JP2774502B2 - Display device, drive control device thereof, and display method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention]   The present invention relates to a display device and a driving method control device thereof.
Things. [Conventional technology]   CRTs that form images using the afterglow characteristics of phosphors
(Sword ray tube) and driving voltage effective value
TN (Twisted) that forms an image using the over-light amount characteristic
・ On a nematic) type LCD (liquid crystal element), 1
Keep the frame frequency, which is the screen formation frequency, above a certain value.
Need to be one. It is generally 30 Hz or higher,
This frame frequency is determined by the number of scanning lines that make up the display
Can be expressed as the reciprocal of the product of the horizontal scanning time and
Can be. At present, the scanning method is interlaced.
And a non-interlace system.   Other methods include pairing and LCD.
It is limited, but it is recommended to use
The plan has been put to practical use. In the NTSC standard, frames
Interlace of 2 fields / frame with 30Hz frequency
Method, the horizontal scanning time is about 63.5μsec, the number of scanning lines
Is about 480 lines (effective number of display lines). TN type LCD
With 200 to 400 scanning lines and a frame frequency of 30 Hz or less
The above is a non-interlaced system. Also on the CRT
Is a non-frame frequency of about 40 to 60 Hz separately from the NTSC standard.
An interlaced system is also used, and the number of scanning lines is 200
It is about 1000.   Here, suppose that the CRT and T of 1920 (vertical (scanning line) × 2560 horizontal pixels)
Consider driving an N-type LCD. Frame frequency
Several 30Hz, interlaced, horizontal scanning
The time becomes about 17.5 μsec, and the horizontal dot clock frequency
Is approximately 147MHz (not taking into account the horizontal retrace time on the CRT)
No). Horizontal dot clock frequency 1 for CRT
47MHz has a very high beam scanning speed and is suitable for current picture tubes.
Greatly exceeds the maximum electron beam modulation frequency of the electron gun in
To be able to produce accurate images even when scanning at 17.5 μsec.
Can not. In the case of TN type LCD, driving of 1920 scanning lines is
Duty ratio of 1920 and the current maximum duty ratio of 400
It cannot be displayed much beyond the degree. So, horizontal scanning
Considering driving with a realistic time value,
Mostly the frame frequency is lower than 30Hz,
The scanning state is visually recognized, flickers, and
Significantly impairs the display quality. Thus, large screens of CRT and TN type LCD
Surface area and high density are due to the display principle and restrictions of driving elements etc.
The number of scanning lines could not be increased enough.
That is the current situation.   By the way, in recent years, Clark and Lager Well responded fast.
US Patent No. 4,36
Published in 7,924 publications.   This ferroelectric liquid crystal device is generally used in a specific temperature range.
And chiral smectic C phase (SmC^*) Or H phase (SmH
^*) And in this state respond to the applied electric field
The first optically stable state and the second optically stable state
Take the shift and when no electric field is applied, change the state
Maintains properties, that is, has bistability and changes in electric field
Response is fast, fast and memorable
It is expected to be widely used as an indicator.   However, in general, ferroelectric liquid crystal devices are
It is difficult to have bistability as proposed by
It has a strong tendency to have a monostable state. Clark et al.
Shearing due to sharing to achieve bistability
Utilizing the orientation control method by applying force or applying magnetic field
However, from the viewpoint of production technology, as an orientation control method,
Based on uniaxial orientation treatment such as rubbing or oblique deposition
The method of applying to the plate is advantageous. Such uniaxial orientation processing
The ferroelectric liquid crystal element whose orientation is controlled by giving
In some cases, permanent bistability did not occur. This permanent
An alignment state that does not cause excessive bistability. So-called monostable orientation
The state is within a range of several milliseconds to several hours.
It has the property that the direction changes to uniaxial orientation when there is no electric field.
Therefore, a table using this monostable ferroelectric liquid crystal device was
In the display device, the image that has been written once is
There was a problem that disappeared. In particular, multiple
At the time of driving, the scanning line
In some cases, the written state of the pixel gradually disappeared.   Therefore, for such a problem, the selected scanning line
Voltage signal causing "black" and "white"
Voltage signals to be selectively applied to sequentially select scanning lines.
