2
FIELD OF THE INVENTION
[0001]The present invention relates generally to an imaging system, and more
particularly to a portable endoscopic imaging device of the imaging
system.
BACKGROUND OF INVENTION
[0002]Minimally invasive procedures or surgeries (MIP or MIS), including
endoscopic, laparoscopic, endoscopically-assisted, or laparoscopically-
assisted procedures, are known and offer benefits to a patient for
example, limited incisional trauma, decreased pain, limited scars,
decreased hospitalization, and earlier return to a normal functional state.
To perform such procedures endoscopic imaging devices are employed. A
typical endoscopic imaging system includes a monitor, a light source, a
power source, a video processing unit, of the imaging system and an
endoscope. Conventionally, the various units are permanently or semi-
permanently installed within a cabinet, which occupies a substantial
portion of the operating room. In addition, the shifting and relocation of
the cabinet becomes a difficult task because of the size and weight.
[0003] Several techniques and devices have been employed to make the imaging
system compact and portable. One of such devices in particular adaptable
to evaluation of swallowing dysfunction comprises a housing having
various units such as the light source, endoscopic camera, video recording
device, video monitor, and power supply each unit being stored in several

3
compartments of the housing. Once the various units are stored in the
housing, the housing can be hand transferred to a patient's location.
However, the storing and setting up of the devices may be time
consuming and involve special skills. Another device attempts a reduction
in size of the housing by splitting the electronic circuit boards and
accommodating them along with the illumination control means in the
same housing. In addition, the thickness of the casing walls is reduced to
achieve lightweight and damper members are provided to ensure
protection of the electronic assembly from external forces. However,
additional shielding is needed for noise reduction, which makes the
maintenance more time consuming and difficult because of increased
number of components.
[0004] In light of the above discussion, Applicant's have recognized the
desirability of a compact and portable imaging device for endoscopic
application that overcomes one or more of the limitations of the prior art
devices, while maintaining one or more of their advantages. Further,
alternative cost effective solutions to achieve the desired outcome are
sought. Hence, the imaging device should be simple in design and be
portable, lightweight, economic, and easy to use.
OBJECTS OF THE INVENTION
[0005] It is therefore an object of the invention to propose a compact and
portable imaging device in an imaging system in particular for endosopic
application , which eliminates the disadvantages of the prior art.

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[0006] Another object of the invention is to propose a compact and portable
imaging device in an imaging system in particular for endosopic
application, which eliminates the requirement for additional shielding to
achieve noise reduction.
[0007]A still another object of the invention is to propose a compact and
portable imaging device in an imaging system in particular for endosopic
application, which is light weighted, simple, and easy to operate.
[0008]A further object of the invention is to propose a compact and portable
imaging device in an imaging system in particular for endosopic
application, which is portable, compact and cost-effective.
SUMMARY OF INVENTION
Accordingly there is provided a compact and portable imaging device in an
imaging system, in particular for endoscopic application, the system having an
endoscope insertable into the body of a patient for capturing video image from
the examination site, the device comprising a base unit accommodating an
illumination assembly a camera module converting reflected light in the
endoscope to video signals; and an electronic circuitry, the electronic circuitry
comprising a first electronic subassembly housed in the base unit for modulation
and isolation of the video signals; a second electronic subassembly housed in a
remote unit, for receiving electrical signal from the camera module for processing
and transmitting the processed electrical signals.

5
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
[0009] FIG. 1 illustrates an endoscopic imaging system having a portable and
compact imaging device, in accordance with the present invention;
[0010] FIG. 2 illustrates a functional block diagram of the base unit of the
portable and compact imaging device, in accordance with the present
invention;
[0011] Fig 3 is an exploded view of the base unit illustrating the packaging of
the various components with respect to the housing, in accordance with
an embodiment of the present invention;
[0012] FIG. 4 illustrates a stacked configuration of the first electronic
subassembly and the power supply module, in accordance with an
embodiment of the present invention;
[0013] FIG. 5a illustrates an assembly of the light source subassembly, the
illumination control means and the heat sink, in accordance with an
embodiment of the present invention;
[0014] FIG. 5b is an exploded view of an assembly of the illumination control
system and the heat sink, in accordance with an embodiment of the
present invention; and

