JP3380140B2 - Endoscope objective drive mechanism - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an objective drive mechanism for an endoscope having functions such as focusing or zooming.

[0002]

2. Description of the Related Art In order to perform focusing, zooming or the like in an endoscope, it is necessary to remotely move an objective optical system portion built in the tip of an insertion portion in the axial direction.

In order to observe the lesion area precisely, it is desirable to be able to make a close-up magnification observation (so-called macro observation). For that purpose, the objective lens and the image formed by the objective lens are received. The image receiving portion of the image transmitting means for transmitting is moved in the axial direction by remote operation from the hand side.

[0004]

As with all lenses, the objective lens of an endoscope is inevitably subject to a processing error in wall thickness during manufacturing, and the objective lens of an endoscope having a diameter of only a few millimeters. In the case of a lens, the influence of its processing error is large.

Even so, in the case of a general endoscopic observation level, even if there is a processing error, it does not matter so much. However, at the close-up magnifying observation level as described above, the influence of the lens processing error is greatly amplified, so that actual damage such as focusing failure may occur.

Therefore, the present invention provides an objective driving mechanism for an endoscope that can obtain a clear focused endoscope observation image at a close-up magnification observation level even if there is a processing error in the objective lens. To aim.

[0007]

In order to achieve the above object, an objective driving mechanism for an endoscope according to the present invention provides an objective lens built in a distal end of an insertion portion and an image formed by the objective lens. An objective driving mechanism of an endoscope, wherein an image receiving unit of an image transmitting unit that receives and transmits an image can be moved in an optical axis direction by remote operation from a hand side, in an objective driving mechanism of the endoscope, It is characterized in that the position can be finely adjusted in the optical axis direction during assembly.

It should be noted that some of the plurality of objective lenses constituting the objective optical system can be moved in the optical axis direction by the remote operation, and the positions of the some lenses are slightly moved in the axial direction during assembly. It may be adjustable.

Then, the objective lens and the image receiving portion of the image transmitting means are moved in the axial direction by the remote operation to obtain a close-up magnification observation state, and the fine adjustment can be performed in the close-up magnification observation state. I hope I can.

Further, the lens barrel to which the finely adjusted lens is attached is screwed and fixed to a frame body which is driven forward and backward in the optical axis direction by the remote operation, and the screw is loosened to loosen the lens. The fine adjustment may be performed by slightly moving the tube in the optical axis direction and then tightening the screw.

In that case, it is preferable that a hole for inserting a rod member for finely moving the lens barrel in the optical axis direction from the outside is formed in the frame body, and a tool for rotating the screw is inserted from the outside. It is preferable that a hole for this and a hole for inserting a rod member for finely moving the lens barrel in the optical axis direction from the outside are formed in a member around the frame body.

Further, it is preferable that a groove for engaging the tip of a rod member for finely moving the lens barrel in the optical axis direction is formed on the outer peripheral surface of the lens barrel. Note that either one or both of focusing and zooming may be performed by moving the objective lens and the image receiving unit of the image transmitting unit.

[0013]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described with reference to the drawings. FIG. 2 shows the entire configuration of the endoscope,
The operation portion 2 is connected to the proximal end of the flexible tubular insertion portion 1, and the bending portion 4 formed at the distal end portion of the insertion portion 1 is rotated by operating the bending operation knob 3 provided on the operation portion 2. ,
It can be bent in any direction and at any angle.

A tip body 10 having an objective optical system and the like built therein is connected to the tip of the bending portion 4. In addition, a treatment instrument insertion port 5 that is an entrance of a treatment instrument insertion channel inserted and arranged in the insertion portion 1 is provided in the vicinity of a connecting portion between the insertion portion 1 and the operation portion 2 so as to project. Reference numeral 6 is an optical system operation lever for performing focusing or zooming operation.

A connector 8 is connected to the tip of a flexible connecting tube 7 connected to the rear part of the operation section 2, and this connector 8 supplies the illumination light to a light guide fiber bundle for illumination and the tip thereof. It is connected to a light source device and a video processor (not shown) for processing a video signal captured by a solid-state image sensor built in the main body 10.

