JP2006267357A - Liquid crystal driving device and liquid crystal driving method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device and a liquid crystal display method which have good visual responsiveness to changes of display images in moving image display and display images of high quality. <P>SOLUTION: The liquid crystal display device includes: a liquid crystal panel which has a plurality of scan lines extending in a plurality of row directions; a plurality of data lines extending in a plurality of column directions, and a plurality of pixels provided correspondingly to intersections between the scan lines and the data lines; a data line driving circuit for giving display data to the data lines; a scan line driving circuit for giving scan signals to the scan lines; a light source provided for each of blocks into which the plurality of scan lines of the liquid crystal panel are divided: a light source control means for controlling lighting of light sources per block in accordance with application timings of the scan signals to respective scan lines; and a signal correction means for correcting display data applied to pixels corresponding to respective scan lines in accordance with a scan sequence of scan lines in blocks. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid crystal driving apparatus and method for illuminating a liquid crystal panel with a light source and displaying an image on the surface of the liquid crystal panel, and more particularly to a liquid crystal driving apparatus and method for performing drive control as a response type display for driving a light source to turn on.

In recent years, flat panel displays such as liquid crystal display devices (LCD) have been widely used as display devices for computer CRTs and televisions.
However, since the liquid crystal display device has a characteristic that the liquid crystal element retains the data state until it is rewritten, the spatial frequency characteristic is lowered and suitable for displaying still images such as characters. However, there is a drawback that the contour of the changing image is perceived in a blurred state.

For this reason, in the liquid crystal display device, a plurality of scanning lines of the liquid crystal panel are used as blocks, and a backlight corresponding to these blocks is sequentially turned on by pulse driving corresponding to the scanning of the scanning lines as shown in FIG. A method of reducing the blurring of the outline when displaying a moving image by realizing a response type (impulse type) display method is used (for example, see Patent Document 1). Here, in the liquid crystal display circuit having the configuration shown in FIG. 16A, a plurality of scanning lines extending in a plurality of row directions are provided at positions where data lines extending in a plurality of column directions intersect. For a liquid crystal panel having pixels (liquid crystal display elements), a signal driver outputs display data corresponding to each pixel to each data line, and the scan driver 100 sequentially scans the scan lines in the Y direction, Control is performed so that display data is applied to the pixels.
Also, as shown in FIG. 16B, for example, the scanning lines Y1 to Y4 correspond to the backlight block A, the scanning lines Y5 to Y8 correspond to the backlight block B, and each scanning line receives light. The scanning is controlled by dividing the block corresponding to the block of the backlight to be irradiated.
The drive control circuit in FIG. 16A includes a timing signal generation circuit, a clock generation circuit, a data conversion circuit (signal correction circuit), and the like in order to control the drive timing of the data line and the scanning line.
Further, in the liquid crystal display device, when the backlight illuminates all the scanning lines at once, the backlight has a predetermined time width at the timing when the liquid crystal element of the scanning line that is scanned latest becomes saturated. There is also a method of lighting (see, for example, Patent Document 2).
JP 2004-62134 A JP 2004-93717 A

However, in the liquid crystal display device disclosed in Patent Document 1, as shown in FIG. 16A, the operation line timing signal sequentially output from the scanning line driving circuit 100 in the order of Y1 → Yn in synchronization with the clock. Each of the scanning lines A-1 to A-n is scanned in units of one line by Y1 to Yn, and similarly, the liquid crystal elements corresponding to the display data D1 to Dm output from the data line driving circuit 101 in synchronization with the clock. 102 is written. On the other hand, as shown in FIG. 16B, the backlight is divided and controlled in units of blocks and irradiates a plurality of scanning lines at once. For example, when the scanning lines A-1 to A-4 correspond to the block A in which the backlight is divided, the backlight of the block A is placed at a predetermined position in the period during which the scanning line timing signals Y1 to Y4 are output. Light.
For this reason, as shown in FIG. 17, there is a problem that image degradation occurs due to a timing shift between the response of the liquid crystal element 102 and the lighting of the light source driven in units of blocks. For example, the scanning lines A-1 to A-4 are scanned by the scanning line timing signals Y1 to Y4 corresponding to the backlight block A, and the scanning line A-1 that is scanned first in the same block A in the same frame is scanned. Compared to the above, the scanning timing of the scanning line A-4 to be driven last is delayed by the time Td. For this reason, when the backlight irradiates the liquid crystal panel with the driving pulse PA (pulse width Tp), assuming that the display data (for example, gradation) applied to each pixel is the same numerical value, the scanning line in the liquid crystal panel The amount of light transmitted through the pixel corresponding to A-1 is different from the amount of light transmitted through the pixel of the liquid crystal element 102 corresponding to the scanning line A-4, and image degradation occurs.
Here, the liquid crystal display device disclosed in Patent Document 1 describes a method of suppressing image quality degradation by degrading image quality deterioration by controlling the lighting of the backlight so that it corresponds to driving of the scanning line. Even if it is controlled in units, since it corresponds to a plurality of scanning lines, there is essentially a problem of a difference between the backlight and the scanning timing. Further, when scanning processing is performed in units of one scanning line, the backlight control circuit There is a drawback that it becomes large and the apparatus becomes expensive.

