JPH0527184A - Endoscope - Google Patents

Abstract

PURPOSE:To make the diameter of an insertion part small and to obtain an endoscope image consisting of many picture elements. CONSTITUTION:Self-convergent optical transmission fibers 40 and 42 which are flexible are extended into the flexible insertion part 12 and an objective 36 is arranged on the tip side of the selfconvergent optical transmission fibers 40 and 42; and this objective 36 transmits an image which is made incident on the incidence ends of the self-convergent transmission fibers 40 and 42 to the rear end sides through the optical transmission fibers 40 and 42.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope having a small diameter.

[0002]

2. Description of the Related Art Generally, an endoscope has a long and flexible insertion portion, and an optical fiber bundle composed of a large number of optical fibers, for example, about several thousand, is extended in the insertion portion. Further, an objective lens for expanding the field of view of the endoscope is arranged at the tip portion thereof. The image formed by this objective lens is transmitted through an optical fiber to an eyepiece lens or an imaging lens on the rear end side of the endoscope, and a desired site can be observed with the naked eye or a monitor device. The resolution of such an endoscope depends on the number of optical fibers forming the optical fiber bundle, and the resolution increases as the number of optical fibers increases, and a clearer image of high pixels can be obtained.

[0003]

SUMMARY OF THE INVENTION By the way, in order to alleviate the pain of a patient when inserting an endoscope, or to insert the endoscope into a narrower body cavity or the like so that a narrower region can be accurately observed. The diameter of the insertion portion of the endoscope is being further reduced. However, if the diameter of the insertion portion of the endoscope is reduced, the diameter of the optical fiber bundle must be reduced, and in particular, the insertion channel of the treatment instrument and the like on the accommodation space for installing the illumination system are installed. Due to the problem, the diameter of the optical fiber bundle cannot be increased. Therefore, for example, the diameter of the insertion part is 1 mm
In the case of a small-diameter endoscope, the number of optical fibers serving as an image guide is about several tens, and there is a large restriction on increasing the number of the optical fibers. Therefore, the number of pixels is reduced and the resolution is inevitably low. I didn't get it. An endoscope having such a low resolving power may interfere with diagnosis.
The present invention has been made in view of the above problems, and an object of the present invention is to provide an endoscope capable of obtaining an image of high pixels even if the diameter is reduced.

[0004]

In the endoscope according to the present invention, a flexible self-converging optical transmission fiber is extended in a flexible insertion portion, and an entrance end of the self-converging transmission fiber is provided. The image incident on is transmitted to the rear end side through this self-focusing optical transmission fiber.

Then, a wide range image of the inner wall of the body cavity is made incident on the front end side of the self-converging optical transmission fiber, and this image is transmitted to the rear end side by the self-converging optical transmission fiber to enhance the resolving power of the endoscope. Embodiments of the present invention will be described below with reference to the drawings.

[0006]

FIG. 3 shows the system configuration of an endoscope to which the present invention is applied. The endoscope 10 in this embodiment is configured as an electronic endoscope which is, for example, a nasal cavity endoscope or an ear cavity endoscope. The endoscope 10 includes a flexible insertion portion 12, a light guide cable 14, and an image guide cable 16. The insertion portion 12 is to be inserted into the nasal cavity or the ear cavity and has an outer diameter of, for example, about 1 mm.
The light guide cable 14 and the image guide cable 16 extending from the insertion portion 12 are connected to the light source device 22 by the image guide connector 18 and the light guide connector 20 provided respectively. Note that FIG.
Although the image guide connector 18 and the light guide connector 20 are separately formed, they may be integrally formed.