When the cycle is one frame or one field, this cycle
Drive method (write refresh)
Drive) is considered. Such refresh drive
By adopting this method, the amount of transmitted light
Fluctuations are very small and the frame frequency is less than 30Hz
Even at low frame frequencies, viewing of the write scan line
(The scanning writing line has higher brightness than other lines.
And it can be easily determined visually)
The occurrence could be eliminated.   At this time, according to the study by the present inventors, a frame of about 5 Hz
At the same frequency
I was able to.   The above fact is due to the limitations of CRT and TN type LCD mentioned above.
Must be driven at a frame frequency above 30Hz
Larger screens and higher definition that have arisen from the essential condition of
It is effective for overcoming the problems at once. [Technical problem to be solved by the invention]   However, as mentioned above, the re-
In the case of fresh drive, character editing and graphics
Such as smooth scrolling and cursor movement on
Display speed is slow and display performance
May fall. For example, using a ferroelectric liquid crystal element
For display devices, conventional display devices (CRT, TN type LCD, etc.)
A display device that enables a much larger screen and higher definition
However, with the increase in screen size and definition,
System frequency becomes low frequency, so
The speed of rules and cursor movement was sometimes reduced.   In recent years, computers and their peripheral circuits and software
Remarkable development, especially for large screens and high-definition displays
In contrast, multiple windows are called
A display method of displaying a number of screens in a superimposed manner has become widespread.   Therefore, a display device suitable for such a multi-window
Is desired. [Means to solve the problem]   Therefore, an object of the present invention is to solve the above-mentioned problem and to provide
Display using a ferroelectric liquid crystal element that is easy to show monostability
Even with devices, stable still images are displayed while low frame
Cursor movement and zooming even under the
Moving image display such as smooth scroll or multi-window, or
Display device substantially speeding up video moving image display and its display device
It is to provide a drive control device and a display method.   That is, a plurality of scan electrodes and a plurality of
Number of information electrodes and chiral smectic liquid crystal
A display panel having a display screen;
A first means for applying a selection signal and information on the information electrode;
A driving means having a second means for applying a signal;
In a display device comprising:
Number of scan electrodes are sequentially selected for scanning and the plurality of information
A refresher that repeats the operation of applying information signals to the electrodes
1st routine for flash drive and
Corresponding to the changed display information of the display screen.
Scanning only a part of the scanning electrodes and displaying the part
And a second routine for rewriting
The period for executing the first routine and the second routine
And the period for executing the routine alternates in chronological order.
Thus, the second routine is continuously executed for a predetermined period or more.
Control means for controlling the driving means so as not to
Display device.   In addition, a plurality of scan electrodes and a plurality of
Display with information electrode and chiral smectic liquid crystal
A display panel having a screen, and a scan selection signal applied to the scan electrode.
Scanning electrode drive circuit for applying the
Information electrode drive circuit for applying a signal and a display device provided
In the drive control device for installation, the multiple
Number of scan electrodes are sequentially selected for scanning and the plurality of information
A refresher that repeats the operation of applying information signals to the electrodes
1st routine for flash drive and
Corresponding to the changed display information of the display screen.
Scanning only a part of the scanning electrodes and displaying the part
And a second routine for rewriting
The period for executing the first routine and the second routine
And the period for executing the routine alternates in chronological order.
Thus, the second routine is continuously executed for a predetermined period or more.
Drive having control means for controlling the drive means so that
Dynamic control device.   Further, the present invention provides a method for scanning a plurality of scan electrodes and intersecting the scan electrodes.
Multiple information electrodes and chiral smectic liquid crystal
A display panel having a display screen provided with
A first means for applying a test selection signal and information to the information electrode.
Driving means having a second means for applying a notification signal
And a display method using a display device comprising:
Sequentially selecting the plurality of scan electrodes according to the display information
And an operation of applying an information signal to the plurality of information electrodes.
A first routine for repetitive refresh drive;
According to the change of the display information, the display screen has been changed.
Scan only a part of the scan electrodes corresponding to the display information
A second routine for rewriting the display image of the part;
Is executed continuously for a predetermined period or more.
