JPS5846935A - Endoscope apparatus using solid photographing element - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an endoscope device using a solid-state image sensor.

Conventionally, when observing and recording the inside of a biological cavity or a mechanical device, it has been common to use an endoscope, also called a fiberscope. An endoscope called a fiberscope has an imaging optical system that creates at least an image of the object at its distal end, which is inserted into the part to be observed, and an optical image created by the imaging optical system that is transferred to the other distal end. One end of an optical fiber bundle called an image guide transmits light to the object to be examined, and one end of an optical fiber bundle called a light guide serves as an illumination member. to enlarge and observe,
It is widely used for recording in photographs or capturing images with television cameras.

In recent years, due to remarkable progress in semiconductor technology, solid-state imaging devices with reduced self-scanning, such as COD, are beginning to be put into practical use. ,Nle.Compared to the camera tubes such as videocons that were conventionally used in television cameras, this type of solid-state image sensor has the potential to be made smaller and lighter.
A solid-state image sensor is directly incorporated into the tip of the endoscope, and the image of the object to be examined by the imaging optical system is converted into an electrical signal.
14940, etc.) In this case, in order to display television images on a CRT in color, the following method is generally considered as an example of imaging. The first method is the basic method, which separates the image of the subject created by the imaging optical system into 3iL colors (F@, green (G), blue e), and converts the image into these three primary colors. Correspondingly, the second method uses three separate solid-state image sensors.
This method uses 11 solid-state image sensors and performs grid superimposition for each pixel that makes up the solid-state image sensor. Thirdly, in consideration of the structure of the endoscope and the particularity of its use, the light source side K, which provides illumination light to one illumination member of the endoscope, that is, the optical fiber bundle called the above-mentioned light guide. It rotates at a predetermined rotational speed as a three-primary color filter, and is a single solid-state system. However, when these methods are used in endoscopes, the following drawbacks appear. The first method is the most basic and provides good images, but it is impossible to store the thin and small tip of an endoscope. It becomes large and thick, which is a restriction on the use of endoscopes.

The second method obtains a compact KL at the end of the endoscope in terms of shape, but the imaging surface of the solid-state image sensor is color-divided using a mosaic-like 7-1 router of the three primary colors red, green, and blue. Therefore, when determining the resolution, the number of pixels in the green area decreases, leading to a decrease in resolution (this is unavoidable.If the 1st small end of the endoscope is used for special purposes, a solid-state image sensor with a large number of pixels will not be enough. In this case, the reduction in resolution becomes a particularly big problem because it becomes difficult to use.The third method uses one solid-state image sensor in a frame-sequential manner, and
Since the primary color components are extracted sequentially, problems occur in the temporal registration of the three primary color images for objects that move relatively quickly, and deterioration in image quality becomes unavoidable.

The present invention takes into consideration the structure of the endoscope and the particularity of its use, and
The present invention relates to an endoscope device that has improved the above-mentioned drawbacks and has an imaging method that is optimal for an endoscope using a solid-state image sensor, and includes an imaging optical system that forms at least an image of a subject at the distal end. It has a self-scanning solid-state image sensor that converts an image formed by an imaging optical system into an electrical signal, and an illumination means that illuminates the object to be examined.When the solid-state image sensor is illuminated with colored light, the entire solid-state image sensor is When an image signal t corresponding to the sum of the green components of the object is extracted from the pixel and the illumination means is illuminated with magenta six-color light, the cyan color filter of the solid-state image sensor is more sensitive to the object than the arranged pixel. An image signal corresponding to the blue component pressure is extracted, an image signal t corresponding to the red component of the object is extracted from the pixel where the yellow color filter is arranged, and this image signal is processed into color by an image signal processing device. An object of the present invention is to provide an endoscope device using a solid-state image sensor, which is characterized in that it displays a color image on a display device such as a CRT display device as an image signal.

The present invention will be described in detail below using examples.

FIG. 1 shows a schematic configuration of an endoscope device according to the present invention.
Therefore, in the figure, 1 is an endoscope body, 2 is a light source device, 3 is a synchronization circuit, 4 is an image signal processing circuit, and 5 is an image display device such as a CRT. The distal end of the endoscope body 1, which is inserted into the part to be observed, is equipped with a few (including an imaging optical system 12 that forms an image of the subject, a self-scanning solid-state image sensor 13 represented by a CCD cape, and A tip 15 of a light guide 14 as an illumination member for illuminating the test object is incorporated, and color filters of solid-state imaging yellow (7) are arranged in a mosaic pattern. A window glass 11 is provided at the tip of the mirror body 1.
The image is formed on the imaging surface of the light guide 14, and the tip 1 of the light guide 14
The illumination light emitted from 5 illuminates the object to be inspected through the window glass 11Y, and the electric signal of the image from the solid-state image sensor 13 is transmitted to the image signal processing device 4 by the lead wire bundle 15 and displayed on the display device. 5, it is displayed as an image. Here, the negative wire bundle 15 includes a wire that supplies clock signals and the like for driving the solid-state image pickup device, and a circuit for COD driving of these clock signals and the like is used for image signal processing. It shall be included in device 4.

