TITLE 01: INVENTION: NAVIGATION DEVICE
5 TECFXNICAL FIELD
[OOQl] The present invention relates to a navigation device that can display a detailed
screen on a portion of a large-area map screen and move the detailed screen arbitrarily
thereon.
l o BACKGROUND ART
[0002] A device is known which displays a slave screen at a display position in a display
screen for displaying a large~aream ap and displays an enlarged detailed map of the
display position in the slave screen (cf., for example, Patent Literature 1). With this device,
the slave screen can be moved within the display screen.
15
CITATION LIST
PATENT LITERATURE
[0003] Patent Literature 1: Japanese Laid Open Patent Publication No. 2007-72233 A
2 0 SUMMWCy 01: TNVENTI'ON
TECI-INICAL PROBLEM
[0004] With tthe device that is described in the above described Patent Literature 1,
attempting to move the position of display of the slave screen so as to follow the
movernent of a finger that touches the slave screen, while the slave screen is moving, the
2 5 content of display of the enlarged map on the slave screen is not updated and as a result
the enlarged map cannot be checked while it is moving. Therefore, when the slave screen
is to be moved in order to find out a target object on the map, a series of operations must
be done repeatedly, That is, after the movement, the slave screen is stopped for checking
the content of the display. If the target object is not displayed yet, the position of the slave
30 screen is further moved and stopped for awaiting update of the slave screen and checking
the content thcreof again. Therefore, the slave screen cannot be moved smootl~lyto a
target destination.
SOLUTION TO PROBLEM
, - . - - - - , *..",
[0005] A navigation device according to the claim 1 characterized by comprising: a map
display means for displaying a large-area map screen showing a large-area map and
displaying an enlarged map screen showing a partial enlarged map obtained by enlarging a
partial region of the large-area map in superposition on the large-area map screen at a
5 display position of the partial region; a speed calculation means for calculating a speed
pertaining to movenlent of the enlarged map screen; an enlarged map creation means for
creating an enlarged map obtained by enlarging a predetermined region including the
partial region of the large-area map based on vector data of a detailed map obtained by
enlarging tho large-area map; and a selection means for selecting the partial region of the
10 large-area map as the partial enlarged map when the speed pertaining to the movement is
no lower than a reference speed and selecting a region of the enlarged map, corresponding
to the partial region, as the partial enlarged map when the speed pertaining to the
movement is lower than the reference speed.
15 ADVANTAGEOUS EFFECT OF TEFE WENTION
[0006] According to the present invention, while the slave screen is moving at a speed
higher than a predetermined speed, an image of the large-area map is displayed in enlarged
scales, so that the slave screen can be moved while checking tho range of the enlarged
map displayed on the slave screen, Enlargement processing for enlarging the image ofthe
2 0 large-area map can be performed at a speed higher than vector map creation processing.
This enables high speed movement of the slave screen. When the slave screen approaches
to the target place and its moving speed becomes slower than a predetermined value, an
image that is created according to a vector map method that enables display of detailcd
information is displayed. As a result, it becomes possible to chcck the target objects. This
25 method makes it possible to move the display posilion of the slave screen to a desired
target place smoothly.
BRIEF DESCWTION OF TEIE DRAWINGS
[0007] [FIG. 11 FIG,l is a diagram showing a functional construction of a navigation
30 device according to an embodiment of tho prcscnt invention.
[FIG. 21 FIG. 2 is a diagram showing an example of display during the movement
of a slave screen.
[FIG. 33 FIG, 3 is a diagam illustrating a region that is displayed neither in a
large-area map screen nor in a slave screen as a result of display of the slave screen.
[FIG, 41 FIG. 4 is a diagram showing an example of display when the display of
the slave screen is started.
[FIG. 53 FIG. 5 is a block diagram showing details of an ulnlarged map display
function.
5 [FIG: 61 FIG. 6 is a flow diagram illustrating a process of displaying an enlarged
map,
[FIG, 73 FIG; 7 is a flow diagram illustrating a process of obtaining a threshold
value for judging movement speed of a slave screen.
[FIG. 83 FIG. 8 is a functional block diagram according to a variation example for
10 changing the shape of the $lave screen into a desired shape.
[FIG. 91 FIG, 9 i s a flow diagram illustrating a process of changing the form of
the slave screen into a desired shape according to the variation example,
[FIG. 101 FIG. 10 is a functional configuration diagram illustrating a variation
example in whicl~th e slave screen is displayed when scroliing the large-area map.
25 [FIG. 1 I] FICx 11 is a flow diagram illustrating a processing according to a
variatiori example in which the slave screen is displayed when scrolling the large-area
map.
BESCICrPTIQN OF EMBODIMENTS
2 0 [0008] Hereafter, referring to the drawings, a navigation device according to an
embodiment of the present invention is explaincd.