FIG. 3 is a front view of the tip portion main body 10,
1 is an observation window for taking in an observation image, 12 is an illumination window for emitting illumination light for illuminating a subject, 13 is an outlet of a treatment instrument insertion channel, and 14 and 15 are air supply nozzles and water supply nozzles. .

FIG. 4 is a side sectional view of the distal end portion of the insertion portion 1 in a section passing through the center lines of the observation window 11 and the illumination window 12, FIG. 5 is a VV sectional view thereof, and 4 and 10 are It is the bending portion and the tip portion main body described above.

A concave lens 17 for widening the light distribution angle of the illumination light is fitted in the illumination window 12, and the exit end of the light guide fiber bundle 18 is arranged inside thereof. A cover lens 20, which is the first lens of the objective optical system, is fitted into the observation window 11, and an objective lens group 21, a solid-state image sensor 24, and the like are arranged inside the cover lens 20. Two
2 is a YAG laser cut filter, and 23 is a cover glass.

The skeleton of the curved portion 4 is formed by rotatably connecting a plurality of node rings, and the most advanced node ring 4a is placed on the outer peripheral surface of the rear end portion of the tip body 10. It is fitted and connected and fixed by the fixing screw 4b.

Reference numeral 4c denotes a screw piece arranged in a recess formed in the tip end main body 10 for screwing the fixing screw 4b, 4d denotes a bending operation wire, and 4e denotes a stretchable rubber outer tube. is there.

FIG. 7 is an enlarged view showing the configuration around the objective optical systems 20 and 21 and the solid-state image pickup device 24 in a normal observation state, and FIGS. 6 and 8 show a VI-VI section and a VIII-VIII section. ing. However, in FIG.
Lens barrel fixing screws 80 and the like which are not on the VIII cross section are also shown together.

A fixed inner cylinder 28 is fitted to a fixed outer cylinder 27 fitted and fixed in a hole formed in the tip end main body 10 in the axial direction.
The (fixed cylinder) is directly fitted on the rear side as shown in FIG. 6 and fixed by the fixing screw 29, and both are fixed on the front side.
A space ring 30 is interposed and fixed between 7, 28,
A constant gap is secured between the two members 27 and 28 over the entire length excluding both ends.

The cover lens 20 is watertightly caulked and fixed to the tip of the fixed inner cylinder 28, and the front lid 31 is joined to the space ring 30 so as to close the space between the side surface of the cover lens 20 and the tip end main body 10. ing.

The gap between the front lid 31 and the side surface of the cover lens 20 is filled with defoamed epoxy adhesive, and the fitting surface between the front lid 31 and the tip body 10 is for sealing. An O-ring 32 is attached.

In the fixed inner cylinder 28, an objective frame 34 to which the objective lens group 21 is attached, and a solid-state image pickup device 24 for picking up an endoscopic observation image formed by the objective optical systems 20 and 21 are attached. The image receiving part frame 35 is inserted so as to be movable back and forth independently in the axial direction. 33 is an O-ring.

The objective lens group 21 is assembled in the lens barrel 36 and fixed by caulking.
Is inserted into a hole penetrating the objective frame 34 through the center of the optical axis and is pressed and fixed to the objective frame 34 by the lens barrel fixing screw 80.

Therefore, by temporarily loosening the lens barrel fixing screw 80, the position of the lens barrel 36 in the optical axis direction can be finely adjusted. On the outer peripheral surface of the lens barrel 36,
A circumferential groove 81 with which a tip of an adjustment rod 202, which will be described later, which is a tool for finely moving the lens barrel 36 in the optical axis direction, engages is formed.

Reference numeral 37 is a light-shielding mask for cutting unnecessary ambient light. The aperture stop is arranged on the front end surface of the objective lens group 21. A first compression coil spring 47 is interposed between the objective frame 34 and the image receiving unit frame 35 to urge the two in a direction away from each other, thereby preventing rattling.

The solid-state image pickup device 24 is fixed to the tip of a flexible substrate 44 such as a TAB (tape auto mating bonding) substrate, the cover glass 23 is joined to the front end face of the solid-state image pickup device 24, and YAG is used. The laser cut filter 22 is joined to the front end surface of the cover glass 23.

In the flexible substrate 44, the solid-state image pickup device 24 is provided.
The buffer board 43 on which electronic components constituting the drive circuit of FIG.
5 is pulled out.

