JP2017134180A - Picture control device, large-sized picture display system and luminance switching method of led display board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable luminance of an LED to be changed in a short time during which screen flickering does not matter, responding to a need for increase in size of an LED display board or high definition.SOLUTION: A picture control device of the present invention includes a plurality of control substrates that edits an LED display signal by multiplying a distribution picture signal to be input by a picture signal distributor by a luminance change signal after subjecting a correction computation to a luminance change signal in accordance with environmental illuminance of an LED display board, using correction data for each of a plurality of LED elements preliminarily developed on a SRAM from a flash memory. The correction data is preliminarily developed on the SRAM from the flash memory to thereby enable a reading time of the correction data be shortened. Thus, the luminance change of the LED display board exceeding one million pixels can be controlled within 16.6 ms per one frame. The luminance change can be performed without causing a person to feel screen flickering.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a video control device, a large video display system, and an LED display panel luminance switching method.

  In baseball stadiums, racetracks, and the like, LED large-sized video devices having a screen composed of a number of light emitting diodes (hereinafter referred to as “LEDs”) are installed outdoors. The illuminance around the large LED video device installed outdoors changes from moment to moment as the weather changes and time passes. In order to ensure the visibility of the screen of the LED large-sized video apparatus installed outdoors, it is necessary to change the brightness of the LEDs constituting the screen of the LED large-sized video apparatus in accordance with the change in ambient illuminance.

  The number of pixels of the conventional LED display panel is less than 500,000 pixels, and the entire LED display panel can be controlled by a single control board. Therefore, it is possible to change the entire brightness of the LED display panel within 16.6 ms within one frame by serial communication such as USB (Universal Serial Bus) from a control PC (personal computer) connected to one control board. It was. When the entire luminance change of the LED display panel is performed within 16.6 ms per frame, the flickering of the screen accompanying the luminance change cannot be recognized by human eyes.

  In Patent Document 1 below, regarding the luminance change of the LED display panel, when changing the luminance according to the ambient brightness, the luminance change amount for changing the luminance stepwise with different change amounts is calculated and calculated. A brightness changing method has been proposed in which the brightness of a plurality of display panels is changed simultaneously based on the brightness change amount.

JP 2007-101756 A

  In the method of changing the brightness of the LED display panel described in Patent Document 1, the number of pixels of the LED display board is less than 500,000 pixels, and the brightness of the entire screen can be changed within one frame.

  In recent years, there has been a demand for larger or higher-definition LED display boards. In particular, in anticipation of the Tokyo Olympics scheduled to be held in 2020, resolution corresponding to full high-definition that displays camera images taken for full high-definition in order to support high-definition television, high-definition, full high-definition, etc. Tend to be required. In order to meet the demand for such an LED display panel with a larger size or higher definition, the number of pixels of the entire LED display panel needs to be 1 million pixels or more.

  However, since the limit of the number of pixels that can be controlled by one control board is about 500,000 pixels, in order to change the brightness of the entire LED display panel exceeding 1 million pixels, a plurality of sheets can be controlled from one control PC. It is necessary to change the brightness by controlling the control board. In order to change the luminance by controlling a plurality of control boards from one control PC by serial communication, the luminance change control does not fit within 16.6 ms per frame, and extends over two frames. In this case, since the luminance of the LED of the entire LED display panel is changed after the third frame, there is a problem that the luminance changing time becomes long and the screen appears to flicker.

  Accordingly, the present invention provides a video control device, a large video display system, and an LED display panel that can change the brightness in a short time without causing a flicker of the screen in response to a demand for a larger or higher definition LED display panel. It is an object of the present invention to provide a luminance switching method.

