JP2003295838A - Drive circuit for liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving circuit for liquid crystal display device, which is reduced in the necessary amount of memories, suppressible in increase in circuit scale, high in the response speed of a liquid crystal, and superior in moving picture display performance. <P>SOLUTION: The driving circuit for liquid crystal display device comprises: a frame memory storing the present field picture data and outputting the present field picture as the previous field picture data after specified time delay; a data table for high-speed response holding output data by corresponding to each value of the previous field picture data and each value of the present field picture data; and a comparison circuit deciding the output data from the present field picture data and the previous field picture data by using the data table for the high-speed response. In the data value of the data table for the high-speed response, at least one color of three colors, R, G, B, differs from the other colors. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to a drive circuit for applying a voltage to the liquid crystal of each pixel.

[0002]

2. Description of the Related Art A display screen of a liquid crystal display device is composed of a large number of pixels arranged vertically and horizontally in a matrix, and each pixel is provided with an electrode for applying a voltage to liquid crystal. Display is performed by sequentially selecting each pixel that constitutes the display screen row by row, applying a voltage to the liquid crystal using the electrodes of each pixel, and changing the alignment state of the liquid crystal molecules to control the amount of light that passes through the liquid crystal. Is performed.

The time required to select all the rows, that is, all the pixels of the display screen is called one field period, and the voltage of the liquid crystal of each pixel is one field period.
It is rewritten to a new voltage once (of course, the same voltage is written when there is no change in the display).

Liquid crystal display devices are widely used in place of conventional CRTs because they are lightweight and consume a small amount of power and can provide precise display. However, it has been pointed out that the display quality of moving images is low.

As described above, in the liquid crystal display device,
A display is obtained by controlling the amount of transmitted light according to the alignment state of liquid crystal molecules. Therefore, when displaying a moving image, that is, changing the display, it is necessary to change the voltage applied to the liquid crystal to change the alignment state of the liquid crystal molecules. However, it takes a relatively long time for a liquid crystal molecule in a certain alignment state to change its alignment state by a newly applied voltage and to become another alignment state determined by the newly applied voltage. To do. Therefore, when an object that moves at high speed is displayed, the alignment state of the liquid crystal molecules does not reach a desired state during one field period, and an afterimage of the object is perceived, or the outline of the object appears blurred. There was a problem.

[0006]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a drive circuit of a liquid crystal display device which can compensate for the slow response of the liquid crystal and can obtain a moving image display of good quality.

Another object of the present invention is to provide a drive circuit of a liquid crystal display device which has a high response speed of liquid crystal and is excellent in moving image display performance without significantly increasing the required amount of memory and the circuit scale.

Further, according to the present invention, in a liquid crystal display device having a display mode for displaying black by compensating the liquid crystal retardation with the retardation of an optical compensation film like the OCB mode, a gradation color generated by the birefringence of the liquid crystal. The purpose is to reduce changes.

[0009]

A drive circuit for a liquid crystal display device according to the present invention comprises a frame memory for storing current field image data and outputting it as previous field image data after a delay of a fixed time, and a frame memory for the previous field image data. Using the high-speed response data table that stores output data corresponding to each value and each value of the current field image data, and using the high-speed response data table, output data is output from the current field image data and the previous field image data. A drive circuit of a liquid crystal display device, comprising: a comparison circuit for determining, wherein the data value of the high-speed response data table is R,
At least one of the three colors G and B is different from the other colors.

Further, the driving circuit of the liquid crystal display device of the present invention stores the current field image data, outputs the frame field data as the previous field image data after a delay of a predetermined time, and the one value of each value of the previous field image data. Section, and a high-speed response data table storing output data corresponding to a part of each value of the current field image data, and using the high-speed response data table, from the current field image data and the previous field image data A driving circuit for a liquid crystal display device, comprising: a comparison circuit for determining output data, wherein a data value of the high-speed response data table is different from other colors in at least one of the three colors R, G, B. It is characterized by

Further, the drive circuit of the liquid crystal display device of the present invention stores the conversion means for converting the bit length of the current field image data and the current field image data after the bit length conversion, and after delaying for a fixed time. A frame memory for outputting as previous field image data, a part of each value of the previous field image data, and a high speed response data table storing output data corresponding to part of each value of the current field image data, A driving circuit of a liquid crystal display device, comprising: a comparison circuit for determining output data from current field image data and previous field image data using a high-speed response data table, wherein the bit of the converted current field image data is It is characterized in that the length is different from other colors in at least one of the three colors of R, G and B.

Further, the drive circuit of the liquid crystal display device of the present invention stores the conversion means for converting the bit length of the current field image data and the current field image data after the bit length conversion, and after delaying for a fixed time. A frame memory for outputting as previous field image data, a part of each value of the previous field image data, and a high speed response data table storing output data corresponding to part of each value of the current field image data, A driving circuit of a liquid crystal display device, comprising: a comparison circuit that determines output data from current field image data and previous field image data using a high-speed response data table, wherein a data value of the high-speed response data table is , R, G, B, at least one color is different from other colors.

Further, the drive circuit of the liquid crystal display device of the present invention stores the current field image data, outputs the frame field for outputting as the previous field image data after delaying for a fixed time, and one value of each value of the previous field image data. Part, and a part of each value of the current field image data, a part of each value of the previous field image data, and a part of each value of the current field image data. Output data is determined from the current field image data and the previous field image data by using the interpolation difference data table that stores the interpolation difference data corresponding to each part, and the high-speed response data table and the interpolation difference data table. A drive circuit of a liquid crystal display device including a comparison circuit for performing data of the interpolation difference data table. There, R, G, for at least one color of the three colors of B being different from other colors for.

Further, the drive circuit of the liquid crystal display device of the present invention stores the conversion means for converting the bit length of the current field image data and the current field image data after the bit length conversion, and after delaying for a fixed time. A frame memory that outputs as previous field image data, a part of each value of the previous field image data, and a high-speed response data table that stores output data corresponding to part of each value of the current field image data, An interpolation difference data table storing interpolation difference data corresponding to a part of each value of the field image data and a part of each value of the current field image data, and the high-speed response data table and the interpolation difference data A comparison circuit that determines output data from current field image data and previous field image data using a table is provided. That a driving circuit of a liquid crystal display device, the bit length of the current field image data after the conversion to R, G, characterized in that different from the other colors for at least one color of the three colors of B.

Further, the drive circuit of the liquid crystal display device of the present invention stores the conversion means for converting the bit length of the current field image data and the current field image data after the bit length conversion, and after delaying for a fixed time. A frame memory that outputs as previous field image data, a part of each value of the previous field image data, and a high-speed response data table that stores output data corresponding to part of each value of the current field image data, An interpolation difference data table storing interpolation difference data corresponding to a part of each value of the field image data and a part of each value of the current field image data, and the high-speed response data table and the interpolation difference data A comparison circuit that determines output data from current field image data and previous field image data using a table is provided. That a driving circuit of a liquid crystal display device, the data value of the interpolation differential data table, R,
At least one of the three colors G and B is different from the other colors.

