JPS62174716A - Endoscope device - Google Patents

Abstract

PURPOSE:To speedily and easily discriminate an affected part and normal parts by providing a means which lights a body to be observed with infrared wavelength range light and visible wavelength range light, an optical system and a solid-state image pickup device, and a means which separates light on the transmission surface of the device. CONSTITUTION:The body to be observed is lighted with rays of light in the infrared ray range and visible ray range and an image signal is sent to a switching circuit 52 through an image forming lens 4 and the solid-state image pickup device 5 at the tip part of an endoscope. Filter parts 45a-45c having wavelength selectivity are checkerboarded on the light receiving surface of the device 5, a wavelength range of 600-900nm is divided into three, and rays of light of the three primary colors which are transmitted them are processed to display an image on a monitor. TV. The normal parts and abnormal part of the patient have a difference in the reflection factor of wavelength light, so they are discriminated speedily and easily on the monitor TV.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an endoscope device used for observing the inside of a living body cavity or a cavity such as a mechanical component.

Conventionally, in such endoscopes, an image of the object to be observed is led out of the living body cavity or cavity through an optical fiber east, and an optical image formed on the output end face of the optical fiber is transmitted through an eyepiece system. I am observing. Another method is to install a solid-state imaging device at the tip of the endoscope sheath instead of the optical fiber described above, and convert the optical image formed on the light-receiving surface of this solid-state imaging device into an electrical signal. It has also been proposed to lead the signal out of the subject's body cavity or cavity using a wire, perform necessary signal processing, and then display it on a TV monitor.

In the endoscope described above, the information received from the object to be observed by ILF is fixed in the visible light wavelength region.

In other words, in the former case, the image is optically viewed directly with the naked eye, so of course it is impossible to observe anything outside the visible wavelength range, while in the latter case, solid-state imaging devices are also sensitive to infrared wavelengths, so infrared wavelengths cannot be observed. Image information in the region can be detected, but when colorizing the image, image information in the infrared wavelength region becomes a hindrance to achieving color balance. Therefore, in order to improve color fidelity, infrared cut filters are usually used to reduce the infrared wavelength range. It is necessary to prevent bright light from irradiating the object to be observed, or to provide a filter that prevents bright light from reaching the light-receiving surface of the solid-state imaging device even if it is irradiated.

When observing an image of an object to be observed using such an endoscope, it is necessary to detect subtle differences in color tone to distinguish between an affected area and a normal area, especially in a living body. Generally, detecting (recognizing) the difference requires a high degree of knowledge and experience, and it takes a long time to detect it, and requires concentrated attention during the detection.

The present invention aims to eliminate the above-mentioned drawbacks and to make it possible to quickly and easily distinguish between affected areas and normal areas. Regarding observation of affected areas and normal areas in a living body. , as a method to increase the identification ability of endoscopic devices.
The present invention employs a method of converting invisible information obtained by infrared irradiation into visible information. As is generally known, solid-state imaging devices have high sensitivity in the near-infrared region. It is also known that illumination light sources generally emit more energy in the infrared wavelength region than in the visible wavelength region. By the way, it can be predicted that the amount of light reflected from an object to be observed is large in the red (long wavelength) side of the visible light wavelength region in a living body because blood is red in color. It has also been announced that the reflectance increases with near-infrared light. For these reasons, there is a good possibility that information obtained from infrared light in a living body is useful for extracting features in a living body. Image information obtained using infrared light in this way is displayed on a TV monitor in colors of specific wavelengths. Only images in different infrared wavelength regions are
It may be displayed in (red), (green), and (blue) on the V monitor, or it may be displayed in (red), (green), (blue), or it may be displayed in the visible wavelength region (for example, red image) and in the infrared wavelength region. may be displayed simultaneously. In short, it is important to be able to extract image signals in a wavelength range that characterizes an affected area within a living body as a normal area.

