JPH09192084A - Endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a focusing accurately in an endoscope by adjusting the position of a photodetecting means with respect to an objective optical system. SOLUTION: A support tube 40 housing an objective optical system 42 is housed into the tip part of an inserting part 10 of a body 1. The rear end part of the support tube 40 is linked to the tip part of a guide tube 50. A holder 60 is housed at the front part of the guide tube 50 movably in the axial direction but unable to rotate. An adjusting member 70 is housed at the rear part of the guide tube 50 unmovably in the axial direction but able to rotate. The rear end part of the holder 60 is thread-linked to the tip part of the adjusting member 70. By turning a knob 71 (rotary operation part) at the rear end of the adjusting member 70, the position of the holder 60 is adjusted axially and ultimately, an image sensor 65 (photodetecting means) held at the tip of the holder 60 is positionally adjusted with respect to the objective optical system 42.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope in which the positional relationship between an objective optical system and a light receiving means can be adjusted so that focusing can be performed.

[0002]

2. Description of the Related Art An endoscope has a body having a hollow base portion and a hollow insertion portion extending forward from the base portion. An objective optical system is housed in the tip of the insertion section. An image sensor (light receiving means) such as a CCD is arranged behind the objective optical system. A signal line (image transmitting means) is connected to the image sensor, and the signal line is led to the outside through the insertion portion and the base portion. An image of an observation target is picked up by an image sensor through an objective optical system, an image signal of the image is sent to a processing device through a signal line, converted into a television signal here, and displayed on a television.

[0003]

In the conventional general endoscope described above, the positional relationship between the objective optical system and the light receiving means is constant, and the focusing can be performed according to the distance to the observation object. There wasn't. Therefore, an endoscope capable of focusing was developed, but none was satisfactory.

For example, in the endoscope disclosed in Japanese Utility Model Publication No. 46-18123, a holder for holding the tip of an optical fiber bundle (image transmitting means) is accommodated inside an insertion portion so as to be movable in the axial direction. There is. This holder is prohibited from rotating by a pin. On the other hand, the body is provided with a seesaw type operating member, and by operating this operating member,
Focusing is performed by moving the holder via a wire to adjust the position, and then adjusting the position of the tip end surface (light receiving means) of the optical fiber bundle with respect to the objective optical system. However, with this endoscope, the position of the holder can be selected only from two positions, a front position and a rear position,
Since it is not possible to make fine adjustments, high-precision focusing could not be expected.

In the endoscope disclosed in FIG. 2 of Japanese Utility Model Laid-Open No. 60-16115, the rear end of an image guide (image transmitting means) formed by fixing and integrating optical fiber bundles is fixed to an eyepiece tube. Has been done. The eyepiece tube is inserted into the body such that it cannot rotate but can slide in the axial direction. In this configuration, the axial position of the distal end surface (light receiving means) of the rigid image guide is adjusted with respect to the objective optical system by moving the eyepiece tube in the axial direction with respect to the body. But,
Fine adjustment is difficult because the axial movement amount of the eyepiece tube directly becomes the positional adjustment amount of the tip end surface of the image guide. Further, since there is no means for holding the adjusted position of the image guide, it is necessary to always hold the eyepiece tube by hand, and the operation is complicated.

The above-mentioned Japanese Utility Model Publication No. 60-16115 discloses that
Other embodiments are also described in which the eyepiece is screwed onto the body. However, in this embodiment, although the position of the front end surface of the image guide can be finely adjusted, the image guide rotates during this position adjustment, and the positional relationship between the vertical and horizontal directions in the visual field changes. was there.

[0007]

Means for Solving the Problems The invention of claim 1 is:
(A) A body having a hollow hard insertion portion extending long,
(B) an illumination light transmitting means having a tip portion arranged in the tip portion of the insertion portion and extending rearward through the insertion portion;
An objective optical system arranged in the distal end of the insertion section,
(D) A light receiving unit which is arranged behind the objective optical system and receives reflected light from the observation object through the objective optical system; and (e) the image information received by the light receiving unit, which passes through the insertion section, is sent backward. An endoscope comprising: an image transmitting means; (f) a holder for holding the light receiving means; and (g) a position adjusting means for adjusting the position of the holder in the axial direction with respect to the objective optical system, The position adjusting means includes a first locking means that locks the holder axially movable with respect to the insertion portion and non-rotatably, and a tip end portion extending in the axial direction of the insertion portion and a rear end portion of the holder. It has an adjusting member to be screwed and a second locking means for locking the adjusting member so as to be rotatable with respect to the body and axially immovable, and the holder causes the shaft to rotate as the adjusting member rotates. It is characterized in that the position is adjusted in the direction.

