KR20060127425A - Display device and method driving of the same - Google Patents

Abstract

A display device and a driving method thereof are provided to improve the luminance characteristic of the display device by making the brightness of a screen uniform in a normal driving mode and an impulsive driving mode by applying a gamma curve brighter than a gamma curve applied to the normal driving mode, in the impulsive driving mode. A display device includes a display panel(170) displaying an image; a reference gamma voltage generating unit(140) generating and outputting first and second reference gamma voltages corresponding to a normal driving mode and an impulsive driving mode, respectively; a timing control unit(110) determining the normal driving mode and the impulsive driving mode by an input mode selection signal and controlling the reference gamma voltage generating unit correspondingly to the determined driving mode; and a data driving unit(150) converting the input data signal into an analog-type data voltage by using the reference gamma voltage and then outputting the analog-type data voltage to the display panel.

Description

Display device and driving method thereof {DISPLAY DEVICE AND METHOD DRIVING OF THE SAME}

1 is a schematic block diagram of a display device according to an exemplary embodiment of the present invention.

FIG. 2 is a detailed block diagram of the timing controller shown in FIG. 1.

FIG. 3 is a detailed block diagram illustrating the reference gamma voltage generator shown in FIG. 1.

4 is a flowchart for describing a method of driving the display device illustrated in FIG. 1.

5 is a graph illustrating first and second gamma curves driven by the reference gamma voltage generator.

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

110: timing controller 120: storage unit

130: driving voltage generator 140: reference gamma voltage generator

150: data driver 160: gate driver

170: display panel

The present invention relates to a display device and a driving device thereof, and more particularly, to a display device and a driving method thereof for improving the luminance characteristic of a display screen.

In general, a cathode ray tube (CRT) displays an image signal in an impulse manner, while a liquid crystal display displays an image signal in a hold manner. As a result, a liquid crystal display device is vulnerable to moving images due to the drag of the screen due to the slow response time when the video is implemented.

In order to eliminate the screen drag, a black data insertion method is used in which black data is inserted for a certain period of time in one frame period.

However, the black data insertion method visually improves the moving image quality by removing the drag phenomenon, but has a disadvantage in that the brightness of the screen decreases as the black data is inserted.

Therefore, as the brightness of the screen by the black insertion method is significantly lower than the brightness of the screen by the normal driving method, the visual luminance characteristic of the liquid crystal display device is lowered.

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 display device for visually and uniformly adjusting the brightness of the screen by the normal driving method and the brightness of the screen by the black insertion method. To provide.

Another object of the present invention is to provide a method of driving the display device.

A display device according to an embodiment for realizing the above object of the present invention includes a display panel, a reference gamma voltage generator, a timing controller, and a data driver. The display panel displays an image. The reference gamma voltage generator generates and outputs first reference gamma voltages and second reference gamma voltages corresponding to the normal driving mode and the impulsive driving mode, respectively. The timing controller determines the first and impulsive driving modes using the input mode selection signal, and controls the reference gamma voltage generator in response to the determined driving mode. The data driver converts an input data signal using the reference gamma voltages into an analog data voltage and outputs the data signal to the display panel.

The reference gamma voltage generation unit includes a plurality of resistors for distributing a plurality of reference gamma voltages based on a power supply voltage, an adjustment resistor connected to a resistor connected to a terminal of the power supply voltage, and connected to both ends of the adjustment resistor. It includes a switch for controlling whether the bypass.

When the mode selection signal is the normal driving mode, the timing controller turns off the switch so as to include a first reference reference voltage having a highest level of reference gamma voltage distributed by a resistor connected to a terminal of the power supply voltage and a control resistor. Output gamma voltages.

When the mode selection signal is the impulsive driving mode, the timing controller turns on the switch to include a second reference gamma voltage including a reference gamma voltage of the highest level distributed by a resistor connected to the terminal of the power supply voltage. Output them.

The first reference gamma voltages are substantially greater than the second reference gamma voltages.

Preferably, the normal driving mode converts the input data signal into an analog data voltage and outputs the data signal to the display panel. The impulsive driving mode converts the input data signal and the low gray level data signal into an analog data voltage. Each of them is converted to output data voltages corresponding to the data signals and data voltages corresponding to the low gradation data signals to the display panel at a predetermined ratio.