6
[0015] FIG. 6 illustrates a remote unit, in accordance with an embodiment of the
present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016]Although the present invention will be described in conjunction with
several embodiments as depicted in the figures, a person skilled in the art
will easily recognize that numerous additional embodiments will be well
within the scope of the present invention, wherein the scope is defined by
the claims provided. Hence, the detailed description that follows is
intended merely to illustrate the present invention, and not intended to
limit the scope of the claimed invention in any way. Definitions of the
technical terminologies the used in the claims are intended to ensure that
the readers will not consider to limit the scope of these terminologies to
the specified preferred embodiments only, as described in this detailed
description. These definitions are given by way of example only, without
limitation.
[0017] The terms "electronic component", "electronic sub-assembly", "electronic
assembly" and "electrical component" are intended to refer to any
component or device that operates using electricity. Moreover, the term
'component' is meant to encompass any device that is a single component
device or a device that combines a number of components together. In
other words, it is intended that the terms be defined as broadly as would
be understood by those skilled in the art. The use of the term "electronic"
or "electrical" is not intended to be limiting in any manner, unless so

7
specified herein. Before delving into the specifics of the present invention, a
general overview is provided below.
[0018] The terms "fiber optics" and "fiber optic cable" as used herein are
intended to typically refer to flexible optical conductors comprising a
multiplicity of light conductive fibers, e.g. glass fibers, in the form of a
bundle or strand; generally, the bundle includes an adhesive, matrix or
the like for interconnection of the fibers, and a sheath, sleeve or the like is
arranged around the fiber bundle; the bundle ends are arranged in
planes, generally by grinding vertically to the axes of the fibers; when
used for illumination of a cavity, one of the planes is arranged near a light
source and referred to as "entrance plane" while the other plane is placed
near the site that is to be illuminated and is referred to as the "exit plane."
[0019] The term "light source" as used herein refers to a light source producing
light or a light beam. The light source can be a cold light source, wherein,
the light or the light beam contains only a negligible amount of heat
radiation, that is, only very little radiation in the infrared range of the
spectrum, if any. The light sources may also be chosen from other kinds
of light sources. Various light sources are known to those skilled in the
art, such as a halogen light source, xenon light source, metal halide bulb,
LED, tungsten filament bulb, arc light source and the like. Further, the light
source may sometimes include an integrated reflector for providing a focused
beam of light.

8
[0020] Once the scope of some of the critical terms has been defined, to get a
more complete understanding of the present invention, a detailed
description of the various embodiments of the present invention in
conjunction with the illustrations, is provided below.
[0021] Referring to FIG. 1, a portable and compact imaging device 110
adaptable to an imaging system 100 is illustrated, in accordance with the
present invention. The portable imaging device 110 includes a base unit
112, a remote unit 114, a connector 116, and a fiber optic cable 118. The
fiber optic cable 118 is connected to an endoscope 120. The endoscope
120 is coupled to the remote unit 114 by an optical coupler 150. The base
unit 112 is coupled to a display 130 by a video cable 160a, the display 130
showing the endoscopic video images. A recording means 140 is
connectable to the base unit 112 by a video cable 160b. The connector
116 connects the base unit 112 and the remote unit 114. In an
embodiment of the present invention, the connector 116 is a cable
connector. The cable connector 116 transmits video signals from the
remote unit 114 to the base unit 112 and transmits power from the base
unit 112 to the remote unit 114. In another embodiment of the invention,
the connector 116 is a wireless communication link between the remote
unit 114 and the base unit 112. Further, the remote unit 114 may be
battery powered. Further, the endoscopic imaging system 100 includes a
camera module. In an embodiment of the present invention, as illustrates
in FIG.l, the camera module is incorporated along with the remote unit
114 in the camera handle. Henceforth, unless mentioned otherwise, the
remote unit 114 includes the camera module.

