JP2005192774A - Zoom endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a zoom endoscope which is precisely and easily focused in the case of short range and magnifying observation by easily keeping an optimal distance from the mucosa face of a subject in the case of short range and magnifying observation without using a distal end hood etc., so as to form the distal end diameter of an insertion part to be thin. <P>SOLUTION: A distal end main body 10 is connected to the distal end part of the insertion part 1 in the state of being movable forward and backward by a distance L equal to or longer than the maximum moving distance S of the focusing position of objective optical systems 20 and 21, and a distal end main body advance/retreat operation device 7 for performing advance/retreat operation to the distal end main body 10 forward and backward is arranged at an operation part 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a zoom endoscope having an objective optical system with a variable focal length so that close-up magnification observation can be performed.

  In order to perform microscopic close-up magnification observation of the mucosal surface with an endoscope, it is necessary to increase the focal length of the objective optical system, but for a guidance operation of the endoscope, a wide-angle visual field with a short focal length is required. Therefore, a zoom endoscope is used.

  Such a zoom endoscope generally operates an objective optical system with a variable focal length built in the distal end of an insertion portion by an operation wire that is moved back and forth in the axial direction by a remote operation from a hand side operation portion. .

  However, if the focal length of the objective optical system is increased in order to perform close-up magnification observation, the depth of focus becomes shallow, and the subject will be out of focus just by moving slightly away from the best focus distance. When performing, it is necessary to keep an appropriate distance from the subject mucosal surface.

Therefore, conventionally, a tip hood, a protruding pin, etc. (hereinafter referred to as “tip hood”) that can be pressed against the subject mucosal surface to maintain a constant distance from the subject mucosal surface can be moved forward and backward in the axial direction at the tip of the insertion portion The tip hood and the like are moved back and forth in conjunction with the change of the focal length of the objective optical system (for example, Patent Documents 1 and 2).
JP 11-342104 A JP2000-207178A

  However, if the tip hood is attached, the distal end of the insertion section becomes thicker. Therefore, in the case of an endoscope for colon examination that is inserted into the body from the anus, even if there are few problems, The pain given to the subject increases with an endoscope or the like.

  In addition, since the tip hood is used while being pressed against the mucosal surface of the subject, the mucosal surface is compressed, and the tip hood and the like are directly subjected to the movement of the mucosal surface. It was difficult, and it was difficult to focus accurately during close-up magnification observation.

  Therefore, the present invention can easily maintain the optimum distance from the subject mucosa surface during close-up magnification observation without using a tip hood so that the distal end outer diameter of the insertion portion can be formed thin, and close-up observation An object of the present invention is to provide a zoom endoscope that can easily perform accurate focusing sometimes.

  In order to achieve the above object, the zoom endoscope of the present invention focuses on the distal end body connected to the distal end of the insertion section so that the close-up observation of the observation range in front of the distal end body can be performed. An objective optical system in which the distance is variable and the in-focus position moves as the focal length changes is arranged, and an operation for changing the focal length of the objective optical system is performed on the operation unit connected to the proximal end side of the insertion unit. In a zoom endoscope in which a zoom operation device for performing is arranged, the distal end portion of the insertion portion is movable in the front-rear direction by a distance equal to or longer than the maximum moving distance of the focusing position of the objective optical system. And a tip part main body advancing / retracting device for moving the tip part main body back and forth in the front-rear direction.

  The objective optical system is configured such that a zoom operation wire that is moved back and forth in the axial direction by the zoom operation device to change the focal length of the objective optical system is inserted and arranged in the insertion portion, and the zoom operation wire is pulled from the operation portion side. At the same time, the close-up observation state in which the in-focus position approaches the tip end body may be made.

  Further, a distal end main body advancing / retracting operation wire that is advanced / retreated in the axial direction by the distal end main body advancing / retreating device is inserted and arranged in the insertion portion, and the distal end main body is moved forward in the distal end portion of the insertion portion. An urging means for urging may be provided, and when the distal end portion main body advance / retreat operation wire is pushed out from the operation portion side, the distal end portion main body may move forward by the urging force of the urging means.

