JP3004838B2 - 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 display device used for an image information processing apparatus such as a television receiver, a computer terminal, and a video camera viewfinder, and more particularly, to a flat panel display having scanning lines and information signal lines. The present invention relates to a display device.

[0002]

2. Description of the Related Art As flat display devices, there are a device using an electron-emitting device for each pixel and a device using a liquid crystal cell for each pixel.

In particular, a liquid crystal display device using a liquid crystal has been widely spread and attracted attention. Hereinafter, a display device having a liquid crystal cell as a pixel will be described as an example for easy understanding.

Conventionally, well-known display devices include:
A liquid crystal compound is filled between a scanning line (scanning electrode group) and an information signal line (signal electrode group) constituting a matrix electrode, and a large number of pixels are formed to display image information.
As a driving method of this display device, time division driving in which an address signal is sequentially and selectively applied to a scanning electrode group and a predetermined information signal is selectively applied to a signal electrode group in parallel in synchronization with the address signal is employed. Has been adopted.

[0005] This driving method includes a non-interlaced scanning method in which a scanning signal is sequentially selected from the end electrodes of a scanning electrode group, a two-interlaced scanning method in which every other electrode is skipped, and a European method. Patent specification 3
No. 16774, proposed by Mihara et al. In an N-interlace scanning method in which interlacing is selected every two or more lines (N = 3,
4,5 ...). Above all, in a display device in which it is necessary to increase the selection time of one scan electrode, 2 ⁿ (n = 1, 2) in order to suppress flicker caused by scan drive at a low field frequency and from the convenience of a scan system.
2,3, 2 ⁿ interlaced scanning scheme of selecting every integer) of ... is widely used.

[0006]

[Problems to be solved by the invention]

In general, a display apparatus frequently uses a repetitive image every 2 ⁿ (n = 1, 2, 3,...) For convenience of a graphic system. In that case, 2 ⁿ
If scanning is performed interlacedly, white signals may be periodically repeated, and flicker may occur.

If the field frequency is increased by increasing the degree of interlace to suppress flicker, the visibility of a moving image (moving image) may be reduced.

A display device using a method of skipping (skipping) a predetermined number of scanning electrodes and sequentially selecting the scanning electrodes in order to suppress the occurrence of flicker and improve the visibility of a moving image is disclosed by the inventor Katakura. "Display device (DISP)
No. 5,172,105, entitled "LAY APPARATUS".

On the other hand, in order to display a complicated image satisfactorily and prevent deterioration of the image due to temperature characteristics, it is sometimes necessary to adopt a method of scanning one by one without skipping the scanning electrodes. is there.

It is difficult to directly apply the method disclosed in the above-mentioned US Patent to such a method.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-described problems, and suppresses the occurrence of flicker, improves the visibility of a moving image, and sequentially scans adjacent scanning lines. It is an object of the present invention to provide a display device which employs a versatile display method applicable to a scanning method.

To achieve the above object, a display device of the present invention comprises a matrix having a scanning line group and an information signal line group intersecting the scanning line group, a pixel provided at an intersection of the matrix, Means for supplying a drive signal for causing the pixels to perform display on the matrix, wherein the scanning line group is composed of at least four or more blocks composed of a plurality of adjacent scanning lines. , Said means,
The four or more blocks are sequentially selected so that two adjacent blocks are not successively selected during one vertical scan in one frame, and a plurality of adjacent scan lines are sequentially scanned in the selected block. Scanning means is provided. In this configuration, instead of applying a selection signal while skipping a fixed number of scanning lines from the beginning to the end during one vertical scan as in the conventional case, an interval of at least one block or more is provided during one vertical scan. Since the blocks are scanned, that is, block interlace scanning is performed, even when a so-called repetitive image in which white and black are repeated in the direction of the information electrodes is displayed, the scanning lines are line-sequential within one block. Until the scanning is completed, the black information signal and the white information signal are switched. Therefore, a decrease in the frequency at which the black and white information signals are exchanged is suppressed, and the occurrence of flicker is prevented. In addition, since non-interlace scanning is performed in each block, the visibility of a moving image is maintained.