An illumination lamp 24 is arranged as a light source for illumination in the light source device 22, and the illumination light of the illumination lamp 24 is guided through the light guide cable 14 and the insertion portion 12 and from the tip of the insertion portion 12. The wall of the body cavity is irradiated. Then, the light reflected by the wall of the body cavity enters from the tip of the insertion portion 12, and the insertion portion 12 and the image guide cable 1
It is transmitted to the electronic image pickup unit 26 through the inside of 6. The electronic image pickup unit 26 is provided with an image pickup lens 25 and a high-definition solid-state image pickup device 27 (FIG. 1). After being converted into an electric signal, it is projected as an endoscopic image 30 on an attached monitor device 28. .. Further, in the light source device 22, the insertion portion 12
A bending drive control circuit device 32 for controlling the bending drive control circuit device 32 is provided, and the bending drive control circuit device 32 is electrically connected to a control lever device 34.

As shown in FIG. 1, the insertion portion 1 of the endoscope 10
An objective optical system 36 including a plurality of lenses and an illumination unit 38 are provided at the tip of 2. An image guide 40 formed of a flexible self-converging optical transmission fiber (selfoc fiber: product name) having a diameter of, for example, about 100 μ is optically connected to the objective optical system 36, and the illumination unit 20 is connected to the image guide 40. The light guide 42 is connected. The self-focusing optical transmission fiber forming the image guide 40 is arranged with the optical axis aligned with the objective optical system 36 by the lens frame 37 (FIG. 2).
Is guided to the image guide connector 18 through the insertion portion 12 and the image guide cable 16 (FIG. 3). The light guide 42 is guided to the image guide connector 20 through the insertion portion 12 and the light guide cable. The light guide 42 can be formed by an optical fiber bundle in which a large number of ordinary optical fibers are bundled, but in order to reduce the diameter of the insertion portion 12, a flexible self guide is used as in the image guide 40. It is preferably formed from a convergent optical transmission fiber. Reference numeral 44 is a channel for inserting a treatment tool or the like into the body cavity, and reference numeral 45
Is the entrance.

Further, a bending mechanism for controlling the bending of the insertion portion 12 is arranged in the insertion portion 12. As shown in FIGS. 2A and 2B, this bending mechanism has a shape memory alloy wire 46 embedded in the insertion portion 12, and this shape memory alloy wire 46 is close to the outer skin of the insertion portion 12. It has a substantially U-shape extending in the longitudinal direction at the portion. The tip end side of the shape memory alloy wire 46 is fixed to the main body of the insertion portion 12 with an adhesive 47, and the rear end side thereof is connected to the conducting wire 50 at the connection portion 48 by caulking, for example. In this example,
The shape-memory alloy wire 46 is formed of a bidirectional shape-memory alloy that contracts in length due to heat generated when it is energized via the energizing wire 50 and returns to its original length when cooled.
Even if it is unidirectional, it may be arranged on the opposite sides in the radial direction of the insertion portion 12 to form a pair, or when heated to a predetermined temperature, the length becomes shorter, and the temperature becomes higher than that. You may use the bidirectional shape memory alloy which has the property to expand conversely when it heats up. FIG. 4 shows FIG. 1 and FIG.
The shape memory alloy wire 46 shown in is energized to raise its temperature and bend the insertion portion 12.

As described above, the current-carrying wires 50, 50 for supplying the heating current to the shape memory alloy wire 46 are guided through the inside of the image guide 16 (FIG. 3) from the rear end side of the insertion portion 12, and the image guide connector. It is connected via 18 to the bending drive control circuit device 32 (FIG. 1) provided in the light source device 22. Therefore, the control lever device 3 shown in FIG.
By operating 4, the tip of the insertion portion 12 can be bent in a desired direction.