Further, in the liquid crystal display device disclosed in Patent Document 2, if sufficient luminance is obtained with a predetermined light source, a region in which all scanning lines are completely saturated is limited and the lighting time is shortened. It is difficult to perform the blinking operation of the light source at the timing when the scanning line is completely saturated, and there is a problem that only low precision control can be performed.
Here, in the liquid crystal display device disclosed in Patent Document 2, in order to widen a saturated region, precharge data representing a plurality of pixels is generated, and first writing is performed on all pixels using the precharge data. In addition, overwrite data for actual gradation is added to each pixel to perform a process of apparently improving the response of the liquid crystal. However, although the correction processing in the liquid crystal display device is effective for the representative pixel to be corrected, it does not become effective correction for all the pixels, and there is a problem in the accuracy of correction.

  The present invention has been made in view of such circumstances, and provides a liquid crystal display device and a liquid crystal display method that display a high-quality image that is visually responsive to changes in the display image in moving image display. The purpose is to provide.

The liquid crystal display device of the present invention is provided corresponding to a plurality of scanning lines extending in a plurality of row directions, a plurality of data lines extending in a plurality of column directions, and an intersection of the scanning lines and the data lines. A liquid crystal panel having a plurality of pixels, a data line driving circuit for giving display data to the data lines,
A scanning line driving circuit for supplying a scanning signal to the scanning line, a light source provided corresponding to each block obtained by dividing the plurality of scanning lines of the liquid crystal panel, and the scanning signal applied to each scanning line The light source control means for controlling the lighting of the light source for each of the blocks in correspondence with the timing, and the pixels corresponding to the scanning lines corresponding to the scanning order of the scanning lines in the block Signal correction means for correcting the display data applied to the display.
The liquid crystal display method of the present invention is provided corresponding to a plurality of scanning lines extending in a plurality of row directions, a plurality of data lines extending in a plurality of column directions, and an intersection of the scanning lines and the data lines. A liquid crystal panel having a plurality of pixels, a data line driving circuit for supplying display data to the data lines, and a scanning line driving circuit for supplying scanning signals to the scanning lines. A light source control process for controlling lighting of a light source provided corresponding to each block obtained by dividing the scanning line of the liquid crystal panel in accordance with a timing at which the scanning signal is applied to the scanning line; And a signal correction process for correcting the display data applied to the pixels corresponding to the scanning lines in correspondence with the scanning order of the scanning lines.
As a result, the liquid crystal display device of the present invention can control the response of the liquid crystal elements between the scanning lines in the block and the lighting of the driven light source when displaying a moving image by controlling the lighting of the backlight in units of blocks. The variation in the relative amount of light transmitted through the liquid crystal panel between the pixels corresponding to the scanning line due to the timing difference in the above can be corrected for each scanning line corresponding to the relative position in the block, Degradation of the display image of each scanning line can be suppressed with high accuracy.

The liquid crystal display device of the present invention has a correction table indicating a correction amount (correction data) corresponding to the scanning order of the signal correction means, reads the correction amount corresponding to each scanning line, and performs the correction The display data is corrected by the amount.
As a result, the liquid crystal display device of the present invention eliminates the need to perform the calculation of the correction amount itself each time, simplifies the calculation of the correction amount and the calculation circuit, and scans the light amount correction processing of each pixel of each scanning line. It becomes possible to correspond to the scanning speed of the line.

The liquid crystal display device of the present invention is characterized in that the signal correction means corrects the display data in response to a change in display data applied between frames.
As a result, the liquid crystal display device of the present invention has a combination of the gradation of the display data of the pixel of the frame to be displayed and the gradation of the display data of the pixel of the immediately preceding frame, that is, the scale of the display data before and after the change. Corresponding to the combination of the furniture, the display data after the change is corrected (displayed), and the transient state (response speed) of the change in the transmittance of the liquid crystal element due to the change in the gradation of the display data indicates the scale of the display data. It is possible to improve the phenomenon that varies depending on the combination of the furniture, and it is possible to suppress image deterioration of the display image.

In the liquid crystal display device of the present invention, the signal correction unit has a correction table indicating a correction amount corresponding to a difference in display data applied between frames, reads out the correction amount corresponding to the difference, and based on the correction amount The display data is corrected.
As a result, the liquid crystal display device of the present invention eliminates the need for calculation of the correction amount itself each time, simplifies the calculation of the correction amount and the calculation circuit, and corrects the response speed of each liquid crystal element of each scanning line. Can correspond to the scanning speed of the scanning line.

The liquid crystal display device of the present invention is characterized in that it has a light amount adjusting means for adjusting the amount of light emitted from the light source corresponding to the scanning order in the block.
The liquid crystal display device according to the present invention is characterized in that the light amount adjusting means adjusts the light amount emitted from the light source corresponding to the scanning order of the scanning lines in the block.
The liquid crystal display device according to the present invention is characterized in that the light amount adjusting means controls the lighting time of the light source corresponding to the scanning order of the scanning lines in the block.
As a result, the liquid crystal display device of the present invention can control the response of the liquid crystal elements between the scanning lines in the block and the lighting of the driven light source when displaying a moving image by controlling the lighting of the backlight in units of blocks. Variations in the relative amount of light transmitted through the liquid crystal panel between the scanning lines due to the timing difference between the scanning lines can be corrected according to the relative position in the block, and deterioration of the display image of each scanning line is suppressed. can do.

