JP2941580B2 - Display panel driving 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 display panel driving device used for AV (Audio Visual) equipment, OA (Office Automation) equipment, computer terminal equipment with a communication function, and the like.

[0002]

2. Description of the Related Art In recent years, with the development of a highly information-oriented society, a demand for a large-sized display having a large display capacity has been increasing. To respond to such a request,
The development of high-definition CRTs (Cathode Ray Tubes), also known as the "kingdom of displays", is progressing, while the size is up to 40 inches for direct-view and 200 inches for projection. Have been. However, the weight and depth problems of CRTs are large and large.
Since the realization of a large display capacity becomes more serious, a drastic solution is strongly desired.

[0003] Flat-panel displays that perform display based on a principle different from those of conventional CRTs have departed from the current situation used in applications such as word processors and personal computers, and have achieved high display requirements for high-vision and high-performance EWS (engineering workstation) displays. Research is progressing steadily toward quality improvement.

[0004] As the flat panel display, there are ELP (electroluminescent panel), PDP (plasma display panel), VFD (fluorescent display tube), ECD (electrochromic display device), LCD (liquid crystal display device) and the like. Among these, LCDs are regarded as the most promising because of the easiness of realizing full color and the compatibility with LSI (Large Scale Integrated Circuit), and the technological progress is the most remarkable.

There are two types of LCDs: a simple matrix drive type LCD and an active matrix drive type LCD. A simple matrix drive type LCD has a structure in which liquid crystal is sealed in an XY matrix type panel in which a pair of glass substrates are opposed to each other so that striped electrodes formed on each other are orthogonal to each other. The display is performed by utilizing. On the other hand, an active matrix drive type LCD has a structure in which a non-linear element is directly added to a picture element, and performs display by positively utilizing the non-linear characteristics (switching characteristics and the like) of each element. Therefore, as compared with the former simple matrix drive type LCD, a display with less dependence on the display characteristics of the liquid crystal itself and with high contrast and high response can be realized. This type of nonlinear element includes a two-terminal type and a three-terminal type. MIM (metal-insulator-metal), diode, and the like exist as two-terminal nonlinear elements, while TFTs are used as three-terminal nonlinear elements.
(Thin film transistor), Si-MOS (silicon metal oxide semiconductor), SOS (silicon-on-sapphire)
Etc. exist.

However, a simple matrix drive type LC
In the case of D, the manufacturing process is easy and the cost is advantageous because the panel structure is simplified.

In the simple matrix drive type LCD, the ratio of the effective voltage applied to the selected pixel electrode and the non-selected pixel electrode approaches 1 as the number of scanning electrodes increases.
In order to realize high contrast, the display characteristics of the liquid crystal itself need to be steep. In order to obtain this characteristic, the liquid crystal molecules are twisted from about 180 ° to about 270 °, and a so-called STN (Super Twiste) in which a polarizing plate is further combined.
d Nematic) -LCD is usually used.
A STN-LCD incorporating a compensator made of a liquid crystal or a polymer film has also been commercialized.

On the other hand, the response characteristic required for the liquid crystal display device generally has a relation opposite to the contrast characteristic. One of the reasons is known to be caused by the drive waveform. An XY matrix driving method generally used for a simple matrix driving type LCD sequentially selects each scanning electrode one by one and synchronously transmits a signal corresponding to display data to a data electrode crossing the scanning electrode. This is a method of applying voltage to In this method, the voltage applied to each picture element is, as shown in FIG. 3 (a), a high voltage T once in a cycle (frame) in which all the scanning electrodes are turned on.
Is applied, and a constant low bias voltage U is applied at other main times.

FIG. 3B shows a case where a high-speed response type LCD is realized by optimizing the physical property values of the liquid crystal material, particularly the viscosity and the liquid crystal layer thickness in order to shorten the response time. As described above, a phenomenon (hereinafter referred to as a frame response phenomenon) that changes in response to the waveforms of the voltages T and U described above occurs in the transmittance (vertical axis), and the transmittance is represented by a broken line obtained by the cumulative response of the applied voltage. There is a drawback that the value deviates from the normal value shown and the contrast is impaired.

