JPH0513283B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an endoscope in which a solid-state imaging device is disposed in the distal end component, and an imaging method for forming an endoscopic image on the light-receiving surface of the solid-state imaging device. The present invention relates to an endoscope in which a solid-state imaging device or illumination means is held by a lens body constituting at least a part of an optical system, thereby simplifying the configuration of a distal end component and facilitating assembly of the distal end component. [Technical background of the invention and its problems] In recent years, medical and industrial endoscopes have been using solid-state imaging devices in their tip components.
CCD (charge coupled device), BBD (bucket brigade device)
By arranging devices such as the following, for example, an image inside a body cavity can be captured as an optical signal charge, and an endoscopic image can be displayed on a separate image display device for observation and medical tests, surgeries, etc. is proposed. In such an endoscope, the solid-state image sensor is a square or circular chip component having a light-receiving surface formed in the center and surrounded by a package. For example, in a direct-viewing endoscope, this chip-shaped solid-state imaging device must be held such that the light-receiving surface is substantially perpendicular to the axial direction of the insertion portion including the distal end component. In addition, an imaging optical system is disposed in front of the light receiving surface of the solid-state image sensor. Comparing this structure with an endoscope that uses an image fiber, in an endoscope that uses an image fiber, the image fiber is inserted through a channel member over almost the entire length of the insertion section and guided to the distal end. Since the channel member extends from the output end face of the image fiber, the tip portion can be constructed relatively easily by further extending the channel member and accommodating the imaging optical system within this extended channel. However, as mentioned above, endoscopes using solid-state imaging devices require a dedicated holder to hold the chip-shaped solid-state imaging device and a dedicated holder to hold the imaging optical system. There were problems such as the structure of the parts became complicated and the assembly work became complicated. In addition, electrical wiring to the electrode portion of the solid-state image sensor is troublesome. Furthermore, the tip component must be provided with a light guide fiber bundle or a light source element such as a light emitting diode as an illumination means. There was a problem in that the diameter was increased by the channel diameter occupied by the holder of the imaging optical system. As a conventional example of an endoscope having such a solid-state image sensor, the endoscope disclosed in Japanese Patent Application Laid-open No. 1983-46924 has a package that serves as a dedicated holder for the solid-state image sensor inside the cover. There is a device in which the package is fixed and a hole is made in the periphery of the package to guide a light guide fiber bundle or the like to the distal end surface.
However, this conventional example has the disadvantage that the imaging optical system must be fixed and held by other means. [Object of the Invention] The present invention has been made in view of the above-mentioned circumstances, and eliminates the need for a dedicated holder for holding the imaging optical system and the solid-state imaging device, and integrates the solid-state imaging device and the imaging optical system. It is an object of the present invention to provide an endoscope in which the configuration of the distal end component can be simplified by forming it as a component, the assembly work can be easily performed, and the diameter of the distal end component can be reduced. shall be. [Summary of the Invention] The present invention provides a lens body constituting at least a part of an observation optical system, and uses a holding part integrally molded with the lens part of the lens body to hold a solid-state image sensor, a light source element, or a light guide fiber bundle. It is designed to hold one of the lighting means and the like. [Embodiments of the Invention] The present invention will be described below with reference to illustrated embodiments. 1 to 3 are drawings relating to a first embodiment of the present invention, in which FIG. 1 is a cross-sectional view showing the distal end component of an endoscope according to the first embodiment of the present invention, and FIG.
The figure is a partially cutaway perspective view showing a lens body used in the first embodiment, and FIG. 3 is a perspective view showing a lens body of another shape. Although this embodiment will be explained using a direct-viewing endoscope, it can also be applied to a side-viewing endoscope.
