JPH0228329B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an endoscope, and particularly to an endoscope that uses a solid-state image pickup device to extract an image of a subject as an electrical signal and guide it to an image display device such as a cathode ray tube to reproduce the image. .

Endoscopes that use solid-state imaging devices, such as charge transfer devices (CCDs) or bucket brigade devices (BBDs), are more economical and smaller than conventional endoscopes that use optical fibers as image guides. It is considered promising because it has many other excellent features.

However, from the standpoint of miniaturization, this type of conventional endoscope cannot be said to leave room for structural improvement. For example, when inserting an endoscope head into the stomach, it is desirable to make the endoscope head as small as possible to avoid discomfort for the patient, and in this respect, conventional proposals have not always been satisfactory. It wasn't something I could do.

In direct-view endoscopes using conventional solid-state image sensors, the captured image in which the pixels of the solid-state image sensor are arranged is arranged perpendicularly to the longitudinal direction of the sheath in the head of the endoscope, and one or more The light guide, water supply, air supply hole, forceps/treatment instrument guide, etc. pass through the side of the solid-state imaging device package and extend to the front end surface of the sheath. Since the package of the solid-state image sensing device itself has a relatively large size compared to its effective captured image, a structure in which a light guide or the like passes through the outside of the package requires a considerably large outer diameter of the sheath.

Accordingly, an object of the present invention is to provide an endoscope using a solid-state imaging device having a small head with a small outer diameter.

According to the invention, this object is achieved by an endoscope as follows. In other words, this endoscope includes a sheath that is generally cylindrical as a whole, an imaging optical system whose optical axis is arranged substantially parallel to the longitudinal direction of the sheath, and a captured image that is substantially perpendicular to the optical axis. and a solid-state imaging device disposed in the housing, the solid-state imaging device having a generally cylindrical package supported inside the sheath, and a peripheral edge of the package communicating from one end surface to the other end surface. An aperture is provided through which the light guide terminates at the end surface of the sheath.

With this configuration, the endoscope according to the present invention has at least the light guide incorporated into the package of the solid-state image sensor and disposed close to the longitudinal axis of the sheath, so that the endoscope head can be easily moved. Not only does this reduce the diameter of the area, but it also has the effect of uniformly illuminating the subject using the light guide.

According to an aspect of the present invention, a plurality of such openings may be arranged, and the light guide may be passed through at least two of these openings. This allows the diameter of each light guide required to maintain a constant illuminance of the subject to be small, making it possible to further reduce the outer diameter of the head and making uniform illumination of the subject even more effective. can be obtained. Note that throughout this specification, "opening"
This term is used to include not only those whose cross-sectional shape is completely closed, but also those whose cross-sectional shape is open, that is, notches.

Hereinafter, the present invention will be explained in detail by showing preferred embodiments. Note that in this specification, the term "endoscope" includes not only an endoscope inserted into a body cavity of a living body but also an industrial endoscope inserted into a cavity of an apparatus.

FIG. 1 is a side cross-sectional view showing the main part configuration of an endoscope head according to the present invention. In FIG. 1, the solid-state image pickup device is indicated by 1, and a large number of pixels 3 are arranged on a chip 2 to form a captured image, which is supported by a package 4 made of, for example, ceramic. A plurality of small holes 5 and notches 5a are provided on the peripheral edge of the package 4 in parallel with the longitudinal direction of the sheath portion 8 as shown in the figure, and a large number of optics are inserted into these small holes 5 and notches 5a. A light guide 6 made of fiber fiber and an air/water pipe 7 are passed through. The tip of the light guide 6 is glued to a glass window 9 provided in the forehead of the sheath 8, and the light guided by the light guide 6 is irradiated onto a subject (not shown) and A lens 10 connects the image of the subject through a glass window 11 to three pig cells of a solid-state image pickup device, and electrical signals obtained from this device in response to the light from the image point are sent to an image display on a cathode ray tube or the like using a conductor 12. The image is guided to a device (not shown), which reproduces the image of the subject so that it can be observed.

FIG. 2 is a cross-sectional view taken along the dashed line AA in FIG. 1, and the present invention will become clearer by referring to this. In FIG. 2, the same reference numbers as in FIG. 1 refer to the same elements as in FIG.

Referring to FIG. 2, it can be seen that the sheath 8 has a cylindrical shape. The sheath part 8 is made of plastic,
Alternatively, it may be made of metal coated with plastic, rubber, or the like, and its shape is preferably approximately cylindrical as a whole from the viewpoint of ease of insertion into the body cavity of the endoscope head.

On the other hand, the shape of the package 4 is generally flat and substantially cylindrical in accordance with the sheath portion 8 in the present invention. Such a shape is advantageous in terms of space efficiency in terms of miniaturization of the endoscope. In other words, it is possible to increase the effective area of the image sensor relative to the conventional rectangular package.