According to a second aspect of the present invention, in the endoscope according to the first aspect, the holder and the adjusting member have a tubular shape, and the image transmitting means is inserted into the inside thereof. . According to a third aspect of the present invention, in the endoscope according to the first or second aspect, the insertion portion includes a guide tube extending in the axial direction, and the holder and the adjusting member are housed in the guide tube and the first section is provided. , And the guide tubes are respectively locked by the second locking means.

According to a fourth aspect of the present invention, in the endoscope according to the third aspect, the first locking means has a housing hole having a non-circular cross section formed at the distal end portion of the guide tube and the housing hole. And a head portion of a holder having a non-circular cross section housed therein. According to a fifth aspect of the present invention, in the endoscope according to the third aspect, the second locking means is provided in an annular groove formed on the outer periphery of the adjusting member and is inserted into the annular groove provided in the guide tube. It is characterized by being configured with a pin. According to a sixth aspect of the invention, in the endoscope according to the third aspect, the second locking means is a spring that biases the holder forward, and a protrusion that is provided on the adjustment member and contacts the rear end of the guide tube. It is characterized by being configured with a section.

According to a seventh aspect of the present invention, in the endoscope according to the third aspect, the rear end portion of the adjusting member is provided as a rotating operation portion so as to project to the outside. Claim 8
The invention according to claim 3 is the endoscope according to claim 3, further comprising:
An operation member that is rotatably inserted in the rear end portion of the guide tube so as not to move in the axial direction is provided, and the rear end portion of the operation member is provided as a rotation operation portion by protruding to the outside. And a rear end portion of the adjusting member is connected so as to be movable in the relative axial direction and not relatively rotatable. According to a ninth aspect of the present invention, in the endoscope according to the third aspect, the objective optical system is supported in a support tube, the support tube is detachably housed in the insertion section, and the guide tube is provided in the insertion section. It is housed so that it can slide axially,
A rear end portion of the support pipe is detachably connected to a front end portion of the guide pipe.

According to a tenth aspect of the present invention, in the endoscope including the constituent elements (a) to (g) according to the first aspect, the objective optical system is provided in a support tube as one constituent element of the position adjusting means. Supported, the position adjusting means further includes first locking means for allowing the support tube to rotate and locking the tip of the support tube to prohibit forward movement, and the holder with respect to the insertion portion. Second locking means for axially movable but non-rotatably locked, a spring for urging the holder toward the support tube, a rear end of the support tube and a tip of the holder in cooperation with each other. Cam means for adjusting the position of the holder in the axial direction according to the rotation of the pipe.

According to a tenth aspect of the present invention, in the endoscope according to the tenth aspect, the first locking means includes a locking convex portion provided in the insertion portion and protruding in the radial and inward directions. By locking the tip of the support tube to the locking projection, the forward movement of the support tube is prohibited, and moreover, the tip of the support tube has a plurality of engaging recesses along the circumferential direction. It is characterized in that the rotational position of the support tube is maintained by engaging one of the engaging concave portions with the locking convex portion. According to a twelfth aspect of the present invention, in the endoscope according to the eleventh aspect, a passage groove that extends in the axial direction is formed on the outer periphery of the support tube, and the passage groove is the tip of the insertion portion of the support tube. It is characterized in that it is used for passing the locking convex portion when inserting and removing the portion.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIG. FIG. 1A shows a rigid endoscope. This rigid endoscope includes a hollow body 1. This body 1 has a rigid insertion portion 10 extending linearly.
And a base portion 20 provided at the rear end of the insertion portion 10.

The insertion portion 10 has a hard outer tube 11 and an inner tube 12 which are coaxial with each other and have a circular cross section. The tips of the outer tube 11 and the inner tube 12 coincide with each other. The inner space of the inner tube 12 is provided as the first accommodation space 13. The annular space between the outer pipe 11 and the inner pipe 12 is the first accommodation space 1
It surrounds 3 coaxially and is provided as the 2nd accommodation space 14. The rear end portion of the outer tube 11 is inserted and fixed to the front wall of the base portion 20. The rear end portion of the inner pipe 12 passes through the internal space of the base portion 20 and is inserted and fixed to the rear wall of the base portion 20.

An optical fiber bundle 30 (illumination light transmitting means) for transmitting illumination light is accommodated in the second accommodation space 14,
It extends in the axial direction. The tip of the optical fiber bundle 30 is substantially aligned with the tips of the outer tube 11 and the inner tube 12. The optical fiber bundle 30 passes through the base portion 20 from the rear end of the second housing space 14 and is led out to the outside, and the rear end is connected to a light source device (not shown).

