KR20060119267A - Method of driving for display device and display device using the same - Google Patents

Abstract

A driving method of a display device and the display device using the same are provided to keep the power consumption rate low by driving a display panel with low current if the display device is driven by a portable power source and to display an image of high definition on the display panel by driving the display panel with high current if the display device is driven by an external power source. A driving method of a display device having a display panel includes the steps of judging whether the present mode is a driving mode using a portable power source or an external power source, on the basis of an input mode signal(S100,S110); and driving the display panel with current relatively higher than that of the driving mode using the portable power source, if the present driving mode uses the external power source(S130).

Description

Method of driving a display device and a display device using the same {{FIELD OF DRIVING FOR DISPLAY DEVICE AND DISPLAY DEVICE USING THE SAME}

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

FIG. 2 is a detailed block diagram of a first embodiment of the gray level compensation unit of FIG. 1.

FIG. 3 is a detailed block diagram of a second embodiment of the gray level compensation unit of FIG. 1.

4 is a diagram for describing a method of driving a display device according to an exemplary embodiment.

Explanation of symbols on the main parts of the drawings

100: system unit 200: panel drive unit

210: timing controller 220: gray voltage generator

230: gradation compensation unit 240: power supply unit

300: display panel 310: display

320: data driver 330: gate driver

The present invention relates to a method of driving a display device and a display device using the same, and more particularly, to a method of driving a display device and a display device using the same, which can improve display quality of a portable display device.

Electronic devices such as mobile phones, personal digital assistants (PDAs), Pocket PCs, and Note PCs are developing around a common point of display devices. That is, the development from the early black-and-white display device to the color display device has been developed in recent years also in the sharpness of the display device.

In general, a display device having a flat plate shape is mainly used for the above electronic devices. One of such flat panel displays, a liquid crystal display (LCD), is an apparatus that displays an image using liquid crystal, and is thinner and lighter than other flat panel displays, and has a low driving voltage and low power consumption. It has advantages and is used extensively throughout the industry.

The electronic devices are driven in a driving mode using an external power source by connecting a driving mode using a portable power source such as a battery and a power cable due to the characteristics of a mobile device.

However, the driving modes are determined by the driving system of the mobile device, so that the liquid crystal display used in the mobile device is driven by the driving mode of the driving system. For example, when the driving system drives the power saving mode to reduce the current consumption of the portable power source, the liquid crystal display device also drives the power saving mode accordingly, such that an image is not displayed.

In addition, as the mobile devices have low power consumption, there is a problem in that, for example, a high picture quality implemented in a monitor or a TV cannot be obtained.

An object of the present invention for solving the above problems is to provide a method of driving a display device that can improve the display quality while reducing power consumption.

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

In order to achieve the above object, a display device driving method according to an exemplary embodiment of the present invention provides a method of driving a display device having a display panel, wherein a current driving mode is driven using a portable power source based on an input mode signal. Determining whether the driving mode is a mode or a driving mode using an external power source, and driving the display panel with a relatively high current consumption when compared to the driving mode using the portable power source.

In this case, the driving of the high current consumption may include converting an input data signal into a compensation data signal classified according to colors, and converting the compensation data signal into an analog data signal and outputting the converted data signal to the display panel. It may include the step.

The driving of the high current consumption may include outputting a compensation data signal corresponding to an input data signal and a data signal of a previous frame, and converting the compensation data signal into an analog data signal to the display panel. It may also include the step of outputting.

The driving of the high current consumption may include boosting and outputting an analog driving voltage and converting the compensation data signal into an analog data signal using the boosted analog driving voltage and outputting the analog data to the display panel. It may also include a step.

In order to achieve another object of the present invention, the display device according to an embodiment of the present invention includes a display panel, a timing controller, a gray level compensator, and a data driver. The display panel displays an image. The timing controller determines whether the current driving mode is a driving mode using a portable power source and a driving mode using an external power source through the input mode signal. In the driving mode using the external power source, the gray level compensator converts the input data signal into a compensation data signal and outputs the compensation data signal. The data driver converts the compensation data signal into an analog data signal and outputs the data signal to the display panel.

