KR20070018721A - Liquid crystal display device, method for controlling display data for liquid crystal display device, and recording media - Google Patents

Abstract

Provided is a liquid crystal display device using liquid crystal such as OCB mode liquid crystal capable of reducing power consumption at low cost.

A liquid crystal display panel 10 having a signal line and a scanning line arranged in a matrix shape, a gate driver 12 for supplying a gate signal to the scanning line, a shift register 22 for outputting image data in an image display period, and each pixel electrode D / A conversion of data acquired from the second data storage section 23, the shift register 22, and the second data storage section 23, in which second data independent of the image data, which is applied to the video data is stored, to supply a voltage to the signal line. A source driver 11 having a D / A conversion section 21 and a timing for inputting image data to the shift register 22 from an input video signal, and the D / A conversion section 21 provides a shift register 22. The timing control part 32 which controls the timing which acquires the image data from the data, and the timing which the D / A conversion part 21 acquires 2nd data from the 2nd data storage part 23 is provided.

Gate driver, OCB mode, liquid crystal panel, image gradation, RGB signal, image data, reverse transition, double speed conversion

Description

Liquid crystal display device, display data control method of liquid crystal display device and recording medium {LIQUID CRYSTAL DISPLAY DEVICE, METHOD FOR CONTROLLING DISPLAY DATA FOR LIQUID CRYSTAL DISPLAY DEVICE, AND RECORDING MEDIA}

1 is a block diagram showing the configuration of a liquid crystal display device of a first embodiment of the present invention.

Fig. 2 is a diagram showing a timing chart showing the flow of display data when the reverse transition prevention driving is performed in the liquid crystal display device of the first embodiment of the present invention.

3 is a block diagram showing another configuration of the liquid crystal display device of the first embodiment of the present invention.

4 is a block diagram showing a configuration of a liquid crystal display device of a second embodiment of the present invention.

Fig. 5 is a diagram showing a timing chart showing the flow of display data when performing reverse transition prevention driving in the liquid crystal display device of the second embodiment of the present invention.

(A) is a figure which shows the bend state in the case of a white display of an OCB liquid crystal, (b) is a figure which shows the bend state in the case of a black display of an OCB liquid crystal, (c) is a figure of an OCB liquid crystal A diagram showing the spray state.

Fig. 7 is a diagram showing an example of a timing chart of a video signal, a double speed signal, and a gate pulse in a conventional liquid crystal display device during reverse transition prevention driving by double speed conversion.

Fig. 8 is a block diagram of a conventional liquid crystal display device which performs reverse transition prevention driving by double speed conversion.

Fig. 9 is a diagram showing a timing chart showing the flow of display data when performing reverse transition prevention driving by double speed conversion in a conventional liquid crystal display device.

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

10 liquid crystal display panel

11: source driver

12: gate driver

13: controller

14: input power

15: liquid crystal drive voltage generation circuit

21: D / A converter

22: shift register

23: black display register

24: black data storage

31, 34, 35: signal processing unit

32: timing controller

33: black gradation memory

[Patent Document 1] Japanese Patent Application Laid-Open No. 2003-280617

The present invention relates to a liquid crystal display device, a data control method thereof, and a recording medium. For example, the present invention relates to a liquid crystal display device using an OCB mode liquid crystal, a display data control method thereof, and a recording medium.

Liquid crystal display devices are thin, lightweight, and replace conventional CRTs, and their use is expanding in recent years. However, TN (Twisted Nematic) oriented liquid crystal display panels which are widely used at present have a narrow viewing angle and a high response speed, resulting in inferior image quality than CRTs, such as a trailing tail when displaying moving images.

On the other hand, in recent years, the liquid crystal display device provided with the liquid crystal display element of the OCB (Optically Compensated Birefringence) mode which has the characteristic of a fast response and a high viewing angle is used. This liquid crystal display device bends a liquid crystal to perform visual compensation, and further combines an optical phase compensation film to obtain a wide viewing angle.

It is sectional drawing which shows typically the orientation state of the liquid crystal molecule which the liquid crystal display element of OCB mode has. 6 (a) and 6 (b) are cross-sectional views illustrating a voltage application state, and FIG. 6 (c) is a cross-sectional views illustrating a voltage non-application state.

The nematic liquid crystal is inject | poured between the glass substrate 91 of the liquid crystal display panel which comprises the liquid crystal display device using the liquid crystal display element of OCB mode, as shown as liquid crystal molecules 92 etc. of FIG. . And the alignment state of the liquid crystal which is not applying the voltage is called the spray state 93. When the power supply of the liquid crystal display device using the liquid crystal display element of OCB mode is turned on, it is necessary to perform driving called transition driving. In other words, the transition drive is a spray voltage 93 shown in FIG. 6C by applying a relatively large voltage of about 20 to 25 volts to the liquid crystal layer when the liquid crystal display is turned on. (a) and drive to transition to the bend states 94a and 94b shown in Fig. 6B. The display using the bend states 94a and 94b is a feature of the liquid crystal display device using the liquid crystal display element of the OCB mode. The transmittance of the panel is changed by changing the bend state according to the magnitude of the voltage.