Display method that is executed alternately in chronological order
You. [Action]   According to the present invention, even if the display screen is partially rewritten,
Rewriting can be performed at high speed while maintaining the display quality of the background. (Detailed description of embodiments of the invention)   FIG. 1 shows a liquid crystal display device according to the present invention and drive control.
FIG. 3 is a configuration diagram of a main unit. FIG. 2 shows the display information signal.
4 shows a timing chart. The display panel 11 is a scanning electrode 12
Matrix structure of C (1920 lines) x information electrode 13D (2560 lines)
Then, ferroelectric liquid crystal is sealed in this, and scanning is performed on the scanning electrode 12C.
Connect electrode drive circuit 12 and drive information electrode to information electrode 13D
The circuit 13 is connected. The scan electrode drive circuit 12 has a decoder 12
A and an output stage 12B are provided.
Shift register 13A, line memory 12B and output stage 13C
Have been.   First, the scan electrode address data specifying the scan electrode 12C is set.
Data and video data on four signal lines PD0, PD1, PD2 and PD3.
Then, the data is output from the main unit 14 to the control circuit 15. This embodiment
Now, scan electrode address data (A0, A1, A2, A3, A4,
A5, A6, A7, A8, A9, A10, A11) and video data (D0, D
1, D2, D3, ... D2558, D2559) are those of the signal lines PD0 to PD3
Since the data is transferred on each of the same transmission lines, the scan electrode address
Data and video data. This example
Then, A / is provided as a signal for identification,
When this A / signal is high level, the scan electrode address data
Data at the low level and video data at the low level.
Are defined to show that
You. In addition, A / signal is used to transfer display
It also includes the meaning as the first signal.   Apply scan electrode address data to scan electrode drive circuit 12
When applying image data to the information electrode drive circuit 13,
The electrode address data A0 to A11 and the video data D0 to D2559
Scanning is performed serially on signal lines PD0-PD3.
Electrode address data A0 to A11 and video data D0 to D2559
Dividing circuit or scan electrode address data A0 to A11
A circuit for extracting the data is required.
Perform at The control circuit 15 controls the signal lines PD0 to PD3.
Extract scan electrode address data A0 to A11 to be placed,
When temporarily storing and driving the designated scanning electrode 12C,
Output to the scan electrode drive circuit 12 during the horizontal scanning period. this
The operation electrode address data A0 to A11 are stored in the scan electrode drive circuit 12.
Is input to the decoder 12A inside and scanned through the decoder 12A
Select the electrode 12C.   On the other hand, the video data D0 to D2559 are stored in the information electrode drive circuit 13.
And the transfer clock CLK
Shift every 4 pixels to correspond to information electrodes 13D (2560 lines)
The video data D0 to D2559 having a certain number of pixels are separated. shift
Shift of one scanning line in the horizontal direction is completed by register 13A
Then, the video on the shift register 13A of these 2560 circuits
Data D0 to D2559 are transferred to line memory 13B and
Stored within the scanning period.   In this embodiment, the driving of the display panel 11 and the
Scan electrode address data A0 to A11 and video data
Since the generation of data D0 to D2559 is performed asynchronously, it is displayed
Synchronization between the control circuit 15 and the main unit 14 during information transfer
Need to be taken. This synchronization signal is horizontal with the signal Sync.
Generated by the control circuit 15 for each scan.   This signal Sync indicates the action associated with A /
I do. The main unit 14 constantly monitors the Sync signal.
If the signal is low level, display information is transferred, and conversely
If high level, transfer of display information for one horizontal scan is completed.
After the transfer, no transfer is performed. That is, in FIG.
The moment the signal goes low, the A / signal goes high.
And the control circuit 15 outputs the Sync signal during the display information transfer period.
Return to high level during. And measure from point A
After one horizontal scanning time has passed (point B), the level changes to low level.
return. If the main unit 14 continuously displays information at the point B,
When transferring information, that is, when driving the next scan electrode
Sets the A / signal to high level again and starts transfer. Book
In this embodiment, the refresh drive is used, so that the line
Move.   The defined one horizontal scanning time is defined as ferroelectric
Is determined based on the characteristics of the crystalline liquid crystal and the driving method.
A desired application time is determined in consideration of various optimum driving conditions,
This is defined as one horizontal scanning time. In this embodiment,
In general, one horizontal scanning time (period) is about 80μ at room temperature.