The display method according to the present invention further comprises a matrix having a scanning line group and an information signal line group intersecting the scanning line group; a pixel provided at an intersection of the matrix; And a means for supplying a drive signal for performing display. In a display method for performing display using a display device, the scan line group includes at least four or more adjacent scan lines. The four or more blocks are sequentially selected so that two adjacent blocks are not continuously selected during one vertical scan in one frame, and a plurality of adjacent scan lines are selected in the selected block. Are sequentially scanned to perform display.

Hereinafter, the basic configuration of the present invention will be described with reference to FIG.

FIG. 1 is a circuit diagram illustrating a display device.
In this figure, as an example, one block (BK1, B
K2 ... BK4) have four adjacent scanning lines
16 scanning lines (C 11 ... C 14, C 21 ...
・ C 24, C31 ... C34, C 41 ... C 44)
Of the display unit DPU.

CELij is a unit pixel, and a scanning signal applying circuit 10 as scanning signal applying means is applied to a corresponding scanning line.
2 and a corresponding information signal line (Sl.
.. Sm) to provide display information (optical information) to which two signals (to a pixel) and a signal supplied from the information signal applying circuit 103 as information signal applying means are applied.

In the display device having such a configuration, FIG.
As shown in the timing chart, the block BK1 is selected, and the scanning lines are sequentially scanned from C11 to C14. Next, not the block BK2 but the block BK3 is selected, and the scanning lines C31 to C34 are sequentially scanned. Then, after selecting the block BK2 and sequentially scanning the scanning lines C21 to C24, the block BK4 is selected and scanning the scanning lines C41 to C44. That is, regular or irregular interlaced scanning is performed between blocks, and non-interlaced scanning is performed within a block.

Such scanning is repeated to display moving images and still images on the display unit DPU.

In FIG. 2, the scanning signal is shown by a simple rectangular wave for the sake of simplicity. However, the present invention is not limited to this, and a scanning signal having an appropriate waveform is used according to the configuration of the pixel. Of course, such a scanning signal may include a reset signal component (clear signal component) for temporarily resetting the display state of the pixel. An auxiliary signal component for stabilizing the electrical or physical characteristics of the pixel without changing the display state may be included. Accordingly, the timing of signals applied to adjacent scanning lines in one block is shown in FIG.
As described above, the fall of one signal may completely coincide with the rise of the next signal, or may be shifted at predetermined intervals.

Alternatively, they may partially overlap. Specifically, when a signal component for display is applied to one scanning line, high-speed display can be performed by applying a reset signal component to the next scanning line. The number of scanning lines selected in each block does not always need to be one,
Scanning for simultaneously selecting a plurality of adjacent scanning lines can be sequentially performed.

That is, taking FIG. 1 as an example,
First, two adjacent scanning lines C11 and C12 are simultaneously selected, that is, scanning signals are simultaneously applied. Next, scan lines C13 and C13
14 are selected at the same time, C31 and C32 are simultaneously selected in the next block BK3, and then C33 and C3 are selected.
4 are simultaneously selected. Thereafter, one frame is displayed in this manner.

As described above, when a plurality of scanning lines are simultaneously selected, two pixels CELi, CELi,
Display can be performed with j, CELi + 1, j as one unit pixel. In this case, one pixel, for example, CELi, J
Is a reference pixel, and CELi + 1, j is a compensation pixel. When the display state of the reference pixel fluctuates due to changes in environmental conditions such as temperature and differs from the true display state, the pixels CELi + 1, j are compensated for the fluctuation. To display. Such a method is suitable for forming a light-transmitting region and a light-blocking region in a unit pixel and changing the ratio of these regions to perform gradation display.

As the pixel used in the present invention, a liquid crystal cell typified by a simple matrix display panel, a light emitting cell including an electron emitting element, or a liquid crystal cell including a thin film transistor or an MIM element as a switching element is preferably used.

In particular, a liquid crystal cell can be manufactured at a low cost, and a twisted nematic liquid crystal and a ferroelectric liquid crystal represented by a material described later are preferably used.

When the display unit is of a translucent type,
By arranging a light source as an illumination means on one surface side, the contrast and the luminance can be improved.

Further, recording means for recording the display image can be provided. Magnetic media, optical media,
There are a semiconductor memory, paper, a plastic sheet and the like, and as a recording means, there are a magnetic head, an optical head, a thermal head, an ink jet head and the like.

