JPH01222579A - Image pickup device - Google Patents

Abstract

PURPOSE:To lower the heat dissipation to a solid-state image pickup element by using two packing material with different heat conductivity and varying the quantity of heat diffusion from a heat source depending on the direction. CONSTITUTION:A packing material 14 with a low heat conductivity is packed toward the image pickup element 13 from an electronic circuit 16 being a heat source around the solid-state image pickup element 13 and a packing material 17 with a high heat conductivity is packed toward a processor or a transmission cable 18 from the heat source 16. Thus, the heat generated in a housing giving electrically adverse effect onto the solid-state image pickup element 13 is not transmitted to the solid-state image pickup element 13 at most. Then the heating of the solid-state image pickup element 13 due to resident heat in the housing generated in the circuit board is avoided and the production of the deteriorated S/N due to the increase in dark current or the deterioration in the picture quality due to increase in the thermal noise is avoided.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention provides an image carrier that has a solid-state element image as an imaging means and can prevent heat generated by an electronic circuit from being transmitted to the solid-state element side. Regarding equipment.

[Problems to be solved by conventional techniques and inventions] In recent years, I
An endoscope that allows you to diagnose and examine organs inside the body cavity by inserting the O-length insertion part into the body cavity!
i (scope or fiberscope) has become widely used.

In addition, boilers, i
It is used for observing and inspecting objects inside pipes, equipment, etc. of ts, chemical plants, etc.

Furthermore, various types of electronic scopes are also used that use a solid-state image probe such as a charge-coupled device (COD) as an imaging means. This electronic scope has advantages such as higher resolution than a fiber scope, ease of recording and reproducing images, and ease of image enlargement and image processing for comparison on two screens.

By the way, the above-mentioned electronic software is disclosed in US Pat. No. 44, for example.
As disclosed in No. 91865, there is a method in which a solid-state image sensor is provided on a substrate, a signal line connected to the actual surface of the U board is fixed with resin, etc., and the whole is sealed in a housing. . In this case, the main purpose of keeping the inside of the housing tightly sealed is to prevent looseness due to moisture intrusion and to reinforce the strength of the housing.

In addition to the above, there is also a solid-state image sensor inside the housing.
In some cases, a board on which a driving circuit for driving the solid-state imaging element and an output buffer for outputting a video signal converted by the solid-state imaging element are mounted is installed inside the housing.

In this case, the drive circuit handles a high frequency, and
When driving a high-capacity element such as a COD as a solid-state image sensor, the amount of heat generated is large because it needs to be driven at particularly low impedance. In addition, especially in imaging devices where the head unit and the processor unit that processes video signals are remotely connected via a cable, an output buffer for cable transmission is required to perform low impedance conversion, that is, current amplification. It has a large amount of heat. This amount of heat generated is often larger than the amount of heat generated by solid-image cells. In this case, if the solid-state image sensor and the substrate are filled with resin or the like, the heat generated by the substrate will be trapped inside the housing, heating the solid-state FD image carrier.
As a result, there is a risk of deterioration in image quality such as a decrease in S/N ratio due to an increase in dark current and an increase in heat-generated noise.

[Object of the Invention] The present invention has been made in view of the above-mentioned points, and is an object of the present invention to provide a transport system that can minimize the amount of heat generated within the housing that adversely affects the solid-state X-image sensor from being transmitted to the solid-state image sensor. The purpose is to provide an imaging device.

[Means for Solving the Problems] The m-image device of the present invention includes a solid-state imaging device as an imaging means for imaging a subject, an electronic circuit connected to the solid-state imaging device, and a solid-state 1a imaging device. a first component occupying a space adjacent at least a portion of the periphery;
occupies the periphery of the electronic circuit adjacent to the component of the first
and a second component having lower heat transfer and conductivity than the component.

[Operation 1] In the present invention, a filler with a lower thermal conductivity is filled on the side closer to the image sensor than the heat source, and a filler with a higher thermal conductivity is filled on the side closer to the processor or the transmission cable than the heat source.

