JPH06217336A - Automatic adjustment system for multi display device - Google Patents

Abstract

PURPOSE:To precisely realize the adjustment taking much time for the multi display device such as the adjustment of a gamma characteristic and white balance automatically in a short time. CONSTITUTION:A camera 11 picks up an image of projection display devices 10a, 10b, 10c, 10d. A frame memory 13 stores an output signal of the camera 11 obtained via arm A/D converter circuit 12. A computing element 14 extracts luminance data at a position of the center of each projection display device from each digital data to be stored to implement ratio calculation or the like. A control circuit 15 uses the result of calculation to control the amplification factor of an amplifier circuit 9 of each projection display device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-display device in which a plurality of projection displays are combined to form one screen, and particularly when such a multi-display device is installed, the white balance and gamma characteristics of the display. The present invention relates to a system for automatically adjusting uneven brightness, uneven color, and the like.

[0002]

2. Description of the Related Art Conventionally, a multi-display device in which a plurality of projection-type displays are combined has a shorter depth and higher brightness than a single large-screen display, and is therefore used in event venues, showrooms and the like.

In the rear projection type system using a CRT, for example, the projection type display has red, green, and
Blue CRT 1 and magnifying projection lens 2 for each CRT
And a transmissive screen 3. The lights from the CRTs 1 for red, green, and blue are magnified and projected by the magnifying projection lens 2 and focused on the transmissive screen 3 to provide an image.

A known example of such an automatic adjusting device for a rear projection type display is, for example, Japanese Patent Laid-Open No. 3-1049.
There is a white balance adjusting device described in Japanese Patent No. 4 publication. This white balance adjustment device arranges a photodetector in the overscan area, detects each light amount of red, green, and blue with the photodetector, obtains the relative light-receiving levels of red, green, and blue, and determines it in advance. The required amount of correction for the cut-off voltage, drive voltage, and gamma correction of the video signal processing circuit is calculated by comparing with a certain reference relative level, and the controller is controlled according to the required amount of correction to adjust the white balance. .

[0005]

The above-mentioned prior art does not consider adjusting a multi-display device in which a plurality of projection displays are combined to form one screen. For example, if there are variations in characteristics among the photodetection elements built in the individual projection displays, the white balance of the individual projection displays varies, and a uniform screen cannot be obtained as a multi-display device. In this case, humans manually perform adjustment between the projection displays, which is very time-consuming as compared with adjustment of a single display.

[0006] On the other hand, in each projection display, generally, there is unevenness in brightness and color such as darkness in the peripheral portion with respect to the center in each display, so that one or a plurality of points in the overscan area are present. There is a problem in that it is difficult to adjust the white balance in the center of the screen even if the red, green, and blue light quantities are measured.

The object of the present invention is to solve the above-mentioned problems of the prior art and to automatically and shortly perform a very time-consuming adjustment, such as a gamma characteristic or white balance adjustment, in a multi-display device. An object of the present invention is to provide an automatic adjustment system that can be realized with high accuracy in time and that can correct unevenness in brightness and color in individual displays.

[0008]

According to the present invention, a camera is arranged in front of a plurality of projection displays, and brightness information at a plurality of locations of a plurality of displays is stored in a frame memory using a single camera. . Necessary data is extracted from the information in the frame memory, and the data are compared and operated. The result is used to control the white balance adjustment circuit, the gamma characteristic correction circuit, and the brightness unevenness correction circuit of each display.

Further, in the present invention, a reference surface light source is provided or a reference display is set among the plurality of displays, and a plurality of light detecting elements are used to adjust the light amount of the reference surface light source or the reference display. The measurement was performed, and the data of the light amount was used as reference data. The reference data and the data obtained by measuring the light intensity of each display using the plurality of photo-detecting elements were compared and calculated for each display or for the previous displays all together. The result is used to control the white balance adjustment circuit and the brightness unevenness correction circuit of each display.