  The video control apparatus according to the first aspect of the present invention edits a plurality of input video information and uses a plurality of LEDs for controlling a plurality of LED elements constituting a screen of an LED display panel by using an LED display signal including a luminance signal. A video control apparatus for outputting to a control board, wherein a plurality of input video information is converted into a vertical synchronization signal, a video signal whose horizontal synchronization frequency matches an output specification, and is output from the scan converter. When a video signal distributor that distributes the video signal to be output and outputs it as a distributed video signal and a luminance change signal corresponding to the environmental illuminance of the LED display panel are input in advance from the flash memory onto the SRAM. The luminance correction calculation is performed using correction data for each of the plurality of LED elements, and the luminance change signal after the correction calculation is input from the video signal distributor. And having a plurality of control boards for editing the LED display signal by multiplying the image signal.

  A large-sized video display system according to a second aspect includes a plurality of video information input ports, a digital visual interface for a reference signal at the time of changing luminance, a serial interface for inputting a luminance changing signal, and an LED display including the luminance changing signal An image output device that outputs a signal; an illuminance sensor that detects ambient illuminance; and a plurality of LED control boards that change the brightness of the LEDs according to the LED display signal input from the image control device; An image display device, and the video control device previously develops correction data for each of a plurality of LED elements constituting the screen of the LED display panel from the flash memory onto the SRAM, and stores the correction data on the SRAM. The luminance correction calculation is performed using the developed correction data, and the LED display is performed using the luminance change signal after the correction calculation. And wherein the to edit the issue.

  A luminance switching method for an LED display panel according to a third aspect includes an illuminance sensor that detects environmental illuminance and a plurality of LED control boards that perform luminance switching according to an input LED display signal. The illuminance sensor detects the ambient illuminance around the LED display panel, and a brightness change signal corresponding to the ambient illuminance to which a plurality of control boards are input is preliminarily developed from the flash memory onto the SRAM. Using the correction data for each of the plurality of LED elements, a luminance correction calculation is performed, and the luminance change signal after the correction calculation is multiplied by the distribution video signal input from the video signal distributor to obtain the LED display signal. Editing and outputting the LED display signal to the plurality of LED control boards.

  The video control device according to the present invention includes a plurality of LED elements in which a luminance change signal corresponding to the environmental illuminance of the LED display panel is preliminarily developed from the flash memory onto the SRAM in the distributed video signal input by the video signal distributor. It has a plurality of control boards for editing the LED display signal by multiplying the luminance change signal after the correction calculation using each correction data. By developing correction data from flash memory onto SRAM in advance, the correction data read time can be shortened, so that it is possible to control the luminance change of an LED display panel exceeding 1 million pixels within 16.6 ms per frame. Accordingly, it is possible to provide a video control device, a large video display system, and a method for switching the luminance of the LED display panel that can change the luminance without causing the user to feel the flickering of the screen.

It is a figure which shows the system configuration example of the large sized image display system of embodiment of this invention. It is a functional block diagram which shows the outline of the video control apparatus in FIG. It is a figure explaining the control resolution of each control board at the time of mounting three control boards in a picture control device. It is a figure explaining the production | generation method of the LED display signal after the brightness change in a prior art. It is a figure explaining the timing of the brightness | luminance change in a prior art. It is a figure explaining the production | generation method of the LED display signal after the brightness change in embodiment of this invention. It is a figure explaining the timing of the luminance change of embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(System configuration of the embodiment)
FIG. 1 is a diagram showing a system configuration example of a large-sized video display system according to an embodiment of the present invention.

  The large-sized video display system according to the embodiment of the present invention edits a plurality of input video information and outputs an LED display signal including a brightness change signal to, for example, three LED control boards 22a (22), 22b, and 22c. The video control device 10 is provided. In the system configuration example shown in FIG. 1, the number of LED control boards 22 is three. However, the number of LED control boards 22 is increased in accordance with the number of LED pixels that increases as the screen of the LED display panel 20 increases in size or definition. For example, the number may be increased to 4, 5 or the like. Hereinafter, the large-sized video display system will be described assuming that the number of LED control boards 22 is three.

  For example, a running horse and an odds control PC (personal computer) 1 are connected to the video control apparatus 10 by DVI (Digital Visual Interface). The running horse and odds control PC 1 provides the video control apparatus 10 with video information related to the running horse and odds information.

