filter
which allows transmission of red light, and has a light
10 reception element 410, a ED (Floating Diffusion) 442) and
an amplifier 443).
[0069]
The light reception element 410 converts
(photoelectrically converts) the received light into an
15 electric signal to generate an electric signal having the
intensity matching the amount of the received light.
This light reception element 410 is formed with, for
example, a photo diode (PD) .
[0070]
20 The ED 442 detects an electric charge of the light
reception element. This FD 442 converts the detected
electric charge into a voltage, and supplies the voltage
to the amplifier 443.
[0071]
25 The amplifier 443 amplifies the voltage supplied
from the ED 442. This amplifier 443 supplies the
amplified voltage to the signal line 461.
[0072]
In addition, the G pixel 292 is the same as the R
30 pixel 291 except that a color filter which allows
transmission of green light is provided instead of the
color filter which allows transmission of red light, and
therefore will not be described.
[0073]
Further, the phase difference detection pixel (Dla)
5 294 and the phase difference detection pixel (Dlb) 295
are the same as the R pixel 291 except that there is not
a color filter and light is blocked with respect to half
of the light reception elements by the light block unit
(for example, part of wirings).
10 [0074]
The signal lines 461 to 468 read signals generated
by each pixel connected to these signal lines. In the
second image sensor 200, data generated by the pixels is
sequentially read in the horizontal direction (column
15 direction) which is a reading direction through these
signal lines 461 to 468. When, for example, data of
pixels in a row (a row in which the R pixel 291 and the G
pixels 292 are alternately arranged) of the image
generation pixels, the row of the image generation pixels
20 is set (set in the y axis direction) as a row to read
data from the pixels. Further, columns to read data from
pixels are sequentially set (set in the x axis direction),
and data is sequentially read from the pixels. Assuming
that data is sequentially read from the left, data of the
25 image generation pixel (R pixel 291) connected to the
signal line 461 is read first in Fig. 5(a). Next, data
of the pixel generation pixel (G pixels 292) connected to
the signal line 462 is read and then data is read from
the image generation pixels connected to the signal line
30 463, that is, data is sequentially read.
[0075]
Thus, the conventional image sensor is formed with
pixels (image generation pixels and phase difference
detection pixels) which each have the light reception
element 410, the ED 442 and the amplifier 443.
5 [0076]
Fig. 5(b) is a schematic view illustrating image
generation pixels and phase difference detection pixels
arranged in the second image sensor 200 according to the
first embodiment of the present invention. Fig. 5(b)
10 will be described assuming that eight and two light
reception elements (four and two pixels) in the top row
and the second row from the top of the area 210
illustrated in Fig. 3. Fig. 5(b) illustrates the R
pixels 220, the G pixels 230, the phase difference
15 detection pixels (Dla) 253, the phase difference
detection pixels (Dlb) 254, and the signal lines 462, 464,
466 and 468.
[0077]
The R pixel 220 is a pixel which has two light
20 reception elements which have color filters which allow
transmission of red light, and has two light reception
elements 410, the amplifier 443 and the ED 452.
[0078]
In addition, the light reception elements 410 and
25 the amplifier 443 are the same as illustrated in Fig.
5(a), and therefore will not be described.
[0079]
The ED 452 detects an electric charge of the light
reception elements, converts the electric charges
30 detected by the two connected light reception elements
410 into voltages and supplies the voltage to the
amplifier 443. While the ED 442 i l l u s t r a t e d i n Fig. 5 ( a )
d e t e c t s the e l e c t r i c charge detected by one l i g h t
reception element 410, t h i s ED 452 d e t e c t s the e l e c t r i c
charges detected by the two l i g h t reception elements 410.
5 [0080]
In addition, the G p i x e l 230 is the same as the R
pixel 220 except t h a t a color f i l t e r which allows
transmission of green l i g h t is provided instead of the
color f i l t e r which allows transmission of red l i g h t , and
10 therefore w i l l not be described.
[0081]
Further, the phase d i f f e r e n c e d e t e c t i o n p i x e l (Dla)
253 and the phase d i f f e r e n c e d e t e c t i o n pixel (Dlb) 254
a r e t h e same as the R p i x e l 220 except t h a t t h e r e is not
15 a color f i l t e r and the l i g h t block u n i t ( f o r example,
p a r t of a wiring) blocks l i g h t with respect t o half of
the l i g h t reception elements, and therefore w i l l not be
described.
100821
20 The signal l i n e s 462, 464, 466 and 468 read s i g n a l s
generated by each pixel connected t o these signal l i n e s .
The number of signal l i n e s indicated i n Fig. 5(b) is half
compared t o the number of signal l i n e s i l l u s t r a t e d i n Fig
5 ( a ) . In addition, the signal l i n e s 462, 464, 466 and
25 468 are the same a s i l l u s t r a t e d i n Fig. 5 ( a ) except t h a t
the number of signal l i n e s is small and each connected
pixel is d i f f e r e n t , and therefore w i l l not be described.
[0083]
Thus, the second image sensor 200 according t o the
30 f i r s t embodiment of the p r e s e n t invention is formed with
pixels (image generation p i x e l s and phase difference
detection pixels) which each have the two light reception
elements 410, the ED 442 and the amplifier 443.
[0084]
[Example of Pupil Division Performed by Four Types
5 of Phase Difference Detecting Pixels]
Figs. 6 and 7 are schematic views illustrating
pupil division of four types of phase difference
detecting pixels (Dl to D4) according to the first
embodiment of the present invention. In addition,
10 although the second image sensor 200 is arranged above
the pellicle mirror 160 as'illustrated in Fig. 2, the
second image sensor 200 will be described as an image
sensor parallel to an exit pupil with reference to Figs.
6 and 7 for ease of description.
15 [0085]
Fig. 6 is a schematic view illustrating pupil
division of the phase difference detecting pixel Dl and
the phase difference detecting pixel D2 according to the
first embodiment of the present invention.
20 [0086]
Fig. 6(a) schematically illustrates a relationship
between pupil division performed by the phase difference
detection pixel (phase difference detection pixel Dl)
corresponding to the exit pupil at a position dl and exit
25 pupils at the positions dl to d4. Fig. 6(a) illustrates
four exit pupils (exit pupils El to E4) at different
distances from the second image sensor 200, and the
second image sensor 200. Further, in the exit pupils El
to E4, center points (centers C1 to C4) indicating the
30 centers of the respective exit pupils are indicated.