The bend state 94a shown in FIG. 6A shows a bend state in the case of displaying a white display, and the bend state 94b in FIG. 6B shows a bend in the case of displaying black. It shows the state.

Moreover, in the liquid crystal display device using the liquid crystal display element of OCB mode, when the voltage of 2 volts or less is continuously applied to this liquid crystal display panel, the orientation state of a liquid crystal will be spray state 93 from the bend state 94a, 94b. Gradually transition to hereinafter (hereinafter referred to as reversal). In order to prevent such reverse transition, the drive called a reverse transition prevention drive is performed in the liquid crystal display device using the liquid crystal display element of OCB mode.

That is, in the case of the normally white mode liquid crystal display device which performs white display when a relatively low voltage is applied and performs black display when a relatively high voltage is applied, the reverse transition prevention driving is periodically displayed on each pixel. It is a drive to prevent reverse transition by applying a voltage corresponding to black separately from the video signal. In the reverse transition prevention driving, there is a reverse transition prevention driving called double speed conversion in which an operation of applying a voltage corresponding to black to an pixel and an operation of applying a voltage corresponding to a video signal are alternately performed to prevent reverse transition. (See, for example, Patent Document 1). Therefore, in the liquid crystal display device using the liquid crystal display element of the OCB mode, the display period in which the voltage corresponding to the video signal is applied to the pixel and the reverse transition prevention are prevented in the period of displaying the image of one frame (or one field). For this reason, a black insertion period in which a voltage corresponding to black is applied to the pixel is set.

Hereinafter, the operation of the reverse transition prevention driving by the double speed conversion will be described.

FIG. 7 shows an example of a timing chart of a video signal, a double speed signal, and a gate pulse during the reverse transition prevention driving by double speed conversion.

With respect to a video signal input as RGB data, black gradation data for black insertion at the front side of the 1H period and RGB data obtained by converting the video signal at double speed at the rear side for each horizontal period (1H period), respectively. It is stored in the source driver's shift register to be stored. In addition, the part shown with the oblique line of FIG. 7 has shown black-gradation data for black insertion.

For each 1H period, data for one row of pixels is sequentially input to the shift register, and data for one row of pixels is simultaneously output from the source driver. Therefore, as shown in FIG. 7, the input video signal is output from the source driver at a timing delayed by 1H period.

G1 to G10 in Fig. 7 show gate signals output from the gate driver to the respective gate lines. The symbol shown on the right side of each gate signal indicates the type of display signal or black insertion data B written in the image cell at the timing when each gate signal becomes high.

At the timing when the display signal S1 is output from the source driver, the gate signal of the gate line G1 becomes high, and the display signal S1 is written into the image cell on the gate line G1. Next, at the timing when the black insertion data inserted between the display signal S1 and the display signal S2 is output from the source driver, the gate signal of the gate line G7 becomes high, and the gate line G7 Black insertion data is written into the image cells of the image. Next, at the timing when the display signal S2 is output from the source driver, the gate signal of the gate line G2 becomes high, and the display signal S2 is written into the image cell on the gate line G2. Next, at the timing when the black insertion data inserted between the display signal S2 and the display signal S3 is output from the source driver, the gate signal of the gate line G8 becomes high, and the gate line G8 Black insertion data is written into the image cells of the image. In the same manner below, a display signal or black insertion data is written into each image cell in accordance with the timing at which the gate signal of each gate line becomes high.

In this way, each gate line G1 to G10 is selected twice each in one field period, and the display signal and black insertion data are written once to the image cells on each gate line G1 to G10. Therefore, the reverse transition prevention driving which writes the display signal and writes black insertion data periodically can be realized.

As a result, in the example shown in FIG. 7, the ratio of the video display period T1 to the black insertion period T2 is set to 9:11. The ratio of the video display period T1 to the black insertion period T2 is changed by changing the timings of the pulses for writing the display signal and the pulses for writing black insertion data of the gate signals of the gate lines G1 to G10. Can be adjusted.

Fig. 8 shows a block diagram of a liquid crystal display device which performs the conventional anti-reversal driving by double speed conversion. FIG. 9 shows a timing chart showing the flow of display data when the liquid crystal display of FIG. 8 performs reverse transition prevention driving due to double speed conversion.

The liquid crystal display device includes a liquid crystal display panel 110, a source driver 111, a gate driver 112, a controller 113, an input power supply 114, and a liquid crystal drive voltage generation circuit 115.

The liquid crystal display panel 110 is a liquid crystal display panel in which signal lines and scanning lines are arranged in a matrix, and liquid crystal display elements of the OCB mode are formed at their intersections.

The gate driver 112 supplies a gate signal to the scan line of the liquid crystal display panel 110, and the source driver 111 supplies a voltage corresponding to the display data to the signal line of the liquid crystal display panel 110.

The input power supply 114 supplies electric power to the controller 113 and the liquid crystal drive voltage generation circuit 115, and the liquid crystal drive voltage generation circuit 115 causes the display data to be displayed on the liquid crystal display panel 110. Accordingly, the voltage supplied to the liquid crystal display panel 110, the source driver 111, and the gate driver 112 is adjusted.