[0009] Screens of conventional navigation devices have smaller display areas than thosc
of paper maps and does not fit to display a detailed wide-mnge map well. Thus, therc has
been conventionally adopted a display method in which the display screen is divided into
25 two, one displaying a large-area map and a~othcdr isplaying a detailed nlap, and
displaying them at the same tima. However, with this metllod, it is difficult to intuitively
understand the relationship between the detailed map and tIie large-area map. It is also
difficult to freely alter the size ofthe display area of each map. Therefore, according to the
present invention, there is adopted a method in which a detailed ,nap is displayed as a
I
30 slave screen provided in a display screen for displaying a large-area map and the slave
screen is configured to be movable to a desired position in the large-area map display
screen freely and at high speed. The navigation device can alter the display position of the
slave screen following a high speed movement of the finger that is detected by a touch
panel or the like attached to the display screen. This configuration enables one to
intuitively understand the positional relationship between the large-area map screen and
the detailed screen and in addition, enables the position ofthe slave screen to be moved
freely at high speed, As a result the display of the large-area map and the detailed map can
be altered at a desired point Here, a large-area map means a map that is displayed on a
5 display screen of the navigation device, with the map having a scale larger than the scale'
of the detailed map that is displayed on the slave screen within the display screen of the
navigation device.
[OOXO] FIG 1 presents a functional configuration diagram illustrating a navigation device
for implementing the present invention. A navigation device 5 is provided with a
10 large-area map display screen (large-area map screen) for showing a large-area map and,
as a slave screen, an enlarged map screen that displays a detailed pxtial enlarged map
showing a partial region among the large-area map. The slave scree4 can be moved within
the display screen for a large-area map (large-area map screen) freely. The navigation
device has the following construction. As the construction for displaying a largo-area map,
15 the navigation device 5 includes large-area map data 40 expressed in rhe fonn of vector
data, a large-area map creation processing unit $0 that: creates a map using the data, a
large-area map creation buffer 60 that: stores a result of creation by the large-area map
creation processing unit SO in raster data format, a superposition processing unit 70 that
synthesizes displays of a large-area map and a detailed map, a frame buffer 80 that stores a
20 result of syntl~esisb y the superposition processing unit 70, and a display processing unit
90 that displays a large-area map screen 95 and a slave screen 97,which will be explained
later, bnsed'on the data in the frame buffer 80.
[0011] When displaying a slave screen, if the slave screen moves at high speed, vector
creation processing by an enlarged map creation processing unit 101 could not proceed in
25 time with the movement of the slave screen. Accordingly, according to the present
invention, when the slave screen moves at a speed higher than a predctcrmined speed, a
raster map created in the large-area map creation buffer 60 is magnified and displayed,
thereby making it possiblc for the slave screen to follo~vu p the movement of the finger.
For this purpose, the enlarged map display processing unit 10 includes an enlarged map
30 screen movement detection Gocessing unit 20 that detects the movement of an enlarged
map by an operation sensed by a sensor such as a touch panel, an enlarged map creation
processing unit 101 that creates an enlarged map using detailed map data 30 containing
vector data based on the result of the detection, a raster image enlargement processing unit
102 that enlarges a partial raster image in the large-area map creqtion buffer 60, a speed
4
cdculation processing unit 103 that calculates the moving speed of the slave screen upon
movement of the slave screen detected by the enlarged map scrcen movement detection
processing ul~i2t 0, and a selection processing unit 104 that selects either one of the
detailed map created by the enlarged map creation processing unit 101 and the map that is
5 enlarged by the raster imagc enlargement processing unit 102 on the basis of the result
from the speed calculation processing unit 103.
[0012] FIG. 2 shows an exemplary display of the slave screen (i.e., enlarged map screen)
97 that is displayed in superposition on the large-area map screen 95 at a display position
of a partial region in the large-area map screen 95 that displays a largc-area map. When
10 the user moves his or her finger 96 touching the slave screen 97 and thus alters the touch
position of the finger 96 in the large-area map screen 95, the slave screen 97 is moved
following the movement of the finger 96. Thc enlarged map screen movement detection
processing unit 20 detects the movement of the slave screen 97. An enlarged figure of thc
raster image in the large-area map crcation buffer 60 is displayed on a slave screen 97-1
15 that is moving at high speed. Thereafter, on a slave screen 97-2 whose moving speed
becomes slower, a detailed map created by the enlarged map creation processing unit 101
is displayed.
[0013] When a slave screen is displayed on the large-area map screen, there occurs a
region that is displayed neither on the slave screen nor on the latge-area map screen. FIG.