The endoscope apparatus of the present invention includes means for simultaneously illuminating an object to be observed with at least one light in an infrared wavelength region and at least one light in a wavelength region different from the infrared wavelength region; An optical system is installed at the tip of the part to be inserted into the inside of the camera, and receives light from the object to be observed to form an image of the object on the imaging plane. a solid-state imaging device that converts an observed object image into an electrical signal; a filter disposed between the optical system and the solid-state imaging device that separates light in each of the wavelength regions; A plurality of frame memories each storing electrical signals representing images of an object to be observed using light in a wavelength range, and means for displaying an image in response to electrical signals selectively read out from the plurality of frame memories. It is characterized by:

Next, the present invention will be explained in detail according to the drawings.

Figures 1A and 1B show reflection spectra of human organs.

The 11th fflA is the gastric spectrum, and is mostly 400n
It is flat up to a wavelength of m to 1200 nm, and its reflectance is several 10%. On the other hand, Figure B is the spectrum of blood.
From 400 nm to 1200 nm, it varies from a few % to nearly 100%. Comparing the two, it can be seen that the difference is particularly large in the infrared wavelength region (800 nm to 1200 nm).

For example, if there is tissue that resembles blood or something that contains multiple blood layers in the stomach, and you are trying to recognize its existence, the difference will be clearer if you compare it in the near-infrared wavelength region. However, it is clear that the effect is significant.

Current optical endoscopes have a human specific luminous efficiency (400 nm).
It is possible to make a judgment by observing only in the wavelength range (~700 nm). On the other hand, the sensitivity range of CCD is 400nm
This ranges from 1200 nm to 1200 nm, which is sufficient to obtain information in the near-infrared wavelength region.

Furthermore, light source lamps used as general light sources emit a large amount of energy in the near-infrared wavelength region rather than visible light. Irradiating an object to be observed with wavelengths in the near-infrared wavelength region requires only shifting the spectral characteristics of commonly used infrared cut filters to longer wavelengths, and there is no technical difficulty.

FIG. 2 shows the distal end of the portion inserted into the body cavity of an example of an endoscope device developed by the present inventors. This example is a direct viewing type, in which light from a light source (see FIG. 3) is guided into the interior by a light guide 1, and the object to be observed is illuminated through a glass window 2 for illumination. Reflected light from an object to be observed is taken in through an imaging glass window 3, and is imaged by an imaging lens 4 on a light receiving surface of a self-scanning two-dimensional solid-state imaging device 5 such as a CCD or BBD. This solid-state imaging device 5 has a large number of photosensitive elements arranged in a plane. The output signal is led out through the lead wire bundle 6. This lead wire bundle 6 is connected to an external oscillator (see Figure 3).
It also includes a lead wire for supplying a clock signal for operating the solid-state imaging device 5 from the solid-state imaging device 5 . Solid-state imaging device 5
A filter 45, which will be described later, is placed in front of the filter.

The light guide 1 and the lead wire bundle 6 are inserted into the sheath 7. Further, the lens 4 and the solid-state imaging device 5 are placed inside the outer case 8, which is placed at the tip of the stem 7.

FIG. 3A shows the construction of one embodiment of the externally arranged part. A light source 21 is arranged opposite to the entrance end face 1a of the light guide 1 which projects from the end of the sheath 7. Light #i21 emits infrared rays and visible rays, and the rays emitted therefrom enter the incident end face 1a of the light guide I and are used as illumination light for the object to be observed. Since the core of the light guide 1 is generally made of multi-component glass, it is attenuated in the near-infrared wavelength region, so it is desirable to use a bundle of fibers whose core material is made of quartz or the like, which does not attenuate even in the near-infrared wavelength region. . A color switching signal circuit 25 comprising a current amplifier and a level detection circuit is provided to generate timing signals for each of the blue, green and infrared filters 45. Furthermore, the output of the current amplifier of such a color switching signal circuit is differentiated, and the levels are made uniform to be used as a trigger signal for the oscillation circuit 27.

The signal switching circuit 28 receives the image signal led out from the imaging device 5 via the lead wire bundle 6 via the amplifier 26, and outputs it to each different output terminal in synchronization with the color type of light incident on the light guide 1. 288.28G and 28R. This signal switching circuit 28 uses a high-speed operating switch such as a semiconductor analog switch. The oscillation circuit 27 receives the trigger signal from the color switching circuit 25 and supplies a scanning signal for the imaging device 5 and a synchronization signal to the horizontal deflection circuit 32 and vertical deflection circuit 33 of the monitor cathode ray tube 34. The horizontal deflection circuit 32 is a monitor cathode ray tube 3.
The vertical deflection circuit 33 is composed of an output amplifier for deflecting each of the blue, green and red beams of 4 in the horizontal direction, and the vertical deflection circuit 33 is composed of an output amplifier for deflecting these beams in the vertical direction.

