JP2001258823A - Endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endoscope in which an illuminating optical system can be arranged as compact as possible, and the balance of illuminating light distribution is improved. SOLUTION: In this endoscope, an observation window 29 is arranged closer to one side from the central position of an insert part 3 at the tip of the insert part 3. The straight line passing the center of the insert part 3 and the center of the observation window 29 is set to a first axis A, and the straight line vertical to the first axis A and passing the center of the observation window 29 is set to second axis B. When the area of the tip surface of the insert part 3 is halved by the second axis B, the area part on the side not containing the center of the insert part is set to a first surface part 26, and the area part of the side containing the center of the insert part is set to a second surface part 27. The illuminating light transmitting performance of the light guide fiber of the illuminating optical system where an illuminating window is arranged on the first surface part 26 is set smaller than the illuminating light transmitting performance or the light guide fiber of the illuminating optical system where the illuminating window is arrange on the second surface part 27.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope provided with an observation optical system and an illumination optical system, wherein an observation window of the observation optical system and an illumination window of the illumination optical system are arranged at the tip of an insertion portion. About.

[0002]

2. Description of the Related Art In general, an endoscope is provided with an observation optical system and an illumination optical system, and the observation window and the illumination window are located at an insertion portion by avoiding a position where another forceps channel opening or a jet nozzle is installed. It is located at the tip. A light guide fiber bundle in which a number of optical fiber (optical fiber) elements are bundled is used as illumination light transmission means of the illumination optical system. Illumination light sent from the endoscope light source device to the illumination optical system via the light guide fiber bundle is emitted from the illumination optical system toward an observation region in the body cavity. At the tip of the endoscope, an observation window of an observation optical system, an illumination window of an illumination optical system, a forceps channel opening, an injection nozzle, and the like are arranged so as not to interfere with each other.

As shown in Japanese Patent Laid-Open Publication No. Hei 6-31960, a layout at the tip of an endoscope includes an observation window of one observation optical system and an illumination window of two illumination optical systems.
Some forceps channels are arranged so as to avoid the positions where the tip openings of the forceps channels and the ejection nozzles are arranged.

[0004]

In the case of the above-mentioned conventional endoscope, the center of the observation window of the observation optical system is located at a position shifted to one side from the center of the insertion portion of the endoscope. Then, the straight line passing through the center of the insertion portion of the endoscope and the center of the observation window of the observation optical system and being straight through the center of the observation window of the observation optical system divides the distal end surface area of the endoscope into two parts. The illumination windows of the two illumination optical systems are arranged in a range including the center of the insertion portion, and both illumination windows are arranged at positions deviated from the observation window of the observation optical system. For this reason, the balance of the illumination light distribution is poor.

(Object) The present invention has been made in view of the above problems, and an object of the present invention is to provide an endoscope in which an illumination optical system can be arranged as compactly as possible and an illumination light distribution balance is improved. Is to provide.

[0006]

SUMMARY OF THE INVENTION The present invention provides an observation optical system for observing the inside of a field of view at an end of an insertion portion, and an illumination optical system for emitting illumination light transmitted by a light guide fiber into the field of view. System, the illumination optical system includes two or more illumination optical systems, and an endoscope provided with an observation window of the observation optical system and an illumination window of two or more illumination optical systems at the tip of the insertion portion. The observation window is arranged at the tip of the insertion portion so as to be deviated to one side from the center position of the insertion portion, and a straight line passing through the center of the insertion portion and the center of the observation window is defined as a first axis, and observation is performed perpendicular to the first axis. A straight line passing through the center of the window is defined as a second axis,
When the region of the distal end surface of the insertion portion is bisected by the axis of the above, the region portion not including the center of the insertion portion is defined as a first surface portion, and the region portion including the center of the insertion portion is defined as a second surface portion. The light transmission capability of the light guide fiber of the illumination optical system in which the illumination window is disposed on the first surface, and the light guide fiber of the illumination optical system in which the illumination window is disposed on the second surface. Is smaller than the illuminating light transmission capacity of the above.

For example, the total cross-sectional area of the light guide fiber bundle of the illumination optical system in which the illumination window is disposed on the first surface portion is determined by the illumination optical system in which the illumination window is disposed on the second surface portion. Or the total number of light guide fibers of the light guide fiber bundle of the illumination optical system provided on the first surface is smaller than the total cross-sectional area of the light guide fiber bundle of the light guide fiber bundle provided on the second surface. The number of the light guide fibers in the bundle of light guide fibers of the illumination optical system which has been set is smaller than the total number of light guide fibers.

[0008] The light guide fiber of the illumination optical system in which the illumination window is disposed in the range including the center of the insertion portion has a large illumination light transmission capability, and the irradiation amount in this direction is large. However, the observation optical system is shifted to the opposite side by that amount, and is away from the observation target, for example, the intestinal wall, so that the illumination light reaching the observation target has an appropriate light amount. On the other hand, the illumination light transmission capacity of the light guide fiber of the illumination optical system arranged in a range not including the center of the insertion portion is small, so that the irradiation amount in this direction is small. However, since the observation optical system has shifted to the observation target side and is approaching the observation target, for example, the intestinal wall,
The illumination light reaching the observation target has an appropriate light amount. Therefore, the light distribution is well balanced.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] FIGS. 1 to 13
The endoscope system according to the first embodiment of the present invention will be described with reference to FIG.

