JPS6066224A - Endoscope using solid-state image pickup device - Google Patents

Abstract

PURPOSE:To make a front end part small-sized by constituting an endoscope so that the optical axis of an incidence-side part in an objective optical system is off the center of the front end part. CONSTITUTION:In an endoscope 1, a slightly large-diameter front end constituting part 3 is formed in the front end side of a flexible insertion part 2, and an image pickup means, an illumination optical system, etc. are stored in this part 3. In the front end part 3, a front end part body 4 is formed with a solid member such as a metal or the like, an optical system for image pickup is provided eccentrically from a center O of the front end part 3 in this body 4. The front end of a transmission hole is covered with a cover glass 5, and an objective lens system 6 is stored in the depth through a lens frame 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an endoscope that uses a solid-state image sensor in which the optical axis of an objective optical system is decentered from the center of the end portion of the endoscope.

[Technical Background of the Invention and Problems Therewith] In recent years, various endoscopes using solid-state imaging devices such as charge-coupled devices (CODs) as imaging means have been proposed.

The above-mentioned solid-state image sensor is generally rectangular or square in shape, so when it is housed in the distal end of the insertion tube, if it is installed in the center of the distal end, it will be difficult to secure enough space for other illumination means [1 channel, etc.]. There was a problem that there was no.

For this reason, as disclosed in Japanese Patent Application Laid-Open No. 58-46922, a mirror or the like is used to reflect the image and guide it to the carrying edge surface of a solid Ilil elementary image placed parallel to the axis of the insertion section or tip. There is a conventional example.

However, even in this conventional example, since the light guiding member such as a mirror forming the imaging means is disposed at the center of the distal end, as described above, the illumination means (illumination optical system) or the treatment instrument channel etc. The space for
There are problems in that the illumination intensity tends to be insufficient, the treatment tools that can be used are limited, and it becomes difficult to adequately perform treatment using the treatment tools.

[Object of the Invention] The present invention has been made in view of the above-mentioned points, and it is an object of the present invention to provide an endoscope using a solid-state image pickup device that allows sufficient space for forming illumination means or treatment instrument channels. With the goal.

[Summary of the Invention] The present invention provides an endoscope in which an imaging means for forming an image of a subject on an imaging surface of a solid-state image sensor in an objective optical system is formed, in which an optical axis of an incident side portion that extends d3G to the objective optical system is provided. By forming the light beam eccentrically from the center of the distal end of the endoscope, it is possible to secure a sufficient space for forming the illumination means and the like.

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

1 and 2 relate to the first embodiment of the present invention, FIG. 1 shows the distal end of the insertion section of the endoscope of the first embodiment, and FIG. 2 is taken along line A-A in FIG. 1. A cross-sectional view is shown.

In the endoscope 1 of the first embodiment, a flexible insertion section 2 with a small diameter that can be inserted into a body cavity has a slightly larger diameter on the distal end side to accommodate a transportation means, an illumination optical system, etc. A tip forming portion 3 is formed.

In the tip (configuration) section 3, a tip body 4 is formed using a hard member such as a metal, and is eccentric to the upper side from the central axis 0 (indicated by a two-dot chain line) of the tip section 3, and is used as an optical device for imaging. system is installed.

That is, the front end of a through hole formed eccentrically above the center of the tip main body 4 is covered with a cover glass 5, and an objective lens system 6 forming an objective optical system is housed in the back thereof via a lens frame 7. On the linear optical axis O' of the objective lens system 6,
An imaging means in which a solid-state image sensor 9 such as a charge-coupled device (COD) is arranged so that the center of the m image plane faces the focal plane, and the objective optical system forms an image of the subject on the m image plane. is formed.

The solid-state ms element 9 is connected to the tip #i via an insulating cover 10.
The i section is fixed to the inner wall of the main body 4, and the imaging surface formed by regularly arranging a large number of light receiving elements is protected by a transparent plate 11 such as a protective glass.

Each electrode of the solid-state image sensor 9 is connected to each terminal 12 fixed to the inside of the insulating cover 10 by soldering, brazing, etc.
Through the lead wire 13 connected to each terminal 12, it becomes possible to apply the clock number 18 for signal reading from the hand side, or to read the signal (signal capture) by applying the tarok signal. ing.

An illumination optical system is formed in the lower part of the distal end part 3 where the imaging means is formed eccentrically on the upper side, and a wide space is secured due to the eccentricity.

That is, the front end of the through hole formed on the lower side of the tip main body 4 is closed by the light distribution lens 14, and the light guide 15 is inserted through the light distribution lens 14 so that the front end serving as the output end faces the back of the light distribution lens 14. This light guide 15 is a flexible optical m
The light kite 15, which is formed by bundling H1 ()1 fibers, is inserted into the insertion portion 2, and its rear end can be detachably attached to a light source device (not shown). Therefore, the light from the illumination lamp in the light source device is condensed and irradiated onto the rear end of the light guide 15 installed, and the irradiated illumination light is directed from the front end of the light guide 15. Via the light distribution lens 14, the range that can be imaged on the imaging surface by the objective lens system 6 can be illuminated substantially uniformly.

In addition to the illumination optical system described above, as shown in Figure M2, a treatment instrument channel 16 and an air/water supply channel 17 can be formed.

The rear end of the tip main body 4 is fitted into a cover member 18 whose front end is enlarged in diameter, and a light guide 15 is provided inside the narrow diameter portion of the cover member 18. Treatment instrument channel 16.
A curved portion is formed into which the air/water channel 17 and the like can be inserted. The rear side of this curved portion is connected to a flexible portion whose diameter is roughly reduced (as shown in the diagram).

Incidentally, the lead wires 13 connected to each electrode of the solid-state mechanical element 9 are connected to the operating section on the hand side or the outer periphery of the operating section (not shown).
It is connected to a video processing unit, and the read signal is amplified by an amplifier within the video processing unit. The solid-state image sensor 9 is arranged in a mosaic pattern in front of the m image plane.
For those equipped with primary color filters, each color signal is separated by a sample and hold circuit in the amplifier, and the separated color signals are further sufficiently amplified by each high-speed amplifier, and then the color signal is output while being swept by horizontal and vertical deflection signals. It is intended to be displayed on a display device such as a cathode ray tube.

On the other hand, in the case of using a color sequential illumination method illumination means in which the rear end surface of the light guide 15 is sequentially illuminated with light of each wavelength of the three primary colors, an analog switch or the like is used, and the analog switch is connected to each of the three primary colors. Each wavelength of light is sequentially illuminated, switched synchronously, and amplified for each frame period by each steep amplifier turned on by an analog switch, and displayed in each amplified color.
This allows the image to be visually recognized as a color image. In addition, it is also possible to display the three primary colors simultaneously using a memory or the like.

According to the first embodiment of the present invention configured in this manner, the (linear) optical axis 0' of the objective optical system is formed eccentrically from the central axis O of the tip 3, so that the light A wide space can be formed on the side opposite to the axis O', and a light line]-guide 15. Sufficient space can be secured in which the treatment instrument channel 16 and the air/water supply channel 17 can be provided. Therefore, sufficient illumination can be provided without insufficient illumination intensity, and the image captured and displayed by the imaging optical system will be clear, allowing for accurate diagnosis. A variety of treatment tools can be used for therapeutic treatment, allowing appropriate treatment.

Further, since the distal end portion 3 can be used efficiently, the distal end portion 3 can be made small in diameter, which has the advantage of reducing the pain caused to the patient during insertion.

FIGS. 3 and 4 show the tip of a second embodiment of the invention.

In this embodiment, the objective optical system is formed eccentrically upward from the center of the tip 21, as in the first embodiment. That is, the through hole eccentrically upward from the central axis O of the tip portion 21 is closed with a cover glass 5, and an objective lens system 6 is disposed behind the cover glass 5. A mirror 23 is fixed through a frame 22 at an angle of 45 degrees with respect to the optical axis O'. This mirror 23
A solid-state image sensor 9 is disposed so that the ms plane of the focal plane of the objective lens system 6 is located on the lower reflection optical axis (in the figure, where the light is reflected at right angles).

In the examples shown in FIGS. 3 and 4 above, the imaging plane is located close to the central axis O and arranged parallel to the central axis O.

The front end of the through hole formed on the lower side of the tip portion 21 is closed with the light distribution lens 14 as in the first embodiment, and
A light guide 15 for illumination is arranged behind the light distribution lens 14.

On both sides of the objective lens system 6, a treatment instrument channel 16 and an air/water supply channel 17 are formed, as shown in FIG.

In this embodiment as well, at least the optical axis 0', which is the incident side (where the incident light is incident), of the objective optical system is eccentrically formed with respect to the central axis O, and the solid me element 9 is arranged near the central axis O (
In other words, since the structure is such that the imaging surface is oriented in the direction of the central axis O' force (the part closest to the largest diameter of the tip 21), even if a solid-state imaging device 9 with a wide imaging surface is used. This has the advantage that the tip portion 21 can be made sufficiently small in diameter, and the space for forming the illumination optical system and the like other than the image conveying means can be made sufficiently large.

FIG. 5 shows the tip of a third embodiment of the present invention.

In this embodiment, a prism 31 is used in place of the mirror 23 in the second embodiment. Further, the lens 6A forming the objective lens system 6 is attached to the end surface of the prism 31 on the entrance q'' side.

Note that the prism 31 is fixed at the side surface (the surface perpendicular to the plane of the paper).

The rest is the same as in the second embodiment, and the same members are given the same reference numerals. This embodiment also has almost the same advantages as the second embodiment, in addition to the fact that a part of the lens 6A of the objective lens system 6 is formed by attaching it to the prism 31, and that the refractive index is lower than 1. By using the large prism 31, the optical path to the m image plane can be made shorter than in the case of the second embodiment, and the length of the light end 21 can be made shorter.

In addition to the embodiments described above, for example, a lamp or a light emitting diode may be disposed within the tip portion 3.21 without using the light guide 15 as an illumination means.

Also, light guide 15. The treatment instrument channel 16 and the like do not have to be formed in the above-mentioned positions, and since the space in which they can be formed is widened, there is also the advantage that design etc. become easier.

[Effects of the Invention] As described above, according to the present invention, the optical axis of the incident side portion of the objective optical system is eccentrically formed from the center of the tip. In addition to securing a space where you can form without running out of capacity,
Since these can be formed efficiently, the tip portion can be made smaller. Therefore, the pain caused to the patient during insertion can be reduced.

[Brief explanation of the drawing]

1 and 2 relate to the first embodiment of the present invention, FIG. 1 is a side view showing the distal end portion of the first embodiment with the periphery cut away, and FIG. The sectional views, FIGS. 3 and 4, relate to the second embodiment of the present invention, FIG. 3 is a side view showing the vicinity of the tip section cut away, and FIG. 4 is a sectional view taken along the line B-B in FIG. 3. Fifth
The figure is a cutaway side view showing the vicinity of the tip of a third embodiment of the present invention. 1...inside? ! v 2...Insertion section 3.21...Tip section 4...Tip section main body 6...Objective lens system 9...Solid-state imaging device 11...Transparent plate
14... Light distribution lens 15... Light guide 16... Treatment instrument channel 17... Air/water supply channel 23... Mirror 31... Prism Figure 1 ♂ Figure 2 Figure 3 IXI v -5 Figure 4 Continued from page 1 Inventor: Atsushi Miyazaki Inventor: Ken Sugawara Hatake Co., Ltd., Shibuya-ku, Tokyo

Claims (1)

[Scope of Claims] (1) A distal end component formed on the distal end side of an insertion section that can be inserted into a body cavity, etc., is capable of forming an image of a subject on an imaging surface of a solid-state image sensor using an objective optical system. In the endoscope in which the optical axis of the objective optical system on which the incident light is incident is eccentrically formed from the center of the distal end component, the solid-state imaging device is used. Endoscope. (2) Endoscopic vision using the solid-state imaging device according to claim 1, wherein the optical axis of the objective optical system is formed in a straight line parallel to the central axis of the tip component. mirror. (3) The optical axis of the objective optical system consists of a parallel optical axis on the incident side that is parallel to the central axis of the tip component, and a reflected optical axis that is made by reflecting the parallel optical axis at right angles with a mirror or prism. An internal FA mirror using the solid-state image sensor according to claim 1. (4) The solid-state imaging device according to claim 2, wherein the solid-state imaging device is arranged such that its lff1 image plane is perpendicular to the central axis of the tip component. Endoscope used. (5) The solid-state imaging device according to claim 3 is used, wherein the solid-state imaging device is arranged such that its imaging surface is parallel to the central axis of the tip component. Endoscope.