JPH08211306A - Photographing device - Google Patents

Abstract

PURPOSE: To provide a photographing device capable of always performing proper exposure correction regardless of the size and display position of an image. CONSTITUTION: Chrominance signals of R, G, B are inputted to an image display device 7 to be displayed on a CRT display part 17 in color sequence. A luminance signal is generated from the chrominance signals of R, G, B to a mean luminance calculation part 21 and an image area calculation part 22, and after mean luminance and an image area are calculated, the mean luminance of the image is obtained by an exposure control part 23, and an amplification factor of a VGA 16 is controlled, and mean brightness of an image part in a video signal displayed on the CRT display part 17 is made independent of the image area, etc., and a color image is obtained by multiple exposing at a prescribed exposure time by a camera 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographic device for making a hard copy of an image corresponding to a video signal.

[0002]

2. Description of the Related Art In recent years, endoscopes have been widely used in medical fields and industrial fields. Further, an electronic endoscope having a built-in solid-state image pickup device such as a CCD at the tip of the insertion portion is also widely used. In the case of an electronic endoscope, a captured image pickup signal is converted into a video signal by a signal processing device such as a video processor and input to an image display device such as a CRT, and an endoscopic image displayed on an image display surface. Will be observed.

Particularly in the medical field, there are many needs for a hard copy of the endoscopic image displayed on the image display device, and for this reason, a photograph for taking a picture of the endoscopic image displayed on the image display device. There is a photographing device.

However, depending on the structure of the subject, the way the illumination light hits, the distance from the subject to the image sensor, etc., the image obtained by the electronic endoscope may have a very high or low average luminance of the video signal. As described above, even if a bright image or a dark image is taken, it is difficult to perform correct image diagnosis unless the brightness is constant on the film.

Therefore, the conventional photographic device, as a part of which is shown in FIG. 10, is a method for keeping the brightness of the image on the photograph constant, and the average brightness of the input video signal is calculated by the average brightness calculating circuit 91. Then, the amplification factor of the amplifier 92 for amplifying the video signal is changed according to the level of the average luminance value, the image on the screen of the CRT 93 is always kept constant, and this image is photographed by a camera (not shown). For example, it is realized by increasing the amplification factor when the average luminance is low and decreasing the amplification factor when the average luminance is high.
This conventional example is effective when used in the same electronic endoscope.

[0006]

However, the endoscopic image obtained by the electronic endoscope is displayed on the CRT screen as shown in FIGS. 11A, 11B, and 11C depending on the type and use of the electronic endoscope. The size and display position of the image displayed on the screen 94 are different.

Therefore, when the above-mentioned conventional example is used in the case of electronic endoscopes of different types, the same subject has the same waveform level of the video signal as shown below the CRT screen 94 (in the time axis direction). Only enlarged or reduced,
The peak level and the like are equal as shown by the chain double-dashed line), but the value of the average luminance AY is different.

For example, in the endoscopic image of FIG. 11 (B), the average luminance AY is lower than that of FIG. 11 (A), so the amplification factor is high, and overexposed highlights occur on the photograph. It is easy to become. In addition, in the endoscopic image of FIG. 11C, the average luminance AY is higher than that of FIG. 11A, and therefore the amplification factor is low. There is a problem that improper exposure compensation such as the occurrence of an error occurs.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a photographic device capable of always performing appropriate exposure correction regardless of the size and display position of an image.

[0010]

In a photographic device for displaying a video signal including an image on an image display device and taking a picture with the image shooting device, an average brightness calculating device for calculating an average brightness of the video signal. An area calculating means for calculating an area of an image from the video signal, and an image pickup means for controlling an exposure amount when a picture is taken by the image taking means by the values of the average luminance and the area. Even if the size or display position of the image on the image display device changes depending on the type of endoscope, the average brightness of the displayed image portion is made constant by the values of the average brightness and the area to control the exposure amount. By controlling the exposure time on the image photographing means side, a photographed image of proper exposure is obtained.

[0011]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 shows the configuration of an endoscope apparatus including the first embodiment of the present invention, FIG. 2 shows the configuration of a photography apparatus of the first embodiment, and FIG. 3 shows the characteristics of VGA.

In the first embodiment, the brightness level of the video signal displayed on the image display means is controlled to control the exposure amount when the image is taken through the image taking means, thereby controlling the area size of the image. Even if the display position is different, a color hard copy suitable for diagnosis can be obtained.

As shown in FIG. 1, an endoscope apparatus 1 including the first embodiment includes an electronic endoscope 2 having an image pickup element built therein, and a light source device 3 for supplying illumination light to the electronic endoscope 2. , A video processor 4 for processing signals to the image pickup device of the electronic endoscope 2, a color monitor 5 for displaying a video signal output from the video processor 4, and the video processor 4.
And a picture taking device 6 of the first embodiment having a function as a hard copy device for taking a picture of a color image by a release operation.