[0010]

In the multi-display automatic adjustment system of the present invention, quantitative brightness data of a plurality of displays can be obtained by the camera or the photodetection element. It enables automatic adjustment of gamma characteristics, white balance, etc. of the display, greatly shortening the adjustment time and improving the adjustment accuracy and reproducibility.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an automatic adjustment system for a multi-display device as a first embodiment of the present invention. FIG. 1 shows an example in which four projection displays are used as the multi-display device. As the projection display, for example, a rear projection display using a CRT as shown in FIG. 5 is used. 4 is a video signal input terminal for inputting red, green and blue analog video signals, 5 is an A / D conversion circuit for converting an analog video signal into a digital video signal, 6 is a signal expansion distributor, and 7 is, for example, A gamma correction circuit composed of a look-up table (hereinafter referred to as LUT), 8 is a D / A conversion circuit for converting the output data of the gamma correction circuit 7 into an analog signal, and 9 is a CRT for the analog signal.
Amplifier circuit for amplifying the voltage to drive
10c and 10d are projection displays. A video signal processing circuit 16 including a gamma correction circuit 7, a D / A conversion circuit 8 and an amplification circuit 9 is provided for each of the red, green and blue signals for each display. 11
Is a camera for measuring the light intensity of a multi-display device, 1
2 is A for converting the output signal of the camera 11 into a digital signal
/ D conversion circuit, 13 is a frame memory for storing the contents of one frame of the digital signal, 14 is the frame memory 1
An arithmetic unit for taking out the contents of 3, performing comparison and arithmetic operation, and a control circuit 15 for controlling the gamma correction circuit 7 and the amplification circuit 9 from the output result of the arithmetic unit 14.

A method of adjusting the gamma characteristic and the white balance in this embodiment will be described below. First, the level of the video signal input to the input terminal 4 is maximized, and the projection displays 10a, 10b, 10
The cameras 11 and 10 are photographed. Camera 1 at this time
The output signal of 1 is stored in the frame memory 13 via the A / D conversion circuit 12. The arithmetic unit 14 extracts the brightness data at the central portion of each projection display from the stored digital data. Here, for example, it is assumed that the projection displays 10a and 10b have video signal level-luminance characteristics as shown in a and b of FIG. 2, respectively. The curves a and b in FIG. 2 do not match, and even if the same signal is input to each projection display, there is a difference in luminance and chromaticity between the projection displays. Therefore, the projection display 10a on the frame memory 13 previously stored
Is different from the data of the projection display 10b. Here, the calculator 14 calculates the ratio of the data of the projection display 10a and the data of the projection display 10b, for example, and the control circuit 15 uses the calculation result to calculate the ratio of the amplifier circuit 9 of the projection display 10a. By lowering the amplification factor, the maximum brightness of the projection displays 10a and 10b can be made to match, as shown in the video signal level-luminance characteristics of FIG.

Similarly to the above, when the maximum brightness of three or more displays is made to coincide with each other, for example, the maximum brightness is displayed on each display, and the data of the display having the minimum brightness is searched, and the maximum brightness is retrieved. Calculate the ratio between the data and the data of each display. By controlling the amplification factor of each amplification circuit 9 of the projection type display using the calculation result, the maximum brightness of all the displays and the color temperature can be made to coincide with each other.

Next, for example, the level of the input video signal to the projection display is changed from low brightness to high brightness, and the projection display 10 is changed by the camera 11 each time.
Images a, 10b, 10c, and 10d are captured, and the four data are captured in the frame memory 13. In the calculator 14,
Of the four data, the display data having the minimum brightness is searched, and the difference between the data showing the minimum brightness and the data of each display is calculated. Control circuit 15
Controls the gamma correction circuit 7 using the calculated data. The gamma correction circuit 7 is composed of, for example, an LUT. That is, the control circuit 15 rewrites the content of the LUT for each gradation based on the difference data, so that the brightness and the color temperature can be matched at all the gradations, as shown in FIG. .

