WO2011092903A1

WO2011092903A1 - Image pickup unit for endoscope

Info

Publication number: WO2011092903A1
Application number: PCT/JP2010/068197
Authority: WO
Inventors: 裕之永水; 浩一塩谷
Original assignee: オリンパスメディカルシステムズ株式会社
Priority date: 2010-02-01
Filing date: 2010-10-15
Publication date: 2011-08-04

Abstract

An image pickup unit (40) for an endoscope is provided with: an objective optical system (43) which collects the incident light flux of an optical image of a subject; an image sensor (46) in which a photoelectric conversion part (46a) and an electronic circuit part (46b) are packaged; a dioptric system (44) which is disposed on one surface of the image sensor (46) and provided with a reflective film (44a) for refracting the light flux of the optical image and focusing the optical image on the photoelectric conversion part (46a); and a protective member (45) which is joined to the dioptric system (44) so as to protect the reflective film (44a) and has higher heat conductivity than the dioptric system (44). Consequently, increase in size is prevented, and the temperature of the image sensor becomes easier to diffuse to increase heat release performance, thereby suppressing increase in temperature.

Description

Endoscope imaging unit

The present invention relates to an imaging unit for an endoscope, which is provided in an endoscope apparatus, and particularly has a refractive optical system prism.

In recent years, endoscopes are widely used in the medical field and the industrial field. In conventional endoscopes, an image guide is used, and what can observe the inside of a patient's body cavity, the inside of a jet engine, or the like at an eyepiece portion where a user looks into has been the mainstream.

In recent endoscopes, an imaging unit is incorporated at the distal end of the insertion section, and images the inside of a patient's body cavity, the inside of a jet engine, etc., and displays an endoscopic image on a display device such as an external monitor. Electronic endoscope devices have appeared.

Such an imaging unit is provided with an image sensor that photoelectrically converts detected light into an electrical signal. This image sensor is mainly used in which a solid-state imaging device, an electronic circuit, and the like are packaged as one electronic component.

In addition, an imaging unit used for an electronic endoscope is required to have a size that can be accommodated in a distal end portion that has been reduced in size as the insertion portion is reduced in diameter. Therefore, the imaging unit disposed at the distal end portion of the endoscope apparatus having a small accommodation space has a structure in which refracted light is incident on the image sensor in order to prevent the distal end portion from increasing in size in the outer diameter direction. Some use a prism.

Note that when an image sensor equipped with an electronic circuit generates heat and increases in temperature due to power consumption, problems such as deterioration of the function of the solid-state imaging device that cause image degradation occur. Therefore, in the conventional imaging unit, various devices for suppressing the temperature increase of the image sensor have been proposed.

First, for example, JP JP-A-2009-49549 discloses an imaging device technology that suppresses the temperature rise of a solid-state imaging device by covering the surface of a three-color separation prism with a heat dissipation layer formed of copper or a graphite sheet. Is disclosed.

Also, for example, in JP-A-2003-284686, a cover glass and an air gap are provided between a prism and a solid-state image sensor to conduct heat generated from a peripheral circuit arranged in the vicinity of the solid-state image sensor. A technique of an imaging apparatus for an endoscope that prevents fogging of a cover glass is disclosed.

Further, for example, in JP-A-7-255004, an elastic member formed of silicon rubber having high thermal conductivity is coated along the shape of a prism on which a heating element such as a solid-state imaging device or a substrate is mounted. Furthermore, a technology of a three-plate TV camera device having a heat dissipation structure in which a heat dissipation plate is provided on an elastic member is disclosed.

In JP 2008-278382 A, a thermally conductive silicon rubber sheet containing a temperature sensor is tightly sandwiched between the ground pattern portion of the substrate and the outer surface of the shield plate of the liquid crystal monitor by thermal bonding. An image sensor module technique for detecting an abnormal temperature rise is disclosed.
However, the imaging unit having a structure that suppresses the temperature rise as in the prior art cannot be accommodated in the small distal end portion, or it becomes a cause of inhibiting the miniaturization of the distal end portion because it is accommodated in the distal end portion. It was. For this reason, in particular, an imaging unit used in an endoscope apparatus has been desired to prevent an increase in size and to sufficiently dissipate heat from the image sensor to suppress an increase in temperature.

Therefore, the present invention has been made in view of the above circumstances, and provides an imaging unit for an endoscope that prevents an increase in size and that easily diffuses the temperature of an image sensor to improve heat dissipation and suppresses a high temperature. The purpose is to do.