The controller 113 includes a signal processor 131, a line memory 133, and a timing controller 132, and the source driver 111 includes a D / A converter 121 and a shift register 122. Doing. In addition, the signal processing unit 131 of the controller 113 has a black gradation storage unit 134. The black gradation storage unit 134 is a storage element such as an EEPROM and stores gradation information of black display data to be inserted for preventing reverse transition.

8 and 9, the details of the operation of the reverse transition prevention drive by the double speed conversion will be described.

When the video signal which is RGB data is input to the signal processing unit 131, the signal processing unit 131 performs gray level correction or gamma correction processing on the input video signal, converts it into a double speed signal, and converts the line memory 133 into a double speed signal. Store in As shown in Fig. 9, for each data of one horizontal period (1H period), the front side of the 1H period is the black data for black insertion, and the rear side is the double-speed video signal so that the line memory 133 Save to. At this time, the signal processing unit 131 generates black data for black insertion stored in the front side of the 1H period based on the gray scale information stored in the black gray scale storage unit 134, and stores the black data in the line memory 133. Goes.

In addition, the timing controller 132 of the controller 113 outputs a start pulse at a timing at which the display signals S1 to S4 included in the video signal are inputted, and outputs a start pulse for one row of pixels stored in the line memory 133. The transfer of data to the shift register 122 of the source driver 111 is started. Here, by using the double speed clock, data for one row of pixels is sequentially transferred from the line memory 133 to the shift register 122 at double speed.

Next, the timing control part 132 of the controller 113 supplies the D / A converter 121 of the source driver 111 before the timing which outputs the start pulse which starts the transmission of the next display signal contained in a video signal. Outputs a load pulse. At the timing at which the load pulse is input, the D / A converter 121 acquires data stored in the shift register 122 at the same time for one row of pixels, performs D / A conversion, and displays the voltage corresponding to each display data. The signal is output to the signal line of the panel 110.

Since the load pulse is output at the timing just before the next display signal is input, the timing output from the source driver 111 to the signal line of the liquid crystal display panel 110 is input to the controller 113 as shown in FIG. 9. The video signal is output at a timing delayed by 1H period.

In this way, the reverse transition prevention drive by double-speed conversion is implement | achieved.

In the above description, the double speed conversion drive has been described as the purpose of realizing black data insertion for preventing the inversion of the OCB mode liquid crystal. However, the double speed conversion drive described in FIGS. 9 to 11 is the OCB mode liquid crystal. It is used not only for the prevention of reverse transition but also for improving the visibility of moving images.

That is, when it aims at the improvement of moving image visibility, the above-mentioned double speed conversion drive is used also in the liquid crystal display device which used liquid crystals other than OCB mode liquid crystal, for example, the liquid crystal display device which used the TN orientation liquid crystal display panel. By using the double-speed conversion drive, black data is inserted and displayed while displaying the display data, so that phenomena such as a trailing tail can be alleviated during moving image display.

In a liquid crystal display device using an OCB mode liquid crystal, for the purpose of improving moving image visibility, the ratio of the black insertion period (the length of the period of T2 in FIG. 7) is generally longer than that in the case of only the inversion prevention. do.

However, in the above-described conventional double speed conversion drive, the processing of double speed conversion is required in the controller 113, and the transfer of display data from the line memory 133 to the shift register 122 is also performed at high speed. Power consumption at the 113 and the source driver 111 was large.

In addition, since the signal processing unit 131 needs to perform the double speed conversion process at a high speed, the controller 113 requires a high performance and a line memory 133 must be formed, so that the cost has been increased.

In addition, with the high data transfer speed from the line memory 133 to the shift register 122, a high frequency noise problem has also occurred. In practice, in high-pixel panels, it is common to devise a scheme that slows down the transmission speed by using a known technique such as doubling the transmission bus width to the source driver, and simply doubling the clock is not desirable in high-pixel panels. not.

An object of the present invention is to provide a liquid crystal display, a display data control method thereof, and the like, which can solve the conventional problems described above, which can reduce power consumption.

In order to solve the problem mentioned above, 1st this invention,

A liquid crystal display panel having signal lines and scanning lines arranged in a matrix, and pixel electrodes formed corresponding to intersections of the signal lines and the scanning lines;

A gate driver for supplying a gate signal to the scan line;

A second register in which image data for display in the image display period is sequentially inputted for one row of pixels, and simultaneously outputs one row of pixels; and a second stored second data independent of the image data applied to the respective pixel electrodes. A source driver having a data storage section and a D / A converter section for supplying a voltage to the signal line by performing D / A conversion on the video data acquired from the shift register and the second data acquired from the second data storage section; ,

A first timing for inputting the video data included in the input video signal to the shift register, wherein the D / A converter is configured to acquire the video data from the shift register and perform D / A conversion to supply voltage to the signal line; And a timing control unit configured to control a second timing and a third timing in which the D / A converter acquires the second data from the second data storage unit, performs D / A conversion, and supplies a voltage to the signal line. It is a liquid crystal display device.

Moreover, 2nd this invention,

The second data is the liquid crystal display device of the first invention, which is data for displaying at least one kind of predetermined video gray scales.

In addition, the third present invention,

The second data is the liquid crystal display of the first invention, which is black data for display in a black insertion period in a normally white mode.