In recent years, the following two driving methods have been proposed to improve the frame response phenomenon. One of the driving methods is to apply a positive or negative voltage derived from a Walsh (Walsh) function to all the scanning electrodes at the same time, and, in synchronization with the application, to correlate with externally input display data. (A so-called active addressing method) in which the applied data signal is applied to the data electrode (TJ Scheffer, eta).
l. SID'92, Digest, p. 228). Another driving method is to apply a positive or negative voltage based on a binary method or a voltage of 0 to a plurality of scan electrodes, and to combine the potential with the potential of the data electrode to display contents and applied voltage. Is applied to all the data electrodes (so-called multiple line simultaneous selection method) (TN Ruckmo).
ngatathan, 1988 IDRC p. 80).

Next, an example of a specific procedure of both methods will be described. In the case of the active addressing method, the operation is performed as follows. First, a scanning-side signal Y ₁ to Y ₅ dot matrix five rows and five columns shown in FIG. 4, is determined using the Walsh function shown in FIG. Specifically, each different in each of the scanning signals Y ₁ to Y ₅ as shown in FIG. 5 (a) 5
One frame period is divided into eight periods t _{1 to} t ₈ , and each scanning-side signal Y _{1 to} Y ₅ is set, as shown in FIG. Is determined.

Next, a data-side signal is obtained. For example, as shown in FIG. 6, taking the second column as an example, first, the display data I _{12 to} I ₅₂ of each dot in the second column are set to ON by −1,
Off expressed in two values of ± 1 +1, subjected to FIGS. 7 (a) to the display data I ₁₂ of which the first line as shown in the first row scanning side signal Y _1. Next, the same calculation is performed for the second to fifth rows. Subsequently, the calculation result of each column obtained as described above is added for each of the periods t _{1 to} t ₈ , and an added value g
Ask for ₂ . 7 (b) is a diagram showing the sum value g ₂ at the voltage level.

The data signal X shown in FIG.
₂ is expressed by multiplying the addition value g ₂ by a coefficient C as shown in the following equation. The coefficient C depends only on the number N of the scanning electrodes, and when N is 5, C ≒ 0.425 Becomes

X ₂ = C · g ₂ where C = [1 / (2 (N−√N))] ^1/2 All scanning side signals Y _{1 to} Y ₅ and data When the side signals X _{1 to} X ₅ are applied simultaneously to perform surface scanning, display data is displayed on the panel. FIG. 8 (b)
At this time, a voltage waveform applied to turn on the third row of the second column shown in FIG. 8 (a) (●) is shown. Similarly, FIG. 8 (c) shows the fourth row of the second column. 3 shows a voltage waveform applied to turn off (○).

Next, a method for simultaneously selecting a plurality of lines will be described. For example, as shown in FIG. 9, a case in which three lines are selected as one set at the same time will be described as an example. First, three scanning electrodes are simultaneously selected, and scanning is performed sequentially by applying a voltage of + Vr or -Vr. Therefore, as the applied scanning voltage,
Three values are required for ± Vr and 0 V when not selected.

Next, on is set to 1 as a display pattern, and of
f is set to 0, + Vr of the scanning electrode is set to 1, and -Vr is set to 0, and an exclusive OR is taken corresponding to the bit,
Determine the voltage of one data electrode. At this time, if the number of lines is M, the data voltage needs a level of (M + 1) in the case of multi-color display.

Next, the scanning voltage and the data voltage determined as described above are simultaneously applied to the first set of lines. From then on, the same voltage is determined in the same manner as before, and the simultaneous scanning is repeatedly performed for each set composed of a plurality of lines. Thereby, the display is performed on the panel.

As can be seen from the above description, in the case of both methods, selection is performed a plurality of times during one frame.
The peak value of the applied voltage during one frame can be changed in a direction in which the peak value is averaged as much as possible, and the frame response phenomenon that occurs in the case of the conventional method of performing one selection during one frame can be improved.

