JP3969333B2 - Endoscope with objective lens moving mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is provided in an insertion portion of an endoscope used for medical purposes, and constitutes an objective optical system that constitutes an observation portion, and at least one of an imaging magnification, a viewing angle, a depth of focus, and the like is variable. Therefore, the present invention relates to an endoscope with an objective lens moving mechanism in which at least one lens constituting the objective optical system is moved in the optical axis direction by remote control.
[0002]
[Prior art]
Endoscopes used for medical purposes generally have a universal cord that is detachably connected to a body cavity insertion unit and a light source device, etc., to a main body operation unit that an operator holds and operates with a hand. Are generally configured. Due to its structure and function, the insertion part is composed of a tip part main body, an angle part and a soft part from the tip side, and the soft part has the most length from the side connected to the main body operation part. It has a structure that bends in any direction along. The distal end body is provided with an illumination section, an observation section, etc., and a treatment instrument deriving section for deriving a treatment instrument such as forceps is opened, and the angle section is for directing the distal end section body in an arbitrary direction. It can be bent by remote operation from the main body operation unit side.
[0003]
The tip body has at least an illumination part and an observation part. The illumination part faces the exit end of the light guide made up of optical fiber bundles, and this light guide passes through the body operation part from the insertion part to the universal cord. It extends to the inside. On the other hand, an objective optical system is attached to the observation unit, and a solid-state imaging device is disposed at an imaging position in the objective optical system in the case of an electronic endoscope, and an optical fiber in the case of an optical endoscope. It arranges so that the entrance end of the image guide which consists of a bundle may face. Then, the signal cable or the image guide connected to the solid-state imaging device is also inserted into the insertion portion, like the light guide. In the following description, the electronic endoscope will be described. However, if an image guide is provided instead of the solid-state imaging device and the signal cable, an optical endoscope can be obtained. In addition to these, a treatment instrument lead-out portion is opened in the distal end portion body, and a treatment instrument insertion channel made of a flexible tube is connected to the treatment tool lead-out portion, and the distal end portion body is observed. An air / water supply tube connected to a cleaning nozzle provided toward the section is inserted.
[0004]
As described above, at least the optical fiber bundle, the signal cable, the treatment instrument insertion channel, and the tubes are inserted into the insertion portion of the endoscope. Furthermore, in order to perform the bending operation of the angle portion described above, a pair of operation wires are also provided on the upper and lower sides and on the upper and lower sides and on the left and right sides, but the tips of these operation wires are fixed to the tip portion main body or its vicinity, The position is restricted in the circumferential direction, and further extends from the soft part to the main body operation part.
[0005]
Here, the endoscope objective optical system provided in the observation section is composed of a plurality of lenses, but the imaging magnification, viewing angle, depth of focus, etc. for the observation target section vary depending on the observation site and the purpose of treatment. It is desirable to do so. Therefore, a part of the plurality of lenses constituting the objective optical system is a movable lens that can move in the optical axis direction, and by moving this movable lens, the imaging magnification, viewing angle, depth of focus, etc. What was comprised so that adjustment was possible is conventionally known (for example, refer patent document 1). This known endoscope objective optical system includes two groups of movable lenses, and is configured to simultaneously move these two groups of movable lenses in the optical axis direction by a cam mechanism. When viewed from the subject side, a diaphragm is integrally formed on the movable lens frame that supports the rear group of movable lenses.
