JP3142488B2 - Driving method of simple matrix type liquid crystal display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for driving a simple matrix type liquid crystal display device.

[0002]

2. Description of the Related Art Hitherto, a simple matrix type liquid crystal display device has been driven by a voltage averaging method in which scanning lines are line-sequentially scanned. However, when this method is used for a high-speed response liquid crystal panel, there is a drawback that the ON response is reduced due to the frame response and the contrast is reduced.
To prevent such a decrease in contrast, a driving method has been proposed in which all or a plurality of scanning lines are selected at the same time instead of line-sequential scanning.

A driving method for selecting all or a plurality of scanning lines simultaneously will be described below. Equation 1 is mathematically considered for driving the liquid crystal. Here, X is an image data matrix, and ON is represented by “−1” and OFF is represented by “1”. M is a scanning data matrix, and the selection state is “1” or “−1”
And the non-selected state is represented by “0”. Then, the matrix product Y becomes a signal data matrix.

[0004]

(Equation 1)

However, in order for the signal data to be in a form proportional to the image data, the scanning data matrix M needs to be an orthogonal matrix. Next, each element of the scan data matrix M is represented by m,
Assuming that each element of the image data matrix X is x and each element of the signal data matrix Y is y, the signal data yij of the (i, j) pixel in one frame is represented by Expression 2. Note that N is the total number of rows in the image data matrix, and t is time.

[0006]

(Equation 2)

If the voltage per level of the signal data matrix Y is Vb and k are constants, the scanning-side voltage Vr to the (i, j) pixel in one frame is expressed by the following equation (3).

[0008]

(Equation 3)

The signal side voltage Vc to the (i, j) pixel in one frame is expressed by the following equation (4).

[0010]

(Equation 4)

Using equations (1), (2), (3) and (4),
If the effective voltage Vij applied to the (i, j) pixel is obtained,
become that way.

[0012]

(Equation 5)

In Equation 5, N is an image data matrix X
Is the total number of rows, and S is the number of elements other than “0” in an arbitrary row of the scanning data matrix M (hereinafter, referred to as “simultaneously selected number”).
And t is time. From Equation 5, the image data matrix X
Is “1” or “−1”, the third term of Expression 5 is the total number of rows N of the image data matrix X as shown in Expression 6.
(Constant), and the dependency of the (i, j) image data matrix element xij on the applied effective voltage Vij becomes only the second term of the equation (6).
(I, j) An effective voltage proportional to the image data matrix element xij is applied.

[0014]

(Equation 6)

A driving method for a liquid crystal display device using the above-described conventional driving method for selecting all or a plurality of scanning lines at the same time will be described. FIG. 30 shows a display calculation method in a conventional driving method for selecting all or a plurality of scanning lines at the same time. Reference numeral 101 denotes a scanning data matrix, 102 denotes an image data matrix, 103 denotes a signal data matrix, 104 denotes a signal data maximum value, and 105 denotes an operation order. As an example, 2 obtained by Sylvester expansion
A 56 × 256 order scan data matrix 101 is used.
As the image data matrix 102, a matrix of 256 rows and 2 columns is used.

Here, the Sylvester expansion is expressed by the following equation (7).
Is developed by the Kronecker product expansion as shown in Expression 8, and the above-described scan data matrix M
Is the Kronecker product expansion of S eight times, recursively, as shown in Equation 9.

[0017]

(Equation 7)

[0018]

(Equation 8)

[0019]

(Equation 9)

The operation of the scanning data matrix M and the image data matrix X for obtaining signal data for performing gradation display will be described below with reference to FIG. First, when the number of rows of the image data matrix is n and the number of rows of the scan data matrix is m, (m-n)
A row is added as a dummy row 111. The elements in the dummy rows from the (n + 1) th row to the (m−1) th row are all “−1”. Next, the correction term of each column is calculated. The correction term in each column is 2 of the elements from the first row to (m-1) as shown in Expression 10.
It is represented by the square root of the sum of squares minus m. This correction term is used as an element of the m-th row 112. The image data matrix X ′ and the scanning data matrix M obtained by the above operation are expressed by the following equation (1).
The operation is performed as in 1.

As a result, when Y is applied as signal data to the signal electrodes and M is applied as scanning data to the scanning electrodes, gradation display is performed.

[0022]

(Equation 10)

[0023]

[Equation 11]

[0024]

However, high-quality display cannot always be obtained simply by the condition that the scanning data matrix is an orthogonal matrix. FIG. 32 shows Sylvest.
5 shows the difference in the number of HI / LO switchings of the applied drive voltage waveform between adjacent scan electrodes when a 256 × 256 order scan data matrix generated by expanding er is used. Power loss due to waveform distortion increases in proportion to the number of switching,
Since the liquid crystal element has a property of responding to an effective value, the liquid crystal element responds with a difference in the number of switching as a luminance difference of each scanning line. This luminance difference appears as horizontal streak display unevenness.

For this reason, the effectiveness of the recursive function as a scanning function can be raised, but high-quality display cannot be obtained simply by the condition that the recursive matrix is simply a recursive matrix. FIG. 33 shows a voltage waveform applied to the signal-side electrode when a 256 × 256 order scan data matrix generated by the maximum length sequence coding method is used. As can be seen from FIG. 33, since the frequency component is high,
The influence of differential distortion is large, vertical crosstalk and horizontal streaks are likely to occur, and the frequency response of the waveform envelope is low, so that the influence of the frame response is large and the ON luminance is reduced.

According to the present invention, in order to solve the above-mentioned problems in the prior art, it is possible to reduce vertical crosstalk, reduce horizontal streaks, reduce character crosstalk and reduce frame response, and perform high-quality display. It is an object of the present invention to provide a driving method of a simple matrix type liquid crystal display device which can be performed.