In the liquid crystal display device of the present invention, the light amount adjusting means is provided so as to face the liquid crystal panel with the light source interposed therebetween, and has a structure that reflects light of a light amount corresponding to the scanning order of each scanning line. It is a board.
As a result, the liquid crystal display device of the present invention can control the response of the liquid crystal elements between the scanning lines in the block and the lighting of the driven light source when displaying a moving image by controlling the lighting of the backlight in units of blocks. Variations in the relative amount of light transmitted through the liquid crystal panel between scanning lines due to the timing difference between the scanning lines can be corrected according to the relative position in the block without using complicated circuit processing. Deterioration of the display image of the line can be suppressed.

The liquid crystal display device of the present invention is provided corresponding to a plurality of scanning lines extending in a plurality of row directions, a plurality of data lines extending in a plurality of column directions, and an intersection of the scanning lines and the data lines. A liquid crystal panel having a plurality of pixels, a data line driving circuit for supplying display data to the data lines, a scanning line driving circuit for supplying scanning signals to the scanning lines, and a plurality of the scanning lines of the liquid crystal panel. A light source provided corresponding to each of the divided blocks, a light source control unit that controls lighting of the light source for each block in correspondence with a timing at which the scanning signal is applied to the scanning line, and the block And an irradiation light amount adjusting means for adjusting the amount of light emitted from the light source corresponding to the scanning order of the scanning lines.
As a result, the liquid crystal display device of the present invention can control the response of the liquid crystal elements between the scanning lines in the block and the lighting of the driven light source when displaying a moving image by controlling the lighting of the backlight in units of blocks. The variation in the relative amount of light transmitted through the liquid crystal panel between the pixels corresponding to the scanning line due to the timing difference in the above can be corrected for each scanning line corresponding to the relative position in the block, Degradation of the display image of each scanning line can be suppressed with high accuracy.

<First Embodiment>
A liquid crystal display device according to a first embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a conceptual diagram showing a configuration example of the liquid crystal panel of the embodiment. FIG. 1A is a conceptual diagram showing a configuration example of a liquid crystal display device, and a plurality of scanning lines A-1, A-2, A-3, A-4 in which the liquid crystal panel 3 extends in the row direction. , A-5,... And data lines L1 to Lm extending in the column direction, and pixels (liquid crystal elements) are formed at the intersections of the scanning lines and the data lines. Here, each of the scanning lines A-1 to An is scanned in units of one line by the operation line timing signals Y1 to Yn sequentially output from the scanning line driving circuit 100 in order of Y1 → Yn in synchronization with the clock. Similarly, the display data D1 to Dm output from the data line driving circuit 101 in synchronization with the clock are written in the corresponding liquid crystal elements 102.
FIG. 1B is a conceptual view of the backlight mechanism including the reflecting plate as viewed from the side, and shows that the light source of the backlight is divided into a plurality of blocks A, B, C,. . The scanning lines are grouped every predetermined number, and this group corresponds to the block. For example, in each block, when five scanning lines and three light sources in the backlight are configured to correspond to each other, the scanning lines A-1 to A-5 of the set of the block A are light sources BA-1 to BA-3. Is irradiated with light. Here, each scanning line of the liquid crystal panel is scanned in the Y direction (from the upper end to the lower end).

Next, a drive circuit portion of the liquid crystal display device according to the first embodiment of the present invention will be described with reference to FIG. FIG. 2 is a block diagram illustrating a configuration example of the liquid crystal display device according to the first embodiment of the present invention.
In this figure, the light quantity correction unit 1 corrects the input display data of each pixel for each scanning line according to the relative position of each scanning line in the block, that is, the order of the scanning lines to be scanned. Although details will be described later, as described in the conventional example, as the scanning order is later, the transmittance of the liquid crystal element becomes insufficient due to the response delay of the liquid crystal element with respect to the actual gradation, and the display panel The amount of light that passes through the light decreases compared to the previously scanned scan line. Therefore, in order to make the amount of light transmitted through the liquid crystal elements of each scanning line in the block relatively correspond to the display data, the display data (for example, the floor) of each pixel of the scanning line is changed as the scanning order becomes later in the block. Correction to increase the furniture) by a predetermined amount.

The liquid crystal driving unit 2 includes the scanning line driving circuit 100 and the data line driving circuit, and the scanning line driving circuit 100 displays each scanning line of the liquid crystal panel 3 (see FIG. 1A) as shown in FIG. Scanning is performed one line at a time from the upper part to the lower part of a), and the data line driving circuit 101 outputs display data to each data line, that is, the display data is written in parallel to each pixel of the scanning line.
In the backlight 5 (see FIG. 1B), the backlight control unit 4 associates each of the divided blocks with a count-up signal output from a counter unit 7 to be described later. In this order, lighting is performed with a lighting pulse having a predetermined width. For example, as shown in the timing chart of FIG. 3, the backlight control unit 4 outputs a lighting pulse PA corresponding to the frame synchronization signal and inputs a count-up signal from the counter unit 7 as the lighting timing of each block. .., PB, PC,... Are output sequentially, and the light sources of the blocks A, B, C,... Are turned on for a time corresponding to the pulse width. The state is initialized by the frame synchronization signal input every time the frame is changed, and the lighting pulse PA is output.