In the drive circuit of the liquid crystal display device of the present invention, the voltage applied to the liquid crystal determined from the output data is a voltage at which the liquid crystal has a transmittance determined by the current field image data after one field period has elapsed. Good to do.

Further, in the drive circuit of the liquid crystal display device of the present invention, one frame period is divided into a plurality of field periods corresponding to the three colors of RGB, and the three colors of R, G and B are divided into each field within one frame period. A liquid crystal display device of a field sequential system, which sequentially switches and displays during a period,
Based on the image data of the current field and the image data of the same color one frame before, an optimum drive voltage is applied to the liquid crystal so that the transmittance of the liquid crystal becomes the transmittance corresponding to the current field image after one field period. It is characterized by

Further, the drive circuit of the liquid crystal display device of the present invention is provided with the optimum drive voltage based on the image data of the current field and the image data of the same color one frame before as a high-speed response data table. is there.

Further, in the drive circuit of the liquid crystal display device of the present invention, when the data value of the high speed response data table is R,
At least one of the three colors G and B is different from the other colors.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1 A first embodiment of the present invention will be described with reference to FIG.

FIG. 1 shows the relationship between the applied voltage to the liquid crystal and the transmittance, with the horizontal axis representing time and the vertical axis representing transmittance in the conventional technique and the present embodiment. In the example of FIG. 1, the liquid crystal display is supposed to be rewritten at a frequency of 60 Hz, so that one field period is about 16.6 mse.
c. In FIG. 1, the liquid crystal is in the previous field (~ 20
In msec), the transmittance is displayed as 10%,
This is followed by a current field (20 msec-) with a transmittance of 5
Try to rewrite to 5%.

In the prior art, as indicated by a thin line S ₀ in FIG. 1, a voltage (hereinafter, V) at which the transmittance becomes 55% when the response of the liquid crystal is almost completed after a certain period of time elapses.
_{(Denoted as 55} ) was applied to the liquid crystal. Therefore, the transmittance of the liquid crystal does not reach 55% in the current field, which causes the deterioration of the moving image display quality.

Therefore, the present invention is characterized in that a voltage is applied to the liquid crystal during the current field, that is, one field period after the start of voltage application, so that the target transmittance is 55%. As indicated by a thick line S ₁ in FIG. 1, by applying a voltage V ₉₀ at which the transmittance becomes 90% when the response of the liquid crystal is almost completed, the transmittance of the liquid crystal after one field period is about 55. It can be%.

As described above, in the present embodiment, the voltage applied in the current field is set to a voltage at which the liquid crystal has a desired transmittance after one field period, so that an afterimage of an object is perceived or an outline of the object is sensed. Is not displayed as blurred,
A liquid crystal display device with good moving image display quality can be obtained.

Further, since the data value is different from other data for at least one of the three colors of RGB, the memory can be effectively used.

Embodiment 2 FIG. 2 is a diagram showing the relationship between the applied voltage and the transmittance in the current field with respect to the transmittance in various fields. From FIG. 2, when the transmittance in the previous field is 20%, in the current field, by applying the voltage V ₈₀ that makes the transmittance 80% in the state where the response of the liquid crystal is almost completed, one field period is applied. It will be seen later that a display with a transmittance of 55% is obtained. Similarly, when the transmittance in the previous field is 50%, 60%, and 70%, by applying the voltages V ₆₀ , V _50, and V ₄₀ , respectively, 1
It can be seen that the desired transmittance of 55% is obtained after the field period.

As described above, the voltage that gives the desired transmittance after one field period can be uniquely determined from the transmittance of the previous field. Therefore, by using the two-dimensional table (table) in which the transmittance of the previous field and the desired transmittance in the current field are set as rows and columns, and the voltage to be applied to the liquid crystal is arranged at the intersections of the rows and columns, The liquid crystal can have a desired transmittance after one field period, and a liquid crystal display device with good moving image display quality can be obtained.

An example of the table is shown in FIG. 3, and an example of a drive circuit using the table is shown in FIG. The table is called a high-speed response data table 20, and the image data of the previous field is shown as a row, and the image data displayed in the current field is shown as a column, with the transmissivity represented by 256 gradations. Further, at the intersection of the row and the column, image data to be supplied to the liquid crystal in the current field as output data is also arranged as 256 gradation data.

As shown in FIG. 4, the high speed response data table 20 is connected to the comparison circuit 30. The current field image data from the signal source is supplied to the comparison circuit 30 and the frame memory 10. Frame memory 1
0 stores current field image data, and the stored current field image data is read out as previous field image data after one field period has elapsed. The comparison circuit 30 applies the read previous field image data and current field image data to the rows and columns of the high-speed response data table 20, and outputs the image data at the intersection as output data.

As described above, each output data of the high-speed response data table 20 corresponds to the voltage required to change from the transmittance of the previous field image data to the transmittance of the current field image data within one frame. Is determined as the gradation data to be used. For example, when the image that has been displayed so far, that is, the gradation of the previous field image data is 64, and the image that is about to be displayed, that is, the gradation of the current field image data is 128, the difference between the two is calculated. In order to increase the value, a value larger than the gradation 128, for example, the gradation 144, is used as the output data. Since a voltage corresponding to the gradation 144 is applied to the liquid crystal and the response of the liquid crystal is accelerated, a desired gradation 128 display can be obtained after a lapse of one field period.

In the conventional technique which does not use the high-speed response data table 20 and the comparison circuit 30, when the gradation of the current field image data is 128, the voltage corresponding to this gradation 128 is applied to the liquid crystal. Therefore, it takes a longer time than one field until the alignment state of the liquid crystal actually reaches the steady state and the display of the gradation 128 is obtained. On the other hand, in this method, since the voltage corresponding to the gradation 144 is applied to the liquid crystal, the response of the liquid crystal is faster, and the state of the gradation 128 is reached after the lapse of one field period. In this way, by appropriately setting each output data of the high-speed response data table 20 in correspondence with the current field image data and the previous field image data, it is possible to improve the display quality of the moving image.

By the way, as a matter of course, this method requires a high-speed response data table and a frame memory. As in the above example, each of the previous field image data, the current field image data, and the output data is 25
In the case of 6 gradations, the size of the high-speed response data table is 64 Kbytes. In addition, the liquid crystal display device is vertically 10
XGA type consisting of 24 x 768 pixels, R
When the three colors of GB are color liquid crystals each having 256 gradations, the size of the frame memory for storing the previous field image data is about 2.3 Mbytes.

Therefore, this method requires a large amount of memory and a large number of data lines for connecting the comparison circuit and the frame memory and a large number of data lines for connecting the comparison circuit and the high-speed response data table. There is a possibility that the circuit scale will increase and the cost will increase.

Third Embodiment A third embodiment of the present invention will be described with reference to FIGS. 5, 6, 7, 8 and 9. In the present embodiment, the high-speed response data table is provided with output data of 256 gradations corresponding to 8 gradations each of the previous field image data and the current field image data having 256 gradations. As a result, the size of the high-speed response data table is only 64 bytes, and the required amount of memory and the number of data lines connected to the comparison circuit can be greatly reduced.