An objective unit 40 is housed in the tip of the first housing space 13. This objective unit 40
Has a cylindrical support tube 41 and an objective optical system 42 accommodated and supported inside the support tube 41. The objective optical system 42 includes a glass plate 42a, a diaphragm plate 42b, and a plurality of, for example, 3 pieces in order from the front end of the support tube 41 toward the rear.
It has two lenses 42c. On the outer periphery of the tip of the support pipe 41, an annular locking projection 4 is formed which projects radially and outwardly.
5 are formed. On the other hand, the inner pipe 12 projects radially and inwardly at a position slightly retracted from the tip.
A single or a plurality of locking projections 15 are formed. The locking projections 45, 15 constitute a locking means for positioning. That is, the locking convex portion 45 of the support tube 41 hits the locking convex portion 15 of the inner tube 12, whereby the rearward movement of the objective unit 40 is restricted and the objective unit 40 is positioned. The tip end substantially coincides with the tip end of the insertion portion 10.

On the other hand, a cylindrical attachment tube 21 is attached to the base portion 20. This mounting cylinder 21
It is inserted at the rear end of the inner tube 12. A flange portion 21a is formed at the rear end of the mounting cylinder 21.
a is fixed to the rear wall of the base portion 20. A screw hole 21b penetrating in the radial direction is formed in the flange portion 21a, and a screw 22 that functions as described later is screwed into the screw hole 21b.

A guide tube 50 is slidably and detachably inserted in the mounting cylinder 21 in the axial direction.
The guide tube 50 is made of a hard tube and extends through the mounting cylinder 21 in the first housing space 13 coaxially with the insertion portion 10. The rear end portion of the guide tube 50 projects rearward from the rear wall of the base portion 20 and the mounting cylinder 21, and a large-diameter knob portion 51 is formed therein. The front end of the guide tube 50 is screwed to the rear end of the support tube 41. A key 55 protruding in the radial direction and the outward direction is fixed to the guide tube 50.
It is housed in a key groove 21c formed on the inner surface of the shaft and extending in the axial direction. As a result, when the screw 22 is loose, the guide tube 50 can move in the axial direction and cannot rotate.

In the guide tube 50, a tube-shaped holder 60 is housed in the front part thereof and a tube-shaped adjusting member 70 is housed in the rear part thereof. The holder 60 has a head portion 61 at its tip, and this head portion 61 is non-circular, for example, rectangular, and is accommodated in a accommodation hole 52 having a rectangular cross section (non-circular shape) formed in the tip portion of the guide tube 50. ing. The head portion 61 and the accommodating hole 52 constitute a first locking means that locks the holder 60 with respect to the guide tube 50 so as to be axially slidable and non-rotatable. The accommodation hole 5
A spring 56 is accommodated in the head 2, and a head portion 61
The spring 56 may be omitted.

The rear end of the adjusting member 70 projects from the rear end of the guide tube 50, and a large-diameter knob portion 71 (rotating operation portion) is formed there. The adjusting member 70 has an annular groove 72 on the outer periphery of the rear end portion, and the annular groove 72 is provided in the annular groove 72.
The tip of a pin 53 that radially penetrates the knob portion 51 of 0 is inserted. The pin 53 and the annular groove 72 lock the operating member 50 with respect to the guide tube 50 (and thus with respect to the body 1) so as not to move in the axial direction and to be locked.
It constitutes a locking means. The rear end portion of the holder 60 and the front end portion of the adjusting member 70 are screwed together in the guide tube 50.

For the holder 60, which has the function described below, the first locking means consisting of the head portion 61 and the accommodation hole 52, the second locking means consisting of the pin 53 and the annular groove 72, and the adjusting member 70. The position adjusting means 5 is constructed.

A concave portion 61a is formed on the tip surface of the head portion 61 of the holder 60, and an image sensor 65 (light receiving means) such as a CCD is accommodated in the concave portion 61a. A tip of a signal line 66 (image transmitting means) is connected to the image sensor 65. The signal line 66 extends through the holder 60 and the adjusting member 70 from the rear end to the outside. The rear end of the signal line 66 is connected to the monitor television via the processing device.