The gray level compensator outputs a corresponding R compensation data signal using a first lookup table to which the R compensation data signal corresponding to the input R data signal is mapped, and the G compensation corresponding to the input G data signal. The G gray level compensator outputs the corresponding G compensation data signal using the second lookup table to which the data signal is mapped, and the third lookup table to which the B compensation data signal corresponding to the input B data signal is mapped. And a B gray level compensator for outputting a B compensation data signal.

The gray level compensator may include a look up table configured to store a compensation data signal mapped to an input data signal and a data signal of a previous frame, and use the look up table to compensate data corresponding to the input data signal. Output the signal.

The display device further includes a power supply unit for boosting and outputting an analog driving voltage input to the data driver to a predetermined level.

According to such a driving method and a display device of the display device, when the portable power source is used, the display panel unit can be driven at a low power consumption to achieve low power consumption, and when the external power source is used, the display panel unit is driven with a high current consumption. As a result, display quality of high quality can be realized, and the display panel unit can be driven regardless of the state change of the driving system driving the display panel unit.

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

1 is a block diagram schematically 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 system unit 100, a panel driver 200, and a display panel unit 300.

The system unit 100 operates in one of a first driving mode using a portable power source and a second driving mode using an external power source, and transmits the first data signals R, G, and B to the panel driver 200. And control signals Vsync and Hsync for controlling the output of the first data signals R, G, and B, and mode signals SM1 and SM2 indicating the driving mode.

Here, the first driving mode means a driving mode using a portable power source written in the claims, and the second driving mode means a driving mode using an external power source written in the claims. Hereinafter, the terms of the first and second driving modes will be described.

The panel driver 200 includes a timing controller 210, a gray voltage generator 220, a gray compensator 230, and a power supply 240.

The timing controller 210 controls the overall operation of the display panel 300 and provides a clock signal CLK and a read enable signal RE to the gray level compensator 230. In addition, the timing controller 210 selectively applies the first data signals R, G, and B to the gray level compensation unit 210 or the display panel unit 300 according to the driving mode of the system unit 100. The output-controlled second data signals R ', G', B 'are output.

The gray voltage generator 220 uses the analog driving voltage AVDD provided from the power supply 240 as a reference voltage, and corresponds to the gray level corresponding to the number of gray levels based on a distribution resistor having a resistance ratio to which a gamma curve is applied. The voltage is distributed and output.

The gray level compensator 230 receives the second data signals R ′, G ′ and B ′ whose output timing is controlled by the timing controller 210, and compensates the third data compensated by a preset lookup table. The signals R ", G", and B "are outputted.

Here, the gray level compensation unit 230 will be described in detail with reference to FIGS. 2 and 3 as follows.

FIG. 2 is a detailed block diagram of a gradation compensator of FIG. 1 according to a first embodiment, and the gradation compensator 230 compensates for each of the input second data signals R ', G', and B '. An adaptive color correction (ACC) circuit for outputting the compensation data of each input color data by using a look-up table to which a signal is mapped.

2, the gray level compensator 230 according to the first embodiment of the present invention includes a memory unit 231 and a dithering unit 232.

The memory unit 231 includes first to third memories, and each of the first to third memories is provided with one second data signal R ′, G ′, and B ′. The memory unit 231 is n-bit for outputting the n-bit second data signal (R ', G', B ') as the compensated m-bit third data signal (R ", G", B ") A look-up table having m bits of compensation data mapped one-to-one to second data signals R ', G', and B 'is stored, wherein n and m are natural numbers and the first to third memories. Each may be formed of ROM or RAM.

The dithering unit 231 may process n-bit third data signals R ″, G ″, and B ″ read from the memory unit 231 in the display panel unit 300 illustrated in FIG. 1. Dithers the third data signals R ″, G ″, and B ″ to output them to the display panel 300.

The first memory and the first dithering unit constitute an R gradation compensator for compensating the input R data signal, and the second memory and the second dithering unit compose a G gradation compensator for compensating the input G data signal. The third memory and the third dithering unit constitute a B gray level compensating unit that compensates the input B data signal.