9
[0022]The endoscopic imaging system 100 can be used for assisting minimally
invasive procedures, wherein the endoscope 120 is inserted into the body
of the patient and the video image captured from the site of examination
is displayed on the display 130. The portable imaging device 110 acts as a
video image capturing unit, a source for the light and a video processing
unit. Although the present invention describes the use of imaging device
110 in conjunction with surgical applications, various other possible use of
the imaging devices are known to those skilled in the art. For example,
such portable imaging devices have broad reaching application in the field
of computer inspection, customs inspection, plumbing, mining, automobile
mechanics, veterinary medicine, aviation, remote control devices, safety
equipment, monitoring devices, police investigations and in a variety of
other settings in which detailed inspection is desired. Further, the medical
use of the imaging device 110 includes therapeutic and diagnostic
medicine, inspection of body canals and openings, surgical applications
such as MIS, MAP, NOTES and the like, dental applications, phototherapy,
and others.
[0023]The portable imaging device 110, as illustrated in FIG.1, typically includes
a base unit 112, a remote unit 114, a connector 116, and a fiber optic
cable 118. Referring now to FIG. 2, a functional block diagram of the base
unit 112 of the portable imaging device 110 is provided, in accordance
with an embodiment of the present invention. The base unit 112 further
includes a light source subassembly 210, a cooling module 220, a power
supply 230, a first electronic subassembly 240, a housing 250, an
illumination control means 260, an indicator module 270, a fiber optic

10
receptacle 280, and a heat sink 290. The light source subassembly 210 provides
light for illuminating the site of examination. The light source subassembly 210
includes a light source 212, a reflector 214, and a light source holder 216. The
light source 212 and the reflector 214 are attached to the light source holder
216. The heat sink 290 is coupled to the light source subassembly 210. The heet
sink 290 is provided to dissipate the heat generated by the light source assembly
210. The heat sink assembly 290 is also attached to the fiber optic receptacle
280. The fiber optic receptacle 280 acts as an optic port and provides a slot to
align the receptor end of the fiber optic cable 118 (as shown in FIG. 1) with the
beam of light generated by the light source subassembly 210. The cooling
module 220 is placed adjacent to the heat sink 290 such that cooling module 220
blows cool air on the heat sink 290, the light source subassembly 210 and an
illumination control means 260. The cooling module 220 draws the cooling air
such that air is sucked from the areas surrounding the power supply module 230
and the first electronic subassembly 240. Thus, the cooling module 220 controls
the rise in temperature of the base unit 112 by dissipating the heat generated by
the light source subassembly 210, the power supply module 230 and the first
electronic subassembly 240. The power supply module 230 powers the cooling
module 220, the light source subassembly 210, the first electronic subassembly
240, and the remote unit 114 (shown in Fig. 1). In an embodiment of the
present invention, the power supply module 230 has two major supply modules,
a low voltage module 232 and a high voltage module 234. The low voltage 232
module is mainly made up of transformer and the high voltage module 234 is
mainly made up of ballast. The high voltage module 234 provides power supply
to the Light source subassembly 210 and the cooling module 220. The low
voltage module 232 provides power supply to the first electronic subassembly

11
240 and the remote unit 114, wherein the remote unit 114 includes the
camera module. The first electronic subassembly 240 modulates, controls
and isolates the video signals received from the remote unit 114, the
video signal received via the connector 116. In an embodiment of the
present invention, the first electronic subassembly 240 includes a timer
circuit 242 and a video isolation circuit 244. The timer circuit 242 is
attached to the indicator module 270. The first electronic subassembly
240 also includes output ports 246 where the display 130 and the
recording device 140 can be connected. The display 130 is used to view
the video images from the workspace. The housing 250 encloses the
various components of the base unit 112 and provides provisions for
effective functioning of the cooling module 220 as discussed in one of the
co-pending application, the co-pending application has been provided as a
reference. The illumination control means 260 controls the illumination
intensity of light that is supplied at the entrance plane of the fiber optic
cable 118. The detail of the illumination control system 260 has been
discussed in details in another co-pending application provided as
reference.
[0024]In the light of the above description in FIG. 1 and FIG.2, the endoscopic
imaging system 100 comprises of two essential flows. The first being the
flow of light for illuminating from the light source subassembly 210 to the
workspace to be visualized. The second being the flow of the video signals
from the workspace to the display 130. The following paragraphs explain
these flows and the associated system modules.