Here, FIG. 3A shows that the backlight control unit 4 turns on the light source in the backlight 5 for each block, and controls so that the lighted state does not overlap between the blocks. On the other hand, in FIG. 3B, the backlight control unit 4 turns on the corresponding light source for each block, but it is turned on for the purpose of substantially increasing the amount of light compared to the control of FIG. It is shown that control is performed so that the overlapped state overlaps between adjacent blocks. Here, the light source includes a cold cathode tube, an LED (Light Emitting Diode), an EL (Electroluminescent) element, and the like.
In addition, the control unit 6 outputs a scanning timing signal to the counter unit 7 every time a scanning signal is output to each scanning line in synchronization with the scanning signal output to each scanning line in the liquid crystal panel 3.
When the counter unit 7 counts the scanning signal and reaches the number of scanning lines in the block, the counter unit 7 starts a new count from the next count, and uses the count value as scanning order data for each scanning line in each block. 1 and outputs a count-up signal to the backlight control unit 4 every time it counts up.

Next, the configuration of the light quantity correction unit 1 in FIG. 2 will be described in detail with reference to FIG. FIG. 4 is a block diagram showing a configuration example of the light amount correction unit 1 according to the first embodiment of the present invention.
In this figure, when the above-mentioned scanning order data indicating the relative position in the scanning line block, that is, the scanning order is input, the first correction unit 10 corresponds to the scanning order data from the position correspondence correction table 11. The correction data for the display data of the pixels of the scanned line is read out. The first correction unit 10 corrects the display data of the pixels with the correction data. This correction data is, for example, an addition correction value, which is set for each numerical value (for example, gradation) of display data, and performs correction by simply adding to display data of a pixel that is input, A correction coefficient that can be corrected by multiplying the display data of the pixel.
In the position correspondence correction table 11, as described above, the relative position of each scanning line in the block, that is, the scanning order of the scanning lines (in the case of an addition correction value, the combination of display data is also included), and the scanning order. Scanning line correction data is stored correspondingly.

Next, the operation of the first embodiment will be described with reference to FIGS. 1, 2, 3 (a), 4 and 5. FIG. 5 is a waveform diagram showing the scanning signal, the lighting pulse for turning on the light source in units of blocks, and the transmittance of the pixels corresponding to the scanning lines. In the following description, it is assumed that the correction data stored in the position correspondence correction table 11 is an addition correction value.
When the control unit 6 outputs a frame synchronization signal, display data for pixels on the scanning line A-1 is sequentially input from an image processing circuit (not shown), and the count value of the counter unit 7 is reset to “0”.
Then, the control unit 6 outputs a scanning timing signal corresponding to the scanning signal Y1 output to the scanning line A-1 to the counter unit 7. As a result, the counter unit 7 increments the count value, that is, increases “1” from “0” to “1”.

At this time, the light quantity correction unit 1 receives the scan order data (count value “1”) input from the counter unit 7, but does not perform any correction processing when the count value is “1”. That is, for each pixel of the scanning line A-1 that is scanned first in the block A, the scanning line A-1 is used as a reference for correction, so that correction is not performed and the pixel is directly output to the liquid crystal driving unit 2. .
Next, the liquid crystal drive unit 2 outputs the scanning signal Y1 to the scanning line A-1 in synchronization with the clock (time tA1) from the control unit 6, and displays the display data D1 to Dm on the data lines L1 to Lm, respectively. By outputting, corresponding display data is written in parallel to the liquid crystal element of each pixel of the scanning line A-1.

Then, display data is written to each pixel of the scanning line A-1 of the liquid crystal driving unit 2 (timing when scanning of the scanning line A-1 is completed), for example, the next scanning is performed by a writing signal of the scanning line A-1. Input of display data to be written to each pixel of the line A-2 is started.
At this time, the control unit 6 outputs a scanning timing signal corresponding to the scanning signal Y2 output to the scanning line A-2 to the counter unit 7. Accordingly, the counter unit 7 increments the count value, that is, increases “1” to “1” to “2”.
When the count value “2” is input to the light amount correction unit 1 as the scan order data, the first correction unit 10 reads the count value “2” and the display data of each pixel from the position correspondence correction table 11. The addition correction value is read out by the numerical value of the above, and the addition correction value is added to the display data of each pixel to correct the display data of each pixel, and the display data of the corrected pixels is sequentially transferred to the liquid crystal drive unit 2. Output.

  Next, the liquid crystal driving unit 2 outputs a scanning signal Y2 to the scanning line A-2 in synchronization with the clock (time tA2) from the control unit 6, and displays the display data D1 to Dm on the data lines L1 to Lm, respectively. By outputting, corresponding display data is written in parallel to the liquid crystal element of each pixel of the scanning line A-2. Thereby, each pixel of the scanning line A-2 is corrected to display data to which the count value “2” and the addition correction value S2 corresponding to the gradation are added. Therefore, when the display data has the same numerical value, the amount of light transmitted from the scanning line A-2 is adjusted to be equal to the amount of light transmitted through the scanning line A-1.

