JPS641001B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image processing device for an endoscope that can widen the recommended range when taking TV pictures of inside a living body or the like using an endoscope.

Generally, when observing the inside of a living body on TV using an endoscope, the brightness of the area to be observed depends on the monitor TV.
Since the shading of the projected image changes, the output of the light source device that supplies illumination light to the endoscope is controlled depending on the brightness of the observed region. That is, conventionally, the light intensity of the entire surface or part of an image guide, which is an image transmission optical system of an endoscope, was measured, and the output of the light source device was controlled so that the measured value was constant.

However, in in-vivo TV imaging using an endoscope, although the space inside the living body is narrow, the imaging distance range is wide, so even if the output of the light source device is controlled as described above, the amount of light at the near and far points will vary. The amount of change in the amount of light is large, and this difference in light amount exceeds the shooting ability of the TV device. Therefore, the image of the part of the body close to the endoscope will be pure white, and the image of the part far away will be pure black, so even if the output of the light source device is controlled, the range that can be observed well is very limited. It had the disadvantage of being narrow.

This invention was made based on the above circumstances, and its purpose is to divide an image obtained by an endoscope into a plurality of pixels, electrically process the image signals of each pixel, and then synthesize them. An object of the present invention is to provide an image processing device for an endoscope that can enlarge the observation range regardless of the brightness of the observation region.

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. 1 in the figure is an endoscope. This endoscope 1 consists of an operating section 2 and an insertion section 4 inserted into a living body 3. The operating section 2 has an eyepiece section 5 formed therein and is connected to a light guide 6. A light source lamp 8 is opposed to one end surface of the light guide 6 with a rotary filter 7 interposed therebetween.
As shown in FIG. 2, the rotary filter 7 includes first to third ND filters 9a to 9 having different amounts of transmitted light.
c, and is designed to be rotationally driven by a motor 10. Therefore, the illumination light output from the light source lamp 8 enters the light guide 6 via the first to third ND filters 9a to 9c,
The light is emitted into the living body 3 from the distal end surface of the insertion portion 4 where the other end surface of the light guide 6 is located. It should be noted that an image guide (not shown) is inserted into the endoscope 1, and through this image guide, the region of the living body 3 illuminated by the illumination light can be observed with the eyepiece 5.

A TV camera 11 is detachably connected to the eyepiece 5 of the endoscope 1, and the entire image that can be observed through the eyepiece 5 is input to the TV camera 11. That is, when the rotary filter 7 rotates once, images with three levels of light intensity corresponding to each of the ND filters 9a to 9c are input to the TV camera 11. Furthermore, a discrimination circuit 12 is connected to the TV camera 11, which allows only image signals within a preset level, that is, pixel signals, to pass among the image signals from the TV camera 11.
2 is connected to an A-D conversion circuit 13 that converts the pixel signal passed through the pixel signal into A-D. The A-D conversion circuit 13 includes a write circuit 14 and an image memory 15.
A-
The pixel signals digitized by the D conversion circuit 13 are written into the image memory 15 by the write circuit 14. A readout circuit 16, a DA converter 17, and a monitor TV 18 are sequentially connected to the image memory 15.
The pixel signals read out by 6 are converted into analog signals and displayed on a monitor TV 18. The motor 10, TV camera 11, discrimination circuit 12, write circuit 14, read circuit 16 and monitor TV 18 are connected to the synchronous circuit 1.
It is designed to be synchronized by a synchronization signal from 9. Furthermore, the writing circuit 14 is connected to the discriminating circuit 12.
A write signal is output to the image memory 15 in response to a signal from the image memory 15.

Next, the operation of the above configuration will be explained. The motor 10 is operated by a signal from the synchronization circuit 19, and the rotary filter 7 is rotated, for example, 10 times per second. Then, the first of the rotary filters 7
The ND filter 9a is positioned between the end face of the light guide 6 and the light source lamp 8 for 1/30 seconds, and during that time, an image from the endoscope 1 based on the amount of light transmitted through the first ND filter 9a is displayed on the TV camera 11. is input. In this way, as the rotary filter 7 rotates once, an image from the endoscope 1 based on the amount of light transmitted through the second and third ND filters 9b and 9c is input to the TV camera 11. That is, when the rotary filter 7 rotates once, three images with three levels of light intensity are input to the TV camera 11.