  According to the present invention, the distance to the subject mucosal surface can be easily maintained in an optimal state during close-up magnification observation without using a tip hood or the like, and accurate focusing can be easily performed during close-up magnification observation. In addition, since a tip hood or the like is unnecessary, the outer diameter of the tip of the insertion portion can be formed thin, and the pain of the subject in an upper digestive tract examination can be reduced.

  To connect the tip body to the tip of the insertion part so that it is movable in the front-rear direction by a distance equal to or longer than the maximum movement distance of the in-focus position of the objective optical system, and to move the tip body forward and backward The tip body main body advancing / retreating device is arranged in the operating portion.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 4 shows the overall configuration of the zoom endoscope. The operation portion 2 is connected to the proximal end of the flexible tubular insertion portion 1, and the bending portion 4 formed near the distal end of the insertion portion 1 includes an operation portion. By rotating the bending operation knob 3 provided at 2, it can be bent in an arbitrary direction by an arbitrary angle.

  Objective optical systems 20 and 21 are incorporated in the distal end body 10 connected to the front side of the bending section 4 so as to be positioned at the forefront of the insertion section 1, and the projection position of the subject by the objective optical systems 20 and 21 is included. The solid-state imaging device 24 is disposed on the surface.

  The objective optical systems 20 and 21 are so-called zoom optical systems with variable focal lengths, and a zoom operation wire 25 for transmitting an operation for changing the focal lengths of the objective optical systems 20 and 21 is provided from the insertion unit 1 to the operation unit. The zoom operation wire 25 is advanced and retracted by a manual zoom operation lever 6 (zoom operation device) disposed in the operation unit 2.

  Further, the distal end body 10 is disposed so as to be able to advance and retract in the front-rear direction with respect to the distal end of the bending portion 4, and the distal end body advancing / retracting operation wire 81 for advancing and retracting the distal end body 10 is a zoom operation wire 25. Independently from the insertion portion 1, the distal end main body is advanced and retracted by a manual distal end main body advancing / retracting lever 7 (tip main body advancing / retracting operation device) disposed in the operating portion 2. The operation wire 81 is moved forward and backward.

  FIG. 2 shows a distal end portion of the insertion portion 1 in a normal observation state where a wide-angle visual field can be obtained. For example, an observation window 11 is disposed on the distal end surface of the distal end main body 10 made of ceramic or the like, and a cover lens 20 as a first lens of the objective optical system is fitted and fixed therein. An illumination window (not shown) is arranged side by side with the observation window 11.

  An objective lens group 21, a solid-state image sensor 24, and the like are disposed inside the cover lens 20, and a subject image in front of the front end body 10 (downward in FIG. 2) is projected onto the imaging surface of the solid-state image sensor 24. Is done.

  The fixed inner cylinder 28 is directly fitted at the rear end portion and fixed with the fixing screw 29 with respect to the fixed outer cylinder 27 fitted and fixed in the hole formed in the axial direction on the distal end body 10. A space ring 30 is inserted and fixed between both the cylinders 27 and 28, and a constant gap is secured between the fixed outer cylinder 27 and the fixed inner cylinder 28 over the entire length except for both ends.

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

  In the fixed inner cylinder 28, an objective frame 34 to which a lens cylinder 36 incorporating 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 mutually connected. It is inserted and inserted independently in the axial direction. A first compression coil spring 47 is interposed between the frames 34 and 35 to prevent rattling.

  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, and the YAG cut filter 22. Is joined to the front end face of the cover glass 23.

  In the flexible substrate 44, a buffer substrate on which several electronic components constituting a drive circuit for the solid-state imaging device 24 and the like are mounted is disposed, and a signal cable 45 is drawn behind the buffer substrate.

