JP2019024942A - Endoscope imaging unit and endoscope - Google Patents

Abstract

To provide an endoscope imaging unit in which is suppressed the delamination of a prism and a cover glass bonded to each other via an adhesion layer, and also to provide an endoscope including such an endoscope imaging unit.SOLUTION: An endoscope imaging unit 30 comprises: objective lenses; a mirror barrel 50 retaining the objective lenses; a prism 60 having a light incidence plane directly or indirectly connected to one end of the mirror barrel 50 and a light outgoing plane square to the light incidence plane; a flat optical member 40 of which one surface is bonded, via an adhesive 70, to one of the light incidence plane and the light outgoing plane of the prism 60; and an imaging element board 80 arranged facing the light outgoing plane of the prism. The mirror barrel 50 is partially opposite the imaging element board 80 with a predetermined gap G arranged therebetween. One side of a corner formed by the light incidence plane and the light outgoing plane of the prism 60 at the interface between the prism and the flat optical member 40 faces the gap between the mirror barrel and the imaging element board. A tip portion 42 of a corner of the flat optical member is cut out, which faces a corner 60c formed by the light incidence plane and the light outgoing plane of the prism 60.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an endoscope imaging unit and an endoscope.

  An imaging unit in which an imaging element is mounted at the distal end of a flexible elongated insertion tool is built-in, and by inserting this insertion tool into a body cavity, it is possible to observe a region to be examined. An endoscope is known.

  This imaging unit incorporates a solid-state imaging device such as a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor) image sensor, and forms an optical image of the subject region in the light receiving area of the imaging device through a plurality of optical members. Then, the image data of the region to be imaged is captured by the photoelectric conversion process of the image sensor.

  The optical member provided in the imaging unit is, for example, a lens system, a prism, and a cover glass that protects the imaging surface of the imaging device. In order to accurately reproduce an observation image, the relative positional relationship between a plurality of optical members is used. Therefore, it is necessary to assemble the imaging unit in a state in which is strictly regulated. On the other hand, there are electronic components such as capacitors mounted on the substrate of the image sensor and heat sources such as light guides at the position where the imaging unit is placed in the insertion section of the endoscope, so the ambient temperature rises during use. The temperature is about 50 to 60 ° C. In addition, the insertion part is exposed to a high-temperature, high-pressure, high-humidity atmosphere for autoclave sterilization.

  Here, among the members constituting the imaging unit, the lens barrel is formed of a metal material such as brass, aluminum, and stainless steel, and the material of the prism and the cover glass is glass or resin. The linear expansion coefficient of each member varies depending on the material, and the difference in linear expansion coefficient between a lens barrel made of a metal material and a prism or cover glass made of glass or resin is extremely large. For this reason, when the lens barrel and the prism or the cover glass are connected with an adhesive, they are connected with the adhesive while being operated for a long time in a high temperature atmosphere or repeatedly operating. Due to the difference in the coefficient of linear expansion between the members, distortion may occur in the connecting portion between them, and separation may occur in the bonded portion.

  Patent Document 1 proposes a configuration in which the lens barrel and the cover glass are arranged apart from each other on the assumption that the most affected by the difference in the linear expansion coefficient is between the lens barrel and the cover glass.

  Also in Patent Documents 2 to 4, etc., a lens barrel equipped with a lens system and a prism are fixed, and further, a prism and a cover glass provided on the surface of the image sensor are fixed using an adhesive or the like. The configuration is disclosed.