[0027]

According to a first aspect of the present invention, there is provided a driving method of a simple matrix type liquid crystal display device, wherein a signal data matrix is generated by calculating an image data matrix and a scanning data matrix inputted from outside. A method for driving a simple matrix type liquid crystal display device, in which a voltage corresponding to a data matrix is applied to a scanning electrode and a voltage corresponding to a signal data matrix is applied to a signal electrode, the method comprising: When the number of rows is set as the time axis, the first column of the cyclic matrix having a column order larger than the number of scanning lines in the driving unit is replaced with a non-scanning column as a scanning data matrix. Invert the column sign in any column,
The scanning lines are simultaneously driven by using rows in which adjacent rows are replaced so as not to be adjacent to each other again.

In particular, as a scan data matrix, a normal cyclic Hadamard matrix derived by the maximum length sequence coding method, which is obtained by inverting the column sign of one or more arbitrary columns, or a normal cyclic Hadamard matrix derived by the quadratic residue method is used. It is preferable to drive all the scanning lines simultaneously by using a Hadamard matrix obtained by inverting the column sign of one or more arbitrary columns. According to the driving method of the simple matrix type liquid crystal display device of the first aspect, the frequency of the waveform applied to the signal side electrode can be controlled, the crosstalk can be reduced, and the display quality of the liquid crystal display device is impaired. Disappears.

According to a second aspect of the present invention, there is provided a driving method of a simple matrix type liquid crystal display device according to the first aspect, wherein the number of rows is replaced by an arbitrary number that is equal to or less than the square root of N and a divisor of N. When the integer is n, the quotient obtained by dividing the row number by n is q, and the remainder is r, the new row number is q + r × N / n
It is performed so that it becomes. According to the driving method of the simple matrix type liquid crystal display device according to the second aspect, the same effect as the first aspect is obtained.

According to a third aspect of the present invention, there is provided a driving method of a simple matrix type liquid crystal display device, wherein the number of scanning lines in a driving unit is 240, and an image data matrix and a scanning data matrix input from outside are calculated. And applying a voltage corresponding to the scanning data matrix to the scanning electrodes, and applying a voltage corresponding to the signal data matrix to the signal electrodes, comprising: When the scanning direction is set to the order of the scanning lines and the row direction is set to the time axis, the scanning data matrix has a row order of 244 or a multiple of 4 and a column order of 244.
The first column of the normal cyclic matrix that is a multiple of 4 is replaced with a non-scanning column, the column sign is inverted by one or more arbitrary columns, the total number of rows is set to N, and the row number is divided by 4. If the quotient is q and the remainder is r, the new line number is q + r × N / 4
It is characterized by being performed as follows.

In particular, as the scan data matrix, the row order derived by the maximum length sequence coding method is a multiple of 4 equal to or greater than 244, and the column order is a multiple of a multiple of 4 equal to or greater than 244. When one column is replaced with a non-scanning column, the column sign is inverted with one or a plurality of arbitrary columns, and when the total number of rows is N, the entire row is divided into four equal to N / 4 rows,
It is preferable to simultaneously drive all the scanning lines by using the ones that have been replaced so that they are adjacent to each other one by one from each division unit.

The first column of the normal cyclic matrix whose row degree derived by the quadratic residue method is 244 or more and whose column degree is 244 or more is replaced with a non-scanning column as a scanning data matrix. When the sign of the column is inverted for one or a plurality of arbitrary columns and the total number of rows is N, the entire row is divided into four equal parts of N / 4 rows, and the rows are replaced so that one row is adjacent to each division unit. It is preferable to drive all the scanning lines simultaneously by using the above.

According to the driving method of the simple matrix type liquid crystal display device of the third aspect, for example, in a VGA of a dual scan drive, the row degree is a multiple of 4 of 244 or more as a scan data matrix, and Column degree is 2
The first of a normal cyclic matrix that is a multiple of 4 greater than or equal to 44
The column is replaced with a non-scanning column, the column sign is inverted by one or a plurality of arbitrary columns, and when the total number of rows is N, the entire row is divided into N / 4 rows into four equal parts. Simultaneous driving of all scanning lines by using ones that are replaced so that they are adjacent to each other can lower the frequency of the signal side electrode, reduce vertical crosstalk and horizontal streaks, The display quality of the display device is not impaired.

According to a fourth aspect of the present invention, there is provided a driving method of a simple matrix type liquid crystal display device, wherein the number of scanning lines in a driving unit is 240, and an image data matrix and a scanning data matrix inputted from the outside are calculated. And applying a voltage corresponding to the scan data matrix to a scan electrode, and applying a voltage corresponding to the signal data matrix to a signal electrode, the method comprising: When the direction of the number of columns of the matrix is the order of the scanning lines and the direction of the number of rows is the time axis, the scanning data matrix is a multiple of 32 with a row order of 256 or more and 32 rows with a column order of 256 or more. The first column of the normal cyclic matrix which is a multiple is replaced with a non-scanning column, the column sign is inverted by one or more arbitrary columns, the total number of rows is N, and the quotient obtained by dividing the row number by 32 is q When The remainder is taken as r, it is characterized in that the new line number is carried out so as to q + r × N / 32.

In particular, the normal cyclic matrix whose row degree derived by the maximum length sequence coding method is a multiple of 32 equal to or greater than 256 and whose column order is a multiple of 32 equal to or greater than 256 is used as the scan data matrix. Replace one row with a non-scan row,
Furthermore, when the sign of the column is inverted in one or a plurality of arbitrary columns and the total number of rows is N, the entire row is divided into 32 equal parts by N / 32 rows, and each row is adjacent to each other by one row. It is preferable to drive all the scanning lines at the same time by using the line replaced.

