JPS62174712A - Endoscope device - Google Patents

Abstract

PURPOSE:To speedily and easily identify between an affected part and normal parts by providing a means which irradiates a body to be observed with light which has the infrared range and visible ray range in time series, an optical system, and a solid-state image pickup device. CONSTITUTION:An infrared ray and a visible ray from a light source 21 are incident on a photoconductor 1 through a rotary filter 22 to light the object of a patient at the tip part of an endoscope and then an image signal is sent to a signal switching circuit 28 through the solid-state image pickup device. Light reflected by a half-mirror 23, on the other hand, is sent to the circuit 28 through a photodetecting element 24. The filter 22 sections a wavelength range of 700-1,200mm into three and the three primary colors passed through the respective section are mixed to display an image on a monitor TV 34. At this time, normal parts of the patient are constant in reflection factor to each color and become white after color mixture, but an abnormal affected part differs in reflection factor. Consequently, the affected part is easily and speedily identified from the normal parts.

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 guided outside the living body cavity or cavity using an optical fiber bundle, and an optical image formed on the output end surface 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 the device into an electrical signal. It has also been proposed to lead the signal out of the body cavity or cavity using a lead wire, perform necessary signal processing, and then display it on a TV monitor.

In the endoscope described above, the information obtained from the object to be observed is limited to the visible light wavelength region.

In other words, in the former case, the image is viewed optically directly with the naked eye, so it is naturally impossible to observe anything outside the visible light wavelength range, and in the latter case, the solid-state imaging device is also sensitive to infrared wavelength ranges, so image information in the infrared wavelength range cannot be observed. can be detected, but when colorizing an image, image information in the infrared wavelength region becomes a hindrance to achieving color balance. Therefore, in order to improve color fidelity, it is common practice to use an infrared cant filter to prevent illumination light in the infrared wavelength region from irradiating the object to be observed, or even if it is irradiated, the light receiving surface of the solid-state image pickup device It is necessary to provide a filter to prevent this from occurring.

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.

It is an object of the present invention to eliminate the above-mentioned drawbacks and to make it possible to quickly and easily distinguish between an affected area and a normal area. As a method for increasing the discriminating ability of an endoscope apparatus for observing affected and normal parts within a living body, the present invention adopts 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. TV displays only images in different infrared wavelength regions
You can display (red), (green), and (blue) on the monitor, or you can simultaneously display what is obtained in the visible light wavelength region (for example, a red image) and what is obtained in the infrared wavelength region. It may also be displayed. 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 chronologically illuminating an object to be observed with light having at least one infrared wavelength region and light having at least one visible wavelength region; and an interior of the object to be observed. An optical system is installed at the tip of the part to be inserted into the object and forms an image of the object on the imaging plane by receiving light from the object. a solid-state imaging device for converting an optical image into an electrical signal; and means for receiving an electrical signal representing an image of an object to be observed by light in each of the wavelength ranges outputted from the solid-state imaging device and displaying the image. It is characterized by this.

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

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

Figure 1A is the spectrum of the stomach, which is mostly 400 nm ~
It is flat up to a wavelength of 1200 nm, and its reflectance is several 1
It is 0%. On the other hand, Figure 1B shows the spectrum of blood, 40
It varies from several % to nearly 100% from 0 nm to 1200 nm. Comparing the two, we find that especially in the infrared wavelength region (8
It can be seen that the difference is large between 00 nm and 1200 nm).

For example, if there is tissue resembling blood or something that contains a large amount of blood 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 can only be observed and judged in the wavelength range of ~700nm).On the other hand, the sensitivity range of COD is 400nm.
m 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 a portion of an example of the endoscopic device according to the present invention that is inserted into a body cavity. This example is a direct view type, and the light source (
3) is guided inside by a light guide 1 and illuminates the object to be observed 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 also includes lead wires for supplying a clock signal for operating the solid-state imaging device 5 from an external oscillator (see FIG. 3).