The display method is excellent in response,
A gradation display method using a ferroelectric liquid crystal with a wide viewing angle is desirable for displaying a good image.

Here, a gradation display method using FLC will be described. The gradation display method is disclosed in U.S. Pat. No. 4,712,877 to Okada et al., U.S. Pat. No. 4,747,671 to Takahashi et al., And U.S. Pat. No. 4,763,994.

In detail, when the gradation display method is classified, a method of dividing and driving pixels independently (dither method), a method of generating a potential gradient in a pixel to divide a display region (potential gradient method), A method in which a unidirectional electric field is applied to the liquid crystal in a monostable state and the displacement of the liquid crystal molecules in the major axis direction is controlled by the electric field strength, and by changing the thickness of the liquid crystal layer in the pixel, the liquid crystal layer is applied to the liquid crystal layer. A typical example is a method of performing gradation display by changing the intensity of an applied electric field.

However, in the gray scale display method using FLC, the fluctuation of the threshold value due to the temperature change is large as a property of the FLC, and it is difficult to maintain the same gray scale level due to the temperature change. In order to solve this problem, the present inventors have made a serial number 984 on December 2, 1993.
No. 694, "Liquid crystal di
He filed a U.S. application entitled "spray apparatus" and proposed a driving method called "pixel shift method (two-pulse method)". An outline of this driving method will be described. Writing is performed by line-sequential scanning from the first scanning line to the n-th scanning line. At that time, two continuous scanning lines L
And the (L + 1) th are simultaneously selected and written. here,
L is an integer, and 1 ≦ L ≦ n. At the next selection timing, one scanning line is shifted and the (L + 1) th and L +
The second two scanning lines are simultaneously selected. Of the two scanning lines L-th and L + 1-th simultaneously selected, L is L +
1 is a scanning line for temperature compensation. This means that writing is performed only on the scanning line L + 1 when the liquid crystal cell is at the reference temperature, and writing is performed on the scanning line L when the temperature changes. That is, the gradation information originally displayed on the scanning line L + 1 moves on the scanning line L with the temperature fluctuation.

That is, an undesired display state of a pixel on one of at least two adjacent scanning lines is compensated for by a display state of a pixel on the other scanning line. That is, the combined display state of adjacent pixels on at least two scanning lines on the same signal line is used as one unit for gradation display. In this way, any desired display state of one pixel of the unit can be supplemented by the display state of the other pixel, and a normal display can be performed as a whole.

In order to realize such a write operation, specifically, the following conditions are set. The scanning signals input to the two scanning lines selected at the same time are made different. They are determined so that the threshold values of two pixels existing at the intersection of the information signal line and the two scanning lines are continuous. “The threshold value becomes continuous” is a condition for performing a smooth shift of information between two scanning lines sequentially written by line sequential scanning. It is necessary that the distribution of the threshold value for the transmittance is present in the pixel.

However, in such a driving method, the pixel information moves at the position due to the temperature fluctuation.
It is difficult to display the frame image completely. That is,
The pixels on the first scanning line have no moving scanning line, and the n-th scanning line has not been processed after the pixel information is moved due to the temperature fluctuation.

Second, line-sequential scanning is performed from the first scanning line to n.
It must be performed sequentially up to the first time, and interless scanning cannot be performed.

In short, the present invention can be suitably used for suppressing flicker which is likely to occur when performing the above-described gradation driving.

[0037]

【Example】

(Embodiment 1) FIG. 3 is a block diagram showing a configuration of a liquid crystal display device according to a first embodiment of the present invention. In the figure,
107 is a graphic controller, 105 is a drive control circuit, 104 is a scanning signal control circuit, 106 is an information signal control circuit, 102 is a scanning signal application circuit, 103 is an information signal application circuit, and 101 is a liquid crystal display unit. Data sent from the graphic controller 107 enters the scanning signal control circuit 104 and the information signal control circuit 106 through the drive control circuit 105, and is converted into address data and display data, respectively. Then, the scanning signal application circuit 102 generates a scanning signal in accordance with the address data, and the liquid crystal display unit 1
01 is applied to the scanning electrode. Further, the information signal application circuit 103 generates an information signal according to the display data and applies the information signal to the information electrode of the liquid crystal display unit 101.