(Configuration) FIG. 1 is an explanatory view schematically showing an endoscope system according to a first embodiment of the present invention. FIG.
As shown in the figure, the endoscope 1 is divided into an operation unit 2 for performing a bending operation and a control of a duct system, an insertion unit 3 for insertion into a body cavity, and a connector unit 4 with a cord. 5 and a video processor 6. The video processor 6 is connected to a monitor 7. The insertion portion 3 has a flexible tube 8 and a curved portion 9 provided on the distal end side thereof, and a distal end portion 10 is provided at the most distal end.

As shown in FIGS. 3 and 4, the distal end portion 10 of the endoscope 1 has a distal end hard member 11, and the outer periphery of the distal end portion of the distal end hard member 11 is made of an electrically insulating material. It is covered with a tip cover 12. The distal end cover 12 is fitted and fixed to the distal end hard portion 11. The bending portion 9 of the insertion portion 3 is connected to the rear end of the tip portion 10. The bending portion 9 is configured by covering a bending tube 15 formed by connecting a number of node rings 14 with a resin tube 16. The bending section 9 is configured to bend to the pulling side by pushing and pulling four operation wires 17 arranged vertically and horizontally in the insertion section 3 by operating the operation section 2.

As shown in FIG. 3, a distal end portion 10 of the endoscope 1 is provided.
Is provided with one observation optical system (objective optical system) 21.
The center P1 of the observation optical system 21 is set at the distal end 10 of the insertion section 3.
Are arranged to be shifted (shifted) from the center P2. Around the observation optical system 21, a plurality of illumination optical systems 22a, 22b, 23a, 23b, a channel opening 18, and an air / water supply nozzle 19 are arranged in a substantially annular shape.

As shown in FIG. 2, the observation optical system 21
A straight line passing through the center P1 of the optical axis and the center P2 of the distal end portion (insertion portion 3) 10 is defined as a first axis A. A straight line that is perpendicular to the first axis A and passes through the center P1 of the observation optical system 21 is Second
When the distal end face of the distal end portion 10 is bisected by the second axis B, the insertion portion 3, that is, the upper region portion not including the center P <b> 2 of the insertion portion 3 is defined as the first surface portion 26, and The lower area portion including the center P2 of the portion 3 is
And

In this case, two illumination optical systems 22a and 22b are arranged in the first surface portion 26, and two other illumination optical systems 23a and 23b are arranged in the second surface portion 27. The two illumination optical systems 22a and 22b arranged in the first surface portion 26 are arranged symmetrically with respect to the first axis A, and the two illumination optical systems arranged in the second surface portion 27. The systems 23a and 23b are also arranged symmetrically with respect to the first axis A. The channel opening 18 and the air / water supply nozzle 19 are also arranged in the second surface 27 so as to be located substantially symmetrically to the left and right with respect to the first axis A.

The illumination optical systems 22a, 22b, 23
The positions at which the illumination optical systems 22a, 23b are arranged
It is the central optical axis of 22b, 23a, 23b, and also the position where the center of the cross section of the light guide fiber bundle described later is arranged.

The sum of the illumination light transmission capabilities of the light guides of the two illumination optical systems 22a and 22b disposed in the first surface portion 26 is equal to the other two illumination optical systems disposed in the second surface portion 27. The sum of the illuminating light transmission capabilities of the light guides 23a and 23b is small.

Here, the illumination light transmission capability of the light guides for the two illumination optical systems 22a and 22b disposed in the first surface portion 26 is the same, and is disposed in the second surface portion 27. Two illumination optical systems 23a and 23b
The same applies to the illumination light transmission capability of the light guide for

Next, the specific contents of the observation optical system 21 will be described. As shown in FIG. 4, the observation optical system 21 includes an imaging lens group 25 and a solid-state imaging device 33,
The endoscope observation field is formed on the solid-state imaging device 33 by the imaging lens group 25. The imaging lens group 25 forms an objective optical system.

As shown in FIG. 10, the imaging lens group 25 includes a lens group 25a incorporated in a lens barrel 34,
A lens group 25b is attached to the tip of the through-hole 28 into which the lens barrel 34 is fitted. The lens group 25a and the lens group 25b are coaxially arranged on the observation optical axis L.

The forefront lens in the imaging lens group 25 constitutes a window member 30 of an observation window 29 exposed on the distal end surface of the distal end portion 10. The optical axes of the imaging lens group 25 and the observation window 29 may be bent by a prism or a mirror, but the optical axis L of the observation optical system 21 is a straight line passing through the center P1 of the observation optical system 21 described above. Match above.

The lens group 25 enables wide-angle observation exceeding 180 °. For this reason, as shown in FIG. 5, the front surface of the distal end cover 12 has a substantially conical shape so that the field of view is not lost, and when combined with the distal end surface portion of the lens group 25, the distal end surface of the distal end portion 10 becomes bullet-shaped. It is formed in a shape that can be seen.