By the above method, the white balance and gamma characteristics of all projection displays are matched by controlling the amplification factor and gamma correction of the video signal according to the calculation result based on the data captured by the camera 11. Can be made. Therefore, uniform display is possible even in a multi-display device in which a plurality of projection displays are combined to form one screen. In the above description, the luminance is used. However, in the present invention, since the gamma correction circuits and the amplifiers for red, green, and blue are separately provided for each projection display, the procedure similar to the above-described adjustment of the luminance level is performed. The white balance can be adjusted.

FIG. 6 shows an example of a liquid crystal display device as another example of the projection display used in the multi-display device of the present invention. The liquid crystal display device of FIG. 6 will be briefly described below. In the liquid crystal display device of FIG. 6, white light from the light source 31 is reflected by the dichroic mirrors 32 and 33 in red, green, and
Separated into blue light, and using the reflection mirrors 34, 35, 36 and 37, liquid crystal panels 38, 39 for red, green and blue, respectively.
It is incident on 40. The liquid crystal panels 38, 39 and 40 change in transmittance depending on the applied voltage. Liquid crystal panel 38, 3
The light transmitted through 9 and 40 is dichroic prism 41.
And is projected on the screen 43 by the magnifying projection lens 42.

In a multi-display device using a plurality of liquid crystal display devices as a projection display,
In this case, the gamma characteristic and the white balance of each liquid crystal display device also vary due to the variation of the transmittance of the liquid crystal panel and the variation of the characteristic. In this case, the same configuration and the same procedure as those of the embodiment of FIG. The white balance and gamma characteristics of the liquid crystal display device can be matched.

FIG. 7 shows an automatic adjustment system for a multi-display device as a second embodiment of the present invention. Figure 1
The same numbers are given to the same items as, and the description is omitted.

FIG. 7 shows the video signal processing circuit 16 of FIG.
This is an example of a multi-display device provided with a luminance unevenness correction circuit 20 including a UT 17, a D / A conversion circuit 18, and a low-pass filter (hereinafter abbreviated as LPF) 19. In this embodiment, the adjustment can be performed without the LPF 19.

The correction of uneven brightness and uneven color in this embodiment will be described below. An example of the signal level of one scanning line is shown in (1) of FIG. 8, and an example of the brightness on the screen in one display when the signal level of (1) is input to the display is shown in (2). As shown in FIG. 8, even if a signal of the same level is input to the edges and the center of the screen, the projection display has a brightness unevenness in which the central part is bright and the peripheral part is dark as shown in (2) of FIG. , CRT arrangement, projection magnifying lens and the like cause uneven color and uneven brightness. The color unevenness and the brightness unevenness are captured by the camera 11 and stored in the frame memory 13 via the A / D conversion circuit 12. The control circuit 15 rewrites the contents of the LUT 17 using the result of comparison calculation of the data in the frame memory 13 by the calculator 14.

FIG. 9 shows an output example of the LUT 17 when the signal level of (1) of FIG. 8 is input to the video signal input terminal 4. For a constant signal level, the LUT 17 converts the dark part as it is and the bright part as small data. The output data of the LUT 17 is converted into an analog voltage on the stairs by the D / A conversion circuit 18, and is used as the reference voltage of the D / A conversion circuit 8 via the LPF 19. Since the output voltage of the D / A conversion circuit 8 changes according to the reference voltage of the D / A conversion circuit 8, the video signal input to the projection display can be changed in accordance with the brightness unevenness. The brightness of can be made uniform.

In order to perform the above correction on all the data of the video signal, an LUT having a very large capacity is required. Therefore, the unevenness in brightness and the unevenness in color depending on the projection position can be corrected to some extent by dividing into several blocks and correcting each block as shown in FIG. 10, for example. In this case, the analog voltage on the stairs
By smoothing with 19 and using it as the reference voltage of the D / A conversion circuit 8, the video signal input to the projection display can be smoothly changed according to the uneven brightness, and the brightness within the projection display is made uniform. be able to. With such a correction method, although the correction accuracy is somewhat degraded, the LUT
The capacity can be reduced, the system scale can be reduced, and the price can be reduced.