In the above configuration, the objective unit 40 and the guide tube 50 are positioned in a state in which the locking projection 45 of the objective unit 40 is locked and positioned by the locking projection 15 of the insertion section 10.
Are connected by screwing, and the guide tube 50 is fixed to the base member 20 by screws 22. As a result, the objective unit 40 is maintained at a predetermined position with respect to the body 10. In this state, when the knob 71 of the adjusting member 70 is pinched and the adjusting member 70 is rotated, the adjusting member 70 cannot move axially with respect to the base portion 20, and the holder 60 rotates with respect to the guide tube 50. Immobility,
Through the screwing of the adjusting member 70 and the holder 50, the holder 50
Are axially aligned. As a result, the image sensor 65 held at the tip of the holder 50 moves to the objective optical system 42.
The position is adjusted in the axial direction with respect to, whereby focusing can be performed. By utilizing the screwing of the holder 60 and the adjusting member 70, it is possible to finely adjust the position of the holder 60 by the turning operation of the adjusting member 70. Therefore, highly accurate focusing can be performed. it can. Also, at the time of focusing, the image sensor 6
Since 5 does not rotate, it is possible to avoid changes in the vertical and horizontal positions in the visual field, which does not hinder observation.

The objective unit 40 can be removed from the insertion portion 10 of the body 1, that is, replaceable. In a state where the objective unit 40 is not attached, the guide tube 50 is advanced with respect to the body 1 until the knob portion 51 hits the rear wall of the base portion 20, and the tip thereof is positioned near the tip of the insertion portion 10. .

When the objective unit 40 is attached to the insertion portion 10, the screw 22 is loosened so that the guide tube 50 can slide with respect to the body 1. In this state, the objective unit 40
Is brought close to the tip of the guide tube 50, and the rear end of the support tube 41 is screwed onto the tip of the guide tube 50. This screw is
This is performed by rotating the objective unit 40. At this time, the guide tube 50 is prevented from rotating by the key 55 and the key groove 21c.

Next, the guide tube 50 is slid backward. At this time, the holder 60, the adjusting member 70, and the image sensor 65 also move together with the guide tube 50. Eventually, the locking convex portion 45 at the tip of the objective unit 40 hits the locking convex portion 15 of the inner tube 12, the rearward movement of the objective unit 40 and the image sensor 65 is prohibited, and their positioning is performed. At this position, the screw 22 is screwed in to fix the guide tube 50. In this positioning state, the tip of the objective unit 40 substantially coincides with the tip of the insertion section 10 and also substantially coincides with the tip of the optical fiber bundle 30. Then, if the above-described focusing is performed after the objective unit 40 is mounted, the observation target at an arbitrary distance can be focused.

When the objective unit 40 is to be removed, the screw 22 is loosened to move the guide tube 50 forward and the objective unit 40 protruding from the tip of the insertion portion 10 is reversed.
The screwed state with the guide tube 50 may be released by grasping and turning by hand.

Instead of the objective unit 40, FIG.
The objective unit 40A of (B) can be attached to the body 1. In this objective unit 40A, FIG.
The components corresponding to the objective unit 40 shown in FIG. The objective optical system 42A of the objective unit 40A is for obtaining a wide-angle field of view,
A concave lens 42d is attached to the tip of the support tube 41A instead of the glass plate 42a. The axial dimension of the objective unit 40A is the same as the objective unit 4 of FIG.
Longer than zero. Therefore, when the objective unit 40A is mounted, the image sensor 65 retracts from the tip of the insertion portion 10 as compared with the case of FIGS. Such a dimensional difference in the axial direction can be absorbed by sliding the guide tube 50. The objective unit 40A is positioned by the engagement of the engagement protrusions 45 and 15.

After the replacement of the objective unit 40A, the adjusting member 70 is pivotally operated in the same manner as described above to perform focusing. As the objective unit, a side-viewing unit or the like can be used as well.

Another embodiment of the present invention will be described below. In these embodiments, the components corresponding to those in the preceding embodiment are designated by the same reference numerals and the description thereof will be omitted. In FIG. 2, the second
An example will be described. In this embodiment, the holding means for the guide tube 50 differs from the first embodiment described above. The details will be described below.

A stepped annular spring receiving portion 58 is formed at an intermediate portion of the guide tube 50, and an annular spring receiving portion 16 protruding radially and inward is provided at a middle portion of the inner tube 11. Are formed. A coil spring 80 in a compressed state is interposed between the spring receiving portions 58 and 16.

In the vicinity of the knob portion 51 of the guide tube 50,
A locking protrusion 59 is provided. Further, an annular groove 25 and a passage groove 26 extending in the axial direction so as to pass from the annular groove 25 to the rear surface of the base portion 20 are formed on the inner peripheral surface of the base portion 20.

In the above structure, in the state before the objective unit 40 is mounted, the guide tube 50 is at the position where the knob portion 51 is in contact with the rear surface of the base portion 20, that is, the forward position, and the image sensor 65 is exposed to the outside. ing. At this time, the locking convex portion 59 of the guide tube 50 is housed in the annular groove 25 of the base portion 20, and the guide tube 50 is prohibited from moving rearward against the biasing force of the coil spring 80. .