The first column of a normal cyclic matrix having a row degree derived by the quadratic residue method, which is a multiple of 32 which is 256 or more, and a column degree which is a multiple of 32 which is 256 or more, is used as a scanning data matrix. Swap with non-scan columns, and 1
Alternatively, when the sign of the column is inverted for a plurality of arbitrary columns and the total number of rows is N, the entire row is divided into 32 equal parts each of N / 32 rows, and the rows are replaced so that each row is adjacent to one row at a time. It is preferable to drive all the scanning lines at the same time.

According to the driving method of the simple matrix type liquid crystal display device of the present invention, for example, in a dual scan drive VGA or the like, the scan data matrix has a row order of 256 or more and a multiple of 32, and When the first column of a normal cyclic matrix whose column degree is a multiple of 32 equal to or greater than 256 is replaced with a non-scanning column, column sign inversion is performed on one or a plurality of arbitrary columns, and when the total number of rows is N, N /
By simultaneously driving all the scanning lines using the 32 rows divided into 32 equal parts and replacing the rows so as to be adjacent to each row one row at a time, the frequency of the signal side electrode is reduced and the frame response is reduced. Can be suppressed, vertical crosstalk and horizontal streaks can be reduced, and the display quality of the liquid crystal display device is not impaired.

According to a fifth aspect of the present invention, there is provided a driving method for a simple matrix type liquid crystal display device, wherein the number of scanning lines in a driving unit is 240, and an image data matrix and a scanning data matrix inputted from the outside are operated to form a signal data matrix. Generating a voltage corresponding to the scan data matrix to a scan electrode, and applying a voltage corresponding to the signal data matrix to a signal electrode. When the number of columns is the order of the scanning lines and the number of rows is the time axis, as a scanning data matrix,
The first column of a normal cyclic matrix whose row degree is a multiple of 4 equal to or greater than 244 and whose column order is a multiple of 4 equal to or greater than 244 is replaced with a non-scanning column, and the column sign is inverted every two columns. , When the total number of rows is N, the quotient obtained by dividing the row number by 4 is q, and the remainder is r, the new row number is set to q + r × N / 4. is there.

In particular, as a scanning data matrix, the row order derived by the maximum length sequence coding method is a multiple of 4 equal to or greater than 244, and the column order is a multiple of 4 equal to or greater than 244. When one column is replaced with a non-scanning column, and the column sign is inverted every two columns, and when the total number of rows is N, the entire row is divided into N / 4 rows and divided into four equal parts.
It is preferable to drive all the scanning lines simultaneously by using the lines which are replaced so that they are adjacent to each other.

The first column of a normal cyclic matrix whose row order is a multiple of 4 equal to or greater than 244 and whose column order is a multiple of 4 equal to or greater than 244 is derived as a scan data matrix. When the number of rows is N, the whole row is N.
It is preferable that all the scanning lines are simultaneously driven by using one that is divided into quarters by / 4 rows and the rows are replaced so that one row is adjacent to each division unit.

According to the driving method of a simple matrix type liquid crystal display device of the present invention, for example, in a dual scan drive VGA or the like, the scan data matrix has a row order of 244 or more and a multiple of 4 and a column. Order is 244
When the first column of the normal cyclic matrix, which is a multiple of 4, is replaced with a non-scanning column, the column sign is inverted every two columns, and when the total number of rows is N, the entire row is N / 4 rows at a time. Divide into four equal parts,
By simultaneously driving all the scanning lines by using the lines that are replaced one by one from each division unit, the frequency of the signal side electrode can be reduced and the character crosstalk can be reduced. The display quality of the device is not impaired.

[0042]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. That is, in the driving method of the simple matrix type liquid crystal display device, a signal data matrix is generated by calculating an externally input image data matrix and scanning data matrix, and a voltage corresponding to the scanning data matrix is applied to the scanning electrodes. In addition, a voltage corresponding to the signal data matrix is applied to the signal electrode.

When the direction of the number of columns of the scanning data matrix is the order of the scanning lines and the direction of the number of rows is the time axis, the scanning data matrix is a cyclic matrix having a column order greater than the number of scanning lines in the driving unit. Replaces the first column with the non-scanning column
Alternatively, scanning lines are simultaneously driven by using a column in which the sign of the column is inverted in a plurality of arbitrary columns and rows are exchanged so that adjacent rows are not scattered so as to be adjacent again.

In the first embodiment, the image data is
0 rows and 640 columns, and the scanning data matrix is 256 rows and 256 columns. In the case of a dual scan type simple matrix type liquid crystal display device, it corresponds to one panel of VGA (640 × 480 dots) size, that is, one of the upper and lower panels. The scanning data matrix in the first embodiment is generated as follows. First, the maximum length sequence coding method (reference "coding theory", Hiroshi Miyagawa et al., Published by Shokodo,
p. 455), a normal cyclic Hadamard matrix whose row degree is a multiple of 4 greater than or equal to 244 and whose column degree is a multiple of 4 greater than or equal to 244, that is, 2 shown in FIG.
A 56th-order normal cyclic Hadamard matrix H is obtained. The maximum length sequence coding method can generate a normal cyclic Hadamard matrix of order 2 k (where k is an integer of 1 or more). However, it cannot always be generated. The Hadamard matrix is a kind of orthogonal matrix, and has a property of being a Hadamard matrix again when two arbitrary rows or columns are exchanged or all elements in an arbitrary row or column are multiplied by −1.

Second, the second column to the 241st column of the matrix H are rearranged in order from the first column to the 240th column, and the first column is rearranged in the 241st column. Get. When the matrix H is used as it is as a scanning data matrix, the elements in the first column are all the same, so that the components become DC components when a scanning signal is applied, and the frequency component difference from other scanning lines increases, resulting in a large luminance difference. Since the direct current component can be retreated to the non-scanning area after the 241, the display unevenness can be prevented. Due to the nature of the Hadamard matrix, the matrix H 'is also a Hadamard matrix.