[0006]
[Patent Document 1]
JP 2001-100114 A (page 5-6, FIG. 5)
[0007]
[Problems to be solved by the invention]
By the way, in recent years, in order to improve examination and diagnosis accuracy by an endoscope, there is a tendency for a demand for a magnifying endoscope having a larger magnifying power to increase when observing the inner wall of a body cavity. . When the diaphragm is provided on the movable lens frame and moved together with the movable lens as in the prior art described above, high-quality imaging with high magnification is possible, such as the aberration of the peripheral image cannot be improved. There is a problem that it cannot be done. In order to improve aberrations, the diaphragm must be fixed alone, and must be positioned accurately at a predetermined position of the objective optical system and arranged so as to be accurately orthogonal to the optical axis. Don't be. For this reason, it is necessary to support the diaphragm stably by some member and arrange the member supporting the diaphragm so as not to interfere with the movable lens. However, from the viewpoint of operability of inserting the insertion portion into the body cavity and reducing pain of the subject, it is extremely important to reduce the diameter, and for this reason, the objective optical system provided in the insertion portion is as small as possible. Even if the aperture is fixedly provided, the objective optical system must not be increased in size as a result.
[0008]
The present invention has been made in view of the above points, and an object of the present invention is to allow a diaphragm to be fixedly incorporated independently from a movable lens or the like without particularly increasing the size of the objective optical system. There is.
[0009]
[Means for Solving the Problems]
In order to achieve the above-described object, the present invention provides a movable lens capable of moving at least one lens in the optical axis direction in order to optically change at least one of magnification, viewing angle, and depth of focus. In the endoscope with an objective lens moving mechanism having the objective optical system, the objective optical system is provided inside a housing, and the objective optical system includes a diaphragm, and the diaphragm is disposed on the diaphragm plate. is formed, the diaphragm plate, the support member is provided with connection for fixedly held in a state orthogonal to the optical axis of the objective optical system, the support member, the diaphragm An arc-shaped member extending a predetermined length in the optical axis direction from one side of the plate and having an arc-shaped outer surface of 180 ° or more , and by bringing the arc-shaped outer surface into contact with the inner surface of the housing The diaphragm plate The support member is larger than the outer diameter of the lens frame so that the lens frame of the movable lens is moved in the direction close to the diaphragm plate without interfering with the support member. It is characterized in that it is formed into a U-shape having an opening .
[0010]
Here, in order to further enhance the function of the diaphragm, it is desirable to be able to adjust the position of the diaphragm in the optical axis direction with the objective optical system incorporated. For this purpose, the support member is provided with means capable of adjusting the position of the stop in the optical axis direction. Therefore, the diaphragm plate and the support member are adjusted in position by displacing in the optical axis direction. At this time, the position adjustment range in the optical axis direction of the support member is interfered with the lenses positioned in the front and rear of the position adjustment range. It is desirable to provide a means for limiting to a range not to be performed.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Therefore, embodiments of the present invention will be described below with reference to the drawings. Needless to say, the present invention is not limited to this embodiment.
[0012]
First, FIG. 1 shows an overall schematic configuration of the endoscope. As is apparent from the figure, the endoscope 1 is generally configured by connecting an insertion portion 3 into a body cavity or the like to a main body operation portion 2 and pulling out a universal cord 4 from the main body operation portion 2. Is. The insertion portion 3 connected to the main body operation portion 2 is divided into a distal end portion main body 3a, an angle portion 3b, and a flexible portion 3c in order from the distal end side in terms of its function and structure.
[0013]
The tip portion main body 3a is made of a hard member, and is provided with the objective optical system unit 10 shown in FIGS. The objective optical system unit 10 includes an objective optical system 11, a prism 12 for bending the optical path of the objective optical system 11 by 90 ° , and an imaging unit 13 disposed at an image forming position of the objective optical system 11. Yes. The objective optical system 11 is attached to a lens holding frame 14 fixedly held in the objective optical system unit 10 and attached to a subject side fixed lens group 15 including one or several lenses, and a lens holding frame 16. An imaging-side fixed lens group 17 composed of one or a plurality of lenses, and a subject-side movable lens composed of one or a plurality of lenses each movable in the optical axis direction between these fixed lens groups 15 and 17. It is composed of a group 18 and image forming side movable lens groups 19.
[0014]
The prism 12 is for bending the optical axis of the objective optical system 11 by 90. The imaging means 13 is composed of a solid-state imaging device disposed at the image forming position of the objective optical system 11 and its substrate, and a number of wirings are connected to the substrate. These wirings are flexible tubes, tapes, etc. Are extended from the insertion portion 3 through the main body operation portion 2 into the universal cord 4.
[0015]
The two sets of movable lens groups 18 and 19 constituting the objective optical system 11 are movable lenses movable in the optical axis direction. These movable lens groups 18 and 19 are attached to the movable lens frames 20 and 21. ing. Arms 22, 23 are connected to the movable lens frames 20, 21, and ring members 24, 25 are formed at the distal ends of these arms 22, 23. A cam shaft 26 is provided at a position parallel to the optical axis of the objective optical system 11 and away from the objective optical system 11, and cam grooves 27a, 27b is formed. The ring members 24 and 25 are provided with cam pins 28a and 28b that engage with the cam grooves 27a and 27b, respectively. Accordingly, when the cam shaft 26 is rotated in the forward / reverse direction, the cam pins 28a and 28b engaged with the cam grooves 27a and 27b slide or roll along the cam grooves 27a and 27b. The movable lens groups 18 and 19 attached to the movable lens frames 20 and 21 connected via the ring members 24 and 25 and the arms 22 and 23 are displaced in the optical axis direction.
[0016]
Here, the two cam grooves 27 a and 27 b have a predetermined length in the circumferential direction and are inclined at a predetermined angle with respect to the axis of the cam shaft 26. In addition, the inclination angles of the cam grooves 27a and 27b are different. Therefore, when the cam shaft 26 is rotated, the movable lens groups 18 and 19 move differently. Here, if the inclination angles of the cam grooves 27a and 27b are reduced, smooth movement is possible. However, if the angle is too small, the length of the cam groove must be increased. The outer diameter of the shaft 26 is increased. On the other hand, when the angles of the cam grooves 27a and 27b are increased, the movement of the movable lens groups 18 and 19 becomes heavier and the load during driving increases. Accordingly, the angles of the cam grooves 27a and 27b are set within a range of 5 to 30 ° so that a necessary angle difference is provided therebetween. In order to rotationally drive the camshaft 26, a rotational drive means (not shown) such as an electric motor or a flexible shaft is connected to the base end portion of the camshaft 26.
[0017]
As shown in FIG. 4, the housing 30 of the objective optical system unit 10 includes an objective optical system mounting portion 31 and a driving means mounting portion 32 each having a substantially cylindrical shape, and these objective optical system mounting portions. The connecting portion between the driving means 31 and the drive means mounting portion 32 has a regulating wall portion 33 whose inner surface abuts against the side portions of the movable lens frames 20 and 21 and prevents them from rotating, thereby camming. When the shaft 26 is rotated, the arms 22 and 23 connected to the movable lens frames 20 and 21 are in sliding contact with the restriction wall 33, and the movable lens groups 18 and 19 on the subject side and the imaging side are in the optical axis direction. It moves only to, and demonstrates functions such as zooming.
[0018]
A diaphragm plate 34 is disposed between the movable lens frames 20 and 21. The diaphragm plate 34 is made of a thin plate material, and a diaphragm 34 a having a predetermined aperture diameter is formed at the center position of the optical axis of the objective optical system 11. The diaphragm plate 34 is mounted independently of the movable lens frames 20 and 21 so as not to fall down or shift with respect to the optical axis.
[0019]
Thus, in order to hold the diaphragm plate 34 in a fixed position between the movable lens frames 20 and 21, the diaphragm plate 34 is integrally provided with a support member 35 formed in a substantially U shape. ing. As shown in FIGS. 5 and 6, the support member 35 is a member whose outer peripheral surface having a thickness larger than the plate thickness of the diaphragm plate 34 has an arc shape, and in the optical axis direction, the subject side fixed lens group 15. The outer peripheral surface of the housing 30 is in close contact with the inner surface of the objective optical system mounting portion 31. The contact portion of the outer peripheral surface of the support member 35 with the inner surface of the objective optical system mounting portion 31 is at an angle of 180 ° or more in the circumferential direction. As a result, the diaphragm plate 34 is stably supported so as not to tilt or fall over the optical axis.
[0020]
As a result of extending the support member 35 toward the lens holding frame 14, the movable lens frame 20 to which the subject-side movable lens group 18 is attached and the arm 22 provided integrally therewith are disposed inside the support member 35. Become. Since the movable lens frame 20 moves in the optical axis direction for zooming or the like, it is necessary to prevent the support member 35 from interfering with the movable lens frame 20 and its arm 22. The upper end portion of the support member 35, that is, the side connected to the regulation wall portion 33 has an opening 35 a that is at least larger than the outer diameter of the movable lens frame 20. If the opening 35 a does not face directly above, the edge of the support member 35 may interfere with the arm 22. Therefore, when the diaphragm plate 34 provided integrally with the support member 35 is incorporated in the objective optical system 11, the position adjustment in the rotation direction must be performed. For this purpose, a pair of left and right slits 36 is formed at the front end of the support member 35, that is, the end on the front side in the optical axis direction, and a predetermined jig is inserted into the slit 36 to rotate in the rotation direction. The position can be adjusted.
[0021]
Further, the diaphragm plate 34 is incorporated in a position adjusted in the optical axis direction at a position between the subject side movable lens group 18 and the imaging side movable lens group 19. In order to enable adjustment of the position of the diaphragm plate 34 in the optical axis direction in the assembled state, an adjustment groove 37 is formed on the outer peripheral surface of the support member 35 so that a position adjusting jig can be engaged. Has been. Further, the objective optical system mounting portion 31 in the housing 30 has a through hole 38 formed in a part of the joint portion of the support member 35, and a jig is inserted into the adjustment groove 37 from the through hole 38. The position of the diaphragm plate 34 can be adjusted by engaging and pushing in the optical axis direction.
[0022]
However, in order to adjust the aperture position, the amount of movement of the aperture plate 34 must be limited to some extent. If it is possible to move indefinitely, the diaphragm plate 34 may come into contact with the movable lens groups 18 and 19 when the position is adjusted, and the lens surface may be damaged. In order to prevent this, the movement range of the diaphragm plate 34 is limited. The movement range is limited by the end surface on the opposite side to the support member 35 of the lens frame 14 of the subject side fixed lens group 15 and the step portion 31 a formed on the inner surface of the objective optical system mounting portion 31. That is, the support member 35 is movable in the front-rear direction between the end face of the lens frame 14 and the step portion 31a.
[0023]
The configuration of the objective optical system unit 10 with the lens moving mechanism in the endoscope is as described above. As shown in FIG. 2, the subject-side movable lens group 18 and the imaging-side movable lens group 19 include an aperture plate. By rotating the cam shaft 26 and separating the movable lens groups 18 and 19 from a state where they are arranged close to each other with the 34 interposed therebetween, the imaging magnification is increased, and the magnifying endoscope is obtained. It becomes possible to magnify and image the inner wall of the body cavity. Moreover, since the diaphragm plate 34 is in a stationary state regardless of the movement of both the movable lens groups 18 and 19, the aberration does not increase at the time of zooming, and a clear image can be obtained.
[0024]
Next, a method for incorporating the diaphragm plate 34 will be described. First, in the objective optical system 11, the imaging-side fixed lens group 17 and its lens holding frame 16, and the imaging-side movable lens group 19 and its lens frame 21, arm 23 and ring member 25 are mounted in the housing 30. Then, the ring member 25 is connected to the cam shaft 26. In this state, the diaphragm plate 34 and its support member 35 are inserted from the front of the objective optical system mounting portion 31 and sent to a position where they come into contact with the step portion 31a. Here, since the support member 35 slides along the inner surface of the objective optical system mounting portion 31, the diaphragm plate 34 does not tilt or shift with respect to the optical axis. However, misalignment may occur in the rotational direction. Therefore, a jig is inserted into the slits 36 and 36 formed at the tip of the support member 35 and rotated so that the opening 35a of the support member 35 faces a predetermined direction, that is, directly above in FIG. Adjusted. Thereafter, the subject-side movable lens group 18 and the subject-side fixed lens group 15 are incorporated.
[0025]
In this state, the diaphragm plate 34 and the support member 35 provided integrally therewith are not fixed to the objective optical system mounting portion 31 and can be moved in the direction of the lens frame 14 of the subject side fixed lens group 15. . Therefore, the subject is actually photographed by the imaging means 13. At this time, a jig is inserted through the through-hole 38 of the objective optical system mounting portion 31 and engaged with the adjustment groove 37 to move the support member 35 back and forth in the optical axis direction. As a result, when the clearest image is obtained, the jig is extracted from the through hole 38 at that position, and the through hole 38 is filled with an adhesive. As a result, the diaphragm plate 34 is fixedly held at the most desirable position.
[0026]
【The invention's effect】
Since the present invention is configured as described above, there is an effect that the aperture can be fixedly incorporated at a predetermined position independently of the movable lens without significantly increasing the size of the objective optical system.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an endoscope showing an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a configuration of an objective optical system unit.
3 is a cross-sectional view showing an operating state of the objective optical system unit of FIG. 2;
4 is a cross-sectional view taken along line XX in FIG.
FIG. 5 is a front view showing a diaphragm plate and its supporting member.
6 is a left side view of FIG. 5. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Endoscope 2 Main body operation part 3 Insertion part 10 Objective optical system unit 11 Objective optical system 14,16 Lens holding frame 15 Subject side fixed lens group 17 Imaging side fixed lens group 18 Subject side movable lens group 19 Imaging side movable Lens group 20, 21 Movable lens frame 22, 23 Arm 24, 25 Ring member 26 Cam shaft 28 a, 28 b Cam pin 30 Housing 31 Objective optical system mounting portion 31 a Stepped portion 32 Drive means mounting portion 33 Restricting wall portion 34 Aperture plate 34 a Aperture 35 Support member 35a Opening 36 Slot 37 Adjustment groove 38 Through hole

Claims (4)

Internal vision with an objective lens moving mechanism having an objective optical system in which at least one lens is movable in the optical axis direction in order to optically change at least one of magnification, viewing angle, and depth of focus. In the mirror
The objective optical system is provided inside the housing,
The objective optical system includes a diaphragm, and the diaphragm is formed on a diaphragm plate.
The diaphragm plate is provided with a support member that is fixedly held in a state orthogonal to the optical axis of the objective optical system ,
The support member is an arc-shaped member that extends a predetermined length from one side of the diaphragm plate in the optical axis direction and has an arc-shaped outer surface of 180 ° or more . By holding the diaphragm plate in contact with the inner surface,
In order to move the lens frame of the movable lens in a direction close to the diaphragm plate without interfering with the support member, the support member has a U-shape having an opening larger than the outer diameter of the lens frame. An endoscope with an objective lens moving mechanism, characterized in that the endoscope is formed in a shape .   The endoscope with an objective lens moving mechanism according to claim 1, wherein the support member includes means capable of adjusting a position of the diaphragm in the optical axis direction.   3. The internal view with an objective lens moving mechanism according to claim 2, further comprising means for limiting a position adjustment range of the support member in the optical axis direction to a range in which the support member does not interfere with a lens positioned in front of and behind the support member. mirror. The lens frame of the movable lens is connected to driving means via an arm portion, and the housing is mounted with the objective optical system mounting portion having the inner surface on which the objective optical system is mounted and the support member abuts. The endoscope with a lens moving mechanism according to any one of claims 1 to 3, wherein the endoscope has a driving means mounting portion on which a driving means is mounted.

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