Output terminals 28G, 28R and 28 of the signal switching circuit 28
Each output from B is sent to frame memories 38a and 38, respectively.
b, 38c. The green amplifier 29, the red amplifier 30 and the blue amplifier 2B are set so that the signals read from these frame memories have sufficient voltage to operate the green, red and blue gratings of the monitor cathode ray tube 34.
31 respectively.

FIG. 3B is a diagram showing the configuration of an embodiment of the part disposed outside, in which 6' is a signal line from the solid-state imaging device;
5 is an amplifier; 36 is an A/D converter; 37 is a switching circuit that is switched by a signal from the color switching signal circuit 25;
38a, 38b, and 38C are memories that store information in each wavelength range, and 39 is a T necessary for displaying on a TV monitor.
This is a V signal processing circuit. In this example, information in three wavelength regions is sequentially allocated to multiple wavelength regions in memory 33a.
, 38b and 38C, and if not read, they are read simultaneously to perform signal processing suitable for a TV monitor. Memo! J38a, 38b, and 38C are provided with a refresh function to read the same signal many times. Also each note! J38a, 38b and 38C each consist of a memory for the anti-number, and can be corrected while being read.

FIG. 4 is a diagram showing an embodiment of the filter 45 of the present invention. In this example, filter portions 45a, 45b, and 45c having wavelength selectivity are arranged in a checkerboard pattern on the light receiving surface of the solid-state imaging device.
At least one of them is transparent only in the infrared wavelength region.

For example, the filter portion 45a is R (red) and the filter portion 45b is G.
(green) and 45c can also be determined as IR (one of the infrared wavelength regions). The signal obtained from the solid-state imaging device is processed in a manner similar to the signal processing of known single-chip color TV cameras to separate image signals according to each wavelength region and display a color image on the TV screen. Perform signal processing where possible.

The transmission wavelength of the three parts 45a, 45b, and 45C of the filter 45 is in addition to the above-mentioned example.
nm to 800 nm (red), part 45b is 800 nm
~900 nm (infrared region), portion 45c is ~600 nm
It is also possible to transmit light of each wavelength of 700 nm (orange color). The signal switching circuit 28 is driven in synchronization with the scanning of the filter 45 portion, and an image signal obtained by, for example, the light transmitted through the red portion 45a is supplied to the green channel via the green output terminal 28G, and is used for monitoring. A green image is projected on the cathode ray tube 34, and an image signal obtained by the light transmitted through the infrared region portion 45b is displayed as a red image via the red output terminal 28R.
The image signal obtained by the light transmitted through 5C is sent to the blue output terminal 28.
B can be displayed as a blue image. In this case, the image signals obtained from each illumination light wavelength range do not necessarily need to be displayed in the same or similar colors on the monitor cathode ray tube 34; for example, the output corresponding to the portion 45a may be displayed in red, and the output corresponding to the portion 45b may be displayed in red. It is naturally possible to display it in blue and that in section 45C in green. Although there are many combinations, these combinations may be used in such a way that it is easiest to distinguish between the affected area and the normal area.

Various wavelength ranges can be set for each part of the filter used in the present invention as shown in Table 1. However, the combination of wavelength regions is not limited to this.

Table 1 FIG. 5 is a diagram showing an endoscope device of the present invention incorporating the filter 45 shown in FIG. optical filter 45
The light is made incident on the solid-state imaging device 5 through the . A signal from the solid-state imaging device 5 is supplied to a switching circuit 52 via an amplifier and a clamp circuit 51. This switching circuit 52
are synchronously driven by the solid-state imaging device drive circuit 53, and the signals obtained from each wavelength region of the filter 45 are sequentially transmitted to the green, 1TE, and red channel amplifiers and filters 54a,
54b and 54c. These output signals are stored in frame memories 56a, 55b, and 56C, respectively. The signals selectively read out from these frame memories are further supplied to a signal processing circuit 55 to obtain a predetermined color signal suitable for a TV monitor.

FIG. 6 shows still another embodiment of the filter used in the endoscope apparatus of the present invention. Filter portion 4 of filter 46 in this example
6a and 46b constitute a so-called stripe filter 46 that transmits a red image signal and a green image signal, respectively.

FIG. 7 is a side view showing an example of a photolysis system used in the endoscope apparatus of the present invention when the filter shown in FIG. 6 is used. In this case, two solid-state imaging devices 25a and 5b are used. That is, one solid-state imaging device is for obtaining an image signal in a specific wavelength range, and the other solid-state imaging device is for obtaining an image in another specific wavelength range or a plurality of wavelength ranges, and at least one of the wavelength ranges is It is characterized in that it is for obtaining an image in an infrared wavelength region. For example, the light 9 reflected from the object to be observed and passed through the lens is reflected by the pentaprism 10.
The infrared wavelength region light is reflected by the gitaloic surface 11, and the red light and green light are transmitted and go straight. The infrared wavelength region light 12 reflected by the guichroic surface 11 is reflected again by the mirror surface 13 and enters the first solid-state imaging device 5a via the infrared transmission filter 47. The light transmitted through the guichroic surface 11 passes through the light-transmitting block 14, and due to the filtering action of the filter portions 46a and 46b of the stripe filter 46, red light and green light are transmitted, and are transmitted to the second solid-state imaging device 5b. incident.

FIG. 8 is a diagram showing an example of a configuration in which the photolysis system shown in FIG. 7 is incorporated into a portion of the endoscopic device of the present invention to be inserted into a body cavity.

In this example, the reflected light from the object to be observed is captured by the imaging glass window 3.
, the imaging lens 4, the pentaprism lO, the light-transmitting block 14, and the solid-state imaging devices 5a and 5.
imaged by b, photodecomposed, and converted into electrical signals. The lead wire bundle 6 accommodates lead wires for taking out video signals from the imaging devices 5a and 5b, and the other lead wires are stored in the second lead wire bundle 6.
The configuration is as shown in the explanation of the figure.

FIG. 9 is a reflection curve diagram of the normal part and diseased part 3 in the living body cavity, where the reflection curve of the normal part is shown by Δ, and the reflection curve of the diseased part δ:S is shown by B. Now, spectroscopy is performed using a spectral filter that passes the el, β2, and β3 wavelength regions, and the electrical signals obtained from the solid-state imaging device by the light in these wavelength regions are, for example, R (red), G (green), and B, respectively. When displaying an image in synchronization with the (blue) electrical signal, the reflection curve Δ traces a nearly flat trajectory in the normal area, so R, G, and B
The reflectance of the light becomes constant, and as a result, the colors are mixed and become white. However, when looking at the affected area, it shows a trajectory similar to reflection curve B in the wavelength range 11. Each reflectance at β2 and β3 is α
, β, and T, the colors are mixed at a ratio of αR+βG0rB, so that the colored affected area is clearly displayed in color on a normal white display device. In the visible range, even if it passes through a conventional visible range R, G, and B filter, reflection curve A and reflection curve B are almost the same, so
It is difficult to distinguish between a normal part and an abnormal part using a display device.

The present invention is not limited to the above-mentioned examples, and can be modified and modified in many ways. Although the above example describes an example in which images in three wavelength regions are obtained, the present invention is not limited to this. Even more information can be obtained by using a large number of wavelength regions. In this case, currently popular TV monitors display R (red) and G (green).
, B (blue), and a mixture of these colors displays images of various tones. Therefore, a color image of three or more colors may be displayed by mixing these colors. In other words, it is conceivable to once store images for each wavelength region in a frame memory and to sequentially switch over the images, read out image signals from the memory in three wavelength regions at a time, and display them in three primary colors on a TV monitor.

As detailed above, according to the endoscope device of the present invention, three
In the case where the primary color image signals corresponding to the object color images are sequentially generated in time series by rotating the color separation filter, the fidelity of color balance in the process of color separation-signal transmission and one-color synthesis, which has been considered a drawback, has been improved. can be increased.