A plurality of resistors for distributing a plurality of reference gamma voltages based on a power supply voltage, an adjustment resistor connected to a resistor connected to a terminal of the power supply voltage, and the adjustment according to another embodiment of the present invention. A driving method of a display device including a reference gamma voltage generator including a switch connected to both ends of a resistor to control whether the regulating resistor is bypassed may include: (a) normal driving mode and impulsive driving using an input mode selection signal; Determining a mode; (b) outputting first reference gamma voltages and second reference gamma voltages corresponding to the normal driving mode and the impulsive driving mode according to the determination result; and (c) outputting the reference. Converting the input data signal based on the gamma voltage into an analog data voltage and outputting the data signal to the display panel.

According to the display device and the driving method thereof, the brightness of the screen may be uniform regardless of the driving mode by applying a gamma curve that is relatively brighter than the gamma curve applied to the normal driving mode in the impulsive driving mode.

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

1 is a schematic block diagram of a display device according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the display device includes a timing controller 110, a storage 120, a driving voltage generator 130, a reference gamma voltage generator 140, a data driver 150, and a gate driver 160. And a display panel 170.

The timing controller 110 generates and outputs first to third control signals 110a, 110c, and 110e based on the control signal 101 input from an external device.

The first control signal 110a is provided to the driving voltage generator 130, the second control signal 110c is provided to the data driver 150, and the third control signal 110e is The gate driver 160 is provided to control each drive.

The timing controller 110 transmits the data signal 102 input from the external device to the data driver 150.

The timing controller 110 outputs a fourth control signal 110d for controlling the reference gamma voltage generator 140 based on the mode selection signal 103 input from the external device.

The data unit 120 stores the data signal in a predetermined unit. Preferably, the data is stored in a field unit and a frame unit. The timing controller 120 controls to record or read the data signal to the storage 120.

The driving voltage generator 130 generates driving voltages for driving the display device. Specifically, the power supply voltage (VDD) 130a is output to the reference gamma voltage generator 140, the gate voltages 130b are output to the gate driver 160, and the display panel 170 is common. Output voltages 130c.

 The reference gamma voltage generator 140 divides and outputs the power supply voltage VDD provided from the driving voltage generator 130 into a plurality of reference gamma voltages through a resistor string in which a plurality of resistors are connected in series. The reference gamma voltage generator 140 may generate a second reference gamma voltage or a second gamma curve corresponding to a first gamma curve based on the fourth control signal 110b of the timing controller 110. Output the reference gamma voltages.

Specifically, the reference gamma voltage generator 130 outputs first reference gamma voltages corresponding to the first gamma curve when the mode selection signal 103 provided from an external device is in a normal driving mode, and selects the mode. When the signal 103 is in the impulsive driving mode, second reference gamma voltages corresponding to the second gamma curve are output. The first gamma curve is a dark gamma curve compared to the second gamma curve.

The data driver 150 converts the input data signal 110d into an analog data voltage using the reference gamma voltages 140a and outputs the converted data voltage to the display panel 660.

In detail, when the mode selection signal 103 is in the normal driving mode, the data signal 110d is converted into an analog data voltage based on the first reference gamma voltages provided from the reference gamma voltage generator 140. Convert and output

Meanwhile, when the mode selection signal 103 is in the impulsive driving mode, the data signal 110d is converted into an analog data voltage based on the second reference gamma voltages provided from the reference gamma voltage generator 140. Convert and output

Preferably, in the normal driving mode, the data driver 150 outputs an analog data voltage according to the second control signal 110c based on the first driving frequency. In the impulsive driving mode, the data driving unit 150 outputs an analog data voltage. The data driver 150 outputs an analog data voltage by the second control signal 110c based on the second driving frequency multiplied by twice the driving frequency.

Specifically, in the normal driving mode, the data driver 150 converts the provided normal data signal 110d into an analog data voltage and outputs the converted data voltage to the display panel 170. . That is, the normal image is displayed on the display panel 170.

In the impulsive driving mode, the data driver 150 outputs a data voltage corresponding to a normal data signal to the display panel 170 in a first section of one frame section, and outputs a second data voltage to the display panel 170. In the section, an impulsive data voltage corresponding to a low or high gray data signal than the normal data signal is output to the display panel 170. Therefore, a normal image is displayed in a first section of one frame section, and an impulsive image is displayed in a second section. Here, the ratio of the first section in which the normal image is displayed and the second section in which the impulsive image is displayed is (1: 1), (1: 2), (1: 3), (2: 1), (3 1) It can be applied in various ways.

The gate driver 160 generates gate signals using the third control signal provided from the timing controller 110 and the gate voltages 130b provided from the driving voltage generator 130, and generates the generated gate signals. The display is output to the display panel 170.

