JPH0555043B2 - - Google Patents

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to an objective optical system having an entrance aperture on the distal end surface of the distal end of an insertion section, and an objective optical system disposed behind the objective optical system, The present invention relates to an endoscope that includes a solid-state imaging device that converts captured images into electrical signals.

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

By the way, for safety reasons, it is necessary to completely insulate the solid-state image sensor and the outer wall (inside the body) of the distal end of an endoscope that uses a solid-state image sensor. Therefore, it is generally molded from resin, which is an insulator.

In this case, the outer wall should be made of resin with consideration for surface smoothness, moldability, and chemical resistance. on the other hand,
The area around the solid-state image sensor should be made of a resin that is difficult to crack and has excellent insulation properties, such as Ryton, which contains 40% glass fiber, in consideration of insulation properties.

[Object of the Invention] The present invention has been made in view of the above-mentioned points, and by supporting a solid-state image sensor (solid-state image sensor) with an insulating cover, both of the above desired conditions can be satisfied, and it is safe. The purpose is to provide an endoscope that can obtain good images.

[Summary of the Invention] The present invention provides an endoscope in which an imaging means for focusing an image of a subject on an imaging surface of a solid-state imaging device in an objective optical system is formed, and an insulating cover having a substantially cylindrical shape with an inner edge at the bottom. is fixed to the inner wall of the distal end main body, and the imaging device is supported inside thereof.

[Embodiments of the Invention] The present invention will be specifically described below 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.

The endoscope 1 of the first embodiment has a flexible insertion section 2 with a small diameter that can be inserted into a body cavity, etc., and the distal end thereof has a slightly larger diameter and accommodates an imaging means, an illumination optical system, etc. A component 3 is formed.

In the tip (configuration) section 3, a tip body 4 is formed using a hard member such as metal, and is eccentric, for example, upwardly from the central axis O (indicated by a two-dot chain line) of the tip section 3, and is used for imaging optics. system is installed.

That is, the front end of the through hole formed eccentrically above the center of the tip body 4 is covered with a cover glass 5,
An objective lens system 6 forming an objective optical system is housed in the back thereof via a lens frame 7, and the center of the imaging plane is located on the linear optical axis O' of the objective lens system 6 at a position that becomes the focal plane. A solid-state image sensor 9 such as a charge-coupled device (CCD) is disposed so as to face the solid-state image sensor 9, and an imaging means for forming an image of a subject on an imaging plane by the objective optical system is formed.

The solid-state image sensor 9 is fixed to the inner wall of the tip body 4 via an insulating cover 10. This insulating cover 10 is formed of a substantially cylindrical body with an inner edge provided at the bottom, and the inner edge serves as a flare aperture. The imaging element arranged inside has an imaging surface formed by regularly arranging a large number of light receiving elements, and is protected by a transparent plate 11 such as a protective glass. Each electrode of the solid-state image sensor 9 is electrically connected to each terminal 12 fixed to the inside of the insulating cover 10 by soldering or brazing, and receives a signal from the hand side via a lead wire 13 connected to each terminal 12. It is possible to apply a reading clock signal and to read signals (signal capture) by applying the clock signal.

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 by 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 formed by bundling flexible optical fibers.
The rear end can be detachably attached to a light source device (not shown). Thus, the light from the illumination lamp in the light source device is condensed and irradiated onto the rear end of the attached light guide 15, and the irradiated illumination light is emitted from the front end of the light guide 15. Via the light distribution lens 14, the objective lens system 6 can substantially uniformly illuminate the range that can be imaged on the imaging surface.

In addition to the above illumination optical system, as shown in Figure 2,
A treatment instrument channel 16 and an air/water supply channel 17 can be formed.

Note that the rear end side of the tip main body 4 is fitted into a cover member 18 whose front end side is enlarged in diameter, and the cover member 1
A light guide 15, a treatment instrument channel 16, and an air/water supply channel 17 are located inside the narrow diameter part of 8.
A curved portion is formed to allow the insertion of such items. The rear side of this curved portion is connected to a flexible portion whose diameter is further reduced (not shown).

The lead wires 13 connected to each electrode of the solid-state image sensor 9 are connected to the operation section on the hand side or a video processing section (not shown) on the outer periphery of the operation section, and the read signals are sent to an amplifier in the video processing section. It is becoming amplified by If the solid-state image sensor 9 has a mosaic-like three primary color filter arranged in front of the imaging surface, the sample and hold circuit in the amplifier separates each color signal, and the separated color signals are sent to each color amplifier. After sufficient amplification, the signal is displayed on a display device such as a color cathode ray tube while being swept with horizontal and vertical deflection signals.

On the other hand, when using a color-sequential illumination method illumination means that sequentially illuminates 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 set to each of the three primary colors. By sequentially illuminating the image with light of different wavelengths and switching in synchronization with each other, each color amplifier turned on by an analog switch is amplified every frame period, and the amplified colors are displayed, so that the image can be visually recognized as a color image. There is. In addition, it is also possible to display the three primary colors simultaneously using a memory or the like.

[Effects of the Invention] As described above, according to the present invention, since the solid-state image sensor is supported by the insulating cover, it is possible to completely maintain insulation between the solid-state image sensor and the outer wall (inside the body), and the inner edge of the insulating cover The part exhibits the effect of flare aperture.

[Brief explanation of the drawing]

1 and 2 relate to a first embodiment of the present invention, FIG. 1 is a cutaway side view showing the vicinity of the tip of the first embodiment, and FIG. 2 is a cross section taken along the line A-A in FIG. 1. It is a diagram. 1... Endoscope, 2... Insertion part, 3... Tip part,
4...Tip body, 6...Objective lens system, 9...
Solid-state image sensor, 10...Insulating cover, 11...Transparent plate, 14...Light distribution lens, 15...Light guide, 16... Channel for treatment instrument, 17... Air supply/water supply channel.

Claims (1)

[Claims] 1. An objective optical system having an entrance opening on the distal end surface of the distal end of the insertion section; and an objective optical system disposed behind the objective optical system,
In an endoscope having a solid-state imaging device that converts an image formed by the objective optical system into an electrical signal, the distal end portion is fixed to the inner wall of the main body, supports the imaging device inside, and has an inner edge portion at the bottom thereof. An endoscope characterized by having a substantially cylindrical insulating cover provided with.