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[0025]The light originating from the light source 212 is transformed into a
focused beam of light by the reflector 214. The focused beam of light
passes through the illumination control means 260, which is located
between the light source 212 and the fiber optic receptacle 280. The
illumination control means 260 controls the intensity of light beam that
passes through the fiber optic receptacle 280. The light beam is
thereafter, transmitted through the fiber optic cable 118 to the endoscope
120. The light beam passes through the endoscope 120, and illuminates
the workspace to be visualized.
[0026]Once the site is illuminated, the object reflects the light and the reflected
light passes through the objective lens of the endoscope 120 and further
transmitted to the remote unit 114. The camera module in the remote
unit 114 converts the reflected light to video signal by an in-built image-
processing unit. Thereafter, the video signal is passed to the first
electronic subassembly 240 through the connector 116. The connector
116 is attached to the video isolation circuit 244 by a connection port 24P.
The video signals are modulated and isolated by the video isolation circuit
244. The video isolation circuit 244 also includes video output ports 246.
The output ports 246 provide the video signal to the display 130 and
recording device 140 through the video connectors 160a and 160b. The
display 130 and recording device 140 are used to view and/or record the
video images from the workspace.

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[0027]The following paragraphs describes in details the various sub assemblies,
components, and modules of the portable imaging device 110. The
detailed description would include the constitution level details and the
functional details of the modules/sub-assemblies. In addition, the detailed
description ascertains that the portability and compactness are achieved
by the novel arrangement and placement of the various components,
modules and sub-assemblies.
[0028] Fig 3 is an exploded view of the base unit 112 illustrating the packaging
of the various components with respect to the housing 250, in accordance
with an embodiment of the present invention. The housing 250 is a four-
piece assembly and comprises a front panel 310, a top cover 320, a
bottom plate 330, and a middle panel 340. The front panel 310 is fitted on
the bottom plate 330 with a supporting plate 318. The supporting plate
318 is also attached to the middle panel 340 at an attachment member
342. A fastening member attaches the supporting plate 318 to the bottom
plate 330 and the middle panel 340. The top cover 320 is fitted on the
middle panel 340 and tightened by the knurl screws 322. The knurl screws
322 can be released by hand. Hence, the removal of the top cover 320
during maintenance or light source 212 replacement is tooless. The
housing 250 can be made of metal, alloy, carbon fiber, heat resistant
plastic, glass, composites, ceramic, and the like. The housing 250 provides
protection to the inside components. The housing 250 also helps in
dissipating the heat produced by the components inside the housing 250
and in reducing the EMI / EMC effect on first electronic subassembly 240
and power supply module 230 from electromagnetic interference caused

14
by other electronic & electrical equipments in the surrounding environment of
the light source 212 during the functioning of the imaging device 110.
[0029]The front panel 310 provides an attachment arrangement for various
components such as the indicator module 270 and the indicator PCB 314,
the front panel on/off switch 316 and the connection port 248. The front
panel 310 provides an opening 312 for fitting the fiber optic receptacle
280. The front panel 310 also provides a window 313 for accommodating
a knob of the illumination control means 260. An EMI filter 344 is
mounted on rear of the middle panel 340. The EMI filter 344 is electrically
connected to the Mains On/off Switch. This EMI filter 344 is used to
suppress common mode noises and differential mode noises. Generally,
these filters eliminate electromagnetic interferences created by the
equipment and the component itself. A safety micro-switch 346 is also
installed in a frame mounted on the middle panel 340. This switch 346 is
used to shut off the power supply to the light source when the top cover
320 is removed.
[0030]The bottom plate 330 is used for fitting various modules of the base unit
112 such as the light source subassembly 210, the cooling module 220,
the illumination control means 260, and the heat sink 290. The first
electronic subassembly 240 and the power supply module 230 comprising
the high voltage module 234 and the low voltage module 232 are
arranged in a stacked configuration on same side of the cooling module
220. The stacked configuration has been explained in detail in conjunction
with FIG. 4.