  Further, for example, the camera relay device 2 and the video distribution device 3 are connected to the video control device 10 by HD-SDI (High Definition Serial Digital Interface). HD-SDI is a signal standard that is widely adopted in broadcasting high-definition digital VTRs, and the camera relay device 2 provides, for example, camera images taken for full high-definition to the video control device 10 as video information. Also, the video distribution device 3 provides the video control device 10 with video information having a resolution corresponding to, for example, full high vision.

  In addition, an LED display board 20 is connected to the output side of the video control device 10. The LED display panel 20 includes an illuminance sensor 21 that detects its own environmental illuminance, and a plurality of LED control boards 22a (22), 22b, and 22c that control a plurality of LED elements constituting the screen.

  The video control device 10 and the three LED control boards 22a, 22b, and 22c are connected by signal lines 15a, 15b, and 15c, respectively. An alarm, an illuminance value, and a disconnection detection signal are output from the LED display panel 20 to the video control device 10 via the signal line 15 a, and an LED display signal including a luminance signal is output from the video control device 10 to the LED display panel 20.

  Also, an alarm and disconnection detection signal is output from the LED display panel 20 to the video control device 10 via the signal line 15 b, and an LED display signal including a luminance signal is output from the video control device 10 to the LED display panel 20. An alarm and a disconnection detection signal are output from the LED display panel 20 to the video control device 10 via the signal line 15c, and an LED display signal including a luminance signal is output from the video control device 10 to the LED display panel 20.

  Here, the alarm is failure information in the three LED control boards 22a, 22b, and 22c, and the disconnection detection signal is the disconnection or disconnection location detected in the three LED control boards 22a, 22b, and 22c. It is a signal that informs.

  Further, the video control device 10 controls the luminance change of the LED elements constituting the screen of the LED display panel 20 via the reference signal DVI when changing the luminance and the serial interface such as USB, RS232C, etc. A control PC (personal computer) 5 is connected.

  The control PC 5 takes in the illuminance value input to the video control device 10 via the signal line 15a, and calculates and outputs a luminance change signal corresponding to the illuminance value. The calculation of the luminance change signal according to the illuminance value in the control PC 5 is performed by, for example, a calculation method using a table for converting the illuminance value to the luminance change signal, a conversion formula for converting the illuminance value to the luminance change signal, or the like. .

  Further, the control PC 5 has a function of monitoring the LED display board 20. For example, the control PC 5 outputs a disconnection detection command to the video control device 10 to acquire a disconnection detection signal from the LED display panel 20 and outputs an alarm information acquisition signal to acquire an alarm from the LED display panel 20. .

(Configuration of video control device)
FIG. 2 is a functional block diagram showing an outline of the video control apparatus in FIG.

  The video control apparatus 10 synthesizes, cuts, and converts the resolution of a plurality of input video information, converts the vertical synchronization signal and the horizontal synchronization frequency into a video signal that meets the output specifications, and outputs the video signal. The video signal distributor 12 that distributes the video signal input from the scan converter 11 via the DVI and outputs it as a distributed video signal, and when the luminance change command is issued from the control PC 5, the distributed video signal is multiplied by the luminance change signal. And three control boards 13a (13), 13b, and 13c for editing the LED display signal. The three control boards 13a, 13b, and 13c are connected to the three LED control boards 22a, 22b, and 22c, respectively.

  The control boards 13a, 13b, and 13c are connected to the control PC 5 through a serial interface such as USB. When an instruction to change the luminance is given from the control PC 5 to the control boards 13a, 13b, and 13c, the control boards 13a, 13b, and 13c generate LED display signals including the luminance signals, respectively, and the corresponding LED control boards 22a, 22b, and 22c. Output to. The three LED control boards 22a, 22b, and 22c change the brightness of the corresponding LED elements constituting the screen of the LED display board 20 to the brightness corresponding to the illuminance value detected by the illuminance sensor 21.