As a specific circuit example, FIG. 10 shows an example of a liquid crystal display device system provided with the above-mentioned active addressing type driving device. This liquid crystal display device system includes an XY matrix type liquid crystal display device 1. The liquid crystal display device 1 includes a liquid crystal layer, and a data electrode 1b and a scanning electrode 1a opposed to each other while sandwiching the liquid crystal layer. For example, the data electrode 1b have 15 present the data side signal X ₁ to X ₁₅ is inputted, the scanning electrodes 1a having fifteen to scan side signal Y ₁ to Y ₁₅ are inputted. The intersection of the scanning electrode 1a and the data electrode 1b is a display dot.

A data electrode drive circuit 4 is connected to the data electrode 1b, and a scan electrode drive circuit 5 is connected to the scan electrode 1a.
Is connected.

The data electrode drive circuit 4 is supplied with an output signal from the orthogonal transform operation circuit 3. The orthogonal transform operation circuit 3 outputs an image data signal, a timing signal, and a scan signal output from the Walsh function generator 2. It is given a signal Y ₁ and the like. Further, the Walsh function generator 2 is provided with a timing signal. On the other hand, the scan electrode drive circuit 5 is supplied with a timing signal and a scan-side signal Y ₁ from the Walsh function generator 2.

The contents of signal processing in the active addressing type driving circuit having such a configuration are as follows. The Walsh function generator 2 obtains positive or negative scanning signals Y _{1 to} Y ₁₅ derived by the Walsh function. This signal is applied to the scan electrode 1a via the scan electrode drive circuit 5. Further, the orthogonal transform operation circuit 3 decomposes the image data signal input from the outside into binary signals of +1 and −1, and converts these signals into scanning signals Y _{1 to} Y given from the Walsh function generator 2. multiplied by _15, followed by the addition value g ₂ calculated as described above, obtaining the data side signal X ₂ is a value obtained by multiplying the coefficient C in the added value g _2. This signal is supplied to the data electrode 1 of the liquid crystal display 1 via the data electrode driving circuit 4.
b. When the voltage application for one frame is completed in this way, the original image is reproduced on the liquid crystal display device 1.

FIG. 11 shows an example of the voltage waveforms (ad) applied to each voltage of the liquid crystal panel and the voltage waveforms (eg) applied to the display dots. In the figure, the vertical axis is the voltage value,
The horizontal axis indicates time. + Vr and -Vr are voltage values of the scan electrode drive circuit, and Vc (t) is an output value of the data electrode drive circuit. Here, the calculation is performed with the display of all the image data turned on.

[0024]

[0007] By the way, Walsh
Function, when the data number L was L = 2 ^r, complete one-dimensional Walsh function system having a period of L, the L number of signals Wal
(M, n) (where m = 0, 1,..., L−1; n = 0,
1, 2,..., L-1). For example, L = 2
^{When 8} = 256, 256 Wal (m, n) corresponds.

This Wal (m, n) is generally defined by the following equation.

Wal (0, n) = 1 (n = 0,1,2, ..., L-1) Wal (1, n) = 1 (n = 0,1,2, ..., (L / 2) -1) or -1 (n = (L / 2), (L /
2) + 1,…, L-1) Wal (m, n) = Wal ([m / 2,2n]) ・ Wal (m-2 [m / 2], n) where [] is a Gaussian symbol , [M / 2].

However, since the number N of scanning electrodes is set to an arbitrary value by the LCD, generally, N ≠ L (2 ^r )
Becomes Therefore, in this case, N Wals are calculated from 2 ^r.
(M, n) is selected and voltage is applied while comparing with display data. However, since the Walsh function system is not perfect, problems such as a decrease in contrast and crosstalk occur, and a desired display can be completely performed. Could not be reproduced.

Further, since a fixed Walsh function voltage is applied to the scan electrodes in a fixed manner, the frequency component of the voltage waveform differs between the scan electrodes, and the above-mentioned frequency varies depending on the capacitance and wiring resistance of the liquid crystal display panel. It appeared as a voltage difference, and crosstalk was occurring.

The present invention has been made to solve such a problem of the prior art, and an object of the present invention is to provide a display panel driving apparatus which is excellent in contrast and free from crosstalk.