15
[0031]FIG. 4 illustrates the stacked configuration of the first electronic
subassembly 240 and the power supply module 230, in accordance with
an embodiment of the present invention. The stacked configuration
conserves space in the housing 250. As stated above, in an embodiment
of the present invention, the power supply 230 has two major supply
modules, a low voltage module 232 and a high voltage module 234. The
high voltage module 234 comprises mainly of a ballast therefore it is
heavy and generates a high amount of heat. Therefore, the high voltage
module 234 is placed in the bottom of the stacked configuration. The
high voltage module 234 is covered with a ballast casing 402. Functionally
the ballast casing 402 provides an EMI/EMC shield, a protective covering
and dissipates the heat produced by the high voltage module 234. The
low voltage module 232 and the first electronic subassembly 240 is placed
above the high voltage module 234 such that they are fitted on top of the
ballast casing 402. A PCB chassis 404 covers the first electronic
subassembly 240 and it is fitted on the top of the ballast casing 40k.
Functionally the PCB chassis 404 provides an EMI/EMC shield, a protective
covering and dissipates the heat produced by the first electronic
subassembly 240. The ballast casing 402 and the PCB chassis 404 has
numerous openings 406. The openings 406 are created to facilitate the
flow of air over the first electronic subassembly 240 and the power supply
module 230. Also the openings 406 reduce the overall weight of the light
source subassy 210. The embodiment of the present invention illustrates
the openings 406 in the circular and rectangular configuration, however,
numerous shapes other and their variations may occur to those skilled in
the art, such as, triangular, polygonal, square and the like.

16
[0032]FIG. 5a in conjunction with FIG. 5b describes the assembly of the light
source subassembly 210, the illumination control means 260 and the heat
sink 290. FIG. 5a illustrates the assembly of the light source subassembly
210, the illumination control means 260 and the heat sink 290, in
accordance with an embodiment of the present invention. FIG. 5b is an
exploded view of the assembly of the illumination control means 260 and
the heat sink 290, in accordance with an embodiment of the present
invention.
[0033]The heat sink 290 includes a front flange 502, a rear flange 504, and a
base plate 506. The base plate 506 connects the front flange 502 and the
rear flange 504 such that they are placed at a fixed distance from each
other and are parallel to each other. The heat sink 290 is fixed on a C
plate 508 by fastening members 510. The C plate 508 is fixed to the
bottom plate 330, thereby stabilizing the complete heat sink 290. The
fastening members 510 are each placed in atleast one first slot 512 having
a multi-step configuration wherein the profile of the slot decreases
towards the C plate 508. This arrangement provides a leeway for fixing
the heat sink 290 according to the desired optical alignment for different
types of light source subassemblies 210. The heat sink 290 can be made
of aluminum, copper, alloys, steel and the like.
[0034]The rear flange 504 has an extension member 514 for sliding, holding,
aligning and for removably fitting the light source subassembly 210 on the
heat sink 290. Extension member 514 is configured in such a manner that
it is congruent with the light source holder 216. A hand operated knurl

17
screw 516 is provided to removably fit the light source subassembly 210 on the
rear flange 504. A second slot 518 is provided in the rear flange 504. The
second slot 518 extending through the extension member 514. The second slot
518 provides a tolerance to accommodate thermal expansion of the light source
holder 216 as well as the rear flange 504 and the extension member 514.
Further, the second slot 518 accommodates the wiring that supply electric power
to the light source 212.
[0035]The front flange 502 has fins 520 to increase the surface area for
dissipating the heat generated by the light source subassembly 210. The
front flange 502 also has a cutout section 522 to fit the illumination
control means 260. The front flange 502 provides a stub 524 for
accommodating the fiber optic receptacle 280. The fiber optic receptacle
280 is snuggly fitted on the stub with a ring member 526 in between. The
ring member 526 fits inside the fiber optic receptacle 280 and has metal
balls inserted in the body. The arrangement creates a snap fit
arrangement for the fiber optic cable 118 when inserted in the fiber optic
receptacle 280. Further, the ring member 526 and ball arrangement
ensures proper alignment of the entrance plane of fiber optic cable 118
and the beam of light coming from light source 212. In addition, the
illumination control means 260 is attached to the cut-out section 522 on
the front flange 502. Lastly, a thermal protection plate 528 covers the
heat sink 290 along with the light source subassembly 210. The thermal
protection plate 528 is fitted on the heat sink 290 by means of a hand
operated knurl screws 530. The thermal protection plate creates a barrier
between the light source 212 and the top cover 320, blocking the direct

