JPS638622A - Electronic endoscope device - Google Patents

Abstract

PURPOSE:To obtain an image moving or CCD leading-in optical system which does not cause the deterioration of a picture quality, by arranging opposingly an end face of a small area, and an end face of a large area, on the focal plane of an objective lens, and a solid-state image pickup element surface, respectively, so that the respective end faces intersect perpendicular to the main optical axis of an image pickup optical system. CONSTITUTION:An objective lens 1, a diaphragm 2, an optical fiber bundle 3 in which an input end face 3a is arranged coincidently on the rear focal plane of the objective lens 1, and a CCD4 arranged so as to be opposed correctly to the output end face 3b of an optical fiber bundle 3 are aligned and arranged on a main optical axis '0', respectively. The necessary number of unit optical fibers 3' having a cheeper in the longitudinal direction are bundled, and constituted so that the area (size) of each end face becomes the area (size) of the input end face 3a and the output end face 3b, respectively, and the cheeper of the unit optical fiber 3' is set to conform with the condition of the area constitution. According to such a constitution, the photographed image of a part to be inspected, which is formed on the focal plane (input end face 3a) by the objective lens 1 is enlarged and moved to the output end face 3b by the optical fiber bundle 3 and made incident on the CCD4.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to an electronic endoscope device used in the field of medical diagnosis, and particularly to an optical fiber bundle provided at the distal end of a scope. This invention relates to the improvement of electronic endoscope devices that perform the following tasks.

(Prior art) In an electronic endoscope device that is mounted on a rectangular screen, the optical image that passes through the diaphragm placed immediately after the objective (eye image) lens is, for example, as shown in Fig. 4 (a). As shown, a solid-state image carrier (hereinafter referred to as C
(abbreviated as OD) or the same figure (b)
As shown in Figure 2, a thin optical fiber bundle is used to bend the optical path, and the output end face of the fiber bundle is formed into a diagonal cross section to expand the output surface area, and the COD is placed facing there. Necessary for insurance.

(Problems to be Solved by the Invention) However, in the case of the former method, there is a drawback that it is necessary to use an erecting optical system such as a roof prism because the image is reversed horizontally due to the inverse q In the case of this method, ``unevenness in the amount of light'' inevitably occurs between the individual optical fins and fibers, and distortion occurs in the image, so the device itself becomes complicated and requires a means to correct this. , which has the disadvantage of causing a significant deterioration of image quality. Therefore, a solution to these drawbacks is strongly desired.

The present invention has been made in view of this situation, and in the latter type, image movement or C
It is an object of the present invention to provide a novel electronic endoscope device equipped with a CD introduction optical system.

[Structure of the invention] (Means for solving and overcoming the problems) The structure of the present invention for achieving this object is to set the area of one end surface of the optical fiber bundle small to guide the object image onto the solid-state FJL element. In addition, the area of the other end face is set to be large, and the end face with the small area is set at the focal plane of the objective lens, and the end face with the large area is set at the surface of the solid-state image sensor, so that each end face is the main part of the image carrying optical system. They are arranged opposite to each other so as to be perpendicular to the optical axis.

(Function) The function of the present invention based on this configuration is to form an image on the focal plane by making the optical fiber bundle directly face the focal plane of the objective lens and the CCD plane while giving the optical fiber bundle the effect of enlarging the optical image. The point is that the optical image obtained is guided onto the COD surface which has a large photosensitive area.

(Example) The present invention will be described in detail below based on an example shown in the drawings.
The meaning of the edict "directly opposed" used in this explanation is the purpose (
This means that the target plane intersects perpendicularly to the principal optical axis.

FIG. 1 shows an example of an electronic endoscope device according to the present invention.
This is a schematic optical path diagram, in which O is the main optical axis that coincides with the axis of the tip of the endoscope, 1 is the objective lens, 2 is the diaphragm, and 3 is the input end surface 3a of which is on the rear focal plane of the objective lens 1. an optical fiber bundle 4 arranged in accordance with the optical fiber bundle 3;
The CODs are disposed directly facing the output end face 3b of the CODs, and are aligned on the main optical axis O.