In other words, the causes of the above-mentioned shortcomings were: ■ Poor blue sensitivity of solid-state image sensors, ■ Difficulty in achieving the ideal color temperature of illumination light, and ■ Distortion in signal transmission paths and signal processing circuits. It is possible to eliminate various causes of incomplete exclusion, ■ failure to reach the ideal state of each primary color emission spectrum of CRT at the stage of photosynthesis, etc.
It is possible to easily and quickly distinguish between affected parts and normal parts inside a living body, and in addition, it has the effect of making it possible to expect more accurate detection than ever before.

[Brief explanation of drawings]

1A and 1B are diagrams showing the state of the reflection spectrum of one internal organ of the human body; FIG. 2 is a sectional view showing the tip of a portion of an example of the endoscopic device according to the present invention to be inserted into a body cavity; and FIG. Figures Δ and B are diagrams showing the i and li configurations of the parts placed outside the endoscope of the present invention (Fig. 4 are diagrams showing a filter used in the endoscope apparatus of the present invention, respectively. FIG. 5 is a configuration diagram showing an example of an endoscope apparatus of the present invention using the filter shown in FIG. 4, FIG. 6 is a diagram showing still another example of the filter, and FIG. A side view showing an example of the photolysis system used in the device of the present invention when a filter is used, and FIG. 8 is a configuration in which the photolysis system of FIG. 7 is incorporated into the part of the device of the present invention that is inserted into the body cavity. A diagram showing an example, and FIG. 9 is a diagram showing reflection curves for a normal part and an affected part in a living body cavity. 1... Light guide 2... Glass window for illumination 3
...Imaging glass window 4...Imaging lens 5.5a
, 5b...Solid-state imaging device 6...Lead wire bundle 6'...Signal line 7 from the solid-state imaging device...I! S8-Outer box 9...Light passing through lens 10...Penk prism 11...Dichroic surface 12...Infrared wavelength region light 13...Mirror surface 14
...Light transmitting block 21...Light source 25...Color switching signal circuit 26...Amplifier 27...
・Oscillation circuit 28...Signal switching circuit 28R...
・Red output terminal 28G...Green output terminal 28B...Blue output terminal 29...Green amplifier 30...Red amplifier 31
...Blue amplifier 32...Horizontal deflection circuit 33.
・Vertical deflection circuit 34 ・Monitor cathode ray tube 35 ・Amplifier 36 ・A/D converter 3
7... Switching circuits 38a, 38b, 33c... Information storage memory 39...
-TV signal processing circuits 40.41, 42.45a, 45b, 45c, 46a,
46b...Filter portion 45.46.47...Filter 51...Amplifier/clamp circuit 52...Switching circuit 53...Solid-state imaging device drive circuit 54a, 54b, 54c...Signal amplifier/filter 5
5... Signal processing circuits 56a, 56b, 56c... Frame memories 't,'
r Applicant Olympus Optical Industry Co., Ltd. Figure 1, Ma Lecture t, -1 Figure 4 Figure 5 Procedures Amendment Written February 23, 1988 Commissioner of the Patent Office Black 1) Toshio Akira 1986 Patent application filed on January 24th (6) 2, name of the invention endoscope device 3, relationship with the amended person case Patent applicant (037) Olympus Optical Industry Co., Ltd. 4, attorney 1, specification No. On page 3, lines 2 and 3, "because it is sensitive to light" is corrected to "because it has sensitivity." 2. On page 8, line 11, ``attenuate, so'' is corrected to ``attenuate,''.

Claims (1)

[Claims] 1. means for simultaneously illuminating an object to be observed with at least one light in an infrared wavelength range and at least one light in a wavelength range different from the infrared wavelength range; An optical system is installed at the tip of the part inserted into the interior and forms an image of the object on an imaging plane by receiving light from the object to be observed. a solid-state imaging device that converts a body image into an electrical signal; a filter that is arranged between the optical system and the solid-state imaging device and separates light in each of the wavelength regions; A plurality of frame memories each storing electrical signals representing an image of an object to be observed by light in a region, and means for displaying an image in response to electrical signals selectively read out from the plurality of frame memories. Features of the endoscopic device.