Set to sec. Therefore, the frame frequency is about 6.5
Hz. The transfer clock CLK is set to 12 MHz and scanning is performed.
Transfer time of electrode address data and video data is about 54μse
becomes c. The waiting time in FIG. 2 is about 26 μsec.
You. The control signal CNT in FIG. 2 generates a desired drive waveform.
This is a control signal to be generated. This is from the control circuit 15
The signals are output to the respective drive circuits 12 and 13. CNT output timing
Scan electrode drive scan electrode address data A0 to A11
It is the same as the timing to output to the circuit 12, and the shift register
To transfer the video data of the master 13A to the line memory 13B.
Same as imming.   The timing of these CNT signals waits as shown in FIG.
The time between the start of the time and the start of the low level of the Sync signal
Beginning at any time within period C, valid for one horizontal scanning period
Is output as an appropriate drive control signal. In this embodiment, the reflation
Because it is a flash drive, a certain time during period C
It is the beginning (access start), and at the same time
It is also the driving end point.   The above communication is performed with the drive circuits 12, 13 and the control circuit 15.
Drive timing between the main unit 14 and
Refresh driving is performed with a clock.   Next, a display information generating means which is a characteristic configuration of the present invention.
Will be described.   The generation of the display information is performed by the main unit 14 and described in the above A.
Occurs according to the specifications based on solid signal transfer. Here
This is called an image forming circuit.   FIG. 3 shows a main program for generating display information in the partial write routine.
It is a program. This operation is shown in FIG. New from CPU
Judge whether rewriting data is coming,
Repeat the above, and if it comes, write the previous history data of VRAM
Rewrite and write new data (VRAM stores video data
Memory to store). Thus, the image forming circuit
Is the scanning electrode address for the video data newly sent from the CPU.
The address data is added and transferred to the control circuit 15.   On the other hand, full refresh driving is constant as described above.
To be executed at intervals. Because of this,
Full refresh using interrupt request to program
Drive is performed, and this interrupt is required at regular intervals.
In response to the request, the image forming circuit executes the routine shown in FIG.
I do. The operation shown in FIG.
Interrupt and reject new data from CPU. And
The display information of the entire screen is transferred to the control circuit 15. And next
Set the time until the full refresh drive of the
1 second in the example). And new data from CPU
Try to accept.   The operation of the present invention is determined by determining the operation of the image forming circuit as described above.
Perform the action method.   Next, the scan electrode address data is used to scan the display panel 11.
Scan electrode unique because it is an address corresponding to the scanning electrode 12C
Address data. Therefore, in this embodiment, the image forming
The data in VRAM managed by the circuit is mapped as shown in Fig. 5.
I did. First, it is divided into two areas, one of which is a scanning electrode
One was assigned to video data. Scanning power
The pole address data area corresponds to the pixel of the display panel 11,
One line of the corresponding video data is arranged,
The scan electrode address data was placed at the head of the data. Said
Details of data mapping in VRAM are shown in FIG.
become. The first 16 bits of serial data are the scan electrode address.
The following 2560 bits are video data.   The display information sent to the control circuit 15 is the data shown in FIG.
Display information for one scanning line is sent in a format.   Next, the drive signal applied to the display panel 11 will be described.
You.   7 and 8 show driving waveforms used in this embodiment.
You. FIG. 7 shows the odd frame F_2M-1And even frame F
_2M(M = 1, 2, 3,...)
Scan selection signal S to be applied_2n-1(N = 1, 2, 3, ...) and even
Scan selection signal S applied to the number-th scan electrode_2nIs shown
ing. According to FIG. 7, the scanning selection signal S_2n-1Is odd
Room F_2M-1And even frame F_2M(M = 1, 2, 3, ...)
Voltage polarity in phase (based on the voltage of the scan non-selection signal)
Voltage polarity) are opposite to each other,
Signal S_2nThe same is true for In addition, mark within one frame period
Scan selection signal S added_2N-1And S_2nAre different
Voltage waveform, and the voltage polarity of the same phase is opposite to each other
It has become.   In addition, in the scanning drive waveform example of FIG.