[Example J 1 to 3 show a first embodiment of the present invention. In FIG. 1, the concept of the imaging device e1 will be explained.

A first filling member 14 as a first component is provided behind a solid-state imaging device (hereinafter abbreviated as COD) 13 that can image a subject and on the side opposite to the decoy image surface. A second filling member 17 as a second component that fills the periphery of the electronic circuit 16 electrically connected to the CCD 13 is provided adjacent to the rear of the first filling portion 014. .

Further behind this second filling part 4417, an electronic circuit 1
A processor section or transmission cable 18 is provided which is electrically connected to the processor section 6.

Here, if the thermal conductivity of the first filling member 14 is α and the thermal conductivity of the second filling member 17 is β, then α × β, and the electronic circuit 16 in the second filling member 17 This makes it more difficult for the generated heat to be transferred to the CCD 13 and more easily transferred to the processor section or the transmission cable 18 side.

A specific example of this embodiment will be explained with reference to FIGS. 2 and 3.

In FIG. 3, a camera head 2 incorporating an imaging device 1 is shown.
+! to the eyepiece 4 of the fiber scope 3! 7.It is designed to be removable. This fiber scope 3 has a flexible insertion section 5 made of III-type at the front.
A large diameter operating section 6 is connected to the rear end of the insertion section 5 . A universal cord 8 extends from the side of the operating section 6 and is capable of transmitting illumination light and has a light source connector 7 at its tip that can be connected to a light source device (not shown).

A signal cable 9 through which video signals are transmitted extends from the rear end of the camera head 2, and a signal connector 11 installed at the rear end of the signal cable 9 connects to a signal processing device 12.
It is designed to be connected to. This signal processing device 12
is adapted to send a video signal to a monitor (not shown).

The camera head 2 is formed of a rigid camera head body 19, and a connecting portion 21 is provided at the front portion of the camera head body 19 to which the eyepiece portion 4 can be detachably connected.
is provided. An objective lens system 22 whose optical axis coincides with an eyepiece system (not shown) of the eyepiece section 4 is positioned and fixed behind the connection section 21. At the imaging position of this objective lens system 22, there is a camera head body 19.
The image surface of the CCD 13, which is arranged so as not to come into direct contact with the object, is positioned so as to cover the image surface of the CCD 13. A drive signal for driving this CCD 13 and a CC
A lead portion 23 protrudes rearward through which a video signal photoelectrically converted by D13 can be input/output. This lead part 2
3 is connected to a board 24 on which an electronic circuit 16 such as a drive circuit for the CCD 13 or an output circuit for the CCD 13 is mounted and wired, which is disposed at right angles to the CCD 13 at the rear. The material of this substrate is alumina ceramics with a thermal conductivity of 25.2 kcal/ih-'C or a thermal conductivity of 0.14 kcal/m.
Epoxy resin etc. with a temperature of h/°C are used.

A signal line 26 inserted through the signal cable 9 is connected to the rear end of this board 24, and the video signal a3 and CC
It is connected to the signal processing device 12 so as to be able to transmit drive signals and the like for the D13.

The front part of the substrate 24 in the camera head main body 19 and the CCD
13 against 11! The periphery on the image plane side is filled with a first filling member 14 having low thermal conductivity. This first filling member 1
The material of 4 has a thermal conductivity of 0゜022kCal/II-
Air at h-'C, 0.01 kcal/m-h・℃
Styrofoam, etc. Further, a second filling member 17 having a higher thermal conductivity than the first filling member 14 is filled in the contact portion of the substrate 24 and around the electronic circuit 16 mounted on the substrate 24 . The materials to be collected for this second filling member 14 include heat dissipating silicon with a thermal conductivity of 0°9 kcal/m-h-'C, cement and low-melting point glass with a thermal conductivity of 0.7 kcal/m-h C, and 25.2 kcal. /m −h ・℃
ceramics, etc.

Note that the substrate 24 may be a flexible substrate made of resin or the like.

The operation of the 11ii image device 1 configured as described above will be explained.

A camera head 2 connected to an eyepiece 4 of a fiber scope 3 receives a subject image on a fil II surface of a CCD 13 . On the other hand, a drive signal is input from the signal processing device 12 to the drive circuit of the electronic circuit 16, the voltage level is adjusted, and the CC
Applied to D13. In the CCD 13, a photoelectrically converted video signal is read out using this drive signal, amplified by an output circuit of an electronic circuit 16, and sent to the signal processing device 12.

The signal processing device 12 converts the video signal into a video signal, outputs it to a monitor (not shown), and displays an image on the screen of this monitor.

Since current amplification is performed in the electronic circuit 16, a large amount of heat is generated, and the amount of heat generated is diffused within the second filling member 17. The amount of heat generated is transmitted to the camera head main body 19, the first filling member 14, and the signal cable 9 adjacent to the second filling member 17. Since the thermal conductivity is low, it takes time to transfer the amount of generated heat, and most of the generated heat M is transferred to the camera head main body 19 and the signal cable 9, and is radiated from the signal cable 9. The CCD 13 is not in contact with the camera head body 19, and a small amount of heat is transmitted only through the lead portion 23.

Since the heat generated by the electronic circuit 16 is diffused in a directional manner as in this embodiment, the heat generated by the electronic circuit 16 is
Den 3 on CD13! ! It is possible to prevent this as much as possible, prevent an increase in dark current caused by heating the CCD 13, and increase the S/N ratio.

Furthermore, as another effect, the electronic circuit 16 and each electrical contact can be moisture-proofed and hermetically sealed, and the strength of the entire camera head can be improved.

FIG. 4 shows a second embodiment of the invention.

In this embodiment, the substrate 24 is provided so as to face the opposite side of the CCD 13. Note that the configuration and operation different from the first embodiment will be described.

A rigid camera head main body 19 constituting the camera head 2 incorporating the image carrier 1 is provided with a connecting portion 21 in the front portion that can be detachably connected to the eyepiece portion 4. An objective lens system 22 whose optical axis coincides with an eyepiece system (not shown) of the eyepiece section 4 is positioned and fixed behind the connection section 21. At the imaging position of the objective lens system 22, the Md image plane of the CCD 13, which is disposed so as not to be in direct contact with the camera head main body 19, is located. On the opposite image plane side of this CCD 13, there is a lead section 2 that can send out a video signal photoelectrically converted by this CCD 13.
3 is protruding backwards. This lead portion 23 is electrically connected to the upper part of a substrate 24 disposed further rearward so as to face the anti-transfer image plane of the CCD 13. This board 2
4 are laminated with substrates 28, 28, . A signal line 26 inserted through the signal cable 9 is connected to this board 28.

The upper part of the board 24 inside the camera head body 19 and the CCD 13
The first filling member 14 with low thermal conductivity is located around the anti-transfer image plane.
The area around the substrate 28 and the electronic circuit 16 at the bottom of the substrate 24 is filled with a second filling member 1 having high thermal conductivity.
It is filled with 7.

Generally, the material used for the substrate is ceramics,
Ceramics have high thermal conductivity and easily transfer generated heat. In this case, the heat transfer can be delayed by laminating the substrates 28 as in this embodiment. Furthermore, the material of the substrate 28 may be partially changed.

The other functions and effects of the configuration 9 are similar to those of the first embodiment.

FIG. 5 shows a third embodiment of the invention.

In this embodiment, the substrate 24 faces the anti-transfer image plane of the CCD 13.

An image carrying plane formed on the CCD 13 is located at the image forming position of the objective lens system 22 disposed inside the front part of the camera head body 19. A lead portion 23 protrudes rearward on the opposite image plane of the CCD 13. This lead part 23 is a CCD
The upper part of the substrate 24, which is disposed facing the anti-image surface of 13, is electrically connected. An electronic circuit 16 is mounted on the bottom of the board 24, and a signal line 26 inserted through the signal cable 9 is electrically connected to the bottom end of the board 24.