The photographic device 6 multiple-exposes an image display device 7 for displaying an input video signal as, for example, a frame sequential color component image and a color component image displayed on the display screen of the image display device 7. And a camera 8 as an image photographing device for photographing a color image.

The electronic endoscope 2 has a light guide (not shown). Illumination light is supplied from a light source device to the proximal end surface of the light guide, and the illumination light is transmitted to the end surface on the distal end side of the insertion portion. To illuminate a subject such as a diseased part. An optical image is formed on the illuminated subject by an objective lens attached to an observation window at the tip end, and an optical image is formed on the image pickup element arranged at the image forming position, and photoelectric conversion is performed by the image pickup element.

An image pickup device drive signal from the video processor 4 is applied to the image pickup device, and an image pickup signal corresponding to the picked-up endoscopic image is input to a signal processing circuit in the video processor and converted into a video signal. It This video signal includes an endoscopic image taken by the electronic endoscope 2,
Generally, in the case of different types of electronic endoscopes, the size of the endoscopic image portion included in the video signal is different.

When the control unit 10 determines that the R, G, B color signals, which are video signals output from the video processor 4, are pressed by the operator (by the operator) as shown in FIG. After being converted into color signal digital data by the A / D converters 11a, 11b, and 11c, video data for one frame is written in the frame memory 12.

Writing to the frame memory 12 is performed by the control unit 10 based on the ODD / EVEN sync signal generated by the sync signal processing unit 13 to which the sync signal SYNC from the video processor 4 is input. The sync signal processing unit 13 synchronously separates from the input composite SYNC signal to obtain VSYNC, HSYNC, BLANKING.
In addition to the signal, ODD / EVEN, a clamp pulse, and a 4fsc clock signal (four times the subcarrier frequency fsc) are generated.

The frame memory 12 is composed of, for example, an image memory consisting of three plane memories, an address generator, and a memory control circuit. Digital data of R, G, B color signals are simultaneously stored in the respective plane memories. Written.

The digital data written in the frame memory 12 passes through an image data changeover switch 14 as an image data changeover means controlled by the control unit 10 and then R,
The signals are output in the order of G and B, input to the D / A converter 15, and converted into analog color signals. This color signal is further amplified by the VGA 16 whose gain (amplification factor) changes according to the voltage applied to the control end, and then output to the CRT display unit 17 using a CRT as a monochrome image display element, and a color component image is displayed. Displayed sequentially.

The R, G, B color signals are input to the luminance signal generator 18, and the R, G, B color signals are 0.3R +.
A luminance signal is generated by performing mixing (or addition) processing so that the luminance signal becomes 0.6G + 0.1B. This brightness signal is converted into a digital brightness signal through the A / D converter 19, and then the average brightness calculation unit 21 and the image area calculation unit 22.
Entered in and.

In addition to the above signals, the synchronization signal processing unit 13
In the effective image area during the frame period, for example, 15 points at equal intervals in the horizontal direction and 15 points at equal intervals in the vertical direction, a total of 225 points, are also generated as the image image sampling clocks of 4 fsc clock width, and the average brightness calculation unit 21. To the image area calculation unit 22.

Then, the average brightness calculating section 21 cumulatively adds the digital data of the brightness signal sent from the brightness signal A / D converter 19 for each frame interval for each image image sampling clock, and cumulatively adds for one frame interval. The data is supplied to the exposure control unit 23 as the average brightness value of the image.

The image area calculation unit 22 compares the digital data of the luminance signal sent from the luminance signal A / D converter with the reference value E for each frame image image sampling clock, and when it is larger than the reference value E. The counter is incremented, and the data counted in one frame section is supplied to the exposure control unit 23 as an image area value. The reference value E in this case is set to about 7.5 IRE, for example.

The exposure control unit 23 divides the average brightness value from the average brightness calculation unit 21 by the image area value from the image area calculation unit 22, and determines the quotient value as the brightness of the input image. The brightness data of the image is converted into the control data of the VGA 16 by the conversion table memory 23a in the exposure controller 23. The contents of the conversion table memory are as shown in the graph in FIG.
The coefficient data in which the amplitude value after output is always constant is stored.

Therefore, when a video signal is displayed on the CRT screen of the CRT display unit 17, the average brightness in the endoscopic image portion actually displayed on the display screen is different when the endoscopic image size is different. Will always be constant.

The conversion table memory 23a may be a ROM or a RAM. Also, to obtain the image brightness data, the average luminance value was divided by the image area value.However, because the division process requires additional hardware and costs increase, the image area value can be divided into multiple classes. It is also possible to generate the brightness of the image by classifying into, and multiplying the average luminance value by the coefficient assigned to each class.