A thin electrically insulating tape 38 is continuously wound on the outer peripheral surfaces of the cover glass 23, the solid-state image pickup device 24, and the flexible substrate 44 to form a shield tube made of a conductive tube. 40 is fitted on the outside thereof. The shield wire of the signal cable 45 is connected to the shield tube 40.

The tip of the shield tube 40 has a solid-state image pickup device 24.
Since it is located in the middle of the side surface of the insulating tape 38, the outer surface of the insulating tape 38 is filled with defoamed electrically insulating epoxy adhesive 41 from that position to the tip of the cover glass 23.

An insulating tape 39 is further continuously wound from that portion to the outer circumference of the shield cylinder 40, so that the electric insulation between the shield cylinder 40 and the image receiving portion frame 35 is ensured. Reference numeral 46 is a silicon-based adhesive that is filled on the rear end side in order to prevent dust from entering the image receiving portion frame 35.

The shield tube 40, in which the solid-state image pickup device 24 and the electronic circuit are housed in this way, is pressed and fixed by the fixing screw 42 screwed into the image receiving portion frame 35. This fixing screw 42 is temporarily loosened during focus adjustment in a normal observation state, and further switched to a close-up magnifying observation state described later to check the focus. Fix to 35.

However, since the insulating tape 39 is interposed between the tip surface of the fixing screw 42 and the outer peripheral surface of the shield cylinder 40, the electric insulation between the image receiving frame 35 and the shield cylinder 40 is maintained. Has been secured.

When the focus is confirmed by switching to the close-up magnifying observation state, if the focus state is poor, the position of the lens barrel 36 in the optical axis direction is finely adjusted, which will be described later.

On the outer peripheral surface of the fixed inner cylinder 28, a cylindrical cam cylinder 50 having first, second and third cam grooves 51, 52, 53 is fitted so as to be rotatable about its axis. And
A slide cylinder 55 that is driven by the operation wire 25 and slides in the axial direction is arranged at a position surrounding the cam cylinder 50.

The tip of the operation wire 25 is passed through a hole formed in the slide cylinder 55, and the retaining ring 5 is attached to the tip.
7 is fixed. The slide cylinder 55 is driven to slide to the right in FIG. 7 by the operation of operating the optical system operation lever 6 and pulling the operation wire 25 from the operation section 2 side.

Then, the operation wire 25 is moved in the opposite direction (ie,
When moved to the front), the urging force of the second compression coil spring 58 arranged so as to surround the outer circumference of the fixed inner cylinder 28 causes it to move as shown in FIG.
In, the slide cylinder 55 is slid to the left.
The biasing force of the second compression coil spring 58 is set to be stronger than the biasing force of the first compression coil spring 47 in the normal observation state.

Reference numerals 62 and 63 are double-structured guide tubes for guiding the operation wire 25 in the insertion section 1, and are composed of a flexible tube 62 on the inner side and a closely wound coil pipe 63 having a rectangular cross section on the outer side. , Is fixed to the connection pipe 61 that is fixed to the fixed outer cylinder 27 by soldering. The flexible tube 62 has a function of preventing the lubricant applied to various internal components in the insertion portion 1 from entering.

A first pin 65, whose tip is movably fitted to the first cam groove 51 formed in the cam barrel 50, is screwed into the slide barrel 55 so as to project inward. It is fixed.

A second pin 66, whose head engages with the second cam groove 52, is screwed and fixed to the objective frame 34 so as to project outward, and the second frame 66 is fixed to the image receiving unit frame 35. The third pin 67 whose head is engaged with the third cam groove 53 is screwed and fixed in a state of protruding outward.

The fixed inner cylinder 28 has a second pin 66.
The straight grooves 68 and 69 through which the third pin 67 passes are formed in a direction parallel to the axis. Further, since the head portion of the second pin 66 and the third pin 67 engages with the second cam groove 52 and the third cam groove 53, there is a slit groove for engaging the tip of the driver during assembly. , Is formed by a half-moon-shaped depression that is not exposed on the side surface.

