JP2003153859A - Electronic endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic endoscope which is an electronic endoscope consisting of a solid-stage imaging element having built-in filters and does not require the bothersome formation of white balance correction data at every use of the electrode endoscope after a thermal sterilization treatment. SOLUTION: This electronic endoscope 10 is furnished with the solid-stage imaging element 16 for monitoring color facing of a color filter into which a color filter CF60 of the characteristics equal to those of a color filter CF18 of the solid-stage imaging element for photography is built, in order to monitor the degree of the deterioration by the color fading of the above color filter. The white balance correction data for correcting the gains for amplifying the image signals of the respective colors of the color image signals obtained from the solid-stage imaging element for photography is formed. The color filter CF18 of the solid-stage imaging element for monitoring the color fading of the color filter is illuminated with white light and the correction data for the white balance correction data is formed in accordance with the color information signal obtained from the solid-stage imaging element for monitoring the color fading of the color filter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic endoscope for use in an electronic endoscope system, which includes a solid-state image pickup device incorporating a color filter for obtaining an endoscopic image as a color image. The present invention relates to a plate-type electronic endoscope.

[0002]

2. Description of the Related Art In the electronic endoscope as described above, a solid-state image pickup device is provided on the distal end face side, and an imaging lens system is incorporated in the color filter. On the other hand, a light guide cable composed of an optical fiber bundle is inserted into the electronic endoscope, and its distal end is optically connected to an illumination lens provided on the distal end face of the electronic endoscope. It

The electronic endoscope system includes, in addition to the electronic endoscope, a video signal processing unit adapted to detachably connect the electronic endoscope. A light source device having a white lamp is provided in the video signal processing unit, and when the electronic endoscope is connected to the video signal processing unit, the proximal end side of the light guide cable is optically connected to the light source device. The front end of the distal end of the electronic endoscopic scope is connected, and the subject is imaged on the light receiving surface of the solid-state imaging device as an endoscopic image through the color filter. The color filter is composed of, for example, fine three primary color filter elements arranged in a mosaic pattern, and thus the endoscope is photoelectrically converted into one frame of three primary color image signals by the solid-state imaging device.

A video signal processing circuit is provided in the video signal processing unit, and the one-frame three-primary-color image signals read from the solid-state image pickup device are sequentially sent to the video signal processing circuit, where they are appropriately processed and then color video. A signal is output from the video signal processing circuit. The electronic endoscope system further includes a TV monitor device connected to the video signal processing unit, and a color video signal is sequentially sent from the video signal processing circuit to the TV monitor device.
In the V monitor device, the endoscopic image is reproduced and displayed as a color image based on the color video signal. In short, by inserting the electronic endoscope into the human body, the subject inside the human body can be observed as a color endoscope image on the TV monitor device.

The electronic endoscope is detachably connected to the video signal processing circuit because there are various types of electronic endoscopes.

By the way, since the individual solid-state image pickup devices used in various electronic endoscopes have different spectral sensitivity characteristics, when the individual electronic endoscopes are used, their color is different. In order to reproduce an endoscopic image on a TV monitor device with proper color balance, the gain (amplification degree) of each color image signal of the three primary color image signals for one frame read from the solid-state image sensor is corrected. Then, the process of adjusting the image signal level of each color, that is, the white balance correction process must be performed. Of course, the white balance correction data for correcting the gain of the image signal of each color of the three primary color image signals is different for each electronic endoscope scope, so white balance correction is performed when using each electronic endoscope scope. Work to create data is required.

That is, in order to create the white balance correction data, for example, the distal end of the electronic endoscope is inserted into a cylindrical enclosure whose inside is coated with a standard white color, and one frame obtained at this time is inserted. The image signal levels of the respective three primary color image signals are compared, and a coefficient for eliminating the signal level difference between the image signals of the three primary colors is created as white balance correction data. When the electronic endoscope is actually used, each of the three primary color image signals obtained from the solid-state image pickup device is multiplied by the coefficient based on the white balance correction data, so that the color endoscopy image is displayed on the TV monitor with proper color balance. It will be reproduced on the device.

It is very troublesome to create the white balance correction data each time each electronic endoscope is used. Therefore, conventionally, an appropriate nonvolatile memory is mounted on each electronic endoscope.
White balance correction data is written and stored in the nonvolatile memory. In short, when the electronic endoscope is used, the white balance correction data is read from the non-volatile memory, and the gain of each color signal of the three primary color image signals is corrected by the coefficient based on the white balance correction data. Thus, it is not necessary to perform the work of creating white balance correction data each time each electronic endoscope is used. Note that the spectral sensitivity characteristics of the solid-state image sensor of the electronic endoscope scope change with time, and the color temperature of the white lamp of the light source device in the video signal processing unit also changes with time. Needs to be updated in a timely manner.

[0009]

Now, after the electronic endoscope is used by one patient, it is necessary to disinfect and sterilize it in order to use the electronic endoscope again. . As a method of disinfection and sterilization, a method of immersing the electronic endoscope in a disinfectant solution and a method of putting the electronic endoscope in an autoclave and sterilizing by heating are known. Heat sterilization is easier than sterilization using a disinfectant, and heat sterilization is becoming the mainstream in recent years.