The display panel 170 has an array substrate, an upper substrate, and a liquid crystal layer interposed between the substrates. The display panel 170 has a plurality of data lines DL and a plurality of gate lines GL crossing the data lines DL, and the plurality of data lines DL is defined by the data lines and the gate lines. The pixel portions P are provided. In the pixel portion P, a switching element TFT, a liquid crystal capacitor CLC, and a storage capacitor CST are formed. Common voltages VCOM and VSCT generated from the driving voltage generator 130 are applied to the common electrode of the liquid crystal capacitor CLC and the storage capacitor CST.

FIG. 2 is a detailed block diagram of the timing controller shown in FIG. 1.

Referring to FIG. 2, the timing controller 110 includes a controller 111 and a control signal generator 113.

The controller 111 records the input data signal 102 in the storage 120 and reads the recorded data signal 102 into the data driver 150.

The controller 111 controls the control signal generator 113 in response to the input mode selection signal 103. Accordingly, the control signal generator 113 generates first to third control signals 110a, 110c, and 110e corresponding to the first driving frequency when the mode selection signal 103 is in the normal driving mode. When the mode selection signal 103 is an impulsive driving mode, the control signal generator 113 may include first to third control signals corresponding to a second driving frequency doubled with respect to the first driving frequency. Produce (110a, 110c, 110e).

The first control signal 110a is provided to the driving voltage generator 130, the second control signal 110c is provided to the data driver 150, and the third control signal 110e is The gate driver 160 is provided.

The control signal 101 includes a main clock signal MCLK, a horizontal synchronization signal HSYNC, a vertical synchronization signal VSYNC, and a data enable signal DE. The first control signal 110a includes a main clock signal MCLK, the second control signal 110c includes a horizontal start signal STH and a load signal TP, and the third control signal 110e includes a start signal STV, a scan clock signal CPV, and an output enable signal OE.

The controller 111 outputs the fourth control signal 110b based on the mode selection signal 103. The fourth control signal 110b is a signal for controlling the reference gamma voltage generator 140, and the reference gamma voltage generator 140 is a first gamma in the normal driving mode based on the fourth control signal. First reference gamma voltages corresponding to the curve γ1 are output, and second reference gamma voltages corresponding to the second gamma curve γ1 are output in the impulsive driving mode.

Here, the first gamma curve γ1 is a gamma curve having a higher luminance than the second gamma curve γ1.

FIG. 3 is a detailed block diagram illustrating the reference gamma voltage generator shown in FIG. 1.

1 and 3, the reference gamma voltage generator includes a switching unit 131 and a distribution resistor unit 135.

The switching unit 131 includes a first switch SW1 and a second switch SW2 for switching based on the fourth control signal 110b provided from the timing controller 110.

The first switch SW1 determines the reference gamma voltage Vg1 of the negative highest level as one of the first level Vg1-1 and the second level Vg1-2.

The second switch SW2 determines the reference gamma voltage Vg16 of the highest bipolar level as one of the first level Vg16-1 and the second level Vg16-2.

The distribution resistor unit 135 includes 17 resistors R1 to R17 for outputting 16 reference gamma voltages Vg1 to Vg16, and includes a first regulating resistor connected to the first switch SW1. R1-1) and a second control resistor R1-2 connected to the second switch SW2. The first and second regulating resistors R1-1 and R17-1 may use a fixed resistor or a variable resistor.

The upper eight reference gamma voltages Vg9 to Vg16 of the sixteen reference gamma voltages Vg1 to Vg16 are bipolar voltages relative to the reference voltage, and the lower eight reference gamma voltages Vg1 to Vg8 are negative to the reference voltage. Polarity voltage.

The first switch SW1 is electrically connected to both ends of the first control resistor R1 ′ connected in series with the first resistor R1 connected to the ground terminal GND.

When the switch SW1 is turned off, the reference gamma voltage Vg1-1 having the first level divided by the first resistor R1 and the first regulating resistor R1 'is output. When the switch SW1 is turned on, the first control resistor R1 ′ is bypassed to output the reference gamma voltage Vg1-2 of the second level distributed by the first resistor R1.

The reference gamma voltage Vg1-1 or Vg1-2 is a reference gamma voltage of the highest level (eg, 255 gray) among the reference gamma voltages Vg1 to Vg8 of the negative polarity.