On the other hand, a second ND filter 9 is attached to the TV camera 11.
Until the image with the light amount b is input, the first
The image signal input to the TV camera 11 according to the light intensity of the ND filter 9a is time-divided by the discrimination circuit 12 according to the signal from the synchronization circuit 19, and at the same time,
Only image signals within a preset level, that is, pixel signals, are detected by the discrimination circuit 12.
The signal passes through the A-D conversion circuit 13 and becomes a digital pixel signal. Further, at the same time as the pixel signal passes through the discrimination circuit 12, the write circuit 14
operates, and the pixel signal digitized by the A-D conversion circuit 13 is written into the image memory 15 by the writing circuit 14.

In this way, when a pixel signal based on the light intensity of the second ND filter 9b and a pixel signal based on the light intensity of the third ND filter 9c are sequentially written into the image memory 15, they are The readout circuit 16 reads out the pixel signal, and
- It is converted into an analog pixel signal by the A conversion circuit 17 and sent to the monitor TV 18. Then the monitor
The TV 18 synthesizes pixel signals using the synchronization signal from the synchronization circuit 19 and displays one screen every 1/30 seconds.

That is, according to the above configuration, pixel signals of a predetermined level are extracted from a plurality of image signals from the endoscope obtained with different amounts of light, and these pixel signals are combined and displayed on the monitor TV 18. In this example, in-vivo images obtained using three levels of light intensity are monitored with optimal shading.
It can be projected onto TV18. In other words,
A wide range inside the living body can be displayed on the monitor TV 18 with optimal shading without being limited by the photographing distance range.

Note that this invention is not limited to the above embodiment,
A configuration as shown in FIG. 3 may be used. That is, in this embodiment, the first image memory 20 and the second image memory 21 are connected to the write circuit 14 via the first switching circuit 22, and the first and second image memories 20, 21 have a first readout circuit 23 and a second readout circuit 24, respectively.
connected. The first and second readout circuits 23 and 24 are connected to the D-A via a second switching circuit 25.
In addition to being connected to the conversion circuit 17, the first and second switching circuits 22 and 25 are switched by a synchronizing signal from a synchronizing circuit 19.

According to such a configuration, the first image memory 2
While the pixel signals from the first to third ND filters 9a to 9c are being written to 0, the entire screen written to the second image memory 21 is read out by the second reading circuit 24, and the next At this point, the first and second switching circuits 22 and 25 are switched by the synchronization signal from the synchronization circuit 19, and the first image memory 20
The operation of the second image memory 21 is reversed. That is, according to this embodiment, writing and reading to one image memory 15 are not performed at the same time as in the above embodiment.

Further, in other embodiments, although not shown, there may be one readout circuit, and a second switching circuit may be provided between this readout circuit and the first and second image memories, but writing and reading may be performed. It can be done separately.

Furthermore, although three ND filters are provided in the rotary filter, any number of ND filters may be used as long as there are two or more, and the synchronization signal from the synchronization circuit can be used to control the TV camera, motor, writing circuit, switching circuit, and readout. It is clear that the circuit, switching circuit and monitor TV need not be synchronized.

As described above, the present invention takes an image obtained by an endoscope and converts it into an electric signal for each pixel.
The amount of light incident on this conversion means is sequentially switched by a light amount switching means, and those that meet appropriate conditions are extracted from each pixel signal obtained by the conversion means and combined. then 1
Since the images are displayed as one screen, it is possible to widen the range of light intensity differences that can be observed satisfactorily.
Therefore, a wide range can be displayed satisfactorily with appropriate shading without being subject to large restrictions on light intensity differences due to distances of photography. Furthermore, there is no need to control the output of the light source device or use a special light source, and the device can be simplified.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a plan view of the rotary filter, and FIG.
The figure is a block diagram showing another embodiment of the invention. 1...Endoscope, 8...Light source lamp, 11...
TV camera, 12...Discrimination circuit, 15, 20, 2
1... Image memory, 18... Monitor TV.

Claims (1)

[Claims] 1. A conversion means for dividing an image obtained by an endoscope into a plurality of pixels and converting each pixel into an electrical signal; and a light amount switching means for changing the amount of light incident on this conversion means; A discrimination circuit that discriminates the pixel signals obtained by the above-mentioned one conversion means in the light quantity switched by the light quantity switching means and selects those that meet a predetermined appropriate condition, and stores the pixel signals extracted by the discrimination circuit. 1. An image processing device for an endoscope, comprising: a storage device for storing the image information stored in the storage device; and a display device for synthesizing image information at each light amount stored in the storage device and displaying the resultant image as an image.