The center P1 of the observation optical system 21 is located at the insertion center P2.
4, the apex of the conical shape of the distal end cover 12 is shifted upward, so that the lower side becomes longer in the front-rear direction, and the distal end 10 is cut within the range of the distance U shown in FIG. The area will change. For this reason, the change in the cross-sectional area of the distal end portion 10 becomes gentle, and the insertability of the insertion portion 3 is improved.

The solid-state imaging device 33 is incorporated in the imaging lens barrel 31 as shown in FIG. The imaging lens barrel 31 is connected to the lens barrel 34 so as to be fitted around the rear end of the lens barrel 34. The solid-state imaging device 3 is provided in the imaging lens barrel 31.
In addition to 3, a not-shown substrate, an IC chip, and the like are built in, and the CCD unit 32 is configured by this.

On the other hand, the channel opening 18 extends over both the operation section 2 and the insertion section 3 and is connected to a channel (not shown) provided therein. The channel is used for inserting and aspirating a treatment instrument therethrough.

As shown in FIG. 4, the air / water nozzle 1
A protection member 36 made of an electrically insulating material is fitted around the outer periphery of the wire 9, and is bonded and fixed to the distal end hard member 11 of the distal end portion 10 via the protection member 36. Since the air / water nozzle 19 is attached via the protection member 36 in this manner, it is electrically disconnected from the endoscope main body.

The nozzle hole 3 of the air / water supply nozzle 19
Numeral 7 is formed into a narrow taper shape at the tip end by electric discharge machining. The foremost opening (mouth) 38 in the nozzle hole 37 of the air / water supply nozzle 19 is formed substantially orthogonal to the nozzle hole 37 toward the outer surface 39 of the observation window 29.

As shown in FIG. 5, each illumination optical system 22a,
Each of 22b, 23a, and 23b has an illumination lens 41 constituting an illumination window 40 exposed on the distal end surface of the distal end portion 10, and the illumination lens 41 is held by a lens frame 42.

Each illumination optical system 22a, 22b, 23a, 2
The center optical axis of 3b is 30 degrees with respect to the optical axis L of the observation optical system 21.
The lens is arranged to be inclined outward at an angle of
Corresponding to a wide-angle field of view. Each illumination optical system 22a,
At the rear ends of the illumination lenses 41 of 22b, 23a and 23b, the front end portions of light guide fiber bundles (light guides) 45 and 46 are coaxially arranged.

That is, the light guide fiber bundles 45 and 4
6 is disposed so as to be inclined outward at an angle of 30 ° with respect to the center P1 of the observation optical system 21.

Each of the light guide fiber bundles 45 and 46 is formed by bundling a predetermined number of optical fibers (fibers), and formed at the distal ends of the light guide fiber bundles 45 and 46 by a first fixing base 44. . First fixing base 4
Reference numeral 4 is attached so that the leading end of the molded portion 47 of the light guide fiber bundles 45 and 46 does not enter the concave portion 48 provided at the rear end of the illumination lens 41.

As shown in FIG. 5, upper and lower sets of illumination optical systems 22a and 23a (or 22b,
23b) a pair of light guide fiber bundles 4 connected to
The molded portions 47 of the reference numerals 5 and 46 are guided backward while curving through an oblong hole 56 described later in the distal end portion 10, and are parallel to the optical axis L of the observation optical system 21, as shown in FIG. Is guided to the base end side of the insertion portion 3 via a second fixing base 49 attached to the distal end hard member 11.

As shown in FIG. 7, the pair of light guide fiber bundles 45 and 46 are formed so as to merge at the rear. Each of the light guide fiber bundles 45 and 46 is formed so that the base end side portion thereof is soft from the second fixing base 49, and the portion up to the merging is covered with the silicone tube 51. The light guide fiber bundle 52 after the merging is covered with another silicone tube 53 including the rear end portion of the silicone tube 51. In other words, the silicone tube 51 is interrupted in the middle and disappears, and is covered with another silicone tube 53 alone. A protective tube 54 covers the outer periphery of the silicone tube 53.

Until the upper light guide fiber bundle 45 and the lower light guide fiber bundle 46 merge, the upper part of the protective tube 54 is cut away, and the distal end side of the cutaway remaining protective tube 54 is cut off. The lower light guide fiber bundle 46 is placed on the portion, and the protection tube 5
4 is bound and fixed to the second fixing base 49. FIG. 8 shows a connection state of the silicone tubes 51 and 53 and the protection tube 54 at a portion where the light guide fiber bundles 45 and 46 join.

As shown in FIG. 6, the second fixing base 49 has an oval hole 5 formed in the distal end hard portion 11 of the distal end member 10.
6 and is positioned in a state of being pressed against one end of the long axis of the oblong shape, and is fastened and fixed by a screw 57 at that position. A screw hole 58 into which the screw 57 is fitted opens in the outer periphery of the distal end hard member 11.
An empty portion of the screw hole 58 left by screwing the screw 57 is filled with a filler 59.