FIG. 4 is an enlarged view of the liquid crystal display unit 101.
In the figure, C1 to C6 are scanning electrodes, S1 to S6 are information electrodes, and these constitute a matrix electrode. Each electrode group is arranged so as to form a matrix-shaped pixel at an intersection of each other. Although only six electrode groups are shown in FIG.
There are 12 and 1280 information electrodes. P22 is a pixel formed at the intersection of the scanning electrode C2 and the information electrode S2 and serving as a display unit. FIG. 5 is an AA sectional view of FIG. In the figure, reference numeral 301 denotes an analyzer, and 305, a polarizer, which are arranged in crossed Nicols. 302 and 304 are glass substrates, 303 is a ferroelectric liquid crystal, and 306 is a spacer.

In the cell structure shown in FIGS. 4 and 5, a pair of substrates 302 and 304 made of a glass plate or a plastic plate or the like are opposed to each other while being held at a predetermined interval by a spacer 306, and a liquid crystal is interposed between the pair of substrates. Has a cell structure in which a pair of substrates is adhered with an adhesive in order to enclose the cells. However,
FIG. 4 shows only an electrode pattern for convenience. Further, substrate 3
An electrode group including a plurality of transparent electrodes C <b> 1 to C <b> 6 (common electrode group for applying a scanning voltage in the matrix electrode structure) is formed on the electrode 04 in a predetermined pattern such as a strip pattern. On the substrate 302, the transparent electrode C1 described above is provided.
An electrode group (for example, a segment electrode group for applying a signal voltage in a matrix electrode group structure) including a plurality of transparent electrodes S1 to S6 that intersects with C6.

The liquid crystal transparent electrodes C1 to C6 and S1 to S6
May be arranged on the substrates 304 and 302 on which are formed, respectively. Also, the substrates 302 and 3
An insulating film (not shown) for preventing short-circuit and an orientation control film (not shown) may be disposed on each of the elements 04. Examples of the alignment film control film include inorganic insulating materials such as silicon monoxide, silicon dioxide, aluminum oxide, zirconia, magnesium fluoride, cerium oxide, cerium fluoride, silicon nitride, silicon carbide, and boron nitride, and polyvinyl alcohol. A film was formed using an organic insulating material such as polyimide, polyamide imide, polyester imide, polyparaxylene, polyester, polycarbonate, polyvinyl acetal, polyvinyl chloride, polyamide, polystyrene, cellulose resin, melamine resin, urea resin, and acrylic resin. Can be used. The above-mentioned film of an inorganic insulating material can also function as an insulator film for preventing short circuit.

The orientation control film is formed by coating the above-mentioned inorganic insulating material or organic insulating material, and then rubbing (rubbing) the surface thereof in one direction with velvet, cloth or paper to form a uniaxial orientation axis. Is given.

The insulating film for preventing short circuit is 200Å
A thickness of at least 500, preferably at least 500 mm,
SiO ₂ , TiO ₂ , Al ₂ O ₃ , Si ₃ N ₄ , BaT
It is obtained by forming a film of an inorganic insulating material such as iO ₃ . As a film formation method, a sputtering method, an ion beam evaporation method, a method of firing a coating film of an organic titanium compound, an organic silane compound, or an organic aluminum compound, or the like can be used. At that time, as the organic titanium compound, alkyl (methyl, ethyl, propyl, butyl, etc.), titanate compound, and as the organic silane compound,
An ordinary silane coupling agent or the like can be used. When the film thickness of the short-circuit preventing insulator film is 200 ° or less, a sufficient short-circuit preventing effect cannot be obtained. When the film thickness is 5000 ° or more, an effective voltage applied to the liquid crystal layer is not applied. 5000 ° or less, preferably 2000 ° or less.

As a particularly suitable liquid crystal material, a chiral smectic liquid crystal having ferroelectricity is used. Specifically, chiral smectic C phase (SmC *), chiral smectic G phase (SmC *)
mG *), chiral smectic F phase (SmF *),
A liquid crystal having a chiral smectic I phase (SmI *) or a chiral smectic H phase (SmH *) can be used.