In addition, the fourth invention,

The liquid crystal used for the said liquid crystal display panel is the liquid crystal display device of 3rd this invention which is OCB mode liquid crystal.

In addition, the fifth invention,

Further comprising a second data generating unit for generating the second data,

The timing controller is a liquid crystal display of the first invention which controls the second data generated by the second data generator to be input to the second data storage unit in a blanking period of the input video signal. .

In addition, the sixth present invention,

The second data generation unit is a liquid crystal display of the fifth aspect of the invention for generating the second data from each of gray level data of R, G, and B individually set.

In addition, the seventh invention,

A liquid crystal display device of the first aspect of the present invention, further comprising a second data generation unit for generating the second data and inputting the second data storage unit regardless of the input of the video signal when the power is turned on.

In addition, the eighth aspect of the present invention,

The second data generation unit is a liquid crystal display of the seventh aspect of the present invention which generates the second data from the grayscale data of R, G, and B individually set.

In addition, a ninth invention,

The second data of the second data storage unit is a liquid crystal display device of the first present invention which is stored in advance.

In addition, a tenth invention,

A liquid crystal display panel having a signal line and a scan line arranged in a matrix shape, and a pixel electrode formed corresponding to the intersection of the signal line and the scan line, a gate driver for supplying a gate signal to the scan line, and a signal line during the video display period. A source driver for supplying a first voltage corresponding to the gray level of the image data and supplying a second voltage corresponding to the gray level of the second data independent of the image data to the signal line in a predetermined period not including the video display period. As a display data control method of a liquid crystal display device having:

Inputting the image data included in the input image signal to a shift register of the source driver, which sequentially inputs the image data for display in the image display period and outputs one row of pixels at the same time A video data input timing control step of controlling timing;

In the video display period, the video data stored in the shift register is subjected to D / A conversion to supply the first voltage to the signal line, and in the predetermined period, it is stored in a second data storage part of the source driver. An output timing control step of controlling timing to perform D / A conversion of second data to supply the second voltage to the signal line.

In addition, the eleventh present invention,

The second data is a display data control method of the liquid crystal display device of the tenth aspect of the present invention, which is data for displaying at least one or more types of predetermined video gray levels.

In addition, the twelfth invention,

The second data is a display data control method of the liquid crystal display device of the tenth present invention which is black data for display in the black insertion period in the normally white mode.

In addition, a thirteenth present invention,

The liquid crystal used for the said liquid crystal display panel is a display data control method of the liquid crystal display device of the twelfth invention which is an OCB mode liquid crystal.

In addition, a fourteenth aspect of the present invention,

In the video display period of the display data control method of the liquid crystal display device of the present invention, the first voltage is supplied to the signal line by D / A conversion of the video data stored in the shift register. And functioning a computer to execute the output timing control step of controlling timing to D / A-convert the second data stored in the second data storage to supply the second voltage to the signal line. It is a recording medium that records a program.

Moreover, invention which concerns on this invention,

In the video display period of the display data control method of the liquid crystal display device of the present invention, the first voltage is supplied to the signal line by D / A conversion of the video data stored in the shift register. And program for operating a computer to execute the output timing control step of controlling timing to D / A-convert the second data stored in the second data storage to supply the second voltage to the signal line. to be.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described, referring drawings.

(First embodiment)

1 is a block diagram showing the configuration of a liquid crystal display device of a first embodiment of the present invention.

The liquid crystal display device of the first embodiment includes a liquid crystal display panel 10, a source driver 11, a gate driver 12, a controller 13, an input power source 14, and a liquid crystal drive voltage generation circuit 15. Doing.

The liquid crystal display panel 10 is a liquid crystal display panel of normally white mode in which signal lines and scanning lines are arranged in a matrix, and pixel electrodes and liquid crystal display elements in OCB mode are formed at corresponding positions of their intersections.

The gate driver 12 supplies a gate signal to the scan line of the liquid crystal display panel 10, and the source driver 11 supplies a voltage corresponding to the display data to the signal line of the liquid crystal display panel 10.

The input electrode 14 supplies electric power to the controller 13 and the liquid crystal drive voltage generation circuit 15, and the liquid crystal drive voltage generation circuit 15 at a timing of causing display data to be displayed on the liquid crystal display panel 10. Therefore, the voltage supplied to the liquid crystal display panel 10, the source driver 11, and the gate driver 12 is adjusted.

The controller 13 includes a signal processor 31 and a timing controller 32. The source driver 11 includes a D / A converter 21, a shift register 22, and a black display register 23. ). In addition, the signal processing unit 31 of the controller 13 has a black gradation storage unit 33. The black gradation memory 33 is a storage element such as an EEPROM, and stores gradation information of black display data to be inserted to prevent reverse transition. In the tone information of the black display data stored in the black tone storage unit 33, the tone information of R, G, and B is individually set. In addition to the gradation information of the black display data, the storage element such as the EEPROM stores the setting value of each register, data for changing the driving timing, and the like.

In addition, black display data inserted for preventing reverse transition corresponds to an example of the second data of the present invention, and the black display register 23 corresponds to an example of the second data storage unit of the present invention. In addition, the signal processing part 31 corresponds to an example of the 2nd data generation part of this invention.