The operation of the drive circuit according to this embodiment will be described below with reference to the flow chart. Due to space limitations, the flow diagram shows two sheets at positions * 1, * 2, and * 3.
It is divided into FIGS. 5 and 6.

First, the frame memory is initialized (step S101), and the image data is stored in the initialized frame memory. At this time, the size of the frame memory may be reduced by converting the bit length of the image data using a threshold value and storing the converted image data in the frame memory. The bit length conversion can be performed by extracting the upper 4 bits of the image data having 256 gradations, as shown in FIGS. 8A and 8B, for example. The image data stored in the frame memory is read out as the previous field image data kd in step S103 described below after a delay of one field period.

Next, in step S102, the high-speed response data table 20 is acquired. As shown in FIG. 7, the high speed response data table 20 has eight gradations Td_div [i of the previous frame image data corresponding to id = 0 to 7.
d] and eight gray levels Td_div [jd] of the current frame image data corresponding to jd = 0 to 7, and these eight gray levels Td_div [id], Td_div [j
output data Td [id] of 256 gradations corresponding to
It is composed of [jd].

Further, in step S103, the current field image data bd and the previous field image data kd are acquired. In the present embodiment, the current field image data bd is data of 256 gradations, and the previous field image data kd is data of 4 bits = 16 gradations.

In a succeeding step S104, it is determined whether or not the current field image data bd has gradation 0 or gradation 255. When the gradation value of the current field image data is 0, the gradation data closest to the voltage required to change the transmittance of the previous field image data to the transmittance of the current field image data within one frame is 0. Become. If the current field image data has a gradation of 255, the gradation data closest to the voltage required to change the transmittance of the previous field image data to the transmittance of the current field image data within one frame is 255. Therefore, in this case, the process proceeds to step S105, and the current field image data bd is output as it is as the output data out.

When the current field image data bd is neither gradation 0 nor gradation 255, the output data out is determined using the high speed response data table. In this embodiment, as the high-speed response data table, only output data corresponding to the current field image data and the previous field image data of 8 gradations are prepared. Therefore, two-dimensional linear interpolation is performed, and
Output data out corresponding to the 6-gradation current field image data and the previous field image data is created. The method will be described below.

First, the previous field image data kd, which has 16 gradations by bit length conversion, is restored to 256 gradations. As shown in FIGS. 8B and 8C, the restoration is performed using the threshold value used in the conversion to 16 gradations. The image data kd restored to 256 gradations using the threshold value is represented as d_div [kd]. by the way,
The previous field image data kd of 16 gradations is set to the threshold value d_d.
It is not known which of iv [kd] and the threshold d_div [kd + 1] should be restored.

Therefore, this determination is made using the current field image data bd. First, step S106
And two threshold values d_div [kd] and d_div [kd + 1] corresponding to the previous field image data kd,
Differences ad1 and ad2 from the current field image data bd are obtained. Then, when the absolute value of ad1 is larger than the absolute value of ad2, the threshold value d_div [kd] is set as the restored previous field image data ad, and when the absolute value of ad2 is larger, the threshold value d_div [kd + 1] is restored. The previous field image data ad is set (step S109,
S110, S111).

In the following step S112, the restored previous field image data ad and the present field image data bd
Calculates the position on the high-speed response data table. As already described with reference to FIG. 7, the high-speed response data table has eight gradations Td_div [id] of the previous frame image data corresponding to id = 0 to 7 and the current frame image corresponding to jd = 0 to 7. It is composed of eight gradations Td_div [jd] of data. Therefore, these eight gradations Td_div [id] and Td_d
Of the 49 meshes whose boundaries are iv [jd], the mesh in which the image data ad and bd are located is calculated.

As a result of the calculation, the previous frame image data ad
, The gradation Td_div [id] and the gradation Td_div [i
d + 1] and the current frame image data bd is
The gradation Td_div [jd] and the gradation Td_div [jd +
1], this data D (ad, bd)
The position on the high-speed response data table is as shown in FIG. Here, in Td [id] [jd], the gradation of the previous frame image data is Td_div [id], and the gradation of the current frame image data is Td_div [j.
d] means output data.

Output data Td [id] [jd], T at the four corners of the grid to which the data D (ad, bd) belongs
From d [id] [jd + 1], Td [id + 1] [jd] and Td [id + 1] [jd + 1], data D (a
The output data out corresponding to d, bd) is calculated.

First, in step S113, the gradation Td_div [id + 1] and the gradation Td_ of the current frame image data are set.
difference isq from div [id], gradation Td_div [jd
The difference jsq between +1] and the gradation Td_div [jd] is calculated.

Next, in step S114, the data D (a
d, bd) is in the upper right triangle area or the lower left triangle area partitioned by a thin line in the mesh shown in FIG. When the data D (ad, bd) is in the upper right triangular area, the output data out is calculated in step S115.

In step S115, output data Td [id] [jd], Td corresponding to the three corners of the triangular area
[Id] [jd + 1] and Td [id + 1] [jd +
1], the three corners of the triangular area and the data D (a
The output data out is calculated as a function of the distance from d, bd).

In step S114, the data D (ad, b
If it is determined that d) is in the lower left triangular area,
In step S116, the same calculation as in step S115 is performed, and output data out is calculated.

The output data out is output in step S117, and the voltage corresponding to this output data out is applied to the liquid crystal of each pixel.

As described above, according to the present embodiment, the high-speed response data table is provided with the output data corresponding to each of 8 gradations of the previous field image data and the current field image data, and the linear table is provided. Since the output data corresponding to the previous field image data and the current field image data of 256 gradations is obtained by the interpolation, the memory capacity for storing the high speed response data table can be significantly reduced, and the high speed response data table can be obtained. It is possible to reduce the number of data lines connecting the comparator circuit and the comparison circuit and reduce the circuit scale.

Further, by converting the bit length of the image data to reduce the data amount and storing it in the frame memory, the size of the frame memory can be reduced, and the frame memory and the comparison circuit are connected. The number of data lines can be reduced and the circuit scale can be reduced.

In this embodiment, the previous field image data, the current field image data and the output data are 2
With 56 gradations, the high-speed response data table has 8 gradations of previous field image data, 8 gradations of current field image data,
Although the output data is composed of 256 gradations, the required memory amount and the circuit scale can be similarly reduced even if the number of gradations is different.

Further, the image data is converted into 4 bits and stored in the frame memory. The bit length after conversion is the required memory amount, the error associated with conversion and restoration, and the calculation amount required for conversion and restoration. It may be appropriately determined in consideration.

Further, since the data value is different from other data for at least one of the three colors of RGB, the memory can be effectively used.

In the present embodiment, the bit length of the image data is converted and stored in the frame memory to form the previous field image data. Therefore, the bits truncated at the time of conversion appear as an error when restoring the image data, and even if there is no change in the still image, that is, the image to be displayed, the previous field image data and the current field image data have different values. The still image may not be displayed correctly.

Therefore, step S107 is provided to determine whether or not the image is a still image. If the image is a still image, the current field image data bd may be directly used as the output data out (step S108). Step S
At 107, the current field image data bd is the upper and lower threshold values d_div corresponding to the previous field image data kd.
When it is within [kd] and d_div [kd + 1], it is determined to be a still image.