Stop (for example, apply voltage 0 to all pixels composing the screen at once)
The third phase is provided for scanning
The third phase of the signal is voltage 0 (the voltage of the scanning non-selection signal
(At the same level).   According to FIG. 7, the odd frame F_2M-1With signal electrode
The information signal to be applied to the scan selection signal S_2n-1To
The white signal (scanning selection signal S_2n-1And 2
3V above the threshold voltage of ferroelectric liquid crystal in the 3rd phase₀
Is applied to form a white pixel) and a holding signal (scan selection).
Select signal S_2n-1And the threshold of the ferroelectric liquid crystal
Voltage less than value voltage ± V₀Is applied) and selectively
Applied, scan selection signal S_2nTo the black signal (scan selection)
Select signal S_2nAnd ferroelectric liquid in the second phase
-3V beyond the crystal threshold voltage₀Is applied to black pixels
) And a holding signal (scan selection signal S_2nFor synthesis with
The voltage is smaller than the ferroelectric liquid crystal by ± V₀Is applied
Are selectively applied.   Odd frame F mentioned above_2M-1Followed by an even frame
Room F_2MThe information signal applied to the signal electrode
Inspection selection signal S_2n-1To the same black signal as described above.
And a scan selection signal S_2nAgainst
The same white signal and hold signal as above
Is done.   FIG. 8 is shown in FIG. 9 by the driving waveforms shown in FIG.
Show the timing chart when the display state is written
I have. In FIG. 9, ○ represents white pixels and ● represents black pixels.
ing. Also, I in FIG.₁−S₁Scan electrode S₁And signal electrode I₁
5 is a time-series waveform of a voltage applied to an intersection with the above. I_Two−S₁
Is the scanning electrode S₁And signal electrode I_TwoOf the voltage applied at the intersection with
It is a time-series waveform.   In addition, the present invention, in addition to the driving method described above, U.S. Pat.
Publication No. 655,561 German publication No. 3501982, German publication
No. 3,644,220, etc.
Can also be. (Example)   FIG. 10 is a timing chart showing the display operation principle of the present invention.
It is. The first frame is a full refresh driving period.
You. At this time, if rewriting information is generated,
14 is the rewriting display information (scanning electrode
(Address data + video data) are prepared. And 2
From the beginning of the frame,
Enter the partial write operation with the signal transfer means
The transfer means includes a full refresh drive state and partial write
The same regardless of state). When partial writing is completed, 1
As soon as a certain time starts from the frame, the entire surface is refreshed again.
Drive.   Here, when the rewrite information does not reach the front,
In case of partial writing scan electrode <total scan electrode number (1920)
In this case, after the partial writing is completed as shown in FIG.
As soon as it becomes, the whole surface is refresh-driven.   Next, when the rewriting information reaches the front, that is, partial writing
If the number of scan electrodes included in the scan is greater than or equal to the number of scan electrodes (1920),
As shown in FIG. 10 (B), the entire surface is refreshed in the first frame.
Frame frequency for full refresh drive after flash drive
And the entire writing is continued until the end.   In this embodiment, the entire refresh driving cycle is set to 1 second.
Was.   FIG. 11 shows an embodiment of a multi-window screen display.
You. The display screen displays different screens in the display area.
It is a thing. Window 1 is a pie chart of certain tally results
Screen expressed in. Window 2 is the sum of window 1
A screen that expresses the results in a table. Window 3 is window 1
A screen that displays the results of the aggregation in a bar graph. Window 4 is a sentence
Performs operations related to chapter creation. And the background is white nothing
Earth.   Here, window 4 is the work screen, and other windows
The window is in a still image state. So window 4 is a sentence
A movie is being displayed while a chapter is being created. The specifics of this video state
Operations include scrolling, inserting and deleting words and phrases, and copying.
-, Area movement, etc. These actions are relatively fast
I need a crop. Hereinafter, a display operation example will be described.   First example-One character is added to an arbitrary line in window 4
Additional display. The character font has a 16 × 16 configuration.
Displaying one additional character rewrites 16 scanning electrodes
It is to get. Write only 16 scan electrodes during refresh drive
The replacement timing is 16 partial write scan electrodes.