FIG. 9 shows a modification of the means for fixing the light guide fiber bundles 45 and 46 to the distal end hard member 11 of the distal end portion 10. As shown in FIG. In this means, at least a part of the light guide fiber bundles 45 and 46 is formed in a columnar shape, the portion of the columnar portion 61 and the block 62 are fitted into a U-shaped base 63, and the base 63 is screwed with a screw 64. Tighten and fix. Since the length of the block 62 is smaller than the diameter of the column 61 of the light guide fiber bundles 45 and 46, the U-shaped base 63 is deformed by tightening the screw 64, and the column 61 is firmly fixed. . The initial state of the U-shaped base 63 is as shown in FIG. 9B, but FIG. 9A shows the light guide fiber bundles 45 and 4.
6 is assembled. When the screw 64 tightens the U-shaped base 63 with the block 62, the deformation of the U-shaped base 63 is limited, and a force greater than a predetermined tightening force is not applied to the column portion 61. Thus, the light guide fiber bundles 45 and 46 are not broken. The portions of the light guide fiber bundles 45 and 46 which are tightened and fixed in this manner may be provided with the fixing base 49 as shown in FIG. 6 or FIG. 7, or may be without the fixing base 49 as shown in FIG. In this modification, even if the fixing base 49 is not provided, even if the screw 64 is excessively tightened, the light guide fiber bundles 45 and 46 can be attached and fixed without breaking.

The light guide fiber bundle 45 connected to the upper illumination optical system 22a (22b) is thin, and the number of optical fibers is small. On the other hand, the lower illumination optical system 23a
The light guide fiber bundle 46 connected to (23b) is thick, and the number of optical fibers is large. In other words, the upper light guide fiber bundle 45 constitutes a light guide having a small (small) illumination light transmission capability, and the lower light guide fiber bundle 46.
Constitutes a light guide having a large (large) light transmission capability.

The observation optical system 21 of the present embodiment has a configuration in which the magnification and the angle of view can be changed. FIG. 10 shows the configuration in detail. That is, as described above, the observation optical system 21 is roughly divided into the imaging lens group 25 and the CCD unit 32.

The imaging lens group 25 is divided into an objective lens unit 71 having a lens group 25b located on the front end side, and a variator lens unit 72 disposed behind the objective lens unit 71.

The variator lens unit 72 is slidably fitted in the cylinder 74 of the lens / cylinder unit 73. The variator lens unit 72 includes a movable lens 76 provided on a cylindrical sliding lens frame 75.

On the side surface of the sliding lens frame 75, there is formed a projection 77 projecting downward from the cylinder 74 in a lever shape. The protrusion 77 penetrates a notch 78 formed in the lens / cylinder unit 73 along the movement axis direction of the sliding lens frame 75. A large projection 79 larger than the projection 77 is formed on the cylinder 74 at the rear side of the notch 78.

A wire unit 81 for moving the variator lens unit 72 back and forth is connected to the protrusion 77. The wire unit 81 includes a stopper 82 and a wire 83, and the stopper 82 is fixed by being brazed at the tip of the wire 83.

The large protrusion 79 has a pipe unit 85.
Is screwed. The pipe unit 85 includes a tubular abutting member 86 and a pipe member 87.
7 is fixed to the abutment member 86 by bonding or soldering. The wire 83 is inserted through the pipe unit 85. The abutting member 86 is formed with a screw portion 88 on the outer periphery, and the abutting member 86 is screwed into the large projecting portion 79 so that the front and rear positions can be adjusted and selected.

Then, by moving the wire unit 81 back and forth by manual operation on the operation unit 2 of the endoscope 1 or by electric drive using a motor (not shown), the front and rear positions of the variator lens unit 72 are selected and observed. The magnification and the angle of view of the optical system 21 can be changed. According to this configuration, by rotating the pipe unit 85, it is easy to adjust the magnification and the angle of view of the observation optical system 21.

FIG. 11 shows a change in the angle of view of the observation optical system 21. The aforementioned variator lens unit 72
Moves to the most distal end side, and the protrusion 7 is formed at the edge of the notch 78.
When 7 strikes, a viewing angle of 140 ° that allows normal observation is ensured. Also, the variator lens unit 72
Moves to the most proximal side and the projection 77 abuts against the abutting member 86, and the angle of view becomes 210 degrees, which enables observation in the side direction.

Accordingly, both the direct viewing direction and the side viewing direction can be observed only by inserting the endoscope 1 into the body once, which is different from the case where the direct viewing endoscope and the side viewing endoscope are separately inserted. Can also reduce the burden on the patient. Also, one observation optical system 21
Can perform direct and side-view observations with a single endoscope, making it possible to make the diameter smaller than that of a model that has both a direct-view observation optical system and a side-view observation optical system in one endoscope, and with less invasion to the patient A mirror 1 can be provided.

Further, it is possible to observe the side surface in all directions of 360 ° at a viewing angle exceeding a viewing angle of 180 ° or more, and it is possible to reduce oversight of a lesion. Furthermore, since observation can be performed at a viewing angle of 180 ° or more, it is possible to observe a portion of the intestinal fold that has been shadowed at a normal viewing angle, which is highly medically useful.