Fourth Embodiment A fourth embodiment of the present invention will be described with reference to FIGS. 10, 11 and 12. The operation of the drive circuit according to the present embodiment is shown in the flowchart of FIG.

First, the frame memory is initialized (step S201), and the image data is stored in the initialized frame memory. At this time, the threshold value is used to convert the bit length of the image data, and the converted image data is stored in the frame memory. Since the bit length conversion has been described in the third embodiment (FIG. 8), description thereof will be omitted here. The image data stored in the frame memory is delayed by one field period, and then, in step S203 described later.
Is read as the previous field image data kd.

Next, in step S202, the high speed response data table 20 is acquired. As shown in FIG. 11, the high-speed response data table 20 includes the previous frame image data whose bit length is converted to 8 gradations of id = 0 to 7 and the current frame image data corresponding to jd = 0 to 8 One gradation Td_div [jd], and these eight gradations i
The output data Td [id] [jd] has 256 gradations corresponding to d and Td_div [jd].

Further, in step S203, the current field image data and the previous field image data kd are acquired. With respect to the current field image data, the 8-field current field image data jd converted using the eight gradations Td_div [jd] as a threshold value and the non-converted (for example, 256 tone) current field image data bd. Both are acquired.

In a succeeding step S204, it is determined whether or not the current field image data bd has gradation 0 or gradation 255. When the gradation value of the current field image data is 0, the gradation data closest to the voltage required to change the transmittance of the previous field image data to the transmittance of the current field image data within one frame is 0. Become. If the current field image data has a gradation of 255, the gradation data closest to the voltage required to change the transmittance of the previous field image data to the transmittance of the current field image data within one frame is 255. Therefore, in this case, the process proceeds to step S205, and the current field image data bd is output as it is as the output data out.

When the current field image data bd has neither gradation 0 nor gradation 255, the output data out is determined using the high speed response data table. In this embodiment, as the high-speed response data table, only output data corresponding to the current field image data and the previous field image data of 8 gradations are prepared. Therefore, the linear interpolation is performed, and the output data ou corresponding to the 256-gradation current field image data bd is output.
Create t. The method will be described below.

First, in step S206, the previous field image data kd and the current field image data bd are compared. Since the previous field image data kd has 8 gradations by the bit length conversion, it is necessary to restore 256 gradations first. Restoration is performed using the threshold value used when converting to 8 gradations. For more information on restore,
Since it has been described in the third embodiment (FIG. 8), no further description will be given here. The previous field image data kd of 8 gradations,
Lower threshold d_div [kd] and upper threshold d_d
It is restored to iv [kd + 1] and the difference from the current field image data bd is obtained.

The current field image data bd is larger than the lower threshold value d_div [kd], and the upper threshold value d_.
If it is smaller than div [kd + 1], there is no change or only a small change between the current field image data and the previous field image data (step S207). So in this case,
The image is regarded as a still image, and the current field image data bd is directly used as the output data out (step S
208).

Next, the previous field image data k which gives the lower threshold d_div [kd] as the previous field image data id when using the high-speed response data table
In step S209, it is determined which of the d and the previous field image data kd + 1 that gives the upper threshold d_div [kd + 1] is used.

When the current field image data bd is smaller than the lower threshold value d_div [kd], the previous field image data kd giving the lower threshold value d_div [kd] is used in the high speed response data table. The previous field image data id at that time is set (step S210).
On the other hand, the current field image data bd has an upper threshold value d_
If it is larger than div [kd + 1], the previous field image data kd + 1 giving the upper threshold d_div [kd + 1] is set as the previous field image data id when using the high-speed response data table (step S21).
1). By determining the previous field image data id in this manner, the transmittance after one frame becomes a smooth display between the transmittance of the current field image data and the transmittance of the previous field image data, and the transmittance of the current field image data is It is possible to prevent the display other than the transmittance between the transmittance and the transmittance of the previous field image data.

The previous field image data id determined in step S210 or S211, and step S203
Using the converted current field image data jd acquired in step 1, the output data Td [id] [jd] corresponding to the both are read from the high-speed response data table. Further, the current field image data bd before conversion is the threshold value Td_div [j corresponding to the current field image data jd after conversion.
d] and the threshold value Td_div [jd + 1] corresponding to the converted current field image data jd + 1, the output data Td corresponding to the previous field image data id and the converted current field image data jd + 1.
[Id] [jd + 1] is also read from the high-speed response data table.

The read output data Td [id] [j
The positional relationship between d], Td [id] [jd + 1] and the previous field image data id and the current field image data bd before conversion is as shown in FIG. Therefore, the output data Td [id] [jd], Td [id] [jd +
1] and the distance between the three of the current field image data bd and output data Td [id] [jd], Td [id]
The output data out corresponding to the current field image data bd can be calculated from the value of [jd + 1] by one-dimensional linear interpolation (step S212).

The output data out is output in step S213, and the voltage corresponding to this output data out is applied to the liquid crystal of each pixel.

As described above, according to the present embodiment, the high-speed response data table is provided with the output data corresponding to each of the 8 gradations of the previous field image data and the current field image data, and the linear table is provided. Since the output data corresponding to the previous field image data converted to 8 gradations and the current field image data of 256 gradations is obtained by the interpolation, the memory capacity for storing the high speed response data table can be significantly reduced. It is possible to reduce the number of data lines connecting the high-speed response data table and the comparison circuit and reduce the circuit scale.

Further, since the bit length of the image data is converted to reduce the data amount and then stored in the frame memory,
It is possible to reduce the size of the frame memory, reduce the number of data lines connecting the frame memory and the comparison circuit, and reduce the circuit scale.

In the present embodiment, the previous field image data, the current field image data and the output data are 2
With 56 gradations, the high-speed response data table has 8 gradations of previous field image data, 8 gradations of current field image data,
Although the output data is composed of 256 gradations, the required memory amount and the circuit scale can be similarly reduced even if the number of gradations is different.

Further, the number of gradations of the previous field image data depends on the required memory amount, the error due to conversion and restoration,
It may be appropriately determined in consideration of the amount of calculation required for conversion and restoration.

Further, since the data value is different from other data for at least one of the RGB three colors, the memory can be effectively used.

Fifth Embodiment A fifth embodiment of the present invention will be described with reference to FIGS. 13 and 14. In the fourth embodiment, two adjacent output data in the high speed response data table are used and linear interpolation is performed to determine the output data out. In the present embodiment, an interpolation difference data table is used in addition to the high-speed response data table, and the output difference data table of the high-speed response data table is interpolated using the interpolation difference data of the interpolation difference data table. It is characterized by performing.

The operation of the drive circuit according to this embodiment is shown in the flow chart of FIG.

First, the frame memory is initialized (step S301), and the image data is stored in the initialized frame memory. At this time, the threshold value is used to convert the bit length of the image data, and the converted image data is stored in the frame memory. Since the bit length conversion has been described in the third embodiment (FIG. 8), description thereof will be omitted here. The image data stored in the frame memory is delayed by one field period and then, in step S303 described later.
Is read as the previous field image data kd.

Next, in step S302, the high-speed response data table 20 and the interpolation difference data table 21 are acquired. Similar to the fourth embodiment (FIG. 11), the high-speed response data table 20 includes the previous frame image data whose bit length is converted to 8 gradations of id = 0 to 7, and jd.
= 0 to 7 corresponding to eight gradations Td_div [jd] of the current frame image data, and these eight gradations id,
It is composed of output data Td [id] [jd] of 256 gradations corresponding to Td_div [jd]. The interpolating difference data table 21 also includes the previous frame image data whose bit length is converted to 8 gradations of id = 0 to 7 and jd = 0.
8 gradations Td of the current frame image data corresponding to
_Div [jd], and these eight gradations id, Td
Interpolation difference data Td_v corresponding to _div [jd]
It is composed of [id] and [jd].

In step S303, the current field image data and the previous field image data kd are acquired. With respect to the current field image data, the 8-field current field image data jd converted using the eight gradations Td_div [jd] as a threshold value and the non-converted (for example, 256 tone) current field image data bd. Both are acquired.

In a succeeding step S304, it is determined whether or not the current field image data bd has gradation 0 or gradation 255. When the gradation value of the current field image data is 0, the gradation data closest to the voltage required to change the transmittance of the previous field image data to the transmittance of the current field image data within one frame is 0. Become. If the current field image data has a gradation of 255, the gradation data closest to the voltage required to change the transmittance of the previous field image data to the transmittance of the current field image data within one frame is 255. Therefore, in this case, the process proceeds to step S305, and the current field image data bd is output as it is as the output data out.

When the current field image data bd is neither gradation 0 nor gradation 255, the output data out is determined using the high speed response data table. In this embodiment, as the high-speed response data table, only output data corresponding to the current field image data and the previous field image data of 8 gradations are prepared. Therefore, interpolation is performed to create output data out corresponding to the 256-gradation current field image data bd. The method will be described below.

First, in step S306, the previous field image data kd and the current field image data bd are compared. In the present embodiment, the current field image data bd is converted into the current field image data jd using the threshold value used when converting the image data into the previous field image data kd. Therefore, the previous field image data kd and the current field image data jd are directly compared.

As a result of the comparison, the previous field image data kd
If the current field image data jd is equal to the current field image data jd, there is no change or only a small change between the current field image data and the previous field image data. Therefore, in this case, the image is regarded as a still image, and the current field image data bd is directly used as the output data out (step S30).
7).

Next, in step S308, it is determined which of the previous field image data kd and the previous field image data kd + 1 is used as the previous field image data id when the high speed response data table is used.

When the current field image data jd is smaller than the previous field image data kd, this previous field image data kd is set as the previous field image data id when the high speed response data table is used (step S309). On the other hand, when the current field image data jd is larger than the previous field image data kd, the previous field image data kd + 1 is set as the previous field image data id when the high speed response data table is used (step S310). By determining the previous field image data id in this manner, the transmittance after one frame becomes a smooth display between the transmittance of the current field image data and the transmittance of the previous field image data, and the transmittance of the current field image data is It is possible to prevent the display other than the transmittance between the transmittance and the transmittance of the previous field image data.

The previous field image data id determined in step S309 or S310, and the step S303.
Using the converted current field image data jd acquired in step 1, the output data Td [id] [jd] corresponding to the both are read from the high-speed response data table. Similarly, and also from the interpolation difference data table, the interpolation difference data Td_v [id] [jd] corresponding to both are read.

The read output data Td [id] [j
12] and the previous field image data id and the current field image data bd before conversion are as shown in FIG. Therefore, bd-Td_div [j
output data Td [id] [j
d] and the current field image data bd are multiplied by the read difference data for interpolation Td_v [id] [jd] and added to the output data Td [id] [jd] to obtain the current field image data bd. The corresponding output data out can be calculated (step S311).

The output data out is output in step S312, and the voltage corresponding to this output data out is applied to the liquid crystal of each pixel.

As described above, according to the present embodiment, the output data corresponding to each of 8 gradations of the previous field image data and the current field image data and the interpolation difference data are provided for high speed response. Since the data table and the differential data table for interpolation are provided and the output data is interpolated using the differential data for interpolation, the memory capacity for storing the high-speed response data table and the differential data table for interpolation is significantly increased. It is possible to reduce the number of data lines connecting the high-speed response data table and the comparison circuit and the interpolation difference data table and the comparison circuit to reduce the circuit scale, and further reduce the calculation amount. This also makes it possible to reduce the circuit scale.

Further, since the bit length of the image data is converted to reduce the data amount and then stored in the frame memory,
It is possible to reduce the size of the frame memory, reduce the number of data lines connecting the frame memory and the comparison circuit, and reduce the circuit scale.

In this embodiment, the previous field image data, the current field image data and the output data are 2
56 gradations, the high-speed response data table and the interpolation difference data table are 8 gradations of the previous field image data,
Although the present field image data is configured to correspond to 8 gradations, the required memory amount and the circuit scale can be similarly reduced for other gradation numbers.

The number of gradations of the previous field image data depends on the required memory amount, the error due to conversion and restoration,
It may be appropriately determined in consideration of the amount of calculation required for conversion and restoration.

Further, since the data value is different from other data for at least one of the three colors of RGB, the memory can be effectively used.

Sixth Embodiment In this embodiment, the present invention is applied to an OCB mode liquid crystal display device.

The OCB mode is a display mode excellent in high-speed response characteristics and wide viewing angle characteristics, and is described in the literature (Y. Yamaguchi
Et al., SID93DIGEST, p.277, or T. Miyashita et al., Eu
roDisplay93, p.149) and so on.

FIG. 15 shows the structure of a liquid crystal panel in the OCB mode. In FIG. 15, 31 is an electrode substrate and 32 is a color filter substrate (hereinafter referred to as CF substrate). A plurality of pixels are formed in a matrix on the electrode substrate 31, and a TFT (Thin Film Transistor) of a switching element is provided for each pixel.
sistor) is provided. The CF substrate 32 is provided with micro color filters of RGB colors for color display. Reference numeral 33 is an alignment film. The alignment film 33 is rubbed. The rubbing direction is substantially parallel to the upper and lower substrates. 34 is a bend liquid crystal layer, 35 and 36 are optical compensation films, 37 and 38 are polarizing plates, 40 is a surface including the alignment direction of liquid crystal molecules, 41 is a rubbing direction of the alignment film 33, and 42 and 43 are polarizing plates 37 and 38. Is the transmission axis of.

In the OCB mode, p-type liquid crystal having a positive dielectric anisotropy is used. The alignment state is bend alignment, and a voltage is applied between the pixel electrode provided on the electrode substrate 31 and the counter electrode provided on the CF substrate 32 to change the alignment state. The transmittance is controlled by changing the retardation of the liquid crystal layer 34 accompanying the alignment change between the first voltage (OFF voltage) which is not 0 V and the second voltage (ON voltage) higher than the first voltage. In the OCB mode, it is necessary to set the off voltage to about 2.0 to 2.5 V in order to maintain the bend orientation.

