JPH0324512A - Electronic endoscope device - Google Patents

Abstract

PURPOSE:To enable visual field conversion without making the structure of a scope tip part complex by providing a half-mirror, a 1st photodetecting element which photodetects incident light, a 2nd photodetecting element which photodetects light transmitted through the half-mirror, and a slecting means in an endoscope. CONSTITUTION:A scope part 1 is provided with the half-mirror 7, and a CCD (1st photodetecting element ) 9 where the incident light refracted by the half- mirror 7 is made incident is set longer in the optical path length from an objective 5 than a CCD (2nd photodetecting element) 11 where the incident light transmitted through the half-mirror 7 is made incident. Then when one video signal is selected with a changeover switch 4, a video signal having a different visual field is obtained because the CCD 9 and CCD 11 are different in optical path length. Consequently, the visual field can be converted without making the structure of the scope tip part complex.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to an electronic endoscope device that obtains a video signal using a light-receiving element provided inside a scope, and particularly relates to an electronic endoscope device that obtains a video signal using a light-receiving element provided inside a scope. This paper relates to the improvement of the 'R conversion mechanism of the field of view. (Prior art) In this type of electronic endoscope, the objective lens focuses the reflected light from the observation target area onto the light-receiving surface of the light-receiving element, and this objective lens and light-receiving element If the surface is fixed, the observable distance, that is, the distance to the observation target part that can be focused on the light-receiving surface, and the viewing angle, that is, the extent of the spatial area that can be observed (hereinafter collectively referred to as the field of view) are limited. ．． Conventionally, the objective lens was replaced, or the objective lens was composed of multiple lenses, and the mutual distance between them was made variable.
By manipulating this, I was able to change my field of view. (Problems to be Solved by the Invention) However, replacing the objective lens requires complicated work such as once removing the scope, replacing the lens, and then reinserting it.Furthermore, in the case of multiple movable lenses, The lens movement mechanism is complicated due to the use of cams, etc., and the variator that provides a variable magnification effect when changing the field of view and the compensator that maintains focus must also perform complex functions, which is economically disadvantageous. At the tip of the scope, where various structures such as cleaning mechanisms and cleaning mechanisms are concentrated, a smaller diameter is desired.
This is also unfavorable in terms of device design. The present invention has been made in consideration of such problems in the prior art, and an object of the present invention is to provide an electronic endoscope that can change the field of view without complicating the arrangement of the vessel at the distal end of the scope. ．． [TF4 of the invention] (Means for solving the problem) In order to achieve the above object, the electronic endoscope according to the present invention refracts a part of the incident light that enters the endoscope. At the same time, a half mirror that transmits a part of the incident light, a first light receiving element that receives the incident light refracted by the half mirror, and a half mirror that has a different optical path length from the first light receiving element and that The object of the present invention is to include a second light receiving element that receives the incident light transmitted by the mirror, and a selection means that selects one of the signals obtained by each of the first light receiving element and the second light receiving element. It is said that

(Function) In the above-mentioned horizontal formation, among the incident light that enters the endoscope through the objective lens, the incident light that is refracted by the half mirror is transferred to the light receiving surface parallel to the long plane direction of the endoscope. The first light-receiving element is arranged to have a light-receiving surface perpendicular to the longitudinal direction of the endoscope, and the incident light is transmitted by a half mirror. When the selection means selects one of the video signals made incident on the second light receiving element and obtained by each of the first light receiving element and the second light receiving element, the first light receiving element and the second light receiving element are connected to each other. Since the optical path lengths are different, video signals with different fields of view can be obtained.

In other words, the field of view can be converted even if the structure of the tip of the scope is not complicated. (Embodiment) An embodiment of the electronic endoscope apparatus according to the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 is a diagram illustrating main parts provided in the scope section (endoscope, part) 1 and the device main body 3 of the electronic endoscope device. In this figure, the scope section 1 includes a half mirror 7 that refracts a portion of the incident light that enters the scope section 1 through the objective lens 5 by 90 degrees and transmits a portion of this incident light. has been done. Furthermore, a CCD (first light receiving element) 9 having a light receiving surface parallel to the longitudinal direction of the scope section 1 and into which the incident light refracted by the half mirror 7 is incident, and a CCD (first light receiving element) 9 having a light receiving surface parallel to the longitudinal direction of the scope section 1 and a CCD (first light receiving element) 9 having a light receiving surface parallel to the longitudinal direction of the scope section 1 and into which the incident light refracted by the half mirror 7 is incident. A CCD that has a light-receiving surface and receives the incident light that has passed through the half mirror 7.
(Second light receiving element) 11 is installed inside the scope section 1, with the optical path length from the objective lens 5 set to be longer in the CCD II than in the CCD 9.