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 an outer case 8, which is placed at the tip of the sheath 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. The light source 21 emits infrared rays and visible rays, and the rays emitted from the light source pass through a rotating filter 22 and enter the incident end surface 1a of the light guide 1.
It is used as illumination light for the object to be observed. The core of the light guide l is
In general, multi-component glass attenuates in the near-infrared wavelength region, so it is desirable to use a bundle of fibers whose core material is quartz or the like, which does not attenuate even in the near-infrared wavelength region. The rotary filter 22 is arranged so as to be rotated at a constant speed by the motor 20 at a predetermined speed. The light receiving element 24 and the color switching signal circuit 25 constitute a switching pulse generating circuit,
A passing wavelength range that changes depending on the rotation angle of the rotary filter 22 is detected, and the drive pulse of the solid-state imaging device 5 and the image signal obtained from the solid-state imaging device 5 are synchronized with the rotation of the rotary filter 22. That is, the light reflected by the half mirror 23 is made incident on the light receiving element 24, and the output of this light receiving element 24 is supplied to the color switching signal circuit 25. The color switching signal circuit 25 is composed of a current amplifier and a level detection circuit,
The output current signal of the light receiving element 24 is converted into a voltage signal, and a level detection circuit generates timing signals for each of blue, green, and red. 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. It performs the operation of supplying signals to 28B, 28G, and 28H. This signal switching circuit 28
A high-speed operation switch such as a semiconductor analog switch is used for this purpose. The oscillation circuit 27 receives the trigger signal from the color switching circuit 25 and outputs the scanning signal of the imaging device 5 and the horizontal deflection circuit 32 and vertical deflection circuit 3 of the monitor cathode ray tube 34.
Provides synchronization signal to 3.

The horizontal deflection circuit 32 consists of an output amplifier for deflecting the blue, green, and red beams of the monitor cathode ray tube 34 in the horizontal direction, and the vertical deflection circuit 33 consists of an output amplifier for deflecting these beams in the vertical direction. do.

Output terminals 28G, 28R and 28 of the signal switching circuit 28
The respective outputs from B are supplied to a green amplifier 29, a red amplifier 30, and a blue amplifier 31, respectively, so that the voltages are sufficient to operate the green, red, and blue gratings of the monitor cathode ray tube 34.

FIG. 3B is a diagram showing the configuration of still another embodiment of the externally arranged portion, 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 switches in synchronization with the rotary filter 22, 38a, 3
8b and 38c are memories for storing information in each wavelength range, and 39 is a TV signal processing circuit necessary for displaying on a TV monitor. In this example, information on three wavelength regions is written in time series in the memories 38a, 38b and 38C allocated to each wavelength region, and when read out, the information is read out simultaneously, and T
Performs signal processing suitable for V monitor.

Memories 38a, 38b, and 38c are provided with a refresh function to read out the same signal many times. Further, each of the memories 38a, 38b, and 38c is composed of a plurality of memories, and can be written while being read.

FIG. 4 shows the rotating filter 22. FIG. The rotating filter 22 is equally divided into three parts 40, 41 and 42, e.g.
Part 40 is 700 nm to 800 nm (red), part 41
is 800 nm to 900 nm (infrared region), part 42
shall transmit light of each wavelength of 600 nm to 700 nm (orange). The signal switching circuit 28 is driven in synchronization with the rotation of the filter 22, and, for example, an image signal obtained by the light transmitted through the red portion 40 is supplied to the green channel via the green output terminal 28G, and the image signal is sent to the monitor cathode ray tube 34. The image signal obtained from the light transmitted through the infrared region portion 41 is displayed as a red image via the red output terminal 28R, and the image signal obtained from the light transmitted through the orange region 42 is displayed as a blue image. It can be displayed as a blue image via the output terminal 28B. In this case, the image signals obtained from each illumination light wavelength region 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 40 is displayed in red, the output corresponding to the portion 4
It is naturally possible to display the portion 1 in blue and the portion 42 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.

Each part of the rotating filter 22 used in the present invention can be set to various wavelength ranges as shown in Table 1. However, the combination of wavelength regions is not limited to this. In this embodiment, the incident end surface 1a has a circular shape, but it may have a slit shape or a rectangular shape.