A case where an optical compensation film for compensating the retardation of the liquid crystal layer when an off voltage is applied is attached so that black is displayed when an off voltage is applied is called normally black. Conversely, a black display is obtained when an on voltage is applied. The case of attaching an optical compensation film for compensating the retardation of the liquid crystal layer when the on-voltage is applied is called normally white. Normally white is used because normally white has a smaller retardation of the liquid crystal layer during black display and is less susceptible to temperature changes.

As the optical compensation films 35 and 36, a laminated film obtained by combining a hybrid-oriented discotic liquid crystal film, a negative c plate, a uniaxial film, a biaxial film and the like is used. The optical compensation film is an important constituent member that determines the driving voltage and the viewing angle characteristics.

The OCB mode can realize a high-speed response and a wide viewing angle at the same time, and is a very promising display system for liquid crystal display devices mainly for displaying moving images. However, since black display is performed by compensating the retardation of the liquid crystal layer with the retardation of the optical compensation film, the color change in the low gradation range (around black display) is large due to the difference in the birefringence wavelength dispersion between the two. There is.

FIG. 16 shows an OCB mode liquid crystal display device,
The dependency of the applied voltage on the transmittance is shown. The liquid crystal display device is a normally white type, and the driving voltage is 2.5V.
V, ON voltage is 5.5V. The liquid crystal material has a smaller birefringence wavelength dispersion than the optical compensation film. FIG. 17 shows an enlarged view of the transmittance change near the black display voltage. As the applied voltage increases, first the transmittance of short wavelength (450 nm) corresponding to blue becomes minimum, and then the green,
The transmittance of wavelengths (550 and 650 nm) corresponding to red is minimized. The minimum voltage of transmittance at 450 nm is Von
If it is (B), it is yellow at a voltage below Von (B),
It becomes blue when the voltage is Von (B) or higher. As a result, the display color of the liquid crystal display device changes to yellow and then to blue as the gradation becomes lower.

Regarding the problem of gradation color change, a method has been proposed in which the pretilt angle is changed for each pixel and the gradation-transmittance curves of the respective pixels are made uniform (Matsushita, Japanese Patent Laid-Open No. 10-1771).
No. 74), however, requires new steps such as mask rubbing and light irradiation, resulting in an increase in manufacturing cost.

As another method, a method of matching the birefringence wavelength dispersions of the liquid crystal material and the film material (Fuji Film, JP-A-9-329785) has been proposed. When a system is used, electro-optical characteristics other than color characteristics and reliability over time are impaired.

In the OCB mode liquid crystal display device shown in FIGS. 16 and 17, the data table for high speed response corresponding to the voltage map as shown in Table 1 is applied only to the blue pixel. Green,
The diagonal term of the high-speed response data table of each red pixel is set to be the same as the gradation of the previous frame or the next frame. In Table 1, only the diagonal terms of the voltage in the low gradation range (around the ON voltage) are shown. As an actual high-speed response data table, non-diagonal terms suitable for improving response characteristics are also set,
In addition, the gradation data table is used instead of the voltage data table (the voltage data table is used for explanation here).

[0106]

[Table 1]

By using the voltage data table shown in Table 1, only the blue pixel has a substantial ON voltage of 5.2V.
(The voltage of 5.2 to 5.5 V is not applied to the blue pixel), the gradation color change in the low gradation region can be significantly suppressed.

The gradation data table corresponding to the voltage data table of Table 1 is, for example, as shown in Table 2.
Off-diagonal terms are not shown. Table 2 shows 6-bit gradation (6
4 gradations) and the pixel applied voltage at the time of 0 gradation display is 5.
6 is a gradation data table when gradation is set so that a pixel applied voltage at the time of 5 V and 2 gradation display becomes 5.2 V.

[0109]

[Table 2]

Although the case where the birefringence wavelength dispersion of the liquid crystal is smaller than that of the optical compensation film is described in the present embodiment, the present invention can be applied to the case where the birefringence wavelength dispersion of the liquid crystal is larger than that of the optical compensation film.

In the present embodiment, the color compensation is performed by assuming that only the high-speed response data table for the blue pixel is different from the other pixels, but if necessary, the green or red pixel,
Further, or three independent high speed response data tables may be used.

High-speed response data table The method of suppressing the gradation color change in the low gradation range by the diagonal term is not limited to the OCB mode, and the black display is performed by compensating the retardation of the liquid crystal with the retardation of the optical compensation film. It is applicable to all display modes. For example, a bend alignment mode other than the OCB mode (bend alignment mode in which initial alignment is twist alignment, multi-domain bend alignment mode, etc.), or ECB using uniaxial alignment or twist alignment
(Electrically controlled birefringence) mode.

Next, FIG. 18 shows a basic algorithm for creating a gradation output of blue pixels according to the present embodiment.

First, the frame memory is initialized (step S301), and the image data is stored in the initialized frame memory. The image data stored in the frame memory is read out as the previous field image data kd in step S303, which will be described later, after a delay of one field period.

Next, in step S302, the high-speed response data table 20 is acquired. The high-speed response data table 20 is dedicated to blue pixels and has the low gradation correction function shown in Table 2 incorporated therein. The other high speed response data tables for red and green images are the same as those shown in FIG. 4 used in the second embodiment.

In step S303, the current field image data and the previous field image data kd are acquired.

In a succeeding step S304, it is determined whether or not the current field image data bd has gradation 0 or gradation 255. When the gradation value of the current field image data is 0, the gradation data closest to the voltage required to change the transmittance of the previous field image data to the transmittance of the current field image data within one frame is 0. Become. If the current field image data has a gradation of 255, the gradation data closest to the voltage required to change the transmittance of the previous field image data to the transmittance of the current field image data within one frame is 255. Therefore, in this case, the process proceeds to step S305, and the current field image data bd is output as it is as the output data out.

When the current field image data bd is neither gradation 0 nor gradation 255, the output data out is output using the high speed response data table in step S311.
Is determined (step S312).

Here, since the grayscale output of the blue pixel is different from the current field and the previous field even if it is a still image, the still image detection is not performed unlike the above-described embodiment.

19 and 20 show an algorithm for creating a grayscale output of a blue pixel when bit length conversion is performed using a threshold value and linear interpolation is performed on the grayscale output as in the third embodiment. 5 and 6 of the third embodiment is different from the first embodiment in that the high-speed response data table 20 is dedicated to blue pixels in which the functions shown in Table 2 are incorporated, and still image detection (step S1
07) and still image gradation processing (step S108) are not performed, and pixels of other colors are shown in FIGS.
Perform the same processing as.

Here, regarding the bit length conversion, R, G,
It is not necessary to convert all the colors of B to the same bit length, and the effective use of the memory can be increased by allocating the bit length according to the importance of the information amount. For example, it is desirable to allocate 16-bit memory to R, G, and B at 5: 6: 5.

