JPH10211167A - Tip part for electronic endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the problem of dust falling to the back surface or the like of a first optical member at the time of incorporating an objective optical system and to facilitate assembly by constituting the objective optical system and a solid-state image pickup element in a unit in the one for which the objective optical system and the solid-state image pickup element are incorporated in the tip part main body of an endoscope. SOLUTION: The tip part main body of the endoscope is composed of an electrically insulated plastic material and is connected to the tip of a curved part freely bendably provided on the tip of a thin and long flexible insertion part. Then, on the inner side of an observation window formed on the tip part main body, the unit of an objective lens group 46 and the solid-state image pickup element 10 is disposed. In the unit, the objective lens group 46 is composed by being fixed through a spacer 49 inside a metallic lens frame 47 and a cover glass 46a which is the first optical member of the objective lens group 46 is water-tightly fitted to the front end face part of an insulation ring 51. Also, the solid-state image pickup element 10 is disposed inside a shield pipe 55 so as to pick up endoscope observation images image-formed by the objective lens group 46.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tip of an electronic endoscope in which an endoscope observation image is picked up by a solid-state image sensor.

[0002]

2. Description of the Related Art Generally, at the distal end of an electronic endoscope, an objective lens and a solid-state imaging device are built in a distal end body provided at the distal end of an insertion section, and the objective lens is a lens as one unit. It is attached to the frame.

[0003] A cover glass generally formed of a plane-parallel plate is fitted as a first optical member of the objective lens into an observation window which is a light image entrance window to the objective lens (in some cases, a convex lens or the like). .

[0004]

The observation window to which the cover glass is attached is generally provided on the distal end body. Therefore, at the time of assembly, the lens frame in which the objective lens is incorporated is assembled from the rear into the distal end body with the cover glass attached.

For this reason, it is necessary that dust adheres to the back surface of the cover glass before the lens frame is assembled at a predetermined position in the tip body, and is removed by work from the back surface of the tip body. In many cases, it was very difficult.

Accordingly, the present invention provides an electronic endoscope which can be easily assembled without causing a problem of dust falling on the back surface of the first optical member when the objective optical system is incorporated into the distal end body. It is intended to provide a tip.

[0007]

In order to achieve the above object, the distal end of an electronic endoscope according to the present invention is provided with an objective optical system and a solid state attached to a distal end body provided at the distal end of an insertion section of the endoscope. The objective optical system and the solid-state imaging device are configured as a single unit not including the distal end body at the distal end of the electronic endoscope having the built-in imaging device, and the first optical system of the objective optical system is The member is attached to a member included in the unit.

[0008] The first optical member may be attached to a member located at the forefront of the unit.
The member to which the first optical member is attached may be an electrically insulating member.

The first optical member may be a convex lens such as a plane parallel plate or an aspherical surface, or may be a meniscus lens.

[0010]

Embodiments of the present invention will be described with reference to the drawings. FIG. 2 shows a distal end portion of the insertion section of the endoscope.

The distal end main body 31 is formed of an electrically insulating plastic material, and is connected to a distal end portion of a bending portion 32 which is provided at the distal end of an elongated flexible insertion portion so as to be freely bent by remote control.

The bending portion 32 rotatably connects a number of node rings 33 with rivets 34, and has a mesh tube 35 around its outer periphery.
, And the outer surface thereof is further covered with an outer skin 36 made of a rubber tube or the like. The distal end of the outer cover 36 is tied and joined to the outer peripheral surface of the distal end body 31.
38 is a bending operation wire.

The distal end main body 31 and the curved portion 32 are screwed by a female screw into a pair of metal screw pieces 37 embedded in the recesses of the distal end main body 31 and screwed to the leading end ring 33. It is linked by being done.

The endoscope according to the present embodiment is a so-called forward-looking type endoscope for observing the front.
Are disposed on the distal end surface of the distal end body 31. Observation window 4
The objective lens group 46 and the solid-state image pickup device 10 are arranged inside 1, and they are assembled as a single unit separately from the distal end main body 31 as shown in an enlarged view in FIG. 1.

The objective lens group 46 includes a metal lens frame 4.
It is fixed to the inside 7 by a spacer 49 at a predetermined interval. Reference numeral 45 denotes a brightness stop. An insulating ring 51 made of an electrically insulating plastic material is joined to the outer peripheral portion of the front half of the lens frame 47.

A cover glass 46a, which is a first optical member of the objective lens group 46, is a transparent parallel flat plate.
Are fitted into the front end face portion (observation window 41 portion) of the insulating ring 51 and are joined in a watertight manner. A indicates the optical path of the outermost effective light beam.

The outer peripheral surface of the insulating ring 51 is formed with a hole 5 having a circular cross section formed in the front end portion of the tip end body 31 in parallel with the axial direction.
2 and a sealing O-ring 53 is mounted thereon.

The connecting member 48 fixed to the rear end portion of the lens frame 47 has a horizontally long rectangular outer shape, and a distal end portion of a metal shield pipe 55 is fitted on the outer peripheral portion thereof. Are joined.

The shield pipe 55 is connected to the solid-state imaging device 10.
Is inserted into a rectangular hole 56 that is formed in a tubular shape with a horizontally long rectangular cross section corresponding to the shape of.

In the shield pipe 55, a solid-state image pickup device 1 composed of, for example, a charge-coupled device (CCD) for picking up an endoscope observation image formed by the objective lens group 46 is provided.
0 is fixed with the light receiving surface 11 facing forward.