20 3 presents a diagram that illustrates that a part of the large-area map screen 95 is not
displayed. The screen is scen in a direction perpendicular to the cross-scction. Although
actually, the slave screcn 97 is not lifted up from the large-area map screen, the slave
screen 97 is illustrated so, in order to emphasize the part that is not displayed. The part
that is not displayed occurs because the scale size of the slave screen is of detailed size
25 ratl~erth an that of the large-area map screen so that there is created a diiTerence between a
region that can be displayed by the slavc screen 97 and a large-area map region that is
shown by the large-area map screen 95 that is displayed behind the slave screen. When the
level of detail in the slave screen 97 is increased (i.e., when the difference between scale
sizcs of the large-area map and the detailed map bccomes greater), the region that is not
30 displayed increases. As a result, a periphery of the destination to whicll the slave screen
moves becon~eso ut of sight and it becomes difficult to set a target for the destination for
which the slave screen moves, Accordingly, in order to enable one to find out the target
position of the movement of the slave screen 97 quickly, in the present invention, the
enlarged map of raster image in the lage-area map creation buffer 60 is switched to a lnap
5
created using vector data, of the detailed map data 30 before the moving speed of the slave
screen 97 is slowed down to a speed that is no faster than a predetermined specd and the
movement of the slave screen 97 is stopped. Wit11 this configuration, when it is necessary
to move the slave screen 97 at high speed, an image of the large-area map that is enlarged
5 by raster image enlargement processing is displayed to clearly show the display range of
the enlarged map. When the moving specd of the slave screen 97 is slowed down, detailed
inforn~ationis displayed on the slave screen 97 so as to make one easier to find the target
of destination of movement of the slave screen 97.
[0014] FIG. 4 illustrates an operation example when the display of an cnlarged map is
10 started. Before the enlarged map is displayed, the display of an operation button 98 on the
screen is "ENLARGED MAP ON" as shown in FIG. 4(a). This is touched by the finger 96.
Then, a place of which it is desired to display an enlarged nlap is touched. As a result the
slave screen 97 for that place is displayed in that place and the display of the operation
button 98 is altcred to "ENLARGED MAP OFF" as shown in FIG 4(b). At this moment,
s5 the enlarged map creation processing unit 101 starts creation of an enlarged map. If it is
expectcd that it t&es a relatively long time before creation of the enlarged map is
completed, the image of that place of the enlarged map in the large-area map creation
buffer 60 is enlarged and displayed by the raster image enlargement processing unit 102.
Thereatler, upon oompletion of the creation by the enlarged map creation processing unit
20 101, the display is switched to the created image as shown in FIG. 4(c). This shortens the
time t&en from the start of the operation to the display of the enlarged map, thus
increasing the handleability. "ENLARGED MAP OFF" is touchcd by the finger in order to
stop the display of the slave screen 97.
[OOlS] FIG, 5 presents a detailed configuration diagram illustrating functions of the
2 5 enlarged nrap display processing unit 10. An enlarged map region control processing unit
105 controls correspondence bctwcen a position within the display screen and
geographical coordinates. Geographical coordinates determine a geograplu~dp oint
uniquely, such as longitude and latitude or mesh number and XY coordinates in the mesh
an a map. The enlarged map screen movement detection processing unit 20 outputs a start
30 point of display of an enlarged map and an amount of movement of the enlarged map
screen in terms of geographical coordinates. The amount of movement is obtained as
follows. The movement of the finger 96 is detected in intervals of, for example, 1/30
seconds and the amount of movement of the finger 96 for 1/30 seconds is converted into
geographical coordinates, This is calculated as follows. Whcn a range of geographical
coordinates displayed in the scale of the enlarged map created by the large-area map
creation processing unit SO is divided by the nuniber of pixels of the display scrccn, a
distance in geographical coordinates per pixel is obtained. The amount of movement can
be obtained by multiplying the number of pixels over which the finger 96 has moved by
5 the distance in geographical coordinates per pixel.
[0016] The enlarged map creation processing unit 101 creates an enlarged map by
enlarging the enlarged map expressed in geographical coordinates output by the enlarged
map region control processing unit 105, according to a magnification factor I06 set by the
magnification factor setting processing unit 35, using the vector data of the detailed map
10 data 30. The created data may be stored in an enlarged map creation buffer 109 as raster
data. When a selection processing unit 104 selects the enlarged map data created by the
enlarged map creation processing unit 101, the selection processing unit 104 may directly
select the enlarged map data or the selection processing unit 104 may select the raster data
stored in the creation buffer 109 as described later. In the foIlowing explanation, it is
15 assumed that the enlarged map data created by the enlarged map creation processing unit
101 is stored in the enlarged map creation buffer 109 as raster data. Desirably, the size of
the above enlarged map creation buffer 109 is greater than the display range of the slave
screen 97 so to include the display range of the above slave screen 97 and preferably
corresponds to the amount of data of the enlarged map obtained by enlarging a
20 predetermined region having a size not greater than the size of the display screen, When
the moving speed of the slave screen 97 becomes no greater than i! predetennined speed,
the above enlarged map creation processing unit starts creation of an enlarged map, and
thorefore the movement of the slave screen 97 is continued while the creation processing
is being continued. Therefore, the position in which the creation started is deviated from
25 the position in which the movement of the slave screon 97 is stopped. It is necessary that
an enlcuged map including this range of deviation is created in the enlarged map creation
buffer 109. However, if the enlarged map creation buffer 1.09 is too large, time for the
creation processing becomes too long, so that there is a fear that the creation is not
con~pletedb efore the slave screen 97 is stopped.
