JPH0652933B2 - Imaging device - Google Patents

Description

The present invention relates to an image pickup apparatus having a solid-state image pickup element as an image pickup means and capable of preventing heat generated by an electronic circuit from being transferred to the solid-state image pickup element side.

[Problems to be Solved by Prior Art and Invention] In recent years, an endoscope (scope or scope) capable of diagnosing or inspecting internal organs of a body cavity by inserting an elongated insertion portion into the body cavity. Fiberscopes) have become widely used.

Further, not only for medical purposes, but also for industrial purposes, it is used for observing and inspecting objects in boilers, equipment, pipes of chemical plants and the like, or equipment.

Furthermore, various electronic scopes using a solid-state image pickup device such as a charge coupled device (CCD) as an image pickup means are also used. This electronic scope has advantages that it has a higher resolution than that of a fiberscope, that recording and reproduction of images are easy, and that image processing such as image enlargement and comparison of two screens is easy.

By the way, the electronic scope is disclosed in, for example, US Pat. No. 44.
As disclosed in Japanese Patent No. 91865, there is one in which a solid-state image pickup device is provided on a substrate, a signal line connected to the back surface side of the substrate is fixed by resin or the like, and the whole is hermetically sealed in a housing. In this case, the purpose of hermetically sealing the inside of the housing is mainly to prevent clouding due to mixing of moisture and to reinforce the strength of the housing.

In addition to the above, together with the solid-state image sensor in the housing,
In some housings, a substrate on which a drive circuit for driving the solid-state image sensor and an output buffer for outputting a video signal converted by the solid-state image sensor are mounted is provided in a housing.

In this case, the drive circuit handles a high frequency, and
When a high-capacity element such as a CCD is driven as a solid-state image sensor, the amount of heat generated is large because it needs to be driven particularly with low impedance. Further, in particular, in an image pickup apparatus in which the head unit and the process unit for processing a video signal are remotely connected by a cable or the like, the output buffer for cable transmission has low impedance conversion, that is, the amount of heat generated for current amplification. large. This generated heat amount is often larger than the generated heat amount of the solid-state image sensor. In this case, if the solid-state image sensor and the substrate are filled with resin or the like, the heat generated in the substrate stays in the housing and heats the solid-state image sensor, and as a result, the S / N ratio decreases due to the increase in dark current, and heat is generated. There is a risk of causing image quality deterioration such as noise increase.

[Object of the Invention] The present invention has been made in view of the above-mentioned points, and an imaging device capable of preventing the amount of heat generated in a housing, which electrically adversely affects the solid-state imaging device, from being transmitted to the solid-state imaging device as much as possible. The purpose is to provide.

[Means for Solving the Problems] An image pickup apparatus according to the present invention includes a solid-state image sensor as an image-capturing unit that images a subject, an electronic circuit connected to the solid-state image sensor, and at least one of the periphery of the solid-state image sensor. A first constituent member occupying a space adjacent to the portion, and a second constituent member adjacent to the first constituent member and surrounding the electronic circuit and having a lower thermal conductivity than the first constituent member. Be prepared.

[Operation] In the present invention, the filler having a lower thermal conductivity is filled in the image pickup element side than the heat source, and the filler having a higher thermal conductivity is filled in the processor or the transmission cable side than the heat source.

[Embodiment] FIGS. 1 to 3 show a first embodiment of the present invention.

The concept of the imaging device 1 will be described with reference to FIG.

A first filling member 14 as a first component is provided behind a solid-state image sensor (hereinafter abbreviated as CCD) 13 that can image a subject and on the side opposite to the image pickup 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 member 14. . A processor unit or a transmission cable 18 electrically connected to the electronic circuit 16 is further provided behind the second filling member 17.

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, α <β, and the electronic circuit 16 in the second filling member 17 is satisfied. The generated heat is less likely to be transferred to the CCD 13 and is easily transferred to the processor section or the transmission cable 18 side.

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

In FIG. 3, a camera head 2 incorporating the imaging device 1
Is detachably attached to the eyepiece 4 of the fiberscope 3. The fiberscope 3 is provided with a slender and flexible insertion portion 5 at the front portion, and a large diameter operation portion 6 is continuously provided at the rear end of the insertion portion 5. A universal cord 8 having a light source connector 7 which can transmit illumination light from a side portion of the operation portion 6 and which can be connected to a light source device (not shown) is provided at an end portion.

A signal cable 9 for transmitting a video signal is extended from the rear end of the camera head 2, and a signal connector 11 provided at the rear end of the signal cable 9 is connected to the signal processing device 12. ing. The signal processing device 12 sends a video signal to a monitor (not shown).

The camera head 2 is formed by a rigid camera head body 19, and the eyepiece 4 is detachably connectable to a front portion of the camera head body 19 with a connecting portion 21.
Is provided. An objective lens system 22 whose optical axis is aligned with the eyepiece system (not shown) of the eyepiece 4 is positioned and fixed behind the connecting portion 21. At the image forming position of the objective lens system 22, the camera head body 19
The imaging surface of the CCD 13 arranged so as not to come into direct contact with is positioned. On the side opposite to the image pickup surface of the CCD 13, a drive signal for driving the CCD 13 and CC
A lead portion 23 that can input and output the video signal photoelectrically converted by D13 projects rearward. This lead part 2
3, an electronic circuit 16 such as a drive circuit of the CCD 13 or an output circuit of the CCD 13, which is disposed so as to be at a right angle to the CCD 13, is mounted on the rear side 3 and is connected to a wiring board 24. As the material of this substrate, alumina ceramics having a thermal conductivity of 25.2 kcal / m · h · ° C or epoxy resin having a thermal conductivity of 0.14 kcal / m · h · ° C is used.

A signal line 26 inserted through the signal cable 9 is connected to a rear end portion of the substrate 24, and a video signal and a CCD are provided.
It is connected to the signal processing device 12 so as to be able to transmit the drive signal of 13 and the like.

CCD and the front of the substrate 24 in the camera head body 19
A first filling member 14 having a low thermal conductivity is filled around the side opposite to the imaging surface of 13. The material of the first filling member 14 is air having a thermal conductivity of 0.022 kcal / m · h · ° C, styrene foam having a thermal conductivity of 0.01 kcal / m · h · ° C, or the like. Further, a second filling member 17 having a higher thermal conductivity than the first filling member 14 is filled around the rear portion of the substrate 24 and around the electronic circuit 16 mounted on the substrate 24. The material of the second filling member 14 has a thermal conductivity of 0.9 kcal / m.
・ H ・ ℃ heat dissipation silicon, 0.7 kcal / m ・ h ・ ℃ cement and low-melting glass, 25.2 kcal / m ・ h ・ ℃ ceramics, etc.

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

The operation of the image pickup apparatus 1 configured as described above will be described.

The camera head 2 connected to the eyepiece 4 of the fiberscope 3 receives the subject image on the image pickup surface of the 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 CCD 1
3 is applied. The CCD 13 reads out the video signal photoelectrically converted by this drive signal, and the electronic circuit 16
Is amplified by the output circuit of the above and is sent to the signal processing device 12. The signal processing device 12 converts a video signal into a video signal and outputs the video signal to a monitor (not shown) to display an image on the screen of this monitor.

In the electronic circuit 16, the amount of heat generated is large because current amplification is performed, and this amount of heat generated diffuses in 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 which are adjacent to the second filling member 17, but the first filling member 14 is particularly different from the second filling member 17 in comparison with the second filling member 17. Since the heat conductivity is low, it takes time to transfer the generated heat amount, and most of the generated heat amount is transferred to the camera head main body 19 and the signal cable 9 and 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 transferred only from the lead portion 23.

Since the generated heat is diffused in a directional manner as in this embodiment, the amount of heat generated by the electronic circuit 16 is C
It is possible to prevent transmission to CD13 as much as possible, and
It is possible to prevent an increase in dark current caused by heating the CD 13 and increase the S / N ratio.

Furthermore, as another effect, the electronic circuit 16 and each electric 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 present invention.

In this embodiment, the substrate 24 is provided so as to face the anti-imaging surface of the CCD 13. The configuration and operation different from those of the first embodiment will be described.

A rigid camera head main body 19 constituting the camera head 2 incorporating the image pickup apparatus 1 is provided with a connecting portion 21 which is detachably connectable to the eyepiece 4 at the front portion. An objective lens system 22 whose optical axis is aligned with the eyepiece system (not shown) of the eyepiece 4 is positioned and fixed behind the connecting portion 21. At the image forming position of the objective lens system 22, the image pickup surface of the CCD 13 arranged so as not to come into direct contact with the camera head body 19 is located. On the side opposite to the image pickup surface of the CCD 13, the CCD 13
The lead portion 23 capable of transmitting the video signal photoelectrically converted by is projected rearward. The lead portion 23 is electrically connected to an upper portion of a substrate 24 which is arranged further rearward so as to face the anti-imaging surface of the CCD 13. Substrates 28, 28 ... Are laminated below the substrate 24, and a driving circuit for the CCD 13 or C is provided on the laminated substrate 28.
An electronic circuit 16 such as an output circuit of the CD 13 is mounted. A signal line 26 inserted through the signal cable 9 is connected to the substrate 28.

The upper part of the substrate 24 in the camera head body 19 and the CCD 13
Around the anti-imaging surface of the first filling member 14 having a low thermal conductivity.
The second filling member 1 having a high thermal conductivity around the substrate 28 and the electronic circuit 16 below the substrate 24.
Filled with 7.

Generally, the material used for the substrate is ceramics,
Ceramics has a high thermal conductivity and easily transfers the amount of heat generated. In this case, the heat transfer can be delayed by stacking the substrates 28 as in this embodiment. Further, the material of the substrate 28 may be partially changed.

Other configurations, operations and effects are similar to those of the first embodiment.

FIG. 5 shows a third embodiment of the present invention.

In this embodiment, the substrate 24 faces the anti-imaging surface of the CCD 13.

An imaging surface formed on the CCD 13 is located at the image forming position of the objective lens system 22 built in the front part of the camera head body 19. The lead portion 23 is provided on the anti-imaging surface of the CCD 13.
Is protruding backwards. This lead portion 23 is the CCD 13
The upper portion of the substrate 24, which is disposed so as to face the anti-imaging surface of, is electrically connected. An electronic circuit 16 is mounted on a lower portion of the board 24, and a signal line 26 inserted through the signal cable 9 is electrically connected to a lower end portion of the board 24.

The anti-imaging surface of the CCD 13 and the periphery of the substrate 24 in the Kamenra head body 19 are filled with the first filling member 14 having a low thermal conductivity. The periphery of the electronic circuit 16 below the substrate 24 is filled with a second filling member 17 having high thermal conductivity.

Other configurations, operations and effects are similar to those of the first embodiment.

FIG. 6 shows a fourth embodiment of the present 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 tip of the camera head tip member 31, an eyepiece 4 of the fiberscope 3 and a detachable connecting portion 21 are provided. An objective lens system 22 having an optical axis aligned with an eyepiece lens system (not shown) provided in the eyepiece portion 4 is provided behind the connecting portion 21. An image pickup surface formed on the CCD 13 is located at the image forming position of the objective lens system 22. The lead portion 2 is provided on the anti-imaging surface of the CCD 13.
3 is provided so as to project rearward. The lead portion 23 is electrically connected to the front portion of the substrate 24 arranged at a right angle to the CCD 13. The anti-imaging surface 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 a low thermal conductivity. The rear portion of the substrate 24 projects rearward of the camera head tip member 31. The electronic circuit 1 is provided at the rear of the protruding substrate 24.
6 is mounted, and a signal line 26 inserted through the signal cable 9 is electrically connected to the rear end portion of the board 24. The rear portion of the substrate 24, the electronic circuit 16, and the tip portion of the signal line 26 are surrounded by the camera head base member 29, and the periphery of the second filling member 1 having high thermal conductivity.
It is filled with 7. First filling member 14 and second
Of the third filling member 3 having a higher thermal conductivity than the first filling member 17 and a lower thermal conductivity than the second filling member 17
2 is filled so as to keep the distance between the camera head base member 29 and the camera head tip member 31 constant.

The thermal conductivity of the third filling member 32 may be lower than that of the first filling member 14 and may be lower than that of the second filling member 17.

With the configuration according to the present embodiment, even when the camera head is made of a material having high thermal conductivity, it is possible to prevent heat from being transferred to the tip side of the camera head having the CCD 13 built therein, and the CCD 13 is used as the camera head. It can prevent being indirectly heated by.

Other configurations, operations and effects are similar to those of the first embodiment.

7 and 8 show a fifth embodiment of the present invention.

In the present embodiment, the image pickup apparatus 1 is built in the distal end portion of the endoscope.

In FIG. 7, the endoscope device 36 includes an endoscope 37, a light source unit that supplies illumination light to the endoscope 37, and a signal processing unit that performs signal processing of an image signal output from the endoscope 37. The control device 38 has a control device 38 and a monitor 39 for displaying a video signal output from the control device 38 on a screen.

The endoscope 37 includes an elongated insertion portion 41 and the insertion portion 41.
A large-diameter operation portion 42 is continuously provided on the rear end side, and a light guide and signal cable 43 extending from the side portion of the operation portion 42.

A hard tip portion 44 is provided on the tip side of the insertion portion 41, and a bending portion 46 adjacent to the tip portion 44 and capable of bending is provided on the rear side. Further, a flexible flexible portion 47 is continuously provided behind the curved portion 46. The bending portion 46 is a bending operation knob 4 provided on the operation portion 42.
By operating 8, it is possible to bend in the vertical / horizontal directions.

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 portion 44 includes a hard tip portion main body 53. An observation through hole 54 and an illumination through hole 56 are provided in the distal end surface of the distal end portion main body 53 in the longitudinal direction of the insertion portion 41. The objective lens system 22 is fitted and fixed in the front portion of the observation through hole 54.
The image pickup surface formed on the CCD 13 is located at the image forming position 2. A lead portion 23 is provided on the side opposite to the image pickup surface of the CCD 13 so as to project rearward, and the lead portion 23 is electrically connected to a tip portion of a substrate 24 arranged at a right angle to the CCD 13. ing. The electronic circuit 16 is mounted on the rear portion of the substrate 24,
Further, at the rear end portion of the substrate 24, the signal line 2 connected to the control device 38 via the light guide and signal cable 43.
6 is electrically connected.

The anti-imaging surface of the CCD 13, the lead portion 23, and the front portion of the substrate 24 are filled with the first filling member 14 having a low thermal conductivity, and the electronic circuit 16, the rear portion of the substrate 24, and the tip portion of the signal line 26 are separated from each other. It is filled with the second filling member 17 having a high thermal conductivity.

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

The image pickup device 1 is attached to the tip portion 44 of the endoscope 37 as in the present embodiment.
The same effect as that of the first embodiment can be obtained even when the device is built in.

Other configurations, operations and effects are similar to those of the first embodiment.

FIG. 9 shows a sixth embodiment of the present invention.

The image pickup apparatus 1 of this embodiment is built in the camera head 2.

In this embodiment, the anti-imaging surface and the four end surfaces of the CCD 13 are filled with a first filling member 14 having a low thermal conductivity to prevent the CCD 13 from transmitting heat from the camera head body 19. .

Other configurations, operations and effects are similar to those of the first embodiment.

Although the substrate 24 is formed of a uniform material in each of the above-described embodiments, the present invention is not limited to this, and the C
The thermal conductivity may be changed by mixing impurities, bubbles or the like on the CD side.

Furthermore, although the first to fourth and sixth embodiments incorporate the present invention into the camera head, the present invention is not limited to this, and may be incorporated into the distal end portion of the endoscope. In addition, the fifth embodiment is one in which the present invention is built in the distal end portion of the endoscope,
The present invention is not limited to this, and may be provided inside the camera head.

[Effects of the Invention] As described above, according to the present invention, the amount of heat diffusion from the heat source can be changed depending on the direction. Therefore, of the total amount of heat diffusion from the heat source, the amount of heat radiation to the solid-state image sensor is effectively reduced. It is also possible to protect the electric parts due to the airtight effect of the sealing.

[Brief description of drawings]

1 to 3 relate to a first embodiment of the present invention.
FIG. 1 is a conceptual diagram of the image pickup device, FIG. 2 is an explanatory diagram of the image pickup device in the camera head, FIG. 3 is an explanatory diagram of the entire camera head device, and FIG. 4 is a CCD according to the second embodiment of the present invention. FIG. 5 is an explanatory view of a camera head in which substrates laminated so as to face each other are incorporated, and FIG. 5 relates to a third embodiment of the present invention, and an explanatory view of a camera head in which substrates are incorporated so as to face a CCD; FIG. 6 relates to a fourth embodiment of the present invention, and is an explanatory view of a divided camera head, FIGS. 7 and 8 relate to a fifth embodiment of the present invention, and FIG. 7 is a whole endoscope apparatus. FIG. 8 is an explanatory view of the distal end portion of the endoscope, and FIG. 9 is an explanatory view of the camera head according to the sixth embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Imaging device 13 ... Solid-state image sensor 14 ... 1st filling member 16 ... Electronic circuit 17 ... 2nd filling member 18 ... Processor part or transmission cable

Claims (1)

[Claims] 1. 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 first structure occupying a space adjacent to at least a part of the periphery of the solid-state imaging device. An image pickup apparatus comprising: a member; and a second constituent member that is adjacent to the first constituent member, occupies the periphery of the electronic circuit, and has a higher thermal conductivity than the first constituent member.