In this embodiment, the controller 10 and the exposure controller 2
Although 3 and 3 are provided, they can be combined into one by a microcomputer. The exposure controller 23 outputs the VGA control data to the D / A converter 24, converts it into an analog voltage, and supplies it to the gain control terminal of the VGA 16 to determine the amplification factor of the VGA 16. VGA16 is
The larger the VGA control data, the higher the amplification factor.

The color signal amplified by the VGA 16 is displayed on the CRT display section 17. The image displayed on the CRT display unit 17 is formed by a taking lens 25 on a color film (hereinafter, simply referred to as a film) 26 arranged on an image forming surface thereof. A rotary color filter 27 is arranged in the optical path between the taking lens 25 and the film 26, and the rotation of the rotary color filter 27 is controlled by a rotary color filter driving unit 28 including a motor.

The rotary color filter 27 is provided with red, green and blue color filters corresponding to the R, G and B color signals, for example, in the circumferential direction of the disk to display an image of the R color signal. If so, the rotation color filter drive unit 28 controls the rotation (color filter position in the optical path) so that the red color filter is arranged in the optical path.

The control signal or command from the control unit 10 is supplied to the rotary color filter drive unit 28 so as to control in this manner. Next, the operation of this embodiment will be described.

When the release switch 9 is turned on, the control unit 10 responds to this release operation by synchronizing signal processing unit 1
Based on the ODD / EVEN signal from No. 3, the frame memory 12 is controlled to store image data for one frame period. For example, one frame of image data may be constantly stored in the frame memory 12 by overwriting, and writing of the next image data may be prohibited when the release switch 9 is turned on. If the release switch 9 is turned on without performing,
The image data may be written immediately after that.

When the control section 10 judges that the storage of the image data for one frame period has been completed, the red color filter is provided in the optical paths of the CRT display section 17 and the film 26 to the rotary color filter drive section 28. Output command to be set.

After the setting of the red color filter is completed, the control unit 10 sets the frame memory 12 to the read mode, sets the image data changeover switch 14 so that the image data of R is selected (state of FIG. 2), and D / It is output to the VGA 16 side through the A converter 15 and is amplified by the VGA 16.
The color signal of is displayed on the CRT display unit 17.

On the other hand, the R, G, B color signals are input to the luminance signal generating section 18 to generate luminance signals,
This brightness signal is used as an average brightness calculation unit 21 and an image area calculation unit 2.
The average brightness and the area of the actual endoscopic image included in the video signal are calculated by inputting the data to the area 2. Then, the exposure controller 23 calculates the average brightness of the endoscopic image by dividing the average brightness by the area of the endoscopic image, and the VGA control data corresponding to the average brightness. From the conversion table memory 23a,
The VGA control data controls the amplification factor (gain) of the VGA.

By this control, the CR of the CRT display section 17
The average brightness of the endoscopic image portion displayed on the T screen is always constant even when the size of the endoscopic image is different.

By photographing with the camera 8 with a constant exposure time, the average brightness (or average luminance) in the image portion is always constant even when the size of the endoscopic image is different. You can get a hard copy in color. In this case, the fixed exposure time is set to a predetermined time that provides an exposure amount suitable for diagnosis, and shooting is performed as follows.

The image displayed on the screen of the CRT display unit 17 is passed through the rotary color filter 27 by the lens 25 and then focused on the film 26 to start the exposure of the R image. The control unit 10 causes the film 26 to be exposed with the R image for a predetermined time so as to obtain an appropriate exposure amount. When the exposure of the R image is completed, the control unit 10 outputs a command to the rotary color filter drive unit 28 to set the G color filter, and the rotary color filter drive unit 28 rotates the rotary color filter 27 by 120 degrees, for example. Then, after setting the G filter in the optical path, the image data changeover switch 14 is set so that the G image data is selected,
The G image is exposed on the film 26 for a predetermined time.

After the exposure of the G image is completed, the B image is also R
The image and G image are processed in the same manner as the exposure procedure, and on the film 26, the R, G, and B images are subjected to multiple exposure to be colorized and photographed.

According to the first embodiment, the means for calculating the average luminance of the video signal, the means for calculating the area of the endoscopic image included in the video signal, and the mean of the endoscopic image from these means. Is calculated, and the average brightness of the endoscopic image on the CRT display unit 17 is controlled based on the average brightness of the endoscopic image so that the camera 8 takes a picture. Even when the area of the endoscopic image displayed on the CRT display unit 17 is different, such as when using different electronic endoscopes, the average brightness in the endoscopic image portion on the CRT display unit 17 is It is always constant regardless of the area size of the mirror image, so even when the image area of the film obtained by filming is different, the average brightness in the image area is constant and a level suitable for diagnosis. When That.