[0030]

According to the present invention, there is provided a driving apparatus for a display panel, which comprises a matrix type display panel in which M parallel data electrodes and N parallel scanning electrodes are arranged so as to intersect an orthogonal function. And an orthogonal function generator that generates a number 2 ^r (r: an integer) of orthogonal function sequences smaller than the number N of the scan electrodes , and a 2 ^r orthogonal function from the orthogonal function generator. Input a column and divide one frame period into [N / 2 ^r ] +1 (where [] is
Gauss' notation and a), 2 ^r in each period until [N / 2 ^r]
A signal corresponding to the orthogonal function sequence is applied to the scan electrodes of
/ 2 ^r] +1 th the period and the scanning electrode side drive means for applying a signal corresponding to the orthogonal function sequence to the scanning electrodes 2 ^r including virtual scan electrodes assuming the number of scanning electrodes and 2 ^r , the 2 ^r orthogonal function sequence, enter the M × display data and virtual data other than the display dots regarding display dots N on the display panel, one frame period is divided into [N / 2 ^r] +1, In each period up to [N / 2 ^r ], a voltage based on the display data and the orthogonal function sequence is applied to the data electrode of the display dot having the scanning electrode selected by the scanning electrode driving circuit, and [N / ^r ] In the 2 ^r ] + 1st period, the display dot ｛(2 ^r × (1+ [N / 2 ^r ]) corresponding to the number (2 ^r × (1+ [N / 2 ^r ]) − N) of non-existent scanning electrodes. ) -N)｝
× M, and the data electrode-side drive means for applying a voltage based on the display data and the orthogonal function sequence to the data electrodes of the actual display dots, thereby achieving the above object. Is done.

Further, the N scan electrodes are used for a plurality of scans.
A first electrode group including electrodes and a second electrode group including a plurality of scanning electrodes.
An electrode group, and the one frame
Wherein a voltage corresponding to the orthogonal function sequence of 2 ^r in a period the
When applying to the first electrode group and the second electrode group,
The plurality of voltages included in the first electrode group.
The order of application to the scan electrodes and the voltage to the second electrode
The order of application to the plurality of scan electrodes included in the group is different.
It is preferred that it is. Further, the N scanning electrodes
Is divided into a plurality of electrode groups, and the first frame period
The voltage corresponding to the 2 ^r orthogonal function sequence between the plurality
And the order of application to the electrode group of
In the subsequent second frame period, 2 ^r orthogonal function
The order in which corresponding voltages are applied to the plurality of electrode groups is different.
It is preferable that

[0032]

Function N × L where the number N of scanning electrodes is N ≠ L (2 ^r )
In a matrix LCD having M display dots,
First, 2 ^r complete orthogonal function sequences are selected from a certain orthogonal function system.

By the way, there are a case where the number N of scanning electrodes is small and a case where it is large for 2 ^r orthogonal function rows.

[In the case of N <2 ^r ] Assuming that the number of scanning electrodes is apparently 2 ^r , virtual data is displayed on (2 ^r −N) × M display dots that do not exist. The data electrodes of the existing display dots are corrected for the signal related to the display data and driven. In this case, one frame period is divided into 2 ^r, applied in synchronization with the scanning electrodes in each divided period, a voltage correlated with the orthogonal function to the data electrodes. The maximum voltage ratio applied to the selected display dot and the non-selected display dot, because it becomes ^{√ {(√2 r +1) /} (√2 r -1)}, considering the number of scanning electrodes, 2 ^r Is preferably as close as possible to the number N of scanning electrodes.

[0035] [N> In the case of 2 ^r] In this case,
One frame period is divided based on N / ^2r as follows. At this time, N / 2 ^r = p + a (where p is an integer,
When 0 <a <1), one frame period is divided into p + 1 times.

Next, select the scanning electrodes 2 ^r at each time to p, sequentially selects this as one unit. In this case, scanning may be performed sequentially downward from above the display screen, but may be arbitrarily selected.

Further, half of the voltage width applied to the selected scanning line is applied to the non-selected scanning lines. The data electrodes
A voltage is applied based on the result of arithmetic processing of desired display data and scan electrode data.