Next, the objective unit 40 is screwed into the guide tube 50. After this screwing is completed, the guide tube 50 is rotated so that the locking projection 59 is aligned with the passage groove 26. As a result, the guide tube 50 moves rearward by the biasing force of the coil spring 80. Then, the locking projection 4 of the objective unit 40
By locking 5 to the locking projection 15 of the inner tube 12, the rearward movement of the objective unit 40 and the guide tube 50 is restricted, and the objective unit 40 is positioned.

In this state, the coil spring 80
Is in a compressed state and always biases the guide tube 50 rearward. Since the guide tube 50 is restricted from moving rearward by the locking projections 15 and 45, the guide tube 50 is stably supported. The focusing is the same as in the first embodiment.

In the third embodiment shown in FIG. 3, the guide tube 15
0 does not project to the rear of the base portion 20 and is connected to the rotating member 152, which is a great difference from the first embodiment.
The rotating member 152 is provided as a part of the guide tube. The front end of the guide tube 150 is screwed to the rear end of the support tube 41 of the objective unit 40. A keyway 150 is formed on the outer circumference of the guide tube 150.
a is formed. The inner pipe 1 is provided in the key groove 150a.
A key 17 that projects radially and inwardly from the inner peripheral surface of the housing 2 is housed. As a result, the guide tube 150 is not rotatable with respect to the insertion portion 10 and is movable in the axial direction.

An annular spring receiving portion 150b extending radially and inward is provided a predetermined distance before the rear end of the guide tube 150.
Are formed. The inner tube 12 is further formed with a spring receiving portion 18 that projects radially and inwardly.
A coil spring 85 that biases the guide tube 150 rearward is provided between the portions 50b and 18.

On the other hand, the rotating member 152 is inserted through the base portion 20. The rear end of the rotating member 152 projects to the outside, and a large-diameter knob portion 152a is formed there. An annular groove 152b is formed in the knob portion 152a. When the pin 22m screwed into the base portion 20 enters the annular groove 152b, the rotating member 1
The reference numeral 52 is only capable of turning, and is prohibited from moving in the axial direction.

The rear end of the guide tube 150 has a rotating member 152.
Of the cam mechanism 155. The cam mechanism 155 is used for the guide tube 1
The pin 50 has a pin 156 provided at the rear end of the pin 50 and projecting radially and outwardly, and a spiral groove 157 formed in the peripheral wall of the tip of the rotating member 152 to accommodate the pin 156.

In the above structure, in the state before the objective unit 40 is mounted, the pin 156 of the guide tube 150 is at the tip of the spiral groove 157 of the rotating member 152 or in the vicinity thereof, and as a result, the guide tube 150 is at the forward position. The image sensor 65 is located near the tip of the insertion section 10.

In this state, the objective unit 40 is attached to the guide tube 1
It is screwed to the tip of 50. At this time, since the rotation of the guide tube 150 is prohibited, the screwing can be advanced by rotating the objective unit 40. After the screwing is completed, the rotating member 152 is rotated. At this time, since the guide tube 150 is prohibited from rotating as described above, the cam action of the spiral groove 157 and the pin 156 causes the guide tube 1 to move.
50 moves backwards. Eventually, the locking projection 45 of the objective unit 40 is locked to the locking projection 15 of the inner tube 12, whereby the rearward movement of the objective unit 40 and the guide tube 150 is restricted, and the positioning of the objective unit 40 is performed. Done.

In this state, the coil spring 85 in the compressed state biases the guide tube 150 rearward, so that the pin 156 hits the wall of the spiral groove 157, and the friction thereof causes the guide tube 150 and the rotating member 152 to engage with each other. Stable support at the stop position. As in the first embodiment, instead of the objective unit 40, an objective unit 40A shown in FIG. 1 (B) may be attached.

In the third embodiment, the adjusting member 171 is
It is shorter than the adjusting member 70 of the first embodiment and does not protrude to the outside. The adjusting member 70 is inserted into the rotating member 152 and the guide tube 150. Both members 171, 17
Both 2 have a tubular shape and allow the signal line 66 to be inserted therethrough. The adjusting member 171 is screwed to the rear end of the holder 60 at the front end. A locking brim 171x (projection) is formed in the middle of the adjusting member 171. The holder 60 and the adjustment member 171 are urged forward by the spring 56, and the locking flange 171x abuts the rear end surface of the guide tube 150, whereby the adjustment member 171 moves axially with respect to the guide tube 150. Is prohibited and is allowed to rotate. Therefore, the spring 56 and the locking collar 171 are
x constitutes the second locking means.