FIG. 4 shows a main part in a modification of the first embodiment. In the above embodiment, since the image data is captured, the average brightness is calculated, and the image area is calculated simultaneously, the brightness signal A
Although the A / D converter 19 is provided, the A / D converter 19 for the luminance signal is not provided independently and other A / D converters 19 are provided as shown in FIG.
If the input switch 31 is provided in any of the A / D converters 11a to 11c so that the input can be input to any of the A / D converters 11a to 11c (B signal in the present embodiment), the brightness signal A / The D converter 19 can be omitted.

However, at that time, it is also possible to first switch the input switch 31 to the luminance signal, calculate the average luminance and the image area, and then switch to the color signal side to fetch the image data. In the case of this configuration, since the luminance signal is displayed on the CRT display unit 17 except during the exposure, it is convenient for checking the input image.

In FIG. 4, since the image digital data of the average brightness calculating section 21 and the image area calculating section 22 passes through the image data changeover switch 14, a 4-input data changeover switch 32 is provided and the A / D converter is provided. The image data currently input can be supplied by switching the output to 11a to 11c, and the image data read from the frame memory 12 can be supplied by switching the data changeover switch 32 to the frame memory 12 side. it can. According to this modification, the cost can be reduced as compared with the case of the first embodiment. Others have the same operation and effect as the first embodiment.

Next, a second embodiment of the present invention will be described. In this embodiment, it is possible to take a photograph in a standard size and an enlarged size. An image obtained by a normal electronic endoscope device is an endoscopic image obtained by an image pickup device (for example, CCD) at the tip of a scope, as well as an examinee's name, sex, date of birth, examination date, and the like. The data will be displayed.

Therefore, when a photograph of the object displayed in this state is photographed on the film, an endoscopic image and the object data beside the endoscopic image are obtained as shown in FIG. 6 (A). Become.

In this state, the photographed endoscopic image can be identified by the subject data, but for diagnosis, the endoscopic image portion obtained by photographing is too small to make a diagnosis. In some cases. Therefore, by displaying only the endoscopic image on the CRT display unit 17 and exposing the film, it is possible to take a photograph in which the endoscopic image on the film can be enlarged as shown in FIG. 6B. What is done is the photo-taking device 36 of the second embodiment, the construction of the main part of which is shown in FIG.

The picture taking device 36 is an image display device 37.
2 and a camera 38, and the image display device 37 is shown in FIG.
In the image display device 7 of, a D / A converter 15 and
A character mask unit 40 for masking a character information portion is provided between the VGA 16 and the VGA 16.

Further, in the image display device 7 of FIG. 2, the following constituent elements are added.

A camera discriminating means 41 for discriminating which kind of camera is mounted on the image display device 37 as an image photographing device to be used, and a photographing size selecting means 42 for selecting a photographing size by an operator. , A camera frame number counting means 43 for checking the number of frames to be photographed, a control section 44 connected to these means and performing corresponding control based on information from each means, and an output signal of the control section 44 being D / CRT scanning line generation for changing the scanning speed of the scanning line of the CRT display unit 17 based on the output signal of the D / A converter 45 for A conversion and the control unit 44 when the enlargement size is selected to perform enlarged display And a portion 46.

The camera discriminating means 41 discriminates which kind of camera 38 is being used and discriminates the discriminating information.
Output to. The determination of the camera 38 is performed by, for example, each camera 38
A resistor R having a different resistance value is provided according to the type, and the camera discriminating means 41 discriminates the camera 38 used by examining the value of the resistor R. Besides resistance, barcode,
The camera 38 may be discriminated by a discrimination pin or the like provided on the connector. Other configurations of the camera 38 are the same as those of the camera 8 of the first embodiment.

The control unit 44 outputs correction information for correcting the VGA control data to the exposure control unit 23 according to the camera 38 used. By supplying the correction information, the VGA control data output from the exposure control unit 23 to the VGA 16 becomes appropriate considering the type of the camera 38 actually used, and the operator does not have to worry about the camera 38. I am able to take a picture and get the same exposure as when I took a picture with another type of camera.

Further, the photographing size selection means 42 allows the operator to select whether the photographing size is the standard size as shown in FIG. 6A or the enlarged size as shown in FIG. 6B. The selection information is supplied to the control unit 44. Further, the control unit 44 checks the number of frames to be photographed by the camera frame number counting unit 43, and ignores the information of the photographing size selection unit 42 and sets the standard size in the case of the first frame.

This is because it does not occur that the data of the presenter is not shown on the film to be photographed. Except for the first frame, based on the information of the photographing size selection means 42, the image information other than the endoscopic image area is masked to the character mask section 40 at the time of enlargement size.