Next, during the (p + 1) -th period, 2 ^r (p +
1) Although -N scan electrodes are insufficient, virtual data is imagined in this display area ({ ^2r (p + 1) -N} .times.M), and data corresponding to the virtual data is set to the actual data signal voltage. Is corrected and applied.

According to the above-mentioned method, a desired display can be completely reproduced because all the complete orthogonal function sequences are used.

[0040]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below.

(Embodiment 1) FIG. 1 is a block diagram showing the whole of a liquid crystal display system including a driving device according to this embodiment. The liquid crystal display device system includes a liquid crystal display device 11 for performing display, a data electrode driving circuit 14 and a scanning electrode driving circuit 15 for supplying a signal to the liquid crystal display device 11, and an orthogonal transform operation circuit for supplying a signal to the data electrode driving circuit 14. 13 and an orthogonal function generator 12 that supplies signals to the orthogonal transform operation circuit 13 and the scan electrode drive circuit 15.
In addition, a control signal such as a timing signal, display data, and virtual data are given to the orthogonal transform operation circuit 13,
A control signal such as a timing signal is applied to the orthogonal function generator 12, the data electrode drive circuit 14, and the scan electrode drive circuit 15.

The liquid crystal display device 1 is an STN-LCD having a liquid crystal layer and a data electrode 1b and a scanning electrode 1a opposed to each other while sandwiching the liquid crystal layer. For example, the data electrode 1b have a 320 to data-side signals X ₁ to X ₃₂₀ is applied, the scanning electrodes 1a scanning side signal Y
_{1 to} Y ₂₄₀ are applied. Scanning electrode 1a
The intersection of the data electrode 1b with the display electrode 1b is a display dot.

The data electrode 1b is connected to a data electrode drive circuit 14, and the scan electrode 1a is connected to a scan electrode drive circuit 15.

An output signal from the orthogonal transform operation circuit 13 is supplied to the data electrode drive circuit 14, and the display data signal, the timing signal, and the function signal output from the orthogonal function generator 12 are supplied to the orthogonal transform operation circuit 13. Is given. Further, a timing signal is supplied to the orthogonal function generator 12. On the other hand, the scan electrode drive circuit 15 is supplied with a timing signal and an output signal from the orthogonal function generator 12.

In the display panel driving device configured as described above, signal processing is performed as follows.

As the orthogonal function generator 12, for example, 2 ⁸
= Walsh function consisting of 256 function rows F1 to F256, that is, a function generating a function row of a number larger than the number of scanning electrodes 1a was used. Such a function sequence F1
The scan electrode drive circuit 15 to which F256 to F256 is input divides one frame into 2 ⁸ = 256 small periods, and applies F241 to F256 to a virtual scan electrode that does not exist in each period. Signals corresponding to F1 to F240 were applied to 1a.

The orthogonal transformation operation circuit 13 temporarily takes in display data corresponding to 240 × 320 display dots from a personal computer (not shown) into a built-in memory, and reads out the data sequentially for each picture element row. In this case, ON is set to -1, O
FF is set to 1 and desired display data is set to In, m (1 ≦ n ≦ 2
40, 1 ≦ m ≦ 320) = ± 1. The virtual data is In ′, m (241 ≦ n ′ ≦ 256,1 ≦ m
≦ 320) = 1. Subsequently, the Walsh function sequence Fi (tj) = ± 1 (1 ≦ i ≦ 25)
6, 1 ≦ j ≦ 256) and outputs the obtained result to the data electrode drive circuit 14.

The data electrode drive circuit 14 applies a correction constant C = 0.065 (C = [1 / ｛2 (256-√
In consideration of 256)｝] ^1/2 ), an analog voltage was applied to each data electrode 1b.

In this embodiment performed as described above,
One frame was divided into 256 small periods, the voltage obtained by the above calculation was applied to the scanning / data electrodes in each period in synchronization with each other, and all the polarities of the Walsh function were inverted for each frame. Thereby, it was confirmed that a favorable display with a contrast of 20 and a response speed of 200 ms could be obtained.