FIG. 9 shows the first to third cam grooves 51, 5
It is a development view showing the engagement state of 2,53 and the 1st thru / or the 3rd pin 65,66,67, and each pin 65,66,67.
Is in the position of the normal observation state shown in FIGS.

The angle θ formed by the first cam groove 51 with respect to the axial direction of the cam barrel 50 (that is, the optical axis direction) is in the range of 10 ° to 45 ° so that a smooth operation can be performed with a small amount of operation force. Is desirable. In this embodiment, θ≈30 °
Is set to.

When the operating wire 25 is pulled by operating the optical system operating lever 6 of the operating portion 2 from this normal observation state, the slide cylinder 55 resists the urging force of the second coil spring 58, as shown in FIG. And rearward (right side in Fig. 10)
The cam barrel 50 is rotationally driven about the axis by the engagement of the first cam groove 51 and the first pin 65 that slides to and moves with it. Its rotation range is 90 °.

When the cam barrel 50 rotates about the axis, the second and third pins 66 and 67 engaging with the second and third cam grooves 52 and 53 formed in the cam barrel 50 move in the axial direction. And the objective frame 34 is forward (left in FIG. 10).
The image receiving portion frame 35 slides rearward (to the right in FIG. 10) while sliding to the right.

The length of the first cam groove 51 is the same as that of the cam barrel 5.
The rotation angle of 0 is exactly 90 °, but the second and third
Both end portions of the cam grooves 52 and 53 when the cam barrel 50 is rotated 90 ° are formed longer than the first cam groove 51.

As a result, when the operation wire 25 is moved forward and backward to rotate the cam barrel 50, the first pin 65 protruding from the slide barrel 55 moves along the first cam groove 51 to move the first pin 65. By contacting the end of the cam groove 51 of the first cam groove 51, the cam barrel 50 cannot rotate any more.
The first pin 65 engaged therewith serves as a stopper for restricting the rotation range of the cam barrel 50.

FIG. 11 shows the engagement state of the first to third cam grooves 51, 52, 53 and the first to third pins 65, 66, 67 with the cam barrel 50 rotated by 90 °. FIG. 1 is a development view, and FIG. 1 shows a cross section taken along line I-I in FIG. 10. In this state, the objective lens group 21 moves forward and the solid-state image sensor 24 moves backward without the cover lens 20 moving.

As a result, zooming is performed. For example, during normal observation, the viewing angle is 120 ° and the observation distance is 5 to 10.
What was in the range of 0 mm became a microscope-like close-up magnified observation state with a viewing angle of 40 ° and an observation distance of 2 to 4 mm.

Then, if the optical system operating lever 6 is stopped at an arbitrary intermediate position, the objective frame 34 and the image receiving frame 35, which are driven via the operating wire 25 and the slide cylinder 55, stop at an intermediate position in the moving range. Thus, the observation can be performed at any magnification between the normal observation state and the close-up magnification observation state.

Reference numerals 201 and 202 shown in FIG. 1 denote a driver and an adjusting rod used for adjusting focus adjustment at the time of assembly. When the focus state is not good in the close-up magnifying observation state shown in FIG. Driver 2
The lens barrel fixing screw 80 is loosened with 01, the lens barrel 36 is finely moved in the optical axis direction with respect to the objective frame 34 with the adjusting rod 202, and the lens barrel fixing screw 80 is tightened at the position where the focus state becomes good. The lens barrel 36 is fixed to the objective frame 34.

A work hole 82 for inserting the adjusting rod 202 from the outside is formed in the objective frame 34 in a direction different from the position of the lens barrel fixing screw 80.
The circumferential groove 81 for engaging the tip of the
It is formed on the outer peripheral surface of the lens barrel 36 so as to be exposed in the depth of 2.

Further, the fixed inner cylinder 28, the cam cylinder 50, and the fixed outer cylinder 27 are provided with working holes 83 to 88 for passing the driver 201 and the adjusting rod 202. As shown in FIG. 1, these working holes 83 to 88, including the working hole 82 formed in the objective frame 34, allow the driver 201 and the adjustment rod 202 to pass from the outside in the close-up magnifying state. It is formed in a positional relationship that communicates with the state.

The present invention is not limited to the above embodiment, and for example, only focusing may be performed, or both focusing and zooming may be performed.