The automatic adjustment system for the multi-display device using the camera 11 has been described above. In addition,
The camera 11 used in this system may be a camera that can output luminance information as a signal, such as a video camera or an electronic still camera. By the way, in such an automatic adjustment system for a multi-display device using the camera 11, the camera 11 itself has uneven sensitivity, and it is necessary to correct this in advance.

Then, a specific example for correcting the sensitivity unevenness of the camera itself will be described with reference to FIG. Camera 11, A / D conversion circuit 12, frame memory 13
Are the same as in FIGS. 1 and 7. Reference numeral 46 is a surface light source having a uniform brightness over the entire surface. First, the surface light source 46 is connected to the camera 1.
1, and the surface light source data is loaded into the frame memory 13 via the A / D conversion circuit 12. Based on this data, for example, similar to the brightness unevenness correction of the display described with reference to FIG. 6, the LUT 48 performs a comparison operation by the operation unit 14 so that the output signal voltage of the A / D conversion circuit 12 becomes constant.
The D / A conversion circuit 49 and the correction circuit 51 composed of the LPF 50 control the reference voltage of the A / D conversion circuit 12.
The detailed description is omitted because it is the same as that in FIG. By correcting the sensitivity unevenness of the camera itself in this way,
The brightness of the multi display can be measured correctly.

Further, another specific example of the circuit for correcting the sensitivity unevenness of the camera itself will be described with reference to FIG. In FIG. 12, a memory 52 is provided instead of the correction circuit 51. In FIG. 12 as well, as in FIG.
And the frame memory 1 through the A / D conversion circuit 12
The data of the surface light source is loaded into 3. In this method, based on this data, the correction data is created by the calculator 14 and stored in the memory 52. When adjusting the projection display,
White balance, uneven brightness, and the like are corrected using the result of calculating the data in the frame memory 13 when the projection display is photographed by the camera 11 and the correction data in the memory 52. With this method, it is possible to correct unevenness in the sensitivity of the camera itself with a circuit simpler than the adjustment method shown in FIG.

In addition to the above-mentioned surface light source, for example, it is possible to correct the unevenness in sensitivity of the camera itself even if it is used in a clear sky or a display that is precisely adjusted. Further, as shown in FIG. 13, one small surface light source 53 is moved within the camera capturing range, and the brightness of the surface light source at each position is sequentially captured by the camera 11.
With the same configuration as described above, the sensitivity unevenness of the camera itself is corrected.
By doing so, it is possible to correct the sensitivity unevenness of the camera itself by using a small surface light source that can be formed relatively easily.

It is preferable that the white balance of the camera 11 is adjusted to match the white balance of the projection display, but even if the white balance of the camera 11 and the projection display are different, the white balance may be adjusted depending on the chromaticity of each white balance. Adjustment is possible by using a conversion formula.

Further, in the frame memory 13 shown in FIGS. 1 and 6, a plurality of frame memories are used and the average value of the data thereof is taken to eliminate noise components and improve the measurement accuracy. You can Further, even with a single frame memory, it is possible to improve the measurement accuracy by sequentially calculating the captured data.

FIG. 14 shows an automatic adjustment system for a multi-display device as a third embodiment of the present invention. FIG. 14 shows an example in which four projection displays are used as the multi-display device, as in FIG. Figure 1
7 and those similar to FIG. 7 are designated by the same reference numerals, and the description thereof will be omitted. 23 is a photodetector, 24 is a multiplexer, 25 is an A / D conversion circuit, 26 is a switch, 27, 2
8 is a frame memory, 29 is a computing unit, 30 is a computing unit 2
A control circuit for controlling each circuit in the video signal processing circuit 22 based on the calculation result of 9.