In the above embodiment, the signals corresponding to F1 to F240 are fixed and applied to each scanning electrode 1a in a state where F241 to F256 are applied to the virtual scanning electrodes in each period. The present invention is not limited to this, and the signals F1 to F240 corresponding to the respective scanning electrodes are not fixed, and the function sequence is shifted or selected irregularly in each period, and the same operation voltage is obtained. May be applied to the scanning / data electrode. In such a case, it was confirmed that the bias of the frequency component of the voltage applied to each electrode, which would occur when the voltage was fixed and applied, could be prevented, and that the display crosstalk was improved.

(Embodiment 2) As the orthogonal function generator 12, a Walsh consisting of 2 ⁶ = 64 function strings F1 to F64 is used.
The one that generates the function was used. That is, in the second embodiment, unlike the first embodiment, the one that generates a smaller number of function rows F1 to F64 than the number of the scanning electrodes 1a is used.

The scan electrode drive circuit 15 for inputting such a function sequence divides one frame period into four divided periods. First, in the first period, the scan electrodes 1a to which the signals Y1 to Y64 are applied are supplied with F1 to F4. Signals Y1 to Y64 corresponding to F64 were applied. The remaining signals Y65 to Y240 were set to the ground voltage. On the other hand, the orthogonal transformation operation circuit 13 temporarily takes in display data corresponding to 240 × 320 display dots from a personal computer (not shown) into a built-in memory, and sequentially reads out data for each pixel row. In this case, ON is set to -1, OF
F is set to 1 and desired display data is set to In, m (1 ≦ n ≦ 24
0,1 ≦ m ≦ 320) = ± 1. Subsequently, these values are multiplied by the value of each time (tj) of the Walsh function sequence Fi (tj) = ± 1, and the obtained result is output to the data electrode drive circuit 14. The data electrode drive circuit 14 applied an analog voltage to each data electrode 1b in consideration of the input value and a correction constant C = 0.065.

In the next second period, Y65 to Y128
The signals Y65 to Y128 corresponding to F1 to F64 are applied to the scanning electrode 1a to which the signals of the following formulas are applied, and the display dots to which the scanning side signals Y65 to Y128 and the data side signals X1 to X320 are applied to the data electrode 1b. A potential corresponding to data is applied. Thereafter, the same applies to the third period.

In the fourth period, signals Y193 to Y240 applied to scan electrode 1a are signals F1 to F48 corresponding to F1 to F64. The signals applied to the data electrodes 1b are scanning side signals Y193 to Y240 and data side signals X1 to X320.
Is a desired voltage corresponding to the display data of the display dot given. Further, it is assumed that ON display is performed on display dots to which the scanning side signals Y241 to Y256 and the data side signals X1 to X320 are given. The scanning electrode and the data electrode were driven by reflecting the result of this calculation with F1 to F64 on the data potential.

In the case of this embodiment driven in this way, it was found that a good display with a contrast of 18 and a response speed of 180 ms was obtained.

In the second embodiment, the block of the scanning electrode selected for each period is shifted by one block. That is, starting from Y1 in the first period, starting from Y65 in the second period, starting from Y129 in the third period, and starting from Y193 in the fourth period. As a result, it was confirmed that crosstalk could be improved because the selected scanning electrode was different in each period.

In the first and second embodiments, the Walsh function is used as the orthogonal function. However, the present invention is not limited to this function, and the Fourier function, the Haar function, and the Karr function can be used.
A hunen-Loeve function, a Slant function, or the like can be used. In particular, the Slant function is effective in the case of gradation display. FIG. 11 shows an example of the Slant function of 2 ⁴ = 16.

[0058]

If according to the invention as described above, according to the present invention, even when the orthogonal function sequence 2 ^r is the number N and N ≠ 2 ^r of scanning electrodes, with full desired display can reproduce, conventional It is also effective against crosstalk, which has become more problematic, and therefore has good contrast and response speed, and
A display with excellent display uniformity can be provided.

The drive device of the present invention can be widely applied to OA equipment such as personal computers and word processors, video equipment such as televisions, and direct-view and projection displays used for games and the like.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a display panel driving device according to an embodiment.