The gradation compensator 230 further includes a memory unit 231 that performs gradation compensation to improve color reproducibility and color temperature, thereby increasing current consumption. Thus, the gray level compensator 230 is driven in the second driving mode in which the limit of the current consumption is relatively small.

FIG. 3 is a detailed block diagram of a gradation compensator of FIG. 1, wherein the gradation compensator has compensation data mapped according to a degree of deviation between input data and previous frame data corresponding to the input data. A DCC circuit for outputting compensation data of the input data using a look-up table.

Referring to FIG. 3, the grayscale compensator 230 according to the second exemplary embodiment of the present invention may include an input buffer 233, a first memory 234, a first memory controller 235, a second memory 236, and An output buffer 237 is included.

The input buffer 233 bundles n input second data signals R ', G', and B 'into predetermined m-bit signals corresponding to the data processing speed thereafter.

The first memory 234 stores m-bit signals output from the input buffer 233. In this case, the m-bit signal may be stored in units of frames.

The first memory controller 235 controls writing and reading of m bits of data stored in the first memory 234. That is, the m-bit data signal Gi output from the input buffer 233 is written to the first memory 234 and corresponds to the m-bit data signal Gi output from the input buffer 233. The m-bit data signal Gi-1 of the previous frame is read from the first memory 234. Here, n and m are natural numbers.

The second memory 236 has a look up table in which compensation data corresponding to an input signal is mapped one-to-one. That is, the second memory 236 is the upper k bits of the m-bit current data signal Gi output from the input buffer 233 and the m-bit previous data signal Gi read from the first memory 234. A look-up table having compensation data Gj mapped one-to-one to a 2k-bit data signal Gj according to the combination of the upper k bits of -1) is stored. Here, i, j and k are natural numbers, and the second memory may be formed of a ROM or a RAM.

The output buffer 237 is an n-bit third data signal R ″ capable of processing the m-bit compensation data Gj read from the second memory 236 by the display panel 300 shown in FIG. 1. , G ", B") and output it.

Since the gray level compensator 230 has a configuration that further includes a plurality of memories 234 and 236 as described above, the current consumption increases. Thus, the gray level compensator 230 is driven in the second driving mode in which the limit of the current consumption is relatively small.

Referring back to FIG. 1, the power supply unit 240 includes the common voltages Vcom and Vcst, the gate on / off voltages Von and Voff and the analog driving voltage AVDD provided to the display panel unit 300. To provide. In addition, when the display device is driven in the second driving mode, the power supply 240 may output an analog driving voltage boosted by a predetermined level compared to the analog driving voltage provided in the first driving mode.

The display panel unit 300 includes a display unit 310, a data driver 320, and a gate driver 330.

The display unit 310 has an array substrate, an opposing substrate, and a liquid crystal layer interposed between the substrates. The array substrate has a plurality of data lines DL1, ..., DLM and a plurality of gate lines GL1, ..., GLM that are interconnected with the data lines DL1, ..., DLM. It has a plurality of pixels defined by the data line and the gate line. The pixel has a switching element TFT, a liquid crystal capacitor CLC, and a storage capacitor CST. The gate electrode of the switching element TFT is connected to the gate line, the source electrode is connected to the data line, and the drain electrode is connected to the pixel electrode which is the first electrode of the liquid crystal capacitor CLC. The storage capacitor CST uses the pixel electrode as the first electrode and the common electrode Vcst as the second electrode.

The opposing substrate has a color filter for expressing color at a position corresponding to the pixel and has a common electrode Vcom which is a second electrode of the liquid crystal capacitor CLC.

The data driver 320 may include the third data signal R ″, G ″, B ″ provided from the gray level compensator 230 or the second data signal R ′, provided from the timing controller 210. G 'and B' are converted into analog data signals and output to the display unit 310 based on the first timing signal TS1 provided by the timing controller 210.

The gate driver 330 may display gate on / off voltages Von and Voff provided from the power supply 240 based on the second timing signal TS2 provided by the timing controller 210. Output to 310.

4 is a diagram for describing a method of driving a display device according to an exemplary embodiment.

1 to 4, the system unit 100 drives in one driving mode of a first driving mode using a portable power source and a second driving mode using an external power source.