Further, it may be applied to either a rigid endoscope or a flexible endoscope. This will be explained in detail below. In FIG. 1, reference numeral 1 indicates a distal end component of an endoscope, and this distal end component 1 is constructed at the distal end of an insertion section extending from an operation section (not shown). The portion extending from the operating section to the tip component 1 is covered with an outer tube 2 such as a rubber tube, and the terminal end of the outer tube 2 is attached to the rear end of the cap-like cover 3 of the tip component 1. ing. This cover 3 has an observation window 4 formed on the distal end side, and an illumination window 5 adjacent to this observation window 4. A cover lens 6 and a light distribution lens 7 are fitted into the observation window 4 and the illumination window 5, respectively. Further, the cover 3 has a concave groove 8 formed on the inner wall side, and a lens body 12 forming a part of the imaging optical system is fitted and fixed in the groove 8. The lens body 12 is formed by integrally molding an imaging optical system, such as a condenser lens 10, and a frame portion 12a that holds the solid-state image sensor 9 and the light guide fiber bundle 11. That is, this lens body 1
2 is formed into a shape as shown in FIG. 2, for example. The lens body 12 in FIG. 2 is made by integrally molding a synthetic resin such as plastic into a bottomed cylindrical shape with two colors, a transparent part and a colored part, and the condenser lens 10 is formed at the bottom part offset from the center. A transparent portion is formed. Further, the bottom outer edge and side portions of the lens body 12 form a colored portion formed as a frame portion 12a of the lens body 12 . This frame portion 12a holds the solid-state image sensor 9 as described later.
That is, the solid-state image sensor 9 is fixed and held on the opening-side end surface of the frame portion 12a of the lens body 12 by adhesive or other means. Of course, in this case, the light-receiving surface 9a of the solid-state image sensor 9 is attached so as to face the bottom of the lens body 12 , that is, the condenser lens 10. Furthermore, a light guide hole 13 is formed in the frame portion 12a of the lens body 12 adjacent to the condensing lens 10, and the light guide fiber bundle 11 guided from the operating section is formed in the light guide hole 13.
is inserted and retained. The output end face of this light guide fiber bundle 11 faces the light distribution lens 7 attached to the cover 3. Note that the lens body 12 may be provided with a guide hole for guiding a channel member such as an air/water channel or a forceps channel to the distal end side. According to the endoscope having the above configuration, the solid-state image sensor 9 is fitted into the frame 12a of the two-color integrally molded lens body 12 and held by adhesive or other means, and the solid-state image sensor 9 is held. By inserting the lens body 12 into the cover 3 and fitting it into the groove 8, the imaging optical system and the solid-state image sensor 9 can be loaded into the tip component 1 at the same time. And light guide fiber bundle 1
1 is inserted into the light guide hole 13 formed in the frame portion 12a of the lens body 12 , and the distal end component 1 is easily constructed by making it face the light distribution lens 7 of the cover 3. Therefore, there is no need to provide a dedicated holder for fixing the solid-state imaging device 9 to the tip component 1 and a dedicated holder for fixing the imaging optical system to the tip component 1. Therefore, the tube diameter of the tip component 1 is approximately determined by the outer diameter of the lens body 12 , and can be made smaller. Furthermore, the number of components of the tip component 1 is reduced, making assembly work easier. Here, the reason why the lens body 12 is a two-color integrally molded product made of synthetic resin and the edge of the condensing lens 10, that is, the frame 12a is colored, is that in addition to the light from the endoscopic image, light from the light guide fiber bundle 11 This is to prevent illumination light from entering the light receiving surface of the solid-state image sensor 9 as unnecessary light. In addition, as another embodiment, the lens body 12 is not made of an integrally molded product, but is made of, for example, a colored plastic cylinder that can cut off illumination light.
It may also be constructed by fitting a condensing lens 10 made of glass. Furthermore, as another example, the lens body 1
2 is integrally molded using glass as a material, and has a frame portion 12a.
A colored film may be formed on the surface of the portion corresponding to this by means such as vapor deposition. Further, the lens body 12 can also have a shape as shown in FIG. Lens body 12 in FIG.
A light guide insertion portion 12b is provided protruding from a frame portion 12a having a cylinder diameter approximately equal to the diameter of the condenser lens 10 in the outer circumferential direction, and a light guide hole 13 is formed in this light guide insertion portion 12b. There is. With such a lens body 12 , the tube diameter of the tip component 1 is determined by the diameter of the frame portion 12a and the light guide insertion portion 12b, and the solid-state image sensor 9 and the imaging optical system are integrated as an integral component. The configuration of the tip configuration section 1 can be simplified. Next, FIG. 4 shows a sectional view of an endoscope according to a second embodiment of the present invention. In FIG. 4, the same elements as in FIG. 1 are denoted by the same reference numerals. This second embodiment is
A light source element 14 such as a light emitting diode as a lighting means
This corresponds to a configuration using . This light source element 14 emits light using a power supply voltage from a power supply device (not shown) and irradiates the subject with the illumination light, and is attached to a lens body 12 configured similarly to the first embodiment. There is. That is, the lens body 12 is formed by integrally molding a transparent part and a colored part in two colors into a bottomed cylindrical shape of plastic, for example.
