JP3803175B2 - Endoscope cam mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cam mechanism used for a drive mechanism incorporated in an endoscope.
[0002]
[Prior art]
A so-called cam mechanism in which a pin is engaged with a cam groove is used in a portion where the rotational motion needs to be converted into linear motion or the linear motion needs to be converted into rotational motion.
[0003]
The pin used in such a cam mechanism is often screwed and fixed to the movable member, and as shown in FIG. 14, to engage the tip of a tool (driver) that performs screwing work during assembly. In addition, a slot 90 a is formed in the head of the pin 90.
[0004]
[Problems to be solved by the invention]
However, since such a pin 90 has both ends of the slot 90a appearing on the outer peripheral surface of the head, in a mechanism in which the head of the pin 90 engages with the cam groove, the end of the slot 90a is at the end. The part may slide with the cam surface, which may cause roughness in the operation of the mechanism.
[0005]
Therefore, as shown in FIG. 15, it is conceivable to reduce the diameter of the head portion where the slit groove 90a is formed so that the slit groove 90a does not contact the cam groove. Since the cam mechanism increases in size due to the increase in the height H of 90, it is not suitable for use in the distal end of the insertion portion of the endoscope.
[0006]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an endoscope cam mechanism that can obtain a smooth operation and can be made compact.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the cam mechanism of the endoscope according to the present invention converts the rotational motion into a linear motion by engaging the head of a pin screwed and fixed to the movable member into the cam groove, or performs the linear motion. In an endoscope cam mechanism that is converted into a rotational motion, a slot groove for engaging the tip of a tool when the pin is screwed into the movable member is not exposed to the outer peripheral surface of the pin. It was formed in the head of the said pin.
[0008]
Note that the slit groove may be formed by a half-moon-shaped depression.
Further, the cam groove is formed in a cam cylinder disposed in the distal end of the insertion portion so as to be rotatable around an axis, and the cam cylinder is rotationally driven via an operation wire that moves in the axial direction by remote operation. The movable member may be driven in the axial direction via the pin engaged with the cam groove.
[0009]
The movable member may be one or both of an objective frame to which an objective optical system is attached and an image receiving part frame to which an image receiving unit of an image transmission unit is attached, and at least the objective frame and the image receiving part frame. Either one or both of focusing and zooming may be performed by one movement.
[0010]
[Form of the present invention]
Embodiments of the present invention will be described with reference to the drawings.
FIG. 2 shows the overall 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 the operation portion 2. By rotating the bending operation knob 3 provided on the head, it is possible to bend it in an arbitrary direction by an arbitrary angle.
[0011]
A distal end body 10 incorporating an objective optical system and the like is connected to the distal end of the bending portion 4. In addition, a treatment instrument insertion port 5 that is an entrance of a treatment instrument insertion channel that is inserted and arranged in the insertion section 1 is disposed in the vicinity of a connection portion between the insertion section 1 and the operation section 2. Reference numeral 6 denotes an optical system operation lever for performing a focusing or zooming operation.
[0012]
A connector 8 is connected to the distal end of the flexible connecting tube 7 connected to the rear portion of the operation unit 2, and this connector 8 supplies illumination light to an illumination light guide fiber bundle, which will be described later, and the distal end body 10. Are connected to a light source device / video processor (not shown) for processing a video signal picked up by a built-in solid-state image pickup device.
[0013]
FIG. 3 is a front view of the distal end body 10, 11 is an observation window for taking an observation image, 12 is an illumination window for emitting illumination light for illuminating the subject, and 13 is an exit of the treatment instrument insertion channel. , 14 and 15 are an air supply nozzle and a water supply nozzle.
[0014]
4 is a side cross-sectional view of the distal end portion of the insertion portion 1 in a cross section passing through each center line of the observation window 11 and the illumination window 12, FIG. 5 is a VV cross-sectional view thereof, and 4 and 10 are the above-mentioned It is a bending part and a front-end | tip part main body.
[0015]
The illumination window 12 is fitted with a concave lens 17 that widens the light distribution angle of illumination light, and an exit end of the light guide fiber bundle 18 is disposed inside the concave lens 17. Further, a cover lens 20 that is a first lens of the objective optical system is fitted in the observation window 11, and an objective lens group 21, a solid-state imaging device 24, and the like are disposed on the inside thereof. 22 is a YAG laser cut filter and 23 is a cover glass.
[0016]
The framework of the curved portion 4 is configured by connecting a plurality of node rings rotatably with rivets, and the most advanced node ring 4a is fitted on the outer peripheral surface of the rear end portion of the tip body 10. It is connected and fixed by a fixing screw 4b.