Then, the backlight control unit 4 responds to, for example, a scanning signal output to any scanning line in the block A, and the light sources BA-1, BA-2, BA- of the block A in the backlight 5. A pulse PA for driving 3 is output, and each of the light sources BA-1, BA-2, BA-3 is turned on. The timing at which this pulse PA is output does not have to be after all have reached saturation as in the conventional example, and can be set with more flexibility, for example, in accordance with the output timing of one of the scanning signals. it can.
In FIG. 6, the curves A-1, A-2,..., A-4 are written in the liquid crystal elements of the scanning lines A-1, A-2,. A change in light transmittance corresponding to the gradation of each display data is shown, and PA is a lighting pulse for turning on the light source of the block A. Further, the curves B-1, B-2,..., B-4 indicate the gradations written in the liquid crystal elements of the horizontal lines B-1, B-2,. The corresponding light transmittance change is shown, and PB is a lighting pulse for lighting the light source of the block B. Similarly, the curves C-1, C-2,..., C-4 indicate the gradations written in the liquid crystal elements of the horizontal lines C-1, C-2,. , Pc is a lighting pulse for turning on the light source of block C.
In each block of the liquid crystal element, the display data is applied, i.e., the display data of the scanning line with the timing when the scanning signal is applied is set to be gradually higher in the display order, so that the light source is turned on. The time for having sufficient transmittance for each scanning line (time for obtaining sufficient luminance) becomes longer. For example, as shown in FIG. 6, the numerical value of the display data of A-2 is higher by S2 than that of A-1, and the numerical value of the display data of A-4 is higher by S4 than by A-2. As a result, the area defined by the transmittance curves A-1 to A-4 corresponding to the pulse PA becomes larger than that in the case where correction is not performed.

The correction processing for the display data of each pixel for the scanning line A-2 is similarly performed for the scanning lines A-3 and A-4. At this time, the control unit 6 outputs the scanning signal Y4 to the liquid crystal driving unit 2 in synchronization with the clock (time tA4) for the scanning line A-4, and after scanning the scanning line A-4, A scanning signal for the scanning line B-1 of the block B is output.
Accordingly, the counter unit 7 sets the count value from “4” to “1”, and repeats the display data correction operation similar to that for the block A for the block B (time tB1 to tB4). Thereafter, the same processing is performed for the blocks C (time tC1 to tC5), D,. Also, the same processing as that for the first frame is performed for the second frame.
By the processing in the first embodiment described above, the display data applied to the sequentially driven scanning lines is gradually set higher in the display order so that the area defined by each transmittance curve is corrected. The amount of light radiated from the light source can be substantially the amount of light corresponding to each display data, and the relative amount of light transmitted through the liquid crystal panel between the scanning lines can be increased. The variation can be corrected corresponding to the relative position in the block, and deterioration of the display image of each scanning line can be suppressed.

<Second Embodiment>
Next, a liquid crystal display device according to a second embodiment of the present invention will be described with reference to the drawings. The configuration of the second liquid crystal display device is the same as that of the first embodiment in FIGS. 1 and 2, and the configuration of the light quantity correction unit 1 shown in FIG. 4 is different. Hereinafter, with reference to FIG. 7, the difference of the liquid crystal display device of the second embodiment from the first embodiment will be described. FIG. 7 is a block diagram illustrating a configuration example of the light amount correction unit 1 illustrated in FIG. 2 according to the second embodiment. The configuration added to the first embodiment is a second correction unit 12, a response speed correction table 13, a storage unit 14, and a correction control unit 15, which will be described in order below.

  The second correction unit 12 controls the amount of light by adjusting the display data of each pixel in response to the numerical change of the display data between the frames of each pixel. In other words, the second correction unit 12 adjusts the response speed of the liquid crystal element so as to obtain a transmittance corresponding to the written display data. Therefore, the change in the display data of the corresponding pixels between the frame to be displayed and the immediately preceding frame. That is, the gradation level to be displayed is corrected for each liquid crystal element based on the combination of the immediately preceding display data and the display data to be corrected. The storage unit 4 stores display data corresponding to all pixels (liquid crystal elements) of the liquid crystal panel in the immediately preceding frame.

The response speed correction table 13 stores speed correction data corresponding to a combination of changes from the display data G to the display data R. The speed correction data may also be any of the already described addition correction value and correction coefficient.
When the display data after correction is input from the first correction unit, the correction control unit 15 further corrects the corrected display data with the speed correction data. At this time, if the speed correction data is the addition correction value, the correction control unit 15 simply adds the addition correction value to the display data from the first correction unit 15, while if the speed correction data is the correction coefficient. The display data from the first correction unit 15 is multiplied by a correction coefficient. Thereby, the correction control unit 15 performs light amount adjustment with higher accuracy in order to improve the response speed of the liquid crystal element.
For example, if the value of the display data to be displayed is lower than the value of the display data before the change, the display data value to be displayed is set to be lower in consideration of the response speed of the liquid crystal. If the numerical value of the display data to be displayed is higher than the numerical value of the display data before the change, the numerical value of the display data to be displayed is set to be higher.

  The response speed correction table 13 stores the correspondence between the display data combination before and after the change and the speed correction data with respect to the change from the gradation A as the display data to the gradation B. Yes. At this time, if changing combinations are prepared for the numerical values of all display data, the number of combinations increases and the amount of data increases. For this reason, the numerical value of the display data may be divided into a plurality of blocks and stored as a combination of changes between the blocks. For example, when the display data gradation is 256 gradations, as shown in FIG. 8, pixels to be corrected with the gradations 1 to 32 as blocks H1, 33 to 64 as blocks H2,... 225 to 256 as blocks H8. As a change from the block H1 to H7 and the change from the block H6 to H2 including the display data, the combination of blocks corresponding to the display data before and after the change to the response speed correction table 13; The correspondence with the speed correction data may be stored. In FIG. 8, for example, the display data before the change belongs to the block H1, and the display data after the change (to be displayed from now on) corresponds to the display data combination “H1 → H2” of the block H2, and the speed correction data. D12 is stored.