FIG. 5 shows a state in which the image guide connector 18 is fitted in the connector receiver 58 of the light source device 22. A locking groove 59 is provided on the inner wall of the insertion opening of the connector receiver 58, and the light source device connected to the conducting wire 56 extending from the bending drive control circuit device 32 (FIG. 1) is provided on the bottom wall of the insertion opening. The 22-side contact 54 is arranged. Then, when the connector pin 18a of the image guide connector 18 is inserted into the insertion opening of the contact receiver 58, the fixing ring 19 provided on the connector pin 18a meshes with the locking groove 59, and the image guide connector 18 is received by the connector receiver 58. It is designed to be securely fixed to. In this manner, when the image guide connector 18 is mounted on the connector receiver 58, the contacts 52, 52 come into contact with the light source device 22 side contacts 54, 54, and the bending drive control circuit device 32 is electrically connected to the shape memory alloy wire 46. The image of the tip of the endoscope transmitted from the image guide 40 is projected on the solid-state image pickup element 27 through the image pickup lens 25.

Further, as shown in FIG. 5, the light source device 22 includes a Peltier element 29 for cooling the solid-state image pickup element 27.
Is provided. The Peltier device 29 cools the solid-state imaging device 27 to increase its sensitivity,
For example, an image guide 40 having an extremely small diameter of 100 μ
Even a signal with a small amount of light transmitted through can be reliably read. Reference numeral 31 is a drive circuit for driving the solid-state imaging device 27.

FIGS. 6 and 7 show a male connector 60 in which the image guide connector 18 and the light guide connector 20 are integrated. An image guide 40 and a light guide 42 are guided to the male connector 60 through a connector cable 62, and the image guide 40 and the light guide 42 are guided.
Also, the ends of the light guide 42 are provided in the male connector 60 with metal sleeves 41, 4 made of, for example, stainless steel.
3 is fitted inside. Further, a conducting wire 50 for supplying a heating current to the shape memory alloy wire 46 embedded in the insertion portion 12
(FIG. 2) is also guided through the connector cable 62 to the male connector 60, and is connected to the contact pin 64 protruding from the male connector 60. The male connector 60 is provided with an insertion / removal knob 61 so that the insertion / removal with respect to the female connector 70 provided in the light source device 22 can be easily performed.

As shown in FIG. 7, the image guide 40 and the sleeves 41 and 43 fitted to the ends of the lining and guide 42 project from the male connector 60 through the lead-out holes 65 and 67. These lead-out holes 65 and 67 are formed to have a diameter larger than the outer diameters of the sleeves 41 and 43, respectively, and adjust the optical axes of the image guide 40 and the light guide 42 formed of an ultra-fine self-converging optical transmission fiber. ,
The maximum amount of light can be obtained. Therefore, an optical axis adjusting device described later is housed in the male connector 60, and is controlled by a signal from the light source device 22 via the connection pin 66. It is obvious that the connection holes 71, 73 of the female connector 70 for accommodating the sleeves 41, 43 are also formed in such sizes that the optical axes of the image guide 40 and the light guide 42 can be adjusted.

FIG. 8 schematically shows the optical axis adjusting devices 74 and 76 arranged inside the male connector 60. The optical axis adjusting device 74 controls the image guide 40 with respect to the electronic image pickup device 26.
To adjust the optical axis, and the optical axis adjusting device 76 adjusts the optical axis by centering the light guide 42 with respect to the certification lamp 24. These optical axis adjusting devices 74, 7
Since 6 is structurally the same, the optical axis adjusting device 76 of the image guide 40 will be described.

The optical axis adjusting device 76 has a support fitting 80 having an L-shaped cross section, and one leg of this is fixed to the inner wall of the male connector 60 by a fixing member such as a fixing screw.
Support springs 82, 84 are attached to the inner surfaces of the legs of the support fitting 80 adjacent to each other, and the support springs 82, 84 elastically actuate the sleeve 41 and thus the end of the image guide 40 in the sleeve 41. Support.
Further, the support springs 82 and 84 are sandwiched by the sleeve 41.
Adjusting screws 86 and 88 are arranged on opposite sides of
The image guide 40 can be centered by advancing or retracting these adjusting screws 86, 88 in the axial direction. The adjustment screws 86 and 88 can be moved back and forth by screw drive mechanisms 90 and 90.