Third, when the matrix H 'is inverted for each column, a matrix N "shown in Fig. 3 is generated. When the matrix H' is used as it is as a scan data matrix, the elements in the first row are Since they are all the same, the signals applied to the scanning lines when t (time) = 0 are all the same, causing a frame response. However, the sign response of an arbitrary column can prevent the frame response. Also, due to the nature of the Hadamard matrix, the matrix H ″ is a Hadamard matrix. Note that the vertical lines in FIGS. 2 and 3 are generated because the original form of the scanning data matrix is an orthonormal function, and a column in which all elements in one column have the same sign is generated, resulting in a linear shape.

Fourth, when the matrix H ″ is rearranged as shown below, a scan data matrix of this embodiment is generated. The row rearrangement is performed as follows: rows 1 to 256 From 0 to 255, the quotient obtained by dividing the row number p by n (n is an integer) is q, and the remainder is r,
A new rearrangement is made at the position of the line number p 'obtained by the equation (12).
At this time, N = 256. The processing is sequentially repeated from line number 0 to line number 255.

[0048]

(Equation 12)

4 shows a signal-side waveform when displaying an all-white image when H ″ is used as a scanning data matrix.
FIG. 5 shows signal-side waveforms when an all-white image is displayed when the scan data matrix M (2) when n = 2 is used as the scan data matrix. Scan data matrix M when n = 4
FIG. 6 shows a signal-side waveform when an all-white image is displayed when (4) is used as a scanning data matrix. FIG. 7 shows a signal-side waveform when an all-white image is displayed when the scan data matrix M (8) when n = 8 is used as the scan data matrix. n = 1
FIG. 8 shows a signal-side waveform at the time of displaying an all-white image when the scan data matrix M (16) in the case of 6 is used as the scan data matrix. Scan data matrix M when n = 32
FIG. 9 shows a signal-side waveform when an all-white image is displayed when (32) is used as a scanning data matrix. FIG. 10 shows a signal-side waveform when an all-white image is displayed when the scan data matrix M (64) where n = 64 is used as the scan data matrix. Scan data matrix M (12
FIG. 11 shows a signal-side waveform at the time of displaying an all-white image when 8) is used as a scanning data matrix.

FIG. 4 shows that the frequency component of the waveform applied to the signal electrode is a high frequency when the rearrangement by the row division is not performed. On the other hand, when the rearranged M (4) for dividing the row into four is used as the scan data matrix,
It can be seen that the waveform applied to the signal-side electrode during the frame period is lower in frequency than the frequency component of the waveform applied to the signal-side electrode when not divided, that is, when H ″ is used. It is possible to reduce the influence of the waveform distortion on the waveform applied to the scanning electrode, thereby suppressing the fluctuation of the effective value, reducing the vertical and horizontal crosstalk, and increasing the frequency by setting the number of divisions. By adjusting the number of divisions in the row direction in accordance with the row order of the scanning data matrix, crosstalk and frame response can be reduced in a well-balanced manner. be able to.

In the first embodiment, the same effect can be obtained even when column sign inversion is irregularly inverted. Further, as a scanning data matrix, a quadratic remainder method (reference "coding theory", Hiroshi Miyagawa et al., Published by Shokodo, p.
The same effect can be obtained when a matrix obtained by performing column permutation and column sign inversion based on a normal cyclic Hadamard matrix having an order larger than that of the image data matrix generated according to (455-460) is used.

A second embodiment of the present invention will be described with reference to FIGS. That is, in the second embodiment, the image data is 240 rows and 640 columns, and the scanning data matrix is 256 rows and 256 columns. In the case of a dual scan type simple matrix type liquid crystal display device, it corresponds to one VGA size panel, that is, one of the upper and lower panels.

The scanning data matrix M according to the second embodiment is generated as follows. First, using the maximum length sequence coding method (reference "coding theory", Hiroshi Miyagawa et al., Shokodo, p. 455), the row order is a multiple of 4 equal to or greater than 244, and the column order is Is a multiple of 4 greater than or equal to 244, that is, 25 in FIG.
A sixth-order normal cyclic Hadamard matrix H is obtained. The maximum length sequence coding method can generate a normal cyclic Hadamard matrix of order 2 k (where k is an integer of 1 or more). However, it cannot always be generated. The Hadamard matrix is a kind of orthogonal matrix, and has a property of being a Hadamard matrix again when two arbitrary rows or columns are exchanged or all elements in an arbitrary row or column are multiplied by −1.

Second, the second column to the 241st column of the matrix H are rearranged from the first column to the 240th column, respectively, and the first column is rearranged to the 241st column. Get. When the matrix H is used as it is as a scanning data matrix, since the elements in the first column are all the same, they become DC components when a scanning signal is applied, and the frequency component difference from other scanning lines increases, resulting in a large luminance difference. However, since the DC components can be retreated to the non-scanning area after the 241, the display unevenness can be prevented. Due to the nature of the Hadamard matrix, the matrix H 'is also a Hadamard matrix.

Third, when the sign is inverted for each column of the matrix H ', a matrix H "shown in Fig. 14 is generated. When the matrix H' is used as it is as the scan data matrix, the elements in the first row are used. Are the same, the signals applied to the scanning lines are all the same when t (time) = 0, causing a frame response. However, the frame response can be prevented by inverting the sign of an arbitrary column. The matrix H ″ is a Hadamard matrix due to the properties of the Hadamard matrix.