However, as a problem of heat sterilization, it has been pointed out that the color filter incorporated in the solid-state image pickup element may be deteriorated by heating due to heating. Discoloration deterioration of the three primary color filter elements due to heating is not uniform for each individual color, and the color balance of the color endoscopic image reproduced on the TV monitor device is destroyed each time the heating and sterilization process is performed. In order to prevent such a loss of color balance, it is necessary to always create white balance correction data when using the electronic endoscope after heat sterilization. Therefore, when the heat sterilization process is introduced for the sterilization of the electronic endoscope, it becomes meaningless to store and hold the white balance correction data in the nonvolatile memory as described above.

In short, if it is attempted to avoid creating white balance correction data every time the electronic endoscope is used, it is necessary to perform disinfecting and sterilizing treatment with a troublesome disinfecting solution, and also easy heat sterilizing treatment is introduced. This means that it is necessary to create troublesome white balance correction data each time the electronic endoscope is used.

Therefore, an object of the present invention is to provide an electronic endoscope having a solid-state image pickup device incorporating a color filter for obtaining an endoscopic image as a color image, the electronic endoscope after heat sterilization. An object of the present invention is to provide an electronic endoscope scope that does not need to create troublesome white balance correction data each time the scope is used.

[0013]

An electronic endoscope according to the present invention comprises a solid-state image pickup device for photographing which incorporates a color filter in order to obtain an endoscopic image as a color image. Solid state image sensor for color filter fading monitoring, which incorporates a color filter having the same characteristics as the color filter in order to monitor the degree of fading deterioration of the color filter, and irradiates the color filter of the solid state image sensor for monitoring with white light. White light irradiating means, white balance correction data creating means for creating white balance correction data for correcting gain when amplifying the image signal of each color of the color image signal obtained from the solid-state imaging device for photographing, and white Color information obtained from a memory means for storing balance correction data and a solid-state image sensor for color filter fading monitoring when illuminating a white light source Those formed by and a correction data generating means for generating a correction data for white balance correction data based on the issue.

The electronic endoscope according to the present invention further corrects the white balance correction data on the basis of the correction data created by the correction data creating means to white balance a color image signal obtained from the solid-state image pickup device for photographing. A white balance processing unit that performs a correction process may be provided.

In the preferred embodiment of the present invention, the correction data creating means is also operated each time the white balance correction data creating means is operated to create the correction data. To be done.

Further, in a preferred embodiment of the present invention, the correction data creating means is operated and the correction data is updated each time the electronic endoscope is used.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of an electronic endoscope according to the present invention will be described with reference to the accompanying drawings.

First, referring to FIG. 1, an entire electronic endoscope system using the electronic endoscope according to the present invention is schematically shown as a block diagram. An electronic endoscope according to the present invention is generally indicated by reference numeral 10, and the electronic endoscope system is adapted to be removably connected to the electronic endoscope 10. The video signal processing unit (so-called processor) 12 and the TV monitor device 14 connected to the video signal processing unit 12.

As described above, the electronic endoscope scope 10 is detachably connected to the video signal processing unit 12 in the electronic endoscope scope 1.
This is because 0 has various types. For example,
Typical examples of the electronic endoscope 10 include a bronchoscope, a stomach scope, and a large intestine scope. In short, the video signal processing unit 12 is shared by various types of electronic endoscope scopes.

The electronic endoscope 10 comprises an operating section 10A having a rigid structure, a flexible body inserting section 10B integrated with the operating section 10, and a signal cable 10C extending from the operating section 10A. . A connector 10D is attached to the tip of the signal cable 10C, and the electronic endoscope scope 10 is detachably connected to a socket (not shown) on the video signal processing unit 12 side via the connector 10D.

The operation section 10A of the electronic endoscope 10 is provided with a manual handle (not shown) for remotely controlling the movement of the tip of the body insertion section 10B and various switches. As a switch particularly related to this embodiment, there is a switch used when executing the creation of the white balance correction data, and this switch is indicated by reference numeral 16 in FIG. 1. In addition, the solid-state imaging device 1 is provided at the distal end of the body insertion portion 10B of the electronic endoscope 10.
8 (solid-state imaging device for photographing) is provided, and the solid-state imaging device 18 is composed of, for example, a CCD (charge-coupled device) imaging device. Although not shown in FIG. 1 in order to avoid complication of the drawing, an appropriate color filter is incorporated in the light-receiving surface of the CCD image pickup device 18, and the distal end surface of the electronic endoscope scope 10 has a color filter. A suitable imaging lens (not shown) is provided for imaging the subject on the color filter.

Within the electronic endoscope scope 10, a CCD drive signal transfer line 20 for transferring a read signal to the CCD image sensor 18 and an image signal transfer line for transferring a series of color pixel signals read from the CCD image sensor 18. 22 extends, and these transfer lines 20 and 22 are connected to a scope-side processing circuit 24 provided in the connector 10D. Printed circuit board (not shown) in connector 10D
And the scope-side processing circuit 24 is mounted on the printed circuit board. The printed circuit board is also provided with a series of pin-type contacts, and these pin-type contacts are sheath-type contacts of a socket on the side of the video signal processing unit 12 when the electronic endoscope scope 10 is connected to the video signal processing unit 12. Connected to.

Further, a light guide cable 26 composed of an optical fiber bundle extends in the electronic endoscope 10 and its distal end is connected to an illumination lens (not shown) provided on the end face of the body inserting section 10B. It is optically connected, and its proximal end is optically connected to an optical connection adapter 28 protruding from the connector portion 10D.

