JPH07104489B2 - Endoscope - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to an endoscope using a solid-state image sensor formed by eccentricizing an optical axis of an objective optical system from a center of a tip portion of the endoscope.

[Technical Background of the Invention and Problems Thereof] In recent years, various endoscopes using a solid-state imaging device such as a charge-coupled device (CCD) as an imaging means have been proposed.

Since the solid-state imaging device is generally rectangular or square-shaped, when it is housed in the distal end portion of the insertion portion, if it is mounted at the center of the distal end portion, it will not be possible to secure sufficient space for other illumination means, treatment instrument channels, or the like. There was such a problem.

Therefore, as disclosed in JP-A-58-46922, a conventional example in which the light is reflected by a mirror or the like and guided to the image pickup surface of a solid-state image pickup element arranged parallel to the axis of the insertion portion or the tip portion. There is.

However, also in this conventional example, since the light guide member such as a mirror forming the image pickup means is disposed in the center of the tip end portion, as described above, the illumination means (illumination optical system) or the treatment instrument channel etc. However, there is a problem that the space for the treatment is narrowed, the illumination intensity is insufficient, and the treatment tools that can be used are limited, so that it is difficult to sufficiently perform the medical treatment using the treatment tools.

[Object of the Invention] The present invention has been made in view of the above points, and an object of the present invention is to provide an endoscope using a solid-state imaging device that allows a sufficient space for forming a fluid channel or a treatment instrument channel. And

SUMMARY OF THE INVENTION According to the present invention, in an endoscope in which an image pickup means for forming an image of a subject is formed on an image pickup surface of a solid-state image pickup device by an objective optical system, a distal end portion of an insertion portion is bisected in a radial direction. The solid-state imaging device is arranged in the vicinity of the central axis of the tip of the insertion section, with its imaging surface oriented in the direction perpendicular to the central axis, and at the portion of the tip of the insertion section on the imaging surface side, It is characterized in that an objective optical system and a fluid channel or a treatment instrument channel are provided side by side.

Embodiments of the Invention Hereinafter, the present invention will be specifically described with reference to the drawings.

1 and 2 relate to a first embodiment of the present invention, FIG. 1 shows a distal end portion of an insertion portion of an endoscope of the first embodiment, and FIG. 2 is a line AA of FIG. A sectional view is shown.

The endoscope 1 according to the first embodiment has a small-diameter and flexible insertion portion 2 that can be inserted into a body cavity or the like, and has a slightly larger diameter on the distal end side to accommodate an imaging means, an illumination optical system, and the like. The constituent part 3 is formed.

The tip (configuration) portion 3 has a tip portion main body 4 formed of a hard material such as metal, and is eccentric from the central axis O (indicated by a chain double-dashed line) of the tip portion 3 to the upper side, for example, and is used for optical imaging. A system is provided.

That is, the front end of the through hole formed eccentrically from the center of the tip portion main body 4 is covered with the cover glass 5, and the objective lens system 6 forming the objective optical system is housed in the back through the lens frame 7. On the linear optical axis O ′ of the objective lens system 6, a reflecting mirror 23 is formed by the frame 22 with respect to the optical axis O ′.
It is tilted and fixed. A solid-state image pickup device 9 is arranged so that the image pickup surface is located at the focal plane position of the objective lens system 6 on the reflection optical axis on the lower side (in the drawing) which is reflected at a right angle by the mirror 23. ing. That is, the solid-state imaging device 9 is arranged such that the distal end portion of the insertion portion is bisected in the radial direction, and the imaging surface thereof is oriented in the direction perpendicular to the central axis in the vicinity of the central axis. Then, a clock signal for signal reading can be applied from the hand side through a lead wire (not shown) connected to each of the electrode terminals, or a signal can be read (signal acquisition) by applying the clock signal. It has become.

An illumination optical system is formed on the lower side of the distal end portion 3 which is eccentrically formed on the upper side and in which the imaging means is formed, and which has a wide space secured by the eccentricity.

That is, the front end of the through hole formed on the lower side of the tip portion main body 4 is closed by the light distribution lens 14, and the light guide 15 is inserted so that the front end serving as the emission end faces the back of the light distribution lens 14. The light guide 15 is formed by bundling flexible optical fibers (fibers) and is inserted through the insertion portion 2 into the light guide 15. The rear end of the light guide 15 can be detachably attached to a light source device (not shown). Has become. Then, the light from the illumination lamp in the light source device is condensed and emitted to the rear end of the attached light guide 15, and the emitted illumination light is emitted from the front end of the light guide 15. Light distribution lens 14
After that, the range in which an image can be formed on the imaging surface by the objective lens system 6 can be illuminated substantially uniformly.

The lead wires connected to the respective electrodes of the solid-state image sensor 9 are connected to a video process unit (not shown) on the hand side operation unit or the outer periphery of the operation unit, and the read signal is output by an amplifier in the video process unit. It is supposed to be amplified. In the case where the solid-state image pickup device 9 has a mosaic-type three primary color filter arranged in front of the image pickup surface, each color signal is separated into each color signal by the sample hold circuit in the amplifier, and the separated color signal is divided by each color amplifier. Further, after sufficiently amplified, it is displayed on a display device such as a color cathode ray tube while being swept by horizontal and vertical deflection signals.

On the other hand, in the case of using a color-sequential illumination type illumination means for sequentially illuminating the rear end surface of the light guide 15 with light of each wavelength of the three primary colors, an analog switch or the like is used, and the analog switch is used for each of the three primary colors. The color image is visually recognized as a color image by switching in synchronism with sequentially illuminating with light of a wavelength, amplifying each frame period by each color amplifier conducted by an analog switch, and displaying each amplified color. . It is also possible to display the three primary colors simultaneously by using a memory or the like.