On the other hand, the light source device 2 includes two flash lamps 25 that can flash alternately at high speed. '28%: A 24V magenta filter is placed on one of the flash lamps (25), and a 23V tariff filter is placed on the other flash lamp. Transparent Dike μick mirror 22,
The light is focused onto one end surface 16 of the light guide 14 by a condenser lens 21 via an IR cut filter 27 .

The flash lamps 25 and 26 of this light source device are configured to blink alternately in synchronization with one field of the image in the synchronization circuit shown in 3, but in this figure, the flash lamps 25 and 26' are turned on. Power sources are omitted and not shown.

As an example in FIG.
If the image is illuminated with green light (generated by the flash lamp 26 and green filter 23) as shown in FIG. Since cyan and yellow (2) color filters are arranged in each pixel as shown in Fig. 2, the pixels with cyan filters arranged as shown in Fig. 3 also
Since the signal (G) of the talin component of the test object as shown in Fig. 4 is also extracted from the pixels where the yellow filter is arranged, the signal of the green component of the test object is extracted from all the pixels of the solid-state image sensor. It is taken out. Next, in the second field +° (even fields of 4th, 6th, etc.), the magenta light (produced by the flash lamp 27 and magenta filter 24) shown in FIG. 3 is illuminated. As shown in Fig. 4, the signal (B) of the blue component of the object is extracted from the pixel in which the cyan filter in Fig. 2 is arranged, and the signal (B) of the blue component of the object is extracted from the pixel in which the Yep-filter is arranged. The signal of the red component @) of the object will be extracted. That is, from the 27th wing, the blue component of the object and the 11th signal are obtained. In this case, since the IIL image power of the blue TV to be tested is determined by the signal of the green component, by extracting the signal as described above, the resolution of the color image will not deteriorate;
Since all the color component signals of the object to be inspected are absorbed in the field, this method is better than method K, which sequentially extracts images of the three primary colors mentioned earlier!
Since the time required is 1/3, the problem of temporal registration of the three primary color images, which was a problem in the third method described above, is improved. As shown in Figure 1, when
Since an I-cut filter is used, for example, if an IR-cut filter with characteristics as shown in Fig. 5 is used, the spectral characteristics of the system as shown in Fig. 6 can be obtained, resulting in good color reproduction and the above-mentioned signal. The processing circuit alternately displays the green image signal and the blue and red image signals for each field on the color TV monitor, or stores the green image signal and the blue and red image signals once in memory. In this way, according to the present invention, one solid-state image pickup device is used. Despite using k, the resolution and image deterioration due to storage power consumption are significantly improved compared to the methods proposed so far.°,j! Since the distal end of the endoscope can be constructed in a small size, it is possible to achieve a very large effect, especially when the shape and size of the distal end of an endoscope are subject to restrictions.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an endoscope device according to the present invention, Fig. 2 is a plan view of a mosaic filter used in the solid-state image sensor of Fig. 1, and Fig. 3 is a diagram of a light source light consisting of green light and magenta light. Figure 4 shows the spectral distribution and spectral transmittance of a mosaic filter consisting of cyan and yellow.
Figure 5 is a diagram showing the distribution of color component light obtained by combination K of light source filters, Figure 5 is a diagram showing the spectral transmittance of the IR cut filter, and Figure 6 is a diagram showing the spectral transmittance of the IR cut filter.
It is a distribution diagram of the color component light of a figure. 1... Endoscope, 12... Imaging optical system, 13.
・Solid-state image sensor, 14 ・Illumination means, CF ・・
・Cyan filter, Y...Yellow filter. Applicant Fuji Photo Koki Co., Ltd. @ 2 Zuji 3 WJ Ling Endoscope Makoto using Seiko 5, relationship with the case of the person making the correction Address of the patentee: 1-32i, U'fiH-cho, Saitama Prefecture, Box 6, Amendment of white ginseng (1) Specification No. U Change “006 Color Hyakgen” on the 19th line of the page to “0”
I'm looking forward to 00 color reproduction, ``e-kiru.'' he says.

Claims (1)

[Claims] 1. In an endoscope that observes and records the inside of a biological cavity or mechanical device, the tip inserted into the biological cavity or mechanical device has at least a lens that creates an image of the object to be examined. It has an imaging optical system, a self-scanning solid-state imaging device that converts an image formed by the imaging optical system into an electric signal sum, and an illumination means for illuminating the object to be inspected, and the solid-state imaging device includes a solid-state imaging device. When the green color light is illuminated by each means, the green component of the object to be examined is extracted from all pixels of the solid-state image sensor, and when the illumination means is used to illuminate the magenta color light, the image signal is extracted from all the pixels of the solid-state image sensor. An image signal corresponding to the blue component of the test object is extracted from the pixel where the cyan color filter is arranged, and an image signal corresponding to the red component of the test object is extracted from the pixel where the yellow color filter is arranged. An endoscope device using a solid-state image sensor characterized by forming a color image by taking out a page.