Fourth, when the matrix H ″ is transposed,
The scan data matrix M according to the second embodiment is generated. Line replacement is performed as follows. Total number of rows N = 25
6, the line numbers of the first to 256th lines are from 0 to 255, the quotient obtained by dividing the line number p by the number of divisions n = 4 is q, and the remainder is r.
, A new rearrangement is performed at the position of the row number p ′ obtained by the equation (13). At this time, the total number of rows N = 256 and the number of divisions n = 4
Therefore, rewriting equation 13 results in equation 14.
The processing is sequentially repeated from line number 0 to line number 255.

[0057]

(Equation 13)

[0058]

[Equation 14]

FIG. 15 shows the scanning data matrix M. In addition,
The vertical lines in FIGS. 13 to 15 are generated because the original form of the scanning data matrix is an orthonormal function, and a column in which all the elements in one column have the same sign is generated and becomes linear. 1 when displaying an all-white image when the matrix H ″ is used as the scanning data matrix
FIG. 16 shows the signal-side electrode applied waveform during the frame period. From FIG. 16, it can be seen that the frequency component of the waveform applied to the signal side electrode is a high frequency when the rearrangement by the row division is not performed. On the other hand, when the scan data matrix M is used as the scan data matrix, the signal-side electrode applied waveform in one frame period is shown in FIG.
FIG. From FIG. 17, it can be seen that when the rows are rearranged into four parts, the frequency is lower than the frequency component of the signal-side electrode applied waveform when the rows are not divided, that is, when the matrix H ″ is used. As described above, when the number of divisions in the row direction is 4, the frequency component of the waveform applied to the signal electrode can be reduced, and the influence of the differential distortion of the waveform applied to the signal electrode on the scanning electrode is reduced. As a result, vertical and horizontal crosstalk can be reduced.

The same effect can be obtained when a matrix derived by the quadratic residue method is used as the scanning data matrix.
A third embodiment of the present invention will be described with reference to FIGS. That is, in the third embodiment, the image data is 240 rows and 640 columns, and the scan data matrix is 256
The row has 256 columns. In the case of a dual scan type simple matrix type liquid crystal display device, it corresponds to one VGA size panel, that is, one side of upper and lower panels.

The scanning data matrix M according to the third embodiment is generated as follows. First, the maximum length sequence coding method (reference "coding theory", Hiroshi Miyagawa et al., Published by Shokodo,
p. 455), a normal cyclic Hadamard matrix whose row degree is a multiple of 32 which is 256 or more and whose column degree is a multiple of 32 which is 256 or more, that is, a 256-order normal cyclic form shown in FIG. Obtain the Hadamard matrix H. The maximum length sequence coding method can generate a normal cyclic Hadamard matrix of order 2 k (where k is an integer of 1 or more). However, it cannot always be generated. The Hadamard matrix is a kind of orthogonal matrix, and has a property of being a Hadamard matrix again when two arbitrary rows or columns are exchanged or all elements in an arbitrary row or column are multiplied by −1.

Second, the second column to the 241st column of the matrix H are rearranged from the first column to the 240th column, respectively, and the first column is rearranged to the 241st column, and the matrix H 'shown in FIG. Get. When the matrix H is used as it is as a scanning data matrix, since all the elements in the first column are the same, they become DC components when a scanning signal is applied, and the frequency component difference from other scanning lines increases, resulting in a large luminance difference. However, since the direct current component can be retreated to the non-scanning area after the 241, the display unevenness can be prevented. Due to the nature of the Hadamard matrix, the matrix H 'is also a Hadamard matrix.

Third, when the matrix H 'is inverted for each column, a matrix H "shown in Fig. 20 is generated. When the matrix H' is used as it is as a scan data matrix, the elements in the first row are Since they are all the same, the signals applied to the scanning lines when t (time) = 0 are all the same, causing a frame response.
Frame response can be prevented. The matrix H ″ is a Hadamard matrix due to the properties of the Hadamard matrix.

Fourth, when the rows of the matrix H ″ are replaced, a scan data matrix M according to the third embodiment is generated. The row replacement is performed as follows: the first row having a total number of rows N = 256 The row number of the 256th row from the row is set to 0 to 255, and the row number p
Is divided by the number of divisions n = 32, q is the quotient, and the remainder is r, the row is newly rearranged at the position of the row number p ′ obtained by the equation 15. At this time, since the total number of rows N = 256 and the number of divisions n = 32, Equation 15 can be rewritten as Equation 16. The processing is sequentially repeated from line number 0 to line number 255.

[0065]

(Equation 15)

[0066]

(Equation 16)

FIG. 21 shows the scanning data matrix M. In addition,
The vertical lines in FIG. 19 to FIG. 21 are generated because the original form of the scanning data matrix is an orthonormal function, and a column in which all the elements in one column have the same sign occurs to be linear. 1 when displaying an all-white image when the matrix H ″ is used as the scanning data matrix
FIG. 22 shows the waveform of the signal-side electrode applied during the frame period. From FIG. 22, it can be seen that when the rearrangement by the row division is not performed, the frequency component of the waveform applied to the signal side electrode is a high frequency. On the other hand, when the scan data matrix M is used as the scan data matrix, the signal-side electrode applied waveform for one frame period is shown in FIG.
3 is shown. From FIG. 23, it can be seen that when the row is rearranged into 32, the frequency is lower than the frequency component of the signal-side electrode applied waveform when the row is not divided, that is, when the matrix H ″ is used. Thus, when the number of divisions in the row direction is set to 32, vertical and horizontal crosstalk can be reduced without generating a frame response of liquid crystal response, and vertical and horizontal crosstalk can be reduced while preventing a decrease in luminance. be able to.