[0087]
Furthermore, in the second image sensor 200, four
positions (El to F4) are indicated as positions of phase
difference detection pixels in the second image sensor
200. The position F1 and the position F4 have the same
5 distance (image height) from the center of the second
image sensor 200, and indicates positions from the center
which are opposite from each other. Further, the
position F2 and the position F3 also have the same image
heights and indicate positions from the center which are
10 opposite from each other. In addition, the up and down
directions of the second image sensor 200 illustrated in
Fig. 6(a) are the up and down directions (y axis
direction) of the area 210 of the second image sensor 200
illustrated in Fig. 3.
15 [0088]
Further, Fig. 6(a) illustrate pupil division lines
L21 to L24 as axes indicating boundaries between areas
divided by the phase difference detection pixel Dl at the
positions F1 to F4. In addition, Fig. 6(a) will be
20 described assuming that the phase difference detection
pixels Dl at the positions F1 to F4 are the phase
difference detection pixels (Dlc) 253 on the upper side
(an upper direction in Fig. 6(a)) of the light reception
of which is covered by the light block unit.
25 [0089]
Hereinafter, pupil-division by the phase difference
detection pixel (Dlc) 253 at the position F1 will be
described.
[0090]
30 In the phase difference detection pixel (Dlc) 253,
a light block unit is formed to perform pupil division of
dividing the exit pupil El into two. By this means, the
phase difference detection pixel (Dlc) 253) at the
position El receives subject light from the upper side of
this pupil division line L21 based on the boundary of the
5 pupil division line L21. In addition, as a method of
disposing the light block unit matching the position of
this exit pupil El, for example, a method (see, for
example, Japanese Patent Application Laid-Open No. 2009-
204987) of varying an arrangement of the light block unit
10 between pixels can be used.
[0091]
The phase difference detection pixel (Dlc) 253 at
the position F1 performs pupil division with respect to
the exit pupil El to divide the exit pupil El by forming
15 the light block unit to meet the position of the exit
pupil El. However, the pupil division line L21 is
diagonal to the optical axis (a dotted line L29 in Fig.
6), and therefore it is not possible to perform pupil
division with respect to the exit pupils at the other
20 positions to divide the exit pupil into two. For example,
as to the exit pupil E2, the phase difference detection
pixel (Dlc) 253 at the position F1 receives subject light
passing through an area which is three-fourths from the
top of the exit pupil E2. Further, as to the exit pupil
25 E3, subject light passing the area which is 90% from the
top of the exit pupil E3 is received. Furthermore, as to
the exit pupil E4, the entire subject light passing the
exit pupil E4 is received.
[0092]
3 0 Thus, the phase difference detection image (Dlc)
253 at the position F1 can perform pupil division of
dividing the exit pupil El at the position dl into two,
and can precisely detect the phase difference for the
exit pupil El. However, subject light is not divided
into two for the exit pupils E2 to E4, and precision to
5 detect the phase difference deteriorates.
[0093]
In addition, although, similar to the position El,
in the phase difference detection pixels (Dlc) 253 at the
position F2 and the position F4, light block units are
10 formed to meet the position of the exit pupil El and the
phase difference can be precisely detected for the exit
pupil El, precision deteriorates for the exit pupils E2
to E4.
[0094]
15 Thus, although the phase detection pixel Dlc
precisely detects the phase difference for the exit pupil
El, precision for the exit pupils E2 to E4 deteriorates.
[0095]
Fig. 6(b) schematically illustrates a relationship
20 between pupil division performed by the phase difference
detection pixel (phase difference detection pixel D2)
corresponding to the exit pupils at the position d2 and
an exit pupil at the positions dl to d4. Similar to Fig.
6(a), Fig. 6(b) illustrates the exit pupils (exit pupils
25 El to E4) and the second image sensor 200.
[0096]
Instead of the exit pupil lines L21 to L24
illustrated in Fig. 6(a), Fig. 6(b) illustrates exit
pupil lines L31 to L34 as axes indicating boundaries
30 between areas at which the phase difference detection
pixels D2 at the positions F1 to F4 are divided.
[0097]
In the phase difference detection pixel D2, a light
block unit is formed to be capable of performing pupil
division of dividing the exit pupil E2 into two. That is,
5 although, as illustrated in Fig. 6(b), the phase
difference detection pixel D2 can precisely detect the
phase difference for the exit pupil E2, precision for the
exit pupils El, E3 and E4 deteriorates.
[0098]
10 Fig. 7 is a schematic view illustrating pupil
division of the phase difference detecting pixel D3 and
the phase difference detecting pixel D4 according to the
first embodiment of the present invention.
[0099]
15 Fig. 7(a) schematically illustrates a relationship
between pupil division performed by the phase difference
detection pixel (phase difference detection pixel D3)
corresponding to the exit pupil at the position d3 and
exit pupils at the positions dl to d4. Similar to Fig.
20 6(a), Fig. 7(a) illustrates the exit pupils (exit pupils
El to E4) and the second image sensor 200.
[ OlOO]
Instead of the exit pupil lines L21 to L24
illustrated in Fig. 6(a), Fig. 7(a) illustrates exit
25 pupil lines L41 to L44 as axes indicating boundaries
between areas at which the phase difference detection
pixels D3 at the positions F1 to F4 are divided.
[OlOl]
In the phase difference detection pixel D3, a light
30 block unit is formed to be capable of performing pupil
division of dividing the exit pupil E3 into two. That is,
although, a s i l l u s t r a t e d i n Fig. 7 ( a ) , the phase
difference detection pixel D3 can precisely detect the
phase difference for the e x i t pupil E3, precision for the
e x i t pupils E l , E2 and E4 d e t e r i o r a t e s .
5 [0102]
Fig. 7(b) schematically i l l u s t r a t e s a relationship
between pupil division performed by the phase difference
detection pixel (phase difference detection pixel D4)
corresponding t o the e x i t pupil a t t h e p o s i t i o n d4 and
10 e x i t pupils a t the positions dl t o d4. Similar t o Fig.
6 ( a ) , Fig. 7 (b) i l l u s t r a t e s the e x i t pupils ( e x i t pupils
E l t o E4) and the second image sensor 200.