For details of the ferroelectric liquid crystal, see, for example, “LE JOURNAL DE PHYSIQUEL
ETTERS "36 (L-69) 1975," F
erroelectric Liquid Cryst
als ";" AppliedPhysic Lett.
ers "36 (11) 1980" SubmicroS
second Bi-stable Electroloop
tic Switching in Liquid C
rystals ";" Solid State Physics "16 (141) 198
1 “Liquid crystal”, US Pat. No. 4,561,726, US Pat. No. 4,589,969, US Pat.
No. 92,858; U.S. Pat. No. 4,596,667; U.S. Pat. No. 4,613,209; U.S. Pat. No. 4,614,609; U.S. Pat.
No. 165, for example, and the present invention can use the ferroelectric liquid crystal disclosed therein.

Specific examples of the ferroelectric liquid crystal compound include desyloxybenzylidene-p'-amino-2-methylbutylcinnamate (DOBAMBC) and hexyloxybenzylidene-p'-amino-2-chloropropylcinnamate ( HOBACPC), 4-o- (2-methyl) butylresorsilidene-4'-octylaniline (MBR
8).

The selection time per scanning electrode is 96 μs.
In the case of ec, the frame frequency is 1 / (512 × 96 μs
ec) = 20.3 Hz. In this display device, when the field frequency is 40 Hz or more, flicker caused by scanning drive can be suppressed, so that the entire screen is constituted by two vertical scans.

As shown in FIG. 6, 512 scanning electrodes are used for one screen.
6 blocks B1 to B16, and in the first field, blocks B1, B3, B5, B7, B9, B11, B1
3, B15, and in the second field, block B
2, B4, B6, B8, B10, B12, B14, B1
Select 6. Then, non-interlace scanning is performed in each block. 1, 2, 3, ... in order from the whole
..., 31, 32, 65, 66, ..., 96, 129,
130, ..., 160, ..., 449, 450, ...
..Selection of the 480th scan electrode to complete the first vertical scan, followed by 33,34,35, ..., 63,6
4,97,98, ..., 128,161,162, ...
.., 192, ..., 481,482, ... 512
The second scanning is completed by selecting the first scanning electrode, and the entire screen is written.

To realize this method, a memory 500 is provided in the scanning signal control circuit 104 as shown in FIG. In the figure, M1 is a scanning address memory, M2 is an address increment memory, M3 is a number counter memory, M4 is a block number counter memory, and MT (1) to MT (16) are address table memories. 1 is set as a fixed value in the address increment memory M2, and the address table memories MT (1) to MT (1) to M
1,65,129,193,257,3 in T (16)
21, 385, 449, 33, 97, 161, 225,
The scan addresses (the positions of the scan electrodes) to be selected first in each of the 16 blocks 289, 353, 417, and 481 are set in the order of the first vertical scan and the second vertical scan. Keep it. Here, the content of the scan address memory M1 means a scan address. Address increment memory M
2 means how many lines are interlaced. The contents of the number counter memory M3 indicate the number of scans in each block. The contents of the block number counter memory M4 indicate what block is being scanned through the first vertical scan and the second vertical scan. The contents of the address table memory MT mean a scanning address to be scanned first in each block.

FIG. 8 is a flowchart showing an algorithm for determining a scanning address. Step 1 is 1
This is a step of initializing the content of the block number counter memory M4 by adding 1 to scan the second block. Step 2 is a step for checking whether or not the content of the block number counter memory M4 is larger than 16 (M4> 16) in order to determine whether or not the writing of all blocks is completed. In step 3, initialization for scanning the inside of the block is performed. First, since the inside of the block is scanned for the first time, 1 is entered in the number counter memory M3. Next, in order to determine the first scan address of the block to be scanned this time, the number of the block is known from the contents of the block number counter memory M4, and the scan address to be scanned first in that block is checked in the address table memory MT. It is stored in the scanning address memory M1. Step 4 is a step of increasing the contents of the block number counter memory M4 by one. Step 5
Indicates that the content of the number counter memory M3 is larger than 32 (M3> 3
2) This is the step of checking whether Step 6 is a step of transferring the scan address. Step 7 is a step of adding the contents of the address increment memory M2 to the contents of the scan address memory M1 and increasing the contents of the number counter memory M3 by one in order to determine the next scan address in the block.

