KR100350306B1 - white balance preservation device for electric light board - Google Patents

Abstract

The present invention relates to a white balance maintaining device of a full-color electronic display board which reproduces colors with red, green, and blue devices installed indoors and outside to convey a message to a large crowd or the public, and a temperature for measuring the temperature of the electronic display board. A / D converter for converting analog signal from sensor, temperature sensor into digital signal, Microprocessor outputting luminance correction control signal according to temperature value applied from A / D converter, and image according to control signal of microprocessor Consists of a luminance data converter that increases or decreases the luminance value of the signal, and corrects the luminance values of the red and green light according to the temperature around the display board to maintain a constant white balance. Accurate color reproduction can be performed in winter or summer to display high quality images. It allows.

Description

White balance preservation device for electric light board}

The present invention relates to a white balance maintaining device of a full-color electronic display board which is installed indoors and outside and reproduces colors with red, green, and blue devices that deliver a message to a large crowd or the public.

In general, the display board is composed of a combination of those that control the luminance of each pixel based on the three primary colors of red, green, and blue light, and the display device includes a light emitting diode, a fluorescent lamp, and a discharge tube. Light emitters are used.

However, the light emitting device has a slight difference in the reproduction of colors at high and low temperatures due to the change in luminance or wavelength depending on the ambient temperature, which causes the white balance to collapse.

In general, the display board is set to a white balance at room temperature, so when the temperature change is severe, such as winter or summer, the white balance collapses, causing problems in color reproduction.

SUMMARY OF THE INVENTION An object of the present invention is to provide a white balance maintaining device for maintaining a constant white balance irrespective of ambient temperature to achieve excellent color reproduction at all times.

1 is a block diagram of a signboard device to which a white balance maintaining device according to the present invention is applied;

Figure 2 is a block diagram showing the configuration of an electronic signboard white balance maintaining apparatus according to the present invention,

3 is a detailed view of the data control / line driver of FIG. 2;

4 is a log graph showing a luminance change according to a temperature change of red light,

5 is a log graph showing a change in luminance according to a change in temperature of green light,

6 is a log graph showing a change in luminance according to a change in temperature of blue light.

Explanation of symbols on the main parts of the drawings

70: electronic display board 100: main controller

160: data control / line driver 200: display controller

400: White balance maintenance device 410: Temperature sensor

420: Amplifier 430: A / D Converter

440: luminance correction GPU 450: luminance correction data converter

An object of the present invention is to display an image corresponding to a predetermined video signal and to control the light emission level of the light emitter according to the applied image signal and the power supply means for supplying the required power and the electric signboard composed of a plurality of light emitters combined in a matrix form A display white balance maintenance device of an electronic display device having a display controller for controlling a light emitting device driving means and a light emitting device driving means for displaying an image signal which has undergone a predetermined editing process, the temperature for measuring the temperature of the display board A / D converter for converting analog signal from sensor, temperature sensor into digital signal, Microprocessor outputting luminance correction control signal according to temperature value applied from A / D converter, and image according to control signal of microprocessor A luminance that increases or decreases the luminance value of a signal. It can be achieved by the match white balance-holding device comprising the emitter transducer.

It is desirable to further install an amplifier between the temperature sensor and the A / D converter to amplify the signal output from the temperature sensor.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a signboard device to which a white balance maintaining device according to the present invention is applied, FIG. 2 is a block diagram showing a configuration of a signboard white balance maintaining device according to the present invention, and FIG. 3 is a data control / line of FIG. 2. Detailed view of the driver.

In FIG. 1, image data transmitted through radio waves from a broadcasting device such as a broadcasting center 11 or a relay satellite 12 is received by a satellite antenna 13 or a television tuner 14. Other video data include CD player 15, relay car 16, LDP 17, VTR 18, VCR 19, camera 20, copyer 21, CATV 22 and editing. For example, the various types of image data are input to the video input device 40. Here, the editing computer 30 having the scanner 32, the mouse 34, or the like may directly supply the image data or may repeatedly output the image data input in advance according to the plan.

The video editing device 50 connected to the editing computer 30 and the video input device 40 is a device for editing image data, which not only has an effect of expressing an image but also plays a role of a broadcast transmitter having a function such as a switcher. Do it. The image data thereby is sent to the electronic display board 70 through the video output device 60. Here, the preview monitor 52 connected to the video editing apparatus 50 is for screen monitoring of each image data and shows an image state displayed on the actual display board 70. In addition, the plurality of monitors 42 connected to the video input device serve to display each image data input to the video input device on the screen.

In general, the electric signboard 70 is installed at a high place where the eyes of the public or the audience can be easily seen, and the video editing device 50 is installed in an indoor editing room.

The main controller 100 is connected to the video output device 60. This serves to receive the image data passed through the video output device 60 to control the operation of the display board 70 and its peripheral devices as a whole to finally display the target image on the display board 70. The main controller 100 is connected to the display board 70, the display controller 200, and the power supply means 80, and the temperature sensor 410 is provided at the display board 70. The temperature sensor 410 is for measuring the temperature around the electric sign 70, and corresponds to one component of the present invention. In this case, the electronic sign 70 has a configuration in which light emitters such as LEDs are arranged in a matrix form, and power necessary for displaying image data is obtained through the power supply means 80. The display controller 200, which is provided between the main controller 100 and the display board 70, serves to drive light emitters, such as LEDs, installed in the display board 70 by predetermined units. In addition, a control computer 90 is connected to the main controller 100, which allows an operator to adjust the operation of the main controller 100. In some cases, the modem 92 can be adjusted from a long distance. You can also use it to connect to other computers online.

The configuration of the main controller 100 and the display controller 200 is shown in detail in FIGS. 2 and 3.

As can be seen in FIGS. 2 and 3, the white balance maintaining apparatus 400 according to the present invention includes an A / D converter 430 included in the temperature sensor 410, the amplifier 420, and the main controller 100. And a luminance correction data converter 450 constituting the luminance correction MPU 440 and the data control / line driver 160. Here, the temperature sensor 410 is for measuring the temperature around the electric sign 70, the amplifier 420 is for amplifying the signal of the temperature sensor 410, the A / D converter 430 is the amplifier 420 To convert the analog signal of the amplified temperature sensor 410 into a digital signal. In addition, the luminance correction GPU 440 is used to correct luminance data according to the temperature value of the temperature sensor 410 applied through the A / D converter 430, and the ambient temperature is based on the luminance value at room temperature. If the temperature is lower than, the luminance is relatively higher, so the luminance value should be lowered. On the contrary, if the temperature is higher than the normal temperature, the luminance value is lowered. Therefore, the luminance value should be increased. This will be described in more detail later with reference to FIGS. 4 to 6.

In FIG. 2, the double speed converter 110 of the main controller 100 has a high-precision copper screen detection circuit and a double speed processing unit, which are NTSC-type scanning players 525 lines (effective scanning line 480 lines) on a large screen of a TV or a monitor. ), The scan lines are visible and the shortcomings such as line flicker and line clocking are improved. That is, the double speed converter 110 detects an input interlaced signal of 620,000 pixels in one pixel unit and separates three-dimensional Y / C, and also scan line interpolation and field interpolation. To convert the data to progressive scanning. Accordingly, the horizontal scan athlete is increased to 800 lines, and the red, green, and blue signals are separated and output as sync signals.

In other words, the double speed converter 110 converts an NTSC / PAL standard composite video signal or Y / C video signal into an interlace-noninterlace conversion by digital processing to drastically reduce noise and flicker. This is to help you get a burn. The double speed converter 110 may be embedded in the control computer 90 in some cases, of course.

In the preamplifier / A / D converter 120, the preamplifier removes aliasing noise of each image data of red, green, and blue input to the A / D converter, and adjusts the DC level of the signal and the maximum amplitude of the signal to the A / D converter standard. The A / D converter converts analog, red, green, and blue signals into 8 to 10-bit digital signals. This is because it is a light emitter such as an image display only when each signal is sampled and converted into a digital signal.

The red, green, and blue image data can be controlled by 2 ⁿ levels of luminance gradation when the A / D converter has n-bit resolution, and the number of color reproduction is (2 ⁿ ) ^three .

When sampling and sampling the video signal and converting it into a digital signal, all signals must be controlled by timing signals synchronized with the video synchronization signal to achieve stable display without distortion or vibration of the screen. The signal generator 130 and the timing generator 140.

The signal generator 130 uses the PLL method as a reference signal with the horizontal synchronization signal and the vertical synchronization signal output from the double speed converter 110 as a reference signal to the horizontal synchronization signal to quantize the image data at a frequency of 858 times the horizontal synchronization frequency. (line-locked) and a basic clock generator for generating a synchronous clock for transmitting the image data stored in the frame memory to the display controller 200. The timing generator 140 includes an electronic board ( 70) Generates position selection information data capable of dividing the effective screen data according to the size, and generates a control signal generating device that generates a control signal for operating the display controller 200 in synchronization with the main controller 100. to be.

The timing generator 140 has a timing signal generation circuit and a selection circuit for selecting and controlling a memory block for double memory control, and generates an address signal and a latch signal of the image frame memory 150 to free them. Digital image data converted by the amplifier / A / D converter 120 are sequentially stored in the frame memory 150, and a read address and a transmission sync clock are generated to transfer and record the stored data to the display controller 200. Do it.

The pair of frame memories 150 receive sequentially scanned image data of the double speed converter 110 at 60 frames per second and generate red, green, and blue digital image data output from the preamplifier / A / D converter 120. A device that stores and outputs frame by frame in synchronism with the control signal of 140, adopts the double memory method so that another frame while the video signal of the sequential scanning method of the double speed converter 110 is stored in the frame memory 150 on one side. The memory 150 serves to output the stored image data so that the complete screen display of the sequential scanning method is possible.

The data control / line driver 160 corresponds to the final output terminal of the main controller 100 and transmits the image data of each color transmitted from the frame memory 150 to the display controller 200 of the display board. The digital gamma correction is performed according to the light emission characteristics, and the luminance correction is performed on the other hand, and then the signal is separated by an optocoupler, and then the signal is transmitted for each unit of the display board 70 configured as a unit module.