[0103]
Instead of the e x i t pupil l i n e s L21 t o L24
15 i l l u s t r a t e d i n Fig. 6 ( a ) , Fig. 7(b) i l l u s t r a t e s e x i t
pupil l i n e s L51 t o L54 as axes indicating boundaries
between areas a t which the phase difference detection
pixels D4 a t t h e positions F1 t o F4 are divided.
[0104]
20 In the phase difference detection pixel D4, a l i g h t
block unit is formed t o be capable of performing pupil
division of dividing the e x i t pupil E4 i n t o two. That is,
although, a s i l l u s t r a t e d i n Fig. 7 ( b ) , the phase
difference detection pixel D4 can p r e c i s e l y d e t e c t the
25 phase difference f o r the e x i t pupil E4, precision for the
e x i t pupils E l t o E3 d e t e r i o r a t e s .
[0105]
Thus, i n the phase difference detection pixels D l
t o D4, l i g h t block units are formed t o meet the e x i t
30 pupils a t d i f f e r e n t positions. Thus, by providing i n the
second image sensor 200 the phase difference detection
pixels meeting exit pupils at different positions, when
the imaging device 100 is a single-lens reflex camera in
which a lens unit can be exchanged, it is also possible
to support an exchange lens in which exit pupils are at
5 different positions.
[0106]
In addition, although the phase difference
detection pixels Dl to D4 meeting the positions of the
four exit pupils have been assumed, the phase difference
10 detection pixels are by no means limited to this. As
long as rows of phase difference detection pixels and
rows of image generation pixels are alternately arranged
(a rate of phase difference detection pixels neighbor to
image generation pixels is fixed), the number may be
15 other than four. When, for example, the second image
sensor 200 is provided to a lens integrated camera, only
a phase difference detection pixel may be arranged with
respect to the position of one exit pupil.
[0107]
20 [Example of Pixel neighbor to Image Generation
Pixel]
Fig. 8 is a schematic view illustrating pixels
neighbor to image generating pixels of the second image
sensor 200 according to the first embodiment of the
25 present invention and pixels neighbor to image generating
pixels of the conventional image sensor. In addition, an
example of an influence of (a light reception element of)
a phase difference detection pixel neighbor to (a light
reception element of) an image generation pixel will be
30 described with reference to Fig. 8 assuming that light of
a low wavelength leaks. That is, it is assumed that the
amount of leakage of low wavelength light varies and
therefore a wavelength property of light received by a
light reception element of the image generation pixel has
slightly changed
5 [0108]
Fig. 8(a) illustrates an area (six rows and ten
columns) in which image generation pixels and phase
difference detection pixels in the conventional image
sensor to which both of the image generation pixels and
10 the phase difference detection pixels are provided are
arranged. Fig. 8(a) illustrates an area in which eight
phase difference detection pixels are arranged in one row
which is the third row from the top, and the other pixels
are all image generation pixels.
15 [0109]
As illustrated in Fig. 8(a), in the conventional
image sensor to which both of the image generation pixels
and the phase detection pixels are provided, phase
difference detection pixels are partially arranged.
20 Hence, only the image generation pixels around the
partially arranged phase difference detection pixels are
image generation pixels neighbor to the phase difference
detection pixels.
[ OllO]
25 Hereinafter, three G pixels (G pixels 511 to 513)
of different neighboring pixels among pixels in the area
illustrated in Fig. 8(a) will be focused upon, and
described with reference to Fig. 8 (b) .
[Olll]
3 0 In Fig. 8(b), the G pixels 511 to 513 illustrated
in Fig. 8(a) are indicated together with arrows
indicating lights leaking from the phase detection pixels.
[0112]
The G pixel 511 is the G pixel in which eight
neighboring pixels are all image generation pixels. This
5 G pixel 511 does not include a phase difference detection
pixel in a neighboring pixel, and therefore has the same
property as pixels of an image sensor which do not have
phase difference detection pixels. .
[0113]
10 The G pixel 512 is the G pixel in which seven of
the eight neighboring pixels are image generation pixels,
and one is the phase difference detection pixel. This G
pixel 512 is neighbor to one phase difference detection
pixel, and therefore is influenced by this phase
15 difference detection pixel. When, for example, the phase
difference detection pixel does not have a color filter,
light of a short wavelength leaks to the G pixel 512 from
the neighboring phase difference detection pixel. This
causes that the wavelength property of light received by
20 the light reception element of the G pixel 512 is
slightly different from the wavelength property of the G
pixel 511.
[0114]
The G pixel 513 is the G pixel in which five of the
25 eight neighboring pixels are image generation pixels, and
three are the phase difference detection pixels. This G
pixel 513 is neighbor to the three phase difference
detection pixels, and therefore is influenced by these
three phase difference detection pixels. That is, the
30 amount of leaking light increases compared to the G pixel
512. Therefore, the wavelength property of light
received by the light reception element of the G pixel
513 differs from the wavelength property of the G pixel
511 and the wavelength property of the G pixel 512.
[0115]
5 Thus, in the conventional image sensor to which
both of the image generation pixels and the phase
difference detection pixels are provided, there are image
generation pixels which are neighbor to the phase
difference detection pixels and image generation pixels
10 which are not neighbor to the phase difference detection
pixels. Hence, a problem occurs that the wavelength
property of light received by the light reception
elements of the image generation pixels varies.
[0116]
15 Fig. 8(c) illustrates an area in which a row in
which G pixels and B pixels in the second image sensor
200 according to the first embodiment of the present
invention are arranged as image generation pixels, and
rows in which phase difference detection pixels which are
20 vertically neighbor to this row are arranged. Fig. 8(c)
will be described assuming that light reception elements
of three rows and eight columns (three x four pixels) in
the second row and the fourth row from the top of the
area 210 in Fig. 3.
25 [0117]
As illustrated in Fig. 8(c), in the second image
sensor 200, rows (upper and lower rows) of the row of the
image generation pixels are rows in which phase
difference detection pixels are arranged. Hence, all
30 image generation pixels are image generation pixels
neighbor to the phase difference detection pixels.
[0118]
Meanwhile, a neighboring phase difference detection
pixel will be described with reference to Fig. 8(d) by
focusing upon one light reception element (light
5 reception element 521) in the G pixel 230.
[0119]
In Fig. 8(d), the light reception element 521
illustrated in Fig. 8(c) is indicated together with
arrows indicating lights leaking from the phase detection
10 pixels.