Further, in synchronization with the scanning signal, the liquid crystal driving unit 2 once resets each liquid crystal element of the corresponding scanning line to the gradation “1” as the display data, that is, the gradation “1” (black data in FIG. 5). In the next frame, display data may be written to the liquid crystal elements of each scanning line in the next frame.
By doing so, the display data always changes from the display data of the gradation degree “1” to the display data of the predetermined gradation degree. As described above, when the gradation degree is divided into eight blocks, as a combination of changes, Only eight types are available, and the response speed correction table 13 can be formed very compactly.

<Third Embodiment>
Next, a liquid crystal display device according to a third embodiment of the present invention will be described with reference to the drawings. The configuration of the third liquid crystal display device is the same as that of the first embodiment and the second embodiment in FIGS. 1 and 2, and the configuration of the light quantity correction unit 1 shown in FIG. 9 is different from that of the second embodiment. . Hereinafter, with reference to FIG. 9, the difference between the liquid crystal display device of the third embodiment and the second embodiment will be described. FIG. 9 is a block diagram illustrating a configuration example of the light amount correction unit 1 illustrated in FIG. 2 according to the third embodiment. The configuration added to the second embodiment is an error storage unit 16, which will be described below.

When the correction data stored in the position correspondence correction table 11 and / or the speed correction data stored in the response speed correction table 13 are correction coefficients, the numerical value of the display data obtained by multiplying the correction coefficient is the decimal point. May have a numerical value of In this case, when the correction control unit 15 rounds off the decimal part and sets the obtained result as an integer, an error occurs between the correction control unit 15 and the actual correction value.
Therefore, the correction control unit 15 stores the truncated decimal value in the error storage unit 16 for each pixel of the liquid crystal panel 3, and displays the correction result of the corresponding pixel in the next frame. This error is added to the data, and the addition result is corrected to display data, and the numerical value after the decimal point is stored again in the error storage unit 16 in association with each pixel. As a result, the calculation error is diffused into a plurality of frames, and the display data can be apparently corrected, and the image quality can be improved. Further, error diffusion processing may be performed by distributing errors to surrounding pixels. This process also diffuses the error generated in the calculation result to the peripheral pixels, so that the gradation can be apparently corrected, and the image quality can be improved.

<Fourth Embodiment>
Next, a liquid crystal display device according to a fourth embodiment of the present invention is described with reference to the drawings. The fourth liquid crystal display device has the same configuration as that of the first to third embodiments and FIGS. 1 and 2, and can be applied to the display devices of the respective embodiments, and can also be applied to conventional display devices. It is. In the fourth embodiment, the amount of irradiation light that is provided to face the liquid crystal panel 3 with the backlight 5 interposed therebetween and adjusts the amount of light emitted from the backlight 5 corresponding to the relative position of each scanning line in the block. As the adjusting means, the structure of the reflecting plate is adjusted.

As an example of the fourth embodiment, as shown in FIG. 10, a reflective plate facing the liquid crystal panel 3 is provided with a backlight 5 having a plurality of light sources (cold cathode tubes) interposed therebetween.
A reflective object R1 having a reflective surface parallel to the display surface of the liquid crystal panel 3 is provided on the base material, and the scanning order is set to the scanning line with the scanning order in the area corresponding to the block above the reflective object R1. A reflector R2 having a reflecting surface having a predetermined angle with respect to the display surface of the liquid crystal panel 3 is provided so that much light is reflected and irradiated. As a result, the light amount of the substrate shown in FIG. 10 is controlled by the relative position in the block by the light directly irradiated from the light source, the reflected light from the reflector R1, and the reflected light from the reflector R2. It has a structure.

  As described above, FIG. 10 adjusts the amount of light according to the shape of the reflector R2 provided on the upper part of the base material. As another example of the fourth embodiment, as shown in FIG. A reflective layer is provided so as to have a reflective surface substantially parallel to the display surface of the liquid crystal panel 3, and in the formation process of the reflective layer, the light source (cold cathode tube) is radiated for each region corresponding to the block. The reflective layer L1 is controlled in the thickness direction of the reflective layer L2 or a material having a different reflection efficiency is used so that the light is reflected and irradiated to the scanning line whose scanning order is behind. May be.

  Next, FIG. 10 adjusts the amount of light according to the shape of the reflector R2 provided on the upper part of the substrate. As yet another example of the fourth embodiment, as shown in FIG. The reflection plate is made independent so that light does not leak to the scanning lines of other blocks. In addition, for each region corresponding to the block, the light source is arranged so that the light emitted from the light source (cold cathode fluorescent lamp) is incident on the scanning line with the scanning order later in the scanning line. On the other hand, the scanning order may be denser as the rear part is reached.