FIG. 21 shows an algorithm for creating a grayscale output of a blue pixel when bit length conversion is performed using a threshold value and linear interpolation is performed on the grayscale output, as in FIG. 10 of the fourth embodiment. In this case also, still image detection is not performed for blue pixels, and a high-speed response data table dedicated to blue pixels incorporating the functions shown in Table 2 is used. Linear interpolation is bd
It is performed along the direction (current data direction).

22 and 23 show the case where the interpolation difference data table is used for the linear interpolation as in FIG. 13 of the fifth embodiment. As for the interpolation difference data table, a data table dedicated to the blue pixel is used as in the high speed response data table. In FIG. 23, still image detection (step S306) is performed. When a still image is detected, a still image data table dedicated to the blue pixel only having diagonal elements incorporating the function of Table 2 (step S30).
7: out = Td_s [bd]) is used. Since this still image data table has only diagonal elements, it can be a vector instead of a matrix,
The processing speed can be increased.

In this embodiment, an example of using the high-speed response data table dedicated to the blue pixel, which is the most necessary in the OCB mode among the three colors of RGB, has been described. A dedicated data table may be used for colors. The same applies to the interpolation difference data table and the still image data table.

Embodiment 7 In this embodiment, the present invention is applied to a field sequential type liquid crystal display device. The field sequential method divides one frame, which is a display unit period of three colors of RGB, into three subframes (fields) corresponding to each color of RGB, and sequentially switches and displays images of each color within each subframe period. Is. Therefore, the display period of each color is ⅓ of that in the system using three color filters, and the demand for the response time of the liquid crystal layer is severe. Therefore, the effect of applying the present invention that equivalently shortens the response time of the liquid crystal layer is great.

In the above-described embodiment, the driving voltage is applied to the liquid crystal so that the transmittance of the liquid crystal becomes the transmittance required in the current field in the period from the current field to the next field in the three-color simultaneous display system. When applied to the field sequential method, the liquid crystal transmittance is required in the current display color subframe within the period from the current display color subframe (field) to the next display color subframe. A drive voltage that gives a transmittance is applied. In the field sequential method,
Since the OCB mode liquid crystal driving with fast response is applied, the high speed response data table dedicated to the blue pixel is used as in the sixth embodiment. The gradation data for driving the liquid crystal is created in parallel with the three-color simultaneous display method in the three-color simultaneous display method, but in the field sequential method, the three-color gradation data is generated for each of the three colors. Subframes (fields) are sequentially switched and performed. Also, the previous field image data in the three-color simultaneous display system corresponds to image data of the same color one frame before, that is, three subframes (fields) before in the field sequential system. In other respects, there is no difference between the three-color simultaneous display system and the field sequential system, and the gradation data creation algorithm and drive circuit used in the sixth embodiment can be used.

[0127]

According to the present invention, since the voltage applied in the current field is set to a voltage at which the liquid crystal has a desired transmittance after one field period, the afterimage of the object is perceived or the outline of the object is blurred. It is possible to obtain a liquid crystal display device which is not displayed and has good moving image display quality.

Further, according to the present invention, the transmittance in the previous field and the desired transmittance in the current field are set as rows and columns, respectively, and a voltage to be applied to the liquid crystal is arranged at the intersection of the rows and columns for high-speed response. By using the data table, the liquid crystal can have a desired transmittance after one field period, and a liquid crystal display device with good moving image display quality can be obtained.

Further, according to the present invention, the memory for storing the high speed response data table and the data line connecting the comparison circuit and the high speed response data table can be reduced, the circuit scale is small and the cost is low. It is possible to obtain a driving circuit of a liquid crystal display device having excellent moving image display performance.

Further, since the data value of the high speed response data table is made different from other colors for at least one of the three colors of R, G, B, it is possible to adjust the tone to be blue in the low gradation of the OCB mode. Color defects can be improved.

Further, according to the present invention, the frame memory for storing the previous field image data and the data line connecting the comparison circuit and the frame memory can also be reduced, the circuit scale is small and the cost is low. It is possible to obtain a driving circuit of a liquid crystal display device having excellent display performance.

Further, according to the present invention, since the difference data for interpolation stored in the difference data table for interpolation is used and the output data is determined from the current field image data and the previous field image data, the calculation amount is reduced. It is possible to obtain a driving circuit of a liquid crystal display device which is excellent in moving image display performance while reducing the circuit scale.

Further, according to the present invention, the bit length of the previous field image data and the bit length of the previous field image data of the high speed response data table are made equal to reduce the calculation amount for performing the interpolation. Can
It is possible to obtain a driving circuit for a liquid crystal display device which has a small circuit scale, is inexpensive, and has excellent moving image display performance.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between a voltage applied to a liquid crystal and a transmittance in a driving method according to a conventional technique and a driving method according to the present invention.

FIG. 2 is a diagram showing the relationship between the applied voltage in the current field and the transmittance after the lapse of one field period, with respect to the transmittances of several types of previous fields.

FIG. 3 is a diagram showing a high-speed response data table according to the present invention.

FIG. 4 is a schematic diagram illustrating a configuration of a drive circuit according to the present invention.

FIG. 5 is a flowchart illustrating an operation of the drive circuit according to the third embodiment of the present invention.

FIG. 6 is a flowchart illustrating the operation of the drive circuit according to the third embodiment of the present invention.

FIG. 7 is a diagram showing a high-speed response data table according to the present invention.

FIG. 8 is a diagram for explaining conversion and restoration of a bit length of image data based on a threshold value.

FIG. 9 is a diagram illustrating linear interpolation using a high-speed response data table.

FIG. 10 is a flowchart illustrating the operation of the drive circuit according to the fourth embodiment of the present invention.

FIG. 11 is a diagram showing a high-speed response data table according to the present invention.

FIG. 12 is a diagram illustrating linear interpolation using a high-speed response data table.

FIG. 13 is a flowchart illustrating the operation of the drive circuit according to the fifth embodiment of the present invention.

FIG. 14 is a diagram showing an interpolation difference data table according to the fifth embodiment of the present invention.

FIG. 15 is a diagram showing a configuration of an OCB mode liquid crystal display panel.

FIG. 16 is a diagram showing the transmittance dependency of an OCB mode liquid crystal display device.

FIG. 17 is a diagram showing the transmittance dependency shown in FIG. 16 in the vicinity of a black display voltage.

FIG. 18 is a flowchart illustrating the operation of the drive circuit that creates grayscale data according to the sixth embodiment of the present invention.

FIG. 19 is a flowchart illustrating the operation of the drive circuit that creates grayscale data according to the sixth embodiment of the present invention.

FIG. 20 is a flowchart illustrating the operation of the drive circuit that creates grayscale data according to the sixth embodiment of the present invention.

FIG. 21 is a flowchart illustrating the operation of the drive circuit that creates grayscale data according to the sixth embodiment of the present invention.

FIG. 22 is a flowchart illustrating the operation of the drive circuit that creates grayscale data according to the sixth embodiment of the present invention.

FIG. 23 is a flowchart illustrating an operation of a drive circuit that creates grayscale data according to a sixth embodiment of the present invention.