FIG. 2 shows a display panel driving device according to the present invention in which 2 ⁴ = 1
FIG. 6 is a diagram showing a signal example when the Slant function of No. 6 is used.

FIG. 3 is a diagram for explaining a conventional driving method.

FIG. 4 is a diagram for explaining a conventional active addressing method.

FIG. 5 is a diagram for explaining a conventional active addressing method.

FIG. 6 is a diagram for explaining a conventional active addressing method.

FIG. 7 is a diagram for explaining a conventional active addressing method.

FIG. 8 is a diagram for explaining a conventional active addressing method.

FIG. 9 is a diagram for explaining a conventional multiple line simultaneous driving method.

FIG. 10 is a block diagram showing a liquid crystal display device to which a conventional active addressing method is applied.

11 is a waveform chart of various signals used in the liquid crystal display device of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Liquid crystal display device 11a Scan electrode 11b Data electrode 12 Orthogonal function generator 13 Orthogonal transformation operation circuit 14 Data electrode drive circuit 15 Scan electrode drive circuit

Continued on the front page (72) Inventor Norio Anzai 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inventor Hiroshi Ishii 22-22 Nagaikecho, Abeno-ku, Osaka-shi Osaka Prefecture Inside Sharp Corporation (72 ) Inventor Wataru Nakamura 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (56) References JP-A-6-51276 (JP, A) JP-A-6-4043 (JP, A) (58) ) Surveyed field (Int.Cl. ⁶ , DB name) G02F 1/133 G09G 3/36

Claims (3)

(57) [Claims] 1. A driving device for driving a matrix display panel in which M parallel data electrodes and N parallel scan electrodes intersect with each other by using an orthogonal function. An orthogonal function generator that generates a number 2 ^r (r: integer) of orthogonal function sequences smaller than the number N, and inputs 2 ^r orthogonal function sequences from the orthogonal function generator, and sets one frame period to [N / 2 ^r ] divided into +1 (where [] is the Gauss symbol), 2 in each period until [N / 2 ^{r] r}
A signal corresponding to the orthogonal function sequence is applied to the scan electrodes of
/ 2 ^r] +1 th the period and the scanning electrode side drive means for applying a signal corresponding to the orthogonal function sequence to the scanning electrodes 2 ^r including virtual scan electrodes assuming the number of scanning electrodes and 2 ^r , the 2 ^r orthogonal function sequence, enter the M × display data and virtual data other than the display dots regarding display dots N on the display panel, one frame period is divided into [N / 2 ^r] +1, In each period up to [N / 2 ^r ], a voltage based on the display data and the orthogonal function sequence is applied to the data electrode of the display dot having the scanning electrode selected by the scanning electrode driving circuit, and [N / ^r ] In the 2 ^r ] + 1st period, the display dot ｛(2 ^r × (1+ [N / 2 ^r ]) corresponding to the number (2 ^r × (1+ [N / 2 ^r ]) − N) of non-existent scanning electrodes. ) -N)｝
A driving apparatus for a display panel, comprising: a data electrode side driving unit that applies the virtual data to × M and applies a voltage based on the display data and the orthogonal function sequence to the data electrodes of the actual display dots. 2. The method according to claim 1, wherein the N scanning electrodes include a plurality of scanning electrodes.
Electrode group including a plurality of scan electrodes and a second electrode including a plurality of scan electrodes
And at least one group corresponding to 2 ^r orthogonal function sequences during the one frame period .
Voltage applied to the first electrode group and the second electrode group.
When the voltage is applied, the voltage is included in the first electrode group.
The order and the voltage to be applied to the plurality of scan electrodes
Apply to the plurality of scanning electrodes included in the second electrode group
The display panel driving device according to claim 1 , wherein the order of performing the display panel is different . 3. The method according to claim 1, wherein the N scanning electrodes are divided into a plurality of electrode groups.
Divided 2 in the first frame period ^r Corresponding to the sequence of orthogonal functions
The order in which the voltage is applied to the plurality of electrode groups;
2 in the second frame period following the frame period ^r
To the plurality of electrode groups.
2. The display panel according to claim 1, wherein the display panel performs the display in a different order.
Le drive.