<Because the total number of scanning electrodes (1920) is shown in FIG.
The timing is as follows. The first frame is fully refreshed
16 scan electrodes from the beginning of the second frame
Drive time of 16 × 80 = 1.28 msec, partial writing
One second after driving the frame, refresh the entire surface again
Drive. After the partial writing is completed, about (1000msec-153.6m
sec-1.28 msec).   Second example-window 4 is in a smooth scroll state.   Assume that the number of scanning electrodes occupied by window 4 is 400.
You. The smooth scroll display can be rewritten by 400 lines.
You. Driving 400 scan electrodes during refresh drive
The timing is the same as in the first example. One frame
The eyes are fully refreshed and the beginning of two frames
From 400 scan electrode drive time 400 x 80 μsec = 32 msec
Section until the full refresh drive start time
Minute writing continues. At this time, smooth scroll
Speed is about (1000msec-153.6msec) / 32msec = 261ine
Per second. General smooth scroll speed is 10 ~ 301in
From e / sec, the smooth scroll speed shown in the second example is
Not late.   FIG. 12 shows a ferroelectric liquid crystal cell as a display means of the present invention.
This is a schematic drawing of an example of a file. Transparent electrode coated
Between the upper and lower electrode substrates (glass substrates) 121A and 121B
A layer 122 composed of ferroelectric liquid crystal molecules is formed on an electrode substrate 121.
A, 121B is sealed vertically. This invites
The conductive liquid crystal exhibits a chiral smectic C or H phase.
Loses the inherent helical structure of the chiral smectic phase
Thickness thin enough to cause (eg, 0.5 μm to 5 μm)
Is set to   Above a certain threshold between upper and lower electrode substrates 121A and 121B
When an electric field E (-E) is applied, the liquid crystal molecules 123 move in the direction of the electric field.
Change the orientation direction. Liquid crystal molecules have an elongated shape.
In addition, it exhibits refractive index anisotropy in the major axis direction and the minor axis direction. So
Here, a crossed Nicol polarizer is placed above and below the glass surface (Figure
(Not shown), depending on the polarity of the applied electric field E (−E),
It becomes a liquid crystal modulation element whose chemical characteristics change. In such a cell
When an electric field E exceeding a certain threshold is applied, the liquid crystal molecules 123
Is oriented to the first stable state 123A. Also, the opposite electric field
When E is applied, the liquid crystal molecules 123 enter the second stable state 123B.
Orientation can change the orientation of the molecule. In addition,
As long as the field does not exceed E and -E certain thresholds,
Each alignment state is maintained.   The ferroelectric liquid crystal element used in this example has a monostable alignment state.
The first stable state 123A and the second stable state
The stable state with 123B is asymmetric, and the electric field E or -E
After release, either stable state or another more stable
To a stable third stable state. In the present invention,
It is preferable to apply such a monostable alignment state to ferroelectric liquid crystal devices.
Suitable but disclosed in U.S. Pat.No. 4,367,924
Aligned state that exhibits semi-permanent or permanent bistability
Launched ferroelectric liquid crystal devices and European Patent No. 91661
Ferroelectricity of the oriented state with a helical structure as shown
Application to a liquid crystal element is also possible.   FIGS. 13 (A) and (B) show one embodiment of the liquid crystal element of the present invention.
An example is shown. FIG. 13 (A) shows a liquid crystal device of the present invention.
FIG. 13B is a sectional view taken along the line AA ′ of FIG.   The cell structure 130 shown in FIG.
A pair of substrates 131A and 131B made of a tick plate etc. are spacer
At 134, the substrates are held at predetermined intervals, and the pair of substrates is sealed.
Has a cell structure bonded with an adhesive 136 for
And a plurality of transparent electrodes 132A on the substrate 131A.
Electrode group (for example, scanning of a matrix electrode structure)
Voltage application electrode group) is a predetermined pattern such as a band-shaped pattern.
It is formed with The transparent electrode described above is placed on the substrate 131B.