As another example, as shown in FIG. 13, the arrangement positions of the LEDs for each block are as shown in FIG. 12 so that a larger amount of light is incident on the scanning line whose scanning order is behind. Or the density of the light diffuser of the light guide plate may be controlled.
Furthermore, as shown in FIG. 14, a protrusion is provided at each block boundary to suppress interference due to light leakage between the blocks, and to improve the adjustment density of the light amount at the upper and lower ends of the blocks. It may be. In this case, the reflective layer and the light source are not specified, and the protrusion itself is formed of a reflecting material, and the amount of light is adjusted in consideration of the reflected light from the reflecting material, thereby improving the light usage efficiency. Is possible.

<Fifth Embodiment>
Next, a liquid crystal display device according to a fifth embodiment of the present invention is described with reference to the drawings. The fifth liquid crystal display device has the same configuration as that of the first embodiment and FIG. However, as shown in FIG. 15, the portions for controlling the liquid crystal panel 3 and the backlight 5 are different. Hereinafter, the difference of the liquid crystal display device of the fifth embodiment from the first embodiment will be described with reference to FIG. FIG. 15 is a block diagram illustrating a configuration example of the liquid crystal display device according to the fifth embodiment. The same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  In this figure, the light quantity correction unit 17 controls the lighting pulse of the backlight control unit 4 according to the relative position of the light source in each block, that is, the voltage level or pulse width of the lighting pulse applied to the light source at each position of the block. Make adjustments. For example, in the block A, the light sources A-1 to A-5 belonging to the block A of the backlight 5 have a scanning order of A-1 → A-2 → A-3 → A-4 → A-5. In this order, the voltage level may be increased to increase the amount of light, or the pulse width for turning on the light source may be lengthened to increase the amount of light. As a result, the amount of light transmitted through the liquid crystal elements of each scanning line in the block is made to correspond relatively to the gradation, so that the gradation of each pixel of the scanning line is set to a predetermined amount as the scanning order becomes later in the block. Correction to increase can be performed.

Further, as in the first embodiment, the liquid crystal driving unit 2 applies each scanning line of the liquid crystal panel 3 (see FIG. 1A) to, for example, one line from the top of FIG. 1A toward the bottom. The next scan is sequentially performed, that is, image data (gradation degree) is written in parallel to each pixel of the scan line.
As in the first embodiment, the backlight control unit 4 corresponds to the count-up signal output from the counter unit 7 to be described later for each of the divided blocks in the backlight 5 (see FIG. 1B). Then, the lighting is performed with a predetermined width in the order of block A → block B →. For example, as shown in the timing chart of FIG. 3, the backlight control unit 4 sequentially turns on the lighting pulses PA, PB, PC,... Every time a count-up signal is input from the counter unit 7 as shown in the timing chart of FIG. , And the light sources of the blocks A, B, C,... Are turned on for a time corresponding to the pulse width. The state is initialized by the frame synchronization signal input every time the frame is changed, and the lighting pulse PA is output.

In addition, the control unit 6 outputs a scanning timing signal to the counter unit 7 every time a scanning signal is output to each scanning line in synchronization with the scanning signal output to each scanning line in the liquid crystal panel 3.
When the counter unit 7 counts the scanning signal and reaches the number of scanning lines in the block, the counter unit 7 starts a new count from the next count, and uses the count value as scanning order data for each scanning line in each block. 17 and outputs a count-up signal to the backlight control unit 4 every time it counts up.
The light quantity correction unit 17 controls the voltage level of the lighting pulse or the width of the lighting pulse for each light source according to the input scan order data, corresponding to the relative position of the light source.

Further, the present invention can be applied to the first to third embodiments. In this case, it is necessary to create the correction data of the position correspondence correction table 11 and the speed correction data of the response speed correction table 13 in consideration of the light quantity according to the fifth embodiment.
The correction data of the position correspondence correction table 11 and the speed correction data of the response speed correction table 13, and the control value of the lighting pulse voltage level or the lighting pulse width are obtained experimental data in which a plurality of people do not feel flicker. And created based on this experimental data (the same applies to the first to third embodiments).
In the first to fifth embodiments, the configuration of the backlight has been described, but the present invention may also be applied to the configuration of the front light.

  1 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is stored in a computer system. It is also possible to perform gradation correction processing or light source pulse width and voltage level adjustment processing by reading and executing. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer system” includes a WWW system provided with a homepage providing environment (or display environment). The “computer-readable recording medium” refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, and a CD-ROM, and a storage device such as a hard disk built in the computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