The same effect can be obtained when a matrix derived by the quadratic residue method is used as the scanning data matrix.
A fourth embodiment of the present invention will be described with reference to FIGS. That is, in the driving method of this simple matrix type liquid crystal display device, the image data is 240 rows and 640 columns, and the scanning data matrix is 256 rows and 256 columns. In the case of a dual scan type simple matrix type liquid crystal display device, it corresponds to one VGA size panel, that is, one of the upper and lower panels.

The scan data matrix in the fourth embodiment is generated as follows. First, the maximum length sequence coding method (reference "coding theory", Hiroshi Miyagawa et al., Published by Shokodo, p.
455), a normal cyclic Hadamard matrix whose row degree is a multiple of 4 equal to or greater than 244 and whose column order is a multiple of 4 equal to or greater than 244, that is, 25 shown in FIG.
A sixth-order normal cyclic Hadamard matrix H is obtained. The maximum length sequence coding method can generate a normal cyclic Hadamard matrix of order 2 k (where k is an integer of 1 or more). However, it cannot always be generated. The Hadamard matrix is a kind of orthogonal matrix, and has a property of being a Hadamard matrix again when two arbitrary rows or columns are exchanged or all elements in an arbitrary row or column are multiplied by −1.

Second, the second column to the 241st column of the matrix H are rearranged from the first column to the 240th column, respectively, and the first column is rearranged to the 241st column, and the matrix H 'shown in FIG. Get. When the matrix H is used as it is as a scanning data matrix, the elements in the first column are all the same, so that the components become DC components when a scanning signal is applied, and the frequency component difference from other scanning lines increases, resulting in a large luminance difference. Since the direct current component can be retreated to the non-scanning area after the 241, the display unevenness can be prevented. Due to the nature of the Hadamard matrix, the matrix H 'is also a Hadamard matrix.

Third, when the matrix H 'is sign-inverted column by column, a matrix H "shown in FIG. 26 is generated. When the matrix H' is used as it is as a scanning data matrix, the elements in the first row are Since they are all the same, the signals applied to the scanning lines when t (time) = 0 are all the same, causing a frame response, but the frame response can be prevented by inverting the sign of any column. The matrix H ″ is a Hadamard matrix due to the properties of the Hadamard matrix.

Fourth, when the row of the matrix H ″ is replaced, a scan data matrix of the fourth embodiment is generated. The row replacement is performed as follows: The first row of the total number of rows N = 256 , The row number of the 256th row from 0 to 255, the quotient obtained by dividing the row number p by the number of divisions n = 4 is q, and the remainder is r, a new row number is obtained at the position of the row number p ′ obtained by Expression 17. At this time, since the total number of rows N = 256 and the number of divisions n = 4, Equation 17 can be rewritten as Equation 18. The row number 0 to the row number 255 are sequentially repeated.

[0073]

[Equation 17]

[0074]

(Equation 18)

FIG. 27 shows the scanning data matrix M. In addition,
The vertical lines in FIG. 25 to FIG. 27 are generated because the original form of the scanning data matrix is an orthonormal function, and a column in which all the elements in one column have the same sign is generated and becomes linear. 28 shows a signal-side electrode applied waveform in one frame period when the matrix H ″ is used as a scanning data matrix. From FIG. 28, when rearrangement by row division is not performed, the frequency component of the signal-side electrode applied waveform is On the other hand, Fig. 29 shows a signal-side electrode applied waveform in one frame period when the scanning data matrix M is used as the scanning data matrix.
Thus, it can be seen that when the rows are rearranged into four parts, the frequency is lower than the frequency component of the waveform applied to the signal-side electrode when the rows are not divided, that is, when H ″ is used.
This makes it possible to reduce the influence of the distortion of the signal-side electrode applied waveform on the scanning-side electrode applied waveform, suppress the fluctuation of the effective value, and reduce the vertical and horizontal crosstalk.
As described above, when the number of divisions in the row direction is 4, the frequency component of the waveform applied to the signal side electrode can be reduced,
As a result, vertical and horizontal crosstalk can be reduced. Further, since column sign inversion is performed every two columns, character crosstalk caused by a black and white stripe pattern per line can be prevented.

The same effect can be obtained when a matrix derived by the quadratic residue method is used as the scanning data matrix.

[0077]

According to the driving method of the simple matrix type liquid crystal display device according to the first aspect, the frequency of the waveform applied to the signal side electrode can be controlled, the crosstalk can be reduced, and the liquid crystal display device can be controlled. Display quality is not impaired. According to the driving method of the simple matrix type liquid crystal display device according to the second aspect, the same effect as the first aspect is obtained.

According to the driving method of the simple matrix type liquid crystal display device of the third aspect, for example, in a dual scan drive VGA or the like, the row degree is a multiple of 4 of 244 or more as a scan data matrix, and Column degree is 2
The first of a normal cyclic matrix that is a multiple of 4 greater than or equal to 44
The column is replaced with a non-scanning column, the column sign is inverted by one or a plurality of arbitrary columns, and when the total number of rows is N, the entire row is divided into N / 4 rows into four equal parts. Simultaneous driving of all scanning lines by using ones that are replaced so that they are adjacent to each other can lower the frequency of the signal side electrode, reduce vertical crosstalk and horizontal streaks, The display quality of the display device is not impaired.