[Explanation of symbols]

10 frame memory, 20 high speed response data table, 21 interpolation difference data table, 30 comparison circuit, 31 electrode substrate, 32 CF substrate, 33 alignment film,
34 bend liquid crystal layer, 35, 36 optical compensation film,
37, 38 Polarizing plate, 40 Alignment plane of liquid crystal molecules, 41
Rubbing direction of alignment film, 42, 43 Transmission axis of polarizing plate.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G09G 3/20 G09G 3/20 631R 631V 632 632C 641 641C 641P 641R 642 642J 3/34 3/34 J (72 ) Inventor Akima Yuki 2-3-3 Marunouchi, Chiyoda-ku, Tokyo Sanryo Electric Co., Ltd. (72) Inventor Shin Tabata 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Sanryo Electric Co., Ltd. (72) Invention Toshio Tobita 2-3-3 Marunouchi, Chiyoda-ku, Tokyo Sanryo Electric Co., Ltd. (72) Inventor Tetsuya Satake 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Sanryo Electric Co., Ltd. (72) Inventor Kurata Tetsuyuki 2-3-3 Marunouchi, Chiyoda-ku, Tokyo Sanryo Electric Co., Ltd. (72) Inventor Shiro Miyake Kumamoto Address: 997 Miyoshi, Nishigoshi-cho, Kikuchi-gun Incorporated company Advanced Display (72) Inventor Kazuhiro Kobayashi, 997 Miyoshi, Nishigoshi-cho, Kikuchi-gun, Kumamoto Incorporated Advanced Display (72) Keiichi Murayama Nishigoshi-cho, Kikuchi-gun Miyoshi 997 Address F-Term in Advanced Display Company (Reference) 2H093 NA41 NA51 NC00 NC29 NC34 ND32 ND42 ND54 ND60 NE01 NE03 NE04 NE06 NE10 NF04 NH04 NH15 5C006 AC21 AF03 AF04 AF13 AF26 AF45 AF46 BA19 BB16 BB29 EA01 FA14 FA14 FA14 FA14 FA14 FA14 FA14 FA14 FA14 FA 5C080 AA10 BB05 CC03 DD01 DD08 DD22 DD23 EE19 EE29 FF11 GG09 GG12 GG17 JJ02 JJ05 JJ07

Claims (11)

[Claims] 1. A frame memory which stores current field image data and outputs it as a previous field image data after delaying for a fixed time, and outputs corresponding to each value of the previous field image data and each value of the current field image data. A drive circuit for a liquid crystal display device, comprising: a high-speed response data table storing data; and a comparison circuit that determines output data from current field image data and previous field image data using the high-speed response data table. Then, the data value of the high-speed response data table is
A driving circuit for a liquid crystal display device, which is different from other colors in at least one of the three colors of R, G, and B. 2. A frame memory for storing the current field image data and outputting it as the previous field image data after delaying for a fixed time, a part of each value of the previous field image data, and each value of the current field image data. A liquid crystal having a high-speed response data table in which output data is stored corresponding to a part, and a comparison circuit which determines output data from current field image data and previous field image data by using the high-speed response data table. A drive circuit of a display device, wherein the data value of the high-speed response data table is different from other colors in at least one of the three colors of R, G, and B. 3. A conversion means for converting the bit length of the current field image data, a frame memory for storing the current field image data after the bit length conversion and outputting it as the previous field image data after a delay of a certain time. A high-speed response data table in which output data is stored corresponding to a part of each value of the previous field image data and a part of each value of the current field image data, and A driving circuit for a liquid crystal display device, comprising: a comparison circuit for determining output data from field image data and previous field image data, wherein the bit length of the converted current field image data is R, G, B.
A driving circuit for a liquid crystal display device in which at least one of the three colors is different from other colors. 4. A conversion means for converting the bit length of the current field image data, a frame memory for storing the current field image data after the bit length conversion and outputting as the previous field image data after a delay of a fixed time, A high-speed response data table in which output data is stored corresponding to a part of each value of the previous field image data and a part of each value of the current field image data, and A drive circuit for a liquid crystal display device, comprising: a comparison circuit for determining output data from field image data and previous field image data, wherein the data value of the high-speed response data table is one of R, G, and B colors. A drive circuit for a liquid crystal display device, which is different from other colors for at least one color. 5. A frame memory for storing current field image data and outputting it as a previous field image data after delaying for a fixed time, a part of each value of the previous field image data, and each value of the current field image data. A high-speed response data table that stores output data corresponding to a part, and a part of each value of the previous field image data and a part of each value of the current field image data, and stores the differential data for interpolation Driving a liquid crystal display device including an interpolated difference data table, and a comparison circuit that determines output data from current field image data and previous field image data using the high-speed response data table and the interpolated difference data table. In the circuit, the data value of the interpolation difference data table is at least one of the three colors R, G, and B. The driving circuit of a liquid crystal display device that is different from other colors. 6. A conversion means for converting the bit length of the current field image data, a frame memory for storing the current field image data after the bit length conversion and outputting it as the previous field image data after a delay of a fixed time. A part of each value of the previous field image data, and a high-speed response data table that stores output data corresponding to each part of the current field image data, and a part of each value of the previous field image data, and Using the interpolation difference data table storing the interpolation difference data corresponding to a part of each value of the current field image data, the high-speed response data table and the interpolation difference data table, the current field image data and A drive circuit for a liquid crystal display device, comprising: a comparison circuit that determines output data from previous field image data; A driving circuit for a liquid crystal display device in which the bit length of the converted current field image data is different from other colors for at least one of the three colors of R, G, and B. 7. A conversion means for converting the bit length of the current field image data, a frame memory for storing the current field image data after the bit length conversion and outputting it as the previous field image data after a delay of a certain time. A part of each value of the previous field image data, and a high-speed response data table that stores output data corresponding to each part of the current field image data, and a part of each value of the previous field image data, and Using the interpolation difference data table storing the interpolation difference data corresponding to a part of each value of the current field image data, the high-speed response data table and the interpolation difference data table, the current field image data and A drive circuit for a liquid crystal display device, comprising: a comparison circuit that determines output data from previous field image data; A drive circuit of a liquid crystal display device in which a data value of the interpolation difference data table is different from other colors in at least one of the three colors of R, G, and B. 8. The voltage applied to the liquid crystal determined from the output data is a voltage at which the liquid crystal has a transmittance determined by the current field image data after one field period has elapsed. A driving circuit for the liquid crystal display device according to 5, 6, or 7. 9. A field sequential method in which one frame period is divided into a plurality of field periods corresponding to three colors of RGB, and three colors of R, G and B are sequentially switched and displayed in each field period within one frame period. A liquid crystal display device of a system, wherein the liquid crystal has a transmittance corresponding to the current field image after one field period based on the image data of the current field and the image data of the same color one frame before. A drive circuit for a liquid crystal display device that applies an optimum drive voltage to the liquid crystal. 10. A drive circuit for a liquid crystal display device according to claim 9, wherein the optimum drive voltage based on the image data of the current field and the image data of the same color one frame before is provided as a high-speed response data table. 11. The drive circuit for a liquid crystal display device according to claim 10, wherein a data value of the high-speed response data table is different from other colors in at least one of the three colors of R, G, and B.