FIG. 9 shows such a screw drive mechanism 90. The screw driving mechanism 90 drives the head 87 of the adjusting screw 86 to rotate, and includes actuating arms 92 and 94 arranged on the radially opposite sides of the head 87. These actuating arms 92 and 94 are formed by laminating a large number of piezoelectric elements in the axial direction and mounting these piezoelectric elements on support members 93 and 95. When a voltage is applied to these piezoelectric elements in a predetermined direction via the current-carrying wires 96 and 98, each piezoelectric element expands and contracts, and the operating arms 92 and 94 expand and contract in the axial direction. Therefore, when a pulse voltage is applied to the operating arm 92 via the energizing wire 96 and is extended, the tip of the operating arm 92 forms a rotational moment in the direction of arrow a on the head 87 of the adjusting screw 86. On the contrary, the actuating arm 94 is connected through the electric wire 98.
When a pulse voltage is applied to the head to extend the arm, the tip of the operating arm 94 forms a rotational moment in the direction of arrow b on the head 87 of the adjusting screw 86. The tip of the adjusting screw 86 is arranged in the recess 41a formed in the sleeve 41, and therefore,
Even if the adjusting screw 86 rotates, the positional deviation with respect to the sleeve 41 does not occur.

The energizing lines 96 and 98 for supplying the electric signals for controlling the expansion and contraction of the operating arms 92 and 94 in this way are shown as energizing cables 99a in FIG.
It is guided through the male connector 60 together with the zero current-carrying cables 99b, 99c, 99d. Then, it is connected to the light source device 22 via the female connector 70 by the contact pins 66, 66 shown in FIG.

FIG. 10 shows the arrangement of the optical axis adjusting device 74 on a plane perpendicular to the optical axis of the image guide 40. According to the optical axis adjusting device 74, the ends of the image guide 40 are supported on the support fitting 80 by the support springs 82 and 84, and the image guide 40 is supported by the support springs 82 and 84.
Since the adjusting screws 86 and 88 are movable against the biasing force of 84, the optical axis of the image guide 40 can be arranged at a required position by advancing and retracting the adjusting screws 86 and 88 individually. it can. Reference numerals 85 and 87 denote guide support fittings, which uniformly transmit the spring force to the image guide 40 and the light guide 42. In FIG. 10, the support springs 82, 84 and the adjusting screws 86, 88 are arranged with their axes oriented vertically and horizontally, but the invention is not limited to this and other arrangements are possible as long as the optical axes can be adjusted. Obviously, it is possible to have an arrangement.

It is preferable that the optical axes of the image guide 40 and the light guide 42 are automatically adjusted when the male connector 60 is attached to the female connector 70. The image guide 4 is provided on a part of the pixels of the solid-state image sensor 27 (FIG. 1).
When the image signal from 0 is not input, a blank portion 31 is generated below the endoscopic image 30 of the monitor device 28 as shown in FIG. 11A, and in this case, the image signal is applied to all pixels. 11 is input and a control signal is sent from the control device (not shown) to the optical axis adjusting device 74 of FIG. 8 so that the endoscopic image 31 as shown in FIG.
Adjust the optical axis of. Further, the focus adjustment of the endoscopic image 31 can be automatically performed based on the output signal of the solid-state imaging device 27. For example, when the output signal as shown in FIG. The image pickup lens 25 (FIG. 8) is moved along its optical axis by a linear actuator, and is controlled so as to obtain an output signal as shown in FIG. 12B.

Further, the optical axis of the light guide 42 can be adjusted as shown in FIG. In FIG. 13A, a photo sensor 55 is installed around the light guide 42 or the sleeve 43 that houses the light guide 42, and the output of the photo sensor 55, that is, the amount of light incident from the certification lamp 24 is not shown in the drawing. The control device controls the optical axis adjusting device 76 in FIG. Further, in FIG. 13B, the reflecting surface 43a is arranged on the end surface of the sleeve 43,
A laser beam is emitted from the laser diode 53 and the reflected light is received by the photodiode 57. Based on the output signal of the photodiode 57, a control signal from a control device (not shown) can be sent to the optical axis adjusting device 76 (FIG. 8) to maximize the incident light amount of the light guide 42 having a small diameter.