18
transmission of heat to the top cover 320. The thermal protection plate also
helps in dissipating the heat generated by the light source 212.
[0036]In the embodiments of the present invention described above, the heat
sink 290 is a single unit. However, in various other embodiments of the
present invention, the heat sink be made up of one or more components.
For example, in an embodiment of the present invention, the front flange
502 and the rear flange 504 can be arranged such that they have a
flexibility of changing the distance as well as the angle between them.
This can be achieved by an arrangement for sliding the front flange 502
and the rear flange 504 on the base plate 506 with a fixing arrangement
at a desired distance and angle. Changing the distance and the angle
between the front flange 502 and rear flange 504 provides a flexibility to
accommodate different types of light source subassembly.
[0037]Referring now to FIG. 6, the remote unit 114 is illustrated, in accordance
with an embodiment of the present invention. The remote unit 114
includes a top cover 610, a bottom cover 620, a front cover 630, a camera
module 640, a white balance circuit 650, a ball socket means 660, a
switch interface 670, and assembly features 680. As shown in the FIG. 6,
the remote unit is the camera handle, which is coupled to the endoscope
120 by a optical coupler 150. The top cover 610, the bottom cover 620,
and the front cover 630 forms an enclosed space for housing the camera
module 640 and the white balance circuit 650. The top cover 610 includes
a slot 612 and some of the assembly features 680. The slot 612 is used to
affix the switch interface 670 to the top cover 610. As shown in Figure 6,

19
the slot 612 also includes circular holes so that the switch interface 670 is in
contact with the white balance circuit 650. The assembly features 6 in the top
cover 610 also provide support for the white balance circuit 650 to be placed in
an inclined fashion with respect to the top cover 610. Similarly, the bottom
cover 620 also provides a first assembly features 614 for coupling the top cover
610 to the bottom cover 620. In addition, the first assembly features 614 in the
bottom plate 620 provide support to the white balance circuit 650. Further, a
second assembly features 614 are provided in the bottom cover 620 to
accommodate the ball socket means 660. The ball and socket means 660 is
provided to support the end of the connector 116 coupled to the white board
circuit 650 and the camera module 640. In an embodiment of the present
invention, the ball and socket arrangement 660 includes a silicon ball 662 housed
in a polypropylene socket 664. The ball and socket arrangement provides
flexibility to the connector 116 and increases the maneuverability of the remote
unit 114 integrated with the camera handle. Hence reducing the damage to the
connector 116. In addition, the ball and socket means 660 is particularly useful
for medical applications wherein the instrument has to cleaned and sterilized, as
the ball and socket arrangement 660 ensures proper sealing of the camera
handle at the entry point of the connector 116.
[0038]Moving on to the white balance circuit 650 that is positioned between the
top cover 610 and the bottom cover 620. The white balance circuit 650
provides the user with capability to compensate for the differences in
color temperature of the light from the light source 212 and the
surrounding light and further lock a desired color setting. The white
balance circuit 650 includes a micro-switch 652 and LEDs 654. The white

20
balance circuit 650 is coupled to the camera module 640 where the parameters
corresponding to the desired color setting are stored. When the micro-switch
652 is pressed the color compensation is activated, consequently when the
desired color setting are achieved the micro-switch 652 is pressed again, and the
desired color settings are locked. In an embodiment of the present invention,
one of the LEDs 654 turns green indicating a white balance lock. The other LED
654 is to indicate the power supply to the remote unit 114. The LED 654 are
coupled to the slot 612 in the top cover 610.
[0039]As illustrated above, the white balance circuit 650 is incorporated in the
remote unit 114. However, various other embodiments may be obvious to
those skilled in the art. For example, in an embodiment of the present
invention, the white balance circuit 650 may be incorporated in the base
unit 112. In another embodiment of the present invention, there may be
two white balance circuits 650 one provided in the base unit 112 and
another provided in the remote unit 114.
[0040]The front cover 630 is provided to protect and house the camera module
640. Also, the front cover 630 includes provision for coupling the front
cover 630 with the optical coupler 150. Further, appropriate sealing is
provided between the window 632 in the front cover 630 and the camera
module 640. The camera module 640 includes a camera chip 642 and an
image processing circuit 644. In an embodiment of the present invention,
the camera chip 642 is a 1/3-inch CCD chip which senses the light coming
from the endoscope 120, and converts the light to an electric signal that is
sent to the image processing circuit 644. In various other embodiment of

21
the present invention, the camera chip 642 can be a CMOS chip, a V½ inch CCD
chip, a ¼ inch CCD chip, a 2/3 inch CCD chip, 3CCD sensor, and the like.
Further, the camera chip may be sensitive to different kind of light spectrum,
such as infrared, ultraviolet, visible light, fluorescence spectrum, or a
combination thereof. The image processing circuit 644 receives the electric signal
from the camera chip and processes the signal. The processed signal is then
passed to the base unit 112 via the connector 116. In an embodiment of the
present invention, the processing of the signal includes amplification of the
signal, filtering out of noise from the signal, analog to digital conversion,
frequency filtering, image corrections, phase modulation, signal amplitude and
frequency modulation, and the like. In addition, in an embodiment of the present
invention, the image processing circuit 644 can be a programmable chip, wherein
the various parameters relating to signal processing and camera chip can be
adjusted.
[0041]As illustrated in the various embodiments above, the remote unit 114 is
incorporated as the camera handle. However, various other embodiments
of the remote unit 114 may be obvious to those skilled in the art. For
example, in an embodiment of the present invention, the remote unit 114
may be a compact module comprising the image processing circuit 644
and the white balance circuit 650. The image processing circuit 644 and
the white balance circuit 650 are together termed as second electronic
subassembly. The remote unit 114 is connected to the camera chip 642
and the base unit 112 via connectors to carry electrical power and data
signals. In addition, remote unit 114 may be integrated with the
connector. In another embodiment of the present invention, the remote

22
unit 114 may be realeasably connected with the camera chip 642 and the base
unit 114 via the connectors.
[0042]In the light of the above description, the portability and compactness of
the portable imaging device 110 is achieved by a novel configuration and
arrangement of the various components and modules. The paragraphs
below draw attention to some of the aspects of the present invention that
contribute to the compactness and portability.
[0043]The light source subassembly and the heat sink housed in the base unit
realizes a modular, compact, and multifunctional arrangement. Further,
the illumination control unit is integrated with the heat sink. The light
source and the reflector are integrated such that a focused beam of light
is provided at the optic port, hence, eliminating the need for a lens system
to focus the light. The heat sink also functions as a mounting unit for the
light source. Additionally the heat sink accommodates the alignment of
the light source, the illumination control system and the optic port. The
heat sink also serves as the mounting for the illumination control unit.
Hence, the heat sink integrates and aligns the various components of the
light source subassembly. Therefore, enabling the light source
subassembly to be housed in the base unit along with the various other
modules and sub-assemblies. In addition, since the light source is
integrated with a reflector most of the heat generated is localized in front
of the light source, hence, fins are provided only at the front section of
the heat sink, further allowing reduction in the size and weight. Further,
to reduce the weight of the complete assembly the heat sink, illumination

23
control system, mounting bracket, are made of lightweight material such as
aluminum and aluminum alloys.
The present invention provides a stacked configuration of the first electronic
subassembly and the power module in the base unit. In an embodiment of the
present invention, the electronic subassembly includes video isolation circuit
board, and timer circuit. The power supply module includes the ballast, and the
transformer. The stacked up arrangement of the various component allows for
ample space for other modules to be fitted in. In addition, the mounting chassis
and casing for the PCB and ballast also enable efficient cooling of the electronic
circuitry. Further, in an embodiment of the present invention, the ballast is at the
bottom of the stack. Hence, preventing a direct contact with the high voltage
components during maintenance and bulb replacement, thus realizing safety.
[0044]The portability and compactness of the portable imaging device is also
realized by accommodating the electronic circuits partially or completely in
the remote unit. Accommodating the electronic circuitry in the remote unit
and the base unit eliminates the need for an additional module for video
signal and image processing. In addition, the electronic circuitry
accommodated in the remote unit does not require noise-protection
circuits, as the remote unit is located far from the heavy electronic
devices.

24
[0045]Apart from the portability and compactness, the embodiments of the
present invention provide various other advantages such as ease of
handling, safety, and easy maintenance. The ease of maintenance of the
base unit is achieved by providing hand-releasable fastening means. The
said fastening means are provided for coupling the top cover of the base
unit to the middle panel, for coupling the thermal protection plate with the
heat sink, for holding the bulb holder in the rear flange of the heat sink,
for coupling the fiber optic receptacle to the stub of the heat sink's front
flange. In addition, various safety features are provided in the base unit,
for example, a video isolation circuit is provided to protect the electronic
circuitry from back surge coming from the TV, monitor, recording device.
A safety micro-switch is provided to shut down the bulb as soon as the
top cover is lifted. As explained above, the ballast containing high voltage
elements is placed at the bottom of the stack for safety. Hence, the
portable imaging device achieves various other advantages as well apart
from portability and compactness.
[0046]While the present invention has been illustrated by description of several
embodiments, it is not the intention of the applicant to restrict or limit the
scope of the appended claims to such detail. Numerous other variations,
changes, and substitutions will occur to those skilled in the art without
departing from the scope of the invention.

25
WE CLAIM
1. A compact and portable imaging device (110) in an imaging system
(100), in particular for endoscopic application, the system having
an endoscope (120) insertable into the body of a patient for
capturing video image from the examination site, the devica
comprising:
- a base unit (112) accommodating an illumination assembly (210);
- a camera module, converting reflected light in the endoscope (120)
to video signals; and
- electronic circuitry, the electronic circuitry comprising
i. a first electronic subassembly (240) housed in the base unit
(112) for modulation and isolation of the video signals;
ii. a second electronic subassembly housed in a remote unit
(114), for receiving electrical signal from the camera module
for processing and transmitting the processed electrical
signals.
2. The device as claimed in claim 1, wherein the illumination assembly
comprising:

26
- a light source mounting (210) releasably coupled to the bottom of
the base unit (112);
- a light source (212) having a reflector (214), the light source (212)
adjustably coupled to a mounting socket (216) on the mounting,
wherein the light source (212) is moveable for adjusting the focal
point of the light;
- a fiber optic port (280) integral to the mounting and located
concentrically to the mounting socket (216); and
- a fiber optic receptacle (280) for receiving the connector (116) for
a fiber optic cable (118), wherein the socket (216) is aligned with
the fiber optic inlet port (280) and is coupled to the mounting
(210).

3. The device as claimed in claim 1, comprising a ballast circuit (234) for
supplying power to the light source (212).
4. The device as claimed in claim 3, wherein the ballast (234) and the first
electronic subassembly (240) are housed in the base unit (112) in a
stacked configuration.
5. The device as claimed in claim 1, wherein the first electronic subassembly
(240) comprising:

27
- a video isolation circuit (244);
- a timer circuit (242); and
- a power supply module (230).
6. The device as claimed in claim 1, wherein the second electronic
subassembly comprising:
- an image processing circuit (644); and
- a white balance circuit (650).

7. The device as claimed in claim 1, wherein the remote unit (114) and the
camera module are incorporated in a camera-handle.
8. The device as claimed in claim 1, comprising a connector (116), the
connector (116) transmitting signal from the remote unit (114) to the
base unit (112) and transmitting power from the base unit (112) to the
remote unit (114).
9. The device as claimed in claim 1, comprising a wireless communication
link between the remote unit (114) and the base unit (112).
10.The device as claimed in claim 9, wherein the remote unit (114) is batter/
powered.

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11. A compact and portable imaging device in an imaging system, in particular
for endoscopic application as substantially described herein and illustrated
with reference to the accompanying drawing.

This invention relates to a compact and portable imaging device (110) in an imaging system (100), in particular for endoscopic application, the system having an endoscope (120) insertable into the body of a patient for capturing video
image from the examination site, the device comprising a base unit (112) accommodating an illumination assembly (210); a camera module converting reflected light in the endoscope (120) to video signals; and electronic circuitry,
the electronic circuitry comprising a first electronic subassembly (240) housed in
the base unit (112) for modulation and isolation of the video signals; a second electronic subassembly housed in a remote unit (114), for receiving electrical signal from the camera module for processing and transmitting the processed electrical signals.