30 [0017] An enlarged map screen display region protrusion detection processing unit 107
and an enlarged map screen position control processing unit 108 detects whether or not the
region to be displayed by the slave screen 97 protrudes from the region of the enlarged
map created in the enlarged map creation buffer 109 (i.e., the above predetermined region)
when the display of the slave screen 97 is started or as a result of movement thereof.
- . . - - - - -,
This judgment of region is performed using geographical coordinates. That is, if the region
after the slave screen 97 h~ moved (i.e., the region after a partial region of the large-area
map has been altored) is included in the region of geographical coordinatcs created in the
enlarged map creation buffer 109, it can be judged that there is "no" protrusion. If any
5 protrusion is detected, the enlarged map creation processing unit 101 starts creation of an
enlarged map of the relevant rcgion. During the creation of it, the raster image
enlargement processing unit 102 reads out rastef data of the relevant region from the
large-area map creation buffer 60 for enlargement processing and stores the resultant data
in the rasrer enlargement buffer 110. The result is selected by the selection processing unit
10 104 and synthesized as the slave screen 97 with the large-area map screen 95 that shows a
large-area map by the suporposition processing unit 70. This state is as shown in FIG. 4(b).
Thereafter, after the creation by the enlarged map creation processing unit 101 is
completed, the selection processing unit 104 selects data in the enlarged map creation
buffer 109 and outputs it to the superposition processing unit 70. This state is as shown in
15 FIG. 4(c). Wile the slave screen 97 is moving, the speed calculation processing unit 103
divides a distance of movement per 1/30 seconds of the finger 96 by 1/30 seconds to
obtain a tnoving speed of the slave screen 97. As a result, in case where the nloving speed
is faster than a reference specd 1040, the selection processing unit 104 selects the image in
the raster enlargement buffer 110 (cf., the state of 97-1 in FIG, 2) and in a case other than
20 that, the sclection processing unit 104 selects the illrage in the enlarged map creation
buffer 109 (cf., the state of 97-2 in FIG 2), and outputs the selected image to the
superpositi~np rocessing unit 70.
[0018] FIG, 6 presents a flow diagram illustrating the above operations. First, the
aperation button 98 madced "ENLmCrED MAP ON" that is displayed on the large-area
25 map screen 95 is prcsscd and start of display ofthe enlarged map is waited for (step S100).
Then, the position of the slave screen 97 is compared with the range of the enlarged map
in the enlarged map creation buffer 109 and whether or not a partial enlarged map
obtained by enlarging a partial region of the large-area map and shown by the moved slave
screen (i.e., enlarged map screen) 97 is included within the region of!l~e enlarged map
30 created in the eplarged map creation buffer 109 (i.e., predetermined region) is judged by
the enlarged map screen display region protrusio~detection processing unit 107 and the
enlarged map screen position control processing unit 108 (step S110). As a result, whcn it
is detected thpt a partial enlarged map to be displayed (is., partial enlarged map in which a
partial region after alteration is enlarged) is included within the region of the enlarged map
(i,e., predetermined region) in the enlarged map ereation buffer (cf,, "YES" in step S120),
control proceeds to step Sl50. The image of the partial enlnrged map that is obtained by
enlarging the padial region after alteration i s rcad out from the enlarged map creation
buffer 109 (i.e,, selected) by the selection unit 104, and synthesized with the large-area
5 map by the superposition processing unit 70 (step SlSO), When it is detected that thc
partial enlargcd map obtained by enlarging the partial region after altcration is not
included in the above predetermined region (cf., "NO" in step S120), the image of the
portion of relevant place (the partial region after alteration) in the large-area map is read
out from the large-area map creation buffer 60 and the image enlarged by the raster image
10 enlargement processing unit 102 i s selected by the selection processing unit 104 and is
defmed as a partial enlarged image. The partial enlarged image ik superposed on the
large-area map by the superposition processing unit 70 so as to perform synthesis
processing (step 5130). That is, the enlarged map screen is displjvyed in supesposition on
the lwge-area map screen. In parallel with this processing, another enlarged map obtained
15 by enlarging another predete~nedre gion including relevant place (i.e., the partial region
after alteration) is created by the enlarged map creation processing unit 101 (step S140).