The second switch SW2 is electrically connected to both ends of the seventeenth control resistor R17 'connected in series with the seventeenth resistor R17 connected to the power voltage input terminal VDD.

When the switch SW2 is turned off, the reference gamma voltage Vg16-1 of the first level divided by the seventeenth resistor R17 and the seventeenth control resistor R17 ′ is output. When the switch SW2 is turned on, the seventeenth control resistor R17 'is bypassed to output the reference gamma voltage Vg16-2 of the second level distributed by the seventeenth resistor R17.

The reference gamma voltage Vg16-1 or Vg16-2 is a reference gamma voltage of the highest level (for example, 255 gray) among the bipolar reference gamma voltages Vg9 to Vg16.

Specifically, in the normal driving mode, the fourth control signal 110b turns off the switching unit 131, and thus the distribution resistor unit 135 adds the first and second adjustment resistors R1. -1, R17-1) is applied to output the reference gamma voltages.

The reference gamma voltage Vg1 of the bipolar highest level output from the distribution resistor unit 135 outputs the reference gamma voltage Vg1-1 increased by a predetermined level by the first control resistor R1-1, and is negative. The reference gamma voltage Vg16 having the highest polarity level outputs the reference gamma voltage Vg16-1 reduced to a predetermined level by the second control resistor R17-1.

The remaining reference gamma voltages Vg2-1 to Vg15-1 are based on the reference gamma voltage Vg16-1 of the highest positive polarity level and the reference gamma voltage Vg1-1 of the negative highest level. To R16) and output respectively.

 In the impulsive driving mode, the fourth control signal 110b turns on the switching unit 131. Accordingly, the distribution resistor unit 135 adds the first and second regulating resistors R11-. 1, R17-1) outputs bypassed reference gamma voltages.

The reference gamma voltage Vg1 of the negative highest level output from the distribution resistor unit 135 outputs the second reference gamma voltage Vg1-2 in which the first control resistor R1-1 is bypassed. The reference gamma voltage Vg16 having the highest bipolar level outputs the second reference gamma voltage Vg16-2 through which the second control resistor R17-1 is bypassed.

The remaining reference gamma voltages Vg2-2 to Vg15-2 are based on the reference gamma voltage Vg16-2 of the highest bipolar level and the reference gamma voltage Vg1-2 of the negative highest level. To R16) and output respectively.

Accordingly, the first reference gamma voltages Vg1-1 to Vg16-1 corresponding to the first gamma curve γ1 are output in the normal driving mode, and the second gamma curve γ2 corresponding to the second gamma curve γ2 in the impulsive driving mode. Second reference gamma voltages Vg1-2 to Vg16-2 are output.

In the above, the case where the display panel 170 operates in the normally black mode has been described as an example. When the display panel 170 operates in the normally white mode, the reference gamma voltages Vg1 and Vg16 at the highest level are close to zero, and the reference gamma voltages Vg8 and Vg9 at the lowest level are at a predetermined level. Voltage.

4 is a flowchart for describing a method of driving the display device illustrated in FIG. 1. 5 is a graph illustrating first and second gamma curves driven by the reference gamma voltage generator.

1 to 5, a mode selection signal 103 for selecting a normal driving mode or an impulsive driving mode is input to the timing controller 110 (S210).

The timing controller 110 determines a driving mode currently selected from a normal driving mode or an impulsive driving mode based on the mode selection signal 103.

First, when the mode selection signal 103 is in the normal driving mode (S212), the timing controller 110 turns off the switching unit 141 of the reference gamma voltage generator 140. 110b is output to the reference gamma voltage generator 140.

The switching unit 141 is turned off by the fourth control signal 110b (S213).

As the switching unit 141 is turned off, the reference gamma voltage Vg1 of the negative highest level is distributed by the first resistor R1 and the first control resistor R1 ′, so that the reference gamma of the first level is reduced. Has a voltage Vg1-1. On the other hand, the reference gamma voltage Vg16 of the highest bipolar level is also divided by the seventeenth resistor R17 and the second control resistor R17 'to have the reference gamma voltage Vg16-1 of the first level.

As a result, the reference gamma voltage generation unit 140 outputs first reference gamma voltages Vg1-1 to Vg16-1 corresponding to the first gamma curve γ1 as shown in FIG. 5 (S214. ).

The data driver 150 converts the input data signal 110d into analog data voltages using the first reference gamma voltages Vg1-1 to Vg16-1 to the display panel 170. Output (S230).

On the other hand, when the mode selection signal 103 is in the impulsive driving mode (S222), the timing controller 110 controls the fourth control to turn on the switching unit 141 of the reference gamma voltage generator 140 The signal 110b is output to the reference gamma voltage generator 140.

The switching unit 141 is turned off by the fourth control signal 110b (S213).

As the switching unit 141 is turned on, the reference gamma voltage Vg1 of the negative highest level is distributed by the first resistor R1 to have the reference gamma voltage Vg1-2 of the second level. On the other hand, the reference gamma voltage Vg16 of the highest bipolar level is also distributed by the seventeenth resistor R17 to have the reference gamma voltage Vg16-2 of the second level.

As a result, the reference gamma voltage generation unit 140 outputs second reference gamma voltages Vg1-2 to Vg16-2 corresponding to the second gamma curve γ 2, as shown in FIG. 5 (S214). ). Here, the second gamma curve γ 2 has a high luminance to the first gamma curve γ 1.

Thereafter, the data driver 150 converts the input data signal 110d into analog data voltages using the second reference gamma voltages Vg1-2 to Vg16-2 and converts the data signal 110d into an analog data voltage. And outputs it to 170 (S230).

As described above, according to the present invention, a gamma curve that is relatively brighter than the gamma curve applied to the normal driving mode is applied in the impulsive driving mode. As a result, the brightness of the display device can be improved by making the brightness of the screen uniform in the normal driving mode and the impulsive driving mode.

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 (13)

A display panel displaying an image; A reference gamma voltage generator configured to generate and output a first reference gamma voltage and a second reference gamma voltage respectively in response to a normal driving mode and an impulsive driving mode; A timing controller which determines the normal driving mode and the impulsive driving mode based on the input mode selection signal, and controls the reference gamma voltage generator in response to the determined driving mode; And And a data driver converting the data signal input using the reference gamma voltage into an analog data voltage and outputting the data signal to the display panel. The method of claim 1, wherein the reference gamma voltage generator A plurality of resistors for distributing a plurality of reference gamma voltages based on a power supply voltage; A control resistor connected to a resistor connected to the terminal of the power supply voltage; And a switch connected to both ends of the control resistor to control whether the control resistor is bypassed. The method of claim 2, wherein when the mode selection signal is the normal driving mode, And the timing controller turns off the switch and outputs first reference gamma voltages including a reference gamma voltage of a highest level distributed by a resistor connected to a terminal of the power supply voltage and an adjustment resistor. The method of claim 2, wherein when the mode selection signal is the impulsive driving mode, And the timing controller turns on the switch to output second reference gamma voltages including the reference gamma voltage of the highest level distributed by a resistor connected to the terminal of the power supply voltage. The display device of claim 2, wherein the first reference gamma voltages are lower than the second reference gamma voltages. The display device of claim 2, wherein the power supply voltage is a ground voltage. The display device of claim 6, wherein the first reference gamma voltages are higher than the second reference gamma voltages. The display device of claim 1, wherein the normal driving mode converts the input data signal into an analog data voltage and outputs the data voltage to the display panel. The method of claim 1, wherein the impulsive driving mode is Converting the input data signal and the low gradation data signal into analog data voltages respectively, and outputting the data voltage corresponding to the data signal and the data voltage corresponding to the low gradation data signal to the display panel at a predetermined ratio. Display device characterized in that. A plurality of resistors for distributing a plurality of reference gamma voltages based on a power supply voltage, a control resistor connected to a resistor connected to the terminal of the power supply voltage, and connected to both ends of the control resistor to control whether the control resistor is bypassed. In the driving method of the display device including a reference gamma voltage generation unit including a switch, (a) determining a normal driving mode and an impulsive driving mode using the input mode selection signal; (b) outputting first reference gamma voltages and second reference gamma voltages corresponding to the normal driving mode and the impulsive driving mode, respectively, according to the determination result; And and (c) converting the input data signal into an analog data voltage based on the output reference gamma voltage and outputting the data signal to the display panel. 11. The method of claim 10, wherein in the normal driving mode, the step (b) Turning off the switch; And And outputting first reference gamma voltages including a reference gamma voltage of a highest level distributed by a resistor connected to the terminal of the power supply voltage and a control resistor. 12. The method of claim 10, wherein in the impulsive driving mode, step (b) Turning on the switch; And And outputting second reference gamma voltages including a reference gamma voltage of the highest level distributed by a resistor connected to the terminal of the power supply voltage. The method of claim 10, wherein the power supply voltage is a ground voltage.

Images