[0120]
As to the light reception element 521, two of the
neighboring eight light reception elements are light
reception elements, and six are light reception elements
15 of the phase difference detection pixels. This light
reception element 521 is neighbor to the six light
reception elements of the phase difference detection
pixels, and therefore is influenced by the six light
reception elements of the phase difference detection
20 pixels. In addition, rows of the phase difference
detection pixels and rows of image generation pixels are
alternately arranged in the second image sensor 200, and
therefore all image generation pixels except ends of the
rows are neighbor to the six light reception elements of
25 the phase difference detection pixels (a rate of phase
difference detection pixels and image generation pixels
of neighboring pixels is fixed).
[0121]
As illustrated in Fig. 8(d), in the second image
30 sensor 200, light reception elements of all image
generation pixels except pixels at the ends of the second
image sensor 200 are influenced by the six light
reception elements of the phase difference detection
pixels, and therefore the wavelength property of light
received by the light reception elements of the image
5 generation pixels becomes uniform. That is, the pixels
at the ends of the second image sensor 200 are not used
(removed from effective pixels), so that it is not
necessary to correct the wavelength property of light
received by the light reception elements.
10 [0122]
Thus, the rate of light reception elements of the
phase difference detection pixels and light reception
elements of the image generation pixels are made uniform
for light reception elements neighbor to light reception
15 elements of the image generation pixels in an area of
effective pixels, so that it is possible to make the
property of the light reception elements of the image
generation pixels uniform. In addition, although a case
has been described with the first embodiment of the
20 present invention where the image generation pixel has
two light reception elements, the image generation pixel
is not limited to this, and it is possible to obtain the
same effect even when an image generation pixel has one
light reception element. That is, the rate of phase
25 difference detection pixels and image generation pixels
is fixed for each pixel neighbor to the image generation
pixels in an area of effective pixels (pixels which
receive subject light and generate an image), so that it
is possible to make the property of light reception
30 elements of the image generation pixels uniform.
[0123]
[Example of Image generated by Second Image Sensor]
Fig. 9 is a schematic view illustrating a captured
image generated based on a signal of the second image
sensor 200 according to the first embodiment of the
5 present invention and a captured image generated based on
a signal of the conventional image sensor. In addition,
in Fig. 9, a captured image to be generated is an image
having the maximum number of pixels which can be
generated by each image sensor.
10 [0124]
Fig. 9(a) illustrates a captured (captured image
550) which is generated based on signals outputted from
the conventional image sensor (image sensor 540) to which
image generation pixels and the phase difference
15 detection pixels are provided and an image sensor 540.
[0125]
In the image sensor 540, phase difference detection
pixels are arranged in part of four rows, and sites at
which these phase difference detection pixels are
20 arranged are schematically illustrated by broken lines
(phase difference detection pixel position 541). Further,
the magnitude (the number of light reception elements
(pixels) in the horizontal direction (reading direction)
of the image sensor 540 is W1, and the magnitude (the
25 number of light reception elements (pixels) in the
vertical direction (a direction orthogonal to the reading
direction) is HI.
[0126]
In the captured image 550, sites of image data
30 including positions of the phase difference detection
pixels are schematically indicated by broken lines (data
direction of the image sensor 540, and the number of
pixels (H2) in the vertical direction is also the same as
the number of light reception elements (pixels) (Hl) in
the vertical direction of the image sensor 540. When,
5 for example, the number of effective light reception
elements (the number of light reception elements used to
generate a captured image) of the image sensor 540 is
4592 columns and 3056 rows, the captured image 550 having
the number of pixels 4592 columns x3056 rows is generated.
10 [0130]
Fig. 9(b) illustrates the second image sensor 200
according to the first embodiment of the present
invention and a captured image (captured image 560)
generated from a signal outputted from this second image
15 sensor 200.
[0131]
In the second image sensor 200, rows of phase
difference detection pixels and rows of captured images
are alternately arranged, and the rows of these phase
20 difference detection pixels are schematically illustrated
by a plurality of broken lines. Further, the magnitude
(the number of light reception elements) in the
horizontal direction (reading direction) of the second
image sensor 200 is W11, and the magnitude (the number of
25 light reception elements) in the vertical direction is
H11. Furthermore, in the captured image 560, the
magnitude (the number of pixels) in the horizontal
direction (reading direction) of the captured image 560
is W12, and the magnitude (the number of pixels) in the
30 vertical direction is H12.
[0132]
Hereinafter, generation of the captured image 560
by the second image sensor 200 will be described.
[0133]
In the second image sensor 200, rows of phase
5 difference detection pixels and rows of image generation
pixels are alternately arranged, and, when a captured
image is generated, the captured image is generated using
only data of the rows of the image generation pixels.
Further, half of the pixels are phase difference
10 detection pixels, and therefore, when a captured image is
generated, image data at positions of the phase
difference detection pixels are not supplemented, By
this means, the maximum number of pixels in the vertical
direction of the captured image generated from the signal
15 of the second image sensor 200 is half the number of
light reception elements in the vertical direction of the
image sensor 540 (the number of pixels is also half).
Further, the second image sensor 200 has two light
reception elements in one image generation pixel, the
20 number of maximum pixels in the horizontal direction of
the captured image generated from the signal of the
second image sensor 200 is half the number of light
reception elements in the horizontal direction in the
image sensor 540 (the number of pixels is equal).
25 [0134]
That is, as illustrated in Fig. 9(b), the captured
image 560 generated from the signal of the second image
sensor 200 is an image which does not include data
obtained by supplementing data at the positions of the
30 phase difference detection pixels, and which is formed
only with data generated by the image capture element.
Further, in the captured image 560, the number of pixels
(W12) in the horizontal direction is half the number of
light reception elements (W11) in the horizontal
direction of the second image sensor 200, and the number
5 of pixels (H12) in the vertical direction is half the
number of light reception elements (H11) in the vertical
direction of the second image sensor 200. When, for
example, the number of effective light reception elements
of the second image sensor 200 is 4592 columns and 3056
10 rows, the captured image 560 having the number of pixels
of 2296 columns and 1528 rows is generated.
[0135]
Thus, in the second image sensor 200, even though
rows of phase difference detection pixels and rows of
15 image generation pixels are alternately arranged, an
aspect ratio of an image to be generated can be made the
same as in the image sensor to which only image
generation pixels are provided. That is, aspect ratios
of an image (live view image) generated from the signal
20 of the second image sensor 200) and an image (still
image) generated from the signal of the first image
sensor 140 can be made the same. By this means, it is
possible to easily generate a live view image of a still
image from the signal from the second image sensor 200
25 (without performing special correction processing).