As described above, in the algorithm shown in FIG. 8, the contents of the address table memory MT are stored in the scan address memory M1 using the contents of the block number counter memory M4 as an argument.
The scan address is sent to the scan signal applying circuit 102 16 times, and the process of increasing the contents of the scan address memory M1 by the contents 1 of the address increment memory M2 is repeated 32 times. When the scan address is transferred 16 × 32 times, the process returns to the beginning. Before the scan address is transferred, the values of the scan address memory M1, the number counter memory M3, and the block number counter memory M4 are all set to 1.

Now, as shown in FIG. 4, the scanning electrodes 1, 3, 5,
.., The 511st image is black, and the 2,4,6,.
Then, a black signal and a white signal are repeated for each information signal. In this case, the repetition frequency is 1 / (1 × 2 × 96 μ
sec) = 5208 Hz (> 40 Hz), and no flicker occurs.

On the other hand, in the conventional two-interlace scanning method, when the same image is displayed, 1, 3,
, 511 are sequentially selected to finish the first vertical scan, and subsequently, 2, 4, 6,..., 512 are sequentially selected and the second vertical scan is completed. Finish writing the screen. In this case, in the pixel P22, the black signal continues 256 times and the white signal continues 256 times, and the repetition frequency of the signal is 1 / (256
(× 2 × 96 μsec) = 20.3 Hz (<40 Hz), and flicker occurs.

When the 8-interlaced scanning method is used to avoid flicker, the frequency becomes higher and flicker disappears. However, since the screen is constituted by scanning every eight lines, the visibility of the moving image is significantly higher than that of the interlaced scanning. descend.

(Embodiment 2) The field frequency is set to 40 Hz.
In order not to be less, select a block randomly,
A method of writing the entire screen may be used. For example, in the device described in the first embodiment, the block selection order is B1, B1
0, B3, B8, B13, B2, B15, B12, B
5, B14, B7, B16, B9, B6, B11, B4
By doing so, the same effect as in the first embodiment can be obtained.

At this time, as shown in FIG. 9, the address table memories MT (1) to MT (16) sequentially store 1,28
9,65,225,385,33,449,353,1
29,417,193,481,257,161,32
16 addresses of 1,97 are set in advance.

(Embodiment 3) Next, 1024 scanning electrodes,
An example of a liquid crystal display device using 1280 matrix electrodes will be described and compared with a conventional example. When the selection time per one scanning electrode is 96 μsec, the frame frequency is 1 / (1024 × 96 μsec) = 10.2H
z. Therefore, to make the field frequency 40 Hz or more, the entire screen is constituted by four vertical scans. Then, as shown in FIG.
, And B1, B5, B9, B13, B17, B21, B25,
Select the block of B29, and in the second field,
B7, B11, B15, B19, B23, B27, B3
1 block is selected, and B2, B
6, B10, B14, B18, B22, B26, B30
, And in the fourth field, B4, B8,
Blocks B12, B16, B20, B24, B28, and B32 are selected. Then, non-interlace scanning is performed in each block.

As a whole, 1, 2, 3,...
31, 32, 129, 130, ..., 160, 257,
258, ..., 288, ..., 897,898, ...,
The 928th scanning electrode is selected to complete the first vertical scanning, and subsequently, 65, 66, 67,..., 95, 96, 19
3,194, ..., 224,321,322, ..., 3
, 961, 962,..., 992th scan electrode are selected to complete the second vertical scan.
3, 34, 35, ..., 63, 64, 161, 162
..., 192, 289, 290, ..., 320, ...
.., 929, 930,..., The 960th scanning electrode is selected, and the third vertical scanning is completed.
9, ..., 127,128,225,226, ..., 2
56, 353, 354, ..., 384, ..., 99
, 994,..., The 1024th scanning electrode is selected, the fourth vertical scanning is completed, and the entire screen is written.

