JPS61255318A - Endoscope device - Google Patents

Abstract

PURPOSE:To obtain an endoscope device which can pick up an object with high resolution without enlarging the diameter of its endoscope, by providing a means which irradiates spot light upon the object while making two-dimensional scanning and another means which photoelectrically converts the reflecting light from the object. CONSTITUTION:Since spot light made incident on a 'SELFOC(R)' fiber lens 18 is projected on an object 20 after it is enlarged in accordance with a necessary light distributing angle by means of an enlarging lens 16 at the front end of an endoscope and the object is illuminated, the spot light scans the object 20 in accordance with the raster scan of an electron beam. Reflecting light from the object 20 is photoelectrically converted by a photoreceptor element 12 contained in the front end of the endoscope 12 and only the reflecting light from the part, upon which the spot light is irradiated, is made incident on the photoreceptor element 12. Since the spot light is raster-scanned, however, the two-dimensional distribution information of the reflecting intensity on the object 20 is outputted in time series from the photoreceptor element 12. Therefore, the object is practically scanned for image pickup even when the photoreceptor element 12 does not make image pickup scan, namely, even when only one picture element exists.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an endoscope apparatus, and particularly to an endoscope apparatus for imaging a subject.

[Prior Art] As shown in, for example, Japanese Utility Model Publication No. 59-31212, a conventional technique involves inserting a solid-state image pickup device into the tip of an endoscope instead of providing an image guide inside the endoscope, and detecting the subject. There is an endoscope device that captures an image and supplies the image signal to an external monitor via the endoscope for display. The performance of such an endoscope device depends on the solid-state image sensor. In particular, it is desired that the number of pixels be large. However, since endoscopes are often inserted into narrow tubular members or into body cavities, there is also a situation in which the diameter of the end cannot be increased.

[Problem to be Solved by the Invention 1] As described above, in the conventional technology, conflicting demands such as a large number of pixels and a small size have been imposed on the solid-state image pickup device built into the tip of the endoscope. The present invention was made in view of these problems, and it is an object of the present invention to provide an endoscope device that can image a subject at high resolution without increasing the diameter of the endoscope.

[Means for Solving the Problems] According to the endoscope apparatus according to the present invention, a means for irradiating a subject with spot light while scanning the subject in two dimensions, and a means for photoelectrically converting light reflected from the subject are provided. There is.

[Effect] This? In c2, the subject is illuminated while scanning the spot light two-dimensionally, the light reflected from the subject is photoelectrically converted by the light receiving element, and the photoelectric change detection power is written in the storage means in correspondence with the scanning of the spot light, thereby illuminating the subject. A two-dimensional distribution of reflection intensity on the subject, that is, an optical image, similar to that obtained when an image is captured using an image sensor is obtained.

[Embodiment] An embodiment of an endoscope apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the first embodiment. A light source unit 19 and a video processor 22 are connected to the endoscope body 10. The light source (22) 20 has an electron gun 44 and a fluorescent screen 52, and after an electron beam 46 from the electron gun 44 is focused by an electron lens 48, a deflection coil 50
Then, the fluorescent screen 52 is scanned two-dimensionally. By being irradiated with the electron beam 46, a spot light generated from the fluorescent screen 52 is imaged on a surface 56 by the imaging lens 54, and then enters the Selfoc fiber lens 18 via the 5-rotation color filter 60. The imaging lens 54 has the role of a relay lens for increasing the amount of light incident on the SELFOC fiber lens 18, and the role of correcting the chromatic aberration of the SELFOC fiber lens 18.A zero-rotation color filter 60 is shown in FIG. Like R (red), G (green), B
Transmissive color filters of three primary colors (blue) are sequentially arranged along the circumference of the disk. The filters of each color are switched by a motor 58 during a rest period when one rask scan of the electron beam is completed.

The spot light incident on the SELFOC fiber lens 18 is magnified by a magnifying lens 16 at the end of the endoscope according to a necessary light distribution angle, and is projected onto the subject 20, thereby illuminating the subject. Therefore, the spot light scans the object 20 according to the rask scan of the electron beam. Further, this spot light is switched to the three primary colors of R, G, and H for each scan.

Reflected light from the subject 20 is photoelectrically converted by a light receiving element 12 built into the tip of the endoscope 12. Since the location photographed by the endoscope is a location where there is no or almost no natural light, such as in a body cavity, only the reflected light from the portion irradiated with the spot light is incident on the light receiving element 12. Here, since the spot light is scanned by rask scanning, the light receiving element 12 outputs two-dimensional distribution information of the reflection intensity on the subject 20 in a time series manner. As a result, even if the light-receiving element 12 does not perform imaging scanning, that is, even if there is only one pixel, the subject is substantially imaged and scanned.

The light receiving signal output from the light receiving element 12 is sent to the preamplifier 14.
is supplied to the video processor 22 via the video processor 22. The received light signal is subjected to necessary signal processing as a TV multiplied signal in a video processor 22 in an AGC (auto gain control) circuit 24 and a γ correction circuit 26, and then digitized by an A/D converter 28. The digitized TV double signal multiplexer circuit 30 performs switching in synchronization with one rask scan of the electron beam, that is, in synchronization with the timing at which each primary color of the rotating color filter 60 is switched.

Then, the frame memory 32-1 for the TV double signal R image when illuminated with the R spotlight is stored in the frame memory 32-1 for the TV double signal G image when illuminated with the G spotlight.
2, the TV @ signal when illuminated with the B spot light is supplied to the frame memory 3z-3 for the B image.

Three component images of R, G, and B are stored in the frame memory 32-1.
．． 32-2.32-3, the signals in each frame memory 32-1.32-2.32-3 are read out in parallel, and each D/A converter 34-1.34-2
．． It is supplied to the color monitor 36 via 34-3.