  The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

It is a conceptual diagram which shows the structural example of the liquid crystal display device by embodiment of this invention. It is a block diagram which shows the structural example of the drive circuit part of the liquid crystal display device by the 1st, 2nd and 3rd embodiment of this invention. 3 is a timing chart showing lighting pulses for each block of each light source of the backlight of the liquid crystal display device of FIG. 2. It is a block diagram which shows the structural example by 1st Embodiment of the light quantity correction | amendment part 1 in FIG. It is a wave form diagram which shows the transmittance | permeability of the pixel corresponding to the scanning signal in the operation | movement of the liquid crystal display device of 1st Embodiment, the lighting pulse which lights a light source per block, and a scanning line. FIG. 4 is a waveform diagram showing a correspondence between a waveform indicating a transient state of the transmittance of a liquid crystal element in each scanning line of the liquid crystal panel 3 and a lighting pulse. It is a block diagram which shows the structural example by 2nd Embodiment of the light quantity correction | amendment part 1 in FIG. It is a conceptual diagram of the table which shows a response | compatibility with the combination of the gradation of display data, and speed correction data. It is a block diagram which shows the structural example by 3rd Embodiment of the light quantity correction | amendment part 1 in FIG. It is a conceptual diagram of the cross section of the liquid crystal display device which shows the structure of the reflecting plate of an example of 4th Embodiment. It is a conceptual diagram of the cross section of the liquid crystal display device which shows the structure of the reflector of the other example of 4th Embodiment. It is a conceptual diagram of the cross section of the liquid crystal display device which shows the structure of the reflector of the other example of 4th Embodiment. It is a conceptual diagram of the cross section of the liquid crystal display device which shows the structure of the reflector of the other example of 4th Embodiment. It is a conceptual diagram of the cross section of the liquid crystal display device which shows the structure of the reflector of the other example of 4th Embodiment. It is a block diagram which shows the structural example of the drive circuit part of the liquid crystal display device by the 5th Embodiment of this invention. It is a conceptual diagram of the cross section of a backlight which shows the structure of the backlight in a prior art example. It is a wave form diagram which shows a response | compatibility with the waveform which shows the transient state of the transmittance | permeability of the liquid crystal element in each scanning line of the liquid crystal panel in a prior art example, and a lighting pulse.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,17 ... Light quantity correction | amendment part, 2 ... Liquid crystal drive part, 3 ... Liquid crystal panel, 4 ... Backlight control part, 5 ... Backlight, 6 ... Control part, 7 ... Counter part, 10 ... 1st correction part, 11 ... Position correspondence correction table, 12 ... second correction unit, 13 ... response speed correction table, 14 ... storage unit, 15 ... correction control unit, 16 ... error storage unit, 100 ... scanning line drive circuit, 101 ... data line action circuit, 102 ... Liquid crystal elements, A-1, A-2, A-3, A-4, B-1, B-2, B-3 ... Scanning lines, L1, L2, L3, L4, Lm-1, Lm ... Data line

Claims (10)

A liquid crystal having a plurality of scanning lines extending in a plurality of row directions, a plurality of data lines extending in a plurality of column directions, and a plurality of pixels provided corresponding to the intersections of the scanning lines and the data lines A panel,
A data line driving circuit for supplying display data to the data lines;
A scanning line driving circuit for supplying a scanning signal to the scanning line;
A light source provided corresponding to each block obtained by dividing a plurality of the scanning lines of the liquid crystal panel;
Light source control means for controlling lighting of the light source for each of the blocks in correspondence with the timing at which the scanning signal is applied to each of the scanning lines;
Signal correction means for correcting the display data applied to the pixels corresponding to the scanning lines in correspondence with the scanning order of the scanning lines in the block. apparatus.   The signal correction means has a correction table indicating a correction amount corresponding to the scanning order, reads a correction amount corresponding to each scanning line, and corrects the display data by the correction amount. The liquid crystal display device according to claim 1.   3. The liquid crystal display device according to claim 1, wherein the signal correction unit corrects the display data in response to a change in display data applied between frames.   The signal correction means has a correction table indicating a correction amount corresponding to a difference in display data applied between frames, reads a correction amount corresponding to the difference, and corrects the display data by the correction amount. The liquid crystal display device according to claim 3.   5. The apparatus according to claim 1, further comprising a light amount adjusting unit that adjusts the amount of light emitted from the light source corresponding to the scanning order in the block. Liquid crystal display device.   The liquid crystal display device according to claim 1, wherein the light amount adjusting unit adjusts the light amount emitted from the light source corresponding to the scanning order of the scanning lines in the block.   The light amount adjusting means is a reflector having a structure provided so as to be opposed to the liquid crystal panel with the light source interposed therebetween and reflecting a light amount of light corresponding to the scanning order of each of the scanning lines. The liquid crystal display device according to claim 6.   The liquid crystal display device according to claim 6, wherein the light amount adjusting unit controls a lighting time of the light source corresponding to the scanning order of the scanning lines in the block. A plurality of scanning lines extending in a plurality of row directions; a plurality of data lines extending in a plurality of column directions; and a plurality of pixels provided corresponding to intersections of the scanning lines and the data lines. A liquid crystal panel and a data line driving circuit for supplying display data to the data lines;
A scanning line driving circuit for supplying a scanning signal to the scanning line;
A light source provided corresponding to each block obtained by dividing a plurality of the scanning lines of the liquid crystal panel;
Light source control means for controlling the lighting of the light source for each block in correspondence with the timing at which the scanning signal is applied to the scanning line;
A liquid crystal display device, comprising: an irradiation light amount adjusting unit that adjusts an amount of light emitted from the light source corresponding to an order of scanning of the scanning lines in the block. A plurality of scanning lines extending in a plurality of row directions; a plurality of data lines extending in a plurality of column directions; and a plurality of pixels provided corresponding to intersections of the scanning lines and the data lines. A liquid crystal display device having a liquid crystal panel, a data line driving circuit for supplying display data to the data lines, and a scanning line driving circuit for supplying scanning signals to the scanning lines,
A light source control process for controlling the lighting of the light source provided corresponding to each block obtained by dividing the scanning line of the liquid crystal panel in accordance with the timing at which the scanning signal is applied to the scanning line;
And a signal correction process for correcting the display data applied to the pixels corresponding to the scanning lines in correspondence with the scanning order of the scanning lines in the block. .

Images