The rear end portion of the adjusting member 171 is a rod portion 171a having a rectangular cross section, and this rod portion 171a.
Is inserted into an engaging hole 172a having a rectangular cross section formed at the tip of the operating member 172. The rear end of the operating member 172 projects from the rear end of the rotating member 152, and a large-diameter knob portion 172b (rotating operation portion) is formed there. An annular groove 172c is formed on the outer periphery in the vicinity of the knob portion 172b.
Is formed in the annular groove 172c.
The pin 53 provided on the
The operation member 172 is rotatable and is locked so as not to move in the axial direction.

In the third embodiment described above, focusing can be performed by turning the operating member 172. That is, when the operation member 172 is rotated, the adjustment member 171 also rotates through the engagement between the engagement hole 172a and the rod portion 171a,
As a result, the holder 60 is axially adjusted in position by screwing the adjusting member 171 and the holder 60 together.

When the objective unit 40 is mounted and the guide tube 150 is retracted, the guide tube 15
Operation member 170 locked to 0 via a locking collar 171x
The adjusting member 171 also moves backward. This adjusting member 17
1 is moved to the rear by moving the rod portion 171a and the engaging hole 172.
It is allowed by the engagement of a.

In the fourth embodiment shown in FIGS. 4 to 6,
Unlike the third embodiment, the focusing operation is performed at the tip of the insertion section 10 side. The details will be described below. Holder 160
Is much shorter than the insertion portion 10 and is arranged near the tip of the insertion portion 10. The inner tube 12 is used as a guide tube that guides the holder 160 slidably in the axial direction. The holder 160 holds the image sensor 65 at its tip. A coil spring 88 in a compressed state is interposed between the rear end of the holder 160 and an annular spring receiving portion 12x formed on the inner circumference of the inner tube 12, and the coil spring 88 causes the holder 160 to move. It is biased forward.

A key groove 161 extending in the axial direction is formed on the outer periphery of the holder 160, and the key groove 161 is formed.
A key 12y that is formed on the inner circumference of the inner pipe 12 and protrudes inward in the radial direction is inserted into the inside. This keyway 161
The key 12y constitutes a second locking means that locks the holder 160 so that it can move in the axial direction and cannot rotate.

In this embodiment, there is no guide tube, and therefore the support tube 41B of the objective unit 40B is not screwed to the guide tube. In this embodiment, the inner pipe 12 plays a role of a guide pipe for guiding the holder. Support tube 41
An annular step 45 is formed near the tip of B. The step 45 is engaged with a retaining projection 12z formed on the inner peripheral surface near the tip of the inner pipe 12 and protruding inward in the radial direction. The step 45 and the locking projection 12z constitute a first locking means for restricting the forward movement of the support tube 41B.

A large number of engagement recesses 45a are formed side by side in the circumferential direction on the step 45. The engagement recesses 45a and the locking projections 12z rotate the support pipe 41B as will be described later. Maintaining means are configured to maintain the position.

On the tip end surface of the support tube 41B, a knob portion 46 (operation portion) for rotating the support tube 41B is formed. Further, a passage groove 49 extending in the axial direction is formed on the outer periphery of the support pipe 41B.

The rear end of the support tube 41B and the holder 1
The tip portion of 60 is linked by the cam means 90. The cam means 90 includes an inclined cam surface 91 formed on the rear end of the support tube 41B and a follower pin 92 formed on the outer circumference of the front end of the holder 160 and protruding radially and outwardly. The follower pin 92 contacts the inclined cam surface 91 by the force of the coil spring 88.

In this embodiment, the support pipe 41B is used.
A spring 88, a first locking means including a step 45 and a locking projection 12z, a second locking means including a key groove 161 and a key 12y, an engaging recess 45a and the locking projection 12z.
The position adjusting means for the holder 160 is constituted by the maintaining means consisting of and the cam means 90.

In the above structure, when the objective unit 40B is not mounted, the holder 160 is attached to the coil spring 88.
Is in the forward movement position due to the force of, and the tip floor pin 92 is locked to the locking projection 12z at the tip of the inner tube 12.