[0019] After completion ofthe above creation, raster data of the image of the paxtid map
of relevant place (i.e., the other enlarged map above) is read out from the enlarged map
creation buffer 109 (selected) by the selection unit 104. The enlarged map obtained by
2 0 reading out the rater data is superposed on the large-area map by the superposition
processing unit 70 to be synthesized with the large-area map (step S150). This state
corresponds to the display shown in FIG. 4(c). That is, the enlarged map screen (i.e,, slave
screen 97) is displayed in suporposition on the large-area map screen 95, Thereafter, it is
judged whether or not the operation of completion of display of the slave screen 97 is
25 performed by operation of the operation button 9s (step S160). In case of "NO", it is
judged whether or not the slave screen 97 is moved (step S170). This judgment is
performed for every 1/30 scconds. If any movement of the slave screen is detected, the
speed calculation processing unit 103 calculates the moving speed of the enlarged map
screen based on the respective positions before and after the movement thereof (step
30 Sl80). A!: a resuIt, it i$ judged whether or not the above moving speed is no lower than a
threshold value, which is tlie reference speed 1040 (step S190). If the moving speed is no
lower than the threshold value (i,e., no lower than the reference speed 1040), the image of
the partial map of relevant place i s read out from the large-area map creation buffer 60 and
enlarged by the raster image enlargement processing unit 102 to obtain an enlarged image,
which image is synthesized with the lacge-wea map by the sppe~ositionp rocassing unit
70 (i.e., the enlarged map screen is superposed on tile large-area pap screen) (step 8200)
and control returns to step 81 10. On the other hand, if the moving speed is lower than the
threshold value (i.e., 1~wetrh an the reference speed 1040), col~tr~r)elt urns to step SllO
5 straightfowardly.
[0020] FIG. 7 presents a flow diavanl illustrating a method of (?hanging the reference
speed 1040 in case where the moving speed of the slave screen 97 is altered hm high
speed to low speed and in case where the moving speed of the slqve scrcen 97 is altered
fron~lo w speed to high speed. When the slave scrcen 97 moves at a speed around the
//
10 reference speed 1040, it is supposed that speeds over and under this threshold value are
repeatedly obtained frequently. In such a case, the slave screen 97 displays thereon the
image in the raster enlargement buffer 11 0 (cf., 97-1 in FIG. 2) and the image if1 the
enlarged map creation buffer 109 (cf., 97-2 in FIG: 2) alternately in a repealed manner.
This causes the display screen to blink, providing a display which is hard to see. Thus,
15 different threshold values are used, i.c., a first threshold value which is used when the
moving speed of the slave screen 97 is altered from below to above (exceeding) the
reference speed 1040 and a second threshold value which is used when the moving speed
of the slave screen 97 alters &om above to below (falling below) the reference speed 1040
to prevent blinking of tl~ed isplay screen from occurring. This processing illustrated in
20 FIG,7 is performed right before the step S190 shown in FIG6. Firstly, the moving speed
this time and the moving speed immediately before this time (1130 seconds before) are
compared. In case where the moving speed this time is not slower than the moving speed
immediately before (step S3 15), the first threshold value is defined as the reference speed
1040 (step $320). On the other hand, in case where the moving speed this time is slower
25 than the moving speed immediately before (step S310), the second threshold value, which
is by about 10% smaller than the first threshold value, is defined as the reference speed
1040 (step S320).
[0021] The navigation device 5 according to the present embodiment includes a display
processing unit 90 that displays on a display screen thereof a large-area map screen 95 that
30 shows a large-area map, and also a slave screen (enlarged map screen) 97 that displays a
map obtained by enlarging a partial region of the large-area map at a display position of
the partial region in superposition on the large-area map screen 95; a speed calculation
processing unit 103 that calcylntes a moving speed of the enlarged map screen 95; an
enlarged map creation pr~cessingu nit 10 1 that creates an enlarged map obtained by
enlnrging a predetermined region including the above partial region based on the detailed
map data 30 obtained by enlarging the large-area map; and a selection processing unit 104
that selects a map based on raster data of the partial region as a map that is to be displayed
by the slave screen 97 when the moving speed is no lower than the reference speed 1040,
5 and that sclects a map based on raster data of a region of the above enlarged map,
corresponding to the above partial region, as a map that is to be displayed by the slave
scrcen 97 when the moving speed is lower 01an the reference speed 1040. Therefore, the
slave screen 97 can be moved tleely and at high speed to a desired position within a
predetemined region within t l i ~la rge-area map screen 95.