(Operation) FIG. 2 shows a state where the distal end portion 10 is viewed from the front side when the insertion portion 3 of the endoscope 1 is inserted into the large intestine (intestinal tract) 90. At the time of endoscopy of the large intestine 90, it is easier to uniformly observe the entire body if the center of the insertion section 3 is located closer to the center of the large intestine 90 in order to discover the presence or absence of a lesion. In an average use situation, the center of the insertion section 3 of the endoscope 1 tends to be arranged at the center of the large intestine 90.

However, in the case of the endoscope 1, the observation optical system 2
1 is the center P2 of the distal end portion 10 in the insertion portion 3.
, The distance between the intestinal wall and the observation optical system 21 in the shifted direction becomes relatively short. As the distance is shorter, less illumination light is required. The distance between the intestinal wall and the observation optical system 21 in the direction opposite to the direction shifted in the opposite direction is relatively long. The longer the distance, the more the illumination light needs to be.

In this embodiment, the number of light guide fibers of the two illumination optical systems 22a and 22b in the direction in which the observation optical system 21 is shifted, that is, the two illumination optical systems 22a and 22b within the range of the first surface portion 26 is small. Since the number of light guide fibers of the two illumination optical systems 23a and 23b in the direction opposite to the direction in which is shifted, that is, within the range of the second surface portion 27, is large, the overall light distribution is good.

The two illumination optical systems 22a and 22b in the range of the first surface 26 are bilaterally symmetric with respect to the straight line A, and similarly, the two illumination optical systems in the range of the second surface 27. Since the systems 23a and 23b are symmetrical with respect to the straight line A, the left and right light distribution with respect to the straight line A is well balanced.

Since the center P1 of the observation optical system 21 is shifted with respect to the center P2 of the insertion section 3, a space margin can be created in the direction opposite to the direction in which the observation optical system 21 is shifted. . Since the channel opening 18 and the air / water supply nozzle 19 can be laid out in the extra space, the dead space can be reduced in layout, and as a result, the outer diameter of the insertion section 3 of the endoscope 1 can be reduced.
The secondary effect that the insertability can be improved is obtained.

In this embodiment, the means for changing the viewing angle by the optical zoom has been described. However, the endoscope of the present invention may have the structure of the means for changing the visual field by the electronic zoom as follows. .

FIG. 12 shows a state in which a light beam hits the solid-state image pickup device 33 at a viewing angle of 210 °. A range 93 where the light beam hits and a range 94 where the light beam does not hit.
Are both shown.

FIG. 13 shows that, as described above, the area 93 to which the light beam hits is further moved to 140 by an electronic mask.
This shows a state where the viewing angle is narrowed down to °. Reference numeral 95 denotes a range where the electronic mask is acted. Even when an electronic mask is applied, the image appears to have been enlarged by enlarging it to the same screen size as at 210 ° with the electronic zoom.

When the angle of view is switched by the electronic zoom as described above, the size of the lens group can be made smaller than that of the lens group of the optical zoom. Invasion can be reduced.

[Second Embodiment] FIG. 14 is a front view of a distal end portion 10 of an endoscope 1 according to a second embodiment of the present invention. This embodiment is an example in which the center P1 of the observation optical system 21 is shifted not obliquely but directly above the center P2 of the distal end portion 10.

Also, one small illumination optical system 22, one large illumination optical system 23, the channel opening 18, and the air / water nozzle 19 are arranged around the observation optical system 21 in a substantially annular shape. .

As in the case of the first embodiment described above, the illumination light transmission capability of the light guide belonging to the small illumination optical system 22 is small, and the illumination light transmission capability of the light guide belonging to the large illumination optical system 23 is increased. It is configured. The illuminating light transmission ability is obtained by a difference in the total number of fibers of the light guide or the like.

As shown in FIG. 14, a straight line passing through the center P1 of the observation optical system 21 and the center P2 of the distal end portion 10 is defined as a first axis A, and is perpendicular to the first axis A, and is perpendicular to the first axis A.
A straight line passing through the center P1 of the first part is defined as a second axis B, and when the tip surface of the tip part 10 is bisected by the second axis B, the insertion part 3,
In other words, the region on the side not including the center P2 of the distal end portion 10 is defined as the first surface portion 26, and the region on the side including the center P2 of the distal end portion 10 is defined as the second surface portion 27.

In this case, the center of the small illumination optical system 22 is located within the area of the first surface portion 26 and on the first axis A. The center of the large illumination optical system 23 is located in the area of the first surface 26 and on the first axis A.

The channel opening 18 and the air / water supply nozzle 19 are located within the area of the second surface 27 and are arranged substantially symmetrically to the left and right of the first axis A. The air supply / water supply nozzle 19 is positioned obliquely above the observation optical system 21, the opening is directed to the observation optical system 21, and the channel opening 18 is provided below the observation optical system 21.

The light transmission capability (for example, the total number of fibers) of the light guide of the small illumination optical system 22 is smaller than the illumination light transmission capability (for example, the total number of fibers) of the large illumination optical system 23. Therefore, as in the case of the above embodiment, the overall light distribution is good.

