JP4426054B2 - Endoscope objective drive mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an endoscope objective drive mechanism having a function such as focusing or zooming.
[0002]
[Prior art]
In order to perform focusing or zooming in an endoscope, it is necessary to move the objective optical system part built in the distal end of the insertion part in the axial direction by remote control. However, the insertion part of the endoscope is long and narrow. Therefore, such remote operation must be performed via an operation wire.
[0003]
However, if the tip of the operation wire is directly connected to the objective frame and the operation wire is advanced or retracted, the tensile force of the operation wire acts directly on the objective frame, so the objective frame is tilted by the backlash with the fixed inner cylinder, and the observation image However, there is a problem that the image is partially out of focus.
[0004]
Accordingly, the applicant of the present invention has a configuration in which the objective frame is not tilted by advancing and retracting the operation wire in the axial direction, and the distal end of the operation wire is placed in a slide cylinder slidably disposed in the axial direction within the distal end of the insertion portion. And at least one of the objective frame to which the objective optical system is attached and the image receiving portion frame to which the image receiving portion of the image transmitting means is attached is axially disposed in a fixed inner cylinder fixedly disposed in the distal end of the insertion portion. The cam cylinder, which is slidably inserted into the shaft and is fitted to the fixed inner cylinder so as to be rotatable about the axis, is rotated around the axis by the sliding movement of the slide cylinder, so that at least the objective frame and the image receiving unit frame An invention in which one of them is driven in the axial direction has been filed earlier (Japanese Patent Laid-Open No. 7-202677).
[0005]
[Problems to be solved by the invention]
In the endoscope objective drive mechanism as described above, the fixed outer cylinder for restricting the axial movement of the cam cylinder is fixed to the fixed inner cylinder so as to surround the slide cylinder and the cam cylinder. In the conventional endoscope objective drive mechanism described in Japanese Patent Laid-Open No. 7-202777, the rear end portions of both cylinders are provided by a small screw in which a fixed inner cylinder and a fixed outer cylinder are arranged in a radial direction. The connection was fixed with.
[0006]
However, both the fixed inner cylinder and the fixed outer cylinder are elongated, and there is a large gap between the cylinders in which the slide cylinder and the cam cylinder are arranged. When the rear end portions of the cylinders are connected and fixed, distortion and axial displacement are likely to occur between the cylinders, which may cause problems such as poor focus due to the cam cylinder rattling in the axial direction.
[0007]
Therefore, the present invention provides an objective drive for an endoscope capable of stably connecting and fixing a fixed inner cylinder and a fixed outer cylinder, which are arranged between a slide cylinder and a cam cylinder, so that the cam cylinder does not rattle. The purpose is to provide a mechanism.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the endoscope objective drive mechanism of the present invention is arranged such that the distal end of an operation wire that moves in the axial direction by remote operation is connected and slidable in the axial direction within the distal end of the insertion portion. At least one of the slide cylinder, the objective frame to which the objective optical system is attached, and the image receiving portion frame to which the image receiving portion of the image transmitting means is attached is slidably inserted in the axial direction so as to be fixed in the distal end of the insertion portion. Fixed between the objective frame and the image receiving unit frame by being fixedly fitted to the fixed inner cylinder arranged on the fixed inner cylinder and rotated around the axis by the sliding movement of the slide cylinder. A cam cylinder that drives the frame that is slidably inserted into the inner cylinder in the axial direction, and a fixed inner cylinder that is disposed so as to surround the slide cylinder and the cam cylinder and restricts the axial movement of the cam cylinder. Fixed fixed In the objective drive mechanism of the endoscope provided with the cylinder, the fixed inner cylinder and the fixed outer cylinder are fitted at least at both ends, and a male screw is formed around the axis at one end of the fixed inner cylinder, The fixed outer cylinder is pressed and fixed in the axial direction to the fixed inner cylinder by a pressing nut screwed to the male screw.
[0009]
In addition, the external thread may be formed in the front-end | tip part of a fixed inner cylinder, and the fixed outer cylinder and the fixed inner cylinder may be press-fixed by the press nut in the front-end | tip part of both cylinders.
[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 operation of the objective optical system.
[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. Is connected to a light source device / video processor (not shown) for processing a video signal picked up by a solid-state image pickup element incorporated in the image pickup device.
[0013]
FIG. 3 is a side sectional view of the tip body 10, and FIG. 1 is a side sectional view of an objective drive mechanism incorporated therein, and the tip body 10 is made of a stainless steel body as shown in FIG. 3. The cover portion 10b made of an electrically insulating plastic is covered and joined to the portion 10a.
[0014]
Reference numeral 4 denotes the above-described curved portion, 11 denotes an observation window for taking an observation image, 12 denotes an illumination window for emitting illumination light for illuminating the subject, and 14 denotes an air / water supply nozzle.