A method for generating the LED display signals of the control boards 13a, 13b, and 13c will be described later.
(Operation of the embodiment)
Regarding luminance switching processing in the large-sized video display system of the embodiment of the present invention, (I) control resolution per control board, (II) luminance switching processing in the prior art, and (III) luminance switching in the embodiment of the present invention The process will be described separately.

(I) Control Resolution per Control Board FIG. 3 is a diagram for explaining the control resolution of each control board when three control boards are mounted in the video control apparatus.

  The LED display panel 20 displays, for example, 1280 dots × 1536 dots = 1,966,080 dots in number of LED elements (number of pixels) on the entire screen of the LED display panel 20 in order to display full high-definition video with high definition. Have. Since the number of pixels that can be controlled to change the brightness with one control board is about 500,000 pixels, the entire screen of the LED display panel 20 is divided into three regions, and the three LED control boards 22a, 22b, 22c. When the entire screen of the LED display panel 20 is divided into three regions, the number of LED elements (number of pixels) controlled by each LED control board 22a, 22b, 22c is 1280 dots × 512 dots = 655,360. It becomes a dot.

(II) Luminance Switching Processing in the Conventional Technology FIG. 4 is a diagram for explaining a method for generating an LED display signal after changing the luminance in the conventional technology.

  The control board 30 in the prior art includes a CPU (Central Processing Unit) 31 that controls the entire board and three flash memories (Flash memory) that store correction values of RGB brightness for each pixel of 655,360 dots as correction data. Memory) 32, RGB color gradations, luminance, and arithmetic circuit 33 that generates the LED display signal after the luminance change by multiplying the correction data.

  The arithmetic circuit 33 inputs RGB gradations in the distribution video signal including the vertical synchronization signal VSYNC input from the DVI distributor 12, the luminance input from the control PC 5 via the CPU 31, and the luminance change signal input from the control PC 5 to the CPU 31. Each time the CPU 31 issues a correction data read request to the three flash memories 32, the RGB three-color correction data read and input from the three flash memories 32 are multiplied, and the luminance is changed. LED display signals are generated. The vertical synchronization signal VSYNC is a signal for measuring the timing in the vertical direction when drawing a screen on a television or a display. The brightness of the LED is changed in synchronization with the vertical synchronization signal VSYNC.

  Here, the correction data for each dot is 8 bits, the flash memory 32 is 16-bit data, and the access speed of the flash memory 32 is 25 ns. Since the flash memory 32 is 16-bit access, two dots are read at a time, and correction data for RGB colors are simultaneously read in parallel.

  Since the control resolution per control board is 1280 bits × 512 bits = 655,360, it is necessary to read out correction data for 655,360 dots.

  Accordingly, the correction data read time is 655, 360 × 25 ns ÷ 2≈8.2 ms.

FIG. 5 is a diagram for explaining the timing of luminance change in the prior art.
Next, with reference to FIG. 4 and FIG. 5, the timing of luminance change in the prior art will be described.

  It takes 0.5 ms for the CPU 31 in the control board 30 in FIG. 4 to receive a luminance change signal given by USB communication from a control PC (not shown). As described above, reading correction data requires a time of 8.2 ms, and it takes 0.5 ms for the CPU 31 to return a processing completion response. Therefore, a total processing time of 8.3 ms is required per control board 30.

  Similarly to the first control board 30, the second and third control boards 30 each require a total processing time of 8.3 ms.

  The processing time 8.3 ms corresponding to the first control board 30 is within one frame (16.6 ms) corresponding to 60 Hz, but the processing corresponding to the first control board 30 and two Since there is a blank unprocessed time between the processing corresponding to the control board 30 of the eye, the processing time for changing the luminance of the first and second control boards 30 is 1 frame (16 Within 6 ms). Further, the processing time corresponding to the first to third control boards 30 extends over one frame and two frames.