[0057]

According to the present invention, the objective lens and the image receiving portion of the image transmitting means can be moved in the direction of the optical axis by remote control from the hand side, and the position of the objective lens can be adjusted during the assembly. By enabling fine adjustment in the axial direction, a clear endoscopic observation image with focus at the close-up magnification observation level can be obtained even if there is a processing error in the objective lens, and product quality is improved. It can be greatly stabilized.

[Brief description of drawings]

1 is a cross-sectional view taken along the line I-I in FIG. 10 according to the exemplary embodiment of the present invention.

FIG. 2 is a side view showing the overall configuration of the endoscope according to the embodiment of the present invention.

FIG. 3 is a front view of the tip of the insertion portion of the endoscope according to the embodiment of the present invention.

FIG. 4 is a side sectional view of the tip of the insertion portion of the endoscope according to the embodiment of the present invention.

5 is a sectional view taken along line VV in FIG. 4 of the exemplary embodiment of the present invention. FIG.

FIG. 6 is a sectional view taken along line VI-VI in FIG. 7 according to the embodiment of the present invention.

FIG. 7 is an enlarged side sectional view of an objective optical system portion in a normal observation state according to the embodiment of the present invention.

8 is an embodiment of the present invention, VIII-VIII in FIG. 7
FIG.

FIG. 9 is a development view showing the engagement state of the cam groove and the pin in the normal observation state according to the embodiment of the present invention.

FIG. 10 is an enlarged side sectional view of an objective optical system portion in a close-up magnifying observation state according to the embodiment of the present invention.

FIG. 11 is a development view showing the engagement state of the cam groove and the pin in the close-up magnifying observation state according to the embodiment of the present invention.

[Explanation of symbols]

1 Insert 6 Optical system operation lever 20 cover lens 21 Objective lens group 24 Solid-state image sensor 25 operation wire 34 Objective frame 35 Image receiving part frame 36 lens barrel 50 cam barrel 80 Lens barrel fixing screw 81 circumferential groove 82 Working hole 83-88 Working hole 201 driver 202 adjusting rod

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Claims (5)

(57) [Claims] 1. A objective driving mechanism of the endoscope to be able to move in the optical axis direction of the objective lens incorporated in the distal end of the insertion portion is attached to the lens barrel by remote control from the proximal met Te, the lens barrel, forward and backward in the optical axis direction by the remote control
To the fixing screw that can be loosely attached to the driven frame
It is pressed and fixed to the frame body, and the fixing screw is loosened.
Then move the lens barrel slightly with respect to the frame in the optical axis direction.
By tightening the fixing screw were allowed, odor that the position of the objective lens in the above mechanism, was it possible to finely adjust the optical axis direction during assembly
The rod that slightly moves the lens barrel in the optical axis direction from the outside.
A hole for inserting is formed in the frame body, and the frame body
Holes for inserting the above rods from the outside into the members around
And insert the tool that rotates the fixing screw from the outside.
And a hole for the purpose, and when the objective lens is in the close-up magnifying observation position,
In order to insert the bar from the outside, the frame and the circumference of the frame
When the holes made in each of the surrounding members are in communication with each other
At the same time, in order to insert the above tool from the outside,
Position where holes drilled in surrounding members lead to the fixing screws
Objective driving mechanism of the endoscope, characterized in that it has to come in. 2. A part of a plurality of objective lenses constituting an objective optical system can be moved in the optical axis direction by the remote operation, and the position of the part of the lenses is fine in the axial direction during assembly. The objective drive mechanism for an endoscope according to claim 1, which is adjustable. 3. A close-up magnifying observation state is obtained by moving the objective lens and the image receiving portion of the image transmitting means in the axial direction by the remote operation, and the fine adjustment can be performed in the close-up magnifying observation state. The objective drive mechanism for an endoscope according to claim 1 or 2, which is capable. 4. The endoscope according to claim 1, 2 or 3, wherein a groove is formed on the outer peripheral surface of the lens barrel for engaging the tip of a rod member for finely moving the lens barrel in the optical axis direction. Objective drive mechanism. By the movement of wherein receiving portion of the objective lens and the image transmission means, the focusing and to the claims 1 performed either or both zooming endoscope according to any one of claims 4 objective Drive mechanism.