The electric signboard 70 displaying the actual image is composed of a matrix of light emitters 72 constituting display pixel pixels, which are operated by the display controller 200.

Since the image data of the moving image is large, the main controller 100 cannot scan the entire display board 70. Accordingly, the main controller 100 divides the image data of one frame unit into unit data of the corresponding unit and sends them to each of the plurality of display controllers 200 of the corresponding display unit within one vertical synchronization period. The controller 200 receives and selects only the control signal from the main controller 100 and the image data to be displayed by itself, and alternately stores or displays them through the at least one pair of field memories 240 and the image data values according to the control signal. Is scanned by adjusting the degree of light emission to each pixel, that is, the brightness assigned to the light emitter, and the timing generator 210 generates the clock and address signals necessary for storing them in the field memory 240 or the light emitter driving means 300. Scanning through the image data is displayed on the display board 70. Reference numeral 170 denotes an MPU generating luminance control signals, and 180 denotes a preview monitor.

3 shows a data control / line driver 160 of the main controller 100. The data control / line driver 160 as shown in FIG. 3 serves to transmit various signals of the main controller 100 to the display controller 200. In the data control / line driver 160, data input from the frame memory 150 is input to the data curve converter 162 through the buffer 161, and the data curve converter 162 transmits the input scanning data to the human eye's visibility. And the digital gamma conversion standard data according to the gamma characteristics of the display device. The curve selection signal is composed of 5 bits inputted through another buffer 163. One curve is selected and gamma-converted, and the luminance correction data converter 450 increases or decreases luminance values of red, green, and blue according to a signal applied from the luminance correction GPU 440. The luminance corrected image data in the luminance correction data converter 450 is provided to the power separators 165a and 165b in synchronization with the scan dot clock via the latch driver 164.

The power separators 165a and 165b completely separate the power system of the main controller 100 from the power supply system of the display controller 200 and the display board by using a high speed optocoupler to prevent malfunction of the system due to external obstacles. It serves to make a stable operation, the separated data is commonly supplied to the display controller 200 through the bus of the first transmission driver 166 and the second transmission driver 167. In addition, the first transmission driver 166 and the second transmission driver 167 have a mutual backup function, and the transmission driver 166 or 167 designated by the channel selection signal operates, and the other transmission driver 167 or 166 operates. The output is in a high impedance state.

The various control signals and image data converted by the main controller 100 are used to display the screen of the electronic display board 70. That is, in the case of using the electronic signboard white balance maintaining device 400 according to the present invention, since the image whose luminance value is corrected according to the temperature of the electronic signboard is displayed on the electronic signboard 70, color reproduction is excellent even in summer or winter when temperature changes are severe. Can be achieved.

Here, the electronic sign 70 is composed of a combination of a plurality of display units 200, a plurality of display units 200, and a plurality of module units composed of a light emitting unit 72 and the light emitting unit driving means 300 divided by each unit of the block.

4 is a log graph showing a change in luminance according to a temperature change of red light, FIG. 5 is a log graph showing a change in luminance according to a temperature change of green light, and FIG. 6 is a log graph showing a change in luminance according to a temperature change of blue light. .

As shown in FIG. 4, when the red light value is set as the reference value at 20 ° C., the luminance value increases with decreasing temperature at a temperature lower than that, and the luminance value decreases with increasing temperature at a higher temperature. Able to know. That is, in the summer when the temperature around the signboard is 40 ° C, the luminance value of the red light is maintained at the value of "0.9". In this case, the luminance value of the red light should be increased by "0.1" to achieve normal color reproduction. Of course, when the temperature around the display panel falls below 20 ° C., the luminance value of the red light rises above the reference value, so the reference value should be lowered.

As described above, the luminance value should be increased or decreased according to the characteristics of the luminance according to the temperature change of the green light shown in the graph of FIG. 5, and the luminance value of the blue light, as shown in FIG. 6, is almost unaffected by the temperature change. The luminance does not have to be corrected.

As can be seen from the above description, in the case of using the electronic display white balance maintaining device according to the present invention, the white balance is constant even in the winter or summer when the temperature change is severe as the luminance values of the red light and the green light are corrected according to the temperature of the electronic display board. Accurate color reproduction, which is maintained, can produce high quality images.

Claims (2)

An electric display board comprising a plurality of light emitters combined in a matrix form and displaying an image corresponding to a predetermined video signal, power supply means for supplying necessary power, and light emitter driving means for controlling the light emission level of the light emitter according to an applied video signal. And a display controller for controlling the light emitter driving means, wherein the white balance maintaining apparatus of the electronic display apparatus for displaying an image signal having undergone a predetermined editing process as an image, A temperature sensor for measuring a temperature of the display board; An A / D converter for converting an analog signal applied from the temperature sensor into a digital signal; A microprocessor for outputting a luminance correction control signal in accordance with a temperature value applied from the A / D converter; And And a luminance data converter for increasing or decreasing the luminance value of the image signal according to the control signal of the microprocessor. The apparatus of claim 1, wherein an amplifier for amplifying a signal output from the temperature sensor is further provided between the temperature sensor and the A / D converter.