[Third Embodiment] FIG. 15 is a front view of a distal end portion 10 of an endoscope 1 according to a third embodiment of the present invention. In the present embodiment, the small illumination optical systems 22a, 22b, 22c and the air / water nozzles 19 having the same size are within a range corresponding to the range of the first surface portion 26 described in the first embodiment.
Are provided, and large illumination optical systems 23a and 23b and channel openings 18 of the same size are provided in a range corresponding to the range of the second surface portion 27. These are arranged substantially annularly around the observation optical system 21.

The illumination window of the small illumination optical system 22b in the middle is located on the first axis A, and the other illumination optical systems 22b
The illumination windows a and 22c are symmetrically arranged on the left and right of the first axis A. Also, large illumination optical systems 23a and 23b
Are also symmetrically arranged on the left and right of the first axis A. The channel opening 18 is located on the first axis A and is located immediately below the observation window of the observation optical system 21. Further, the air / water supply nozzle 19 is located on or near the straight line B.

Small illumination optical systems 22a, 22b, 22c
Have the same illumination light transmitting ability, for example, the number of fibers in each light guide is the same. In addition, the illumination light transmission capabilities of the respective light guides of the large illumination optical systems 23a and 23b are equal, and for example, the number of fibers of each light guide is the same.

Further, three small illumination optical systems 22a,
The sum of the illumination light transmission capacities of the light guides 22b and 22c (for example, the total number of fibers) is smaller than the sum of the illumination light transmission capacities of the two large illumination optical systems 23a and 23b (for example, the total number of fibers). Therefore, as in the case of the above embodiment, the overall light distribution is good.

The present invention is not limited to the above embodiments. According to the above description, the terms of each group listed in the following supplementary notes and those obtained by arbitrarily combining the terms are obtained.

[Supplementary Notes] <First Group> (1) At the tip of the insertion portion, an observation optical system for observing the inside of the field of view, and two or more that emit illumination light transmitted by the light guide fiber into the field of view. In an endoscope in which the observation window of the observation optical system and the illumination window of two or more illumination optical systems are provided at the distal end of the insertion portion, the center of the insertion portion is positioned at the distal end of the insertion portion. The observation window of the observation optical system is arranged so as to be deviated to one side from the position, and a straight line passing through the center of the insertion portion and the center of the observation window is defined as a first axis, and a straight line perpendicular to the first axis and passing through the center of the observation window. Is defined as a second axis, and when the region of the distal end surface of the insertion portion is bisected by the second axis, the region on the side not including the center of the insertion portion is defined as the first surface portion and includes the center of the insertion portion. The area on the side is referred to as a second surface,
The illumination light transmission capacity of the light guide of the illumination optical system in which the illumination window is disposed on the second surface is the illumination light transmission capacity of the light guide of the illumination optical system in which the illumination window is disposed on the second surface. An endoscope characterized by being configured smaller than the endoscope.

(2) An observation optical system for observing the inside of the field of view and an illumination optical system for emitting the illumination light transmitted by the bundle of light guide fibers into the field of view are provided at the distal end of the insertion section. Is provided with two or more components, and an endoscope provided with an observation window of the observation optical system and an illumination window of two or more illumination optical systems at the distal end of the insertion portion. Is shifted from the center of the observation window, a straight line passing through the center of the insertion portion and the center of the observation window is defined as a first axis, and a straight line perpendicular to the first axis and passing through the center of the observation window is defined as a second axis. When the region of the distal end surface of the insertion portion is bisected by the second axis, the region portion not including the center of the insertion portion is defined as the first surface portion and the region portion including the center of the insertion portion. A second surface portion, an illumination optical system having an illumination window disposed on the first surface portion, and a second surface portion. And an illumination optical system in which an illumination window is disposed in the first surface portion, and the total cross-sectional area of the light guide fiber bundle of the illumination optical system in which the illumination window is disposed in the first surface portion is in the second surface portion. An endoscope characterized in that the endoscope is configured to be smaller than a total cross-sectional area of a light guide fiber bundle of an illumination optical system in which an illumination window is provided.

(3) An observation optical system for observing the inside of the field of view and an illumination optical system for emitting the illumination light transmitted by the light guide fiber bundle into the field of view are provided at the distal end of the insertion section. Is provided with two or more components, and an endoscope provided with an observation window of the observation optical system and an illumination window of two or more illumination optical systems at the distal end of the insertion portion. Is shifted from the center of the observation window, a straight line passing through the center of the insertion portion and the center of the observation window is defined as a first axis, and a straight line perpendicular to the first axis and passing through the center of the observation window is defined as a second axis. When the region of the distal end surface of the insertion portion is bisected by the second axis, the region portion not including the center of the insertion portion is defined as the first surface portion and the region portion including the center of the insertion portion. A second surface portion, an illumination optical system having an illumination window disposed on the first surface portion, and a second surface portion. And an illumination optical system in which an illumination window is disposed in the first portion. The total number of light guide fibers of the light guide fiber bundle of the illumination optical system in which the illumination window is disposed in the first surface portion is the second. An endoscope wherein the number of light guide fibers of the light guide fiber bundle of the illumination optical system in which the illumination window is disposed on the surface of the light guide fiber is smaller than the total number of light guide fibers.