As shown in FIG. 2, in the embodiment of the endoscope according to the present invention, a plurality of light guides 6 are connected to a cylindrical package 4.
are distributed and stored around the periphery of the In order to avoid complicating the diagram in FIG. 1, only one of the plurality of light guides 6, which are branched almost equally from a large number of optical fibers included in the light guide bundle 13, is connected to the small hole 5. The other light guides 6 are not shown in the middle, but as can be seen from FIG.
It terminates in correspondence with another window similar to window 9 provided in .

By distributing a plurality of light guides 6 around the periphery of the package 4 in this way, the light from each light guide 6 can be focused and irradiated onto the subject, making illumination uniform. It can be achieved. This will be described in more detail using FIG.

FIG. 3 is an enlarged view of the glass window 9 in FIG. 1. As is clear from FIG. 3, the structure of the glass window 9 and the glass window 9 of the light guide 6
The mounting form of the light guide 6 is adapted to provide directivity of the light from the light guide 6. That is, the inner surface 9a of the window 9 is inclined as shown in the figure, so that the light emitted from the light guide 6, which is glued perpendicularly to this surface with a suitable transparent adhesive, is directed in the direction of the arrow 15 in the figure. being done. This direction is objective lens 1
The other light guides 6 are connected to the corresponding windows 9 in the same way, and the illumination light exiting each light guide 6 is directed toward a certain point on the optical axis of the objective lens 10. They intersect at a point, that is, near the focal point of the objective lens 10. Therefore, the object to be examined near the optical axis is illuminated more effectively and uniformly by condensing the illumination light from the plurality of light guides 6.

Continuing the explanation by returning to FIGS. 1 and 2 again, in the embodiment, the periphery of the package 4 is provided with air supply and
An example is shown in which a cutout 5a for the water pipe 7 is provided and the air/water pipe 7 is passed through it.
This only shows that such a configuration is possible if necessary, and if necessary, these small holes 5 or notches 5a provided in the conduit package 4 for other elements such as forceps or treatment tools etc.
It may be stored in

Further, in this embodiment, the air/water supply pipe 7 is located near the center of the light guide bundle 13, and is surrounded by optical fibers concentrically. A plurality of light guides 6 are formed by branching almost equally. This is because the illumination of the subject by the light guide 6 involves the generation of a considerable amount of heat.
In order to prevent the optical fibers passing through the bundle 13 from overheating and causing thermal damage to the solid-state imaging device 1 located near them, the optical fibers passing through the bundle 13 are cooled by liquid or gas passing through the water/air supply pipe 7. It is something.

Furthermore, according to this technique, even if an illumination beam having a larger amplitude than currently used is used, the living body being examined will not be damaged or suffer due to heat.

Although one embodiment of the present invention has been described below, other modifications are also possible. For example, the number of light guides 6 does not necessarily have to be plural, and may be one. In addition, in the above embodiment, the light guide 6 is attached to the package cage 4.
Although a small hole 5 is provided for this purpose, a cutout similar to the cutout 5a may be provided instead. Furthermore, other variations are possible without departing from the spirit of the invention.

By configuring the endoscope according to the present invention as described above, the light guide, water supply/air supply tube, and/or forceps/treatment instrument guide path pass through the package itself of the solid-state image sensor, so that the endoscope head The unit can be made smaller. Furthermore, since the light guide is arranged close to the optical axis of the imaging system, the subject can be illuminated uniformly, and this is even more effective in embodiments in which a plurality of light guides are distributed.

[Brief explanation of drawings]

FIG. 1 is a side cross-sectional view showing the main part configuration of an endoscope head according to the present invention, and FIG. 2 is a dashed-dotted line A--
3 is an enlarged view of the glass window portion in FIG. 1. Explanation of symbols of main parts, solid-state image sensor...1,
Package cage...4, Opening...5, 5a, Light guide...6.

Claims (1)

[Scope of Claims] 1. An endoscope including: a generally cylindrical sheath; an imaging optical system disposed in the sheath; and a solid-state image sensor disposed together with the imaging optical system, wherein the solid state includes: The imaging device has a generally cylindrical package supported inside the sheath, and a peripheral edge of the package is provided with an opening that communicates from one end surface of the package to the other end surface of the package, and the endoscope includes a light guide that passes through the opening and terminates at the sheath portion, a plurality of the openings are provided, and a light guide passes through at least two of the plurality of openings, respectively. endoscope. 2. In the endoscope according to claim 1, the light guide terminates at the end surface of the sheath so that the light exiting the light guide approaches the optical axis of the imaging optical system. Characteristic endoscope. 3. The endoscope according to claim 1, wherein the light guide includes optical fibers that are almost equally branched from a single light guide bundle that includes a large number of optical fibers. endoscope.