KR20050049658A - Apparatus for controlling color of field emission display panel - Google Patents

Abstract

The present invention detects a high voltage applied to an anode electrode and adjusts a gain of input image data according to the detected high voltage level, thereby maintaining a constant color and color coordinates of a screen, thereby improving image quality. A color compensating apparatus for a panel, the color compensating apparatus for a field emission display panel having a data processing unit for receiving a digital signal displayed on a panel and outputting predetermined data, the apparatus comprising: detecting an anode voltage applied to the panel; According to the detected anode voltage value, a digital signal whose gain of externally inputted R, G, B image data is adjusted or a digital signal whose average value of the entire screen is adjusted for the R, G, B image data is adjusted. By including the color correction control unit output to the processing unit, the color and color coordinates are different depending on the anode voltage To prevent, it has an effect to improve the picture quality by maintaining a constant color and color coordinates of the screen.

Description

Color correction device for field emission display panel {APPARATUS FOR CONTROLLING COLOR OF FIELD EMISSION DISPLAY PANEL}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color correction device for a field emission display panel, and in particular, by detecting a high voltage applied to an anode electrode and adjusting gain of input image data according to the detected high voltage level, thereby adjusting color and color coordinates of a screen. The present invention relates to a color correction apparatus for a field emission display panel which can be kept constant to improve image quality.

Recently, various flat panel displays have been developed to reduce weight and volume, which are disadvantages of cathode ray tubes (CRT). Among such flat panel displays, there is a field emission display (FED), which emits electrons by applying a predetermined electric field to the upper and lower electrodes of the cathode of the FED. It is a device that displays predetermined information using the former.

1 and 2 show a cross-sectional view of a typical FED cell and a plan view of a FED panel composed of the FED cell. As shown, the upper glass 8 includes an anode electrode 7 for applying a high voltage to the cell, a high voltage terminal 9 for applying a high voltage to the anode 7, and a predetermined image. Comprising a phosphor layer (R, G, B) (6) for display, the lower glass (1) generates a scan (cathode) electrode (2) as a source for emitting electrons (e), and generates electrons A data (gate) electrode 4, which is a trigger electrode, to insulate the scan electrode 2 and the data electrode 4, an upper plate 8, and a lower plate glass It consists of a spacer 5 which keeps the space of 1) constant.

In this case, the anode electrode is composed of a top electrode made of one metal plate to apply a high voltage to the display device as a whole.

Looking at the operation of the FED configured as described above are as follows. When a predetermined voltage is applied between the data electrode 4 and the scan electrode 2, electrons are emitted from the scan electrode 2, and the electrons are insulated from the insulating layer 3 and the data electrode by a quantum mechanical tunnel effect. It is discharged through (4).

The emitted electrons e are accelerated toward the anode to which the phosphor layer 6 is applied by a larger anode voltage (hundreds of V to several KV) applied to the anode electrode 7 through the high voltage terminal 9, When the accelerated electrons collide with the phosphor layer 6, electrons of a specific element in the phosphor are excited by the impacted energy and fall off to generate light to display an image.

Generally, high voltage of 4 ~ 5KV or more is applied to the anode electrode in order to maintain the efficiency and lifetime of the FED phosphor. However, the gap between the top glass and the bottom glass is very low. There is. In order to solve this problem, when a low voltage or a medium voltage is applied to the anode electrode, but the voltage applied to the anode electrode is lowered, as described above, the phosphor cannot be properly performed.

In addition, since the efficiency of the phosphor is changed by the high voltage applied to the anode electrode when driving the FED, the brightness, color, and color coordinates of the screen differ from the actual screen.

As such, the efficiency and lifespan of the phosphor and the color and color coordinates of the screen vary according to the voltage of the anode electrode applied to the FED. These problems can be solved by automatically controlling and compensating the input image signal regardless of the anode voltage. However, it is difficult in reality because the anode voltage has more influence on the actual screen and image quality.

As described above, the conventional field emission display panel has a problem in that the brightness, color, and color coordinates of the screen differ from the actual screen because the efficiency of the phosphor is changed by the high voltage applied to the anode electrode during driving.

Accordingly, the present invention in consideration of such a problem, by detecting the voltage applied to the anode electrode, by controlling the gain control or the overall average value of the image data input from the outside using the detected voltage, the color and color in accordance with the anode voltage It is an object of the present invention to provide a color correction apparatus for a field emission display panel which prevents the coordinates from changing and improves image quality by maintaining a constant color and color coordinates of the screen.

According to an aspect of the present invention, there is provided a color correction apparatus for a field emission display panel including a data processing unit for receiving a digital signal displayed on a panel and outputting predetermined data, wherein the anode voltage is applied to the panel. A digital signal in which gains of R, G, and B image data are externally adjusted according to the detected anode voltage value, or a digital signal in which an average value of the entire screen of the R, G and B image data is adjusted. And a color correction control unit for outputting the data processing unit.

The color correction controller may further include: a feedback resistor for lowering an anode voltage applied to the panel to a predetermined voltage; A comparator for comparing predetermined voltages inputted through the feedback resistors with preset reference values and outputting predetermined digital data; A gain controller for outputting a plurality of control signals for controlling gains or total average values for R, G, and B image data input from the outside by predetermined digital data output from the comparison unit; The data processor outputs a digital signal whose gain of R, G, and B image data is adjusted by a predetermined control signal output from the gain control unit, or a digital signal whose average value of the entire screen of the R, G, and B image data is adjusted. And a data converter configured to output the data.

The data converter may further include: a gain unit configured to adjust gains of R, G, and B image data externally input by a predetermined control signal output from the gain controller; And an analog-to-digital converter configured to convert the R, G, and B image data whose gains are adjusted by the gain unit into digital signals and output the digital signals to the data processor.

The data converter may further include: a gain unit configured to output a predetermined adjusted gain of R, G, and B image data input from an external device; An analog-to-digital converter configured to convert R, G, and B image data whose gain output from the gain unit is adjusted to a digital signal and output the digital signal; And a gamma correction lookup table for outputting a digital signal output from the analog-digital converter by a predetermined control signal output from the gain controller to a data processor. It features.

A preferred embodiment of the color correction apparatus of the field emission display panel according to the present invention having the above characteristics will be described with reference to the accompanying drawings.

3 is a block diagram showing the configuration of the color correction device of the field emission display panel of the present invention. As illustrated, the controller 40 outputs a plurality of switching control signals, and the data processor 20 outputs predetermined data based on an externally input digital signal and a switching control signal output from the controller 40. And a data driver 30 for receiving predetermined data output from the data processor 20 and outputting data pulses, and a scan for outputting scan pulses by a predetermined switching control signal output from the controller 40. The driver 50 detects the data pulse, the scan pulse, and the anode voltage input to the anode electrode (not shown), and displays a panel 60 for displaying an image and an anode voltage applied to the panel 60. According to the detected anode voltage value, the digital signal whose gain of externally inputted R, G, B image data is adjusted or the average value of the entire screen for the R, G, B image data is The color correction controller 100 outputs the adjusted digital signal to the data processor 20.

The color correction controller 100 may include feedback resistors R1 and R2 for lowering the anode voltage applied to the panel 60 to a predetermined voltage, a predetermined voltage input through the feedback resistor, and a predetermined reference value (not shown). Gain or total for the R, G, and B image data input externally by the comparison unit 80 for comparing predetermined time) and outputting predetermined digital data and the predetermined digital data output from the comparing unit 80; A gain control part 70 for outputting a plurality of control signals (gain control signal or arithmetic control signal) for controlling the average value, and R, G, whose gain is adjusted by a predetermined control signal output from the gain control part 70; And a data converter 10 for outputting the digital signal for the B image data or the digital signal whose average value of the entire screen is adjusted to the data processor 20.

4 is a block diagram illustrating a detailed configuration of R image data input by the color correction controller. As shown, the image data whose gain is adjusted by the gain control signal for the R image data received from the R converter data (R input) externally input to the data converter 10 and output from the gain controller 70. The R gain unit 11 for outputting the digital signal, and the analog digital converter 12 for converting the R image data of the gain controlled from the R gain unit 11 is converted into a digital signal and output to the data processing unit 20 In this configuration, color and color coordinates are controlled by adjusting gain of analog image data input from the outside according to the anode voltage.

Then, the operation of the present invention having such a configuration will be described in detail with reference to the color correction controller.

First, the anode voltage applied to the panel 60 is lowered to a predetermined voltage using the feedback resistors R1 and R2, and the comparison unit 80 compares the predetermined down voltage with a predetermined reference value to determine a predetermined digital value. Output the data. For example, assuming that the digital data output from the comparator 80 is 5 bits, the digital data output from the comparator 80 is "10000" when the anode voltage is 0 to 1KV, and is "1 to 2KV." 01000 ", 2 to 3KV," 00100 ", 3 to 4KV," 00010 ", and 4KV or more," 00001 ".

The gain controller 70 receives the digital data output from the comparator 80 and outputs an R gain control signal for the digital data. The R gain unit 11 outputs R image data whose gain is predetermined by the R gain control signal output from the gain control unit 70.

The analog-to-digital converter 12 converts the R image data having the predetermined predetermined gain into a digital signal and outputs the digital signal to the data processor 20.

Through this process, the gain of the R image data input is adjusted according to the anode voltage, and the color and color coordinates may be kept constant through the adjusted gain.

Of course, the gain control process for the G image data and the B image data is also the same except that the control signal output from the gain controller 70 is different during the gain control process for the R image data, and the gain control for the G image data is different. The process is briefly described as follows.

The G gain unit (not shown) into which the G image data is input is controlled by the G gain control signal output from the gain control unit 70 to output the G image data whose gain is adjusted, and the output G image data is analog. The digital signal is converted into a digital signal through the digital converter 12 and input to the data processor 20. Through this process, the color and color coordinates of the image data applied to the panel 60 are kept constant regardless of the change of the anode voltage, thereby improving image quality.

The reason why the gain control signals for the R, G, and B image data that are output from the singer gain control unit 70 is different is that the efficiency of the R, G, and B phosphors according to the anode voltage is different. The gain control signal to be output may be an analog or digital signal.

FIG. 5 is a block diagram illustrating a detailed configuration of another embodiment of R image data input by the color correction controller shown in FIG. As shown, the gain control unit 70 receives the digital data output from the comparison unit 80, the logic control unit 81 for outputting a predetermined logic control signal for the anode voltage, and the logic control unit 81 And a calculation control section 82 for outputting a calculation control signal for controlling the total value of the image data input by the logic control signal output from the data conversion section 10. The data conversion section 10 An R gain unit 11 that adjusts and outputs a gain of an R image data (R input) that is externally input, and an analog-to-digital converter 12 that converts and outputs the R image data having a predetermined adjusted gain into a digital signal; ) And a digital signal whose gamma (γ) value is corrected by a calculation control signal output from the arithmetic control unit 82 from the digital signal output from the analog-digital converter 12 to the data processing unit 20. It is constituted by including a gamma correction look-up table unit 13, which, to adjust the color and color coordinates, rather than controlling the value of each pixel increase the overall value of the image data that is input or lowering through the change in the average value.

Compared to the operation illustrated in FIG. 4, the operation of FIG. 5 does not control the input R, G, and B image data according to the anode voltage as pixels, but through the gain unit 11 and the analog-digital conversion unit 12. The difference is that the overall value of the digital signal of the image data whose output gain is adjusted is controlled using the gamma correction look up table.

As described above, the present invention detects the anode voltage, and controls the gain for the R, G, and B image data respectively inputted according to the detected anode voltage value, or controls the value of the entire screen for each image data, thereby controlling color and color. Make the coordinates constant. That is, according to the present invention, the color and the color coordinates have the same image quality regardless of the change of the anode voltage which has the greatest influence on the color and the color coordinates.

As described in detail above, the present invention detects the voltage applied to the anode electrode, and controls the gain control or the overall average value of the image data input from the outside by using the detected voltage, whereby the color and color coordinates are changed according to the anode voltage. It prevents the change and maintains the color and color coordinates of the screen to improve the image quality.

1 is a cross-sectional view showing a cell structure of a typical FED.

Figure 2 is a plan view showing the overall connection structure of the FED panel.

3 is a block diagram showing a configuration of a color correction device of the field emission display panel of the present invention;

FIG. 4 is a block diagram showing a detailed configuration of an embodiment of the color correction control unit of FIG.

FIG. 5 is a block diagram showing a detailed configuration of another embodiment of the color correction controller of FIG.

** Description of the symbols for the main parts of the drawings **

10: Data conversion section 11: R gain section

12: Analog digital conversion unit 13: Gamma correction lookup table unit

20: data processing unit 60: panel

70: comparison unit 80: gain control unit

81: logic control unit 82: operation control unit

100: color correction control unit

Claims (4)

In the color correction apparatus of the field emission display panel having a data processing unit for receiving a digital signal displayed on the panel and outputting predetermined data, Detects the anode voltage applied to the panel and adjusts the gain of the R, G, B image data input externally according to the detected anode voltage value, or the entire screen for the R, G, B image data. And a color correction controller for outputting a digital signal whose average value is adjusted to the data processor. The display device of claim 1, wherein the color correction controller comprises: a feedback resistor for lowering an anode voltage applied to the panel to a predetermined voltage; A comparator for comparing predetermined voltages inputted through the feedback resistors with preset reference values and outputting predetermined digital data; A gain controller for outputting a plurality of control signals for controlling gains or total average values for R, G, and B image data input from the outside by predetermined digital data output from the comparison unit; The data processor outputs a digital signal whose gain of R, G, and B image data is adjusted by a predetermined control signal output from the gain control unit, or a digital signal whose average value of the entire screen of the R, G, and B image data is adjusted. And a data converter configured to output the data to the color correcting apparatus of the field emission display panel. The apparatus of claim 2, wherein the data converter comprises: a gain unit configured to adjust gains of R, G, and B image data externally input by a predetermined control signal output from the gain controller; And an analog-to-digital converter for converting the R, G, and B image data whose gains are adjusted by the gain unit into digital signals and outputting the digital signals to the data processing unit. The apparatus of claim 2, wherein the data converter comprises: a gain unit configured to adjust and output a gain of R, G, and B image data input from an external device; An analog-to-digital converter configured to convert R, G, and B image data whose gain output from the gain unit is adjusted to a digital signal and output the digital signal; And a gamma correction lookup table for outputting a digital signal output from the analog-digital converter by a predetermined control signal output from the gain controller to a data processor. A color correction device for a field emission display panel.