(4) The respective light guide fiber bundles are arranged so that the illumination window of the illumination optical system is symmetrical in the area on both sides of the first axis. 3. The endoscope according to 3.

(5) The endoscope according to any one of items 1, 2, and 3, wherein an opening at the end of the channel and an air / water nozzle are arranged within the range of the second surface.

(6) The center of the observation window of the observation optical system is shifted with respect to the center of the insertion portion, and a conical or shell-shaped shape is formed with the front surface of the observation window of the observation optical system as the apex. The endoscope according to any one of Items 1, 2, 3, 4, and 5, wherein the distal end of the insertion portion is formed in a shape having a predetermined shape.

(7) The endoscope according to any one of Items 1, 2, 3, 4, 5, and 7, wherein the observation optical system has a viewing angle of 180 ° or more.

The position where the illumination window, the light guide fiber bundle, the opening at the tip of the channel or the air / water supply nozzle is located is the position where the center of each cross section is located.

<Second Group> (1) Having one observation optical system, the observation optical system can be switched from a field of view having a viewing angle of 180 ° or less to a field of view of 180 ° or more. An endoscope characterized by the following.

(2) The image which has an angle of view exceeding 180 ° is electrically processed to mask a portion which is not photographed when the angle of view is less than 180 °. Endoscope.

(3) In the endoscope according to the second item, the image to be masked is enlarged by electrical processing so that the size of the image transmitted on the monitor is substantially the same as the image at an angle of view exceeding 180 °. An endoscope characterized in that:

(4) The endoscope according to item 1, wherein a viewing angle can be optically switched from a viewing range within 180 ° to a viewing range of 180 ° or more.

[Technical Field of the Invention Belonging to the Second Group] The invention belonging to the second group relates to an imaging device for switching the angle of view of an endoscope.

[Prior art of the invention belonging to the second group]
In order to observe both the front direction and the side direction in the body cavity, a direct-view endoscope for observing the front direction and a side-view endoscope for observing the side direction are separately inserted and observed. An observation optical system for observing the front direction and an observation optical system for observing the lateral direction, as disclosed in JP-A-313435, have to be used together with an endoscope having a function of switching the observation direction.

[Problems of the invention belonging to the second group] When an endoscope for observing the front direction and an endoscope for observing the side direction are separately inserted for observation, two endoscopes are inserted into the body cavity of the patient. Since the endoscope was inserted separately, the invasion was large and the burden on the patient was heavy.

On the other hand, in the case where an endoscope having an observation optical system for observation in the front direction and an observation optical system for observation in the side direction and having a function of switching the viewing direction is used, two endoscopes are required. Since two optical systems must be mounted, the outer diameter of the insertion portion of the endoscope becomes very large, and in this case, the invasion to the patient is large and the pain is great. Further, in the conventional side-viewing endoscope, the observation range in the cross-sectional direction with respect to the insertion direction of the endoscope is limited to a narrow range, so that careful attention must be paid so as not to overlook the lesion, and the observation / diagnosis time is increased.

The invention belonging to the second group has been made in view of the above problems, and an object of the invention is to provide an endoscope which is less invasive to a patient and can prevent a lesion from being overlooked.

[Operation of the invention belonging to the second group] The angle of view is 18
In the range of 0 ° or less, observation in the front direction can be performed as in a normal direct-viewing endoscope, and when the angle of view exceeds 180 °, observation of the entire side circumference can be performed.

[Effect of Item (1) of the Second Group] 140 °
With a single observation optical system up to 210 °, the front and side observations are possible, so the outer diameter of the insertion section is smaller than that of an endoscope that has separate observation optical systems for direct and side viewing. Can reduce the invasion of the patient. Further, since the endoscope can be observed in both the direct viewing direction and the side viewing direction only by inserting the endoscope once, the burden on the patient can be reduced as compared with a case where the direct viewing endoscope and the side viewing endoscope are swallowed separately.

Further, when observing the side viewing direction at a wide angle, a 360 ° cross section can be observed in all directions, so that oversight can be reduced.

[Effects of Items (2) and (3) in the Second Group] Since the angle of view can be reduced by switching the angle of view electrically, there is no need to switch the angle of view by optical means, and the size of the imaging unit is reduced. Size can be reduced.

[0089]

As described above, according to the present invention, it is possible to provide an endoscope in which the illumination optical system can be arranged as compact as possible and the balance of illumination light distribution is improved.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram schematically showing an endoscope system according to a first embodiment of the present invention.

FIG. 2 is a front view of a distal end portion of the endoscope according to the first embodiment in a state where an insertion portion is inserted into an intestine.

FIG. 3 is a front view of a distal end portion of the endoscope according to the first embodiment.

FIG. 4 is a vertical cross-sectional view of the vicinity of the distal end of the insertion section taken along the line XX in FIG.

FIG. 5 is a vertical cross-sectional view of the vicinity of the distal end of the insertion section taken along line YY in FIG. 3;

6 is a cross-sectional view of the vicinity of the distal end of the insertion section taken along the line ZZ in FIG.