To implement this method, a memory 800 is provided in the scanning signal control circuit 104 as shown in FIG. The fixed value is 1 in the address increment memory M2, and 1,129, in the address table memories MT (1) to MT (32).
257, 385, 513, 641, 769, 897, 6
5,193,321,449,577,705,83
3,961,33,161,289,417,545,
673,801,929,97,225,353,48
The scanning addresses to be selected first in each block when viewed from the entire 32 of 1,609,737,865,993 are the first vertical scanning, the second vertical scanning, the third vertical scanning, and the third vertical scanning. It is set in the order of four vertical scans.

The scan address is set in step 2 in FIG.
In M4, the condition for judging the end of all block writing
Except for changing to> 32, it is determined by the same algorithm as the algorithm in FIG.

Now, as shown in FIG. 4, the scanning electrodes 1, 3, 5,
..., The 1023th line is black, 2, 4, 6,.
When the image is an image in which black, white, black and white alternate, the pixel P
At 22, the black signal and the white signal are repeated as information signals one by one. The repetition frequency is 1 / (1 × 2 × 96 μsec)
= 5208 Hz (> 40 Hz), and no flicker occurs.

On the other hand, when the same image display is performed by the conventional 4-interless scanning method, 1, 5, 9,...
The first vertical scanning is sequentially selected to complete the first vertical scanning.
.., 1023, are sequentially selected, and the third vertical scan is completed.
,..., The 1024th line is selected, the fourth vertical scan is completed, and the entire screen is written. In this case, in the pixel P22, the black signal and the white signal are switched every 256 times. here,
The repetition frequency is 1 / (256 × 2 × 96 μsec) =
20.3 Hz (<40 Hz), and flicker occurs.

In order to avoid flicker, if a 16-interlaced scanning method is used, the repetition frequency is increased and flicker is eliminated. However, since a screen is formed by scanning every 16 lines, the visibility of a moving image is lower than that of non-interlaced scanning. Significantly lower.

(Embodiment 4) The field frequency is 40 Hz.
In order to avoid the following, a method in which blocks are randomly selected and the entire screen is written may be used. For example, in the scanning of the third embodiment, the selection order of the blocks is B1, B18, B27, B
12, B5, B22, B31, B8, B17, B2, B
23, B20, B29, B14, B11, B32, B1
3, B26, B3, B16, B9, B30, B19, B
4, B25, B10, B7, B28, B21, B6, B
15, B24 can provide the same effect as in the third embodiment. At this time, as shown in FIG. 12, the address table memories MT (1) to MT (32) sequentially store 1,5
45,833,353,129,673,961,22
5,513,33,705,609,897,417,
321,993,385,801,65,481,25
7,929,577,97,769,289,193,
32 addresses 865, 641, 161, 449, and 737 are set in advance.

Table 1 summarizes the results of display using the display devices of the first and second embodiments described above.

[0065]

[Table 1]

Similarly, Table 2 summarizes the display results of the display devices of Embodiments 3 and 4 described above.

[0067]

[Table 2]

FIG. 13 is an example of the driving waveform used in each of the above embodiments, and FIG. 14 is a communication timing chart of the apparatus shown in FIG.

In each of the above embodiments, the number of the scanning electrodes in one block is 32.
This is because the height of the pattern of the icon, the mouse, and the like was 32 dots or less, and flicker did not occur due to the scanning drive in 32 lines. If the number of scanning electrodes in a block is increased, the probability that a block will be bordered in the middle of displaying a font or the like is reduced, and good visibility is obtained, but on the contrary, flicker due to scanning drive is likely to occur. Conversely, when the number of scanning electrodes in a block is reduced, the probability that a block boundary comes in the middle of displaying a font or the like increases. In particular, when the number of scanning electrodes is equal to or smaller than the number of dots in the height direction of a font or the like, there is always a block boundary in the middle of font display, and the scanning jumps over there. For the above reasons, 1
The number of scanning electrodes in the block is a number that does not cause flicker due to scanning driving, and satisfies the number of dots in the height direction of the pattern of the display system, such as fonts, icons, mice, etc. Is a preferable condition. And, the larger the number satisfying the above, the better visibility is obtained.

