JP2001028709A - Electronic endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To display an excellent image by connecting an electronic endoscope even if a processor is different in the setting of a level of an image signal corresponding to lightness of a display device. SOLUTION: In the case the electronic endoscope has e.g. a new B type electronic scope 10 that a digital output level of a video signal to obtain lightness of 100 IRE of a display device is 200 and a conventional A type processor 12 that a digital output level of a video signal to obtain lightness of 100 IRE of the display device is 230, the electronic scope 10 is provided with a level conversion circuit 21, which matches the level of the video signal with a signal level of the processor 12. Thus, it is possible to connect the new electronic scope 10 to the old processor 12. Furthermore, the level conversion circuit may be placed in an analog signal processing area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic endoscope apparatus, and more particularly to a configuration of an electronic endoscope apparatus which can connect a processor apparatus and an electronic endoscope in which output levels of image signals do not match.

[0002]

2. Description of the Related Art Generally, an electronic endoscope apparatus is configured such that an electronic endoscope (electronic scope) having a CCD (Charge Coupled Device) as a solid-state image pickup device at a distal end thereof is connected to a processor device. For example, in this electronic scope, a digital video processor (DVP) converts an image signal (video signal) of the inside of the observed body imaged by the CCD into an image signal.
A certain amount of image processing such as amplification, white balance, gamma correction, etc. is performed using a processor, etc., and in the processor device, contour enhancement, insertion of character images, etc. are performed, and not only a television monitor but also an RGB monitor or a computer display. For example, the luminance signal and the color difference signal are converted into R (red), G (green), and B (blue) RGB signals.

[0003]

However, in recent years,
The level of the image signal for a predetermined level of the brightness of the image displayed on the TV monitor is made lower than the conventional level,
It has been proposed to prevent a high-brightness image from being whitened.

FIG. 6 is a graph showing two different processes for an output level of a video signal. FIG. 6A shows a process of a conventional type (referred to as an A type) electronic endoscope apparatus. (B) is a new type (B type)
This is the processing of the device. In the type A of FIG. 6A, the output level of the video signal from the electronic scope is a digital value. For example, 230 in the range of 0 to 255 indicates the brightness of the television monitor.
Engineers) value is set to match 100. Note that the average value is around 50 IRE.

On the other hand, in the type B shown in FIG.
The setting is made such that 200 within the same setting range matches the above 100 IRE. According to this, when compared with the case of the A-type, [spread values from 25 (M _A) to 55 (M _B)] becomes wider spacing M _B to the upper limit 255, the high-intensity image is crushed white This has the advantage of reducing Such B-type processing is performed not only on a TV monitor,
This is particularly effective when an endoscope image is displayed on various types of displays such as monitors of other types and computer displays.

However, in such a new type B electronic endoscope apparatus, there is no problem if the electronic scope is connected to the same type of processor apparatus, but the A type processor apparatus which has been conventionally used has no problem. Is connected, there is a problem that the image is displayed dark on the whole. Since the electronic scope or the processor device is not inexpensive, the usability is improved if a new electronic scope can be connected to the old type processor device for use.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to connect an electronic endoscope to a processor device having different settings of image signal levels with respect to the brightness of a display. An object of the present invention is to provide an electronic endoscope apparatus capable of displaying a good image.

[0008]

In order to achieve the above object, an electronic endoscope apparatus according to the first aspect of the present invention considers the brightness of an image signal obtained by an image sensor on a display. An electronic endoscope that performs image processing by performing predetermined signal processing on an image signal input from the electronic endoscope, and a level setting of the image signal with respect to the brightness of the display device is different from that of the electronic endoscope. A processor device, wherein the electronic endoscope has
A level conversion circuit that converts a level of an image signal processed in the electronic endoscope into a set level on the processor device side, and obtains information on a level setting of the processor device and switches an operation of the level conversion circuit. And a control circuit for controlling. According to a second aspect of the present invention, in the electronic endoscope, a level conversion circuit that performs the level conversion in an analog signal area is arranged.

According to the above arrangement, when it is determined that the processor device is of a different type, the level conversion circuit is enabled, and after the image signal output from the image pickup device has been subjected to a predetermined process, the signal level of the image signal is reduced. The level is converted into a level set on the processor device side by the level conversion circuit and output to the processor device. Accordingly, even if the processor device has a different image signal level setting, an electronic scope can be connected to perform good display processing, and an image with optimal brightness can be obtained.

According to the second aspect of the present invention, the level conversion is performed, for example, in the analog signal area before the digital signal processing. In this case, there is no quantization error generated in the digital processing. There is an advantage that reproduction of a fine image signal is improved.