The objective unit 40B is mounted as follows. That is, the first resistance is exerted against the coil spring 88.
It is inserted from the front end opening of the accommodation space 13. At this time, the locking projection 12z passes through the passage groove 49, so that the objective unit 40B can be inserted. When the locking projection 12z is removed from the tip of the passage groove 49, the knob 46 is hooked on a finger and the support tube 41B is rotated, whereby the locking projection 12z is rotated.
And the locking of the step 45 is obtained. In this state, the holder 160 and the objective unit 40B are urged forward by the force of the compressed coil spring 88, and moreover,
Since the objective unit 40B is prohibited from moving forward, the holder 160 and the objective unit 40B are stably supported. Even when the objective unit 40B is removed, the locking projection 12z is passed through the passage groove 49. Also in this embodiment, it is possible to replace the objective unit 40B with another objective unit, for example, a wide-angle objective unit.

In this embodiment, focusing is performed as follows. By slightly pushing in the objective unit 40B, the engagement state between the locking convex portion 12z and the engaging concave portion 45a is released. As a result, the objective unit 40B becomes rotatable. Next, the knob unit 46a is caught by a finger and the objective unit 40B is rotated. As a result, the contact position of the follower pin 92 with respect to the inclined cam surface 91 changes, and the holder 1
60 is axially aligned. This adjustment position is stably maintained by the engagement protrusion 12z engaging with one of the engagement recesses 45a.

The present invention is not limited to the embodiments described above, and various modes are possible. For example, the adjusting member for focusing may be rotated by a motor provided inside or outside the body. The fourth embodiment can also be applied to an endoscope having a flexible insertion portion. In this case, only the tip part of the insertion part is rigid. In all embodiments, the objective unit need not be replaceable. The image transmitting means may be an optical fiber bundle, and in this case, the tip end surface of the optical fiber bundle serves as the light receiving means. The base portion may be provided with an eyepiece portion so that the image sent from the optical fiber bundle can be seen.

[0058]

As described above, according to the first aspect of the present invention, the holder can be axially adjusted in position by rotating the adjusting member, whereby the positions of the light receiving means and the objective optical system can be adjusted. The relationship can be adjusted or focused. Moreover, since screwing between the adjusting member and the holder is used, it is possible to perform focusing with high accuracy.
Further, since the light receiving means does not rotate during this focusing, the positional relationship in the vertical and horizontal directions of the visual field does not change, and there is no hindrance to observation. According to the invention of claim 2, since the image transmission means passes through the tubular holder and the adjusting member, the internal space of the insertion portion can be effectively utilized and the insertion portion can be made thin. According to the invention of claim 3, the holder and the adjusting member can be securely held via the guide tube. According to the invention of claim 4, the means for locking the holder so as not to be rotatable and movable in the axial direction can have a simple structure.
According to the fifth and sixth aspects of the invention, the means for locking the adjusting member so as to be rotatable and immovable in the axial direction can have a relatively simple structure. According to the invention of claim 7, focusing can be performed by a simple rotation operation at the rear end portion of the adjusting member. According to the invention of claim 8, focusing can be performed by a simple rotation operation at the rear end portion of the operation member. According to the invention of claim 9, the objective optical system can be exchanged, and the focus can be adjusted after the exchange. According to the invention of claim 10, the position of the holder can be adjusted and the focus can be adjusted through the cam means by the turning operation of the support tube. Since the adjusting member for adjusting the position is unnecessary, the structure is simple. According to the invention of claim 11, it is possible to regulate the rotation of the support tube and reliably maintain the holder at the adjusted position by the simple configuration of the locking convex portion and the engaging concave portion. Claim 12
According to the invention, the objective optical system can be exchanged, and the focus can be adjusted after the exchange.

[Brief description of the drawings]

FIG. 1A is a vertical sectional view of an endoscope which constitutes a first embodiment of the present invention. (B) is a longitudinal sectional view showing a different objective unit that can be mounted in the same embodiment.

FIG. 2 is a vertical sectional view of an endoscope which constitutes a second embodiment of the present invention.

FIG. 3 is a vertical sectional view of an endoscope which constitutes a third embodiment of the present invention.

FIG. 4 is a vertical cross-sectional view showing a structure of a distal end portion of an endoscope which constitutes a fourth embodiment of the present invention.

FIG. 5 is a plan view showing a partial cross-section of the distal end structure of the endoscope of the fourth embodiment.