[0017]
Reference numeral 4c denotes a screw piece disposed in a recess formed in the distal end body 10 for screwing the fixing screw 4b, 4d denotes a bending operation wire, and 4e denotes a stretchable rubber exterior tube.
[0018]
FIG. 1 shows an enlarged configuration around the objective optical systems 20 and 21 and the solid-state imaging device 24 in a normal observation state, and FIGS. 6 and 8 show a VI-VI section and a VIII-VIII section.
[0019]
A fixed inner cylinder 28 (fixed cylinder) is directly fitted on the rear side as shown in FIG. 6 with respect to a fixed outer cylinder 27 fitted and fixed in a hole formed in the axial direction of the tip body 10. The space ring 30 is inserted and fixed between the two 27 and 28 on the front side, and a constant gap is secured between the two 27 and 28 over the entire length excluding both ends. Yes.
[0020]
The cover lens 20 is watertightly 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 body 10.
[0021]
A gap between the front lid 31 and the side surface of the cover lens 20 is filled with a defoamed epoxy adhesive, and a sealing O-ring 32 is provided on the fitting surface between the front lid 31 and the tip body 10. Is installed.
[0022]
In the fixed inner cylinder 28, an objective frame 34 to which the objective lens group 21 is attached and an image receiving part frame 35 to which a solid-state imaging device 24 for taking an observation image is attached are independent of each other in the axial direction. It is inserted so that it can move forward and backward. 33 is an O-ring.
[0023]
The objective lens group 21 is assembled in a lens cylinder 36 and fixed by caulking, and the lens cylinder 36 is joined to the objective frame 34. However, the lens tube 36 may be screwed to the objective frame 34.
[0024]
Reference numeral 37 denotes a light shielding mask for cutting unnecessary ambient light. The aperture stop is disposed on the front end face of the objective lens group 21. Between the objective frame 34 and the image receiving portion frame 35, a first compression coil spring 47 that urges both the plates 34 and 35 in a direction away from each other is interposed to prevent rattling.
[0025]
The solid-state image sensor 24 is fixed to the tip of a flexible substrate 44 such as a TAB (tape automated bonding) substrate, for example, and a cover glass 23 is bonded to the front end surface of the solid-state image sensor 24, and a YAG laser cut filter 22 is joined to the front end face of the cover glass 23.
[0026]
In the flexible substrate 44, a buffer substrate 43 on which electronic components constituting a drive circuit of the solid-state imaging device 24 and the like are mounted is disposed, and a signal cable 45 is drawn behind the buffer substrate 43.
[0027]
On the outer peripheral surfaces of the cover glass 23, the solid-state imaging device 24, and the flexible substrate 44, a thin electrically insulating insulating tape 38 is continuously wound, and a shield cylinder 40 made of a conductive cylindrical body is provided. It is fitted on the outside. A shield wire of a signal cable 45 is connected to the shield tube 40.
[0028]
Since the tip of the shield tube 40 is located in the middle of the side surface of the solid-state imaging device 24, the electrically insulating epoxy adhesive 41 defoamed from the outer surface portion of the insulating tape 38 from there to the tip of the cover glass 23. Is filled.
[0029]
The insulating tape 39 is continuously wound from that portion to the outer periphery of the shield tube 40 to ensure electrical insulation between the shield tube 40 and the image receiving frame 35. Reference numeral 46 denotes a silicon-based adhesive filled on the rear end side in order to prevent dust from entering the image receiving unit frame 35.
[0030]
The shield cylinder 40 in which the solid-state imaging device 24 and the electronic circuit are accommodated in this way is pressed and fixed by a fixing screw 42 screwed into the image receiving unit frame 35. The fixing screw 42 is once loosened when performing the focus adjustment in the normal observation state, and further switched to the close-up magnification observation state to be described later to check the focus. Fix to 35.
[0031]
However, since the insulating tape 39 is interposed between the front end surface of the fixing screw 42 and the outer peripheral surface of the shield tube 40, electrical insulation between the image receiving portion frame 35 and the shield tube 40 is ensured. Yes.
[0032]
A cylindrical cam cylinder 50 in which first, second and third cam grooves 51, 52, 53 are formed is fitted on the outer peripheral surface of the fixed inner cylinder 28 so as to be rotatable about an axis. A slide cylinder 55 that is driven by the operation wire 25 and slides in the axial direction is disposed at a position surrounding the cam cylinder 50.