An electrode group consisting of a plurality of transparent electrodes 132B crossing the poles 132A
(For example, for applying a signal voltage in the matrix electrode structure
Electrode group) is formed.   The substrate 131B provided with such a transparent electrode 132B has, for example,
For example, silicon monoxide, silicon dioxide, aluminum oxide, jill
Konia, magnesium fluoride, cerium oxide,
Lium, silicon nitride, silicon carbide, boron nitride
Materials, such as inorganic insulating materials, polyvinyl alcohol,
Imide, polyamide imide, polyester imide, poly
Laxilelin, polyester, polycarbonate, poly
Vinyl acetal, polyvinyl chloride, polyamide, poly
Styrene, cellulose resin, melamine resin, urea resin
Film using an organic insulating material such as
The alignment control film 135 can be provided.   This alignment control film 135 is made of an inorganic insulating material as described above or
After coating the organic insulating material, the surface
By rubbing one side with cloth, paper or cloth
can get.   In another preferred embodiment of the present invention, SiO or SiO_TwoSuch as
Inorganic insulating material coated on substrate 131B by oblique evaporation
By forming, the orientation control film 135 can be obtained.
Wear.   In another embodiment, it is made of glass or plastic.
The inorganic material described above on the surface of the substrate 131B or on the substrate 131B
After forming a film of insulating material or organic insulating material,
Etching the surface by oblique etching
Thus, an orientation control effect can be imparted to the surface.   The aforementioned orientation control film 135 also functions as an insulating film at the same time.
Preferably, the orientation control film 135 is used for this purpose.
Generally has a thickness of 100Å to 1 、, preferably 500Å to 5000Å.
Can be set in the range. This insulating film is the liquid crystal layer
Of current generated due to impurities etc. contained in traces in 133
It also has the advantage that it can be prevented from occurring, so
The liquid crystal compound is not deteriorated even when the operation is repeated.   Further, in the liquid crystal element of the present invention, the alignment control film 135 described above
A similar thing can be provided on the other substrate 131A.
You.   US Patent No. 4,561,726 discloses a ferroelectric liquid crystal 133.
No. 4,614,609, U.S. Pat.No.4,589,996
Publication, U.S. Pat.No. 4,592,858, U.S. Pat.
No. 6,667, U.S. Pat.No. 4,613,209
Liquid crystal compound or group exhibiting an isolated chiral smectic phase
A product can be used.   Also, in the figure, 133 and 138 are polarizing plates, and their polarization axes are
They cross each other, preferably at 90 °. This implementation
According to the example, a ferroelectric liquid crystal material having a strong monostable tendency is used.
While still displaying a still image, the part at low frame frequency
It can speed up the display of separate moving images. 〔The invention's effect〕   As described above, drive control of the display unit is performed.
More partial write (rewrite) drive and full refresh
It is possible to achieve both the balance driving and the driving.   Further, one horizontal scanning drive time is not related to the number of scanning electrodes.
Drive voltage and optical response characteristics for image formation.
In principle, it does not reach the aero-optical characteristics.
An image can be formed without limitation on the number of inspection electrodes.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a display device of the present invention, FIG. 2 is a chart diagram showing signal transfer and drive timing used in the display device of the present invention, and FIG. FIG. 4 is a sequence diagram showing a full-surface refresh driving routine. FIG. 5 is an explanatory diagram showing data mapping of VRAM. FIG. 6 is an explanatory diagram showing a data format of display data of one scanning line. FIG. 7 is a waveform diagram of a driving waveform used in the present invention, FIG. 8 is a timing chart showing the timing chart, FIG. 9 is an explanatory diagram showing a display state of a pixel, and FIG. FIG. 10 (B) is a timing chart when the number of electrodes <the number of full scan electrodes, FIG. 11 (B) is a timing chart when the number of partial write scan electrodes ≧ the number of full scan electrodes, and FIG. 11 is an example of an image display used in the present invention. Indicated FIG. 12 is a perspective view for schematically explaining a ferroelectric liquid crystal element used in the present invention, FIG. 13 (A) is a plan view of the element used in the present invention, FIG. B) is a sectional view taken along the line AA '.