FIG. 2 shows a timing chart showing the flow of display data when performing the inversion prevention drive in which black display is inserted in the liquid crystal display device of the first embodiment shown in FIG.

Hereinafter, the operation of the reverse transition prevention driving in the liquid crystal display device of the first embodiment will be described with reference to FIGS. 1 and 2.

When the video signal of RGB data is input to the signal processing part 31 of the controller 13, the signal processing part 31 performs gradation correction or gamma correction process with respect to the input video signal.

The timing controller 32 of the controller 13 outputs a start pulse 1 at a timing at which the respective display signals S1 to S4 included in the video signal are inputted, and outputs a start pulse 1 to the display signal processed by the signal processor 31. The transfer to the shift register 22 is started. Here, the display signal processed by the signal processing unit 31 is sequentially transmitted to the shift register 22 as it is without performing double-speed conversion processing. Therefore, the display signal is transmitted from the signal processor 31 to the shift register 22 at the same speed (1x speed) as the video signal input to the controller 13.

In addition, the display signal processed by the signal processing part 31 corresponds to an example of the video data of this invention. The timing at which the timing controller 32 outputs the start pulse 1 corresponds to an example of the first timing of the present invention. In addition, the process which the timing control part 32 outputs the start pulse 1, and starts to transmit a display signal to the shift register 22 is an example of the video data input timing control step of this invention.

In addition, the timing controller 32 of the controller 13 outputs a start pulse 2 at the start timing of the blanking period included in the input video signal, and outputs black display data for black insertion for preventing reverse transition. The processor 31 transfers the data to the register 23 for black display. At this time, black display data for black insertion generated in the signal processing unit 31 is transferred to the black display register 23 based on the gray scale information stored in the black gray storage unit 33. Here, the black display register 23 may be a register that is not provided with a shift function that is provided with a shift register 22 that sequentially stores input data for each pixel and outputs the same at the time of output.

Next, the timing control part 32 of the controller 13 has the D / A conversion part 21 of the source driver 11 before the timing which outputs the start pulse 1 which starts the transmission of the next display signal contained in a video signal. Outputs the load pulse 1 for. The D / A converter 21 acquires a display signal stored in the shift register 22 simultaneously for one row of pixels at the timing at which the load pulse 1 is input, and performs a D / A conversion to obtain a voltage corresponding to each display signal. The signal is output to the signal line of the liquid crystal display panel 10.

In addition, the voltage corresponding to each display signal output to the signal line of the liquid crystal display panel 10 at this time corresponds to an example of the 1st voltage of this invention. The timing at which the timing controller 32 outputs the load pulse 1 to the D / A converter 21 corresponds to an example of the second timing of the present invention.

In addition, the timing controller 32 of the controller 13 applies the load pulse 2 to the D / A converter 21 of the source driver 11 at the timing of inserting the black display for preventing reverse transition within the 1H period. Output The D / A converter 21 acquires black display data stored in the black display register 23 at the same time for one row of pixels at the timing at which the load pulse 2 is input, and performs D / A conversion to correspond to the black gray level. The voltage is output to the signal line of the liquid crystal display panel 10.

In addition, the voltage corresponding to the black gray level output to the signal line of the liquid crystal display panel 10 at this time corresponds to an example of the 2nd voltage of this invention. The timing at which the timing controller 32 outputs the load pulse 2 to the D / A converter 21 corresponds to one example of the third timing of the present invention. In addition, the process which the timing control part 32 outputs the load pulse 1 and the load pulse 2, and controls the D / A conversion part 21 is an example of the output timing control step of this invention.

In this manner, as shown in FIG. 2, black display data is inserted and output between the display signals from the source driver 11 to the liquid crystal display panel 10.

Since the load pulse 1 is output at the timing just before the next display signal is input, as shown in FIG. 2, the display signal S1 before one at the input start timing of the display signal S2 included in the video signal. Is output from the source driver 11. In this manner, the timing output from the source driver 11 to the signal line of the liquid crystal display panel 10 is output at a timing delayed by 1H period with respect to the video signal input to the controller 13.

Since the black insertion period is determined by the output timing of the load pulse 2, the ratio of the black insertion period to the display period can be adjusted by changing the output timing of the load pulse 2. Faster output timing of load pulse 2 in the 1H period increases the ratio of the black insertion period, and slower decreases the ratio of the black insertion period.

In addition, a display period corresponds to an example of the video display period of this invention, and a black insertion period corresponds to an example of the predetermined period which does not contain the video display period of this invention.

It is known that in the OCB mode liquid crystal device, reverse transition easily occurs as the temperature increases. For example, the timing controller 32 changes the output timing of the load pulse 2 based on the temperature of the liquid crystal display panel 10 and changes the ratio of the black insertion period, thereby preventing reverse transition even if the temperature changes. A liquid crystal display device can be realized.

In addition, since the output from the source driver 11 in each black insertion period is the same, the D / A conversion unit 21 repeatedly acquires the black display data stored in the black display register 23 once. You may make it output from the source driver 11. That is, in FIG. 2, although black display data acquired in the blanking period of each 1H period is used as black data to insert next, black display of "black 1" acquired from the blanking period before display signal S1, for example. The data may be used for black data to be inserted after subsequent display signals S2, S3, ....