The method for adjusting the luminance unevenness in this embodiment will be described below with reference to FIGS. 15 and 16. In FIG. 15, reference numeral 45 is a reference surface light source, 23 is the photodetector of FIG. 14, and 44 is a photodetector element constituting the photodetector 23. The photodetector 23 has, for example, a box shape so as to block outside light. The reference surface light source 45 is a light source designed to have the same color temperature and the same brightness over the entire surface. The color temperature of the reference surface light source 45 varies depending on the display to be adjusted,
For example, when adjusting a projection display, set the white color temperature to 9300K. First, the photodetector 23 detects the red, green, and blue light amounts of the reference surface light source 45, respectively, and stores them as reference data in the first frame memory 27 via the multiplexer 24 and the A / D conversion circuit 25 of FIG. To do. Next, as shown in FIG. 16, the red, green, and blue light amounts of one projection display including the CRT 1, the magnifying projection lens 2, and the screen 3 are measured using the same photodetector 23 as in FIG. Detect and Multiplexer 2 of FIG.
4 and the A / D conversion circuit 25, and stores it in the second frame memory 28.

Next, the data stored in the first frame memory 27 and the second frame memory 28 are shown in FIG.
The calculation unit 29 is used for comparison and calculation, and for example, each difference data is output. The control circuit 30 controls the luminance nonuniformity correction circuit 20 based on the difference data, for example, in the same manner as described with reference to FIG. 7. It is possible to correct the unevenness in brightness by sequentially performing the above work for all projection displays.

As the reference surface light source 45, first, a low-brightness reference surface light source is used to perform the same processing as the above-described correction of the brightness unevenness, except that the control circuit 30 controls the brightness unevenness correction circuit 20. The white balance can be adjusted by controlling the cutoff voltage and drive voltage of the projection display, and then using the high-intensity reference surface light source and performing the same processing.

As described above, the reference data is created by using the reference surface light source. However, even if there is no reference surface light source, one projection type display among a plurality of projection type displays can be manually adjusted for white balance and luminance unevenness. If adjusted to, it can also be used as the reference surface light source.

Further, in this embodiment, a liquid crystal display device as shown in FIG. 6 may be used as the projection display.

Further, in this embodiment, since the adjustment accuracy does not change depending on the outside light and the characteristic of the photodetector is not required to be adjusted, it is not possible to make the surroundings dark or the ambient temperature is high. However, accurate adjustment is possible.

[0036]

As described above, according to the automatic adjustment system of the present invention, in the multi-display device,
It is possible to realize extremely time-consuming adjustment automatically and in a short time with high accuracy. In addition, it is possible to correct uneven brightness and uneven color in each display.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an automatic adjustment system for a multi-display device as a first embodiment of the present invention.

FIG. 2 is a characteristic diagram showing an example of gradation-luminance characteristics of the two projection displays in FIG.

FIG. 3 is a characteristic diagram showing an example of gradation-luminance characteristics when only the maximum luminance of the two projection displays in FIG. 1 is adjusted.

4 is a characteristic diagram showing an example of gradation-luminance characteristics when the gamma characteristics of the two projection displays in FIG. 1 are adjusted.

FIG. 5 is a configuration diagram showing a rear projection display using a general CRT.

FIG. 6 is a configuration diagram showing a general liquid crystal display device.

FIG. 7 is a configuration diagram showing an automatic adjustment system for a multi-display according to a second embodiment of the present invention.

FIG. 8 is an explanatory diagram showing luminance unevenness with respect to a signal level of a rear projection display.

FIG. 9 is an explanatory diagram showing an output example of the LUT in FIG.

10 is an explanatory diagram showing another output example of the LUT in FIG. 7. FIG.

FIG. 11 is a configuration diagram showing a specific example of a circuit for correcting the sensitivity unevenness of the camera itself in FIG. 1 or FIG. 7.

FIG. 12 is a configuration diagram showing another specific example of the circuit for correcting the sensitivity unevenness of the camera itself in FIG. 1 or FIG. 7.

13 is an explanatory diagram showing an arrangement example of small surface light sources used in place of the surface light source in FIG. 11 or FIG.

FIG. 14 is a configuration diagram showing an automatic adjustment system for a multi-display as a third embodiment of the present invention.

FIG. 15 is an explanatory diagram showing a state in which the light amount of the reference surface light source is detected by the photodetector in FIG.

16 is an explanatory diagram showing how the photodetector in FIG. 10 detects the light amount of the projection display.