First, when the system unit 100 operates in the first driving mode, the system unit 100 outputs a first mode signal SM1 indicating the first driving mode to the panel driver 200. (S100). The first mode signal SM1 is provided to the timing controller 210 included in the panel driver 200, and the timing controller 210 reads the first mode signal SM1 (S110). The panel driving unit 200 and the display panel unit 300 are driven in the first driving mode.

According to the first driving mode, the driving of the panel driving unit 200 and the display panel unit 300 will be described below (S120).

The first data signals R, G, and B provided by the system unit 100 are output timing by control signals Vsync and Hsync controlling the output of the first data signals R, G, and B. The controlled second data signals R ′, G ′, and B ′ are provided to the display panel 300.

In this case, the gray voltage generator 220 generates a gray voltage using the analog driving voltage AVDD provided by the power supply 240 as a reference voltage and provides the gray voltage to the data driver 320.

The data driver 320 converts the gray voltage and the second data signals R ′, G ′, and B ′ into analog data signals and provides the first timing signal TS1 provided by the timing controller 210. ) Is output to the display unit 310 on the basis of.

The second data signals R ′, G ′, and B ′ are provided to the data driver 320 of the display panel 300, and the gray voltage and the timing controller provided from the gray voltage generator 220. Based on the first timing signal TS1 provided by 210, the signal is converted into an analog data signal and output to the display unit 310.

In addition, the power supply unit 240 provides gate on / off voltages Von and Voff to the gate driver 330, and the gate on / off voltages Von and Voff are provided by the timing controller 210. The timing signal TS2 is sequentially provided to the display panel 310. Accordingly, the display panel 310 displays a predetermined image by an analog data signal and gate on / off voltages Von and Voff provided by the data driver 320 and the gate driver 330, respectively.

Thereafter, the timing controller 210 waits to provide the changed mode signal in order to determine the driving mode of the system unit 100 (S140).

Next, when the system unit 100 operates in the second driving mode, the system unit 100 transmits a second mode signal SM2 indicating the second driving mode to the panel driving unit 200. Output (S100). The second mode signal SM2 is provided to the timing controller 220 included in the panel driver 200, and the timing controller 220 reads the second mode signal SM2 (S110). The panel driver 200 and the display panel 300 are controlled to be driven in the second driving mode.

According to the second driving mode, the driving of the panel driving unit 200 and the display panel unit 300 will be described as follows (S130).

The first data signal (R, G, B) provided by the system unit 100 is output by control signals (Vsync, Hsync) for controlling the output of the first data signal (R, G, B) The timing-controlled second data signals R ', G', and B 'are provided to the gray level compensator 230.

The second data signals R ', G', and B 'provided to the gray level compensator 230 may be a third data signal having gray level compensation through the ACC circuit shown in FIG. 2 or the DCC circuit shown in FIG. R ″, G ″, B ″) to the display panel unit 300.

In this case, the gray voltage generator 220 generates the gray voltage as a reference voltage from the analog driving voltage AVDD provided by the power supply 240 and provides the gray voltage to the data driver 320.

The data driver 320 converts the third data signal R ″, G ″, B ″ into an analog data signal and based on the first timing signal TS1 provided from the timing controller 210. Output to the display unit 310.

The third data signals R ″, G ″, and B ″ are provided to the data driver 320 of the display panel 300, and the gray voltage and the timing controller provided by the gray voltage generator 220. Based on the first timing signal TS1 provided at 210, the signal is converted into an analog data signal and output to the display unit 310.

In addition, the power supply unit 240 provides gate on / off voltages Von and Voff to the gate driver 330, and the gate on / off voltages Von and Voff are provided by the timing controller 210. The timing signal TS2 is sequentially provided to the display panel 310. Accordingly, the display panel 310 displays a predetermined image by an analog data signal and gate on / off voltages Von and Voff provided by the data driver 320 and the gate driver 330, respectively.

Thereafter, the timing controller 210 waits to provide the changed mode signal in order to determine the driving mode of the system unit 100 (S140).