[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 a light guide fiber bundle 18 that transmits the illumination light is disposed inside the illumination lens 12.
[0016]
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 inside the cover lens 20. 22 is a YAG laser cut filter and 23 is a cover glass.
[0017]
The fixed inner cylinder 28 is pressed against a fixed outer cylinder 27 that is fitted and fixed in a hole formed in the axial direction of the distal end main body 10 and is screwed into a male screw portion formed around the axial line at the front end thereof. The nut 30 is pressed in the axial direction and integrally connected and fixed.
[0018]
The fixed outer cylinder 27 and the fixed inner cylinder 28 are fitted with no back and forth at both ends, and a fixed gap is secured between the two 27 and 28 at portions other than the front and rear ends.
[0019]
As shown in FIG. 1, a wall-like portion 27a that forms a plane perpendicular to the axis is formed in the front end portion of the fixed outer cylinder 27 that is formed in a constant cross-sectional shape as shown in FIG. ing.
[0020]
The wall-shaped portion 27a is fitted to the outer peripheral surface of the fixed inner cylinder 28, and is pressed against the step wall 28a formed in the fixed inner cylinder 28 in the axial direction by the pressing nut 30, thereby fixing the fixed outer cylinder. 27 and the fixed inner cylinder 28 are integrally connected and fixed without any displacement. Reference numeral 31 denotes an electrically insulating cover attached so as to surround the pressing nut 30.
[0021]
An objective frame 36 to which the objective lens group 21 is attached is fitted and fixed inside the front side portion of the fixed inner cylinder 28, and the fixed inner cylinder 28 is used to capture an observation image. An image receiving part frame 35 to which the solid-state imaging device 24 is attached is inserted so as to be movable back and forth in the axial direction.
[0022]
Between the objective frame 36 and the image receiving portion frame 35, a first compression coil spring 47 that urges both the plates 36 and 35 in a direction away from each other is interposed to prevent rattling. 33 is an O-ring.
[0023]
The solid-state image sensor 24 is fixed to the front end 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 so that a YAG laser cut filter is used. 22 is joined to the front end face of the cover glass 23.
[0024]
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.
[0025]
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.
[0026]
A shield wire of a signal cable 45 is connected to the shield tube 40, and an insulating tape 39 is continuously wound around the outer periphery of the shield tube 40, so that electrical insulation between the shield tube 40 and the image receiving unit frame 35 is provided. It is secured.
[0027]
In this way, the shield cylinder 40 in which the solid-state imaging device 24 and the electronic circuit are accommodated is pressed and fixed by the fixing screw 42 screwed into the image receiving unit frame 35. 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.
[0028]
A cylindrical cam cylinder 50 in which first and second cam grooves 51 and 53 are formed on the outer peripheral surface of the front portion of the fixed inner cylinder 28 rotates around the axis so as not to move in the axial direction. Freely fitted.
[0029]
A front end wall 50a that is slightly inward from the outer edge is formed at the front end portion of the cam cylinder 50 that is formed in a cylindrical cross-sectional shape as a whole. The front end wall 50a is formed on the fixed inner cylinder 28. The cam cylinder 50 is restricted from moving in the axial direction by being sandwiched between the stepped wall 28a and the wall-shaped portion 27a of the fixed outer cylinder 27 without rattling.
[0030]
A slide cylinder 55 that is driven by the operation wire 25 and slides in the axial direction is fitted on the outer peripheral surface of the intermediate portion of the fixed inner cylinder 28 so as to be movable in the axial direction. Therefore, the cam cylinder 50 and the slide cylinder 55 are formed to have the same inner diameter.
[0031]
The distal end of the operation wire 25 is passed through a hole drilled in the rear end of the slide cylinder 55, and a retaining ring 57 is fixed to the distal end of the operation wire 25. 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.
[0032]
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.
[0033]
Reference numerals 62 and 63 are double-structured guide tubes for guiding the operation wire 25 in the insertion portion 1. The inner tube comprises a tightly wound coil pipe 62 and the outer side is a flexible tube 63, and is soldered to the fixed outer cylinder 27. It is fixed to the fixed connection pipe 61 by adhesion. The flexible tube 63 has a function of preventing the lubricant applied to various built-in objects in the insertion portion 1 from entering.
[0034]
A pin mounting protrusion 55a is formed on the slide cylinder 55 so as to protrude forward. As shown in FIG. 4 illustrating the IV-IV cross section, the pin mounting protrusion 55a is formed to have a minimum width necessary for screwing and fixing the first pin 65.
[0035]
And only the part which accommodates the pin attachment protrusion 55a of the fixed outer cylinder 27 formed in circular cross-sectional shape protrudes in a convex shape, and the fixed outer cylinder 27 is formed in the cross-sectional shape over the entire length, and the protrusion An operation wire 25 or the like is arranged in accordance with the portion.