[0136]
In addition, although a case has been described
with the first embodiment of the present invention where
phase difference detection pixels which each have two
30 light reception elements and image generation pixels
which each have two light reception elements are used,
the present invention is by no means limited to this.
Even when image generation pixels which each have one
light reception element are used, by generating an image
using two pixels which have the identical color filters
5 and which continue in the reading direction as a pair of
pixels (a pixel unit of an image to be generated), it is
possible to make the aspect ratios the same.
[0137]
[Example of Data Reading Speed of Second Image
10 Sensor]
Fig. 10 is a graph illustrating an example of a
data reading speed of the second image sensor 200
according to the first embodiment of the present
invention and an example of a data reading speed of the
15 conventional image sensor. Further, Fig. 10 illustrates
a data reading speed when each image sensor generates a
captured image having the maximum number of pixels.
[0138]
In addition, similar to Fig. 9, Fig. 10 assumes
20 that each image sensor has light reception elements of
4592 columns and 3056 rows. That is, the second image
sensor 200 according to the first embodiment of the
present invention has pixels of 2296 columns and 3056
rows, and the conventional image sensor has pixels of
25 4592 columns and 3056 rows. Further, most are image
generation pixels in the conventional image sensor and a
reading time does not become short even if reading of one
to three rows is skipped, and it is assumed that data is
read from all phase difference detection pixels for ease
30 of description.
[0139]
Fig. 10(a) illustrates a time required to read data
of all pixels arranged in one row (a data reading time
related to the reading direction) in a graph in which the
horizontal axis is an axis indicating a data reading time.
5 Fig. 10(a) illustrates a data reading time (time TI) of
the conventional image sensor and a data reading time
(time T2) of the second image sensor 200 according to the
first embodiment of the present invention as data reading
times.
10 [0140]
Hereinafter, a difference between the time T1 and
the time T2 will be described. The conventional image
sensor has one light reception element in one image
generation pixel, and reads data from pixels 4592 times
15 per row. That is, the time T1 refers to the time related
to 4592 times of reading of data.
[0141]
Meanwhile, the second image sensor 200 has two
light reception elements in one image generation pixel,
20 and data is read from pixels 2296 times per row. That is,
the time T2 refers to the time related to 2296 times of
reading of data.
[0142]
As illustrated in Fig. 10(a), the second image
25 sensor 200 according to the first embodiment of the
present invention has two light reception elements in one
image generation pixels, and has a faster data reading
speed per row than the conventional image sensor.
[0143]
3 0 Fig. 10(b) illustrates a time required to read data
of all pixels in the orthogonal direction orthogonal to
the reading d i r e c t i o n (a data reading t i m e r e l a t e d t o the
orthogonal d i r e c t i o n orthogonal t o the reading d i r e c t i o n )
i n the graph i n which the horizontal axis is an axis
indicating a data reading time. Fig. 10(b) i l l u s t r a t e s a
5 time (time T3) i n the conventional image sensor and a
time (time T4) of the second image sensor 200 when a
phase difference is detected using phase difference
detection pixels i n one row (when pupil d i v i s i o n is
performed i n the reading d i r e c t i o n ) . Further, Fig. 10(b)
10 i l l u s t r a t e s a data reading time (time T5) of the second
image sensor 200 when a phase difference is detected
using phase d i f f e r e n c e d e t e c t i o n pixels i n a p l u r a l i t y of
rows (pupil division is performed i n a d i r e c t i o n
orthogonal t o the reading d i r e c t i o n ) .
15 [0144]
Hereinafter, a difference between the time T3, the
t i m e T4 and the t i m e T5 w i l l be described. Most of
pixels are image generation pixels i n the conventional
image sensor and there are also image generation pixels
20 i n rows i n which phase d i f f e r e n c e d e t e c t i o n pixels are
provided, so t h a t there are few rows from which data of
pixels cannot be read. That is, i n the conventional
image sensor, rows t o read are s p e c i f i e d (specified i n
the y axis d i r e c t i o n ) 3056 times. That is, the time T3
25 r e f e r s t o a time r e l a t e d t o 3056 times of reading of data.
[0145]
Meanwhile, rows of image generation pixels and rows
of phase d i f f e r e n c e d e t e c t i o n pixels are a l t e r n a t e l y
arranged i n the second image sensor 200, and the number
30 of times of specifying rows t o read which is required t o
generate a captured image is 1528 times (which is half
3056 rows). When pupil division in the horizontal
direction is performed for rows of phase difference
detection pixels, pupil division can be performed using
data of phase difference detection pixels in at least one
5 row. Further, when pupil division in the vertical
direction is performed, pupil division can be performed
using data of pixels arranged in columns of two pixels
arranged in a pair of pixels among pixels in rows which
are pupil-divided in the vertical direction. The time T4
10 refers to a time related to 1528 times + 1 time of data
reading upon pupil division in the horizontal direction,
and the time T5 refers to a time related to 1528 times +
764 times of data reading upon pupil division in the
vertical direction.
15 [0146]
As illustrated in Fig. 10 (b), rows in which only
image generation pixels are arranged and rows in which
only phase difference detection pixels are arranged are
alternately arranged in the second image sensor 200
20 according to the first embodiment of the present
invention, so that the number of rows which are not read
increases compared to the conventional image sensor. By
this means, the data reading speed becomes fast compared
to the conventional image sensor.
25 [0147]
Fig. 10(c) illustrates a time required to read data
of pixels when one captured image is generated (a reading
time related to the entire image sensor) in a graph in
which the horizontal axis is an axis indicating a data
30 reading time. Fig. 10(c) illustrates a data reading time
(time T6) in the conventional image sensor and a data
reading time (time T7) of the second image sensor 200
when a phase difference is detected using phase
difference detection pixels in one row as data reading
times. Further, Fig. 10(c) i l l u s t r a t e s a data reading
5 time (time T8) i n the second image sensor 200 when a
phase difference is detected using phase difference
detection pixels i n 764 rows.
[0148]
Hereinafter, a difference between the time T6, the
10 time T7 and the time T8 w i l l be described. In the
conventional image sensor, rows t o read is specified
(specified in the y a x i s d i r e c t i o n ) 3056 times, and data
is read from pixels of each specified row 4592 times.