10 [0022] It is preferred that the navigation device 5 according to the present embodiment
further includes an enlarged map screen display region protrusion detection processing
unit 107 and an enlarged map screen position control processing unit 108 that detect that
the above partial region after the movement of the slave screen 97 is not included in tlie
above predetermined region. In case wbece the moving speed of the slave screen 97 is
15 lower than the reference speed 1040 and it is detected by the enlarged map screen display
region protrusion detection processing unit 107 and the cnlwged map screen position
control processing unit 108 that the above partial region is not included in the above
predetermined region, the selection processing unit 104 solccts the map based on the raster
data of the above partial region as the map to be displayed by the slave screen 97 until the
20 enlarged map creation processing unit 101 creates another enlarged map obtained by
enlarging another predetermined region including the above partial region that has been
altered. Therefore, the slave screen 97 can be moved freely and at high speed to a desired
position within the large-area map screen 95.
[0023] It is preferred that in the navigation device 5 according to the present
2s embodiment, the reference spced 1040 is the first threshold value when the moving speed
becomes higher than the reference speed 1040 while the reference speed 1040 is the
second threshold value, which is smaller than the first tlueshold value when the moving
speed becomes lower than the reference speed 1040. With this configuration, the display
of the slave screen is performed so as to prevent the image in the raster enlargement buffer
30 110 (cf., 97-1 in FIG. 2) and the image in the enlarged map creati,on buffer 109 (cf, 97-2
in FIG. 2) from being alternately displayed in a repeated manner ~ ntdhu s to prevent the
display screen from becoming difficult to be seen.
[0024] It is preferred that the navigation device 5 according to the present embodiment
further includes an enlarged map scrcon movement detection processing unit 20 that
detects the movement of the slave screen 97 when the user contacts the slave screen 97
and alters the contact position within the large-area map screen 95. The moving speed
calculated by the speed oalculation processing unit 103 is the moving speed ofthe slave
screen 97 when the nlovernent of the slave screen 97 is detected by thc onlarged map
5 screen movement detection processing unit 20. Therefore, the slave screen 97 can be
moved freely and at high speed to a desired position within the large-area map screen 95.
[0025] --- VARIATION EmMPLES ---
(1) FIG 8 presents a diagrm illustrating a method of displaying the slavc screen
97 in a desired form instead of a rectangular shape. The sul;erposition processing unit 70
10 extracts and displays the contcnt in the enlarged map creation buffer 109 according to a bit
pattern recorded in a mask pattern 11 1. With this variation example, for example, it is
assumed that the shape of shaded area with hatched lines of the n1ask pattern 111 is
expressed by 1 and the inside of a circle is expressed by 0, Then, in the portion expressed
by 1, data in the large-area map creation buffer 60 is selected and in the portion expressed
15 by 0, data in the enlarged map creation buffer 109 is selccted. The selected one is
displayed as the slave screen 97.
[0026] FIG. 9 presents a flow diagram illustrating the processing shown in FIG 8, First,
one woid (here, 32 bits are supposed) is read out from the mask pattern 111 (step 5400).
Since the mask pattern 11 1 contains one bit per pixel, data for 32 pixels is read out by the
20 above process. Then, the data read out from the mask pattern 11 1 is shifted by one bit
leftward (step S405). As a result the lehost one bit is put out as a carry bit and it is
possible to determine whether that bit is 1 or 0 (step S410). As a result, if that bit is 0, onc
pixel to be displayed is read out from the enlarged map crcation buffer 109 (step 541 5), or
if that bit is 1, one pixel to be displayed is read out fiom the large-area map creation buffer
2 5 60 (step S420). Then, the read out data is written into a region of the enlarged map 107
within a frame buffer 80 (step 542.5). Thereafter, the read out address of the large-area
map creation buffer 60 is updated (stcp S430), thc read out address of the enlarged map
creation buffer 109 is updated (step S435), and the write in address of the fmme buffer 80
is updated (step $440). After all the shift processing for one word of ttle mask pattern 11 I
30 is completed (step S445), fl~ere ad out address of the mask patter~l1 1 1 is updated (step
5450). The above processing is repeated until processing for alI the pixels is completed
(step S455). If the selection processing unit 104 has selected the raster enlargement buffer
11 0, an enlargement buEec 110 is used instead of the enlarged map creation buffer 1.09 in
steps $415 and S435 in FIG. 9. In this method, the shape of the slave screen 97 can be
altered freely by altering the pattern shape of the mask pattern 11 1.
[0027] In the navigation device 5 according to the variation example (I) above, a shape
of the slave screen 97 is not limited to a rectangular shape and may be any desired shape.