[0033]
The distal end of the operation wire 25 is passed through a hole formed in the slide cylinder 55, and a retaining ring 57 is fixed to the distal end. The slide cylinder 55 is slid rightward in FIG. 1 by operating the optical system operation lever 6 and pulling the operation wire 25 from the operation unit 2 side.
[0034]
When the operation wire 25 is moved in the reverse direction (ie, forward), the slide cylinder 55 is moved to the left in FIG. 1 by the urging force of the second compression coil spring 58 disposed around the outer periphery of the fixed inner cylinder 28. Slide driven. The urging force of the second compression coil spring 58 is set to be stronger than the urging force of the first compression coil spring 47 in the normal observation state.
[0035]
Reference numerals 62 and 63 are double-structured guide tubes for guiding the operation wire 25 in the insertion portion 1, and are composed of a flexible tube 62 on the inside and a tightly wound coil pipe 63 having a rectangular cross section on the outside. It is bonded and fixed to a connection pipe 61 soldered to the cylinder 27. The flexible tube 62 has a function of preventing the lubricant applied to various built-in objects in the insertion portion 1 from entering.
[0036]
A first pin 65 that is movably engaged with the first cam groove 51 formed in the cam cylinder 50 without a back end is screwed and fixed to the slide cylinder 55 so as to protrude inward. Yes.
[0037]
The objective frame 34 is screwed and fixed so that a second pin 66 whose head engages with the second cam groove 52 protrudes outward, and the image receiving section frame 35 has a third pin. A third pin 67 whose head engages with the cam groove 53 is screwed and fixed so as to protrude outward.
[0038]
In the fixed inner cylinder 28, rectilinear grooves 68 and 69 through which the second pin 66 and the third pin 67 pass are formed in a direction parallel to the axis. Further, since the heads of the second pin 66 and the third pin 67 engage with the second cam groove 52 and the third cam groove 53, as shown in FIG. Slot grooves 66a and 67a with which the tip is engaged are formed by a half-moon-shaped depression that is not exposed on the side surface (outer peripheral surface).
[0039]
As a result, regardless of the directionality in which the pins 66 and 67 are screwed and fixed, since the slit grooves 66a and 67a do not contact the cam grooves 52 and 53, smooth operation without roughness can be obtained. Further, since it is not necessary to increase the height of the pins 66 and 67, the mechanism does not increase in size, and an insertability that allows the tip body 10 to be formed thin can be obtained.
[0040]
FIG. 7 is a developed view showing an engagement state between the first to third cam grooves 51, 52, 53 and the first to third pins 65, 66, 67. The pins 65, 66, 67 are respectively shown in FIG. It is in the position of the normal observation state shown in FIG. 1 and FIG.
[0041]
The angle θ formed by the first cam groove 51 with the axial direction (that is, the optical axis direction) of the cam cylinder 50 is in the range of 10 ° to 45 ° in order to perform a smooth operation with a small amount of operating force. Is desirable. In this embodiment, θ≈30 ° is set.
[0042]
When the operation wire 25 is pulled by operating the optical system operation lever 6 of the operation unit 2 from this normal observation state, the slide cylinder 55 moves backward against the urging force of the second coil spring 58 as shown in FIG. The cam cylinder 50 is rotationally driven around the axis by the engagement of the first pin 65 and the first cam groove 51 that slides (moves to the right in FIG. 10) and moves with the first pin 65. The rotation angle is 90 ° at the maximum.
[0043]
When the cam cylinder 50 rotates around 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 cylinder 50 are moved in the axial direction. The objective frame 34 slides forward (leftward in FIG. 10) and the image receiving part frame 35 slides backward (rightward in FIG. 10).
[0044]
The length of the first cam groove 51 is exactly 90 ° in terms of the rotation angle of the cam barrel 50, but the second and third cam grooves 52 and 53 are obtained when the cam barrel 50 is rotated by 90 °. Both end portions are formed longer than the first cam groove 51. As a result, the first cam groove 51 and the first pin 65 that engages with the first cam groove 51 serve as a stopper that restricts the rotation angle of the cam barrel 50.
[0045]
FIG. 11 is an exploded view showing an engagement state between the first to third cam grooves 51, 52, 53 and the first to third pins 65, 66, 67 in a state in which the cam cylinder 50 is rotated by 90 °. Yes, FIG. 12 shows a cross section XII-XII.
[0046]
In the state shown in FIGS. 10 to 12, the cover lens 20 does not move, the objective lens group 21 moves forward, and the solid-state imaging device 24 moves backward.