That is, data is read from pixels 3056 x 4592 times. The
15 time T6 refers t o the time related t o 3056 x 4592 times
of data reading.
[0149]
Meanwhile, when a phase difference is detected
using phase difference detection pixels i n one row, the
20 second image sensor 200 specifies the rows to read 1528 +
1 times and read data from pixels of each specified data
2296 times. That is, data is read from pixels (1528 + 1)
x 2296 times. The time T7 refers t o the time related t o
(1528 + 1) x 2296 times of data reading.
25 [0150]
Further, when a phase difference is detected in the
v e r t i c a l d i r e c t i o n , t h e rows t o read are specified 1528 +
764 times and data is read from pixels of each specified
row 2296 times (for ease of description, data is read
30 from a l l pixels in rows of phase difference detection
p i x e l s ) . That is, data is read from pixels (1528 + 764)
x 2296 times. The time T8 refers to the time related to
(1528 + 764) x 2296 times of data reading.
[0151]
As illustrated in Fig. 10(c), the second image
5 sensor 200 according to the first embodiment of the
present invention has a faster data reading speed per row
than the conventional image sensor.
[0152]
Thus, with the first embodiment of the present
10 invention, by fixing the rate of phase difference
detection pixels neighbor to image generation pixels
(light reception elements), it is possible to make the
property of the image generation pixels uniform. By this
means, it is possible to reduce correction processing
15 related to the property of each pixel upon generation of
a captured image.
[0153]
Further, with the first embodiment of the present
invention, in rows of image generation pixels, image
20 generation pixels are arranged in Bayer alignment using
two light reception elements which have filters of the
identical property as one pair. By this means, it is
possible to generate a captured image using the same
processing as processing in conventional Bayer alignment,
25 and reduce correction processing related to colors upon
generation of the captured image.
[0154]
Further, with the first embodiment of the present
invention, one pixel has two light reception elements in
30 the image generation pixels and the phase difference
detection pixels. By this means, it is possible to
shorten the time required to read data from pixels in the
reading direction. Further, an area of a light reception
plane in one pixel is widened, so that it is possible to
make a signal generated by one pixel intense.
5 Furthermore, it is possible to generate a captured image
having the same aspect ratio as the image sensor to which
only image generation pixels are provided.
101551
<2. Modified Example>
10 A case has been described with the first embodiment
of the present invention where phase difference detection
pixels to be pupil-divided in the reading direction and
phase difference detection pixels to be pupil-divided in
a direction orthogonal to the reading direction are
15 alternately arranged per line in the second image sensor
200. Meanwhile, phase difference detection pixels and
image generation pixels may be provided in other
arrangements. For example, rows of phase difference
detection pixels and rows of image generation pixels can
20 be alternately arranged such that the number of phase
difference detection pixels neighbor to image generation
pixels are uniform (the rate is fixed) in all image
generation pixels. Thus, the arrangements of the phase
difference detection pixels may include various patterns
25 in addition to that described in the first embodiment.
[0156]
Hence, an example of an image sensor which is
opposite to a second image sensor according to a first
embodiment where positions of phase difference detection
30 pixels which forms a pair are different will be described
with reference to Fig. 11 as an example of various
patterns. Further, an example of an image sensor in
which phase difference detection pixels are only pixels
to be pupil-divided in the reading direction will be
described with reference to Figs. 12 and 13. Furthermore,
5 an example of an image sensor in which rows of phase
difference detection pixels and rows of image generation
pixels are alternately arranged every two other rows will
be described with reference to Fig. 14.
[0157]
10 [Example of Arrangement of Pixels of Second Image
Sensor]
Figs. 11 to 14 are schematic views illustrating
arrangements of light reception elements of the second
image sensor according to a modified example of the first
15 embodiment of the present invention. For ease of
description, Figs. 11 to 14 will be described using an
area of part of light reception elements (light reception
elements of sixteen rows and sixteen columns) of light
reception elements of each pixel forming the second image
20 sensor 200. In addition, subsequent to Figs. 11 to 14, a
difference from an area 210 according to the first
embodiment of the present invention illustrated in Fig. 3
will be focused upon and described.
[0158]
25 Fig. 11 is a view illustrating an example of an
arrangement of light reception elements of a second image
sensor in which positions of a pair of phase difference
detecting pixels which form a pair are opposite to those
of the first embodiment according to a modified example
30 of the first embodiment of the present invention.
[0159]
Fig. 11 illustrates an area 710 which is an area of
light reception elements of 16 rows and 16 columns in the
second image sensor in which the positions of the phase
difference detection pixels which form a pair are
5 opposite to those in the first embodiment, and which is
an area corresponding to the area 210 illustrated in Fig.
3. Fig. 11 illustrates horizontal Dl row 721, horizontal
D2, row 723, horizontal D3 row 725 and horizontal D4 row
727 as rows in which light reception elements to be
10 pupil-divided in the reading direction are arranged.
Further, a vertical detection row 722, a vertical
detection row 724, a vertical detection row 726 and a
vertical detection row 728 are illustrated as rows in
which light reception elements to be pupil-divided in the
15 vertical direction are arranged. The positions of light
reception elements which form pairs in these rows are
opposite compared to the rows in which light reception
elements to be pupil-divided in the area 210 illustrated
in Fig. 3 are arranged. For example, upon comparison
20 between horizontal Dl row 721 and horizontal Dl row 321
(see Fig. 3), the positions of the phase difference
detection pixel Dla and the phase difference detection
pixel Dlb are opposite. In addition, similar to the rows
in which light reception elements to be pupil-divided in
25 the reading direction are arranged, the positions of the
light reception elements which form pairs are opposite
even in rows in which light reception elements to be
pupil-divided in a direction orthogonal to the reading
direction.
30 [0160]
Thus, even when positions of phase difference
detection pixels which form pairs are different from
those of the first embodiment of the present invention,
it is possible to fix the rate of phase difference
detection pixels neighbor to the image generation pixels
5 similar to the first embodiment of the present invention.
[0161]
Fig. 12 is a view illustrating an arrangement of
light reception elements of the second image sensor in
which only phase difference detection pixels to be pupil-
10 divided in the reading direction are arranged in a row of
the phase difference detection pixels according to the
modified example of the first embodiment of the present
invention.