FIG. 7 is a vertical cross-sectional view of the vicinity of the distal end of the insertion section taken along the line SS in FIG. 6;

8 is a longitudinal sectional view of the vicinity of a light guide fiber bundle cut along the line TT in FIG. 7;

9A is a cross-sectional view of a state where a light guide is assembled to a U-shaped base, and FIG. 9B is a front view of the U-shaped base in an initial state.

FIG. 10 is a detailed longitudinal sectional view of an observation optical system of the endoscope according to the first embodiment.

FIG. 11 is a longitudinal sectional view of a modification of the observation optical system of the endoscope.

FIG. 12 is an explanatory diagram of a situation in which light rays having a viewing angle of 210 ° are incident on a solid-state imaging device of an endoscope.

FIG. 13 shows a state in which a solid-state imaging device of an endoscope is covered with an electronic mask.
It is explanatory drawing of the situation which narrowed the viewing angle to 40 degrees.

FIG. 14 is a front view of a distal end portion of an endoscope according to a second embodiment of the present invention.

FIG. 15 is a front view of a distal end portion of an endoscope according to a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... endoscope, 3 ... insertion part, 10 ... front-end | tip part, 21 ... observation optical system, 26 ... 1st surface part, 27 ... 2nd surface part, 22a,
22b: illumination optical system, 23a, 23b: illumination optical system, P
Reference numeral 1 denotes the center of the observation optical system, A denotes the first axis, and B denotes the second axis.

[Procedure amendment]

[Submission Date] July 13, 2000 (2007.1)
3)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction contents]

As shown in FIGS. 3 and 4, the distal end portion 10 of the endoscope 1 has a distal end hard member 11, and the outer periphery of the distal end portion of the distal end hard member 11 is made of an electrically insulating material. It is covered with a tip cover 12. The distal end cover 12 is fitted and fixed to the distal end hard portion 11. The bending portion 9 of the insertion portion 3 is connected to the rear end of the tip portion 10. The bending portion 9 is configured by covering a bending tube 15 formed by connecting a number of node rings 14 with a rubber tube 16. The bending section 9 is configured to bend toward the pulling side by pushing and pulling four operation wires 17 arranged vertically and horizontally in the insertion section 3 by operating the operation section 2.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction contents]

As shown in FIG. 10, the imaging lens group 25 is composed of a lens group 25a incorporated in a cylinder 74 and a lens group 25b assembled at the tip of a through hole 28 into which the cylinder 74 is fitted. And
The lens group 25a and the lens group 25b are coaxially arranged on the observation optical axis L.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0023

[Correction method] Change

[Correction contents]

The solid-state imaging device 33 is incorporated in the imaging lens barrel 31 as shown in FIG. The imaging lens barrel 31 is connected to the cylinder 74 so as to be fitted around the rear end of the cylinder 74. The solid-state imaging device 33 is provided in the imaging lens barrel 31.
In addition, a substrate, an IC chip, and the like (not shown) are built in, and the CCD unit 32 is constituted by this.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0060

[Correction method] Change

[Correction contents]

In this case, the center of the small illumination optical system 22 is located within the area of the second surface 27 and on the first axis A. The center of the large illumination optical system 23 is located in the area of the first surface 26 and on the first axis A.

[Procedure amendment 6]

[Document name to be amended] Drawing

[Correction target item name] Fig. 4

[Correction method] Change

[Correction contents]

FIG. 4

[Procedure amendment 7]

[Document name to be amended] Drawing

[Correction target item name] FIG.

[Correction method] Change

[Correction contents]

FIG. 10

[Procedure amendment 8]

[Document name to be amended] Drawing

[Correction target item name] FIG.

[Correction method] Change

[Correction contents]

FIG. 14

[Procedure amendment 9]

[Document name to be amended] Drawing

[Correction target item name] FIG.

[Correction method] Change

[Correction contents]

FIG.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Haruhiko Kaiya 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Industrial Co., Ltd. (72) Inventor Hisao Yabe 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. F-term (reference) 2H040 CA12 CA21 4C061 AA00 BB02 CC06 DD03 FF39 FF40 FF43 FF46 JJ06

Claims (1)

[Claims] An observation optical system for observing the inside of a field of view and two or more illumination optical systems for emitting illumination light transmitted by a light guide fiber into the field of view are provided at a distal end of the insertion section. At the end of the endoscope, the observation window of the observation optical system and the illumination window of two or more illumination optical systems are arranged. The observation window of the system is arranged, a straight line passing through the center of the insertion portion and the center of the observation window is defined as a first axis, and a straight line perpendicular to the first axis and passing through the center of the observation window is defined as a second axis. When the region of the distal end surface of the insertion portion is bisected by the second axis, the region portion not including the center of the insertion portion is defined as the first surface portion, and the region portion including the center of the insertion portion is defined as the second surface portion. And the illumination of the light guide of the illumination optical system in which the illumination window is disposed on the first surface. An endoscope wherein the light transmission capability is configured to be smaller than the illumination light transmission capability of the light guide of the illumination optical system in which the illumination window is provided on the second surface.