[0036]
As shown in FIGS. 1 and 4, the pin mounting protrusion 55a of the slide cylinder 55 is disposed so that the inner surface thereof is loosely in contact with the outer periphery of the cam cylinder 50, and is fixed to the pin mounting protrusion 55a. The tip of the pin 65 protrudes inward, and engages with the first cam groove 51 formed in the cam cylinder 50 so that it can move freely.
[0037]
A second pin 67 whose head engages with a second cam groove 53 formed in the cam barrel 50 is screwed and fixed to the objective frame 36 so as to protrude outward. In the fixed inner cylinder 28, a rectilinear groove 69 through which the second pin 67 passes is formed in a direction parallel to the axis.
[0038]
FIG. 5 is a developed view showing an engagement state between the first and second cam grooves 51 and 53 and the first and second pins 65 and 67. The pins 65 and 67 are in the state shown in FIG. In the position.
[0039]
When the operation wire 25 is pulled by operating the optical system operation lever 6 of the operation unit 2 from this state, the slide cylinder 55 slides backward (to the right in FIG. 1) against the urging force of the second compression coil spring 58. Then, the cam cylinder 50 is rotationally driven around the axis by the engagement between the first pin 65 and the first cam groove 51 that move together with the first pin 65. The rotation angle is, for example, 40 ° at the maximum.
[0040]
When the cam cylinder 50 rotates around the axis, the second pin 67 engaged with the second cam groove 53 formed in the cam cylinder 50 is moved in the axial direction, and the image receiving frame 35 is moved backward (in FIG. 1). Slide to the right), the subject distance in focus will be shortened, and focusing will be performed.
[0041]
The present invention is not limited to the above-described embodiments. For example, zooming or both may be performed instead of focusing, and the objective lens group 21 and the solid-state imaging device are moved by pulling the operation wire 25. Either one or both of 24 may be used.
[0042]
【The invention's effect】
According to the present invention, since the fixed outer cylinder is pressed and fixed to the fixed inner cylinder in the axial direction by the pressing nut screwed with the male screw formed around the axis of the fixed inner cylinder, the cam cylinder does not rattle. The fixed inner cylinder and the fixed outer cylinder can be connected and fixed in a stable state, and as a result, a clear endoscopic observation image with no focus failure can be obtained.
[Brief description of the drawings]
FIG. 1 is a side sectional view of an endoscope objective drive mechanism according to an embodiment of the present invention.
FIG. 2 is a side view showing an overall configuration of an endoscope according to an embodiment of the present invention.
FIG. 3 is a side sectional view of the distal end of the insertion portion of the endoscope according to the embodiment of the present invention.
4 is a cross-sectional view taken along the line IV-IV in FIG. 1 according to the embodiment of the present invention.
FIG. 5 is a development view showing an engagement state between a cam groove and a pin of an objective drive mechanism of an endoscope according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Tip part main body 21 Objective lens group 24 Solid imaging device 25 Operation wire 27 Fixed outer cylinder 28 Fixed inner cylinder 30 Pressing nut 35 Image receiving part frame 36 Objective frame 50 Cam cylinder 55 Slide cylinder

Claims (1)

The distal end of an operation wire that moves in the axial direction by remote operation is connected, the slide cylinder is slidably disposed in the distal end of the insertion portion in the axial direction, the objective frame to which the objective optical system is attached, and the image receiving means A fixed inner cylinder in which at least one of the image receiving part frames to which the part is attached is slidably inserted in the axial direction and is fixedly disposed in the distal end of the insertion part, and the fixed inner cylinder is rotatable around the axis The frame inserted and slidably inserted into the fixed inner cylinder among the objective frame and the image receiving section frame is rotated by the sliding movement of the slide cylinder and rotated about the axis. A cam cylinder that is driven in a direction, and a fixed outer cylinder that is disposed so as to surround the slide cylinder and the cam cylinder and that is connected and fixed to the fixed inner cylinder so as to restrict axial movement of the cam cylinder. The The objective drive mechanism of the viewing mirror,
Said fixed inner tube and the fixed outer cylinder is fitted at least at both ends, a male screw about its axis in the forward end portion of the fixed inner tube is formed, at the front end portion of the inner and outer tubular, said fixed outer cylinder Is pressed and fixed to the fixed inner cylinder from the front to the rear with a press nut screwed to the male screw ,
A front end wall directed inward from an outer edge is formed at the front end of the cam cylinder, and the front end wall engages with a step formed on an outer peripheral portion in the vicinity of the front end of the fixed inner cylinder to fix the fixed position. Objective driving of an endoscope characterized in that the cam cylinder is sandwiched in an axial direction in a state where it is not rattled but not fixed between the inner cylinder and the fixed outer cylinder, thereby restricting movement of the cam cylinder in the axial direction. mechanism.

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