Note that the end face structure of the optical fiber bundle 3 is similar to that of the input end face 3.
The area (size) of a is the same as or smaller than the area (size) of the rear focal plane of the one-object lens 1, and the area (size) of the output end surface 3b is the effective area (size) of the COD. The area of the input end surface 3a is set to be smaller than the area of the output end surface 3b. In this case, in order to make it easier to bundle the fiber bundle, the range 1 in the figure is bundled with its expanded area,
Connected to COD/l.

Now, to give an example of the construction method, as shown in Fig. 2, the required number of unit optical fibers 3- with a taper in the longitudinal direction are bundled, and the area (size) of each end face of h is They are configured to have the same area (size) as the input end face 3a and the output end face 3b described above, respectively. In this case, it goes without saying that the taper of the unit optical fiber 3- is set to meet the conditions of this area configuration.

With such a configuration, the decoy image of the subject formed on the focal plane (input end surface 3a) by the objective lens 1 moves while being enlarged to the output end surface 3b by the optical fiber bundle 3, and is moved to the output end surface 3b by the optical fiber bundle 3. It will be incident on .

Figure 3 shows another embodiment of the present invention, and the same numbers and marks 8 as in Figure 1 are the same as in Figure 1, so the details are omitted. The main optical axis is bent in a direction perpendicular to the entrance direction, and 13 is an optical fiber bundle bent and arranged along this main optical axis O'.
', the equivalent basic channel is constructed in the same way as in the example shown in the first figure.

In this embodiment, the CCD 4 is installed parallel to the optical axis up to the focal plane of the objective lens 1 at the maximum cross section of the scope. Therefore, in this case, a large area CC
There are advantages to using D.

Although the two embodiments have been described above, the present invention is not limited thereto, and can be modified in various ways without departing from the spirit thereof.

For example, each unit optical fiber may have a circular cross section,
It may also have other shapes such as a rectangular cross section.

[Effects of the Invention] As described above, when the present invention is used, an optical system for image movement or CCD introduction without deterioration in image quality can be obtained in an electronic endoscope device using an optical fiber bundle.

[Brief explanation of drawings]

FIG. 1 is a schematic optical path diagram showing an example of an electronic endoscope device according to the present invention, FIG. 2 is a schematic diagram showing an example of the structure of individual unit optical fibers, and FIG. 3 is another embodiment of the present invention. Schematic optical path diagrams illustrating examples, FIGS. 4(a) and 4(b) are explanatory diagrams for explaining conventional strategic optical path diagrams. 0.0-...Principal optical axis, 1...Objective lens, 2...
Aperture, 3... Optical fiber bundle, 3a... Input end surface, 3
b...Output end face, 3-...Unit optical fiber, 4...
・CCD, 13...optical fiber bundle. Agent Patent Attorney Rule Yudo Chikaten
Norio Ogo Figure 2

Claims (4)

[Claims] (1) In an electronic endoscope device in which a subject image is guided onto a solid-state image sensor through an optical fiber bundle, the area of one end surface of the optical fiber bundle is set small, and the area of the other end surface is set large. The small-area end face is at the focal plane of the objective lens, and the large-area end face is at the solid-state imaging device surface, so that each end face intersects perpendicularly to the principal optical axis of the imaging optical system. An electronic endoscope device characterized by being arranged opposite to each other. (2) The input area of the small-area end face is an area less than or equal to the light-receiving area at the focal plane of the objective lens, and the output area of the large-area end face is an area less than or equal to the effective area of the solid-state image sensor. The electronic endoscope device according to item 1. (3) The unit optical fibers constituting the optical fiber bundle are:
The electronic endoscope device according to claim 1 or 2, which is an optical fiber tapered in the longitudinal direction. (4) Claims 1 to 3, wherein the solid-state image sensor is disposed at a position within a cross section parallel to the axis of the endoscope at the maximum diameter portion of the scope.
The electronic endoscope device according to any one of paragraphs.