[Explanation of symbols]

1 ... CRT, 2,42 ... Enlargement projection lens, 3,43 ... Screen, 4 ... Video signal input terminal, 5,12,25 ... A
/ D conversion circuit, 6 ... Enlargement distributor, 7 ... Gamma correction circuit,
8, 18 ... D / A conversion circuit, 9 ... Amplification circuit, 10a, 10
b, 10c, 10d ... Projection type display, 11 ... Camera,
13, 27, 28 ... Frame memory, 14, 29 ... Operation unit, 15, 30 ... Control circuit, 17 ... Look-up table, 19 ... Low-pass filter, 20 ... Luminance unevenness correction circuit, 23 ... Photodetector, 24 ... Multiplexer , 31 ... Lamp, 32, 33 ... Dichroic mirror, 34, 3
5, 36, 37 ... Reflective mirror, 38, 39, 40 ... Liquid crystal panel, 41 ... Prism, 44 ... Photodetector, 45 ...
Reference surface light source.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Fumio Inoue, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Inside Video Media Research Laboratories, Hitachi, Ltd. (72) Kunihiko Kondo, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi, Ltd. Information & Video Media Division

Claims (14)

[Claims] 1. A distributor that distributes one input digital video signal into a plurality of digital video signals, and conversion data is stored in each of the distributors and the levels of the plurality of distributed digital video signals are stored. A plurality of first memories for converting based on the conversion data, and a plurality of first digital / analog (hereinafter,
D / A conversion circuits for red, green, and blue, respectively, and the analog signals output from the plurality of first D / A conversion circuits are input to display color images. For a multi-display device having a plurality of projection displays and combining the plurality of projection displays to form one large-screen display, the amount of red, green, and blue light from the plurality of projection displays For detecting the camera, an analog / digital (hereinafter referred to as A / D) conversion circuit for converting the detection signal of the camera into a digital signal and outputting the digital signal, and a digital signal output from the A / D conversion circuit Is provided as a data, a comparison / calculation means for comparing and calculating the data stored in the second memory, and a control means are provided. The means feedback-controls the conversion data stored in the plurality of first memories and the drive voltage of the plurality of projection displays based on the comparison and calculation results of the comparison / calculation means. An automatic adjustment system for a multi-display device characterized by adjusting white balance and gamma characteristics of each projection display. 2. The automatic adjustment system for a multi-display device according to claim 1, wherein each of the plurality of first memories comprises a look-up table. . 3. The automatic adjustment system for a multi-display device according to claim 1, wherein the second memory is a frame memory. 4. The automatic adjustment system for a multi-display device according to claim 1, 2, or 3, wherein:
An automatic adjustment system for a multi-display device, wherein the memory stores data obtained by averaging a plurality of frames of detection signals of the camera as the data. 5. The automatic adjustment system for a multi-display device according to claim 1, 2, 3 or 4, wherein the multi-display device has a third memory for storing luminance unevenness correction data, and the third memory. And a second D / A conversion circuit for converting the luminance nonuniformity correction data stored in to the analog voltage and outputting the analog voltage.
A plurality of brightness unevenness correction circuits for respectively correcting brightness unevenness and color unevenness by using the analog voltage output from the / A conversion circuit as a reference voltage of the plurality of first D / A conversion circuits, The control means is provided for red, green, and blue respectively, and the control means performs feedback control of the brightness unevenness correction data stored in the plurality of third memories based on the comparison and calculation results of the comparison / calculation means. An automatic adjustment system for a multi-display device characterized by: 6. The automatic adjustment system for a multi-display device according to claim 5, wherein each of the third memories in the plurality of brightness unevenness correction circuits is formed of a lookup table. Display device automatic adjustment system. 7. The automatic adjustment system for a multi-display device according to claim 5, wherein the plurality of brightness unevenness correction circuits each include a low-pass filter circuit at an output stage of the second D / A conversion circuit. An automatic adjustment system for a multi-display device, characterized in that the output voltage of each low-pass filter circuit is used as a reference voltage for a plurality of the first D / A conversion circuits. 8. The automatic adjustment system for a multi-display device according to claim 1, further comprising a third memory,