No. 7-24088 JP2015-42219A JP 2012-105868 A JP 2011-224348 A

  In order to reduce the burden on the subject, the insertion portion of the endoscope is reduced in diameter. The present inventors have found the following problems in proceeding with studies for realizing this reduction in diameter. In order to reduce the diameter of the insertion portion, it is necessary to sufficiently reduce the interval between the lens barrel and the image pickup device substrate disposed to face the outer surface of the lens barrel. However, if the distance between the lens barrel and the image pickup device substrate is reduced, the adhesive leaking from the interface when bonding the interface between the cover glass and the prism is part of the outer peripheral surface of the lens barrel (hereinafter referred to simply as the outer surface). .) And the image sensor substrate. When the insertion portion is exposed to a high temperature in a state where the outer surface of the lens barrel and the image sensor substrate are buried with an adhesive, the expansion of the adhesive or the lens barrel causes the space between the lens barrel and the image sensor substrate. Stress in the direction of separating is applied. This stress affects the bonding surface between the prism and the cover glass, and a force in the direction of separating both members is also applied to the bonding surface between the prism and the cover glass. While the insertion portion is exposed to a high temperature for a long time or repeatedly exposed to a high temperature, the adhesive surface peels off due to the influence of the force applied in the direction of separating the prism and the cover glass. Peeling on the bonding surface between the prism and the cover glass significantly reduces the accuracy of the received light image.

  The present invention has been made in view of the above circumstances, and is provided with an endoscope imaging unit and an endoscope imaging unit in which peeling between the cover glass and the prism that are bonded and fixed is suppressed. An object is to provide an endoscope.

The endoscope imaging unit of the present invention is
An objective lens disposed at the distal end of the insertion portion of the endoscope;
A lens barrel for holding an objective lens;
A light incident surface connected directly or indirectly to one end of the lens barrel, and a prism having a light exit surface perpendicular to the light incident surface;
A flat optical member having one surface bonded to either one of the light incident surface and the light emitting surface of the prism via an adhesive;
An imaging unit for an endoscope comprising an imaging device substrate disposed to face the light exit surface of the prism,
The lens barrel and the image pickup device substrate have a portion arranged to face each other with a predetermined gap,
One side of the interface between the prism and the flat plate optical member at the corner formed by the light incident surface and the light exit surface of the prism faces the gap between the lens barrel and the image sensor substrate,
A notch is provided at the corner of the flat optical member facing the corner formed by the light incident surface and the light exit surface of the prism.

  In the endoscope imaging unit of the present invention, it is preferable that a notch is provided at the corner of the prism.

  In the endoscope imaging unit of the present invention, even if the notch at the corner of the flat optical member, or the notch at the corner of the flat optical member and the notch at the corner of the prism are chamfered portions. Good.

  In the endoscope imaging unit of the present invention, the flat optical member may be a cover glass bonded to the light exit surface of the prism.

  In the endoscope imaging unit of the present invention, the flat optical member may be an optical filter disposed between one end of the lens barrel and the light incident surface of the prism.

  In the endoscope imaging unit according to the present invention, it is preferable that the prism is disposed so that a corner portion of the prism protrudes outside the outer periphery of the lens barrel.

  In the endoscope of the present invention, the endoscope imaging unit of the present invention is mounted on the distal end portion of the endoscope that is inserted into the subject.

  In the endoscope imaging unit of the present invention, one side of the corner portion formed by the light incident surface and the light emitting surface of the prism at the interface between the prism bonded with the adhesive and the flat optical member faces the gap. Since the notch is provided at the corner of the flat optical member facing the corner of the prism, the adhesive leaking from the interface between the prism and the flat optical member is received by the notch when the prism is bonded to the flat optical member. Therefore, it is possible to prevent the adhesive from leaking into the gap between the lens barrel and the imaging element substrate. Therefore, when an adhesive is filled in the gap between the lens barrel and the imaging device substrate, the force applied to the adhesive surface between the prism and the cover glass can be suppressed, and peeling of the adhesive surface between the two is suppressed. An imaging unit for endoscope can be obtained.

It is a figure showing the whole endoscope apparatus composition concerning one embodiment. It is sectional drawing of the front-end | tip part of an endoscope. It is a perspective view which shows an example of a flexible substrate. It is a side view showing a schematic structure of an imaging unit concerning one embodiment. It is a figure which shows an example of the corner | angular part shape of a prism and a cover glass (the 1). It is a figure which shows an example of the corner | angular part shape of a prism and a cover glass (the 2). It is a perspective view which shows each shape before adhesion | attachment of the prism and cover glass of FIG. It is a figure which shows an example of the corner | angular part shape of a prism and a cover glass (the 3). It is a figure which shows an example of the corner | angular part shape of a prism and a cover glass (the 4). It is a figure which shows an example of the corner | angular part shape of a prism and a cover glass (the 5). It is a side view which shows schematic structure of the imaging unit of the example of a design change.