  A cylindrical cam cylinder 50 formed with first, second and third cam grooves 51, 52, 53 is fitted on the outer peripheral surface of the fixed inner cylinder 28 so as to be rotatable around an axis line. A slide cylinder 55 that is driven by the zoom operation wire 25 and slides in the axial direction is disposed at a position surrounding the cam cylinder 50.

  The distal end of the zoom operation wire 25 is passed through a hole formed in the slide cylinder 55, and a retaining ring 57 is fixed to the front side portion thereof. The slide cylinder 55 is slid rearward (upward in FIG. 2) by operating the zoom operation lever 6 and pulling the zoom operation wire 25 from the operation unit 2 side.

  When the zoom operation wire 25 is moved in the reverse direction (ie, forward), the slide cylinder 55 is slid forward by the urging force of the second compression coil spring 58 disposed around the outer periphery of the fixed inner cylinder 28. Is done. 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.

  A first pin 65 that engages the first cam groove 51 formed in the cam cylinder 50 without rattling is fixed to the slide cylinder 55 by being screwed and fixed so as to protrude inward. Yes.

  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. 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, the portion near the rear end of the distal end main body 10 of this embodiment is loosely fitted into the most advanced node ring 4a constituting the curved portion 4 so as to be slidable in the axial direction. A movement range restricting pin 83 projecting from the side surface of the front end engages with a straight groove 82 formed in the most advanced node ring 4a in a direction parallel to the axis.

  Therefore, the distal end portion body 10 is movable in the axial direction at the distal end of the insertion portion 1 within a range L in which the movement range restricting pin 83 is movable with respect to the linear groove 82, and the rotational movement around the axis is the movement range restricting pin 83. And the linear groove 82 are prevented from engaging with each other.

  The tip end portion of the tip portion main body advance / retreat operation wire 81 is connected and fixed to the rear end portion of the tip portion main body 10, and the tip portion body urging compression coil spring 84 ( Urging means) is attached, and the tip body 10 is constantly urged forward with respect to the most advanced node ring 4a. And the outer surface of the part is continuously coat | covered with the elastic rubber tube 5 which coat | covers the curved part 4. FIG.

  Therefore, as shown in FIG. 2, in the state where the distal end main body advancing / retreating operation wire 81 is pulled from the operation section 2 side, the distal end main body 10 compresses the distal end main body urging compression coil spring 84 and moves within the moving range. When the distal end main body advancing / retracting operation wire 81 is pushed forward from the operation section 2 side, the distal end main body 10 is moved forward (downward in FIG. 2) by the urging force of the distal end main body urging compression coil spring 84. )

  With such a configuration, in the normal observation state shown in FIG. 2, the distal end main body advancing / retracting operation wire 81 is pulled toward the operation section 2, and the distal end main body 10 is moved to the rear end position (movement range restriction). The pin 83 is at the A position), and the focal length of the objective lens group 21 including the cover lens 20 is minimized, and a viewing angle of, for example, about 120 ° is obtained.

  Since the focal length is short, a very deep depth of focus can be obtained, and a clear observation image can be obtained from the surface of the observation window 11 within a range of, for example, 5 to 100 mm without performing focus adjustment. The in-focus position (the farthest in-focus position) is, for example, about 10 mm from the surface of the observation window 11.

  From such a normal observation state, when the zoom operation lever 6 is operated in the operation unit 2 and the zoom operation wire 25 is pulled to the operation unit 2 side, the slide cylinder 55 is moved to the second compression coil spring 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 which slides backward against the urging force 58 and moves together therewith.

  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 and the image receiving unit frame 35 slides backward.

  As a result, the objective lens group 21 including the cover lens 20 is in a close-up magnification observation state in which the focal length is long, for example, the viewing angle is narrowed to about 40 ° and the depth of focus becomes shallow. The joint focus position) is moved by a distance S from the normal observation, and is brought into a state approaching, for example, about 3 mm from the surface of the observation window 11, and the observation distance for obtaining a clear observation image is in a range of about 2 to 4 mm. .