[0047]
As a result, zooming is performed. For example, in normal observation, the viewing angle is 120 ° and the observation distance is in the range of 5 to 100 mm, but the viewing angle is 40 ° and the observation distance is in the range of 2 to 4 mm. It becomes a microscopic close-up observation state.
[0048]
If the optical system operation lever 6 is stopped at an arbitrary position in the middle, the objective frame 34 and the image receiving unit frame 35 driven via the operation wire 25 and the slide cylinder 55 stop at the intermediate position in the movement range, Observation can be performed at an arbitrary magnification between the observation state and the close-up magnification observation state.
[0049]
The present invention is not limited to the above embodiment. For example, the slits 66a and 67a of the second and third pins 66 and 67 are not limited to a half-moon shape. For example, as shown in FIG. May be flat.
[0050]
Further, only the focusing may be operated by the cam mechanism of the present invention, and both focusing and zooming may be performed. Further, the movement of the operation wire 25 may be performed by either the objective lens group 21 or the solid-state imaging device 24. Further, the mechanism in the endoscope other than the objective optical system may be operated by the cam mechanism of the present invention.
[0051]
【The invention's effect】
According to the present invention, since the slit groove is formed on the head of the pin that is screwed and fixed to the movable member and engages with the cam groove without exposing the outer peripheral surface, the direction when the pin is screwed and fixed Regardless of the nature, the slit groove does not come into contact with the cam groove, so it is possible to obtain smooth operation without roughness and the like, and it is not necessary to increase the height of the pin. Can be incorporated into the tip of the insertion part without any problem.
[Brief description of the drawings]
FIG. 1 is an enlarged side sectional view of an objective optical system portion in a normal observation state according to an 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 distal end of the insertion portion of the endoscope according to the embodiment of the present invention.
FIG. 4 is a side sectional view of the distal end of the insertion portion of the endoscope according to the embodiment of the present invention.
5 is a cross-sectional view taken along line VV in FIG. 4 according to the embodiment of the present invention.
6 is a cross-sectional view taken along the line VI-VI in FIG. 1 according to the embodiment of the present invention.
FIG. 7 is a development view showing an engaged state between the cam groove and the pin in the normal observation state according to the embodiment of the present invention.
8 is a cross-sectional view taken along the line VIII-VIII in FIG. 1 according to the embodiment of the present invention.
FIG. 9 is a perspective view of a pin according to the embodiment of the present invention.
FIG. 10 is an enlarged side cross-sectional view of an objective optical system portion in a close-up magnification observation state according to an embodiment of the present invention.
FIG. 11 is a development view showing an engagement state between the cam groove and the pin in the close-up magnification observation state according to the embodiment of the present invention.
12 is a cross-sectional view taken along the line XII-XII in FIG. 10 according to the embodiment of the present invention.
FIG. 13 is a side view showing a part of the pin of the second embodiment of the present invention in cross section.
FIG. 14 is a perspective view of a pin used in a conventional endoscope cam mechanism.
FIG. 15 is a front view of another pin used in a cam mechanism of a conventional endoscope.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Insertion part 6 Optical system operation lever 21 Objective lens group 24 Solid-state image sensor 25 Operation wire 34 Objective frame 35 Image receiving part frame 50 Cam cylinder 55 Slide cylinder 66, 67 Pin 66a, 67a Slot groove

Claims (5)

In an endoscope cam mechanism in which a rotary motion is converted into a linear motion or a linear motion is converted into a rotational motion by engaging a head of a pin screwed and fixed to a movable member with a cam groove.
The cam groove is formed in a cam cylinder disposed in the distal end of the insertion portion so as to be rotatable about an axis, and the cam cylinder is rotationally driven via an operation wire that moves in the axial direction by remote operation. An endoscope cam mechanism, wherein the movable member is driven in an axial direction via the pin engaged with a cam groove . 2. The inner groove according to claim 1 , wherein a slot groove for engaging a tip of a tool when the pin is screwed into the movable member is formed in a head portion of the pin without being exposed to an outer peripheral surface of the pin . Endoscope cam mechanism. The endoscope cam mechanism according to claim 2 , wherein the slit groove is formed by a half-moon-shaped depression. 4. The endoscope cam mechanism according to claim 1, wherein the movable member is one or both of an objective frame to which an objective optical system is attached and an image receiving portion frame to which an image receiving portion of an image transmission means is attached. The endoscope cam mechanism according to claim 4, wherein at least one of or both of focusing and zooming is performed by movement of at least one of the objective frame and the image receiving unit frame.

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