Therefore, as shown in FIG. 2, the light image focused on the CCD 9 is a close-up narrow-angle image 1
3, and the light image focused on the CCD II becomes a distant wide-angle image 15 at a position farther from the objective lens 5 than the close-up narrow-angle image 13. In addition, in this FIG. 2, the objective lens 5 is simply shown as a single convex lens, and the CCD 9
Only the light rays for the light image focused on the center of the light-receiving surface of the CCD 11 are shown. Further, the apparatus main body 3 is provided with a changeover switch 17 as a selection means for selecting one of the image signals obtained by each of the CCDs 9 and 11. In order to display images based on the electrical signals obtained in the above, a camera control unit (hereinafter referred to as CCLJ) 19 is used as a signal processing/display system to convert the electrical signals into NTSC signals. , A/D converter 21, frame memory 23 for obtaining still images, D/A converter 2
5. Monitors 27, etc. are connected in order. Note that the switching switch 17 does not necessarily need to be provided at the front stage of the CCU 19, but at the rear stage of the CCLJ 19 or the A/D converter 21. The configuration may be such that it is provided after either the frame memory 23 or the D/A converter 25. Note that a command switch is provided on the hand operation section (not shown) of the scope section 1 or on the main body 3 of the device, and when either the distant wide-angle image 15 or the close-up narrow-angle image 13 is selected,
In conjunction with each of these selections, the changeover switch 17 is operated to select contact a or contact b. In such a configuration, the changeover switch 17
is selected, the distant narrow-angle image 15 focused on the CCD 9 is sent to the signal processing/display system, and when contact b is selected with the changeover switch 17, the close-up wide-angle image focused on the CCD II is sent to the signal processing/display system. Image 13 is sent to the signal processing/display system. Therefore, the changeover switch 17 selects either of the electric signals obtained from the CCD 9 and the CCD 11.
When selected, an image with a different field of view is displayed on the monitor 27, so it is possible to easily change the field of view without complicating the tip of the scope with a lens movement mis or a variable magnification mechanism. ．． [Effects of the Invention] As explained above, in the electronic endoscope device according to the present invention, there is a half beam that refracts a part of the incident light that enters the endoscope scope and transmits a part of the incident light. a mirror, a first light-receiving element that receives the incident light refracted by the half mirror, and a first light-receiving element that has a different optical path length from the first light-receiving element and receives the incident light that has passed through the half mirror. 2 light receiving elements, and selection means for selecting one of the signals obtained by each of the first light receiving element and the second light receiving element. Although this configuration minimizes the complexity of the vessel arrangement at the tip of the scope, it is possible to reduce the amount of incident light that is refracted by the nose mirror out of the incident light that enters the endoscope through the objective lens. making the incident light incident on the first light receiving element and passing through the half mirror enter on the second light receiving element;
When one of the video signals obtained by the first light receiving element and the second light receiving element is selected by the selection means, it is easy to You can convert the field of view to .

[Brief explanation of drawings]

FIG. 1 is a horizontal block diagram of essential parts of an embodiment of an electronic endoscope apparatus according to the present invention, and FIG. 2 is an explanatory diagram showing an embodiment of the path of a light beam incident on a light receiving surface of a light receiving element. 7 ・Half mirror 9.11...CCD13...
Close-up wide-angle image 15, distant narrow-angle image 17, selector switch

Claims (1)

[Claims] (1) A half mirror that refracts a portion of the incident light that enters the endoscope scope and transmits a portion of the incident light, and a first light receiver that receives the incident light that has been refracted by the half mirror. a second light receiving element that has a different optical path length from the first light receiving element and receives the incident light transmitted by the half mirror, the first light receiving element and the second light receiving element;
An electronic endoscope apparatus comprising: a selection means for selecting one of the signals obtained by each of the light receiving elements.