[0162]
15 Fig. 12 illustrates an area 730 which is an area of
light reception elements of 16 rows and 16 columns in the
second image sensor in which only phase difference
detection pixels to be pupil-divided in the reading
direction are arranged in the rows of the phase
20 difference detection pixels, and which is an area
corresponding to the area 210 illustrated in Fig. 3. Fig
12 illustrates horizontal Dl row 731, horizontal D2 row
732, horizontal D3 row 733, horizontal D4 row 734,
horizontal D5 row 735, horizontal D6 row 736, horizontal
25 D7 row 737 and horizontal D8 row 738 as rows in which
light reception elements to be pupil-divided in the
reading direction are arranged. Horizontal D5 row 735 to
horizontal D8 row 738 are rows in which phase difference
detection pixels meeting positions of exit pupils
30 different from horizontal Dl row 731 to horizontal D4 row
734. Further, in rows of phase difference detection
pixels in the area 730, phase difference detection pixels
which form pairs are arranged.
[0163]
Thus, by arranging only phase difference pixels to
5 be pupil-divided in the reading direction such that phase
difference detection pixels which form pairs are arranged,
it is possible to support more positions of exit pupils
than the second image sensor 200 according to the first
embodiment.
10 [0164]
Fig. 13 is view illustrating an example of an
arrangement of the second image sensor which is different
from Fig. 12 and in which only phase difference detecting
pixels to be pupil-divided in the reading direction are
15 arranged in a row of the phase difference detecting
pixels according to the modified example of the first
embodiment of the present invention.
[0165]
Fig. 13 illustrates an area 740 which is an area of
20 light reception elements of 16 rows and 16 columns in the
second image sensor in which only phase difference
detection pixels to be pupil-divided in the reading
direction are arranged in the rows of the phase
difference detection pixels, and which has a different
25 pattern from the area 730 illustrated in Fig. 12. Fig.
13 illustrates horizontal Dla row 741, horizontal Dlb row
742, horizontal D2a row 743, horizontal D2b row 744,
horizontal D3a row 745, horizontal D3b row 746,
horizontal D4a row 747 and horizontal D4b row 748 as rows
30 in which light reception elements to be pupil-divided in
the reading direction are arranged. Horizontal Dla row
741 is a row i n which only phase difference detection
pixels Dla are arranged and horizontal Dlb row 742 is a
row in which only the phase difference detection pixels
Dlb are arranged. Similarly, horizontal D2a row 743 t o
5 horizontal D4b row 748 are rows i n which only phase
difference detection image D2a t o D4b are arranged.
[0166]
By t h i s means, by arranging only phase difference
detection pixels t o be pupil-divided in the reading
10 direction such that the phase difference detection pixels
which form pairs are provided i n separate rows, it is
possible t o narrow a pitch between phase difference
detection pixels which receive l i g h t pupil-divided in the
i d e n t i c a l d i r e c t i o n and improve precision t o d e t e c t t h e
15 phase difference.
[0167]
In addition, there are cases where only phase
difference detection pixels t o be pupil-divided in the
reading d i r e c t i o n a s i l l u s t r a t e d i n Figs. 12 and 13 are
20 arranged i n rows of phase difference detection pixels and,
in addition, there are cases where only phase difference
detection pixels t o be pupil-divided in a direction
orthogonal to the reading direction are arranged in rows
of phase difference detection pixels.
25 [0168]
Fig. 14 is a view i l l u s t r a t i n g an example of an
arrangement of l i g h t reception elements of the second
image sensor i n which a row of phase difference detecting
pixels and a row of image generating pixels are
30 a l t e r n a t e l y arranged every two other rows.
[0169]
Fig. 14 illustrates an area 750 which is an area of
light reception elements of 16 rows and 16 columns in the
second image sensor in which rows of phase difference
detection pixels and rows of image generation pixels are
5 alternately arranged every two other rows, and which is
an area corresponding to the area 210 illustrated in Fig.
3. Fig. 14 illustrates that two rows in which image
generation pixels are arranged and two rows in which
phase difference detection pixels are arranged are
10 alternately arranged. In case of this arrangement, light
reception elements of image generation pixels are
neighbor to light reception elements of three phase
difference detection pixels. That is, even when rows of
image generation pixels and rows of phase difference
15 detection pixels are alternately arranged as described in
the first embodiment, it is possible to fix a rate of
phase difference detection pixels neighbor to image
generation pixels.
[0170]
20 In addition, even when rows of image generation
pixels are arranged every two other rows or rows of phase
difference detection pixels are arranged every three
other row, it is possible to fix the rate of phase
difference detection pixels neighbor to image generation
25 pixels. In this case, by performing correction
processing such that the aspect ratio is the same as the
still image when a captured image is generated, it is
possible to generate a live view image of the still image
[0171]
3 0 As illustrated in Figs. 11 to 14, according to the
arrangement other than the arrangement in the first
embodiment of the present invention, it is possible to
fix the rate of phase difference detection pixels
neighbor to image generation pixels.
[0172]
5 In addition, although the first embodiment and the
modified example of the present invention have been
described where phase difference detection pixels and
image generation pixels each have two light reception
elements, the present invention is by no means limited to
10 this. When, for example, data is transferred fast to
such an extent that the number of pixels does not need to
be reduced to half, phase difference detection pixels and
image generation pixels which each have one light
reception element per pixel such that the rate of phase
15 difference detection pixels neighbor to image generation
pixels is fixed. Further, by creating a light reception
element of a rectangular shape (having the size
corresponding to two light reception elements according
to the first embodiment) when a second image is made, it
20 may be possible to form one pixel using one light
reception element.
[0173]
In addition, although the first embodiment and the
modified example of the present invention assume that the
25 second image sensor 200 is a CMOS sensor, the present
invention is by no means limited to this and a CCD
(Charge Coupled Device) sensor may be used in some cases.
Further, although using an image generated from a signal
of the second image sensor 200 is assumed as a live view
30 image, the present invention is by no means limited to
this, and, for example, movies may be stored in a memory
unit 181 in some cases.