This is because when the enlargement processing results in that only a part of the subject data remains on the film, the characters of the subject data are erased so that it is not recognized as wrong information. In the standard size, the character mask unit 40 sends the video signal input from the input end as it is to the VGA 16 side. When the enlargement size is selected, the control unit 44 makes the scanning line interval faster than the standard size with respect to the CRT scanning line generation unit 46 that generates the scanning lines of the CRT display unit 17, thereby increasing the scanning speed of the scanning lines. By doing so, it is instructed to enlarge the display size and move the display position to the left of the standard size.

As a method for enlarging the display size, there is an electronic zoom for enlarging the image data while performing interpolation processing, and this may be adopted. In the case of this electronic zoom, blurring may occur in the magnified image depending on the calculation error of the interpolation processing, so in this embodiment, the image magnifying means by overscan of the CRT is adopted.

This means is advantageous because it can be enlarged easily without lowering the resolution. However, if overscan is performed, the scan line density will drop, and even if the same video signal is input, overscan is more C than standard scan.
Since the brightness on the RT screen decreases, the control unit 44 sends an instruction signal to the exposure control unit 23 so as to perform correction to increase the VGA control data when the enlargement size is selected.

As a result, the operator simply selects the photographing size, and the photographing sensitivity is automatically corrected to an appropriate value to obtain a photograph with an appropriate exposure amount suitable for diagnosis. Although this embodiment has two control units 10 and 44, they may be integrated into one control unit.

Next, a third embodiment of the present invention will be described. In this embodiment, when the operator forgets to set the film in the camera and tries to take a picture, the photographic device has a function of warning the operator that no film is set. is there. A specific description will be given with reference to FIG. 7.

The photo-taking device 56 of the third embodiment shown in FIG.
Is composed of an image display device 57 and a camera 58 as a photographing device. For example, the following film detecting mechanism 59 is added to the photographing device 6 of the first embodiment shown in FIG.

For example, a camera power source 60 built in the image display device 57 is supplied to an electronic circuit 63 in the camera 58 via a relay switch 61 and a resistor 62. This electronic circuit 63 is a film winding motor, a mirror UP / D
The OWN motor and a control circuit for controlling these are included, and serve as a load for the camera power supply 60. The electronic circuit 63 includes a back cover opening / closing detection circuit 6 for detecting the opening / closing of the back cover.
A detection signal for closing the back cover is input from the No. 4. The resistor 62 has a low resistance of about 1 to 2 ohms.

Further, the resistor 6 is provided in the image display device 57.
A detecting means for detecting the voltage drop at 2 is provided, and the film is detected by the amount of the voltage drop. That is, the voltage across the resistor 62 is amplified by the differential amplifier 65 and then converted into a digital amount by the A / D converter 66. The digital data converted at equal intervals by the A / D converter 66 is input to the control unit 10, accumulated in, for example, a memory in the control unit 10 to integrate the data, and the control unit 10 uses the integrated value to perform integration. It is determined whether there is a film in the camera 58. Camera 5
The integrated value is different between the state where the film is inside 8 and the state where there is no film as follows.

In the camera 58, when the back cover opening / closing detection circuit 64 detects the back cover opening to the back cover closing, the control unit in the electronic circuit 63 causes the film to be wound up by three frames. At this time, when the film winding motor winds the film, it requires more current than the normal operation.
As shown in (A), when there is a film, the amount of voltage drop at the resistor 62 increases while winding the film by three frames.

On the other hand, as shown in FIG. 8 (B), when the film is not present, the time during which the amount of voltage drop increases is considerably shorter than when it is present. That is, the integral value is greatly different between the state where the film is inside the camera 58 and the state where the film is not inside. Due to the difference in the integrated value, two states can be discriminated by using the integrated value between them as a reference.

When the operator presses the release switch 9 with no film in the camera 58, the control section 10 controls the buzzer (or buzzer sound generating section) 67 to generate a buzzer sound, and operates it. Warn the operator that there is no film in camera 58. In this way, it is possible to prevent shooting without noticing that there is no film in the camera 58. Others have the same operations and effects as the first embodiment.

By the way, generally, the setup level included in the video signal output from the camera control unit (hereinafter referred to as CCU) or the video processor may vary slightly from product to product. The color tone changes on the film taken, and the color of the affected area and blood becomes a problem that cannot be ignored in endoscopic photography which is diagnostically demanded. The configuration and the like of the fourth embodiment shown in FIG. 9 will be described in detail for the purpose of solving the problem that the conventional color tone changes depending on the camera unit.

The R, G and B signal input terminals of the image display device 71 are respectively pedestal clamp circuits 72a and 72a.
b and 72c are connected, and the pedestal clamp circuit 72 is connected.
The output signals of a, 72b, and 72c are converted into digital amounts by A / D converters 11a, 11b, and 11c, respectively, and then D / A via the image data changeover switch 14.
It is input to the converter 15 side, converted into an analog amount, and then output to the CRT display unit 17 via the VGA 16.