Switching of multiplexer 30, frame memory 32-
1.32-2.32-3 reading and writing, color monitor 36
is controlled by a timing generator 42 provided within the light source unit 19. The timing generator 42 also controls the rask scanning of the electron beam from the electron gun 44 and the motor 58 that rotates the rotary color filter 60.The rotation of the 6-rotation color filter 60 is controlled by an optical system provided corresponding to the outer periphery of the disk. The output of the rotation detector 62 is supplied to the timing generator 42.

On the other hand, the light reception signal input into the video processor 22 is also supplied to the comparator 40 via the low-pass filter 38. The comparator 40 compares this light reception signal with a reference voltage, and feeds back the difference negatively to the acceleration voltage of the electron gun 44. Thereby, the acceleration voltage of the electron gun 44 is automatically adjusted, and the intensity of the illumination light is automatically adjusted.

According to the first embodiment, since endoscopic imaging is performed under a dedicated light source, instead of scanning the subject on the image sensor, a spot light from the dedicated light source is used to two-dimensionally scan the subject. By writing the reflected light signals outputted in time series from the light receiving element into the memory in accordance with the scanning of the spot light, the light receiving element of one pixel can obtain two pieces of reflection intensity information of the subject.
A dimensional distribution, ie an optical image, is obtained. Therefore, a lens system for forming a subject image on the light-receiving surface is not required.

In this case, the resolution of the captured image can be improved by narrowing the diameter of the spot light or increasing the number of scanning lines, so the subject can be imaged with high resolution without increasing the diameter of the endoscope tip. A capable endoscope device will be realized.

In addition, in the first embodiment, by moving the entrance end of the SELFOC fiber lens 18 in the direction of the illustrated arrow,
The rask scanning range of the spot light on the subject 20 can be varied, and the captured image can be freely enlarged or reduced.

A second embodiment of this invention is shown in FIG. 3.In the second embodiment, instead of switching the three primary colors of illumination with a rotating color filter,
It is equipped with three light sources, and the light from each light source is sequentially irradiated to switch between the three primary colors. Laser oscillation for R, G, and B! ! 70.72°74 are provided, and the laser beams from these laser oscillators 70°72.74 are respectively R.
. be deflected. The X-polarized laser beam reflected by the rotating polyhedral mirror 82 is incident on the rotating polyhedral mirror 84 for deflection in the Y direction (
deflected in the direction perpendicular to the plane of the drawing. The xY polarized laser beam emitted from the rotating polygon mirror 84 is imaged at a surface 88 by an imaging lens system 86 .

Thereafter, the light is incident on the SELFOC fiber lens 18. The rest of the configuration is the same as that of the first embodiment, so a description thereof will be omitted.

With this configuration, each laser oscillator 70, 72, 74 is switched at the same timing as the rotating color filter 60 is switched in the first embodiment, and operates in the same manner as in the first embodiment. The laser beam has a smaller diameter than the electron beam from an electron gun.

The second embodiment can further improve the resolution compared to the first embodiment.

Note that the rotating polyhedral mirrors 82 and 84 may be replaced with optical angle modulators that utilize surface waves.

FIG. 4 shows a third embodiment of the present invention. This embodiment does not include a light source unit, but has a built-in optical angle modulator 94 using a laser oscillator 922 and a surface wave at the tip of the endoscope body 1O. A laser beam is scanned at the end of the endoscope.

This invention is not limited to the embodiments described above, and can be modified in various ways. In the first and second embodiments, the three primary color filters were switched for each frame, but it is also possible to rotate the rotating color filter at high speed and switch the RlG and H illumination for each predetermined pixel. If signal processing similar to that of a single-tube camera using a stripe filter or a solid-state image sensor camera with a color mosaic filter attached to the front is performed, the frame memories 32-1, 32-2, .
32-3 becomes unnecessary.

[Effects of the Invention] As explained above, according to the present invention, the illumination light scans the object instead of the image sensor scanning the object, so there is no need to provide an image sensor as a light receiving means and a single pixel is used as the light receiving means. Therefore, the resolution of the captured image is determined by the diameter of the spot light that two-dimensionally scans the subject and the number of scanning lines, so it is possible to achieve high resolution without increasing the diameter of the endoscope. An endoscope device that can image a subject is provided.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a first embodiment of an endoscope device according to the present invention, FIG. 2 is a diagram showing a rotating color filter used in the first embodiment, and FIG. FIG. 4 is a diagram showing a main part of a second embodiment of a mirror device, and FIG. 4 is a diagram showing a main part of a third embodiment of an endoscope device according to the present invention. 12...-Photodetector 30...Multiplexer 32-1.32-2.32-3...Frame memory 3
6... Color monitor 42... Timing generator 44... Electron gun 50... Deflection coil 52... Fluorescent screen 60... Rotating color filter

Claims (5)

[Claims] (1) An endoscope device comprising means for irradiating a subject with spot light while scanning in two dimensions, and means for photoelectrically converting light reflected from the subject. (2) A storage means having a storage area corresponding to the scanning range of the spotlight is connected to the output end of the photoelectric conversion means, and the output of the photoelectric conversion means is written into the storage means in synchronization with the scanning of the spotlight. The endoscope device according to claim 1, characterized in that: (3) The endoscope apparatus according to claim 1, wherein the irradiation means includes an electron gun, a deflection coil, and a fluorescent screen to which the electron beam from the electron gun is irradiated. (4) The endoscope apparatus according to claim 1, wherein the irradiation means comprises a laser oscillator and a rotating polygon mirror. (5) The endoscope apparatus according to claim 1, wherein the irradiation means includes a laser oscillator and an optical angle modulator.