   ────────────────────────────────────────────────── ─── Continuation of front page       (56) References JP-A-61-18929 (JP, A)                 JP-A-55-45085 (JP, A)                 JP-A-60-251787 (JP, A)                 JP-A-61-138991 (JP, A)                 JP-A-58-107782 (JP, A)                 JP-A-61-67894 (JP, A)                 Tokiko 57-15393 (JP, B2)

Claims (1)

(57) [Claims] A display panel having a display screen comprising a plurality of scan electrodes, a plurality of information electrodes intersecting the scan electrodes, and a chiral smectic liquid crystal; a first means for applying a scan selection signal to the scan electrodes; A driving unit having a second unit for applying an information signal to the information electrode, wherein the plurality of scanning electrodes are sequentially scanned and selected according to display information, and the plurality of information electrodes are selected. A first routine for refresh driving that repeatedly performs an operation of applying an information signal to the scan screen, and in response to a change in display information, scan-selects only a part of the scan electrodes of the display screen corresponding to the changed display information. A second routine for rewriting the display image of the part is executed, and a period for executing the first routine and a period for executing the second routine are different. Series in occurring alternately, as the second routine is not executed continuously over a predetermined time period, the display device comprising a control means for controlling said drive means. 2. The display device according to claim 1, wherein the change of the display information is for moving a cursor or scrolling a window. 3. The display device according to claim 1, wherein the change of the display information is for displaying a moving image. 4. 2. The display device according to claim 1, wherein only a part of the scan electrodes is repeatedly selected for scanning in accordance with a change in the display information. 5. When a part of the display information stored in the memory is changed during the execution of the first routine, the second routine is executed after one frame scan based on the display information before the change is completed. The display device according to claim 1. 6. When a part of the display information stored in the memory is changed during the execution of the first routine, the process shifts to the second routine, and the number of the scanning electrodes selected for scanning in the second routine is reduced. 2. The display device according to claim 1, wherein when the value exceeds a predetermined value, the process shifts to the first routine. 7. The first means is a scanning electrode drive circuit including a decoder, and the second means is an information electrode drive circuit including a shift register and a line memory.
The display device according to item. 8. A display panel having a display screen including a plurality of scan electrodes, a plurality of information electrodes intersecting the scan electrodes, and a chiral smectic liquid crystal; a scan electrode drive circuit for applying a scan selection signal to the scan electrodes; An information electrode drive circuit for applying an information signal to the information electrode, and a drive control device for a display device, comprising: a plurality of scan electrodes sequentially scanned and selected according to display information; A first routine for refresh driving that repeatedly performs an operation of applying an information signal; and, in response to a change in display information, scan-selects only a part of the scan electrodes corresponding to the changed display information on the display screen. A second routine for rewriting the partial display image, and a period for executing the first routine and a period for executing the second routine. A drive control device having control means for controlling the drive means such that the intervals alternate in time series and the second routine is not continuously executed for a predetermined period or more. 9. 9. The drive control device according to claim 8, wherein the change of the display information is for moving a cursor or scrolling a window. 10. 9. The drive control device according to claim 8, wherein the change of the display information is for displaying a moving image. 11. 9. The drive control device according to claim 8, wherein only a part of the scan electrodes is repeatedly selected for scanning in accordance with the change of the display information. 12. When a change occurs in a part of the display information stored in the memory during execution of the first routine, after the one-frame scanning based on the display information before the change is completed, the second
9. The drive control device according to claim 8, wherein the routine is executed. 13. When a part of the display information stored in the memory is changed during the execution of the first routine, the process shifts to the second routine, and the number of the scanning electrodes selected for scanning in the second routine is reduced. 9. The drive control device according to claim 8, wherein when the value exceeds a predetermined value, the process shifts to the first routine. 14． A display panel having a display screen including a plurality of scan electrodes, a plurality of information electrodes intersecting the scan electrodes, and a chiral smectic liquid crystal; first means for applying a scan selection signal to the scan electrodes; And a driving unit having a second unit for applying an information signal to the electrodes, wherein the display unit comprises: a plurality of scanning electrodes sequentially scanned and selected according to display information; A first routine for refresh driving that repeatedly performs an operation of applying information signals to a plurality of information electrodes; and a scan electrode corresponding to the changed display information in a part of the display screen in response to a change in display information. And a second routine for scanning and selecting only a part of the display image and rewriting the display image of the part is alternately executed in a time-series manner so that the second routine is not executed continuously for a predetermined period or more. Display method.