Pedestal clamp circuit 72i (i =
a, b, c) are two buffer amplifiers 73i, 74i
And a capacitor 75i for blocking direct current between them, and a switch 76i for pedestal clamp (and also for superimposing variation elimination signal). This switch 76
i is, for example, 5 from the horizontal synchronization signal from the synchronization signal processing unit 13.
It is turned on by the clamp pulse delayed by μS, and the input terminal level of the buffer amplifier 74i is clamped to the pedestal level.

Further, the control section 10 can supply the reference voltage for setup adjustment to the switch 76i via the D / A converter 77i. Therefore, when the reference potential is applied with the switch 76i turned on, the potential level at the input end of the buffer amplifier 74i becomes a state in which the reference potential is added to the pedestal clamp level, and the image data changeover switch 14
The signal selected by is sent to the CRT display unit 1 via the VGA 16.
It is displayed on 7. In this case, the VGA 16 is held at a constant voltage, that is, a constant amplification factor.

The brightness of the image displayed on the CRT display section 17 is measured by the photometric element 79, photoelectrically converted, and then converted into digital data by the A / D converter 80 and input to the control section 10. It

The control unit 10 has a setup switch 81.
Is connected, and the operator operates the setup switch 81
When it is detected that the button has been pressed, the control unit 10 cancels the setup variation of the R, G, and B color signals by performing the operation control described later. Information for canceling the setup variation of the R, G, B color signals is stored in the storage unit 83.

Further, an automatic / manual changeover switch 82 is connected to the control unit 10 so that the setup variation can be canceled in the automatic changeover state, or the setup variation can be canceled in the manual changeover state. You can also A setup adjusting means 84 is provided so that adjustment for canceling variations in setup can be performed in the state of manual switching.

That is, the pedestal clamp circuits 72a, 72b, 7 are operated by operating the setup adjusting means 84.
The clamp potential applied to 2c can be variably set, and the clamp potential set to the pedestal clamp circuits 72a, 72b, and 72c can be applied through the control unit 10 by turning on the setup switch 81, thereby canceling variations in setup. Adjustments can be made.

Next, the operation of this embodiment will be described. The operator puts the light into the observation window of the electronic endoscope,
This image display device 7 from the video processor or CCU
The video signal input to 1 does not include the setup signal. Next, the operator sets the automatic / manual changeover switch 82 to the automatic changeover state, and by pressing the setup switch 81, the control unit 10 performs the following movements to cancel the setup variation of the R, G, B color signals. To do.

The control unit 10 sets data corresponding to the reference potential in the D / A converter 77a and supplies the output of the D / A converter 77a to the pedestal clamp circuit 72a for the R signal as a clamp potential. Control unit 10
After the R signal including only the setup signal converted into digital data by the A / D converter 11a is selected by the image data changeover switch 14, the R signal is converted again into analog data by the D / A converter 15, and VGA
It is displayed on the screen of the CRT display unit 17 via 16.

The control unit 10 converts the brightness of the screen on the CRT display unit 17 from light to voltage by the photometric element 79, digitizes the voltage by the A / D converter 80, and measures the setup level of the R signal. To do.

Next, the control unit 10 controls the D / A converter 77.
Data corresponding to the same reference potential as the R signal is set in b, and the output of the D / A converter 77b is supplied to the G signal pedestal clamp circuit 72b as a clamp potential.

The control unit 10 selects the G signal, which is only the setup signal converted into digital data by the A / D converter 11b, by the image data changeover switch 14 and then re-analogs it by the D / A converter 15. The data is converted into data and displayed on the CRT display unit 17, and the control unit 1
In 0, the brightness of the screen on the CRT display unit 17 is converted from light to voltage by the photometric element 79, the voltage is digitized by the A / D converter 80, and the setup level of the G signal is measured.

At this time, it is compared with the setup level of the R signal to see if it is within a certain allowable value. If it is not within the allowable value, the setup potential of the G signal is varied so as to be within the allowable value. Similarly, the B signal is processed in the same manner as the G signal to cancel the setup variations of the R, G, and B color signals.

Further, by storing the clamp potentials of the G signal and the B signal capable of canceling the setup variation in the storage section 83, the clamp potential stored in the storage section 83 can be read out after the power is turned on. , D / A converters 77a, 77b, 77c
The operator can always obtain a stable color tone without canceling the setup variation.

In addition, another video processor or CCU
Even when connected to, the operator can cancel the setup variation and obtain the same color tone, which is useful for diagnosis. In addition, when the automatic / manual changeover switch 82 is set to the manual state and the setup switch 81 is pressed, the clamp potential designated by the setup adjusting means 84 is output to the D / A converters 77a, 77b, 77c. Can also set the clamp potential freely.

The fourth embodiment may be added to the first embodiment. Note that, for example, in the first embodiment, the gain of the amplifier whose gain changes depending on the voltage is a value obtained by dividing the average brightness of the image by the image area, that is, the average brightness per unit area Although the proper exposure is always obtained even if the area size and the display position change, the present invention is not limited to this, and the exposure time may be controlled.

For example, in the first embodiment of FIG. 2, the value obtained by dividing the average brightness of the image by the image area by the exposure control unit 23, that is, the average brightness per unit area is passed through the D / A converter 24 to the rotary color filter. By applying to the drive unit 28 (or applied to the rotary color filter drive unit 28 via the D / A converter 24 and the control unit 10) and controlling the exposure time for exposing the film 26 through the rotary filter 27, the image It is also possible to always obtain an appropriate exposure even if the area size and display position of the are changed (in this case, an amplifier capable of changing the amplification factor like the VGA 16 is not necessary, of course, a constant amplification factor You may use an amplifier).

That is, the exposure time may be controlled so that the product of the average brightness and the exposure time becomes approximately constant, depending on the detected average brightness. Therefore, the one that controls at least one of the display brightness and the exposure time by the average luminance belongs to the present invention, and includes those that control both.

Note that, for example, the first embodiment of FIG. 2 does not mention the case where the video signal input to the image display device 7 includes the character information. In the case of a video signal including character information, the CRT display unit is configured so that the average luminance in these areas is constant with respect to the character display area in which the character information is displayed and the image display area in which the image is displayed. The exposure amount is controlled by controlling the average brightness at 17.

Even in the case of a video signal including character information, the average brightness of the CRT display unit 17 is controlled so that the average brightness is constant in only the image display area in which the image is displayed. The exposure amount may be controlled as described above.

To realize this, for example, in FIG. 2, the digital signal that has passed through the A / D converters 11a, 11b, 11c is input to the image area calculation unit 22, and the image area calculation unit 22 performs R, G , B color signals are both at the same level, and a value obtained by accumulating the values determined to be at the same level is calculated through the A / D converter 19 (value including characters and images). Subtract it.

To determine whether the levels are the same,
Since the R, G, and B color signals are generally set to the same level for the character information, an OR circuit for obtaining an exclusive OR of three inputs is passed through a window comparator for detecting this level, respectively. Through this, the value corresponding to the character information area can be obtained by cumulatively adding the output of this OR circuit with the counter. R for character information,
When the ratio of the G and B color signal levels is different, the detection level may be changed accordingly.

It is not limited to the automatic setting, but the operator inputs information on the display area of the character information, or the operator operates the mask means to display the display area of the character information on the average of the image. Even in the case of a video signal containing character information, for example, by masking only when obtaining the luminance, only in the image display area where the image is displayed, the CRT display unit is configured so that the average luminance in this area is constant. The exposure amount may be controlled by controlling the average brightness at 17.

In the above description, the image display device is described as being composed of a CRT display section using a CRT, but the present invention is not limited to this, and image display means using a liquid crystal display device or the like. But good.

Further, in the above, the CRT for displaying the video signal
Display characteristics or input / output characteristics of display elements such as (specifically, the displayed optical brightness (or video brightness) of the (electrical) brightness level of the input video signal) Characteristic) and
Basically, the same can be applied when the input / output characteristics are not linear.

For example, when the video signal input to the photographic device 6 of FIG. 2 has already been gamma-corrected in consideration of the characteristics of the CRT of the CRT display section 17, the method can be applied as it is.

For example, when it is assumed that the image is displayed on a CRT and the gamma-corrected video signal for the CRT is displayed using a display element having a different display characteristic for shooting, the effect of the gamma correction is If correction is made to eliminate it, the same can be applied.

The photographic device in the above description displays each video signal of the color component on the monochrome display element (for example, CRT) of the image display device in color order, and the image capturing means side displays each of the displayed color components. Although a color film is subjected to multiple exposure through a color filter corresponding to a video signal to obtain a color hard copy, the present invention is not limited to this.

For example, in FIG. 2, the color signals of R, G, and B are simultaneously output to the CRT display section 17 side (in this case, the CRT display section 17 is a color display section for displaying in color by three color signals). It may be necessary), and on the camera side, the color film 26 may be exposed without interposing the rotary color filter 27 in the optical path.

In addition, the color display on the color display means using the luminance signal and the two color difference signals is exposed on the color film 26 without interposing the rotary color filter 27 in the optical path on the camera side as described above. You can do it.

Although the electronic endoscope has been described in the first embodiment, a TV camera having a built-in image pickup means is attached to the eyepiece of the optical endoscope in addition to the electronic endoscope. It can also be applied to the case of an endoscope.