Therefore, according to the endoscope 10, since the image guide 40 and the lining and the guide 42 are formed by extending the self-converging optical transmission fiber in the insertion portion 12, an endoscopic image 30 having an extremely high pixel is obtained. In addition, by embedding the memory shape alloy wire 46 in the insertion portion 12, the insertion portion 12 can be made extremely thin and the bending can be controlled. Further, even such a small-diameter self-converging optical transmission fiber can automatically adjust the respective optical axes by the optical axis adjusting devices 74 and 76, so that it is extremely easy to handle.

[0023]

As is apparent from the above, according to the present invention,
By extending the self-converging optical transmission fiber in the flexible insertion portion, an endoscopic image of extremely high pixels can be obtained even if the diameter is reduced.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of an endoscope according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an external appearance and an internal arrangement of an endoscope insertion portion.

FIG. 3 is a configuration diagram of an endoscope system using the endoscope of FIG.

FIG. 4 is a perspective view showing an outline of a portion near a distal end portion of the endoscope shown in FIG.

FIG. 5 is an explanatory diagram showing a state in which the cable connector of the light guide cable is connected to the light source device.

FIG. 6 is an explanatory view showing a male connector according to another embodiment together with a female connector.

FIG. 7 is a perspective view showing a mounting surface of the male connector of FIG.

FIG. 8 is an explanatory view schematically showing the internal structure of the male connector of FIG.

FIG. 9 is an explanatory diagram showing an operation of a screw drive mechanism of the optical axis adjusting device.

FIG. 10 is an explanatory diagram showing an arrangement of an optical axis adjusting device.

FIG. 11 is an explanatory diagram of optical axis adjustment of the image guide.

FIG. 12 is an explanatory diagram of focus adjustment of an endoscopic image.

FIG. 13 is an explanatory diagram for adjusting the optical axes of the lining and the guide.

[Explanation of symbols]

10 ... Endoscope, 12 ... Insertion part, 14 ... Light guide cable, 16 ... Image guide cable, 18, 20 ... Cable connector, 22 ... Light source device, 24 ... Certification lamp,
26 ... Electronic imaging device, 28 ... Monitor device, 30 ... Endoscopic image, 36 ... Objective optical system, 40 ... Image guide, 4
1, 43 ... Sleeve, 42 ... Light guide, 46 ... Shape memory alloy wire, 50, 56 ... Conducting wire, 60 ... Male connector,
70 ... Female connector, 74, 76 ... Optical axis adjusting device, 90 ...
Screw drive mechanism.

Front Page Continuation (72) Inventor Hisao Yabe 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (72) Hideo Ito 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optics Industrial Co., Ltd. (72) Inventor Yu Konomura 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Industry Co., Ltd. (72) Inventor Iso Tsukakoshi 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Industry Co., Ltd. (72) Inventor Akio Nakata 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Industry Co., Ltd. (72) Inventor Yoshinao Daimei 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Industry Co., Ltd. (72) Inventor Koichi Tatsumi 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Industry Co., Ltd. (72) Inventor Yasuo Mori 2-43-2 Hatagaya, Shibuya-ku, Tokyo Ori Inpass Optical Co., Ltd. (72) Inventor Fujimura Takeshi Nao 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (72) Inventor Ryusuke Nozawa 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (72) Inventor Takao Okada 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Co., Ltd.

Claims (1)

Claim: What is claimed is: 1. A flexible self-converging optical transmission fiber is extended in a flexible insertion portion, and an image made incident on an incident end of the self-converging transmission fiber is self-converging. An endoscope characterized in that the light is transmitted to the rear end side through a convergent optical transmission fiber.