According to the driving method of the simple matrix type liquid crystal display device of the present invention, for example, in a dual scan drive VGA or the like, the scan data matrix has a row order of 256 or more and a multiple of 32, and When the first column of a normal cyclic matrix whose column degree is a multiple of 32 equal to or greater than 256 is replaced with a non-scanning column, column sign inversion is performed on one or a plurality of arbitrary columns, and when the total number of rows is N, N /
By simultaneously driving all the scanning lines using the 32 rows divided into 32 equal parts and replacing the rows so as to be adjacent to each row one row at a time, the frequency of the signal side electrode is reduced and the frame response is reduced. Can be suppressed, vertical crosstalk and horizontal streaks can be reduced, and the display quality of the liquid crystal display device is not impaired. Claim 5
According to the driving method of the simple matrix type liquid crystal display device,
For example, in a VGA or the like of a dual scan drive, as a scan data matrix, the first column of a normal cyclic matrix whose row degree is a multiple of 4 of 244 or more and whose column order is a multiple of 4 of 244 or more Is replaced with a non-scanning column, the column sign is inverted every two columns, and when the total number of rows is N, the entire row is divided into N / 4 rows and divided into four equal parts.
Simultaneous driving of all scanning lines using the lines that are replaced so that they are adjacent to each other makes it possible to lower the frequency of the signal side electrode and reduce character crosstalk, thereby improving the display quality of the liquid crystal display device. No loss.

[Brief description of the drawings]

FIG. 1 is a diagram showing a normal cyclic Hadamard matrix H that is a source of a scan data matrix M in a method for driving a simple matrix liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating an orthogonal matrix H ′ generated in a process of generating a scan data matrix M in the driving method of the simple matrix liquid crystal display device according to the first embodiment.

FIG. 3 is a diagram illustrating an orthogonal matrix H ″ generated in a process of generating a scan data matrix M in the driving method of the simple matrix liquid crystal display device according to the first embodiment.

FIG. 4 shows a voltage applied to a signal-side electrode when an orthogonal matrix H ″ generated in the process of generating a scan data matrix M in the method for driving a simple matrix liquid crystal display device according to the first embodiment is driven as a scan data matrix. It is a figure showing an example of a waveform.

FIG. 5 is a diagram illustrating an example of a voltage waveform applied to a signal-side electrode when a scan data matrix M (2) is driven as a scan data matrix in the method of driving the simple matrix liquid crystal display device according to the first embodiment. is there.

FIG. 6 is a diagram illustrating an example of a voltage waveform applied to a signal-side electrode when the scan data matrix M (4) is driven as a scan data matrix in the method of driving the simple matrix liquid crystal display device according to the first embodiment. is there.

FIG. 7 is a diagram showing an example of a voltage waveform applied to a signal-side electrode when driving a scan data matrix M (8) as a scan data matrix in the method of driving the simple matrix liquid crystal display device according to the first embodiment. is there.

FIG. 8 is a diagram illustrating an example of a voltage waveform applied to a signal-side electrode when the scan data matrix M (16) is driven as a scan data matrix in the method of driving the simple matrix liquid crystal display device according to the first embodiment. is there.

FIG. 9 is a diagram showing an example of a signal-side electrode applied voltage waveform when the scan data matrix M (32) is driven as a scan data matrix in the method of driving the simple matrix liquid crystal display device according to the first embodiment. is there.

FIG. 10 shows a scan data matrix M (64) of the driving method of the simple matrix type liquid crystal display device according to the first embodiment.
FIG. 9 is a diagram showing an example of a voltage waveform applied to a signal-side electrode when driving as a scanning data matrix.

FIG. 11 shows a scanning data matrix M (12) in the driving method of the simple matrix type liquid crystal display device according to the first embodiment.
FIG. 11 is a diagram showing an example of a voltage waveform applied to a signal-side electrode when driving 8) as a scanning data matrix.

FIG. 12 is a diagram illustrating a normal cyclic Hadamard matrix H that is a source of a scan data matrix M in the driving method of the simple matrix liquid crystal display device according to the second embodiment.

FIG. 13 is a diagram illustrating an orthogonal matrix H ′ generated in a process of generating a scan data matrix M in the driving method of the simple matrix liquid crystal display device according to the second embodiment.

FIG. 14 is a diagram illustrating an orthogonal matrix H ″ generated in a process of generating a scan data matrix M in the driving method of the simple matrix liquid crystal display device according to the second embodiment.

FIG. 15 is a diagram showing a scan data matrix M in the driving method of the simple matrix type liquid crystal display device according to the second embodiment.

FIG. 16 shows a voltage applied to a signal-side electrode when an orthogonal matrix H ″ generated in a process of generating a scan data matrix M in the method for driving a simple matrix liquid crystal display device according to the second embodiment is used as a scan data matrix. It is a figure showing an example of a waveform.

FIG. 17 is a diagram illustrating an example of a voltage waveform applied to a signal-side electrode when a scan data matrix M is driven as a scan data matrix in the method for driving a simple matrix liquid crystal display device according to the second embodiment.

FIG. 18 is a diagram illustrating a normal cyclic Hadamard matrix H that is a source of a scan data matrix M in the driving method of the simple matrix liquid crystal display device according to the third embodiment.

FIG. 19 is a diagram illustrating an orthogonal matrix H ′ generated in a process of generating a scan data matrix M in the driving method of the simple matrix liquid crystal display device according to the third embodiment.

FIG. 20 is a diagram illustrating an orthogonal matrix H ″ generated in a process of generating a scan data matrix M in the driving method of the simple matrix liquid crystal display device according to the third embodiment.

FIG. 21 is a diagram illustrating a scan data matrix M in a method for driving a simple matrix liquid crystal display device according to the third embodiment.

FIG. 22 shows a voltage applied to a signal-side electrode when an orthogonal matrix H ″ generated in the process of generating a scan data matrix M in the method of driving a simple matrix liquid crystal display device according to the third embodiment is used as a scan data matrix. It is a figure showing an example of a waveform.

FIG. 23 is a diagram illustrating an example of a signal-side electrode applied voltage waveform when a scan data matrix M is driven as a scan data matrix in the method of driving the simple matrix liquid crystal display device according to the third embodiment.