3 is a block diagram showing another configuration of the liquid crystal display device of the first embodiment. The same reference numerals are used for the same components as in FIG. 1.

The liquid crystal display of FIG. 3 stores the black display data for black insertion in the black display register 23 when the power is turned on, and displays the black display data on the liquid crystal display panel 10. It is a display device.

The operation of the liquid crystal display device shown in FIG. 3 will mainly be described with respect to the differences from the liquid crystal display device shown in FIG. 1.

When the power supply of the liquid crystal display device is turned on, the signal processing unit 34 of the controller 13 uses the black color for black insertion based on the gradation information stored in the black gradation storage unit 33 regardless of the presence or absence of a video signal input. Black display data is generated, and the generated black display data is transferred to the black display register (23). That is, black display data is transferred and stored from the controller 13 to the black display register of the source driver 11 only once when the power is turned on. The signal processor 34 corresponds to an example of the second data generator of the present invention.

When the video signal of the RGB data is input to the signal processing unit 34 of the controller 13, the signal processing unit 34 performs gradation correction or gamma correction processing on the input video signal.

The timing controller 32 of the controller 13 outputs a start pulse 1 at a timing at which the respective display signals S1 to S4 included in the video signal are inputted, and outputs a start pulse 1 to the display signal processed by the signal processor 34. The transfer to the shift register 22 is started. Here, the display signal processed by the signal processing unit 34 is sequentially transmitted to the shift register 22 without performing double speed conversion processing. Therefore, the display signal is transmitted from the signal processing unit 34 to the shift register 22 at the same speed (1x speed) as the video signal input to the controller 13.

Next, the timing control part 32 of the controller 13 has the D / A conversion part 21 of the source driver 11 before the timing which outputs the start pulse 1 which starts the transmission of the next display signal contained in a video signal. Outputs the load pulse 1 for. The D / A converter 21 acquires a display signal stored in the shift register 22 simultaneously for one row of pixels at the timing at which the load pulse 1 is input, and performs a D / A conversion to obtain a voltage corresponding to each display signal. The signal is output to the signal line of the liquid crystal display panel 10.

In addition, the timing controller 32 of the controller 13 applies the load pulse 2 to the D / A converter 21 of the source driver 11 at the timing of inserting the black display for preventing reverse transition within the 1H period. Output The D / A converter 21 acquires black display data stored in the black display register 23 at the same time for one row of pixels at the timing at which the load pulse 2 is input, and performs D / A conversion to correspond to the black gray level. The voltage is output to the signal line of the liquid crystal display panel 10.

As described above, in the liquid crystal display device shown in FIG. 1, the black display data is transferred to the black display register 23 in the blanking period, whereas in the liquid crystal display device shown in FIG. 3, the input of the video signal is related. The difference is that the black display data is transferred to the black display register 23 when the power supply is turned on. Since the black display data is transmitted only once when the power is turned on, it is necessary to perform timing control of the timing of transferring the display data to the shift register 22 and the timing of transferring the black display data to the black display register 23. Since it does not exist, timing control can be performed easily.

In any of the liquid crystal display devices of this first embodiment of Figs. 1 and 3, the black display data of each pixel with respect to the inserted black display is the same, so that the black display data of the pixel number less than one line is used for the black display register. The black display data may be stored in (23), and the black display data may be repeatedly used as black display data for inserting another pixel. In this case, therefore, if the black display register 23 can store at least one pixel of black display data, it is possible to cope with the reversal prevention method by black insertion of the first embodiment.

In addition, since the gradation information of the black display data stored in the black gradation storage unit 33 can be set individually for each gradation of R, G, and B, the liquid crystal display panel ( The tone information of the black display data for black insertion can be set in accordance with the characteristic of 10).

(2nd Example)

4 is a block diagram showing the configuration of a liquid crystal display device according to a second embodiment of the present invention.

The liquid crystal display device of the second embodiment has a black data storage section 24 instead of the black driver register 23 having the source driver 11 of the first embodiment shown in FIGS. 1 and 3. This point differs from the first embodiment.

The black data storage section 24 is a ROM in which black display data for black insertion for one row of pixels is stored in advance. The other configuration is the same as that of the liquid crystal display device of the first embodiment shown in FIG. 1, and thus description thereof is omitted. The black data storage section 24 corresponds to an example of the second data storage section in which the second data of the present invention is stored in advance.

FIG. 5 shows a timing chart showing the flow of display data when performing the inversion prevention driving in which black display is inserted in the liquid crystal display of the second embodiment shown in FIG.

Hereinafter, the reverse transition prevention driving operation in the liquid crystal display device of the second embodiment will be described with reference to FIGS. 4 and 5.

When the video signal of the RGB data is input to the signal processing unit 35 of the controller 13, the signal processing unit 35 performs gradation correction or gamma correction processing on the input video signal.

