JPH01197716A - Enlargement photographing mechanism for electronic endoscope - Google Patents

Abstract

PURPOSE:To simultaneously pick up a wide area image of wide visibility angle and an enlarged image of a particular region by providing the hard point part of a scope with two pairs of an objective optical system and an image pick-up element having different enlargement ratio. CONSTITUTION:The objective optical system 3, a half mirror 5, a mirror 6, an oblong focal point lens 8 and image pick-up elements 9 and 10 are installed on the hard point part of the scope, and the two pairs of the objective optical systems are formed. The reflection light from an object 11 is focused by an objective lens system 3, and a wide area image is picked up from the reflected image by the image pick-up element 9 at the mirror 5. The light which permeated the mirror 5 passes through the oblong focal point lens 8 and is reflected by the mirror 6 and the enlarged image is picked up by the image pick-up element 10. Thus, the ordinally image plane 21 and the enlarged image plane 23 of the particular region are simultaneously displayed on a monitor image plane 20, and great effects which are not available by the conventional endoscope can be obtained.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) This invention relates to an electronic endoscope, and in particular to an electronic endoscope with different magnification ratios.
Enlarged photography a of an electronic endoscope that uses an IN optical system and an image sensor to simultaneously capture an enlarged image and a normal wide-area image
' Regarding JfI4.

(Conventional technology) Conventional endoscopes use an endoscope, which has an optical system with a fixed viewing angle and an image sensor at its tip, to introduce it into the inside of an object to be inspected, such as a structure or human body. , was photographing the subject.

Therefore, only one type of image with a constant magnification is obtained by photographing.

FIG. 5 shows a structural explanatory diagram of an imaging section at the distal end of a scope in such a conventional electronic endoscope.

An optical window 2, an objective lens 3, a mirror 6, and an image sensor 9 are housed in a rigid distal end portion 1 of an endoscope.

The image of the subject 11 enters through the optical window 2 and passes through the objective lens 3.
The light is focused by the mirror 6 and reflected by the mirror 6, and an image is formed on the surface of the image sensor 9 and photographed. The original image signal photographed by the image sensor 9 is transmitted through a signal line (not shown), processed in the main unit of the endoscope (not shown), and displayed as an image on, for example, a color monitor 'rv.

By the way, the larger the image magnification, the more detailed the object can be seen, which is suitable for precise observation.

Further, the wider the viewing angle, the more the shape of the subject can be seen, which is advantageous for observing the entire image.

(Problem to be solved by the invention) However, when imaging using the same optical system such as an objective lens, the viewing angle and magnification are inversely proportional, so the viewing angle must be widened to make it easier to grasp the overall image. If the focus is off, it becomes difficult to see the details of the subject. Also, the interest of the subject
If the area is expanded to enable detailed observation, the viewing angle becomes narrower, making it difficult to grasp the overall image.

This invention was made to solve the conflicting problem of viewing angle and magnification in conventional endoscopes. The object of the present invention is to provide an electronic endoscope having an enlarged photographing mechanism capable of photographing two types of images at the same time.

[Configuration of the Invention (Means for Solving the Problem) In order to achieve such an object, the electronic endoscope according to the present invention has two sets of different magnifications at the distal end of the endoscope. The present invention is characterized by having an enlarged photographing mechanism configured to simultaneously photograph an enlarged image and a wide-area image by providing an objective optical system and an imaging element corresponding to each of the two sets of objective optical systems.

(Function) Enlarged photographing 1E1ti of electronic endoscope with such a configuration
According to II, two types of optical systems with different magnification ratios and corresponding image sensors are used to simultaneously capture two types of images of the same subject with different magnification ratios: a wide-area image with a wide viewing angle, and a magnification ratio image. This allows for a large magnification of the image, making it easier to observe both the general overview and detailed regions of interest.

(Embodiments) Below, embodiments of the magnifying imaging mechanism for an electronic endoscope according to the present invention will be shown and explained in detail based on the drawings.

FIG. 1 shows the configuration of an embodiment in which two sets of objective optical systems with different magnifications are disposed at the distal end of an endoscope using half mirrors.

An optical window 2 through which an image of a subject 11 enters is provided inside a rigid distal end portion 1 of the endoscope, and an objective lens system 3 is provided inside the optical window 2. The objective lens system 3 is usually a combination lens consisting of a convex lens and a concave lens. Objective lens system 3
There is a half mirror 5 that allows approximately half of the optical image that has passed through the mirror to pass therethrough and reflects the remaining portion approximately at right angles. Further, the light that has passed through the half mirror 5 passes through the long focal length lens 8 and is then reflected by the mirror 6, forming an optical image on the image pickup device 10 on the right side of FIG.

Next, the operation of the embodiment shown in FIG. 1 will be described.

The light reflected by the object 11 passes through the optical window 2 and reaches the objective lens system 3. The optical image of the object that has passed through the objective lens system 3 passes approximately half of it through the half mirror 5, and the rest is reflected, converging and focusing the optical image of the object onto the surface of the image sensor 9 on the first left m1. Image this II
The image element 9 captures a wide-angle portrait.

On the other hand, approximately half of the rays passing through the half mirror 5 are reflected by the rear mirror 6 and enter the long focal length lens 8. The long focus lens 8 focuses this reflected optical image of the object onto the surface of the tQ image element 10 on the right side of FIG.
The image is formed, and an enlarged image is captured by the image sensor 10.