The first endoscope imaging unit of the present invention includes an objective optical system that collects a light beam of an optical image of an incident subject, an image sensor in which a photoelectric conversion unit and an electronic circuit unit are packaged, A refractive optical system provided on one surface of the image sensor and provided with a reflective film that refracts a light beam of the optical image and forms an image on the photoelectric conversion unit; and the refractive optical system to protect the reflective film. And a protective member having a thermal conductivity higher than that of the refractive optical system.

The second endoscope imaging unit includes: an objective optical system that collects a light beam of an optical image of an incident subject; an image sensor in which a photoelectric conversion unit and an electronic circuit unit are packaged; A substrate electrically connected to the image sensor and having a ground layer formed on the entire surface, and the substrate is disposed so as to overlap the image sensor up to a portion where the electronic circuit unit is provided. It is characterized by.

The figure which shows the electronic endoscope system which concerns on the 1st Embodiment of this invention and contains an electronic endoscope apparatus. The perspective view which shows the inside of the front-end | tip part of an insertion part similarly The perspective view which shows the inside of the front-end | tip part by which the imaging unit was arrange | positioned similarly Same as above, a cross-sectional view of the tip where the imaging unit is disposed The perspective view showing the configuration of the imaging unit Sectional view showing the configuration of the imaging unit The top view showing the configuration of the imaging unit The bottom view showing the configuration of the imaging unit Sectional drawing which shows the structure of the imaging unit which concerns on the 2nd Embodiment of this invention. Sectional drawing which shows the structure of the imaging unit which showed the 1st modification and provided the cooling means similarly Sectional drawing which shows a 2nd modification and shows the connection state of a cooling means and a protection member FIG. 11 is a rear perspective view showing the connection state between the cooling means and the protection member of the second modification of FIG. 11. Sectional drawing which shows the structure of the imaging unit concerning the 3rd Embodiment of this invention. Same as above, enlarged view of the part circled in FIG. 13A Sectional drawing which shows the structure of the imaging unit of a 1st modification similarly Same as above, enlarged view of the circled part in FIG. 14A Sectional drawing which shows the structure of the imaging unit of a 2nd modification similarly Sectional drawing which shows the structure of the imaging unit of a 3rd modification same as the above Sectional drawing which shows the structure of the imaging unit of a 4th modification same as the above Sectional drawing which shows the structure of the front-end | tip part in which the imaging unit was provided based on the 4th Embodiment of this invention. FIG. 18 is a cross-sectional view showing a configuration of a tip portion provided with an imaging unit along the line XIX-XIX in FIG. Sectional drawing which shows the structure of the front-end | tip part which showed the modification and provided the imaging unit and arrange | positioned the cooling means similarly

Hereinafter, the imaging unit according to the present invention will be described. In the following description, the drawings based on each embodiment are schematic, and the relationship between the thickness and width of each part, the thickness ratio of each part, and the like are different from the actual ones. It should be noted that the drawings may include portions having different dimensional relationships and ratios between the drawings.

(First embodiment)
First, a first embodiment of the present invention will be described below with reference to FIGS. 1 to 8 relate to a first embodiment of the present invention, FIG. 1 is a view showing an electronic endoscope system including an electronic endoscope apparatus, and FIG. 2 is an inside of a distal end portion of an insertion portion. FIG. 3 is a perspective view showing the inside of the distal end portion where the imaging unit is disposed, FIG. 4 is a sectional view of the distal end portion where the imaging unit is disposed, and FIG. 5 is a perspective view showing the configuration of the imaging unit. 6 is a cross-sectional view showing the configuration of the imaging unit, FIG. 7 is a top view showing the configuration of the imaging unit, and FIG. 8 is a bottom view showing the configuration of the imaging unit.

As shown in FIG. 1, the electronic endoscope system 1 according to the present embodiment mainly includes an electronic endoscope device 2, a light source device 3, a video processor 4, and a monitor 5.
The electronic endoscope apparatus 2 includes a long and narrow insertion section 9, an operation section 10, an electric cable, and a universal cable 17 that is a composite cable through which a light guide bundle for transmitting illumination light is inserted, It is comprised. The insertion portion 9 of the electronic endoscope apparatus 2 includes a distal end portion 6, a bending portion 7, and a flexible tube portion 8 in order from the distal end.

In addition, the operation unit 10 is connected to one end of the flexible tube unit 8 of the insertion unit 9, and a treatment instrument channel through which various treatment instruments disposed in the insertion unit 9 and the rear mouth unit 11 that is a folding prevention unit are inserted. The treatment instrument channel insertion portion 12 that is an opening of the operation portion and the operation portion main body 13 are configured.

The operation section main body 13 is provided with a bending operation knob 16 for bending the bending section 7 of the insertion section 9, and is provided with switches for various endoscope functions. In the bending operation knob 16, a UD bending operation knob 14 for bending the bending portion 7 in the vertical direction and an RL bending operation knob 15 for bending the bending portion 7 in the left-right direction are superimposed. It is arranged.

The universal cable 17 extended from the operation unit 10 has an endoscope connector 18 that is detachable from the light source device 3 at the extended end. In addition, the electronic endoscope apparatus 2 of this Embodiment transmits illumination light from the light source device 3 to the front-end | tip part 6 with the light guide bundle which is not illustrated here. The endoscope connector 18 is provided with a coiled coil cable 19, and an electric connector 19 a detachably attached to the video processor 4 is provided at the extended end of the coil cable 19.

The video processor 4 is electrically connected to a monitor 5 that displays an endoscopic image, and is photoelectrically converted by an endoscope imaging unit (hereinafter simply referred to as an imaging unit) 20 of the electronic endoscope device 2 described later. The electrical signal is processed and output to the monitor 5 as an image signal.

As shown in FIG. 2, inside the bending portion 7 of the insertion portion 9 of the electronic endoscope apparatus 2, a plurality of substantially circular metal bending pieces 20a, which are adjacent to each other, are rotatably connected. 20b and 20c are provided. Further, the leading edge bending piece 20a is fixed to the distal end portion 6, and here, a distal end rigid portion (also referred to as a distal end constituting portion) 30 which is a distal end frame having a substantially metal outer shape is disposed. . In addition, the curved rubber | gum which is not shown here is coat | covered by the outer peripheral part of the some

bending piece

20a, 20b, 20c and the front-end | tip hard part 30 here.

The distal end hard portion 30 and the

bending pieces

20a, 20b, and 20c are provided with a treatment instrument channel 21, a light guide bundle 22, and various electric cables 23 that are inserted into the insertion portion 9.

As shown in FIG. 3, the distal end hard portion 30 has

holes

31 and 32 into which the treatment instrument channel 21 and the light guide bundle 22 are individually inserted and fixed via a metal holding tube (not shown), and the imaging unit 40. And a space portion 33 in which is disposed. The

hole portions

31 and 32 and the space portion 33 are formed from the distal end to the proximal end of the distal end hard portion 30, and an opening is formed at the distal end surface and the proximal end surface of the distal end rigid portion 30.

Next, a specific configuration of the imaging unit 40 of the present embodiment will be described below based on FIGS.

As shown in FIGS. 4 to 7, the imaging unit 40 is a substantially cylindrical lens frame 41 formed of metal or the like, a substantially cylindrical holding tube 42 formed of metal or the like, and an objective optical system. A lens group 43, a prism 44 that is a refractive optical system, a protective member 45 that is a high heat conduction member and a heat dissipation member, an image sensor 46 that is an imaging means, an FPC (flexible printed circuit board), or a TAB ( (Tape Automated Bonding) 47 and an electronic component 48.

The lens frame 41 is disposed at the forefront of the imaging unit 40, and internally holds a lens group 43 that collects a light beam of an optical image of an incident subject. At the base end portion of the lens frame 41, the tip portion of the holding tube 42 is fitted, and the lens frame 41 and the holding tube 42 are fixed by an adhesive 41a. Further, a cover glass 42 a adhered to the distal end surface of the prism 44 and an optical adhesive is inserted and fixed to the proximal end portion of the holding tube 42.

In the prism 44, the light beam of the optical image indicated by the optical axis O in the drawing, which is incident from the tip surface side through the lens group 43, is refracted by about 90 ° and reflected toward the lower surface. On the surface side of the reflecting surface 44a of the prism 44, a protection member 45, which is a block body attached with an adhesive, is fixed to protect the reflecting film on the reflecting surface 44a. The configuration of the protection member 45 will be described in detail later.

The image sensor 46 is joined to the lower surface of the prism 44 by an optical adhesive, and a photoelectric conversion unit 46a such as a CCD or CMOS is disposed on the surface of the upper surface of the image sensor 46 facing the lower surface of the prism 44. In addition, the image sensor 46 is provided with an electronic circuit unit 46b including an amplifier such as a transistor in the middle of the base end side, and the electronic circuit unit 46b is packaged together with the photoelectric conversion unit 46a. It is. A front end portion of the FPC 47 is electrically connected to the upper surface portion on the base end side of the image sensor 46.

The FPC 47 extends rearward from the image sensor 46, and has a plurality of connection lands 47a (see FIG. 7) on the upper surface of the base end portion. Further, the FPC 47 is provided with an electronic component 48 on the lower surface portion of the base end portion. The core 25a of the cable 25 is electrically connected to each connection land 47a and the electronic component 48 by soldering or the like. The electric cable 23 described above is a cable in which a plurality of cables 25 are bundled and covered with an outer sheath.

In the imaging unit 40 according to the present embodiment configured as described above, the prism 44 and the cover body 50 that is a light shielding member formed of metal or the like around the upper portion and the side portion of the protective member 45 have a predetermined distance. So as to be separated from each other. The imaging unit 40 is modularized with the adhesive layer 49 (see FIG. 4) formed by applying a reinforcing adhesive around the components after the components are assembled. Thereafter, the imaging unit 40 is arranged in the space 33 of the distal end hard portion 30 with the lens frame 41 fitted and fixed to the distal end hard portion 30. Further, the imaging unit 40 is fixed in the distal end hard portion 30 by filling the gap between the imaging unit 40 and the distal end hard portion 30 forming the space portion 33 with an adhesive 51 (see FIG. 4). Note that the adhesive layer 49 and the adhesive 51 may not be illustrated.

Further, the space portion 33 of the distal end portion 6 where the imaging unit 40 is disposed is formed with a recess 33 a in the outer diameter direction so as not to contact the electronic component 48 disposed on the lower surface of the proximal end side of the FPC 47. (See FIGS. 3 and 4).

Incidentally, photographing light indicated by the optical axis O refracted by the reflecting surface 44a of the prism 44 is incident on the photoelectric conversion unit 46a of the image sensor 46 to form an image. The photoelectric conversion unit 46a performs photoelectric conversion by generating electric charges according to the brightness of light incident on the light receiving element.

In particular, when the CCD photoelectric conversion unit 46a is used for the image sensor 46, a high-voltage analog circuit constituted by the electronic circuit unit 46b is required, and a large amount of power is required. On the other hand, when the CMOS photoelectric conversion unit 46a is used, the image sensor 46 can be driven with lower power consumption than the CCD photoelectric conversion unit 46a, but noise is generated in the captured image at low illuminance. Therefore, it is necessary to further provide a circuit for correcting noise in the electronic circuit unit 46b including the amplifier. In recent years, the photoelectric conversion unit 46a is required to have a higher pixel, and the driving frequency becomes higher and the frequency becomes higher.

As described above, the electronic circuit unit 46b of the image sensor 46 is driven by the photoelectric conversion unit 46a at a high frequency, and a circuit that requires large power consumption or a circuit that corrects noise is provided. There is a case. Therefore, in addition to causing the function of the image sensor 46 to deteriorate, in particular, in the electronic endoscope device 2, the heat of the electronic circuit portion 46 b of the image sensor 46 causes the prism 44, the cover glass 42 a, the holding tube 42, and the lens frame 41 to be heated. Therefore, heat is transferred to the distal end hard portion 30, and the distal end portion 6 of the insertion portion 9 may be heated. In addition, since the insertion portion 9 is inserted into the living body at approximately 40 °, the distal end portion 6 may be warmed by the ambient temperature in the living body. In particular, as in the electronic endoscope apparatus 2 of the present embodiment, when the light guide bundle 22 is configured to transmit illumination light, the light guide bundle 22 is heated by the transmission of illumination light. The tip 6 is also warmed by heat transfer.

As these countermeasures, in the imaging unit 40 of the present embodiment, instead of a conventional protective member formed of the same material as the prism 44 formed of glass or the like that protects the reflecting surface 44a of the prism 44, glass or the like is used. The thermal conductivity of the formed prism 44 is higher than that of, for example, a sintered body such as ceramics, a synthetic resin such as silicon, a metal such as pure copper, brass, or aluminum, or ore such as sapphire or diamond. The protection member 45 is formed of a high (large) material, and the heat absorption and heat dissipation from the image sensor 46 that generates heat is enhanced.

That is, the imaging unit 40 has a configuration in which heat generated in the electronic circuit portion 46 b of the image sensor 46 that is a heat generating portion is easily transferred to the protective member 45 formed of a material having a higher thermal conductivity than the prism 44. As a result, the protection member 45 of the present embodiment can be configured to absorb heat generated by the electronic circuit unit 46b of the image sensor 46 from the prism 44 and diffuse and dissipate the heat absorbed around the prism 44.

Moreover, since the imaging unit 40 can form the protective member 45 with substantially the same size as the conventional one, an increase in size in the outer diameter direction is prevented. As a result, the enlargement of the outer shape of the distal end portion 6 in which the imaging unit 40 is incorporated is also prevented.

From the above description, the imaging unit 40 of the present embodiment can be configured to prevent an increase in size, to easily diffuse the temperature of the image sensor 46, to improve heat dissipation, and to suppress a high temperature.

(Second Embodiment)
Next, an imaging unit according to the second embodiment will be described below based on FIGS. 9 to 12.
9 and 10 relate to the second embodiment of the present invention, FIG. 9 is a cross-sectional view showing the configuration of the imaging unit, FIG. 10 shows a first modification, and cooling means is provided. FIG. 11 is a sectional view showing the configuration of the imaging unit, FIG. 11 is a sectional view showing a connection state between the cooling means and the protection member, and FIG. 12 is a cooling means and protection member according to the second modification of FIG. It is a back perspective view which shows the connection state of. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals for the convenience of description, and detailed description and operational effects of those components are omitted.

As shown in FIG. 9, the imaging unit 40 of the present embodiment is provided with a protective member 45 having a length that overlaps the upper surface of the image sensor 46 in the portion where the electronic circuit portion 46 b is provided. .

That is, as in the first embodiment, the protective member 45 of the present embodiment has a higher thermal conductivity than the prism 44 made of a transparent member such as glass, for example, sintered ceramics or the like. Body, a synthetic resin such as silicon, a metal such as pure copper or aluminum, or an ore such as sapphire, and has a length up to a position covering the electronic circuit portion 46b, and is provided on the upper surface of the image sensor 46. .

Note that the protective member 45 has a configuration in which only the length in the longitudinal axis direction parallel to the longitudinal direction of the imaging unit 40 is extended with respect to the configuration of the first embodiment, and the size around the longitudinal axis. (Outer shape of the distal end portion 6 in the outer diameter direction) has the same dimensions as in the first embodiment.

In the imaging unit 40 of the present embodiment configured as described above, the protective member 45 made of a material having a higher thermal conductivity than the material of the prism 44 is placed on the upper surface of the image sensor 46 to a position where it covers the electronic circuit portion 46b. Since the heat of the electronic circuit unit 46b is directly transferred to the protection member 45 by providing the heat absorption and heat dissipation of the heat from the electronic circuit unit 46b of the image sensor 46 as compared with the first embodiment. The configuration can be improved.

In other words, the imaging unit 40 is formed of a material having a higher thermal conductivity than the prism 44, which is disposed in the vicinity so as to cover the electronic circuit unit 46 b so that the heat of the electronic circuit unit 46 b serving as the heat generating unit in the image sensor 46. The protection member 45 is configured to easily transfer heat directly. As a result, the protection member 45 of the present embodiment further directly absorbs the heat generated by the electronic circuit unit 46b of the image sensor 46 and absorbs it in the surroundings as compared to the configuration of the first embodiment. It is possible to dissipate the generated heat and dissipate it.

Further, since the imaging unit 40 does not change the size of the protective member 45 around the longitudinal axis, the enlargement in the outer diameter direction is prevented as in the first embodiment. Therefore, similarly to the effect of the first embodiment, the enlargement of the outer shape of the distal end portion 6 in which the imaging unit 40 is built is prevented.

In addition, as shown in FIG. 10, as for the protection member 45, the cooling member 55 which is cooling means, such as a heat pipe and a heat radiating wire, may be connected to the base end surface. The cooling member 55 is extended rearward by a predetermined length, and the whole excluding the tip end portion is covered with an outer sheath 56. Moreover, the front-end | tip part of the cooling member 55 is connected with the base end surface of the protection member 45 by the adhesive part 57 with high heat conductivity which is solder or brazing, for example.

As shown in FIGS. 11 and 12, a hole 45 a is formed in the base end surface of the protection member 45, and the distal end portion of the cooling member 55 is press-fitted into the hole 45 a, or the distal end portion of the cooling member 55. May be connected by soldering or brazing with high thermal conductivity, for example.

As described above, the imaging unit 40 according to the present modification includes the cooling member 55 that moves the heat of the protection member 45 that absorbs heat generated by the electronic circuit unit 46b of the image sensor 46 to the rear, in addition to the above-described effects. Furthermore, heat can be moved to the cooling member 55 to enhance the heat diffusibility, and the heat from the image sensor 46 can be prevented from moving to the tip side. Needless to say, the cooling member 55 has a sufficient heat diffusing effect even if it is provided in the configuration of the imaging unit 40 of the first embodiment.

(Third embodiment)
Next, an imaging unit according to the third embodiment will be described below based on FIGS.
13 to 17 relate to the third embodiment of the present invention, FIG. 13A is a cross-sectional view showing the configuration of the imaging unit, FIG. 13B is an enlarged view of a portion surrounded by a circle in FIG. 13A, and FIG. FIG. 14B is an enlarged view of a portion surrounded by a circle in FIG. 14A, FIG. 15 is a cross-sectional view showing the configuration of the imaging unit showing the second modification, FIG. 16 is a cross-sectional view showing a configuration of an imaging unit showing a third modification, and FIG. 17 is a cross-sectional view showing a configuration of an imaging unit showing a fourth modification. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals for the sake of convenience of description, and detailed descriptions and operational effects of those components are omitted.

In the imaging unit 40 of the present embodiment, as shown in FIG. 13, the FPC 47 is disposed up to a position where it overlaps the upper surface of the image sensor 46 in the portion where the electronic circuit portion 46 b is provided. The FPC 47 is provided with a ground layer 62a and a signal line 62b which are covered with an insulating film on a cover lay 61 such as a polyimide film.

The ground layer 62a is patterned on substantially the entire surface of the FPC 47. That is, the FPC 47 is disposed so as to overlap the upper surface of the image sensor 46 so as to cover the electronic circuit portion 46b of the image sensor 46 including the ground layer 62a.

As described above, in the imaging unit 40 according to the present embodiment, the ground layer 62a is provided on the upper surface of the image sensor 46 to the position where the tip portion of the FPC 47 in which the ground layer 62a is patterned on the entire surface covers the electronic circuit portion 46b. Since the heat from the electronic circuit unit 46b is directly transferred to the layer 62a, the heat absorption and heat dissipation of the heat from the electronic circuit unit 46b that generates heat in the image sensor 46 is further improved as compared with the first embodiment. It can be configured.

In other words, the imaging unit 40 directly transfers heat generated in the electronic circuit unit 46b of the image sensor 46, which is a heat generating unit, to the ground layer 62a of the FPC 47 disposed in the vicinity so as to cover the electronic circuit unit 46b. It is configured to be heated. In addition to this, similarly to the first embodiment, the protection member 45 absorbs and dissipates heat from the image sensor 46 transferred to the prism 44.

Therefore, the imaging unit 40 of the present embodiment further absorbs heat generated by the electronic circuit unit 46b of the image sensor 46 directly by the ground layer 62a of the FPC 47, as compared with the configuration of the first embodiment. The heat moves to the rear side of the FPC 47, and the heat absorbed by the ground layer 62a is diffused around the FPC 47 to dissipate it.

As described above, the imaging unit 40 of the present embodiment absorbs the heat generated by the electronic circuit unit 46b of the image sensor 46 by the ground layer 62a of the FPC 47 and transfers it to the rear of the FPC 47, and the heat is transferred to the periphery of the FPC 47. The heat of the image sensor 46 that has not been absorbed by the ground layer 62 a of the FPC 47 is absorbed and dissipated by the protective member 45 through the prism 44. Therefore, in addition to the effects of the first embodiment, the imaging unit 40 can further increase the heat diffusibility and prevent the heat of the image sensor 46 from moving to the front end side.

Further, as shown in FIG. 14, the imaging unit 40 may be provided with FPCs 47 each having a ground layer 62 a patterned on substantially the entire surface, on both upper and lower surfaces of the image sensor 46.
Specifically, the FPC 47 on which the electronic component 48 is mounted on the lower surface is disposed on the lower surface of the image sensor 46 until the tip portion covers the electronic circuit portion 46b. The newly provided FPC 63 simply has a structure in which a ground layer 65 with an insulating coating is provided on a cover lay 64 such as a polyimide film, and the image is such that the tip portion overlaps to a position covering the electronic circuit portion 46b. The sensor 46 is disposed on the upper surface.

In the new FPC 63, only the ground layer 65 is patterned on almost the entire surface, and here, no other circuit configuration is mounted, and no wiring pattern is formed therefor. The core 25a of the cable 25 is connected to the FPC 63 by soldering or the like so as to be electrically connected to the ground layer 65.

In the imaging unit 40 of this modification configured as described above, the heat generated in the electronic circuit portion 46b of the image sensor 46, which is a heat generating portion, is directly applied to the ground layers 62 and 65 of the two

FPCs

47 and 63, respectively. Heat is transferred. Then, the heat moves to the rear side of each

FPC

47, 63 by the ground layers 62, 65 of the two

FPCs

47, 63 that directly absorb the heat generated by the electronic circuit portion 46b of the image sensor 46, and the absorbed heat is absorbed. It diffuses and radiates heat around each

FPC

47, 63.

Therefore, in addition to the above-described effects, the imaging unit 40 of the present modification can further improve the heat diffusibility, and can prevent the heat of the image sensor 46 from moving to the tip side. Also in this configuration, the protection member 45 absorbs and dissipates heat from the image sensor 46 transferred to the prism 44.

Here, the configuration in which the

FPCs

47 and 63 are arranged on two different surfaces (upper and lower surfaces) of the image sensor 46 is shown, but the image sensor 46 is overlapped to a position where the tip portion covers the electronic circuit portion 46b. The FPC 63 may be provided on the other surface (side surface).

Of course, such a configuration including the FPC 47 (FPC 63) in which the ground layer 62a (65) is patterned on substantially the entire surface may be provided in the configuration of the imaging unit 40 of the second embodiment. Further, the protective member 45 is sufficiently made of the same material as that of the prism 44 as in the prior art, and even if only the configuration including the FPC 47 (FPC 63) of the present embodiment is provided, it has a sufficient heat diffusing effect as compared with the prior art. Of course.

The configuration in which the FPC 47 (FPC 63) having the ground layer 62 patterned on substantially the entire surface is provided so as to overlap the position covering the electronic circuit portion 46b of the image sensor 46 is provided in the imaging unit 40 having the prism 44 of the refractive optical system. Without being limited, the present invention can also be applied to an imaging unit including various image sensors 46. Further, the FPC 47 (FPC 63) may be a rigid substrate.

As shown in FIG. 15, in the imaging unit 40, the FPC 47 and the FPC 63, which are provided so as to overlap the top and bottom surfaces of the image sensor 46 up to a position where the tip portion covers the electronic circuit portion 46b, are shown in FIG. It may be provided upside down with respect to the configuration.

In addition, as shown in FIG. 16, the imaging unit 40 is arranged on a position where an electronic component 48 such as a capacitor constituting an electric passive element disposed in the FPC 47 covers the electronic circuit unit 46 b of the image sensor 46. It may be provided. In such a configuration, the heat of the electronic circuit unit 46, which is an electrically active element, is also transferred to the electronic component 48, so that the heat dissipation diffusivity of the imaging unit 40 can be further increased.

Further, as shown in FIG. 17, the imaging unit 40 may be provided on the base end side with respect to the image sensor 46, and a heat radiating member 58 may be provided between the FPC 47 and the FPC 63. The heat radiating member 58 absorbs the heat of the electronic component 48 of the image sensor 46 which is absorbed by the FPC 47 and the FPC 63 and is transferred to the base end side to dissipate the heat. be able to.

(Fourth embodiment)
Next, an imaging unit according to a fourth embodiment will be described below based on FIGS.
18 to 20 relate to the fourth embodiment of the present invention, FIG. 18 is a cross-sectional view showing the configuration of the tip portion provided with the imaging unit, and FIG. 19 is taken along line XIX-XIX in FIG. FIG. 20 is a cross-sectional view showing the configuration of the distal end portion provided with the imaging unit and provided with cooling means. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals for the sake of convenience of description, and detailed descriptions and operational effects of those components are omitted.

As shown in FIGS. 18 and 19, the distal end portion 6 of the electronic endoscope apparatus 2 of the present embodiment is provided with a cylindrical resin frame 70 on the outer peripheral portion of the distal end hard portion 30.
The resin frame 70 is fitted and bonded to the outer peripheral portion of the distal end hard portion 30 at the distal end portion. The base end portion of the resin frame 70 is bonded and bonded so that the inner peripheral surface thereof is in surface contact with the outer peripheral surface of the distal end hard portion 30 (not shown).

In addition, the distal end hard portion 30 is formed with a concave portion in the circumferential direction by scraping the outer peripheral portion of the portion to which the resin frame 70 is fitted out by a predetermined thickness around the longitudinal axis within a predetermined length range in the longitudinal direction. . For this reason, in the tip portion 6, an air layer 71 is formed between the tip hard portion 30 and the resin frame 70 in a state where the resin frame 70 is externally fitted to the tip hard portion 30. The resin frame 70 and the hard tip portion 30 are hermetically fitted and bonded with an adhesive or the like.

With such a configuration, the distal end portion 6 of the electronic endoscope apparatus 2 according to the present embodiment is insulated by the air layer 71 from the heat of the imaging unit 40 serving as a heating element disposed in the distal end hard portion 30. Due to the effect, it is difficult to be transmitted to the resin frame 70 which is the outer surface, and a temperature rise due to heat from the inside is suppressed. Thereby, the high temperature of the front-end | tip part 6 of the electronic endoscope apparatus 2 can be prevented.

As shown in FIG. 20, a cooling member 72 that is a cooling means such as a heat pipe or a heat radiating wire may be provided in the distal end hard portion 30. The cooling member 72 extends rearward with a predetermined length, and is entirely covered with an outer sheath 73 except for the distal end portion. Moreover, the front-end | tip part of the cooling member 72 is connected with the inner surface of the front-end | tip hard part 30 which forms the space part 33 by the adhesive part 74 with high heat conductivity which is solder or brazing, for example.

As described above, the distal end portion 6 of the electronic endoscope apparatus 2 of the present modification is provided with the cooling member 72 that moves the heat of the distal end hard portion 30 heated by the heat transfer from the imaging unit 40 to the rear. Since the heat is diffused by this, the internal temperature can be suppressed to a certain value or less, and in addition to the above-described effects, it is possible to further prevent the temperature from rising.

It should be noted that the configuration of the distal end portion 6 of the electronic endoscope of the present embodiment described above can be used together with the imaging unit 40 described in the above-described embodiments. Further, the configuration of the FPC 47 of each of the above-described embodiments is not limited to this, and a TAB tape may be used.

The invention described above is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention at the stage of implementation. Further, each embodiment includes various stages of the invention, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements.

For example, even if some constituent requirements are deleted from all the constituent requirements shown in each embodiment, this constituent requirement can be obtained when the described effect can be obtained for the problem to be solved by the invention. A configuration in which is deleted can be extracted as an invention.

This application is filed on the basis of the priority claim of Japanese Patent Application No. 2010-020495, filed in Japan on February 1, 2010, and the above-mentioned contents include the present specification, claims, and It is cited in the drawing.

Claims

An objective optical system that collects a light beam of an optical image of an incident subject;
An image sensor in which a photoelectric conversion unit and an electronic circuit unit are packaged;
A refractive optical system provided on one surface of the image sensor and provided with a reflective film that refracts a light beam of the optical image and forms an image on the photoelectric conversion unit;
A protective member bonded to the refractive optical system so as to protect the reflective film, and having a higher thermal conductivity than the refractive optical system;
An imaging unit for an endoscope, comprising:
2. The endoscope imaging unit according to claim 1, wherein the protective member is disposed so as to overlap the image sensor up to a portion where the electronic circuit unit is provided.
3. The endoscope imaging unit according to claim 1, wherein a cooling member is connected to the protective member.
4. The endoscope imaging unit according to claim 3, wherein the cooling member is connected to the protective member by an adhesive portion having high thermal conductivity.
The refractive optical system is formed of glass;
5. The inner member according to claim 1, wherein the protective member is made of a sintered body, a synthetic resin, a metal, or an ore having a higher thermal conductivity than the glass. Imaging unit for endoscope.
A substrate electrically connected to the image sensor and having a ground layer formed on the entire surface,
2. The endoscope imaging unit according to claim 1, wherein the substrate is disposed so as to overlap the image sensor up to a portion where the electronic circuit unit is provided.
A plurality of the substrates disposed on different surfaces of the image sensor;
The endoscope imaging unit according to claim 6, wherein the plurality of substrates are arranged to overlap the image sensor up to a portion where the electronic circuit unit is provided.
An objective optical system that collects a light beam of an optical image of an incident subject;
An image sensor in which a photoelectric conversion unit and an electronic circuit unit are packaged;
A substrate electrically connected to the image sensor and having a ground layer formed on the entire surface;
With
The imaging unit for an endoscope, wherein the substrate is disposed so as to overlap the image sensor up to a portion where the electronic circuit unit is provided.
A plurality of the substrates disposed on different surfaces of the image sensor;
The endoscope imaging unit according to claim 8, wherein the plurality of substrates are arranged so as to overlap the image sensor up to a portion where the electronic circuit unit is provided.