  The brightness change is executed by switching to the LED display signal after the brightness change in synchronization with the vertical synchronization signal VSYNC of the next frame after the process of reflecting the brightness change signal to the LED display signal. Since the processing corresponding to the first control board 30 is contained in the first frame, the output data of the first control board 30 is switched from the second frame to the LED display signal after the luminance change. On the other hand, the processing corresponding to the second and third control boards 30 extends from the first frame to the second frame. Therefore, in the second frame, the LED display signal before the luminance change remains as it is. Switch from 3 frames to LED display signal after brightness change.

  As described above, when the luminance change is controlled by the LED display signal generation method in the prior art, the luminance change of the LED element corresponding to the first control board 30 in the screen configuring the LED display board 20 is as follows. The brightness change of the LED elements corresponding to the second and third control boards 30 is performed in the third frame, and the screen flickers to the human eyes. End up.

  Hereinafter, the luminance switching process according to the embodiment of the present invention, in which the luminance is switched in a short time without causing the screen flickering, will be described.

(III) Luminance Switching Process in the Embodiment of the Present Invention FIG. 6 is a diagram for explaining a method for generating an LED display signal after a luminance change in the present invention.

  The control board 13 is stored in the flash memory 42, a CPU 41 that controls the entire board, three flash memories 42 that store RGB brightness correction values for each pixel of 655,360 dots as correction data, and so on. Calculation to generate LED display signals after changing the luminance by multiplying three SRAMs (Static Random Access Memory) 43 in which correction data is developed in advance for each RGB color, RGB color gradation, luminance, and correction data. Circuit 44.

  After the power is turned on, the correction data for the three colors RGB stored in the flash memory 42 is developed in the SRAM 43 in advance.

  The arithmetic circuit 44 has RGB gradations in the distribution video signal input from the DVI distributor 12, luminance input from the control PC 5 via the CPU 41, correction data of RGB three colors previously developed in the SRAM 43, To generate an LED display signal after the luminance change.

  Here, the correction data for each dot is 8 bits, the SRAM 43 is 16-bit data, and the access speed of the SRAM 43 is 10 ns. In addition, the SRAM 43 has one RGB color. Since the SRAM 43 is 16-bit access, two dots are read at a time, and correction data for each color of RGB are simultaneously read in parallel.

  Since the control resolution per control board is 1280 bits × 512 bits = 655,360, it is necessary to read out correction data for 655,360 dots.

  Accordingly, the correction data read time is 655, 360 × 10 ns ÷ 2≈3.3 ms.

FIG. 7 is a diagram for explaining the timing of luminance change in the embodiment of the present invention.
Next, with reference to FIG. 6 and FIG. 7, the timing of luminance change in the embodiment of the present invention will be described.

  It takes 0.5 ms for the CPU 41 in the control board 13 in FIG. 6 to receive the luminance change signal from the control PC 5. As described above, reading of the correction data takes 3.3 ms, and it takes 0.5 ms for the CPU 41 to return a processing completion response. A total processing time of 3.4 ms is required for each control board 13a.

  Similarly to the first control board 13a, the second and third control boards 13b and 13c each require a total processing time of 3.4 ms.

  The process corresponding to the first control board 13a is started in synchronization with the vertical synchronization signal VSYNC, the process is completed in 3.4 ms, and the process corresponding to the second control board 13b is performed continuously in the manner of 3. When the process corresponding to the second control board 13b is completed, the process corresponding to the third control board 13c is continuously executed in 3.4ms. As a result, the processing time required to change the luminance of the three control boards 13 is 3.4 ms × 3≈10.2 ms, and the luminance changing process is completed within the first frame of 16.6 ms.

As a result, the output data from the three control boards 13a, 13b, and 13c are simultaneously switched to the LED display signal after the luminance change in synchronization with the vertical synchronization signal VSYNC from the second frame.
(Effect of embodiment)
In the video control apparatus according to the embodiment of the present invention, the distribution data signal includes correction data for each of the plurality of LED elements in which a luminance change signal corresponding to the environmental illuminance of the LED display panel is previously developed from the flash memory onto the SRAM. It has a plurality of control boards for editing the LED display signal by multiplying the luminance change signal after the correction calculation is performed. By developing correction data from flash memory onto SRAM in advance, the correction data read time can be shortened, so that it is possible to control the brightness change of an LED display panel exceeding 1 million pixels within 16.6 ms per frame. Thus, the brightness can be changed without making the user feel flickering on the screen.