FIG. 24 is a diagram illustrating a normal cyclic Hadamard matrix H that is a source of a scan data matrix M in the driving method of the simple matrix liquid crystal display device according to the fourth embodiment.

FIG. 25 is a diagram illustrating an orthogonal matrix H ′ generated in a process of generating a scan data matrix M in the driving method of the simple matrix liquid crystal display device according to the fourth embodiment.

FIG. 26 is a diagram illustrating an orthogonal matrix H ″ generated in a process of generating a scan data matrix M in the method of driving the simple matrix liquid crystal display device according to the fourth embodiment.

FIG. 27 is a diagram illustrating a scan data matrix M in a method for driving a simple matrix liquid crystal display device according to a fourth embodiment.

FIG. 28 is a diagram illustrating a voltage applied to a signal-side electrode when an orthogonal matrix H ″ generated in a process of generating a scan data matrix M in the method for driving a simple matrix liquid crystal display device according to the fourth embodiment is used as a scan data matrix. It is a figure showing an example of a waveform.

FIG. 29 is a diagram illustrating an example of a signal-side electrode applied voltage waveform when the scan data matrix M is driven as a scan data matrix in the method of driving the simple matrix liquid crystal display device according to the fourth embodiment.

FIG. 30 is a diagram illustrating a driving method of a conventional simple matrix type liquid crystal display device.

FIG. 31 is a diagram showing insertion of a correction term for gradation display in a conventional example.

FIG. 32 shows a driving waveform HI / LO between adjacent scanning lines in a conventional example.
FIG. 6 is a diagram showing a difference in the number of times of switching.

FIG. 33 is a diagram showing an example of a voltage waveform applied to a signal-side electrode in a conventional example.

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takeshi Okuno 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-8-160389 (JP, A) JP-A-9- 101505 (JP, A) JP-A-9-211420 (JP, A) JP-A-6-347751 (JP, A) JP-A 8-76725 (JP, A) JP-A 7-140931 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G02F 1/133 545 G09G 3/36

Claims (5)

(57) [Claims] An image data matrix and a scanning data matrix input from outside are operated to generate a signal data matrix,
A method for driving a simple matrix type liquid crystal display device, wherein a voltage corresponding to the scan data matrix is applied to a scan electrode, and a voltage corresponding to the signal data matrix is applied to a signal electrode, comprising: In the case where the direction is the order of the scanning lines and the direction of the number of rows is the time axis, the first column of the cyclic matrix having a column order larger than the number of scanning lines in the driving unit is replaced with a non-scanning column as the scanning data matrix. Column inversion in one or more arbitrary columns,
A driving method of a simple matrix type liquid crystal display device, wherein scanning lines are simultaneously driven by using rows which are replaced so that adjacent rows are not scattered next to each other. 2. A method according to claim 1, wherein the total number of rows is N, and any integer less than or equal to the square root of N and a divisor of N is n.
2. The driving method for a simple matrix type liquid crystal display device according to claim 1, wherein the quotient obtained by dividing the row number by n is q and the remainder is r, so that the new row number is q + r × N / n. 3. The number of scanning lines in a driving unit is 240. An image data matrix and a scanning data matrix input from the outside are operated to generate a signal data matrix, and a voltage corresponding to the scanning data matrix is scanned. A method for driving a simple matrix type liquid crystal display device, wherein a voltage corresponding to the signal data matrix is applied to a signal electrode while applying the voltage to the electrode, wherein the direction of the number of columns of the scanning data matrix is set to the order of the scanning line, and When the number direction is the time axis, the first column of a normal cyclic matrix whose row order is a multiple of 4 greater than 244 and whose column order is a multiple of 4 greater than 244 is defined as a scan data matrix. Replace with non-scan row, 1
Alternatively, the column sign is inverted for a plurality of arbitrary columns, the total number of rows is N, the quotient obtained by dividing the row number by 4 is q, and the remainder is r, and the new row number is q + r × N / 4. A method of driving a simple matrix type liquid crystal display device, characterized in that the method is performed as follows. 4. The number of scanning lines in a driving unit is 240, a signal data matrix is generated by calculating an image data matrix and a scanning data matrix input from the outside, and a voltage corresponding to the scanning data matrix is scanned. A method for driving a simple matrix type liquid crystal display device, wherein a voltage corresponding to the signal data matrix is applied to a signal electrode while applying the voltage to the electrode, wherein the direction of the number of columns of the scanning data matrix is set to the order of the scanning line, and When the number direction is the time axis, the first column of a normal cyclic matrix whose row order is a multiple of 32 which is 256 or more and whose column order is a multiple of 32 which is 256 or more is used as a scan data matrix. When the column sign is inverted with one or more arbitrary columns, the total number of rows is N, the quotient obtained by dividing the row number by 32 is q, and the remainder is r, the new row number is q + r × N / 32 The driving method of a simple matrix type liquid crystal display device, characterized in that which is performed so that. 5. The scanning line number of the driving unit is 240, a signal data matrix is generated by calculating an image data matrix and a scanning data matrix input from the outside, and a voltage corresponding to the scanning data matrix is scanned. A method for driving a simple matrix type liquid crystal display device, wherein a voltage corresponding to the signal data matrix is applied to a signal electrode while applying the voltage to the electrode, wherein the direction of the number of columns of the scanning data matrix is set to the order of the scanning line, and When the number direction is the time axis, the first column of a normal cyclic matrix whose row order is a multiple of 4 greater than 244 and whose column order is a multiple of 4 greater than 244 is defined as a scan data matrix. Replace with non-scan row, 2
When the column sign is inverted for each column, the total number of rows is N, the quotient obtained by dividing the row number by 4 is q, and the remainder is r, the new row number is q
+ R × N / 4. A method of driving a simple matrix type liquid crystal display device.