In advance, the comparison / calculation means compares and calculates the data stored in the second memory when the amount of light from the reference surface light source is detected by the camera, and all the data have the same level. An automatic adjustment system for a multi-display device, wherein sensitivity unevenness correction data that can be converted into data is formed and stored in the third memory. 9. The automatic adjustment system for a multi-display device according to claim 1, wherein a third memory for storing sensitivity unevenness correction data and the sensitivity unevenness correction data stored in the third memory are converted into analog voltage. And a second D / A conversion circuit for converting and outputting the analog voltage output from the second D / A conversion circuit by low-pass filtering and outputting the analog voltage. And a low-pass filter circuit, which compares and calculates the data stored in the second memory when the comparison / calculation unit detects the light amount from the reference surface light source by the camera in advance. Then, the control means outputs the sensitivity unevenness correction data stored in the third memory from the A / D conversion circuit based on the comparison and calculation results of the comparison / calculation means. An automatic adjustment system for a multi-display device, characterized in that feedback control is performed so that the levels of the digital signals are equal. 10. The automatic adjustment system for a multi-display device according to claim 8, wherein the detection of the light amount from the reference surface light source performed by the camera is performed by setting the position of the reference surface light source within a capturing range of the camera. And an amount of light from the reference surface light source at each position at that time is detected by the camera, respectively. 11. A distributor for distributing one input digital video signal to a plurality of digital video signals, and stores conversion data, and stores the levels of the plurality of distributed digital video signals. A plurality of first memories for converting based on the converted data, and a plurality of first D / A conversion circuits for respectively converting the plurality of converted digital video signals into analog signals and outputting the analog signals, A second memory for storing the brightness unevenness correction data, and the brightness unevenness correction data stored in the second memory are converted into an analog voltage and output, and the analog voltage is output as a plurality of the first D / A plurality of brightness unevenness correction circuits configured by a second D / A conversion circuit which is a reference voltage of the A conversion circuit;
A plurality of projection-type displays are provided for green and blue, respectively, and the analog signals output from the plurality of first D / A conversion circuits are input, and a plurality of projection-type displays that respectively display color images are provided. For a multi-display device that combines the projection displays to form one large-screen display, a plurality of photo-detecting elements arranged in a matrix and each detecting the amount of light, and a plurality of the photo-detecting elements are detected. A multiplexer that converts a voltage into a time-series voltage and outputs the voltage, an A / D conversion circuit that converts the voltage output from the multiplexer into a digital signal and outputs the digital signal, third and fourth memories, and the third memory And a switch for selecting one of the fourth memory and storing the digital signal output from the A / D conversion circuit in the selected memory as data. Comparing and calculating the data stored in the third memory and the data stored in the fourth memory, and a control means, and a plurality of photodetection elements When the light amount from the reference surface light source is detected by the switch, the switch selects the third memory, stores the light amount data from the reference surface light source in the third memory as the data, and stores a plurality of data. When the light amount from the projection display is detected by the light detection element of, the switch selects the fourth memory, and the light amount data from the projection display is stored in the fourth memory as the data. Let's store, then
The control means compares the drive voltage and the cutoff voltage of the projection display and the brightness nonuniformity correction data stored in the plurality of second memories based on the comparison and calculation results of the comparison / calculation means. An automatic adjustment system for a multi-display device characterized by feedback control. 12. The automatic adjustment system for a multi-display device according to claim 11, wherein a plurality of the first adjustment devices are provided.
An automatic adjustment system for a multi-display device, characterized in that each of the memories is composed of a lookup table. 13. The automatic adjustment system for a multi-display device according to claim 11, wherein the plurality of brightness unevenness correction circuits each include a low-pass filter circuit at an output stage of the second D / A conversion circuit. The output voltage of each low-pass filter circuit, and a plurality of the first D / A
An automatic adjustment system for a multi-display device, wherein the reference voltage of a conversion circuit is used. 14. The automatic adjustment system for a multi-display device according to claim 11, wherein one of the plurality of projection displays is used as the reference surface light source. Adjustment system.