The light receiving surface 11 of the solid-state imaging device 10 has a horizontally long rectangular shape as shown in FIG. 3, and is arranged at a position where an object is formed by the objective lens group 46. On the front surface of the cover glass 13 stuck on the front surface of the light receiving surface 11, Y
An AG laser light cut filter 58 is attached.

Electronic components 61 for processing signals input to and output from the solid-state imaging device 10 are provided in the shield pipe 55.
Are attached to the wiring board 62 and arranged on the rear side of the solid-state imaging device 10. Then, the signal cable 63 is led backward from there.

Insulating tapes 64 and 65 are wound around the outer peripheral surface of the components arranged in the shield pipe 55 and the outer peripheral surface of the shield pipe 55, respectively, to electrically insulate the shield pipe 55 from the inside and outside. ing.

The solid-state imaging device 10 has a flexible substrate 20 to which TAB (tape auto mating bonding) is applied.
Is attached, and the lead 2 of the flexible substrate 20 is attached.
3 is bent inward, and the wiring board 62 is fixed thereto. Reference numeral 21 denotes a reinforcing plate of the flexible substrate 20, which is formed by an electrically insulating thin plate.
It is arranged between the inner peripheral surface of the shield pipe 55.

As shown in FIG. 1, the unit shown in FIG. 1 in which the objective lens group 46 including the cover glass 46a, the solid-state image pickup device 10, and the like are incorporated as described above penetrates through the distal end main body 31. It is fitted into the formed holes 56 and 52 from the rear (that is, from the bending portion 32 side), and is fixed to the distal end portion main body 31 by a fixing screw (not shown).

Therefore, all the objective lens groups 46 including the cover glass 46a are assembled into the distal end main body 31 in a state where they are assembled in advance as a unit. The problem of dust falling on the back surface of the glass 46a does not occur.

When it is necessary to perform disassembly and repair,
By loosening the fixing screw and pushing the insulating ring 51 backward from the distal end side, the entire unit can be pulled out from the distal end main body 31 in the depth direction. Therefore, the objective lens group 46 can be taken out without having to pull the signal cable 63 or the like from behind, and disassembly and repair can be easily performed.

FIG. 4 is a front view of the distal end surface of the insertion portion (that is, FIG.
FIG. 4 is a front view of the distal end portion main body 31). Reference numerals 1 and 2 denote illumination windows into which concave lenses are fitted, and the emission end faces of the illumination light guide are arranged inside the illumination windows. 3 is a forceps channel outlet, and 4 and 5 are an air supply nozzle and a water supply nozzle.

The cover glass 46a attached to the end surface of the insulating ring 51 is connected to the light receiving surface 11 of the solid-state imaging device 10.
It is formed in a rectangular shape having a shape similar to that described above and having a size that allows all necessary light beams of the objective lens group 46 to pass through and does not allow unnecessary peripheral light beams to pass therethrough.

The present invention is not limited to the above embodiment. For example, as shown in FIG. 5, a convex lens 46b or the like may be used as the first optical member of the objective lens group 46. May be an aspherical lens or a meniscus lens.

[0031]

According to the present invention, the objective optical system and the solid-state imaging device are formed in a single unit not including the tip main body, and the first optical member of the objective optical system is used as a member included in the unit. By mounting, all the objective optical systems including the first optical member are assembled into the distal end main body in a state where they are assembled in advance as a unit. Assembling can be easily performed without causing a problem of dust falling on the back surface or the like.

Further, if the first optical member is pushed from the front end side,
Since the entire unit can be pushed into the back side of the distal end body, the objective optical system can be taken out without pulling the signal cable or the like from the rear, and disassembly and repair can be easily performed.

[Brief description of the drawings]

FIG. 1 is an enlarged side sectional view of a unit in which an objective optical system and a solid-state imaging device according to an embodiment of the present invention are incorporated.

FIG. 2 is a side sectional view of a distal end portion of the electronic endoscope according to the embodiment of the present invention.

FIG. 3 is a front view of a light receiving surface of the solid-state imaging device according to the embodiment of the present invention.

FIG. 4 is a front view of the distal end of the insertion section at the distal end of the electronic endoscope according to the embodiment of the present invention.

FIG. 5 is a front view of a distal end of an insertion portion of a distal end portion of the electronic endoscope according to the second embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 solid-state imaging device 46 objective lens group 46a cover glass (first optical member) 46b convex lens (first optical member) 47 lens frame 51 insulating ring

Claims (7)

[Claims] 1. An electronic endoscope in which an objective optical system and a solid-state image pickup device are incorporated in a distal end body provided at the end of an insertion portion of the endoscope, wherein the objective optical system and the solid-state image pickup device are provided. Wherein the first optical member of the objective optical system is attached to a member included in the unit. 2. The distal end of an electronic endoscope according to claim 1, wherein said first optical member is attached to a member located at the forefront of said unit. 3. The distal end of an electronic endoscope according to claim 1, wherein the member to which the first optical member is attached is an electrically insulating member. 4. The tip of an electronic endoscope according to claim 1, wherein said first optical member is a plane-parallel plate. 5. The tip of an electronic endoscope according to claim 1, wherein said first optical member is a convex lens. 6. The distal end of an electronic endoscope according to claim 5, wherein said convex lens is a lens having an aspherical surface. 7. The tip of an electronic endoscope according to claim 1, wherein said first optical member is a meniscus lens.