Furthermore, it is necessary to set the focal point "r;distance" of the long focal length lens 8 so that the optimum photographing distances for the enlarged image and the wide-angle image are approximately equal.

Now, as shown in FIG. 4, if the focal length of the objective lens system 3 is fO1 and the focal length of the focal lens 8 is f8, then
The focal length, Wfl, of the magnifying image lens system composed of the objective lens system 3 and the long focal length lens 8 is ;fl=(fo・f8
) / (fo + f8 - d) (where d is the distance on the optical axis between the objective lens system 3 and the long focal length lens 8).

Furthermore, if the optimal shooting distance is a (for example, 15 m+),
Image-side principal point of objective lens system 3 ] 10 and the distance between image sensor 9 (image distance of wide-angle image) If the distance to the image sensor 10 (image distance of the enlarged image) is bl; 1/a+1/bo=1/f.

It is necessary to construct a lens system that satisfies 1/a+1/bl=1/fl.

The image magnifications of the wide-angle image and enlarged image are respectively expressed as: bo/a and bl/a, and the magnification ratio is expressed as: (bl/a) / (bO/a) = bl/bO and is set to about 2 to 10 times.

In this way, both enlarged and wide-angle original images of the subject captured by the left and right image sensors 9 and 10 are transmitted as original image signals through a plurality of signal lines (not shown), and are subjected to signal processing in the main unit of the endoscope (not shown). The image is then displayed on, for example, a color monitor TV.

An example of this image display is shown in FIG.

On the right side of the monitor screen 20 is a normal screen 21 which is a wide area image.
is displayed, and an enlarged image of the region of interest in the center of this normal screen 21 is enlarged and displayed on the enlarged screen 23 on the left side of FIG.

In this way, by displaying the wide-area normal screen and the enlarged screen of the region of interest side by side on the same color monitor TV, etc., it becomes possible to simultaneously observe the entire image and the enlarged image of the central and central areas. The effect will be huge.

Of course, it is not necessary to display two types of images in parallel in this way, but it is also possible to display only one of them according to the viewer's request, such as by operating a switch or manually using a key, or by using multiple display devices to magnify each image differently. It is also possible to display an image of the ratio.

Furthermore, depending on how two types of images with different magnifications are displayed, the signal processing inside the endoscope main body (not shown) and the method of holding each image data also differ.

If two types of images are to be displayed at the same time as shown in Figure 2, the endoscope itself must be configured to have two systems of image memory, etc. that process, store, hold, and output both image data simultaneously. There is a need to. If only one of the images is to be switched and displayed according to the operator's specifications, the image memory etc. in the endoscope body should be used in only one system, and the two images sent from the two sets of image sensors should be used. It may be configured such that the seed original signal is selected and taken in at the entrance of the main body.

On the other hand, FIG. 3 is a structural explanatory diagram of a second embodiment configuration in which the enlarged photographing mechanism of the present invention is applied to a side-viewing endoscope.

Compared to the configuration of the embodiment shown in FIG. 1, the half mirror 5 at the rear stage of the mirror 6 faces in the opposite direction, and the optical image of the object is distributed to the lower left and left side of FIG. 3. Furthermore, a short focal length lens 7 is interposed just in front of the wide-angle imaging system 9. The other configurations and operations are substantially the same as those in FIG. 1, so their explanations will be omitted.

In this way, the magnifying photographing mechanism of the electronic endoscope according to the present invention can be applied to a side-viewing endoscope.

Note that this invention is not limited to the configurations of each of the embodiments described above, and can be implemented by various B types by making appropriate changes.

For example, the angle and arrangement of each lens, half mirror, etc. can take various forms depending on the shape of the scope, etc. Also, if the dimensions of the scope allow, two optical windows can be installed to provide completely separate optical and It is also possible to configure the imaging system to take 2N images.

[Effects of the Invention] As explained above in detail, by applying the magnification photographing mechanism of the electronic endoscope according to the present invention, two types of images with different magnification ratios can be obtained simultaneously! With one image, you can simultaneously obtain a wide-area image with a wide viewing angle and a detailed enlarged image of the region of interest, making it easy to see the entire image in a large size and observe the region of interest in detail. You will be able to achieve a huge effect that has never been seen before.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the structure of the rigid tip portion of a direct-viewing endoscope according to an embodiment of the electronic endoscope to which the magnifying TFI shadow mechanism of the electronic endoscope according to the present invention is applied, and FIG. A diagram showing an example of displaying a seed image, FIG. 3 is an explanatory diagram of the structure of the rigid tip portion of a side-viewing endoscope that is a second embodiment of the present invention, and FIG. FIG. 5 is an explanatory diagram of the optical system of the rigid distal end of an endoscope. FIG. 5 is an explanatory diagram of the structure of the rigid distal end of a conventional endoscope.

Claims (1)

[Claims] (1) Two sets of objective optical systems with different magnification ratios and an image sensor corresponding to each of the two sets of objective optical systems are provided at the distal end of the endoscope to generate enlarged images and wide-area images. A magnifying imaging mechanism for an electronic endoscope, characterized in that it is configured to simultaneously take images.