Table 1 In the example described above, the rotating filter 22 was provided in the illumination optical system and the object to be observed was sequentially irradiated with one light in the infrared wavelength region and two lights in the visible wavelength region. For example, the object to be observed can be illuminated with light in a plurality of infrared wavelength regions or light in one visible wavelength region.

FIG. 5 is a reflection curve diagram of a normal part and an affected part in a living body cavity, where the reflection curve of the normal part is shown as A, and the reflection curve of the affected part is shown as B. Now 1. , It2, and l are used to separate the light using a spectral filter that passes through the wavelength ranges of R (red), G (green), and B(), respectively. When an image is displayed in synchronization with an electrical signal of blue (blue), the reflection curve A of the normal part draws a substantially flat trajectory, so the reflectance of R, G, and B is constant, and as a result, the colors are mixed and become white. However, when looking at the affected area, the reflection curve B shows a 9-point locus in the wavelength range 1. ,! ! , and each reflectance in 13 is α
, β and γ, the colors are mixed at a ratio of αR+βG+γB, 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, the reflection curve B is almost the same, so
It is difficult to distinguish between a normal part and an abnormal part using a display device. Of course, in the present invention, since at least one light in the visible wavelength range is used in addition to the light in the infrared wavelength range, the location of the abnormality can be easily and accurately identified.

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 images of various tones are displayed by mixing them, so it is possible to display color images of three or more colors by mixing them, or by changing each wavelength region. It is also conceivable to once store the images in a frame memory and sequentially switch them, read out the 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 primary color image signals corresponding to the subject color images are sequentially obtained in time series by rotating the color separation filters,
It is possible to improve the fidelity of color balance in the process of color separation-signal transmission and one-color synthesis, which has been considered a drawback. 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 to identify the affected part easily and accurately.In addition, it is possible to expect more accurate detection than ever before. It is effective.

[Brief explanation of drawings]

1A and 1B are views showing the state of the reflection spectra of human organs; FIG. 2 is a sectional view showing the tip of the endoscope device according to the present invention inserted into a body cavity; FIG. 3A and B are diagrams showing the configuration of the parts disposed outside the endoscope device of the present invention, respectively, and FIG. 4 is a diagram showing a rotary filter used in the endoscope device of the present invention shown in FIG. 2. FIG. 5 is a diagram showing reflection curves for a normal part and an affected part in a living body cavity. ■...Light guide 2...Glass window for lighting 3
...Imaging glass window 4...Imaging lens, 5,5
a, 5b...solid-state imaging device 6...lead wire bundle 6'...signal line 7 from the solid-state imaging device...sheath 8...outer casing 9...light passing through the lens 10...・Penta prism 11...Gicroic surface 12...Infrared wavelength region light 13...Mirror surface 14
...Light transmitting block 20...Motor 21...Light source 22...
Rotating filter 22a... Optical filter 23...
Half mirror 24... Light receiving element 25... Color switching signal circuit 26... Amplifier 27... Oscillation circuit 2
8...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, 38cm--Information storage memory 39...
・TV signal processing circuit 40.41.42...Filter part Figure 1; Anti-moxibustion (nrn) Figure 2 Procedures Correction February 23, 1981 Commissioner of the Japan Patent Office Black 1) Akio Tono 2, Name of the invention Endoscope device 3, person making the correction Relationship to the case Patent applicant (037) Olympus Optical Industry Co., Ltd. 4, attorney 1, “Because it is exposed to light” on page 2 of the specification, lines 16-17 should be corrected to "because it has sensitivity." 2. In the first line of page 8, ``attenuate, so'' is corrected to ``attenuate, so''.

Claims (1)

[Claims] 1. A means for illuminating an object to be observed in time series with light having at least one infrared wavelength region and light having at least one visible wavelength region; An optical system is installed at the tip of the part to be inserted, and forms an image of the object on the imaging plane by receiving light from the object. A solid-state imaging device that converts an optical image into an electrical signal, and a means for displaying an image by receiving an electrical signal representing an image of an object to be observed by light in each of the wavelength ranges described above output from the solid-state imaging device. An endoscope device featuring: