KR20080083950A - Driving apparatus for display device and apparatus for setting gamma including the same - Google Patents

Abstract

A driving device for a display apparatus and an apparatus for setting gamma including the same are provided to reduce work time by setting a gamma voltage based on a voltage difference between a common voltage and a gray scale voltage. A driving device for a display apparatus includes a voltage generator(240), a gamma voltage generator(250), a digital/analog converter(222), and a test voltage outputting unit(260). The voltage generator generates a common voltage and a gamma driving voltage. The gamma voltage generator generates plural gamma voltages using the gamma driving voltage. The digital/analog converter converts input test gray scale data into gray scale voltages using the gamma voltages and outputs the converted gray scale voltages. The test voltage outputting unit outputs voltage difference of the gray scale voltage on the common voltage as a test voltage.

Description

A driving device of a display device and a gamma setting device including the same. {DRIVING APPARATUS FOR DISPLAY DEVICE AND APPARATUS FOR SETTING GAMMA INCLUDING THE SAME}

1 is a view briefly illustrating a display device according to an exemplary embodiment of the present invention.

FIG. 2 is a detailed block diagram of the driving unit shown in FIG. 1.

3 is a view briefly illustrating a gamma voltage generator shown in FIG. 2.

4A to 4C are diagrams for schematically describing a gray voltage according to the adjustment of the gamma adjusting unit illustrated in FIG. 3.

5 is a diagram for describing a gamma setting apparatus of a display device according to an exemplary embodiment of the present invention.

6 is a measurement graph of a test voltage according to an embodiment of the present invention.

7 is a measurement graph of a test voltage according to another embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100: display device 110: display panel

112: array substrate 114: opposing substrate

152: gate driver 154: flexible circuit board

200: drive part TP: test pin

DA: display area PA1, PA2: peripheral area

TFT: thin film transistor CLC: liquid crystal capacitor

CST: Storage Capacitors GL1 to GLn: Gate Wirings

DL1 to DLm: source wirings

The present invention relates to a driving device of a display device and a gamma setting device including the same, and more particularly, to a driving device of a display device for simplifying a gamma voltage setting process and a gamma setting device including the same.

In general, gamma is a slope of the luminance characteristic curve and a deviation of the luminance value according to the voltage level output from the output terminal of the source driver.

When the LCD panel normally adopts a black mode (NB), the higher the voltage output from the source driver, the closer the screen is to white, and the lower the output voltage, the closer the image to black. In this case, a plurality of gray level values are output from the source driver between the white voltage and the black voltage. The output value is a voltage output value for each step is determined by the internal resistor and the resistance component of the source driver.

Such a voltage value according to each gray scale requires an accurate setting, and the voltage should be set to be a 2.2 gamma curve having the most desirable luminance characteristic recognized by the human eye. To this end, one gray level is displayed on the liquid crystal display panel and the luminance thereof is measured, and then the voltage is set by changing the variable resistance in the source driver by determining whether the gray gamma curve is satisfied. Since this method requires a continuous luminance measurement process until a voltage corresponding to each gray level is set, it takes a long time to set a gamma voltage for all gray levels.

Accordingly, the technical problem of the present invention is to solve such a conventional problem, and an object of the present invention is to provide a driving device of a display device which can simplify the gamma voltage setting process of the display device.

Another object of the present invention is to provide a gamma setting device that can simplify the gamma voltage setting step of the display device.

A driving apparatus of a display device according to an embodiment for realizing the object of the present invention includes a voltage generator, a gamma voltage generator, a digital / analog converter and a test voltage output. The voltage generator generates a common voltage and a gamma driving voltage, and the gamma voltage generator generates a plurality of gamma voltages using the gamma driving voltage. The digital / analog converter converts the input test grayscale data into a corresponding grayscale voltage using the gamma voltages and outputs the grayscale voltage. The test voltage output unit outputs a voltage difference of the gray voltage to the common voltage as a test voltage.

A gamma setting device according to an embodiment for realizing another object of the present invention includes a source driving circuit, a test voltage measuring unit, and a gamma adjustment calculating unit. The source driving circuit may include a gamma voltage generator configured to generate a plurality of gamma voltages using a gamma driving voltage, and a digital / analog converter configured to convert input test grayscale data into corresponding grayscale voltages using the gamma voltages. And a test voltage output unit configured to output a voltage difference between the common voltage and the gray voltage as a test voltage. The test voltage measuring unit measures the test voltage and outputs a measured value. The gamma adjustment calculating unit receives the measured value and calculates an error with a preset reference value to calculate an adjustment value of the gamma voltage generation unit.

According to such a driving device of a display device and a gamma setting device including the same, the gamma voltage of the display device can be measured by adjusting the voltage applied to the liquid crystal without using the brightness of the display panel when setting the gamma voltage of the display device. The setting process can be simplified, saving work time.

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

1 is a view briefly illustrating a display device according to an exemplary embodiment of the present invention.

Referring to FIG. 1, a display device according to an exemplary embodiment of the present invention includes a display panel 100 displaying an image, a driver 200, a gate driver 152, and a flexible circuit board 1544.

The display panel 100 includes an array substrate 110 and an opposing substrate 120 coupled to each other and a liquid crystal layer (not shown) interposed between the array substrate 110 and the opposing substrate 120. The display panel 100 is divided into a display area DA in which an image is displayed and peripheral areas PA1 and PA2 surrounding the display area DA.

In the display area DA, a plurality of gate lines GL1 to GLn extend in parallel in one direction, and a plurality of source lines DL1 to DLm intersect the gate lines GL1 to GLn. The plurality of pixel portions are formed to extend in parallel and are formed by the gate lines GL1 to GLn and the source lines DL1 to DLm. Where n and m are natural numbers. Each pixel portion includes a thin film transistor TFT in which a gate electrode and a source electrode are electrically connected to a gate line GL and a data line DL, respectively, and a liquid crystal electrically connected to a drain electrode of the thin film transistor TFT. The capacitor CLC and the storage capacitor CST are formed.

The gate driver 152 is formed in the second peripheral area PA2 positioned at one end of the gate lines GL1 to GLn and based on the gate control signal provided from the driver 200. The gate signals composed of a combination of the gate on signal and the gate off signal are sequentially output to the fields GL1 to GLn.

One end of the flexible circuit board 154 is attached to the first peripheral area PA1 of the display panel 100 to electrically connect an external device to the driving unit 200.

The driving unit 200 is formed of a single chip, and is mounted in the first peripheral area PA1 positioned at one end of the data lines DL1 to DLm to be the source lines DL1 to DLm. A gray voltage is output and a gate control signal is provided to the gate driver 152. In addition, a test pin TP to which a test voltage VT to be described below is output is included, and a pad may be formed at an end of the test pin TP for ease of measurement. The driving unit 200 will be described in more detail with reference to FIG. 2.

FIG. 2 is a detailed block diagram of the driving unit shown in FIG. 1.

1 and 2, the driver 200 includes a controller 210, a data driver 220, a gate controller 230, a voltage generator 240, a gamma voltage generator 250, and a test voltage output. The unit 260 is included.

The controller 210 receives from the external device the raw gradation data TDATA and the synchronization signals CONT for controlling the display thereof. The sync signals CONT include a vertical sync signal VSYNC representing a time required to display one frame, a horizontal sync signal HSYNC representing a time required to display one horizontal line, and data are supplied to the pixel unit. The data enable signal DE indicating the time required and the main clock signal MCLK for reference of the timing are included.

The controller 210 may include test grayscale data 210a in which the test raw grayscale data TDATA is processed for the display panel 100, and a source control signal corresponding to the test grayscale data 210a. 210b) is provided to the data driver 220. The source control signal 210b includes a horizontal start signal STH indicating the start of one horizontal line, a load signal TP indicating data output for one horizontal line, and a data clock signal DCLK for timing reference. Include.