Embodiments according to the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram illustrating an overall configuration of an endoscope apparatus 11 including an endoscope according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view illustrating an enlarged distal end of an insertion portion of the endoscope. is there.

  As shown in FIG. 1, the endoscope device 11 includes an endoscope 12, a control device 13, a light source device 14, and an air / water supply device 15. The air / water supply device 15 is built in the light source device 14, and is a well-known air supply device (for example, a pump) 15 a that supplies air, and a wash water tank that is provided outside the light source device 14 and stores wash water. 15b.

  The endoscope 12 is connected to a flexible insertion portion 16 to be inserted into the body of a subject and a proximal end portion of the insertion portion 16, and is used for grasping the endoscope and operating the insertion portion 16. And a universal cord 19 that connects the operation unit 17 to the control device 13 and the light source device 14.

  The insertion portion 16 is provided at the distal end thereof, and is freely bent so as to be connected to the distal end portion 16a in which the endoscope imaging unit 30 according to the first embodiment of the present invention is built, and the proximal end of the distal end portion 16a. The curved portion 16b and a flexible tube portion 16c having flexibility and connected to the proximal end of the curved portion 16b. Here, the base end means one end on the operation unit 17 side of both ends of each member.

  The operation portion 17 is provided with operation members such as an angle knob 21 for bending the bending portion 16b up and down, left and right, and an air supply / water supply button 22 for ejecting air and water from the distal end portion 16a. Further, the operation unit 17 is provided with a forceps port 23 for inserting a treatment tool such as an electric knife into a forceps channel (see FIG. 2) 32.

  The control device 13 is electrically connected to the light source device 14 and comprehensively controls the operation of the endoscope device 11. The control device 13 supplies power to the endoscope 12 via the universal cord 19 or a transmission cable inserted into the insertion portion 16 and controls the driving of the image sensor 82. In addition, the control device 13 acquires an imaging signal output from the imaging element 82 via the transmission cable, performs various image processing, and generates image data. The image data generated by the control device 13 is displayed as an observation image on the monitor 20 connected to the control device 13 with a cable.

  As shown in FIG. 2, the distal end portion 16 a includes a distal end rigid portion 24 and a distal end protective cap 25 attached to the distal end side of the distal end rigid portion 24. The distal end hard portion 24 is made of a metal such as stainless steel, and a plurality of through holes are formed along the longitudinal direction. Various parts such as the imaging unit 30, the forceps channel 32, and a light guide (not shown) are inserted and fixed in the through holes of the distal end rigid portion 24. The rear end of the distal end rigid portion 24 is connected to the distal bending piece 33 constituting the bending portion 16b. In addition, the outer periphery of the distal end rigid portion 24 is covered with an outer tube 34.

  The imaging unit 30 holds an objective lens 38 disposed on the distal end side of the distal end portion 16a in order to capture image light in the body cavity (that is, in the subject) from the observation window of the distal protective cap 25, and the objective lens 38. A lens barrel 50, a prism 60 connected to one end 50A on the base end side of the lens barrel 50, a cover glass 40 bonded to the prism 60, and an image pickup device arranged to face the light emitting surface 60B of the prism 60 And a substrate 80. The cover glass 40 is a form of a flat optical member.

  The prism 60 includes a light incident surface 60A connected to one end 50A of the lens barrel 50, and a light emitting surface 60B perpendicular to the light incident surface 60A. One surface 40A of the cover glass 40 is bonded to the light emitting surface 60B of the prism 60 via an adhesive 70 (see FIG. 3).

  The objective lens 38 includes lens groups 38A, 38B, and 38C for capturing image light in the subject, and the lens barrel 50 holds the lens groups 38A, 38B, and 38C therein. Among the lens groups 38A, 38B, and 38C, the lens 38A that is located closest to the distal end side is disposed so as to face the outside from the distal end surface of the distal end portion 16a, that is, the through hole 25a of the distal end protection cap 25.

  The image sensor substrate 80 is provided with an image sensor 82, and the cover glass 40 is disposed on the light receiving portion 84 of the image sensor 82. The cover glass 40 is a thin plate made of a transparent material and having a thickness of about 0.2 mm to 0.5 mm. The cover glass is not limited to glass but may be made of resin. In the present embodiment, the cover glass 40 is attached in direct contact with the surface of the light receiving portion 84, but the cover glass 40 may be attached on the light receiving portion 84 via a spacer.

  The image pickup device substrate 80 includes a silicon substrate 81 provided with an image pickup device 82 and a flexible substrate 85 provided with a circuit unit. The circuit unit is electrically connected to the image sensor 82. In the circuit unit, for example, a circuit for transmitting a drive signal for driving the image sensor 82, a circuit for performing signal processing such as digitizing the image signal from the image sensor 82, and the image signal are transferred to the control device A circuit or the like for mounting is mounted.

  The light receiving surface 84 of the image pickup element 82 of the silicon substrate 81 is closely exposed to the outer surface of the one end portion 85a so that the light receiving surface 84 is exposed from the opening 85b (see FIG. 3) formed in the one end portion 85a of the flexible substrate 85. It is electrically connected to one end 85a by a bonding wire. The flexible substrate 85 has a curved portion 85c that is curved in a U-shape, and the other end portion 85e reaches the vicinity of the prism 60 through a straight portion 85d that extends substantially straight.

  The predetermined length range of the other end portion 85e is bent with respect to the linear portion 85d so as to be substantially parallel to the inclined surface of the prism 60. On the surface of the other end 85e on the prism 60 side, components such as a circuit for driving the image sensor 82 and an amplifier for amplifying a video signal output from the image sensor 82 are provided. A cover 86 is fixed to the other end 85 e, and both edges of the cover 86 are fixed to both side surfaces of the prism 60.

  As shown in FIG. 3, the flexible substrate 85 has a branch portion 85f that protrudes in a direction perpendicular to the longitudinal direction of the straight portion 85d and is bent at a right angle. 85 g is continuously provided. The surface of the sub-board 85g is perpendicular to the surface of the branch portion 85f and is substantially parallel to the surface of the straight portion 85d. A soldering portion 85h is provided on the inner surface of the sub-board 85g facing this surface, and signal lines are soldered to a large number of terminals provided on the soldering portion 85h.

  Hereinafter, the imaging unit 30 according to the first embodiment of the present invention provided in the endoscope apparatus 11 will be described in detail. FIG. 4 is an enlarged side view of the connecting portion of the lens barrel 50, the prism 60, and the cover glass 40 of the imaging unit 30 of the present embodiment. A part of the image sensor substrate is omitted.

  In the imaging unit of the present embodiment, the light incident surface 60A of the prism 60 is connected to one end 50A on the base end side of the lens barrel 50 as shown in FIG. The lens barrel 50 and the prism 60 are connected via an adhesive (not shown). The light emitting surface 60 </ b> B of the prism 60 is bonded to one surface 40 </ b> A of the cover glass 40 via an adhesive 70. Hereinafter, a layer made of the adhesive 70 at the interface between the prism 60 and the cover glass 40 is referred to as an adhesive layer 72.

  As shown in FIG. 4, the lens barrel 50 and the image pickup device substrate 80 have a portion in which they are opposed to each other with a predetermined gap G. In the present embodiment, the outer surface of the lens barrel 50 and the end portion 85i of the flexible substrate 85 disposed to face the outer surface are disposed in the gap G described above. The gap G varies depending on the configuration of the imaging unit and the arrangement of each member, but is 0.1 mm to 0.2 mm in the present embodiment, for example.

One side 75 of the interface between the prism 60 and the cover glass 40 on the corner 60C side formed by the light incident surface 60A and the light emitting surface 60B of the prism 60 is disposed at a position facing the gap G.
The cover glass 40 includes a notch 42 at a corner 40 </ b> C facing the corner 60 </ b> C of the prism 60. The notch 42 is a chamfered portion formed by chamfering the ridgeline of the cover glass 40. For example, a cover glass having a thickness of about C0.1 to C0.2 is suitable for a cover glass having a thickness of 0.2 mm to 0.5 mm. The chamfered portion is not limited to C chamfering (45 ° chamfering), and may be any angle or R chamfering. Note that the shape of the notch 42 is not limited as long as it can receive surplus adhesive, and may be a stepped portion, a recess, or the like.

  The prism 60 and the cover glass 40 are bonded by an adhesive 70 over almost the entire surface. On the other hand, the image light detected by the objective lens passes through the cover glass 40 through the prism 60 and enters the light receiving portion 84 of the image sensor 82. That is, since the adhesive layer 72 is provided in the optical path of the image light in the prism 60 and the cover glass 40, if the adhesive layer 72 is peeled off, the received light image is greatly affected. According to the imaging unit 30 of this configuration, the adhesive 70 leaking from the side 75 on the lens barrel 50 side of the interface between the prism 60 and the cover glass 40 when forming the adhesive layer 72 is notched in the cover glass 40. It is possible to suppress the adhesive 70 that is received by 42 and leaks into the gap G.

  As in the present embodiment, when the gap G between the lens barrel 50 and the imaging element substrate 80 is as narrow as 0.1 mm to 0.2 mm, if the cover glass 40 does not have the notch 42, the adhesive 70 Enters the gap G and is filled. When the adhesive is embedded in the gap G between the lens barrel 50 and the imaging element substrate 80, as described above, the prism 60 and the cover glass 40 may be peeled off due to the expansion and peeling of the adhesive. According to the configuration, leakage of the adhesive 70 into the gap G is suppressed, and as a result, peeling between the prism and the cover glass is suppressed. Since the imaging unit 30 of the present embodiment has a configuration in which peeling between the prism 60 and the cover glass 40 is suppressed, it is possible to obtain high durability when repeatedly receiving a high-temperature and high-humidity environment.

  5-9 is a figure for demonstrating the corner | angular part shape of the prism and cover glass of a design change example.

  As shown in FIG. 5, a corner portion 60 </ b> C formed by the light incident surface 60 </ b> A and the light emitting surface 60 </ b> B of the prism 60 may be chamfered to include a notch portion 62 formed of a chamfered portion. Since the adhesive 70 can be received by the cutout portion 62 of the prism 60 and the cutout portion 42 of the cover glass 40, the lens barrel 50 and the imaging element substrate 80 are bonded to each other when the prism 60 and the cover glass 40 are bonded. The leakage of the adhesive 70 to the gap G side can be suppressed more effectively.

  In FIG. 5, the notch is provided only on one side (one corner) facing the gap G between the prism 60 and the cover glass 40, but as shown in FIGS. 6 and 7, the prism 60 and the cover glass 40. Notches 62a to 62d and 42a to 42d may be provided on all four sides of the mutually facing surfaces. As shown in FIG. 7, when the prism 60 and the cover glass 40 are bonded, the adhesive 70 accumulates on the four sides, so that a self-alignment effect can be obtained by the surface tension of the adhesive. That is, it is possible to reduce the labor for positioning the minute optical system.

  As shown in FIG. 8, the cutout portion of the cover glass 40 may be a stepped portion 44. Similarly, the notched portion of the prism 60 may be a stepped portion 64. Moreover, as shown in FIG. 9, you may provide the recessed part 46 as a notch in the part which opposes the corner | angular part 60C of the prism 60 of the cover glass 40. As shown in FIG. As shown in FIG. 9, the “corner portion” of the cover glass in the present invention includes an end region on the lens barrel side outside the imaging region and a portion facing the corner portion 60 </ b> C of the prism 60.

  When bonding the cover glass 40 and the prism 60, an adhesive 70 is applied in an amount sufficient to be bonded by the uniform adhesive layer 72 between the one surface 40 </ b> A of the cover glass 40 and the light emitting surface 60 </ b> B of the prism 60. To do. At this time, it is important to control the amount of application so that the amount of the adhesive 70 leaking from one side of the lens barrel side of the interface at the time of bonding is accepted by the notches 42 and 62. . As long as the adhesive 70 does not fill the gap G on the gap G side between the lens barrel 50 and the image pickup device substrate 80, the adhesive 70 may slightly penetrate. Here, a state in which a portion where the lens barrel 50 and the imaging element substrate 80 are connected via an adhesive is formed is considered that the gap G is embedded with the adhesive.

  As in each of the embodiments described above, in an imaging unit having a very narrow gap of 0.1 mm to 0.2 mm between the lens barrel and the imaging element substrate, the gap is embedded by a minute adhesive. Therefore, the effect of suppressing leakage of the adhesive into the gap is extremely high by receiving the surplus adhesive in the cutout portions of the cover glass and the prism.

  If the gap G between the lens barrel 50 and the image pickup device substrate 80 is embedded with an adhesive, the cover glass 40 and the prism 60 are peeled off due to the expansion of the adhesive, the lens barrel, etc. at the high temperature described above. To do. The cover glass 40 and the prism 60 are minute optical systems, respectively, and it is very difficult to control the amount of adhesive.

  Therefore, as shown in FIG. 10, it is preferable that the prism 60 is arranged such that the corner portion 60 </ b> C protrudes outside the outer periphery of the lens barrel 50. By projecting the prism 60 outward from the outer periphery of the lens barrel 50, the gap G between the lens barrel 50 and the imaging element substrate 80 and the bonding state between the prism 60 and the cover glass 40, particularly the notched portion of the adhesive 70. The degree of leakage to 42 and 62 can be easily confirmed. When the image pickup unit is manufactured, after the cover glass 40 and the prism 60 are bonded to each other, the gap G and the connecting portion between the prism and the cover glass are visually observed, and the leaked adhesive 70 does not fit in the notch and the gap. When G is filled, it can be excluded as a defective product.

  Further, since the prism 60 shown in this example is arranged so as to protrude outward from the outer periphery of the lens barrel 50, the prism 60 is made larger in size than the above-described embodiment, and an effective area is secured. doing. When the prism is made large and the notch 62 is provided in the prism 60, the accommodation capacity can be increased, so that leakage of the adhesive 70 to the gap G side can be more effectively suppressed. Can do.

FIG. 11 is a cross-sectional view of an imaging unit 30A that is a modification of the imaging unit 30 shown in FIG. In FIG. 11, the same components as those in FIG.
The imaging unit 30 </ b> A of the present embodiment includes a color filter 90 that is a form of a flat plate optical member at one end on the base end side of the lens barrel 150, and light incident on the prism 60 is incident on the light exit surface 90 </ b> A of the color filter 90. The surface 60A is connected. The light exit slope 90 </ b> A of the color filter 90 and the light incident surface 60 </ b> A of the prism 60 are connected via an adhesive 70.
The color filter 90 is an optical glass filter having a function of transmitting only wavelengths in a desired wavelength range, such as a low-pass filter.

  In this example, the image pickup device substrate 80A includes a silicon substrate 81 provided with the image pickup device 82 and a circuit substrate 83 fixed to the rear end thereof, and does not include the flexible substrate 85. One end 150 </ b> A on the base end side of the lens barrel 150 is arranged to face the side surface 80 </ b> A of the image sensor substrate 80 with a gap G.

  One side of the interface between the prism 60 and the cover glass 40 is disposed facing the gap G. Similarly, one side of the interface between the prism 60 and the color filter 90 is disposed facing the gap G. Yes. The prism 60 and the cover glass 40 are bonded via an adhesive layer 72. Similarly, the prism 60 and the color filter 90 are bonded via an adhesive layer 72.

  A corner portion 90 of the color filter 90 that faces the corner portion 60C of the prism 60 is chamfered to be provided with a notch 92 that is a chamfered portion. The notch 92 accommodates the adhesive 70. The notch 92 provided at the corner of the color filter 90 is not limited to the chamfered portion but may be a step or a recess.

  When the adhesive 70 is embedded in the gap G between the lens barrel 150 and the imaging element substrate 80, the optical filter 90 and the prism 60 are peeled off due to the expansion of the adhesive 70 and the lens barrel 50, or the prism 60 and the cover glass 40. Peeling may occur. However, according to the configuration of this example, when the optical filter 90 and the prism 60 are bonded, the adhesive 70 leaking from one side facing the gap G at the interface is received by the notch 92 and enters the gap G. Leakage can be sufficiently suppressed.

  In each of the above-described embodiments, the cover glass or the color filter has been described as the flat optical member provided with the notch. However, the flat optical member is bonded to the light emitting surface or the incident surface of the prism via an adhesive. There is no particular limitation as long as it is present. It is arranged so that at least one side of the interface between the prism and the flat plate optical member faces the gap between the lens barrel and the imaging device substrate, and excess adhesive leaks from the one side of the interface when the two are bonded. In the configuration, it is only necessary that a notch portion is provided at a corner portion facing the corner portion of the prism of the flat optical member so as to receive the adhesive. By providing the notch, leakage of the adhesive into the gap can be suppressed, and an image sensor unit in which the gap is not embedded with the adhesive can be obtained. By the configuration in which the adhesive is not embedded between the lens barrel and the imaging element substrate, peeling between the prism and the cover glass can be suppressed.

DESCRIPTION OF SYMBOLS 11 Endoscope apparatus 12 Endoscope 13 Control apparatus 14 Light source apparatus 15 Air supply / water supply apparatus 15a Air supply apparatus 15b Washing water tank 16 Insertion part 16a Tip part 16b Bending part 16c Flexible pipe part 17 Operation part 19 Universal cord 20 Monitor 21 Angle Knob 22 Air / Water Supply Button 23 Forceps Port 24 Tip Hard Part 25 Tip Protection Cap 25a Through Hole 30 Endoscope Imaging Unit 30 Imaging Unit 32 Forceps Channel 33 Bending Piece 34 Outer Tube 38 Objective Lens 38A, 38B, 38C Lens 40 Cover glass 40A One side of cover glass 40C Side surface of cover glass 40C Side surface 42 Notch 44 Stepped portion 46 Recess 50, 150 End of lens barrel 50A, 150A One end 60 of base end of lens barrel Prism 60A Light incident surface 60B of prism Light exit surface 62 notch 64 stepped portion 0 adhesive 72 bonding layer 75 side light emitting surface of the 80,80A imaging element substrate 82 image pickup device 83 circuit portion 84 receiving portion 90 color filter 90A color filter

Claims (7)

An objective lens disposed at the distal end of the insertion portion of the endoscope;
A lens barrel holding the objective lens;
A light incident surface connected directly or indirectly to one end of the lens barrel, and a prism having a light exit surface perpendicular to the light incident surface;
A flat optical member having one surface bonded to either one of the light incident surface and the light emitting surface of the prism via an adhesive;
An imaging unit for an endoscope comprising an imaging device substrate disposed to face the light exit surface of the prism;
The lens barrel and the image pickup device substrate have a portion arranged to face each other with a predetermined gap,
One side of the interface between the prism and the flat plate optical member on the corner portion formed by the light incident surface and the light exit surface of the prism faces the gap.
An endoscope imaging unit comprising a notch at a corner of the flat optical member facing the corner of the prism.   The endoscope imaging unit according to claim 1, further comprising a notch at the corner of the prism.   The endoscope imaging unit according to claim 1 or 2, wherein the notch is a chamfer.   The imaging unit for endoscope according to any one of claims 1 to 3, wherein the flat optical member is a cover glass bonded to the light emitting surface of the prism.   4. The endoscope imaging unit according to claim 1, wherein the flat optical member is an optical filter disposed between one end of the lens barrel and the light incident surface of the prism. 5.   The endoscope imaging unit according to any one of claims 1 to 5, wherein the prism is arranged with the corner portion protruding outward from the outer periphery of the lens barrel.   An endoscope in which the endoscope imaging unit according to any one of claims 1 to 6 is mounted on a distal end portion of an endoscope to be inserted into a subject.