As shown in FIG. 2, a treatment instrument channel 16 and a fluid channel 17 for air supply / water supply are formed near both sides of the objective lens system 6. That is, the objective optical system, the treatment tool channel 16 and the fluid channel 17 are provided side by side at the portion of the distal end of the insertion section on the imaging surface side.

According to the first embodiment of the present invention thus constructed, the optical axis O ′ of the objective optical system is formed so as to be decentered from the central axis O of the tip portion 3, Image sensor 9
Is arranged in the vicinity of the central axis O so that the imaging surface faces the central axis O ′ direction, and the treatment tool channel 16 and the fluid channel 17 for air supply / water supply are provided on the imaging surface side. Since it is formed, even if the solid-state image pickup device 9 having a wide image pickup surface is used, the diameter of the tip portion 4 can be made sufficiently small, and the space for forming the illumination optical system other than the image pickup means can be made sufficiently wide. There is an advantage.

FIG. 3 shows the tip portion of the second embodiment of the present invention.
In this embodiment, a right-angle reflecting prism 31 having a refractive index larger than 1 is used instead of the reflecting mirror 23 in the first embodiment. Further, a lens 6A forming a part of the objective lens optical system 6 is attached to the incident end surface of the prism 31.

The prism 31 has a side surface (a surface perpendicular to the plane of the drawing) fixed inside the tip end body 4. Since other configurations are similar to those of the first embodiment, the same members are designated by the same reference numerals and detailed description thereof will be omitted.

This embodiment has almost the same advantages as those of the first embodiment, and also a lens forming a part of the objective lens optical system 6.
By forming 6A by adhering it to the prism 31 and by using the prism 31 having a refractive index larger than 1, the optical path to the image pickup surface can be made shorter than in the case of the first embodiment. The advantage is that the length of the tip portion main body 4 can be shortened.

In addition to the above-described respective embodiments, for example, a lamp or a light emitting diode can be arranged in the tip portion 3 without using the light guide 15 as an illuminating means.

[Effects of the Invention] As described above, according to the present invention, an objective optical system and a fluid channel for air supply, water supply, etc. are provided on one side of one end of the insertion section that is divided into two by the imaging surface of the solid-state image sensor. Or, because the objective optical system and the treatment instrument channel are installed side by side,
It is possible to effectively arrange the fluid channel and the treatment instrument channel without increasing the thickness of the endoscope distal end portion.

In addition, on the observation monitor, it is possible to observe air supply / water supply or treatment suitable for the direction of the visual field. That is, since the fluid channel or the treatment tool channel is arranged near the objective optical system, this channel appears to extend straight from the front to the back on the monitor. In this case, if the channel is separated from the objective optical system, it appears as if it extends from the lateral direction to the back on the monitor. Therefore, according to the present invention, there is an effect that the operation is easy.

[Brief description of drawings]

1 and 2 relate to the first embodiment of the present invention, and FIG. 1 is a side view showing a notch around the tip of the first embodiment, and FIG.
1 is a cross-sectional view taken along the line AA of FIG. 1, and FIG. 3 is a side view showing a notch around a distal end portion of an endoscope of a second embodiment of the present invention. 1 ... Endoscope, 2 ... Insertion part 3 ... Tip part, 4 ... Tip part body 6 ... Objective lens system, 9 ... Solid-state image sensor 11 ... Transparent plate, 14 ... Light distribution lens 15 ...... Light guide 16 ...... Treatment tool channel 17 ...... Air supply / water supply channel 23 ...... Mirror, 31 ...... Prism

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yu Konomura 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (72) Inventor Atsuyuki Miyazaki 2-43-2 Hatagaya, Shibuya-ku, Tokyo No. Olympus Optical Co., Ltd. (72) Inventor Hisao Yabe 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (72) Inventor Takeaki Nakamura 2-43 Hatagaya, Shibuya-ku, Tokyo No. 2 Olympus Optical Co., Ltd. (72) Inventor Kazutake Sugawara 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (56) Reference JP-A-52-55428 (JP, A) ) Actual opening 57-40408 (JP, U) Actual opening 55-146106 (JP, U) Actual opening 51-153 (JP, Y2)

Claims (2)

[Claims] 1. An objective optical system having an entrance opening on the tip surface of the tip of the insertion section, an optical element provided behind the objective optical system for bending light emitted from the objective optical system in a direction perpendicular to the objective optical system, In an endoscope having a solid-state imaging device for converting an image formed by an objective optical system into an electric signal, the solid-state imaging device is provided with a distal end portion of the insertion portion so as to divide the distal end portion of the insertion portion into two in a radial direction. The image pickup surface is arranged in the vicinity of the central axis in a direction perpendicular to the central axis, and the objective optical system and the fluid channel are provided side by side on the image pickup surface side portion of the distal end of the insertion portion. The characteristic endoscope. 2. An objective optical system having an entrance opening on the tip surface of the tip of the insertion section, an optical element provided behind the objective optical system for bending light emitted from the objective optical system in a perpendicular direction, In an endoscope having a solid-state imaging device for converting an image formed by an objective optical system into an electric signal, the solid-state imaging device is provided with a distal end portion of the insertion portion so as to divide the distal end portion of the insertion portion into two in a radial direction. The image pickup surface is arranged in the vicinity of the central axis in a direction perpendicular to the central axis, and the objective optical system and the treatment instrument channel are provided side by side at the image pickup surface side portion of the distal end portion of the insertion portion. An endoscope characterized in that.