[0070]

As described above, according to the present invention, the scan electrode group is divided into four or more blocks in which each block has a plurality of continuous scan electrodes, and one scan is performed during one vertical scan in one frame. Since the blocks are sequentially selected with an interval of at least one block or more and a scanning selection signal for sequentially scanning a plurality of adjacent scanning lines is applied within the selected block, an information signal for displaying a repetitive image is provided. In this case, it is possible to suppress a decrease in the frequency at which the black signal and the white signal are exchanged, to avoid flicker, and to improve the image quality of the display device while maintaining the visibility of the moving image.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram for explaining a basic configuration of a display device according to an embodiment of the present invention.

FIG. 2 is a timing chart showing an example of a scanning signal used in the display device of FIG.

FIG. 3 is a block diagram illustrating a configuration of a liquid crystal display device according to a first example of the present invention.

4 is an enlarged view of a liquid crystal display unit of the device shown in FIG.

FIG. 5 is a sectional view of FIG.

FIG. 6 is a schematic diagram for explaining the operation of the display device according to the first embodiment of the present invention.

7 is a conceptual diagram of a memory in a scanning signal control circuit of the device of FIG.

FIG. 8 is a flowchart showing an algorithm when driving the device of FIG. 3;

FIG. 9 is a conceptual diagram of a memory according to a second embodiment of the present invention.

FIG. 10 is a schematic diagram for explaining the operation of the display device according to the third embodiment of the present invention.

FIG. 11 is a conceptual diagram of a memory according to a third embodiment of the present invention.

FIG. 12 is a conceptual diagram of a memory according to a fourth embodiment of the present invention.

FIG. 13 is a waveform diagram of a drive signal.

FIG. 14 is a communication timing chart.

[Explanation of symbols]

BK1 to BK4: block, C11 to C44: scan line,
DPU: display unit, S1 to Sm: information signal line, CELi,
j ...: pixel, 101: liquid crystal display unit, 102: scanning signal application circuit, 103: information signal application circuit, 104: scanning signal control circuit, 105: drive control circuit, 106: information signal control circuit, 107: graphic Controller, C1
C6: scanning electrode, S1 to S6: information electrode, P22: pixel, 301: analyzer, 302, 304: glass substrate, 303: ferroelectric liquid crystal, 305 polarizer, 30
6: spacer, B1 to B32: block, M1: scan address memory, M2: address increment memory, M3: number counter memory, M4: block number counter memory, M
T (1) to MT (16): address table memory, 5
00,800: Memory.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-62-253126 (JP, A) JP-A-1-289918 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02F 1/133 G09G 3/20 G09G 3/36

Claims (10)

(57) [Claims] 1. A matrix having a scanning line group and an information signal line group intersecting with the scanning line group, pixels provided at intersections of the matrix, and driving for displaying the pixels in the matrix in the matrix. Means for supplying a signal, wherein the scanning line group is composed of at least four or more blocks composed of a plurality of adjacent scanning lines, and the means comprises one vertical scan in one frame 2 adjacent inside
Display means for sequentially selecting the four or more blocks so as not to select one block continuously, and sequentially scanning a plurality of adjacent scanning lines in the selected block. apparatus. 2. The display device according to claim 1, wherein the pixels are constituted by liquid crystal cells. 3. The display device according to claim 1, wherein the pixels are formed of a liquid crystal cell containing a ferroelectric liquid crystal. 4. The display device according to claim 1, wherein the pixels are constituted by a liquid crystal cell having a switch element. 5. The display device according to claim 1, wherein each of the blocks has the same number of scanning lines. 6. The display device according to claim 1, wherein the blocks are selected irregularly. 7. The display device according to claim 1, wherein the display device further comprises illumination means for illuminating the pixels. 8. The display device according to claim 1, wherein the display device further includes a graphic controller for controlling a display image. 9. The display device according to claim 1, wherein the display device further comprises a recording unit for recording a display image. 10. A matrix having a scanning line group and an information signal line group intersecting with the scanning line group, pixels provided at intersections of the matrix, and driving for displaying the pixels in the matrix in the matrix. And a means for supplying a signal. A display method for performing display using a display device, comprising: a scanning line group including at least four blocks including a plurality of adjacent scanning lines; One drop in
Display is performed by sequentially selecting the four or more blocks so that two adjacent blocks are not continuously selected during the direct scanning, and sequentially scanning a plurality of adjacent scanning lines in the selected block. A display method characterized in that: