JP6517080B2 - Tip structure of a perspective endoscope - Google Patents

Description

  The present invention relates to a distal end structure of a perspective endoscope.

FIGS. 17 to 25 show a perspective endoscope as proposed by the present applicant (Japanese Patent Application Laid-Open No. 2013-230223).
A distal end optical element storage hole 014 extending in the axial direction of the distal end hard portion 012 is formed on the inclined surface 013 provided on the distal end hard portion 012 of the insertion portion 011 of the oblique-viewing endoscope 010. An optical element combination body 015 including a rear group lens barrel 016, a rear group lens 017, an auxiliary frame 018, a cover lens 019, and a prism 020 is inserted into the tip optical element storage hole 014.
The rear group barrel 016 is a cylindrical member made of metal, and includes a front member (intermediate connection cylinder) 016a and a rear member (lens support cylinder) 016b which can be joined to each other. The cross-sectional shape of the front side member 016a is substantially square, and the front and rear ends are open. Further, the front end face of the front side member 016a is constituted by an inclined front end face 016c parallel to the inclined face 013.
The metal auxiliary frame 018 has an inclined plate portion 018a parallel to the inclined surface 013. A cover lens storage hole 018b is formed in the inclined plate portion 018a. The rear half portion of the inclined plate portion 018a constitutes a fitting projection 018c having a smaller cross-sectional shape than the front half portion. The front half of the inclined plate portion 018a constitutes an abutting portion 018d, and the sectional shape of the abutting portion 018d is substantially the same as the inclined front end surface 016c of the front side member 016a. Further, on the left and right sides of the rear surface of the fitting projection 018c, a pair of prism fixing arms 018e extending in a backward direction while being parallel to each other are integrally formed.

In order to assemble the optical element combination 015 from the rear group lens barrel 016, the rear group lens 017, the auxiliary frame 018, the cover lens 019, and the prism 020, first, the prism 020 between the pair of prism fixing arms 018e of the auxiliary frame 018 The cover lens 019 is fitted into the cover lens storage hole 018b. Then, the pair of prism fixing arms 018 e and the prism 020 are fixed with an adhesive, and the cover lens storage hole 018 b and the cover lens 0 19 are fixed with an adhesive. At the same time (or before or after) the mounting operation of the prism 020 and the cover lens 019 to the auxiliary frame 018, a rear group lens 017 consisting of a plurality of lenses is fixedly mounted inside the rear group barrel 016.
Subsequently, an adhesive is applied to the fitting projection 018c of the auxiliary frame 018, and the fitting projection 018c is a front member while inserting the pair of prism fixing arms 018e and the prism 020 into the rear group barrel 016. The front end opening of 016a is fitted into the inside of the front side member 016a, and the rear end face of the contact portion 018d is brought into contact with the inclined front end face 016c of the front side member 016a. Then, the adhesive applied to the fitting projection 018c adheres to the inner peripheral surface of the front end opening of the front side member 016a and solidifies, so the auxiliary frame 018 and the rear group barrel 016 are fixed to each other.

The optical element combination body 015 completed in this manner is inserted into the front end optical element storage hole 014 from the rear end opening (not shown) of the front end optical element storage hole 014 and the cover lens 019 is exposed at the inclined surface 013 It is fixed to the tip optical element storage hole 014.
An imaging element 023 located immediately after the rear lens group barrel 015 is fixed to the tip optical element storage hole 014.
The incident light (observed image) entering the cover lens 019 enters from the incident plane 020a of the prism 020, is reflected twice by the total reflection plane 020b and the inner surface of the incident plane 020a, and then exits from the outgoing plane 020c After passing through 017, an image is formed on the imaging surface of the imaging element 023 and imaged by the imaging element 023.

JP, 2011-115486, A JP, 2013-230223, A

Since the contact portion 018d and the inclined front end surface 016c are inclined (with respect to the surface orthogonal to the axis of the distal end hard portion), when the rear end surface of the contact portion 018d abuts on the inclined front end surface 016c, the inclined front end A gap is likely to be formed between the surface 016c and the four corners of the contact portion 018d.
If gaps are formed at the four corners, the adhesive before solidification applied to the fitting projections 018c may flow from the gaps at the four corners to the front side of the inclined plate portion 018a and adhere to the cover lens 019.

Further, since the diameter of the insertion portion tends to be reduced in recent years, the diameter of the optical element combination 015 is also reduced accordingly.
Therefore, when the front member 016a and the auxiliary frame 018 are manufactured while considering the manufacturing tolerance after reducing the diameter of the optical element combination 015, the space between the fitting projection 018c of the auxiliary frame 018 and the inner peripheral surface of the front member 016a It is easy to make a gap. For example, when the upper portion of the fitting protrusion 018c is brought into contact with the upper portion of the inner circumferential surface of the front side member 016a, a gap is formed between the lower portion of the fitting protrusion 018c and the lower portion of the inner circumferential surface of the front side member 016a (See FIG. 25). Then, the adhesive before solidification applied to the fitting projection 018 c may flow from the lower gap to the front side of the inclined plate 018 a and adhere to the cover lens 019.

  Furthermore, the upper portion of the fitting protrusion 018c of the auxiliary frame 018 is in contact with the upper portion of the inner peripheral surface of the front member 016a and between the lower portion of the fitting protrusion 018c and the lower portion of the inner peripheral surface of the front member 016a. When the auxiliary frame 018 and the front side member 016a are connected in a state where a gap is formed, the lower end of the auxiliary frame 018 centering on the contact portion between the upper portion of the fitting projection 018c and the upper side of the inner peripheral surface of the front side member 016a There is a risk of the part rotating backward (slightly) from the normal position. If such rotation occurs, the upper end of the auxiliary frame 018 will be located slightly ahead of the normal position, so when the optical element combination 015 is attached to the tip optical element storage hole 014, the cover lens The upper end of 019 protrudes forward from the inclined surface 013 of the distal end hard portion 012.

  According to the present invention, when connecting the cover lens and the auxiliary frame supporting the prism to the rear group barrel supporting the rear group lens, a gap is hardly formed between them, and the auxiliary frame and the rear group barrel are regularized. It is an object of the present invention to provide a distal end structure of a perspective endoscope which is easy to fix in position.

  The distal end structure of the perspective endoscope according to the present invention has a distal end optical element storage hole extending in the axial direction in an inclined surface provided so as to be inclined with respect to the axis of the distal end hard portion in the distal end hard portion of the insertion portion. In a tip portion structure of a perspective endoscope having an optical element formed in the tip optical element storage hole, the rear group barrel having both ends opened and inserted into the tip optical element storage hole, and the rear group mirror A rear group lens supported inside the cylinder, and a cover lens accommodation hole located on the same plane as the inclined surface and having a cover lens accommodation hole, which is located in front of the rear group barrel and inserted into the tip optical element storage hole. An auxiliary frame including a pair of prism fixing arms extending toward the rear, a cover lens parallel to the inclined surface fixed to the cover lens receiving hole, and a pair of prism fixing arms And a prism having a sandwich The rear group barrel includes a cylindrical portion whose front surface is a plane orthogonal to the axial direction and whose both ends are open, and a support piece extending in parallel to the axial direction from the front end of the cylindrical portion. And the auxiliary frame contacts the front surface of the tubular portion via an adhesive with the prism fixing arm and the prism positioned in the tubular portion with respect to the axial direction. It is characterized by comprising: a rear end contact surface formed of orthogonal planes; and an outer peripheral contact surface formed on the outer peripheral surface and in contact with the support piece via an adhesive.

  The tip portion structure of the oblique-viewing type endoscope according to the present invention is formed at a portion different from the inclined front end face of the outer surface of the auxiliary frame, and is perpendicular to the rear end contact surface and sandwiching the auxiliary frame For contact with the first jig abutment surface opposite to the piece and the second jig contact surface parallel to the above rear end contact surface and opposite to the above rear end contact surface across the auxiliary frame It can comprise a plane.

  In the tip portion structure of the oblique-viewing endoscope of the present invention, the outer peripheral surface of the auxiliary frame is formed of four faces, and a surface having an opening among the four faces can constitute the outer peripheral side contact surface.

In the present invention, since the rear end contact surface and the outer peripheral contact surface of the auxiliary frame in the mutually orthogonal positional relationship are brought into contact with the front surface and the support piece of the rear group barrel which are in the mutually orthogonal positional relationship (( Even if the manufacturing tolerance of at least one of the rear lens group barrel and the auxiliary frame is large, it is not between the front surface of the rear lens group barrel and the rear end contact surface of the auxiliary frame, and the rear lens group mirror A gap is unlikely to be formed between the support piece of the cylinder and the outer peripheral side contact surface of the auxiliary frame. Therefore, the auxiliary frame and the rear group barrel can be securely fixed via the adhesive. Furthermore, since a gap is difficult to be formed between the auxiliary frame and the rear group barrel, when the auxiliary frame and the rear group barrel are fixed, both are displaced from the normal position (for example, the auxiliary frame with respect to the rear group barrel) There is little possibility of tilting, etc., and it is easy to fix the auxiliary frame and the rear lens group barrel at the regular position.
Further, the front surface of the rear lens group barrel is constituted by a plane orthogonal to the axial direction of the distal end hard portion, and the rear end contact surface which is the rear end surface of the auxiliary frame is constituted by a plane orthogonal to the axial direction It is Therefore, when the front surface of the rear lens group barrel and the rear end contact surface of the auxiliary frame are fixed with an adhesive, the space between the front surface of the rear group lens barrel and the rear end contact surface of the auxiliary frame Between) is difficult to form a gap. Therefore, the adhesive applied between the front surface of the rear lens group barrel and the rear end contact surface of the auxiliary frame hardly flows (through the gap) toward the cover lens and adheres to the cover lens.

BRIEF DESCRIPTION OF THE DRAWINGS It is an external view which shows one Embodiment of the ultrasound endoscope to which this invention is applied. It is an expansion vertical side view of a tip rigid part. It is the perspective view seen from the front slanting upper part of an auxiliary frame. It is the perspective view seen from diagonally above of the back of the auxiliary frame. It is the perspective view seen from the back slanting lower part of an auxiliary frame. It is a rear view of an auxiliary frame. It is the perspective view seen from the front of an intermediate connection pipe. It is the perspective view seen from the front of a back group unit. (A) is a side view of the lens-prism unit in the separated state, and (b) is a side view of the rear-group barrel in the separated state. FIG. 6 is a side view showing the lens prism unit, the intermediate connection cylinder, and the rear unit separately from one another. It is a side view of the completed state of the optical element combination. It is a bottom view of an auxiliary frame. It is a rear view of an auxiliary frame. It is sectional drawing seen from the back of the auxiliary frame and intermediate | middle connection cylinder which are cut and shown in the contact position of an auxiliary frame and the front surface of a cylindrical part. FIG. 15 is a cross-sectional view similar to FIG. 14 when the auxiliary frame is manufactured smaller than that of FIG. 14 (in the case of minus tolerance). It is an expansion vertical side view of a lens prism unit and an intermediate connection pipe in a fixed state. It is an expansion vertical side view similar to FIG. 2 of the conventional endoscope. It is the perspective view which looked at the auxiliary frame of the endoscope of FIG. 17 from the front. It is the perspective view which looked at the auxiliary frame of the endoscope of FIG. 17 from back. It is the perspective view which looked at the auxiliary frame of the endoscope of FIG. 17 from the side. FIG. 18 is a perspective view of the front member of the endoscope of FIG. 17 as viewed from the front. FIG. 18 is a perspective view of the rear side member of the endoscope of FIG. 17 as viewed from the front. FIG. 18 is a side view showing the auxiliary frame, the front side member, and the rear side member of the endoscope of FIG. 17 separately from each other. It is a side view of the completion state of the optical element combination of the endoscope of FIG. FIG. 18 is an enlarged longitudinal sectional side view of the auxiliary frame and the front member in a fixed state of the endoscope of FIG. 17;

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 16. In the following description, the front-rear direction, the vertical direction, and the left-right direction are based on the arrow direction in the drawings.
The ultrasonic endoscope 10 shown in FIG. 1 includes an operation unit 11, an insertion unit 12 extending forward from the operation unit 11, a universal tube 13 extending from the operation unit 11 in a direction different from the insertion unit 12, and ultrasonic image transmission And a tube 14 for providing a perspective view. The ultrasonic image transmission tube 14 is connected to an ultrasonic diagnostic apparatus (not shown), and the universal tube 13 is connected to a processor (image processing apparatus and light source apparatus, not shown). The ultrasonic diagnostic apparatus And the processor are both connected to a CRT monitor (not shown).
The insertion portion 12 is formed with a bending portion 17 that bends in the vertical and horizontal directions in accordance with the rotation operation of the bending operation lever 15 provided in the operation portion 11, and the portion on the proximal end side of the bending portion 17 has its own weight or The flexible tube portion 18 is curved by direct operation of the operator.
As shown in FIG. 1, a portion on the distal end side of the curved portion 17 in the insertion portion 12 is a distal end hard portion 19 made of hard resin. An inclined surface 20 is formed in the rear half of the distal end hard portion 19, and an illumination lens or the like is provided on the inclined surface 20. In the front half of the distal end hard portion 19, an ultrasonic probe 19a located immediately in front of the inclined surface 20 is formed.

In the inclined surface 20 of the distal end hard portion 19, a distal end optical element storage hole 21 penetrating the distal end hard portion 19 in the axial direction is bored. As shown in FIG. 2, at the tip of the tip optical element storage hole 21 is formed a retaining positioning edge 22 so as to protrude inward.
A combination of an auxiliary frame 27, a prism 34, a cover lens 40, a rear lens barrel 42 (intermediate connection cylinder 44 and a lens support cylinder 47), an annular spacer 51, and a rear lens group 52 in the tip optical element housing hole 21. The optical element connector 25 is inserted from the rear end opening (not shown) of the tip optical element storage hole 21.
The metal auxiliary frame 27 is a member whose front shape is substantially square. That is, the outer peripheral surface of the auxiliary frame 27 is composed of four surfaces. The auxiliary frame 27 has a substantially rectangular inclined plate portion 28 inclined in the same direction as the inclined surface 20. A cover lens storage hole 29 (a counterbore hole) and an optical path hole 30 are formed on the inclined front end face 28e which forms the front surface of the inclined plate portion 28 and is parallel (including approximately parallel) to the inclined surface 20. A recess 31 for air layer formation located at the upper part of the optical path hole 30 is provided in the back of the plate portion 28. Side walls 28 a having a substantially triangular shape in side view are respectively provided on the left and right sides of the inclined plate portion 28. The rear end surfaces of the inclined plate portion 28 and the side wall 28a are constituted by a rear end contact surface 32 (see the mesh portion in FIG. 13) which is a plane orthogonal to the longitudinal direction (axial direction of the distal end hard portion 19). . An upper end surface of the inclined plate portion 28 is a first jig abutting flat surface 28 b which is a plane orthogonal to the rear end contact surface 32. Further, a lower end portion of the front surface of the inclined plate portion 28 is a second jig contact flat surface 28 c which is a flat surface parallel to the rear end contact surface 32. Further, the lower end surface of the inclined plate portion 28 and the lower end surfaces of the left and right side walls 28a as a whole have a substantially U-shape and a lower end contact surface 28d (a net shown in FIG. See the line section). A pair of prism fixing arms 33 extending rearward while being symmetrical with respect to the centers of the cover lens storage hole 29 and the optical path hole 30 are integrated in the left and right sides near the rear surface of the rear end contact surface 32. It is formed in
The prism 34 has an incident plane 35 ( total reflection surface on the inner surface ), a pair of side planes 36, a reflection plane (specular reflection surface) 37, and an emission plane 38 in contact with the back surface of the inclined plate portion 28. . The prism 34 is integrated with the auxiliary frame 27 outside the ultrasonic endoscope 10 (tip optical element storage hole 21). That is, the left and right side planes 36 are held between the inner surfaces of the pair of prism fixing arms 33 in a state where the incident plane 35 is in contact with the back surface of the inclined plate portion 28. The rear surface is adhesively fixed, and further, the left and right side plane surfaces 36 and the left and right prism fixing arms 33 are adhesively fixed.
The cover lens 40 having the same cross-sectional shape as the cover lens storage hole 29 and being parallel (including approximately parallel) to the inclined surface 20 has its rear surface in contact with the bottom of the cover lens storage hole 29. It is adhesively fixed to the inner surface. The bonding and fixing operation of the cover lens 40 and the cover lens storage hole 29 is performed after the bonding and fixing operation of the auxiliary frame 27 and the prism 34 outside the ultrasonic endoscope 10 (tip optical element storage hole 21). By fixing the prism 34 and the cover lens 40 to the auxiliary frame 27, the lens prism unit 39 shown in FIG. 10 is completed.

The rear group barrel 42 includes a metal intermediate connection cylinder 44 and a lens support cylinder 47 made of resin.
The intermediate connection cylinder 44 has a cylindrical portion 45 formed of a cylindrical member which is open at both ends with a substantially rectangular cross section. The axis of the cylindrical portion 45 is parallel to the tip optical element storage hole 21. The front surface 45 a and the rear surface of the cylindrical portion 45 are configured by planes orthogonal to the front-rear direction (the axial direction of the distal end hard portion 19). Further, at the lower end of the front surface of the cylindrical portion 45, a support piece 46 formed of a horizontal plate extending forward (orthogonal to the front surface 45a) is provided in a protruding manner.
The lens support cylinder 47 is a cylindrical member having a substantially rectangular cross section as the cylindrical portion 45, and the axis thereof is parallel to the cylindrical portion 45. At a front portion of the lens support cylinder 47, a fitting connection portion 48 having a smaller cross-sectional shape than the rear portion is formed. The mating connection 48 has four planes: an upper plane 48a, a lower plane 48b, a left plane 48c, and a right plane 48d. Further, in the inside of the lens support cylinder 47, an optical element fixing hole 49 having a circular cross section which penetrates the lens support cylinder 47 in the axial direction is formed.
In the optical element fixing hole 49, the annular spacer 51 and the rear group lens 52 are accommodated coaxially in which two annular spacers 51 and two rear group lenses 52 are alternately arranged. It is adhesively fixed to the inner surface. The bonding and fixing operation of the annular spacer 51 and the rear group lens 52 to the lens support cylinder 47 (optical element fixing hole 49) is performed using the prism 34 for the auxiliary frame 27 outside the ultrasonic endoscope 10 (tip optical element storage hole 21). Alternatively, it is performed simultaneously with the bonding and fixing operation of the cover lens 40. By fixing the annular spacer 51 and the rear group lens 52 to the lens support cylinder 47, the rear group unit 53 shown in FIGS. 8 and 10 is completed.

The lens prism unit 39, the intermediate connection cylinder 44, and the rear unit 53 are integrated on the outside of the ultrasonic endoscope 10 (tip optical element storage hole 21). Specifically, an adhesive is applied to the lower contact surface 28d (peripheral contact surface) of the auxiliary frame 27 of the lens prism unit 39 (the meshed area shown in FIG. 12 is the adhesive application region) and the rear end contact After applying the adhesive to the surface 32 (the meshed area shown in FIG. 13 is the application region of the adhesive), the left and right prism fixing arms 33 and the prism 34 are attached to the cylindrical portion 45 from the front end opening of the cylindrical portion 45. The lower end contact surface 28d is placed on the upper surface (the plane orthogonal to the front surface 45a) of the support piece 46 and the rear end contact surface 32 is brought into contact with the front surface 45a of the cylindrical portion 45 (see FIG. 16). At this time, as shown in FIG. 16, a pressing surface T1 and a pressing surface T2 formed of planes orthogonal to each other of the jig T on the first jig abutting flat surface 28b and the second jig abutting flat surface 28c of the auxiliary frame 27. It is possible to carry out while making each surface contact. Since the first jig abutting flat surface 28b of the auxiliary frame 27 and the second jig abutting flat surface 28c are different from the inclined front end face 28e of the inclined plate portion 28 (the surface on which the cover lens storage hole 29 is formed) When the jig T (pressing surfaces T1 and T2) is brought into contact with the first jig abutting flat surface 28b and the second jig abutting flat surface 28c, the inclined front end face 28e (cover lens storage hole) by the jig T There is no risk of damaging the cover lens 40 provided in 29). When the lens prism unit 39 and the intermediate connection cylinder 44 are fixed in this manner, the emission plane 38 of the prism 34 contacts the front surface of the annular spacer 51 on the front side (the peripheral portion of the through hole formed in the center). Furthermore, an adhesive is applied to the outer peripheral surface (upper flat surface 48a, lower flat surface 48b, left flat surface 48c, and right flat surface 48d) of the fitting connection portion 48 of the lens support cylinder 47 of the rear unit 53 and the fitting connection portion The upper surface 48a, the lower surface 48b, and the left surface 48c are fitted to the inner peripheral surface of the cylindrical portion 45 (each facing the four surfaces constituting the rear end inner peripheral surface of the cylindrical portion 45). The adhesive applied to each surface of the right side flat surface 48 d is adhered to the four surfaces constituting the rear end inner peripheral surface of the cylindrical portion 45. The bonding and fixing operation of the lens prism unit 39 and the intermediate connection cylinder 44 and the bonding and fixing operation of the rear unit 53 and the intermediate connection cylinder 44 are performed simultaneously.
The adhesive for fixing the lens prism unit 39 and the intermediate connection cylinder 44, and the optical element combination completed by solidifying the adhesive for fixing the rear group unit 53 and the intermediate connection cylinder 44 Is inserted into the inside of the front end optical element storage hole 21 from the rear end opening of the front end optical element storage hole 21, and the front end portion of the inclined plate portion 28 is abutted against The body 25 is adhesively fixed to the inner surface of the tip optical element storage hole 21. Then, as shown in FIG. 2, the inclined front end face 28 e of the inclined plate portion 28 is located on the same plane as the front surface of the inclined surface 20 (including approximately on the same plane), and the cover lens 40 is exposed on the front surface of the inclined surface 20. .
When the optical element combination 25 is fixed to the distal end optical element storage hole 21, the imaging element 55 provided with the image signal cable 56 is inserted into the distal end optical element storage hole 21 from the rear end opening of the distal end The lens holder 55 is fixed to the tip optical element storage hole 21 in a state of being positioned immediately after the lens support cylinder 47.

Incident light (observed image) that has entered the cover lens 40 of the ultrasonic endoscope 10 passes through the optical path hole 30 and enters the inside of the prism 34 from the outer surface of the incident plane 35 and is reflected on the reflection plane (mirror reflection surface) 37 and The light is reflected twice by the inner surface (total reflection surface) of the entrance plane 35 and then emitted backward from the exit plane 38, passes through the annular spacer 51 and the rear lens group 52, and forms an image on the imaging plane of the imaging device 55. Image data picked up by the image pickup device 55 is sent to the processor via the image signal cable 56, subjected to image processing by the processor and displayed on the CRT monitor.

The ultrasonic endoscope 10 configured as described above has the rear end contact surface 32 of the auxiliary frame 27 in the positional relationship orthogonal to each other with respect to the front surface 45a of the cylindrical portion 45 and the support piece 46 in the positional relationship orthogonal to each other. Since the lower end contact surfaces 28d are in contact with each other (since they are not fitted in), even if the manufacturing tolerances of the intermediate connection cylinder 44 and the auxiliary frame 27 are large, the front surface 45a of the cylindrical portion 45 and the back of the auxiliary frame 27 A gap is unlikely to be formed between the end contact surfaces 32 and between the support piece 46 of the intermediate connection cylinder 44 and the lower end contact surface 28 d of the auxiliary frame 27. That is, FIG. 14 shows adhesion between the rear end contact surface 32 of the inclined plate 28 and the front surface 45a of the cylindrical portion 45 when the actual dimensions of the auxiliary frame 27 and the intermediate connection cylinder 44 (cylindrical portion 45) are very close to the design dimensions. A region (hatched portion; an imaginary line shows the inner peripheral side edge of the front surface 45a), and FIG. 15 shows the case where the actual dimension of the auxiliary frame 27 in the vertical direction deviates relatively (relatively) from the design dimension The bonding area (hatched portion; phantom line is the inner peripheral side edge of the front surface 45a) of the bonding surface of the rear end contact surface 32 of the inclined plate portion 28 and the front surface 45a of the cylindrical portion 45. As is apparent from FIGS. 14 and 15, in either case, a bonding area between the rear end contact surface 32 of the inclined plate portion 28 and the front surface 45a of the cylindrical portion 45 is sufficiently secured. Therefore, the auxiliary frame 27 and the intermediate connection cylinder 44 can be securely fixed.
Moreover, since it is difficult to form a gap between the front surface 45a of the cylindrical portion 45 and the rear end contact surface 32 of the auxiliary frame 27, and between the support piece 46 of the intermediate connection cylinder 44 and the lower contact surface 28d of the auxiliary frame 27, When the auxiliary frame 27 and the intermediate connection cylinder 44 are fixed, there is little possibility that the both are displaced from the normal position (for example, the auxiliary frame 27 is inclined with respect to the intermediate connection cylinder 44), and the auxiliary frame 27 and the intermediate connection cylinder 44 It is easy to fix at the regular position.
Further, among the four surfaces constituting the outer peripheral surface of the auxiliary frame 27, the lower surface (lower end contact surface 28d) having the opening is closed by the support piece 46. Therefore, an adhesive for fixing the optical element combination 25 to the inner surface of the distal end optical element storage hole 21 flows from the lower surface (lower end contact surface 28d) side of the auxiliary frame 27 into the inside of the auxiliary frame 27, and the prism 34 etc. There is no risk of sticking to
Further, the front surface 45a of the cylindrical portion 45 is constituted by a plane orthogonal to the longitudinal direction (axial direction of the distal end hard portion 19), and the rear end contact surface 32 of the auxiliary frame 27 is orthogonal to the axial direction It consists of a plane. Therefore, when the front surface 45a of the cylindrical portion 45 and the rear end contact surface 32 of the auxiliary frame 27 are fixed with an adhesive, the space between the front surface 45a of the cylindrical portion 45 and the rear end contact surface 32 of the auxiliary frame 27 ( For example, a gap is unlikely to be formed between the four corners of the two. Therefore, the adhesive applied between the front surface 45a of the cylindrical portion 45 and the rear end contact surface 32 of the auxiliary frame 27 is likely to flow (through the gap) to the front side of the inclined plate portion 28 and adhere to the cover lens 40 Absent.

  Furthermore, the optical element assembly 25 is a step of simultaneously assembling the lens prism unit 39 and the rear group unit 53, bonding and fixing the lens prism unit 39 and the intermediate connection cylinder 44, and The optical element bonded body 25 can be assembled in a short time because it can be assembled in two steps of simultaneously performing the adhesive fixing operation of the rear group unit 53 and the intermediate connection cylinder 44.

As mentioned above, although this invention was demonstrated using the said embodiment, this invention can be implemented, giving various deformation | transformation.
For example, the intermediate connection cylinder 44 and the lens support cylinder 47 may not be separate bodies, and both may be configured as an integrally molded article made of metal or resin.
In addition, the cross-sectional shapes of the inclined plate portion 28 of the auxiliary frame 27, the fitting connection portion 48 of the lens support cylinder 47, and the internal hole of the cylindrical portion 45 may not be the above-mentioned ones. It may have a shape (for example, a pentagon or the like).
An outer peripheral side contact surface (lower end contact surface 28d) is provided on a portion of the outer peripheral surface of the auxiliary frame 27 corresponding to the support piece 46 with the support piece 46 of the intermediate connection cylinder 44 protruding on the side or upper portion of the cylindrical portion 45 A corresponding surface may be formed, and the support piece 46 and the outer peripheral side contact surface may be fixed by adhesion.
Further, the optical disc can be inserted from the front end opening of the distal end optical element storage hole 21 into the distal end optical element storage hole 21 by omitting the securing positioning edge 22 from the distal end hard portion 19.
Furthermore, the present invention may be applied to a perspective endoscope that does not have the ultrasound probe 19a.

10 Ultrasound endoscopy (oblique view type endoscope)
11 Operation part 12 Insertion part 13 Universal tube 14 Tube 15 for ultrasonic image transmission Curved operation lever 17 Curved part 18 Flexible tube part 19 Tip hard part 19a Ultrasonic probe 20 Inclined surface 21 Tip optical element storage hole 22 Retaining positioning edge 25 Optical element combination body 27 Auxiliary frame 28 Inclined plate portion 28a Side wall 28b First jig abutment plane 28c Second jig abutment plane 28d Lower end contact surface (peripheral side contact surface)
28e Inclination front end face 29 Cover lens housing hole 30 Optical path hole 31 Air layer forming concave part 32 Rear end contact surface 33 Prism fixed arm 34 Prism 35 Incident plane 36 Side plane 37 Reflection plane (mirror reflection surface)
38 Emitting plane 39 Lens prism unit 40 Cover lens 42 Rear group barrel 44 Intermediate connection cylinder 45 Tubular portion 45a Front 46 Support piece 47 Lens support cylinder 48 Fitting connecting portion 48a Upper plane 48b Lower plane 48c Left plane 48d Right plane 49 Optical element fixing hole 51 Annular spacer 52 Rear group lens 53 Rear group unit 55 Image sensor 56 Cable for image signal T Jig T1 T2 Holding surface

Claims (3)

A distal end optical element storage hole extending in the axial direction is formed in an inclined surface provided to be inclined with respect to the axis of the distal end hard portion in the distal end hard portion of the insertion portion, and the optical element is accommodated in the distal end optical element storage hole In the distal end structure of the oblique view endoscope,
A rear group lens barrel inserted into the distal end optical element storage hole and open at both ends;
A rear group lens supported inside the rear group barrel;
An inclined front end face of the rear end lens element holding hole located on the front of the rear group barrel and located on the same plane as the inclined surface and having a cover lens holding hole, and the rear, An auxiliary frame comprising a pair of extending prism fixing arms;
A cover lens parallel to the inclined surface fixed to the cover lens receiving hole;
A prism held by a pair of the prism fixing arms;
Equipped with
The above rear group barrel is
A cylindrical portion whose front surface is a plane orthogonal to the axial direction and whose both ends are open;
A support piece extending in parallel with the axial direction from the front end of the cylindrical portion to the front,
Have
The above auxiliary frame is
A rear end contact surface, which is a plane orthogonal to the axial direction, contacts the front surface of the cylindrical portion through an adhesive in a state where the prism fixing arm and the prism are positioned in the cylindrical portion. When,
An outer peripheral side contact surface formed on the outer peripheral surface and in contact with the support piece via an adhesive;
And a tip portion structure of the perspective endoscope. In the distal end structure of a perspective endoscope according to claim 1,
For contact with a first jig, which is formed at a position different from the inclined front end face of the outer surface of the auxiliary frame, and is orthogonal to the rear end contact surface and opposite to the support piece across the auxiliary frame A tip portion structure of a perspective endoscope including a second jig abutting flat surface which is parallel to the plane and the rear end contact surface and opposite to the rear end contact surface across the auxiliary frame. In the tip portion structure of a perspective endoscope according to claim 1 or 2,
The outer peripheral surface of the auxiliary frame consists of four faces,
The tip portion structure of the oblique-viewing endoscope in which the surface having the opening portion among the four surfaces constitutes the outer peripheral contact surface.

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