  Further, the timing of the LED display signals output from the plurality of control boards to the plurality of LED control boards is such that the first luminance change signal is output in synchronization with the vertical synchronization signal, and the second and subsequent LED control boards are output. On the other hand, the second and subsequent LED display signals are output in succession to the first LED display signal. Thereby, the processing time required for the luminance change can be further shortened.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to embodiment mentioned above, A various structure or embodiment can be taken in the range which does not deviate from the summary of this invention.

1 Start horse, odds control PC
2 Camera relay device 3 Video distribution device 5 Control PC
DESCRIPTION OF SYMBOLS 10 Image | video control apparatus 11 Scan converter 12 DVI distributor 13,13a, 13b, 13c, 30 Control board 20 LED display board 21 Illuminance sensor 22,22a, 22b, 22c LED control board 31,41 CPU
32, 42 Flash memory 33, 44 Arithmetic circuit 43 SRAM

Claims (6)

A video control device that edits a plurality of input video information and outputs an LED display signal including a luminance signal to a plurality of LED control boards that control a plurality of LED elements constituting a screen of the LED display board,
A scan converter that converts a plurality of input video information into a vertical sync signal, a video signal whose horizontal sync frequency meets the output specification, and outputs it,
A video signal distributor that distributes the video signal input from the scan converter and outputs the video signal as a distributed video signal;
When a luminance change signal corresponding to the ambient illuminance of the LED display panel is input, the luminance correction calculation is performed using correction data for each of the plurality of LED elements previously developed from the flash memory onto the SRAM, and the correction is performed. A plurality of control boards for editing the LED display signal by multiplying the calculated luminance change signal by the distributed video signal input from the video signal distributor;
A video control apparatus comprising:   The luminance correction calculation process performed by the first control board of the plurality of control boards is started in synchronization with the first vertical synchronization signal included in the distribution video signal, and the first control board is controlled. The video control apparatus according to claim 1, wherein the luminance correction calculation processing of the second and subsequent control boards is performed continuously after the luminance correction calculation processing performed by the substrate is completed.   The video control apparatus according to claim 2, wherein the process of the correction calculation is generated by multiplying each color tone of RGB of the distribution video signal, luminance, and correction data.   The LED after the luminance change reflecting the processing result of the luminance correction calculation in synchronization with the earliest vertical synchronization signal after the processing of the luminance correction calculation in all the control boards of the plurality of control boards is completed The video control apparatus according to claim 2, wherein a display signal is output from the plurality of control boards. Video having a plurality of video information input ports, a digital visual interface for reference signal at the time of luminance change, a serial interface for inputting the luminance change signal, and an output port for outputting an LED display signal including the luminance change signal A control device;
An LED display board including an illuminance sensor that detects environmental illuminance, and a plurality of LED control boards that change the luminance of the LED according to the LED display signal input from the video control device;
The video control device develops correction data for each of a plurality of LED elements constituting the screen of the LED display panel from a flash memory in advance on the SRAM, and uses the correction data developed on the SRAM. A large-sized video display system which performs a luminance correction calculation and edits the LED display signal using a luminance change signal after the correction calculation. A luminance switching method for an LED display board, comprising: an illuminance sensor that detects environmental illuminance; and a plurality of LED control boards that perform luminance switching according to an input LED display signal,
The illuminance sensor detects the ambient illuminance around the LED display board;
A luminance change signal corresponding to the ambient illuminance inputted by a plurality of control boards is corrected for luminance using correction data for each of the plurality of LED elements previously developed from the flash memory on the SRAM, and the correction calculation is performed. An LED display panel which edits an LED display signal by multiplying a later-mentioned luminance change signal by a distribution video signal inputted from a video signal distributor, and outputs the LED display signal to the plurality of LED control boards Brightness switching method.

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