[0011]

FIG. 1 shows the configuration of an electronic endoscope apparatus according to a first embodiment of the present invention.
A case where a new type B electronic endoscope (electronic scope) 10 is connected to a conventional type A processor device 12 will be described. First, the electronic scope 10 is provided with a CCD 13 at the distal end thereof via an objective optical system, a CCD driving circuit 14 for driving the CCD 13, and a light guide 15 for irradiating light from the distal end. This light guide 15 is connected to a light source device 16 in which a light source and a light amount aperture are arranged.

On the other hand, the CCD 13 has a correlated double sampling (CDS-Correlated Double Sampling) circuit 18, an A / D (analog / digital) converter 19, and a digital video processor (DVP-Digital Video Proces).
sor) 20 is arranged. In this DVP20, CCD
A luminance signal (Y) and a color difference signal (C) are formed by digital processing on the image signal (video signal) output from 13, and image processing such as amplification, white balance, and gamma correction is performed.

The level conversion circuit 2 is provided at the subsequent stage of the DVP 20.
The level conversion circuit 21 includes a conversion table shown in FIG. 2 and outputs the video signal (Y, C) output level output from the DVP 20 to the processor device 1.
2 is converted to the set level. For example, FIG.
As shown in the figure, the video signal level (maximum value 255)
Digital value 200 (714 mV in voltage value)
To 230 (821 mV in voltage value) and 100 (3
57 mV) is converted to 115 (410.5 mV) to 1.15 times, and the level conversion from the B type device to the A type device is performed.

Also, a microcomputer 23 that controls each circuit in an integrated manner.
And a ROM (read-only memory such as EEPR
OM) 24 are provided. The microcomputer 23 communicates with a microcomputer (to be described later) in the processor device 12 to output the video signal output level of the connected processor device 10, that is, the data or the processor of the level 230 corresponding to the display brightness 100 IRE. The ID information of the device 10 is acquired, and the level conversion is controlled. That is,
When the connected processor device 12 determines that level conversion is necessary for the A type, the level conversion circuit 21 is operated to perform the conversion, and when it is determined that the B type electronic scope is connected, Switching control is performed so that the conversion circuit 21 is not operated.

On the other hand, in the processor device 12, a mirror circuit 26 for inverting the image left and right, an outline emphasizing circuit (enhancer) 27, and a luminance signal (Y) and a color difference signal (C) are
(Red), G (green), and B (blue) signals, a color conversion circuit 28, a resolution conversion circuit 29 for adjusting to the resolution of the output side display, and a character for mixing characters such as patient information and imaging data. A mixing circuit 30 and a D / A converter 31 are provided. The analog video signal output from the D / A converter 31 is separated by an isolation 32 and a buffer circuit 3.
3 to a computer display (or other display device) or the like.

In this embodiment, the output of the resolution conversion circuit 29 is supplied to another resolution conversion circuit (not shown) and output to another RGB monitor, and the RGB signal is further converted to Y ( (Luminance) signal and C (color difference) signal and output to a television monitor. Of course, as the Y signal and the C signal, the color conversion circuit 28
The input signal to is available.

Further, a microcomputer 34 and a ROM 35 for controlling the above circuits are provided.
Processing information in the processor device 12, in this case, data of the signal level value 230 corresponding to the brightness IRE100 of the display or ID indicating the type of the processor device 12
Information is stored. Such information is transmitted by communication to the microcomputer 23 of the electronic scope 10 for controlling the operation of the level conversion circuit 21 described above.

A first example of the embodiment has the above-described configuration.
The operation will be described below. First, when the B-type electronic scope 10 is connected to the A-type processor device 12, the communication between the microcomputer 23 and the microcomputer 34 causes
Information on the level conversion read from the OM 35, for example, data of the level value 230 is transmitted to the microcomputer 23. When the information stored in the ROM 35 is ID data (indicating that the data is the A type),
From the D data, the output level value of the processor device 12 becomes 23
It is determined that it is 0. Then, the microcomputer 23 switches to operate the level conversion circuit 21.

On the other hand, the CCD 1 in the electronic scope 10
In 3, a video signal in the body to be observed is formed. The video signal is subjected to a clamping process or the like by the CDS circuit 18, converted into a digital signal, and subjected to various image processing by the DVP 20. A Y signal and a C signal are output. The Y signal and the C signal are supplied to the level conversion circuit 21. Here, the level values of the Y signal and the C signal are multiplied by 1.15 based on the conversion table shown in FIG. Into 115.

When the output of the level conversion circuit 21 is supplied to the processor 12, the video signal is inverted left and right,
After the outline emphasis processing is performed, the signals are converted into RGB signals (from the mirror circuit 26 to the color conversion circuit 28), and the character signals are mixed (the character mixing circuit 30). Is output to This B type electronic scope 10
In the video signal processed by the above, a brightness of 100 IRE is originally obtained at a level value of 200 as shown in FIG. 6B, but by the above conversion, a level value of 230 is obtained as shown in FIG. A brightness of 100 IRE can be obtained. Therefore, even when the B-type electronic scope 10 is connected to the A-type processor device 12, an image with good brightness can be displayed on a display such as a computer display, a television monitor, or the like without becoming dark.

The B-type electronic scope 10
Is connected to the B type processor device 12,
Similarly, based on the information obtained from the ROM (35), the level conversion circuit 21 does not operate, and predetermined processing is performed without performing level conversion. In this case, a good image can be provided without the high-luminance image being crushed white as compared with the related art.

FIG. 4 shows a configuration inside an electronic scope according to a second example of the embodiment. In the second example, a level conversion circuit is provided in an analog signal area in the same configuration as the first example. Things. That is, C of the electronic scope (10)
A level conversion circuit 37 for analog processing is provided between the CDS 18 and the A / D converter 19 arranged at the subsequent stage of the CD (13).
Is provided.

According to the second example, the level of the correlated double-sampled video signal is converted. This level conversion converts the B-type setting level to the A-type setting level, as in the first example. , As shown in FIG. Then, after being converted into a digital signal by the A / D converter 19, predetermined image processing is performed by the DVP 20, and at the same time, a Y signal and a C signal are supplied. These signals are supplied to the processor device 12 of FIG. Is done.

According to the configuration of the second example, the level conversion is performed in the analog signal area, and there is no quantization error caused by digital signal processing, and the reproducibility of fine signals can be improved. it can.

In the above-described embodiment, the level conversion circuits 21 and 37 are provided in the new B-type electronic scope 10 so that the level conversion circuits 21 and 37 can be connected to the old A-type processor device 12. Can be connected to the B-type processor device 12. In this case, for example, a level conversion circuit for converting the level value to 20/23 times is attached to the electronic scope by an adapter or the like.

FIG. 5 shows an example of the conversion table of the level conversion circuit in the above case. In this case, the digital value 230 indicating the video signal level is set to 200 and 115
Is converted to 20/23 times such as 100 to perform level conversion from the A type device to the B type device. This makes it possible to connect the A-type electronic scope to the B-type processor device 12 and display a good image.

[0027]

As described above, according to the present invention,
When a level conversion circuit is provided in the electronic scope and connected to a processor device having a different video signal level setting with respect to the brightness of the display, the level of the video signal processed inside the electronic endoscope is changed to the level on the processor device side. Because of the matching, even with a conventional processor device, it is possible to connect and use a new type of electronic scope and display a good image.

According to the second aspect of the present invention, since the level conversion is performed in the analog signal domain, there is an advantage that there is no quantization error caused by digital processing and the reproduction of a fine image signal is improved. is there.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an electronic endoscope apparatus according to a first example of an embodiment of the present invention.

FIG. 2 is a graph illustrating a conversion example of the level conversion circuit of the first example.

FIG. 3 is a graph showing the level and brightness (IRE) of a video signal obtained when a B-type electronic scope is connected to an A-type processor device in the first example.

FIG. 4 is a block diagram showing a partial configuration of an electronic scope according to a second example of the embodiment.

FIG. 5 is a graph showing an example of level conversion when an A-type electronic scope is connected to a B-type processor device in the embodiment.

FIG. 6 shows the relationship between the output level of a video signal and the brightness (IRE) in a conventional electronic endoscope device or the like, wherein FIG. 6A shows an example of a conventional A-type device, and FIG. It is an example of a B type device.

[Explanation of symbols]

10: electronic scope (B type), 12: processor device (A type), 13: CCD,
20: DVP, 21, 37: Level conversion circuit,
23, 34 ... microcomputer, 24, 35 ... ROM.

Claims (2)

[Claims] An electronic endoscope that performs image processing on an image signal obtained by an image sensor in consideration of brightness on a display, and a predetermined signal processing on an image signal input from the electronic endoscope. And a processor device in which the level setting of the image signal with respect to the brightness of the display device is different from the electronic endoscope, wherein the electronic endoscope has an image signal processed in the electronic endoscope. A level conversion circuit for converting the level of the processor device into a setting level on the processor device side, and a control circuit for acquiring information on the level setting of the processor device and switching and controlling the operation of the level conversion circuit. Electronic endoscope device. 2. The electronic endoscope apparatus according to claim 1, wherein the electronic endoscope includes a level conversion circuit that performs the level conversion in an analog signal domain.