The timing controller 32 of the controller 13 outputs a start pulse 1 at a timing at which the respective display signals S1 to S4 included in the video signal are started to be input, thereby outputting the display signal processed by the signal processing unit 35. The transfer to the shift register 22 is started. Here, the display signal processed by the signal processing unit 35 is sequentially transmitted to the shift register 22 without performing double-speed conversion processing. Therefore, the display signal is transmitted from the signal processing unit 35 to the shift register 22 at the same speed (1x speed) as the video signal input to the controller 13. The timing at which the timing controller 32 outputs the start pulse 1 is the same timing as the timing at which the timing controller 32 outputs the start pulse 1 in the first embodiment.

In addition, the process which the timing control part 32 outputs the start pulse 1, and starts to transmit a display signal to the shift register 22 is an example of the video data input timing control step of this invention.

Next, the timing control part 32 of the controller 13 has the D / A conversion part 21 of the source driver 11 before the timing which outputs the start pulse 1 which starts the transmission of the next display signal contained in a video signal. Outputs the load pulse 1 for. The D / A converter 21 acquires a display signal stored in the shift register 22 simultaneously for one row of pixels at the timing at which the load pulse 1 is input, and performs a D / A conversion to obtain a voltage corresponding to each display signal. The signal is output to the signal line of the liquid crystal display panel 10.

In addition, the timing controller 32 of the controller 13 applies the load pulse 2 to the D / A converter 21 of the source driver 11 at the timing of inserting the black display for preventing reverse transition within the 1H period. Output The D / A converter 21 acquires black display data for one row of pixels stored in the black data storage unit 24 in advance at the timing at which the load pulse 2 is input, performs D / A conversion, and performs black gradation. Is output to the signal line of the liquid crystal display panel 10. The timing at which the timing controller 32 outputs the load pulse 1 and the load pulse 2 is the same timing as the timing at which the timing controller 32 outputs the load pulse 1 and the load pulse 2 in the first embodiment.

In addition, the process which the timing control part 32 outputs the load pulse 1 and the load pulse 2, and controls the D / A conversion part 21 is an example of the output timing control step of this invention.

In this manner, as shown in FIG. 5, black display data is inserted and output between the display signals from the source driver 11 to the liquid crystal display panel 10.

As shown in FIG. 5, the load pulse 1 is output at the timing immediately before the next display signal is input. Therefore, the timing output from the source driver 11 to the signal line of the liquid crystal display panel 10 is determined by the controller 13. It is output at a timing delayed by 1H period with respect to the video signal inputted to.

Since the black insertion period is determined by the output timing of the load pulse 2, the ratio of the black insertion period to the display period can be adjusted by changing the output timing of the load pulse 2. Faster output timing of load pulse 2 in the 1H period increases the ratio of the black insertion period, and slower decreases the ratio of the black insertion period.

In the second embodiment, the black data storage unit 24 stores black display data for black insertion for one row of pixels. However, the black display data of each pixel for the black display to be inserted is Since it is the same, black display data of less than one line of pixels may be stored in the black data storage 24 in advance, and the black display data may be repeatedly used. Therefore, in this case, the black data storage unit 24 can respond if at least one pixel of black display data is stored in advance.

In addition, in the second embodiment, the black data storage unit 24 is a ROM, but other elements may be used as long as it can only acquire pre-stored black display data corresponding to the inserted black display. For example, it may be implemented in a hard configuration such as a circuit configuration in which the value of the black display data is fixedly output.

As described above, when the liquid crystal display device of the present invention and the display data control method thereof are used, in the conventional reverse transition prevention driving by double speed conversion, the display signal is transferred from the controller to the source driver at high speed (double speed). Compared to the above, the transmission can be performed at a low speed (1x speed), so that power consumption of the controller and the source driver can be reduced. In addition, the conventional high frequency noise problem caused by the high speed transmission between the controller and the source driver does not occur.

In addition, since there is no need to install the line memory required in the conventional double reverse conversion preventing drive, it is possible to cope only with the addition of the black insertion data storage unit that can cope with a slight change in the circuit configuration, thereby reducing the cost. Can be. In addition, since it is not necessary to perform the high speed processing of double speed conversion, it is not necessary to use a high performance element for a controller, and the cost can be reduced also in this point.

Moreover, although each Example demonstrated the case where black data for black insertion for reverse transition prevention was displayed in the liquid crystal display panel using the liquid crystal display element of OCB mode, the liquid crystal display device of such a structure, and its control was demonstrated. The method is also applicable to the case of inserting black data for improving moving image visibility. Not only the liquid crystal panel using the liquid crystal display element of the OCB mode but also the liquid crystal panel using other liquid crystal display elements, the black data for the improvement of moving image visibility by the structure demonstrated in each Example like FIG. 1, FIG. 3, FIG. Can be inserted.

In the case where black data is inserted for the improvement of moving picture visibility, moving picture visibility is improved by increasing the ratio of the black insertion period for displaying black data to the display period for displaying the display data.

In addition, as the black data described in each embodiment, not only data of one type of video gray level corresponding to black of video display, but also data of a plurality of types of predetermined video gray levels may be provided. When the insertion rate of black data is increased, moving image visibility is improved, but luminance is lowered accordingly. For example, when displaying a still image, it is possible to make the brightness brighter by inserting data of other video gradations instead of the black data to be inserted. That is, by providing the data of a plurality of video gradations as data to be inserted into the display data, and changing the video gradation of the data to be inserted as necessary, it becomes possible to display appropriate to the situation.