A transparent condensing lens 10 forming a part of the imaging optical system is formed at the center of the bottom, and a colored frame 12a is formed at the side and bottom peripheral parts. A solid-state image sensor 9 is integrally attached to this frame portion 12a. Furthermore, a light source attachment portion 12c is provided protruding from the frame portion 12a of the lens body 12 in the outer circumferential direction. The light source attachment part 12c is composed of a colored part and a transparent part.The transparent part constitutes the light distribution lens 7, and the colored part is configured to be fitted into a groove part 8 formed in the cover 3. The light distributing lens 7 has a concave surface with a curvature that matches the shape of the head of the light source element 14 on the rear side, and a convex surface with a smaller curvature than the concave surface on the rear side on the front side, so that the whole constitutes a concave lens. There is. The light source element 14 is attached so as to be pressed against the rear concave surface of the light distribution lens 7. However, the light source element 14 is the light distribution lens 7
It is also possible to form an integral structure by means of adhesion or the like. Furthermore, if the illumination light from the light source element 14 leaks to the solid-state image sensor 7, the light distribution lens 7 and the light source element 14 may be made to protrude to the position shown by the two-dot chain line in FIG. In this way, the solid-state image sensor 9 and the light source element 1
The lens body 12 holding the lens body 4 integrally is fitted into the groove 8 in the cover 3 and housed therein. This cover 3
In this case, the cover glass 6 is placed in the observation window 4 on the distal side.
A cover glass 15 is attached to each of the lighting windows 5, and an outer tube 2 is attached to the rear end surface. According to the endoscope configured as described above, the solid-state image sensor 9 and the light source element 14 can be integrally held in the integrally configured lens body 12 as at least a part of the imaging optical system, The configuration of the tip component 1 is simplified and the assembly work thereof is facilitated. Further, the tube diameter of the tip component 1 is approximately determined by the diameter of the lens body 12 , and since a dedicated holder such as the light source element 14 is not required, the diameter of the tip component 1 can be reduced. In this manner, the present invention simplifies the configuration of the tip component 1 by using, for example, the condenser lens 10, which forms at least a part of the imaging optical system, as a holder for the solid-state image sensor 9, etc. . Note that the lens body 12 may be configured to hold only the solid-state image sensor 9, or the solid-state image sensor 9 may be fixed by another means and the light source element 14 or the light guide fiber bundle 11 may be integrally held. It may be configured as follows. [Effects of the Invention] As explained above, according to the present invention, either the solid-state image sensor or the illumination means can be held by the lens body that forms at least a part of the imaging optical system, so that the tip component This has the effect of simplifying the configuration and making assembly work easier.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the distal end component of an endoscope according to a first embodiment of the present invention, FIG. 2 is a partially cutaway perspective view showing the shape of a lens body used in the first embodiment, and FIG.
The figure is a perspective view showing another shape of the lens body used in the first embodiment, and FIG. 4 is a sectional view showing the distal end component of the endoscope according to the second embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Tip component, 3...Cover, 8...Groove, 9...Solid-state image sensor, 10...Condenser lens,
DESCRIPTION OF SYMBOLS 11... Light guide fiber bundle, 12 ... Lens body, 13... Light guide hole, 14... Light source element.

Claims (1)

[Scope of Claims] 1. An endoscope in which a solid-state imaging device and an imaging optical system for forming an endoscopic image on a light-receiving surface of the solid-state imaging device are disposed in a distal end component, at least the imaging optical system A lens body constituting a part of the system is provided, and at least one of the solid-state image sensor and the illumination means is held by a holding part integrally formed from the outer edge of the lens part of the lens body. endoscope. 2. The lens body is made of synthetic resin such as plastics and is a two-color integrally molded body including a transparent part and a colored part, and the transparent part constitutes a lens part,
2. The endoscope according to claim 1, wherein the colored portion constitutes the holding portion, and the colored portion blocks illumination light from a solid-state image sensor. 3. The endoscope according to claim 1, wherein the lens body is integrally molded from glass, and a colored film is formed on the surface of the holding portion by vapor deposition means.