In summary, the system unit 100 provides the driving mode information of the system unit 100 to the panel driving unit 200, and the panel driving unit 200 reads the driving mode information to read the driving mode information. The display panel 300 is driven in a corresponding driving mode.

In this case, when the system unit 100 is in the first driving mode using a portable power source, the panel driver 200 has a relatively large current consumption limit, and thus the display panel unit 300 may be driven by a method in which current consumption is small. ).

In addition, when the system unit 100 is in the second driving mode using an external power source, the panel driving unit 200 may be driven at a high image quality because the limit of the current consumption is relatively low. Gradation compensation is performed to display an image. Here, the gray level compensator 230 further includes memories including a look up table having compensation data for performing gray level compensation as illustrated in FIGS. 2 and 3, so that current consumption is higher than that of the first driving mode. Will increase.

In addition, in the second driving mode, the panel driver 200 boosts the analog driving voltage AVDD by the power supply 240 to improve the response speed of the liquid crystal included in the display panel 310. You can also provide

Therefore, when the system unit 100 is driven in the first driving mode, the display device is driven with a low current consumption, and when the system unit 100 is driven in the second driving mode, to display an image with high quality. Drive the display device with high current consumption.

According to this driving method, when driving in the second driving mode, the panel driving unit 100 may be connected to the display panel unit regardless of whether the system unit 100 changes to a power saving mode, for example. The high quality current can be displayed by using the 310 as the high current consumption.

In the embodiments of the present invention, the ACC circuit and the DCC circuit have been described as an example in order to drive the display device with high image quality, but the technical concept of the present invention is not limited thereto. That is, when driving the display device using an external power source within the scope of the technical idea of the present invention, various methods and circuits for displaying a high quality image without limiting current consumption may be additionally configured.

According to the present invention as described above, when driving the display device using a portable power supply, driving the display panel with a low current consumption can achieve a low power consumption, when driving the display device using an external power supply, By driving the display panel with a high current consumption, a high-quality image can be displayed on the display panel.

Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art will variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. I can understand that you can.

Claims (8)

In a method of driving a display device having a display panel, Determining whether the current driving mode is a driving mode using a portable power source and a driving mode using an external power source, based on the input mode signal; And In the driving mode using the external power source, driving the display panel with a relatively higher current consumption than the driving mode using the portable power source. The method of claim 1, wherein the driving with the high current consumption comprises: Converting the input data signal into compensation data signals classified according to colors and outputting the compensation data signals; And And converting the compensation data signal into an analog data signal and outputting the compensation data signal to the display panel. The method of claim 1, wherein the driving with the high current consumption comprises: Outputting a compensation data signal corresponding to the input data signal and the data signal of the previous frame; And And converting the compensation data signal into an analog data signal and outputting the compensation data signal to the display panel. The method of claim 1, wherein the driving with the high current consumption comprises: Boosting and outputting an analog driving voltage; And And converting the compensation data signal into an analog data signal using the boosted analog driving voltage and outputting the converted data signal to the display panel. A display panel displaying an image; A timing controller determining whether the current driving mode is a driving mode using a portable power source and a driving mode using an external power source through an input mode signal; A gray level compensator for converting an input data signal into a compensation data signal in a driving mode using the external power source; And And a data driver converting the compensation data signal into an analog data signal and outputting the compensation data signal to the display panel. The method of claim 5, wherein the gray level compensation unit An R gray scale compensator configured to output a corresponding R compensation data signal using a first lookup table to which an R compensation data signal corresponding to the input R data signal is mapped; A G gray scale compensator configured to output a corresponding G compensation data signal using a second lookup table to which a G compensation data signal corresponding to the input G data signal is mapped; And And a B gray level compensator configured to output a corresponding B compensation data signal by using a third lookup table to which the B compensation data signal corresponding to the input B data signal is mapped. The method of claim 5, wherein the gray level compensation unit And a lookup table configured to store a compensation data signal mapped to an input data signal and a data signal of a previous frame, and output a compensation data signal corresponding to the input data signal using the lookup table. Display device. The display device of claim 5, further comprising a power supply unit configured to boost the analog driving voltage input to the data driver to a predetermined level and output the voltage.

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