[0174]
In addition, the embodiment of the present
invention is an exemplary embodiment for embodying the
5 present invention, the matters according to the
embodiment of the present invention and matters
specifying the inventions in the claims have
correspondences as clearly described in the embodiment of
the present invention. Similarly, the matters specifying
10 the inventions in the claims and the matters in the
embodiment of the present invention assigned the same
names as the matters specifying the inventions each have
correspondences. However, the present invention is by no
means limited to the embodiment, and can be embodied by
15 variously modifying the embodiment within a scope which
does not deviate from the spirit of the present invention.
[0175]
Further, processing process described in the
embodiment of the present invention may be understood as
20 a method including a series of these processes, a program
for causing a computer to execute a series of these
processes or a recording medium which records this
program. For this recording medium, for example, CDs
(Compact Disk) , MDs (Mini Disk) , DVDs (Digital Versatile
25 Disk), memory cards, Blu-ray Discs (registered trademark)
can be used.
REFERENCE SIGNS LIST
[0176]
30 100 Imaging device
110 Lens unit
Zoom lens
Diaphragm
Focus lens
Operation reception unit
Control unit
First image sensor
First signal processing unit
Pellicle mirror
Second signal processing unit
Memory unit
Display unit
Focus adjustment decision unit
Drive unit
Second image sensor

CLAIMS
1. An image capture element comprising:
a plurality of phase difference detection pixels
5 which generate signals for performing adjusted focus
decision by way of phase difference detection; and
a plurality of image generation pixels which
generate signals for generating an image,
wherein a first pixel group formed by arranging
10 part of phase difference detection pixels of the
plurality of phase difference detection pixels in a
specific direction and a second pixel group formed by
arranging part of image generation pixels of the
plurality of pixel generation pixels in the specific
15 direction are alternately arranged in an orthogonal
direction orthogonal to the specific direction.
2. The image capture element according to claim 1,
wherein each of the plurality of image generation pixels
20 has a fixed ratio of the phase difference detection
pixels and the image generation pixels for each
neighboring pixel in an area of the image capture element
which receives subject light.
25 3. The image capture element according to claim 1,
wherein
the first pixel group comprises a plurality of
phase difference detection pixels forming one or a
plurality of lines, and
3 0 the second pixel group comprises a plurality of
image generation pixels forming one or two lines.
4. The image capture element according to claim 1,
wherein the specific direction is a reading direction
when data generated by the phase difference detection
5 pixels and the image generation pixels is read from the
phase difference detection pixels and the image
generation pixels.
5. The image capture element according to claim 1,
10 wherein
the first pixel group comprises a plurality of
phase difference detection pixels forming one line,
the second pixel group comprises a plurality of
image generation pixels forming one line, and
15 two continuous image generation pixels of the
plurality of image generation pixels which comprise color
filters of an identical property and are arranged in the
specific direction form a pair of image generation pixels,
and each pixel is arranged using the pair of image
20 generation pixels as pixel units.
6. The image capture element according to claim 5,
wherein the plurality of image generation pixels is
arranged in Bayer alignment in the pixel units in the
25 image capture element.
7. The image capture element according to claim 1,
wherein two phase difference detection pixels of the
plurality of phase difference detection pixels which
30 perform pupil division in an identical direction and
receive lights divided in one way of the identical
direction form a pair of phase difference detection
pixels as two continuous phase difference detection
pixels arranged in the specific direction, and each pixel
is arranged using the pair of the phase difference
5 detection pixels as pixel units.
8. The image capture element according to claim 1,
wherein two continuous light reception elements of light
reception elements of the plurality of image generation
10 pixels which comprise color filters of an identical
property and which are arranged in the specific direction
form a pair of light reception elements, and each pixel
is arranged using two pixels related to the pair of light
reception elements as pixel units.
15
9. The image capture element according to claim 1,
wherein two light reception elements of light reception
elements of the plurality of phase difference detection
pixels which perform pupil division in an identical
20 direction and receive light divided in one way of the
identical direction form a pair of light reception
elements, and each element is arranged using two pixels
related to the pair of light reception elements as a
pixel units.
25
10. The image capture element according to claim 1,
wherein
the first pixel group comprises a first line formed
by arranging in the specific direction the phase
30 difference detection pixels to be pupil-divided in the
specific direction and a second line formed by arranging
in the s p e c i f i c direction the phase difference detection
pixels t o be pupil-divided i n the orthogonal direction,
and
the f i r s t l i n e and the second l i n e are a l t e r n a t e l y
5 arranged across the second pixel group.
11. The image capture element according t o claim 10,
wherein
the phase difference detection pixel comprises a
10 p l u r a l i t y of phase difference detection pixels
corresponding t o a p l u r a l i t y of e x i t pupils provided a t
different positions in an optical axis direction, and
the f i r s t l i n e is formed by arranging phase
difference detection pixels of the p l u r a l i t y of phase
15 difference detection pixels comprising the e x i t pupils
provided a t an i d e n t i c a l position.
12. The image capture element according t o claim 10,
wherein
20 the p l u r a l i t y of phase difference detection pixels
comprise a p l u r a l i t y of phase difference detection pixels
corresponding t o a p l u r a l i t y of e x i t pupils provided a t
d i f f e r e n t positions i n an axial direction, and
the second l i n e is formed by arranging phase
25 difference detection pixels comprising the e x i t pupils
provided a t an i d e n t i c a l position, a t a position
identical t o a position in the s p e c i f i c direction.
13. An image capture element comprising:
3 0 a p l u r a l i t y of phase difference detection pixels
which generate signals for performing adjusted focus
decision by way of phase difference detection; and
a plurality of image generation pixels which
generate signals for generating an image,
wherein each of the plurality of image generation
5 pixels has a fixed ratio of the phase difference!
detection pixels and the image generation pixels for each
neighboring pixel in an area of the image capture element
which receives subject light. (
10 14. An imaging device comprising:
an image capture element which comprises a
plurality of phase difference detection pixels which
generate signals for performing adjusted focus decision
by phase difference detection and a plurality of image
15 generation pixels which generate signals for generating
an image, wherein a first pixel group which is formed by
arranging part of phase difference detection pixels of
the plurality of phase difference detection pixels in a
specific direction, and a second pixel group which is
20 formed by arranging part of image generation pixels of
the plurality of image generation pixels in the specific
direction are alternately arranged in an orthogonal
direction orthogonal to the specific direction;
an focus adjustment decision unit which performs
25 adjusted focus decision by way of phase difference
detection based on the signals generated by the phase
difference detection pixels; and
an image generation unit which generates an image
based on the signals generated by the image generation
30 pixels.