Further, the program of the present invention according to the present invention, in the video display period of the display data control method of the liquid crystal display device of the present invention described above, performs D / A conversion on the video data stored in the shift register to the signal line. The output timing for supplying the first voltage and controlling timing to supply the second voltage to the signal line by performing D / A conversion on the second data stored in the second data storage unit in the predetermined period. As a program for executing the operation of the control step by the computer, the program operates in cooperation with the computer.

Further, the recording medium of the present invention, in the video display period of the display data control method of the liquid crystal display device of the present invention described above, performs D / A conversion of the video data stored in the shift register to the first signal line. In the output timing control step of supplying a voltage and controlling timing to supply the second voltage to the signal line by performing D / A conversion on the second data stored in the second data storage section. A recording medium on which a program for executing an operation by a computer is recorded, the recording medium being readable by the computer, and the read program being used in cooperation with the computer.

In addition, one use mode of the program of the present invention according to the present invention may be a mode that is recorded in a computer-readable recording medium and operates in cooperation with the computer.

The recording medium also includes a ROM and the like.

The computer of the present invention described above is not limited to pure hardware such as a CPU, but may include a firmware, an OS, and a peripheral device.

As described above, the configuration of the present invention may be implemented in software or in hardware.

Industrial availability

Since the liquid crystal display device, the display data control method, etc. which concern on this invention can reduce power consumption, it is useful for the liquid crystal display device using liquid crystals, such as an OCB mode liquid crystal, its display data control method, etc.

According to the present invention, it is possible to provide a liquid crystal display device, a display data control method thereof, and the like, which can reduce power consumption.

Claims (14)

A liquid crystal display panel having signal lines and scanning lines arranged in a matrix, and pixel electrodes formed corresponding to intersections of the signal lines and the scanning lines; A gate driver for supplying a gate signal to the scan line; A second register in which image data for display in the image display period is sequentially inputted for one row of pixels, and simultaneously outputs one row of pixels; and a second stored second data independent of the image data applied to the respective pixel electrodes. A source driver having a data storage section and a D / A converter section for supplying a voltage to the signal line by performing D / A conversion on the video data acquired from the shift register and the second data acquired from the second data storage section; , A first timing for inputting the video data included in the input video signal to the shift register, wherein the D / A converter is configured to acquire the video data from the shift register and perform D / A conversion to supply voltage to the signal line; A timing control unit configured to control a second timing and a third timing in which the D / A converter acquires the second data from the second data storage unit, performs D / A conversion, and supplies a voltage to the signal line. Liquid crystal display device provided with. The method of claim 1, And the second data is data for displaying at least one kind or more of predetermined video gradations. The method of claim 1, The second data is black data for displaying in a black insertion period in a normally white mode. The method of claim 3, wherein The liquid crystal used for the said liquid crystal display panel is an OCB mode liquid crystal, The liquid crystal display device. The method of claim 1, Further comprising a second data generating unit for generating the second data, And the timing controller controls to input the second data generated by the second data generator to the second data storage unit in a blanking period of the input video signal. The method of claim 5, And the second data generation unit generates the second data from grayscale data of R, G, and B individually set. The method of claim 1, And a second data generator for generating the second data and inputting the second data to the second data storage unit regardless of the input of the video signal when the power is turned on. The method of claim 7, wherein And the second data generation unit generates the second data from grayscale data of R, G, and B individually set. The method of claim 1, The second data of the second data storage unit is stored in advance. A liquid crystal display panel having a signal line and a scan line arranged in a matrix shape, and a pixel electrode formed corresponding to the intersection of the signal line and the scan line, a gate driver for supplying a gate signal to the scan line, and a signal line during the video display period. A source driver for supplying a first voltage corresponding to the gray level of the image data and supplying a second voltage corresponding to the gray level of the second data independent of the image data to the signal line in a predetermined period not including the video display period. A display data control method of a liquid crystal display device having a Inputting the image data included in the input image signal to a shift register of the source driver, which sequentially inputs the image data for display in the image display period and outputs one row of pixels at the same time A video data input timing control step of controlling timing; In the video display period, the video data stored in the shift register is D / A-converted to supply the first voltage to the signal line, and in the predetermined period, it is stored in a second data storage part of the source driver. An output timing control step of controlling timing so as to D / A-convert second data to supply the second voltage to the signal line Display data control method of the liquid crystal display comprising a. The method of claim 10, And the second data is data for displaying at least one or more types of predetermined video gray scales. The method of claim 10, And the second data is black data for display in a black insertion period in a normally white mode. The method of claim 12, The liquid crystal used for the said liquid crystal display panel is an OCB mode liquid crystal, The display data control method of the liquid crystal display device. In the video display period of the display data control method of the liquid crystal display device of claim 10, the video data stored in the shift register is subjected to D / A conversion to supply the first voltage to the signal line. A program for operating a computer to execute the output timing control step of controlling timing to D / A-convert the second data stored in the second data storage section to supply the second voltage to the signal line. Recording media.

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