  Then, the subject mucosal surface that has been observed in the normal observation state deviates from the range of the focal depth, and a clear observation image cannot be obtained. At that time, it is difficult to perform a fine operation corresponding to a depth of focus of only about 2 mm even if the distal end body 10 is guided to an appropriate position by pushing the insertion portion 1 into the body from the hand side. It is.

  Therefore, when the distal end main body advancing / retreating lever 7 is operated in the direction in which the distal end main body advancing / retracting operation wire 81 is pushed in the operation portion 2, the distal end main body 10 is moved forward (at the distal end of the insertion portion 1 as shown in FIG. 1), if the moving distance at that time is the same as the moving distance S of the in-focus position, a clear close-up observation of the mucosal surface of the subject that was in the in-focus position during normal observation is performed. Can do.

  Therefore, as shown in FIG. 1, the maximum movement distance L in the axial direction of the tip body is equal to or longer than the maximum movement distance S of the in-focus positions of the objective optical systems 20 and 21 (that is, L ≧ If it is set to S), the distal end body 10 is moved in the axial direction in accordance with the movement of the in-focus position associated with the zoom operation, and the distance from the subject mucosal surface can be easily optimized in the close-up magnification observation. Therefore, accurate focusing can be easily performed during close-up magnification observation.

It is side surface sectional drawing of the insertion part vicinity of the zoom endoscope of the Example of this invention of the close-up magnification observation state. It is side surface sectional drawing of the insertion part front-end | tip vicinity of the normal observation state of the zoom endoscope of the Example of this invention. In the zoom endoscope of the embodiment of the present invention, it is a side sectional view of the vicinity of the distal end of the insertion portion in a state where a zoom operation for shortening the focal length from the normal observation state is performed. 1 is a side view showing an overall configuration of a zoom endoscope according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Insertion part 2 Operation part 4 Bending part 4a State-of-the-art node ring 6 Zoom operation lever (zoom operation device)
7 Tip body advancing / retracting lever (tip body advancing / retracting device)
DESCRIPTION OF SYMBOLS 10 Tip part main body 11 Observation window 20, 21 Objective optical system 25 Zoom operation wire 81 Tip part main body advance / retreat operation wire 82 Linear groove 83 Moving range regulation pin 84 Compression coil spring for biasing tip part main body (biasing means)
L Maximum travel distance in the axial direction of the tip body S Maximum travel distance of the focus position of the objective optical system

Claims (3)

The focal length is variable and the in-focus position is changed in accordance with the change in the focal length so that the close-up observation of the observation range in front of the distal-end portion main body can be performed on the distal end main body connected to the distal end of the insertion portion. A zoom endoscope in which a moving objective optical system is arranged, and a zoom operation device for performing an operation of changing a focal length of the objective optical system is arranged in an operation unit connected to a proximal end side of the insertion unit In
The distal end body is connected to the distal end portion of the insertion portion so as to be movable in the front-rear direction by a distance equal to or longer than the maximum moving distance of the focusing position of the objective optical system, and the distal end body is moved in the front-rear direction. A zoom endoscope characterized in that a distal end main body advancing / retreating device for advancing / retreating operation is arranged in the operation part. A zoom operation wire that is moved back and forth in the axial direction by the zoom operation device to change the focal length of the objective optical system is inserted in the insertion portion, and is pulled by pulling the zoom operation wire from the operation portion side. The zoom endoscope according to claim 1, wherein the focal length of the objective optical system is increased and at the same time, the in-focus state is brought into a close-up magnification observation state in which the focus position approaches the tip body. A distal end main body advancing / retreating operation wire that is advanced / retracted in the axial direction by the distal end main body advancing / retreating device is inserted and disposed in the insertion portion, and the distal end main body is inserted into the distal end portion of the insertion portion. , A biasing means for biasing in the forward direction is provided, and when the tip body main body advance / retreat operation wire is pushed out from the operation section side, the tip section main body moves forward by the biasing force of the biasing means. The zoom endoscope according to claim 1 or 2.

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