A print control circuit board is provided in the video signal processing unit 12, and a system controller 30, a timing controller 32 and a video signal processing circuit 34 are mounted on the print control circuit board. The system controller 30, the timing controller 32, and the video signal processing circuit 34 are appropriately connected to each other via a control bus, a signal bus, or the like.

In this embodiment, the system controller 3
0 is composed of a microcomputer. That is, the system controller 30 is a central processing unit (CPU),
Programs for executing various routines, read-only memory (ROM) for storing constants, etc., writable / readable memory (RAM) for temporarily storing data, etc.
It includes an input / output interface (I / O) and controls the overall operation of the electronic endoscope system. Further, as shown in FIG. 1, a keyboard 31 is connected to the system controller 30, and various command signals and the like are input via the keyboard 31 by an operator as necessary. In addition, the switch 1 is assigned to a predetermined function key on the keyboard 31.
It is also possible to provide the same function as 6 and a function for executing the creation of white balance correction data.

The timing controller 32 is operated under the control of the system controller 30. Control clock pulses of various frequencies are output from the timing controller 32, and various operation timings in the electronic endoscope system are generated in accordance with these control clock pulses. Is controlled. For example, the video signal processing circuit 34 is operated according to various control clock pulses output from the timing controller 32 as described later.

A light source device 36 is further provided in the video signal processing unit 12, and when the connector section 10D of the electronic endoscope 10 is connected to the video signal processing unit 12, the optical connection adapter 28 becomes the light source device 36. Optically connected. More specifically, as shown in FIG. 2, the light source device 3
6, a white lamp 38 such as a halogen lamp or a xenon lamp is provided, and a condenser lens 40 and a diaphragm 42 are sequentially arranged between the white lamp 38 and the end surface of the optical connection adapter 28. The condenser lens 40 is provided to collect the white light from the white lamp 40 on the end surface of the optical connection adapter 28, and the diaphragm 42 appropriately adjusts the incident light amount of the white light on the end surface.

As is apparent from FIG. 2, the light source device 36 is provided with a power supply circuit 44 for the white lamp 38, and the power supply circuit 44 is appropriately operated under the control of the system controller 30. Further, the light source device 36 is provided with an actuator 46 for operating the diaphragm 42, and the actuator 46 is operated by the diaphragm control circuit 48, and the diaphragm control circuit 48 is appropriately operated under the control of the system controller 30. In short, the aperture control circuit 4
The optical connection adapter 28 is operated by operating the actuator 46 by 8 to appropriately adjust the opening degree of the diaphragm 42.
Amount of white light incident on the end face of the light guide, that is, the light guide cable 2
The amount of emitted illumination light from the distal end surface of 6 is controlled. The aperture of the diaphragm 42 is controlled in a known manner so that the display screen of the TV monitor device 14 always has a constant brightness, and the control manner is generally called automatic light control.

Thus, the front of the distal end of the body insertion portion 10 is illuminated with the illumination light emitted from the distal end surface of the light guide cable 26 through the illumination lens. Therefore, when the body insertion part 10B of the electronic endoscope 10 is inserted into the body of the patient, the inside of the body of the patient is illuminated, and at this time, the subject, that is, the internal tissue OB (FIG. 1) is CC-illuminated by the imaging lens.
An image is formed as an endoscopic image on the light receiving surface of the D image pickup device 18 through the color filter.

Referring to FIG. 3, there is shown a detailed block diagram of the scope-side processing circuit 24 provided in the connector 10D. As shown in FIG. 3, the scope-side processing circuit 24 is provided with a scope-side controller 50. . Like the system controller 30, the scope-side controller 50 is also composed of a microcomputer. That is, the scope-side controller 50 is a central processing unit (CPU), a program for executing various routines, a read-only memory (ROM) that stores constants, and a writable / readable memory that temporarily stores data and the like. (RAM) and input / output interface (I / O) are included.

Further, the scope side processing circuit 24 has a DSP.
(digital signal processor) 52 is provided, and this DS
P52 is operated under the control of the scope-side controller 50. The DSP 52 is connected to the CCD image pickup device 18 via a CCD driver 54 and an analog / digital (A / D) converter 56. That is, the CCD image pickup device 18 and C
The CD driver 54 is connected by the CCD drive signal transfer line 20, and the CCD image pickup device 18 and the A / D converter 5 are connected.
6 is connected to the image signal transfer line 22.

In FIG. 3, a color filter incorporated in the light receiving surface of the CCD image pickup device 18 is indicated by reference numeral CF ₁₈ , and in the present embodiment, the color filter CF ₁₈ is a fine three-primary color filter element, that is, a red filter element, The green filter elements and the blue filter elements are arranged in a mosaic pattern. Therefore, the endoscopic image formed on the light receiving surface of the CCD image pickup device 18 through the color filter CF ₁₈ contains image information of the three primary colors, and this endoscopic image is converted into a three-primary-color image signal for one frame by the CCD image pickup device 18. It is photoelectrically converted.

In order to read out one frame of three primary color image signals from the CCD image pickup device 18, a series of CCD drive signals are output from the CCD driver 54 to the CCD image pickup device 18, and the output timing of the series of CCD drive signals is set. It is controlled by the DSP 52. The three primary color image signals sequentially read from the CCD image pickup device 18 are converted into three primary color digital image signals by the A / D conversion 56, that is, a red digital image signal R, a green image signal G and a blue image signal B. (R, G, B) is D
DSP5 after undergoing various image processing by SP52
2 to the video signal processing circuit 34 in the video signal processing unit 12.