[0028] (2) FIO. 10 presents a configuration diagram illus@ating functions of processing
5 of the slave screen 97 whon a large-area map as a background or substratum is being
scrolled, Xn this case too, one ofthe data in the enlarged map creation buffer 109 and the
data in the large-area map creation buffer 60 in the display ofthe slave screen 97 is
switched to the other of the data in the enlarged map creation buffer 109 and the data in
the large-aroa map creation bufTer 60 depending on a difference in speed of scrolling the
10 large-area map. With this configuration, an enlarged map can be displayed cvcn when the
large-area map is being scrolled at high speed. The configuration of FIG. 10 is made up by
replacing the enlarged map screen movement detection processing unit 20 in FIG 5 by the
large-area map screen movement detection processing unit 25. When an operation is
performed to scroll the large-area map, the large-area map screen movement detection
15 processing unit 25 creates a map that is obtained by moving by a distance in which the
large-wea map is scrolled in the large-area map creation processi~lgu nit 50. The method
of scrolling the large-area map may be a method in which a finger that touches the
large-area map screen is moved, with the finger being kcpt in contact therewith.
[0029] FIG. 1 l presents a flow diagram illustrating the configuration of FIG. 10,
2 0 Whether or not the scrolling operation for the large-area map has been occurred is
determined at intervals of, for example, 1/30 seconds (step S500). If rJle scrolling
operation has been occurred, a large-area map is created such that the display position is
shifted as much as the finger has moved and the result is stored in the large-area map
weation buffer 60. On this occasion, the portion of the image before the scrolling that is
2 5 displayed even after the scrolling is copied after shifting by an dnount in which the image
is scrolled in the largo-area map creation b~ffer6 0 and a deficit /sa dded. By creating the ~
image in this manner, processing time can be shonened as compared with creating the
whole imago. Therefore, since the smaller the amount of movement by scrolling, the
smaller the amount of addition, so that it is possible to perform the processing at high
30 spced. On the contrary, the larger the amount of movement by scrolling (high spced
scrolling), the longer the creation processing time is. For this reason, it is necessary to
reduce the whole processing load by reducing creation processing of the slave screen at
Che high speed scrolling.
[0030] Movement af the large-area map displayed on the large-area map screen 95 by
scrolling causes the large-area map screen to be altered, Although the position of the
enlarged map screen (i.e,, slave screen 97) that is displayed in the large-area map screen is
not altered, a partial region of the large-area map that is enlarged in the partial enlarged
map shown on the enlarged map screen is altered according to the movement ofthe
5 large-area map due to the alteration of the large-area map screen, In this case, the amount
of the large-area map screen corresponds to the amount of scroll and the moving speed of
the enlarged map screen corresponds to the speed of scroll.
[0031] Thcn, the moving speed of the enlarged screen is calculated by speed calculation
processing unit 1.03 based on the positions before and after movement of the large-area
10 map (step S510). It is determined whether or not the above speed is no lower than the
value of the refercncc spccd 1040 (LC., threshold value) (step SS20). If the moving speed
is no lower than the threshold value (i.e., no lower than the reference speed 1040), an
image of a partial map of the place is read out from the large-area map creation buffer 60
and is enlarged by the raster image enlargement processing unit 102. The enlarged image
15 is synthesized with the large-area map by the superposition processing unit 70 (i.e., the
enlarged map screen is superposed on the large-area screen). By so doing, while the
large-area map is being scrolled.at high speed, vector map creation processing can be
eliminated, so that the entire processing load can be reduced.
[0032] On the other hand, when the scroll speed is lower than the threshold value, it is
20 determined whether or not the partial enlarged map to be displayed on the slave screen
(i.e., the partial enlarged map obtained by enlarging a part of region after the alteration) is
included in the region of the enlarged map created in the enlarged map creation buffer 109
(i.e,, predetemiined region) (steps S530 and S540), If included, an image of the partial
enlarged map obtained by enlarging a part of the region after the alteration is read out (is.,
25 selected) from the enlarged map creation buffer 109 by the selection processing unit 104.
The image of the partial enlarged map is superposed on the large-area map by rhe
superposition processing unit 70 to perfom1 synthesis processing (step S550), That is, the
enlarged map screen is displayed as superposed on the large-area map screen. If not
included, an image of thc portion of relevant place in the large-area map (LC., the partial
3 0 region after the alteration) is read out from the large-area map creation buffer 60. The read
out image is enlarged by raster image enlargement processing unit 102. The enlarged
image is selected by the selection processing unit 104, This i s used as the partial enlarged
image, The partial enlarged image is superposed on the large-are? map by the
superposition processing unit 70 to be synthesized with the large-area map (step S570).
14
Along with this processing, another enlarged map (is., another detailed map) obtained by
enlarging anothes predetermined region including the relevant place (Lea, the partial regiol~
after the alteration) is created by the enlarged map creation processing unit 101 (step
S580). Aftm completion of the above creation processing, raster data of the image of the
3 partial map of the relevant place (i.e,, the above another detailed map) is read out from thc
enlarged map creation buffer 109 and the detailed map of which the raster data has been
read out is superposed on the large-area map by the superposition processing unit 70 to be
synthesized with thc large-area map.
[0033] Preferably, the navigation device 5 according to Variatian Example (2) further
10 includes a large-area map screen movement detection processing unit 25 that detects that
the large-area map displayed on the large-area map screen 95 ha? been moved by scrolling
it, in addition to thc construction of the navigation device 5 according to the above
embodiment. The movement of the slave screen 97 is perfomled by alteration of the above
partid region in accordance with the movement of the large-area map by scrolling it and
15 the speed calculation processing unit 103 calculates a scrolling speed upon the scrolling.
Therefore, the slave screen 97 can be moved freely and at high speed to a desired position
in the large-area map screen 95.
[0034] As described above, according to the present invcntion, it is possible to display an
enlarged map in both cases while the enlarged map is moving at high speed and while the
2 0 large-area map is being scrolled at high speed,
REFERENCE SIGNS LIST
[O035] 5 navigation device
10 enlarged map display praccssing unit
25 20 enlarged map screen movement detection processing unit
25 large-area map screen movement detection processing unit
30 detailed map data
35 magnification factor setting processing unit
40 large-brea map data
30 $0 large-area map creation proccssing unit
60 large-area map creation buffer
70 superposition processing unit
80 frame buffer
90 display processing uni.t
95 large-area map screen
97 slave screen
101 enlarged map creation processing unit
102 raster image ~cnlwgamenpt rocessing unit
5 103 speed oalculation processing unit
104 seteotion processing unit
105 enlarged map region control processing unit
106 magnificntion factor
107 entatgad map screen display region protrusion detection processing unit
1 Q 108 enlarged map screen position control processing unit
109 enlarged map creation buffer
1 10 raster enlargement buffer
11 1 mask pattcsrn
1040 reference specd

CLAIMS
1. A navigation device, comprising:
a map display means foq displaying a large-area map screen showing a large-area
5 map and displaying an enlarged map screen showing a partial enlarged map obtained by
enlarging a partial region of the 1,qge-area map in superposition on the large-area map
screen at a display position of the partial region;
a speed calculation means for calculating a speed pertaining to movement of the
enlarged map screen;
10 at1 enlarged map creatiop means for creating an enlarged map obtained by
enlarging a predetermined region including the partial region of the large-area map based
on vector data of a detailed map obtained by enlarging the lar'ge-area map; and
a selection means for s~lectingth e partial region of the large-area map as the
pwial enlarged map when the speed pertaining to the movement is no lower than a
15 reference speed and selecting a region of the enlarged map, corrqonding to the partial
region, as the partial enlarged map when the speed pertaining to the movement is lower
than the reference speed.
2. A navigation device according to claim 1, further complising:
20 a protrusion detection means for detecting that the partial region after the
movement of the large-area map screen is not included in the predetermined region,
wherein
when the speed pertaining to the movement is lower than the reference speed and
the protrusion detection means detects that the partial rcgion is not included in the
25 predetermined region, until the enlarged map creation means creates another enlarged map
obtained by enlarging another predetermined region including the partial region altered,
the selection means selects the partial region altered of the large-area map as the partial
enlarged map.
30 3. A navigation device according to claim 1 or 2, wherein
the reference speed is a first threshold value when the speed pertaining to the
movement becomes higher than the reference speed; and
the reference speed is a second threshold value that is smaller than the first
threshold value when the speed pertaining to the movement becomes lower than thc
17
reference speed.
4. A navigation device according to any one of claims 1, through 3, further
comprising:
5 an enlarged map screen movement detection means for detecting the movement
of the enlarged map screen when a user contacts the enlarged map screen and alters a
contact position within the large-area map screen, wherein
the speed pertaining to the movemeni calculated by the speed calculation means
is a moving speed of the enlarged map screen when the movement of the enlarged map
10 screen is detected by the enlarged map screen movement detection means.
5, A navigation device according to claim 1 or 2, fi~rthecr omprising:
a large-area map screen movement detection means for detecting that the
enlarged area map shown by the large-area map screcn has been poved by scrolling the
15 large-area map screen, wherein
the movement of'the enlarged map screen is perfom~edb y alteration oftlie partial
I
region in accordance with the movenxent of the large-area map by the scrolling and the
speed pertaining to the movement calculated by the speed calculation means is a scroll
speed upon the scrolling.
20
Dated this llthDa y of April 2014