In the above description, even when the image area is different, the exposure amount is controlled by setting the exposure time to be constant so that the average brightness of the image portion is constant, or used for display. Although the level of the video signal to be controlled is not variably controlled, the exposure amount is controlled by variably controlling the exposure time so that the average exposure amount of the image portion is constant on the image capturing side. In addition to what is controlled, the following control may be performed.

For example, the dynamic range in which an image can be displayed on an image such as a CRT or an image display device is narrower than the dynamic range of a photographed image of a color film. For this reason,
For example, in FIG. 2, a compression unit (for example, a logarithmic compression amplifier) for compressing the output characteristic with respect to the input of the video signal is provided on the front side of the CRT display unit 17, and, for example, the average luminance of the image is the center of the dynamic range of the image display element. The levels may be compressed and displayed. In this way, a color image suitable for diagnosis with less black spots or blown-out highlights can be obtained.

In this case, if the color sequential display and photographing are performed, one compression means can be used in common, so that the color tone is changed due to the variation in the characteristics of the plurality of compression means (as in the case of the color display which is not the color sequential). Therefore, it is possible to effectively prevent the occurrence of the change.

In this case, at least the exposure amount is controlled based on the average luminance of the video signal and the image area. It should be noted that the embodiments and the like configured by partially combining the above-described embodiments and the like also belong to the present invention.

[Additional Notes] 1. In a photographic device that displays a video signal on an image display device and takes a picture with a photographing means, when an input video signal is amplified by an amplifier and displayed on the image display device, the average brightness of the input video signal is calculated. An average brightness calculating means for calculating, an area calculating means for calculating an image area from the video signal, and a control means for controlling an amplification factor of the amplifier from the values of the average brightness and the image area are provided. Photography equipment.

2. In Appendix 1, the control value of the amplifier is generated from a value obtained by dividing the average luminance value by the area value. 3. In Appendix 1, the control value of the amplifier is a correction value of the brightness value, and is generated from a value corrected by the correction value.

4. In Additions 1, 2, and 3, the video signals are displayed on the image display device in order of different colors, and the screen of the image display device is sequentially photographed on a color film through the color filters of different colors. Photography equipment. 5. In claim 1, the control of the exposure amount controls the luminance of the video signal displayed on the image display device based on the average luminance and the value of the area. 6. In the first aspect, the control of the exposure amount controls the exposure time by the image capturing means based on the values of the average luminance and the area.

[0104]

As described above, according to the present invention, in a photographic device for displaying a video signal including an image on an image display device and taking a picture with an image shooting means, the average luminance of the video signal is calculated. An average brightness calculation means, an area calculation means for calculating an area of an image from the video signal, and a value of the average brightness and the area so as to control an exposure amount when a picture is taken by the image shooting means. Therefore, even if the size or display position of the image on the image display device changes depending on the type of the endoscope having the image pickup means, the average luminance of the image portion displayed is made constant by the values of the average luminance and the area. The exposure amount is controlled by controlling the exposure amount so that the average luminance in the image portion is constant on the image capturing means side, so that a photographed image with proper exposure can always be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an endoscope apparatus including an embodiment of the present invention.

FIG. 2 is a configuration diagram showing a configuration of a photographic device according to a first embodiment.

FIG. 3 is a characteristic diagram showing the characteristics of VGA.

FIG. 4 is a block diagram showing a main part of the first embodiment.

FIG. 5 is a configuration diagram showing a configuration of a main part of a photography device according to a second embodiment of the present invention.

FIG. 6 is a diagram showing an image of a film obtained by photographing.

FIG. 7 is a configuration diagram showing a configuration of a main part of a photography device according to a third embodiment of the present invention.

FIG. 8 is a waveform diagram for explaining the operation.

FIG. 9 is a block diagram showing a configuration of a main part of a photography device according to a fourth embodiment of the present invention.

FIG. 10 is a schematic configuration diagram of a conventional example.

FIG. 11 is an operation explanatory diagram of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Endoscope device 2 ... Electronic endoscope 3 ... Light source device 4 ... Video processor 5 ... Color monitor 6 ... Photographing device 7 ... Image display device 8 ... Camera 9 ... Release switch 10 ... Control part 12 ... Frame memory 13 Sync signal processing unit 14 Image change switch 16 VGA 17 CRT display unit 21 Average brightness calculation unit 22 Image area calculation unit 23 Exposure control unit 26 Color film 27 Rotation color filter 28 Rotation color filter drive Department

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location H04N 9/79 (72) Inventor Hiroko Oishi 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optics Industry Co., Ltd.

Claims (1)

[Claims] 1. A photographic device for displaying a video signal containing an image on an image display device and taking a picture with an image photographic device, comprising: an average brightness calculating device for calculating an average brightness of the video signal; An area calculating unit for calculating an area of the image capturing apparatus, and an exposure amount when a photograph is taken by the image capturing unit is controlled by the values of the average brightness and the area.