The reading of one frame of three primary color image signals from the CCD image pickup device 18 is carried out at predetermined time intervals according to the TV image reproduction system adopted in the electronic endoscope system. For example, the NTSC system is used. When adopted, the reading of the three primary color image signals is 30 times per second, and when the PAL system is adopted, the reading of the three primary color image signals is 25 times per second.

Among the various image processes performed by the DSP 52, the image processing particularly related to the present invention is a white balance process. In white balance processing,
The gain of the image signal of each color of the three primary color digital image signals is corrected by the white balance correction data,
As a result, proper color balance can be obtained between the three primary color digital image signals. The white balance processing will be described later in detail.

As shown in FIG. 3, the scope side processing circuit 2
4 is a nonvolatile memory such as an EEPROM (ele
ctrically erasable programmable read-only memory)
The EEPROM 58 stores various information data unique to the electronic endoscope 10.
White balance correction data is an example of the information data that is particularly relevant to the present invention. When the three primary color image signals are read from the CCD image pickup device 18, the scope-side controller 50 reads the white balance correction data from the EEPROM and outputs it to the DSP 52.
The DSP 52 stores the white balance correction data in its built-in memory. Of course, the DSP 52 performs the above-mentioned white balance processing based on the white balance correction data.

As described above, the electronic endoscope scope 1
When 0 is subjected to the heat sterilization treatment, the color filter CF ₁₈ of the CCD image pickup device 18 may be deteriorated by fading. In order to monitor the degree of fading deterioration of the color filter CF ₁₈ , the scope-side processing circuit 24 includes a monitoring CCD image pickup device 60.
(Color filter fading monitoring solid-state image sensor) is provided, and the color filter C is provided on the light receiving surface of the monitoring CCD image sensor 60.
A color filter CF ₆₀ having the same characteristics as F ₁₈ is incorporated. The monitoring CCD image pickup device 60 is used not as an image pickup device but as a detection device for detecting the color deterioration of the color filter CF ₆₀ , and has a smaller number of pixels than the photographing CCD image pickup device 18. It is supposed to be.

As shown in FIG. 3, a white LED is used as a white light source in the color filter CF ₆₀ of the monitoring CCD image pickup device 60.
(light emitting diode) 62 is opposed to the white LED 62.
The ED power supply circuit 64 is operated under the control of the scope-side controller 50. That is, the scope side controller 5
When an ON signal is output from 0 to the LED power supply circuit 64, the white LED 62 is turned on in the LED power supply circuit 64, and the emitted light of the white LED 62 passes through the color filter CF ₆₀ and is received by the monitoring CCD image pickup device 60. The surface is illuminated.
That is, a mosaic image of the color filter CF ₆₀ is projected on the light receiving surface of the monitoring CCD image pickup device 60, and the mosaic image is photoelectrically converted as one frame of three primary color image signals.

On the other hand, the monitoring CCD image pickup device 60 is a CCD
It is connected to the scope-side controller 50 via the driver 66, the A / D converter 68, and the RGB signal generation circuit 69. The CCD driver 66 outputs a series of CCD drive signals to the monitoring CCD image pickup element 60 in order to read out one frame of three primary color image signals from the monitoring CCD image pickup element 60, and the output timing of the series of CCD drive signals. Are controlled by the scope-side controller 50.
The three primary color image signals sequentially read from the monitoring CCD image pickup device 60 are A / D converted 68 and RGB signal generation circuit 69.
After being converted into a three-primary-color digital image signal by, it is taken into the scope-side controller 50. The scope-side controller 50 is used when the correction data for correcting the above-mentioned white balance correction data is created after the three primary color data image signals from the monitoring CCD image sensor 60 are appropriately processed. The creation of such correction data will be described in detail later.

The electronic endoscope scope 10 has its connector 1
When connected to the video signal processing unit 12 by OD, the DSP 52 is connected to the video signal processing circuit 34, and the scope-side controller 50 is connected to the system controller 30. Although not shown in FIG. 1,
The video signal processing unit 12 is provided with a power supply device for supplying power to various devices and circuit boards inside the video signal processing unit 12. When the electronic endoscope scope 10 is connected to the video signal processing unit 12 by its connector 10D, The scope-side processing circuit 24 also receives power from the power supply device through a power supply line (not shown).

Referring to FIG. 4, a detailed block diagram of the video signal processing circuit 34 of the video signal processing unit 12 is shown. As shown in the figure, the video signal processing circuit 34 is provided with a video signal preprocessing circuit 70. In the video signal preprocessing circuit 70, the three primary color digital image signals (R, G, B) sent from the DSP 52. Various kinds of processing are performed on the three primary color digital image signals (R, G, B) and a luminance signal Y and two color difference signals (RY) and (BY). ) And conversion processing to convert. The various processes in the video signal preprocessing circuit 70 are performed in accordance with the control clock pulse output from the timing controller 32.

The video signal processing circuit 34 has a memory 7
2 is provided, and the memory 72 has a first memory area 7
2 ₁ , 72 ₂ and 72 ₃ are included. Luminance signal Y and two color-difference signals sequentially outputted from the video signal pre-processing circuit 70 (R-Y) and (B-Y) and the first respectively the second and the third memory region 72 _1, 72 ₂ and Once written in 72 ₃ , the writing of the luminance signal and the two color difference signals into these memory areas is performed in accordance with the writing clock pulse output from the timing controller 32.

[0043] On the other hand, the first, and sequentially writes the second and third memory areas 72 _1, 72 ₂ and 72 ₃ in the luminance signal Y and two color difference signals (R-Y) and (B-Y) While on the other hand, on the other hand, the first, second and third memory areas 7
From 2, ₁ , 72 ₂ and 72 ₃ , the related luminance signal Y
And the two color difference signals (RY) and (BY) are simultaneously read at a predetermined timing, and the reading of the luminance signal and the two color difference signals from those memory areas is also output from the timing controller 32. It is performed according to a clock pulse.

As shown in FIG. 4, the video signal processing circuit 34
Is further provided with a video signal post-processing circuit 74. In the video signal post-processing circuit 74, the luminance signal Y read from the memory 72 and two color difference signals (RY) and (BY) are provided.
Various processes are performed on and, and one of the main processes is a conversion process for returning the luminance signal and the two color difference signals to the original three primary color image signals. Such three primary color image signals (R, G, B) are converted into three primary color analog image signals by digital / analog (D / A) conversion included in the video signal post-processing circuit 74, and then red video of the component video signals. The video signal post-processing circuit 74 outputs the signal component R, the green video signal component G, and the blue video signal component B. On the other hand, the composite sync signal component SYNC of the component video signal is generated by the timing controller 32 and output from the video signal post-processing circuit 74 together with the three primary color video signal components (R, G, B). The component video signal output from the video signal post-processing circuit 74 is sent to the TV monitor device 14, and the TV monitor device 14 reproduces an endoscope image based on the component video signal.

Further, in the video signal post-processing circuit 74, an S video signal (Y / C) and a composite video signal C may be created in addition to the above-mentioned component video signal. It is appropriately output from the circuit 74. The video signals can be used for recording an endoscopic image by a video tape recorder, for example.

As in the case of the video signal pre-processing circuit 70, various processes in the video signal post-processing circuit are also performed according to the control clock pulse output from the timing controller 32.

The white balance processing described above is CC
This is a process for correcting the deviation of the spectral sensitivity characteristic of the D image pickup device 18. For example, the CCD image pickup device 18 shows the best sensitivity to red light, then the intermediate sensitivity to green light, and the blue light. This is a process of correcting the gain when amplifying each of the red image signal, the green image signal, and the blue image signal so as to eliminate the sensitivity difference when the worst sensitivity is exhibited. Specifically, for example, when the gain of the green image signal is used as a reference, the gain of the red image signal is reduced so as to cancel the sensitivity difference between the red light and the green light, and the gain of the blue image signal is reduced. It is increased so as to cancel out the difference in sensitivity between blue light and green light. As described above, the white balance correction data for correcting the gains of the three primary color image signals is stored in the EEPROM.
58 in advance, and in the DSP 52, the EEPROM 5
White balance processing is performed on the basis of the white balance correction data read from No. 8.

Referring to FIG. 5, the scope side processing circuit 2
4 shows a flowchart of a white balance correction data creation processing routine executed by the scope-side controller 50 of FIG.

The white balance correction data generation processing routine is executed by operating the switch 16 or a predetermined function key on the keyboard 31 while the electronic endoscope system is in an operable state. That is, when the switch 16 is operated while the electronic endoscope system is in an operable state, an execution command signal for the white balance correction data creation processing routine is output to the scope-side controller 50, and a predetermined signal on the keyboard 31 is output. When the function key is operated, a white balance correction data creation processing routine execution command signal is first output to the system controller 30, and then the execution command signal is sent to the scope-side controller 50.

In addition, the switch 16 or the keyboard 3
Before operating a predetermined function key on 1, the predetermined preparation work is required. That is, first, the electronic endoscope scope 10
Is connected to the video signal processing unit 12, and then the power switch of the video signal processing unit 12 is turned on, whereby the electronic endoscope system becomes operable. In such an operable state, the body insertion portion 10B of the electronic endoscope 10 is inserted into a cylindrical enclosure body tube (not shown) whose inside is coated with a standard white color, whereby the CCD image sensor 18 receives light. The reference white subject is the color filter C on the surface.
It is imaged through F ₁₈ .

When the switch 16 and a predetermined function key on the keyboard 31 are operated after the above preparatory work is completed, the execution of the white balance correction data generation processing routine shown in FIG. 5 is started.

First, in step 501, one frame of the three primary color digital image signals is output from the A / D converter 56 to the DS.
It is fetched by the scope-side controller 50 via P52, and at this time, no processing is performed on the one-frame three-primary-color digital image signal. Next, at step 502, the average gains pg _R , pg _G, and p of the red digital image signals of the three-primary-color digital image signals for one frame.
g _B is calculated. That is, the average gain pg _R is the sum of all the gains of the red digital pixel signals for one frame and divided by the total number of pixels of the red digital image signal, and the average gain pg _G is the green for one frame. It is the sum of all the gains of the digital pixel signals and divided by the total number of pixels of the green digital image signal, and the average gain pg
_B is the sum of all the gains of the blue digital pixel signal for one frame and divided by the total number of pixels of the blue digital image signal.

In step 503, the white balance correction data (coefficients) W _R , W _G and W _B are obtained by the following arithmetic expression. _{W R = pg G / pg R} W G = pg G / pg G W B = pg G / pg B That is, in this embodiment, the average gain pg of the green image signal
_G is used as the reference value, and thus the white balance correction data W _G (coefficient) for the green data image signal is set to “1”, and the white balance correction data W _R (coefficient) for the red data image signal is red. A ratio of the average gain pg _G of the green image signal to the average gain pg _R of the data image signal, and similarly, the white balance correction data W _B (coefficient) for the blue data image signal is the average gain pg _{B of the} blue data image signal. To the average gain pg _G of the green image signal.

In step 504, the white balance correction data W _R , W _G and W _B are respectively stored in the EEPROM 58.
If the white balance correction data of the previous time is stored in the predetermined address, the white balance correction data of the previous time is updated by the white balance correction data of this time.

The creation of the white balance correction data described above is well known in the art, and when the electronic endoscope system is actually used, the digital image signal of each color output from the A / D converter 56. the signal level of the corresponding white balance correction data _{(W R, W G, W} B) multiplied by, would thereby reproduce the endoscopic image of the TV monitor 14 can be performed in a proper color balance.

According to the present invention, when the white balance correction data is created or updated, the following step 50 is always performed.
A process consisting of 5 to 513 is performed.

In step 505, the white LED 62 is turned on, so that the light receiving surface of the monitoring CCD image pickup device 60 is irradiated with white light through the color filter CF ₆₀ . Then, in step 506, the CCD driver 6
6, the A / D converter 68 and the RGB signal generation circuit 69 are operated, whereby the three-primary-color image signal for one frame is read at appropriate time intervals, and the one-frame three-primary-color image signal is A / D. The converter 68 and the RGB signal generation circuit 69 convert one frame of the three primary color image signals into one frame of the three primary color digital image signals.

At step 507, it is judged whether or not a predetermined time has elapsed. In addition, white LED is used for this predetermined time.
The light emitting state of 62 is stable and the CCD image pickup device 60 for monitoring
The time until the reading of the three primary color image signals for one frame from is stabilized is appropriately set.

When the elapse of a predetermined time is confirmed in step 507, the process proceeds to step 508, where the A / D converter 6
Three primary color digital image signals for one frame from 8 are fetched by the scope-side controller 50. Then
In step 509, the average gain mg _R , m of the red digital image signal of the three primary color digital image signals for one frame is calculated.
g _G and mg _B are calculated. That is, the average gain mg _R is the sum of all the gains of the red digital pixel signals for one frame and divided by the total number of pixels of the red digital image signal, and the average gain mg _G is the green gain for one frame. It is the sum of all the gains of the digital pixel signals and divided by the total number of pixels of the green digital image signal. The average gain mg _B is the sum of all the gains of the blue digital pixel signals for one frame. Is divided by the total number of pixels of the blue digital image signal.

The average gains mg _R , mg _G and mg _B
Represents the fading state of each of the red color filter element, the green color filter element and the blue color filter element of the current color filter CF ₆₀ , and is therefore data representing the respective fading state of the color filter CF ₁₈ having the same characteristics as the color filter CF _60. It is used as described below.

At step 510, the average gain mg _R ,
mg _G and mg _B are Lmg _R , Lmg _G and Lmg, respectively.
Replaced by _B. Then proceed to step 511,
Therefore, the average gains Lmg _R , Lmg _G, and Lmg _B are stored at predetermined addresses in the EEPROM 58, respectively. The average gains Lmg _R , Lmg _G, and Lmg _B are average gains (mg _R , mg _G , m obtained when the electronic endoscope 10 is used next time, as described later.
g _B ), the initial letter “L” of English “LAST” is added in the meaning of the previous average gain.

In step 512, the white LED 62 is turned off, and then in step 513, the CCD driver 6
6 and the operation of the A / D converter 68 are stopped. Thus, this routine ends.

After the electronic endoscope 10 is used by one patient, the electronic endoscope is removed from the video signal processing unit 12, and then the electronic endoscope 10 is used.
Will undergo disinfection and sterilization. If the electronic endoscope 10 is put in an autoclave and sterilized by heating, the color filter CF ₁₈ incorporated in the image pickup CCD image pickup device 18 may undergo fading deterioration due to heating as described above. At this time, since the color filter CF ₆₀ of the monitoring CCD image pickup device 60 has the same characteristics as the color filter CF ₁₈ of the image pickup CCD image pickup device 18, the color filter CF ₆₀ also fades to the same extent as the color filter CF _18. Will suffer degradation.

The degree of fading deterioration of each color filter element of the color filters (CF ₁₈ , CF ₆₀ ) is different, and therefore, when the electronic endoscope 10 is once subjected to the heat sterilization treatment, the electronic endoscope 10 is subjected to heat sterilization. when is used, but is required to perform anew the creation of the white balance correction data, but according to the present invention, the degree of fading deterioration of color filter CF ₆₀ is detected by the monitoring CCD imager 60, As a result, the white balance correction data is properly corrected, so that it is not necessary to create the white balance correction data again even when the electronic endoscope 10 is subjected to the heat sterilization process.

Referring to FIGS. 6 and 7, a white balance correction data correction processing routine is shown. The white balance correction data correction processing routine is a part of the initialization routine executed by the scope-side controller 50, and is executed only once when the power switch of the video signal processing unit 12 is turned on. Is.

In step 601, the white LED 62 is turned on, whereby the light receiving surface of the monitoring CCD image pickup device 60 is irradiated with white light through the color filter CF ₆₀ . Next, in step 602, the CCD driver 66
And the A / D converter 68 is operated to read the one-frame three-primary-color image signal at appropriate time intervals, and the one-frame three-primary-color image signal is read by the A / D converter 68 for one-frame. The three primary color image signals are converted into one frame of three primary color digital image signals.

At step 603, it is judged whether or not a predetermined time has elapsed. Note that, as in step 507 of the white balance correction data creation processing routine shown in FIG. 5, the white LED 62 has a stable light emission state for the predetermined time and the one frame of three primary color image signals is read from the monitoring CCD image pickup device 60. Is appropriately set as the time until it stabilizes.

When the elapse of a predetermined time is confirmed in step 603, the process proceeds to step 604, where the A / D converter 6
Three primary color digital image signals for one frame from 8 are fetched by the scope-side controller 50. Then
In step 605, the average gain mg _R , m of the red digital image signal of the three primary color digital image signals for one frame
g _G and mg _B are calculated.

At step 606, the previous average gain L
mg _R , Lmg _G, and Lmg _B are read from the EEPROM 58, and then, in step 607, the following calculation is performed. _{RT R = mg R / Lmg R} RT G = mg G / Lmg G RT B = mg B / Lmg B That is, the ratio RT _R of this average gain mg _R to the average gain Lmg _R previous, the average gain of the previous Lmg _G the ratio RT _B of this average gain mg _B obtained to the average gain Lmg _B ratio RT _G and previous current average gain mg _G against.

If a color filter (CF ₁₈ , CF ₆₀ )
If each color filter element of is subject to fading deterioration, its light transmittance increases, so the average gain (mg _R , m
g _G , mg _B ) is the previous average gain (Lmg _R , Lmg _G ,
Lmg _B ), which is why each ratio (RT _R , R
T _G , RT _B ) can be 1 or more.

At step 608, the following calculation is performed. _{Δg R = │mg R -Lmg R │} Δg G = │mg G -Lmg G │ Δg B = │mg B -Lmg B │ words, this average gain _{(mg R, mg G, mg} B) and the average of the previous gain _{(Lmg R, Lmg G, Lmg} B) gain difference between Delta] g _R, the absolute value of Delta] g _R and Delta] g _R are determined.

At step 609, it is judged if the gain difference Δg _R is larger than a predetermined threshold value TH. Δg _R
> TH, that is, color filters (CF ₁₈ , CF ₆₀ ).
When fading deterioration is recognized in the red filter element of, the process proceeds to step 610, where the white balance correction data W _R for the red digital image signal is corrected by the following equation. Where _{W R = W R / RT R} , RT R is the corrected data for correcting the white balance correction data W _R, by dividing the white balance correction data W _R in this corrected data RT _R,
It is possible to reduce the gain of the color filter CF ₁₈ , which has been increased by the amount of fading of the red color filter element.

On the other hand, when Δg _R ≦ TH in step 609, that is, when the red filter element of the color filter (CF ₁₈ , CF ₆₀ ) shows no fading deterioration, step 61
Bypassing 0, the process proceeds to step 611.

At step 611, it is judged if the gain difference Δg _G is larger than a predetermined threshold value TH. Δg _G
> TH, that is, color filters (CF ₁₈ , CF ₆₀ ).
When fading deterioration is recognized in the green color filter element of, the process proceeds to step 612, where the white balance correction data W _G for the green color digital image signal is corrected by the following equation. Here _{W G = W G / RT G} , RT G is a correction data for correcting the white balance correction data W _G, by dividing the white balance correction data W _G in this corrected data RT _G,
It is possible to reduce the gain of the color filter CF ₁₈ , which has been increased by the amount of fading of the green color filter element.

On the other hand, when Δg _G ≦ TH in step 611, that is, when the green filter element of the color filter (CF ₁₈ , CF ₆₀ ) shows no fading deterioration, step 61
2 is bypassed and the process proceeds to step 613.

At step 613, it is judged if the gain difference Δg _B is larger than a predetermined threshold value TH. Δg _B
> TH, that is, color filters (CF ₁₈ , CF ₆₀ ).
When fading deterioration is recognized in the blue filter element of, the process proceeds to step 614, where the white balance correction data W _B for the blue digital image signal is corrected by the following equation. Here _{W B = W B / RT B} , RT B is the correction data for correcting the white balance correction data W _B, by dividing the white balance correction data W _B at the correction data RT _B,
It is possible to reduce the gain of the color filter CF ₁₈ , which is increased by the amount of fading of the blue filter element.

On the other hand, when Δg _B ≦ TH in step 613, that is, when the blue filter element of the color filter (CF ₁₈ , CF ₆₀ ) shows no fading deterioration, step 61
4 is bypassed and the process proceeds to step 615.

At step 615, the current average gain m
g _R , mg _G and mg _B are replaced with Lmg _R , Lmg _G and Lmg _B respectively. Then proceed to step 616, where the average gains Lmg _R , Lmg _G and Lmg _B.
Are stored at predetermined addresses in the EEPROM 58 and updated.

In step 617, the white LED 62 is turned off, and then in step 618, the CCD driver 6
6 and the operation of the A / D converter 68 are stopped. Thus, this routine ends.

Of course, when the electronic endoscope 10 is used again, the white balance correction data correction processing routine of FIG. 6 and FIG. 7 is executed, and at this time, step 61
Average gain Lm stored in the EEPROM 58 at 6
g _R, using Lmg _G and Lmg _B, the white balance correction data _{(W R, W G, W} B) because is corrected if necessary, always proper white balance processing in DSP52 may be performed.

Further, every time the white balance correction data is created (FIG. 5) regularly, the average gain mg _R representing the fading state of the color filter CF ₆₀ of the monitoring image sensor 60,
Since mg _G and mg _B are determined anew, it can be performed without significant errors for correction of the white balance correction data _{(W R, W G, W} B).

In the above-described embodiment, various image processes including the white balance process are executed by the scope side processing circuit 2.
It is supposed to be done by DSP 52 of 4
It is also possible to provide 52 in the video signal processing circuit 34 and perform the various image processes on the video signal processing circuit 34 side in the video signal processing unit 12. Of course, in that case, the scope side controller 50 causes the EEPR
White balance correction data read out from _{OM58 (W R, W G,} W B) once sent to the system controller 30 of the video signal processing unit 12, to be output to the DSP52 of the video signal processing circuit 34 from which become.

Further, in the above-described embodiment, the color filter (CF ₁₈ , CF ₆₀ ) which is composed of the three primary color filter elements of red, green and blue is used, but the color filter including the complementary color filter element is used. It should be understood that the present invention is applicable even when used.

[0084]

As is apparent from the above description, in the electronic endoscope according to the present invention, it is necessary to create troublesome white balance correction data every time the electronic endoscope is used after heat sterilization. Since it is not necessary to perform the medical examination, it is possible to efficiently perform the medical examination by the electronic endoscope system.

[Brief description of drawings]

FIG. 1 is an overall schematic block diagram of an electronic endoscope system using an electronic endoscope scope according to the present invention.

FIG. 2 is a schematic block diagram of the light source device shown in FIG.

FIG. 3 is a detailed block diagram of a scope-side processing circuit shown in FIG.

FIG. 4 is a detailed block diagram of the video signal processing circuit shown in FIG.

5 is a flowchart of a white balance correction data creation processing routine executed by the scope-side controller shown in FIG.

FIG. 6 is a part of a flowchart of a white balance correction data correction processing routine executed by the scope-side controller shown in FIG.

7 is the remaining part of the white balance correction data correction processing routine executed by the scope-side controller shown in FIG.

[Explanation of symbols]

10 Electronic Endoscope 12 Video Signal Processing Unit 14 TV Monitor Device 16 Switch 18 CCD Imaging Device for Imaging (Solid Imaging Device for Imaging) 24 Scope-side Processing Circuit 26 Light Guide Cable 30 System Controller 32 Timing Controller 34 Video Signal Processing Circuit 36 Light Source Device (White Light Irradiating Means) 50 Scope Side Controller 52 DSP (White Balance Correction Data Creating Means and Correction Data Creating Means) 54 CCD Driver 56 A / D Converter 58 EEPROM (Memory Means) 60 CCD Image Sensor for Monitoring ( Color filter Discoloration monitoring solid-state image sensor) 62 White LED 64 LED power supply circuit 66 CCD driver 68 A / D converter 70 Video signal pre-processing circuit 72 Memory 74 Video signal post-processing circuit CF ₁₈ / CF ₆₀ Color filter

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2H040 BA00 BA23 DA21 GA02 GA06                 4C061 CC06 DD03 FF12 LL02 MM05                       NN01 SS09 TT04                 5C065 AA04 BB02 CC01 DD02 EE03                       FF05 GG15 GG27                 5C066 AA01 CA17 EA04 EA14 GA04                       KA12 KE07 KM01 KM05 KM10

Claims (4)

[Claims] 1. An electronic endoscope having an imaging solid-state imaging device incorporating a color filter for obtaining an endoscopic image as a color image, wherein the color filter of the imaging solid-state imaging device is free from deterioration of color fading. A solid-state image sensor for color filter fading monitoring incorporating a color filter having the same characteristics as the color filter for monitoring the degree, and white light irradiation for irradiating the color filter of the solid-state image sensor for color filter fading monitoring with white light. Means, white balance correction data creating means for creating white balance correction data for setting a gain when amplifying an image signal of each color of a color image signal obtained from the solid-state imaging device for photographing, and the white balance correction Memory means for storing data, and a color obtained from the solid state image sensor for color filter fading monitoring when the white light source is illuminated. Electronic endoscope scope which is characterized by comprising; and a correction data generating means for generating a correction data for correcting the white balance correction data based on a broadcast signal. 2. The electronic endoscope according to claim 1, further comprising: correcting white balance correction data based on the correction data created by the correction data creating means to obtain from the solid-state imaging device for photographing. An electronic endoscope scope, characterized in that a white balance processing means for performing white balance correction processing on the obtained color image signal is provided. 3. The electronic endoscope scope according to claim 1, wherein each time the white balance correction data creating means is operated to create the white balance correction data, the correction data creating means is also operated. An electronic endoscope scope characterized in that corrected data is newly created. 4. The electronic endoscope according to any one of claims 1 to 3, wherein the correction data creating means is operated every time the electronic endoscope is used to perform the correction. An electronic endoscopic scope characterized in that data is updated.