Inside the camera head body 19, the anti-transfer image plane of the CCD 13 and the periphery of the substrate 24 are filled with a first filling portion 4114 having low thermal conductivity. The area around the electronic circuit 16 at the bottom of the substrate 24 is filled with a second filling part 4417 having high thermal conductivity.

The operation and effects of the first configuration are the same as those of the first embodiment.

FIG. 6 does not show the fourth embodiment of the invention.

The camera head 2 of this embodiment is composed of a camera head base member 29 and a camera head tip member 31, and a constant distance is maintained between the camera head base member 29 and the camera head tip member 31. .

At the distal end of the camera head distal end member 31, a connection section 21 is provided which is detachably connected to the eyepiece section 4 of the fiber scope 3. An objective lens system 22 whose optical axis coincides with an eyepiece system (not shown) provided in the eyepiece section 4 is provided behind the connection section 21 . An image carrying plane formed on the CCD 13 is located at the image forming position of the objective lens system 22. The lead portion 2 is on the anti-transfer image plane of this CCD 13.
3 is provided so as to protrude rearward.

The lead part 23 is a substrate 24 arranged at right angles to the CCD 13.
electrically connected to the front of the The anti-transfer image plane of the CCD 13, the lead portion 23, and the front portion of the substrate 24 are filled with a first filling member 14 having low thermal conductivity. Substrate 24
The rear part of the camera head protrudes to the rear of the camera head tip member 31.

An electronic circuit 16 is mounted on the rear of the protruding board 24, and a signal cable 9 is further mounted on the rear end of the board 24.
A signal line 26 inserted therethrough is electrically connected.

The rear part of the substrate 24, the electronic circuit 16, and the tip of the signal line 26 are surrounded by the camera head base member 29, and the periphery is filled with a second filling member 17 having high thermal conductivity. A third filling member 32 whose thermal conductivity is higher than that of the first filling member and lower than that of the second filling member 17 is provided between the first filling member 14 and the second filling member 17 so that the camera head It is filled so as to keep the distance between the base member 29 and the camera head tip member 31 constant.

Note that the thermal conductivity of the third filling portion 4432 may be lower than that of the first filling member 14 and may be lower than that of the second filling member 17.

By configuring as in this example, even if the camera head is made of a material with high thermal conductivity, CGI)13
It is possible to prevent heat from being transferred to the distal end side of the camera head that houses the COD 13, and it is possible to prevent the COD 13 from being indirectly heated by the camera head.

The other functions and effects of the configuration 9 are similar to those of the first embodiment.

7 and 8 show a fifth embodiment of the invention.

In this embodiment, an imaging device 1 is built into the distal end of an endoscope.

In FIG. 7, the endoscope bag ff36 is connected to the endoscope 1137,
A light source unit that supplies illumination light to the endoscope 37 and the endoscope 37
The control device 38 includes a signal processing section that processes image signals output from the control device 38, and a monitor 39 that displays the video signal output from the control device 38 on a screen.

The said family gift VT37 has an elongated insertion part 41 and this insertion part 4.
1, and a light guide and signal cable 43 extending from the side of the operating section 42.

A hard distal end portion 44 is provided on the distal end side of the insertion portion 41, and a bendable curved portion 46 is provided on the rear side adjacent to this distal end portion 44. Furthermore, a flexible comfort section 47 is connected to the rear of the curved section 46. The bending portion 46 can be bent vertically/horizontally by operating a bending operation knob 48 installed on the operation portion 42.

A light guide and signal connector 49 is provided at the rear end of the light guide and signal cable 43, and is connected to the connector receiver 51 of the control device 38.

The control device 38 is connected to the monitor 39 by a signal cable 52.

In FIG. 8, the tip 44 includes a rigid tip body 53. In FIG. An observation hole 54 and an illumination hole 56 are provided at the tip of the tip main body 53 in the longitudinal direction of the insertion portion 41 . An objective lens system 22 is fitted and fixed in the front part of the observation hole 54, and the image plane formed on the CCD 13 is located at the image formation position of the objective lens system 22. . A lead portion 23 is provided on the opposite image plane side of the CCD 13 so as to protrude rearward.
3. This lead portion 23 is electrically connected to the tip of a substrate 24 disposed at right angles to the CCD 13.

An electronic circuit 16 is mounted on the rear of the board 24, and a signal line 26 is electrically connected to the control device 38 via a light guide and a signal cable 43 at the rear end of the board 24. has been done.

The anti-transfer image plane of the CCD 13, the lead part 23, and the front part of the substrate 24 are filled with a first filling member 14 having low thermal conductivity, and the electronic circuit 16, the rear part of the substrate 24, and the tip of the signal line 26 are filled with the first filling member 14 having low thermal conductivity. is filled with a second filling member 17 having high thermal conductivity.

A light distribution lens 57 is fitted and fixed at the tip of the illumination through hole 56, and behind this light distribution lens 57,
A light guide 58 is provided with an end face that can transmit illumination light emitted from the control device 38 inserted through the light guide and signal cable 43.

As in this embodiment, the imaging device 1 is attached to the distal end 44 of the endoscope 137.
Even when a built-in device is installed, the same effects as in the first embodiment can be obtained.

Other functions and effects of the configuration 1 are the same as those of the first embodiment.

FIG. 9 shows a sixth embodiment of the invention.

The imaging device 1 of this embodiment is built into a camera head 2.

In this embodiment, the four end faces of the anti-transfer image plane of the CCD 13 have low thermal conductivity. Filled with tSl filling member 14, CCD
13 is designed to prevent heat from being transferred to the camera head main body 19.

The other functions and effects of the configuration 9 are similar to those of the first embodiment.

In each of the above embodiments, the substrate 24 is made of a uniform material, but the material is not limited to this.
The heat transfer rate may be changed by mixing impurities, air bubbles, etc. on the CD side.

Further, in the first to fourth and sixth embodiments, the present invention is built into the camera head, but the present invention is not limited thereto, and may be built into the distal end of an endoscope. Furthermore, in the fifth embodiment, the present invention is built into the distal end of an endoscope.
It may be provided within the camera head without being limited to this.

[Effects of the Invention] As described above, according to the present invention, since the direction of heat diffusion from the heat source can be changed depending on the direction, the total ω of heat diffusion from the heat source can be
Among these, the amount of heat dissipated to the solid-state Ia image element can be effectively reduced, and the airtight effect of sealing is also effective in protecting electrical components.

[Brief explanation of the drawing]

Figures 1 to 3 relate to the first embodiment of the present invention.
The figure is Ifll Imaging P,? 2 is an explanatory diagram of the f1@ device in the camera head, FIG. 3 is an explanatory diagram of the entire camera head device, and FIG. 4 is a second embodiment of the present invention.
An explanatory diagram of a camera head in which a laminated substrate is built in so as to face the COD. FIG. 5 is an explanatory diagram of a camera head in which a board is built in so as to face the COD, according to the third embodiment of the present invention. , FIG. 6 relates to the fourth embodiment of the present invention, and FIGS. 7 and 8 relate to the fifth embodiment of the present invention, and FIG. 7 is an explanatory diagram of the divided camera head. FIG. 8 is an explanatory diagram of the distal end of the endoscope, and FIG. 9 is an explanatory diagram of the camera head according to the sixth embodiment of the present invention. 1...Imaging device 13...Solid-state image sensor 14...First filling member 16...Electronic circuit 17...Second filling member 18...Processor section or transmission cable FIG. Figure 2 Figure 3 Figure 4 Figure 6

Claims (1)

[Scope of Claims] A solid-state image sensor as an imaging means for capturing an image of a subject, an electronic circuit connected to the solid-state image sensor, and a first device occupying a space adjacent to at least a part of the periphery of the solid-state image sensor An imaging device comprising: a component; and a second component that occupies a periphery of the electronic circuit adjacent to the first component and has higher thermal conductivity than the first component.