In addition, the controller 210 generates a gate control signal 210c and a voltage control signal 210d and provides them to the gate controller 230 and the voltage generator 240, respectively. Here, the gate control signal 210c may be configured to indicate the start of the output of the gate signal to the first clock signal CLK1 and the second clock signal CLK2 and the gate lines GL1 to GLn, which are out of phase with each other. It includes a vertical start signal (STV).

The voltage generator 250 generates a gamma driving voltage GVDD, a gate driving voltage Voff, and a common voltage Vcom by using an external power source, respectively, so that the gamma voltage generator 250 and the gate controller 230 are used. The common voltage Vcom is also provided to the display panel 100 and to the test voltage output unit 260. Here, the common voltage Vcom is polarized inverted to a first level and a second level at a predetermined period (for example, one horizontal line period). For example, the common voltage Vcom is polarized inverted to 3.85 [V] defined as positive polarity (+) and −1.82 [V] defined as negative polarity (−).

The gamma voltage generator 250 generates a plurality of gamma voltages VREF by dividing the provided gamma driving voltage GVDD and the ground voltage, and provides the gamma voltages VREF to the data driver 220. The gamma voltage generator 250 may include negative gamma voltages VREF at a level lower than the positive common voltage Vcom, and the negative common voltage Vcom. Gamma voltages VREF of two voltage groups including gamma voltages VREF for positive polarity (+) of higher level are generated and provided to the data driver 220.

The data driver 220 includes a digital / analog converter 222, and converts the test grayscale data 210a into a corresponding gamma voltage and outputs the corresponding gamma voltages to the corresponding source lines DL1 to DLm. That is, when the test grayscale data 210a is provided in a timing according to the source control signal 210b, the grayscale data 210a is provided using the gamma voltages VREF provided by the gamma voltage generator 250 to correspond to the grayscale data VREF. The voltage is converted to a voltage and output to the source lines DL1 to DLm. Here, the gray voltage corresponds to the polarity of the common voltage Vcom using the positive gamma voltages VREF and the negative gamma voltages VREF (eg, the opposite polarity). Output the gray scale voltage. That is, when the common voltage Vcom is positive (+), the gray level voltage having a level lower than the common voltage Vcom is output using the negative gamma voltages VREF, and the common When the voltage Vcom is negative, the gray level voltage higher than the common voltage Vcom is output using the positive gamma voltages VREF. The polarity control of the gray voltage is performed by alternating gamma voltages VREF for positive and negative polarities corresponding to the polarity of the common voltage Vcom in the gamma voltage generator 250. The digital / analog converter 222 may be selectively provided by being included in the source control signal 210b and receiving the polarity inversion signal RVS.

The gate controller 230 provides the gate control signal 210c provided from the controller 210 and the gate driving voltage Voff provided from the voltage generator 240 to the gate driver 152.

The test voltage output unit 260 receives the common voltage Vcom from the voltage generator 240, receives the gray voltage output from the digital / analog converter 222, and receives the common voltage (VCOM). The voltage difference of the gray scale voltage with respect to Vcom is output to the test pin TP as a test voltage VT. For example, the test voltage output unit 260 receives the gray voltage output from the digital / analog converter unit 222 to the first source wiring DL1 to generate the test voltage VT.

3 is a diagram briefly illustrating a gamma voltage generation unit illustrated in FIG. 2, and FIGS. 4A to 4C are diagrams for schematically describing a gray voltage according to an adjustment of the gamma adjustment unit illustrated in FIG. 3.

Referring to FIG. 3, the gamma voltage generator 250 includes a gamma adjuster 252, a gamma reference voltage generator 254, a gamma reference voltage selector 256, and a gamma voltage output unit 258.

Here, the gamma reference voltage generator 254 and the gamma reference may be used to generate the gamma voltages VREF from two voltage groups, that is, the gamma voltages VREF of positive (+) and negative (−) values. The voltage selection unit 256 and the gamma voltage output unit 258 are each composed of two copies, but since the two configurations are the same, only one configuration is illustrated for simplicity and convenience of description.

The gamma adjusting unit 252 includes a tilt adjusting unit 252a, an amplitude adjusting unit 252b, and a fine adjusting unit 252c. Provided at 256.

The tilt adjusting unit 252a outputs second register values to the gamma reference voltage generator 254 for gradient adjustment of the gray level voltage to the gray number. Accordingly, the slopes of the gradation voltages of the plurality of gamma voltages VGH0 to VGH255 output through the gamma voltage output unit 258 are changed as shown in FIG. 3A.

The amplitude adjusting unit 252b outputs first register values for amplitude adjustment of the gray voltage to the gamma reference voltage generator 254. Accordingly, the amplitudes of the gradation voltages of the plurality of gamma voltages VGH0 to VGH255 output through the gamma voltage output unit 258 are changed as shown in FIG. 3B.

The fine adjusting unit 252c outputs third register values for fine adjustment of the gray voltage to the gamma reference voltage selecting unit 256. The gamma voltages VGH0 to VGH255 output through the gamma voltage output unit 258 are changed in gray level voltage as shown in FIG. 3C.

The gamma reference voltage generator 254 includes a resistor string in which a plurality of resistors are serially connected between the gamma driving voltage GVDD and the ground voltage VGS.

The resistor string generates gamma reference voltages for each level through voltage distribution of the resistors based on the gamma driving voltage GVDD and the ground voltage VGS to generate the gamma reference voltage selector 256 and the gamma voltage output unit. Output to (258).

The resistor string includes two first variable resistors 254a, a plurality of second variable resistors 254b, and fixed resistors 254c connected between the second variable resistors 254b. The first variable resistors 254a are disposed at both ends of the resistor string, and the resistance value is adjusted in response to the first resistor value provided by the amplitude adjusting unit 252b. The second variable resistors 254b are adjusted in response to a second resistor value provided from the tilt adjuster 252a. The fixed resistors 254c are connected between the second variable resistors 254b and have a fixed resistance value.

The gamma reference voltage selector 256 includes a plurality of selectors 256a, each selector 256a in response to a third register value provided by the fine adjustment unit 252c. One of sixteen or eight gamma reference voltages provided at 254 is selected and provided to the gamma voltage output unit 258. That is, the gamma reference voltage selector 256 provides the gamma voltage output units 258 with gamma reference voltages VR1 to VR5 corresponding to the number of the selectors 256a.

The gamma voltage output unit 258 may include two gamma reference voltages VR0 and VR6 provided by the gamma reference voltage generator 254 and selectors 256a of the gamma reference voltage selector 256. A plurality of gamma voltages VGH0 to VGH255 are generated using the plurality of gamma reference voltages VR1 to VR5, respectively, and output to the digital / analog converter 222.

Hereinafter, the gamma setting device including the driving device of the display device according to the embodiment of the present invention as described above will be described.

5 is a diagram for describing a gamma setting apparatus of a display device according to an exemplary embodiment of the present invention.

2 and 5, the gamma setting apparatus 600 for setting gamma of the display device 610 includes a digital / analog converter 222, a test voltage output unit 260, and a test voltage measuring unit 620. And a gamma adjustment calculator 630.

The digital / analog converter 612 is formed integrally with the driver 200 defined as a source driving circuit of the display device 600, and the driver 200 receives the test source gray scale data TDATA from an external device. After receiving and processing the data, the test grayscale data 210a is converted into a corresponding grayscale voltage and outputs the converted grayscale voltage.

개의 계조를 포함하며, 상기 표시 패널(100)에 상기 게이트 배선들(GL1 ~ GLn)이 연장되는 방향으로 블랙에서 화이트로 단계적으로 표시되거나, 화이트에서 블랙으로 단계적으로 표시되도록 계조를 구성하는 것이 바람직하다. 즉, 1프레임 구간에

개의 계조가 순차적으로 표시되도록 계조 데이터를 구성하는 것이 바람직하다. 여기서, k는 자연수이다.The test gray scale data 210a may be expressed by the digital / analog converter 222.

And gray scales, wherein the gray scales are displayed in steps of black to white in the direction in which the gate lines GL1 to GLn extend on the display panel 100, or are configured to display in steps of white to black. Do. That is, in one frame section

It is preferable to configure the gray scale data so that the two gray scales are displayed sequentially. Where k is a natural number.

The test voltage output unit 260 outputs a test voltage VT through the test pin TP. The test voltage VT is a voltage difference of the gray voltage with respect to the common voltage Vcom, and a different value is different when the common voltage Vcom is positive and negative. Is output.

개의 계조가 순차적으로 표시되도록 구성한 경우에, 1수직주기 동안의 시간변화가 계조 변화에 대응하 므로 상기 테스트 전압 측정부(620)는 시간에 대한 전압을 출력할 수 있는 오실로스코프(oscilloscope)를 활용할 수 있다.The test voltage measuring unit 620 measures a test voltage output from the test voltage output unit 260 through the test pin TP, and calculates the gamma adjustment of the measured value of the measured test voltage VT. Performs a function provided to the unit 630. For example, the test grayscale data 210a may be stored in one frame section.

In the case where the two gray scales are configured to be displayed sequentially, the test voltage measuring unit 620 may use an oscilloscope capable of outputting a voltage over time since the time change during one vertical period corresponds to the gray change. have.

The gamma adjustment calculator 630 receives a measurement value of the test voltage VT corresponding to the test grayscale data 210a from the test voltage measurer 620. An error with a preset reference value is calculated to calculate an adjustment value of the gamma voltage generator 250 to set the optimum gamma voltage. For example, the adjustment values are register values output from the gamma adjustment unit 252.

개의 모든 계조에 대한 감마전압 설정을 동시에 수행할 수 있으므로, 최적의 감마전압을 설정하기 위한 조정 회수를 현저히 줄일 수 있게 되어 감마 설정공정이 간략화 된다.As described above, the gamma setting apparatus 600 according to the exemplary embodiment of the present invention measures the test voltage VT output from the source driving circuit through the test pin TP, and based on this, the optimum gamma voltages ( The adjustment value for setting VREF) is calculated. The gamma voltage is set by an operator (for example, a producer) adjusting the register values of the gamma voltage generator 250 according to the calculated adjustment value. Therefore, the gamma setting is not repeated for each gray scale independently,

Since the gamma voltage setting for all the gray levels can be performed at the same time, the number of adjustments for setting the optimum gamma voltage can be significantly reduced, thereby simplifying the gamma setting process.

Hereinafter, an embodiment according to the output method of the test voltage output unit 260 will be described.

6 is a measurement graph of a test voltage according to an embodiment of the present invention.

5 and 6, the graph of the test voltage VT is a case in which the test voltage output unit 260 outputs the test voltage VT based on the common voltage Vcom. . That is, the test voltage VT is output by subtracting the voltage value of the gray voltage from the voltage value of the common voltage Vcom.

Specifically, when the common voltage Vcom is positive polarity, the gray voltage is output at a level lower than the common voltage Vcom, so that the test voltage VT is output as a positive value. do. On the other hand, when the common voltage Vcom is negative, the gray scale voltage is output at a level higher than the common voltage Vcom, so that the test voltage VT is output as a negative value. do.

As described above, when the output test voltage VT is divided into a positive value and a negative value and is output, it is not easy to compare the two values. Suggest a way.

7 is a measurement graph of a test voltage according to another embodiment of the present invention.

5 and 7, the graph of the test voltage VT is illustrated in the test voltage output unit 260 when the polarity of the common voltage Vcom is negative. ) Is inverted and output.

Specifically, when the common voltage Vcom is positive polarity, the gray voltage is output at a level lower than the common voltage Vcom, so that the gray voltage of the gray voltage with respect to the voltage value of the common voltage Vcom is output. The test voltage VT, which is a voltage difference, is output as a positive value.

When the common voltage Vcom is negative, the gray voltage is output at a level higher than the common voltage Vcom, and thus is a voltage difference of the gray voltage to the voltage value of the common voltage Vcom. The test voltage VT becomes a negative value, but by inverting and outputting the test voltage VT, the test voltage VT has a positive value when the common voltage Vcom is negative. Is output. That is, in both cases, the test voltage VT having a positive value is output regardless of the polarity of the common voltage Vcom.

As such, by outputting the test voltage VT only with a positive value, it is easier to compare the test voltage VT with respect to the polarity of the common voltage Vcom, and thus the display panel 100 is generated. By setting the gamma voltage in consideration of the kickback voltage, it is very easy to improve defects such as flicker caused by the kickback voltage.

As described above, according to the present invention, the gamma voltage is measured based on the voltage difference between the common voltage and the gray voltage, which are voltages applied to the liquid crystal, without using the luminance of the display panel when setting the gamma voltage of the display device. By setting this, the gamma voltage setting process can be simplified and the working time can be saved. In addition, by setting the gamma voltage in consideration of the kickback voltage of the display panel by comparing the gamma voltage according to the polarity inversion of the common voltage, the gamma voltage may be set so as to improve a defect such as flicker caused by the kickback voltage.

Although described above with reference to the embodiments, those skilled in the art can be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below. I can understand.

Claims (8)

A voltage generator configured to generate a common voltage and a gamma driving voltage; A gamma voltage generator configured to generate a plurality of gamma voltages using the gamma driving voltage; A digital / analog converter configured to convert input test grayscale data into corresponding grayscale voltages using the gamma voltages and output the converted grayscale data; And And a test voltage output unit configured to output a voltage difference of the gray voltage to the common voltage as a test voltage. The method of claim 1, wherein the digital to analog converter unit

Can be represented, and the test grayscale data is

A driving device (k is a natural number) of a display device, characterized in that it comprises four gray levels. The method of claim 2, wherein the common voltage is polarized inverted at a predetermined period. The digital / analog converter outputs a gray level voltage lower than the common voltage when the common voltage is positive, and outputs a gray level voltage higher than the common voltage when the common voltage is negative. A drive device for a display device. 4. The driving apparatus of claim 3, wherein the test voltage output unit inverts the voltage difference between the gray voltages with respect to the common voltage and outputs the test voltage as the test voltage when the common voltage is negative. 5. A gamma voltage generator for generating a plurality of gamma voltages using a gamma driving voltage, a digital / analog converter for converting the input gray level data into a corresponding gray voltage using the gamma voltages, and outputting the same; A source driving circuit including a test voltage output unit configured to output a voltage difference between the gray scale voltages as a test voltage; A test voltage measuring unit measuring the test voltage and outputting a measured value; And And a gamma adjustment calculating unit configured to receive the measured value and calculate an error from a preset reference value to calculate an adjustment value of the gamma voltage generator. The method of claim 5, wherein the digital to analog converter unit

Can be represented, and the test grayscale data is

A gamma setting device (k is a natural number), characterized in that it comprises four gray levels. The method of claim 6, wherein the common voltage is polarized inverted at a predetermined period. The digital / analog converter outputs a gray level voltage lower than the common voltage when the common voltage is positive, and outputs a gray level voltage higher than the common voltage when the common voltage is negative. Gamma setting device. The gamma setting device of claim 7, wherein the test voltage output unit inverts the voltage difference of the gray voltage with respect to the common voltage when the common voltage is negative to output the test voltage as the test voltage.

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