FIG. 6 is a front view of the structure of the distal end portion of the endoscope according to the fourth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Body 5 ... Position adjustment means 10 ... Insertion part 12 ... Inner tube (guide tube) 12y ... Key (2nd locking means) 12z ... Locking convex part (1st locking means, maintenance means) 30 ... Optical fiber Bundle (illumination light transmitting means) 41, 41A, 41B ... Support tubes 42, 42A ... Objective optical system 45 ... Stage (first locking means) 45a ... Engagement recess (maintaining means) 46 ... Knob (operating section) 50 ... guide tube 52 ... accommodation hole (first locking means) 53 ... pin (second locking means) 56 ... spring (second locking means) 60 ... holder 61 ... head part (first locking means) 65 ... Image sensor (light receiving means) 66 ... Signal line (image transmitting means) 70 ... Adjusting member 71 ... Knob portion (rotating operation portion) 72 ... Annular groove (second locking means) 88 ... Spring 150 ... Guide tube 161 ... Key groove Second locking means) 171 ... adjusting member 172 ... operating member 171x ... engagement flange (convex portion, second locking means) 172 b ... knob portion (pivot operation part) 172c ... annular groove (second engaging means)

Claims (12)

[Claims] 1. An illumination light transmission means having: (a) a body having a long hollow hard insertion portion, and (b) a tip portion disposed inside the tip portion of the insertion portion and extending rearward through the insertion portion. And (c) an objective optical system arranged in the distal end portion of the insertion portion, and (d) a light receiving unit arranged behind the objective optical system and receiving reflected light from an observation target through the objective optical system,
(E) An image transmitting means for sending the image information received by the light receiving means to the rear through the insertion part, (f) a holder for holding the light receiving means, and (g) the holder for the objective optical system. And a position adjusting means for adjusting the position in the axial direction by means of the first adjusting means, wherein the position adjusting means locks the holder axially movable with respect to the insertion portion and non-rotatably locked. Stopping means, an adjusting member that extends in the axial direction of the insertion portion and has a tip portion screwed into the rear end portion of the holder, and the adjusting member is rotatable with respect to the body and is immovably locked in the axial direction. An endoscope having a second locking means, wherein the position of the holder is axially adjusted in accordance with the rotation of the adjusting member. 2. The endoscope according to claim 1, wherein the holder and the adjusting member have a tubular shape, and the image transmitting means is inserted into the inside of the holder and the adjusting member. 3. The insertion portion includes a guide tube extending in the axial direction, the holder and the adjusting member are housed in the guide tube, and the guide tube is locked to the guide tube by the first and second locking means. The endoscope according to claim 1 or 2, wherein 4. The first locking means comprises a housing hole having a non-circular cross section formed at the tip of the guide tube, and a head part of the holder having a non-circular cross section housed in the housing hole. The endoscope according to claim 3, wherein: 5. The second locking means comprises an annular groove formed on the outer periphery of the adjusting member and a pin provided on the guide tube and inserted into the annular groove. The endoscope according to Item 3. 6. The second locking means comprises a spring for urging the holder forward and a convex portion provided on the adjusting member and abutting on the rear end of the guide tube. The endoscope according to Item 3. 7. The endoscope according to claim 3, wherein a rear end portion of the adjusting member is provided as a rotating operation portion by protruding to the outside. 8. An operating member which is rotatably inserted into the rear end portion of the guide tube so as not to move in the axial direction, and the rear end portion of the operating member is provided outside as a rotating operation portion. , The front end of the operating member and the rear end of the adjusting member are
The endoscope according to claim 3, wherein the endoscope is connected so as to be movable in the relative axial direction and not relatively rotatable. 9. The objective optical system is supported in a support tube, the support tube is detachably accommodated in an insertion section, and the guide tube is accommodated in the insertion section so as to be slidable in an axial direction. The endoscope according to claim 3, wherein an end portion is detachably connected to a tip portion of the guide tube. 10. An endoscope comprising the constituent elements (a) to (g) according to claim 1, wherein the objective optical system is supported in a support tube as a constituent element of the position adjusting means,
The position adjusting means further includes first locking means for allowing the support tube to rotate and locking the tip of the support tube to prohibit forward movement, and the holder in the axial direction with respect to the insertion portion. A second locking means that is movable and non-rotatably locked, a spring that biases the holder toward the support tube, and a rear end of the support tube and a tip of the holder cooperate to rotate the support tube. An endoscope comprising: cam means for axially adjusting the position of the holder according to movement. 11. The first locking means includes a locking projection that is provided in the insertion portion and projects in the radial and inward directions, and the tip of the support tube is locked to the locking projection. The forward movement of the support pipe is prohibited, and a plurality of engagement recesses are formed along the circumferential direction at the tip of the support pipe, and one of these engagement recesses is the locking projection. The endoscope according to claim 10, wherein the pivotal position of the support tube is maintained by the engagement. 12. A support groove extending in the axial direction is formed on the outer periphery of the support tube, and the support groove is formed when the support groove is inserted into or removed from the tip of the insertion section of the support tube. The endoscope according to claim 11, wherein the endoscope is used for passing an endoscope.