JPH09230313A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To rewrite drive control information, etc., by an external display control device by providing a drive control means which displays images based on the image information supplied from an external device connected to the display device in accordance with the driving control information stored in a memory means. SOLUTION: A display device 50 supplies horizontal synchronization signals to a display control device, which supplies the scanning line address and image data to a drive controller 51. In this case, the controller 51 selects the period of the horizontal synchronization signals according to the temperature information fed from the temperature sensor 52 so as not to break the display to the display device 56 which changes the response speed depending on temperature. In this way, the image data supplied from a display control device is supplied to segment drivers 53, 54 alloted to even numbers to be supplied to the transparent electrode of a display 56 in the form of driving waveform generated from the preset drive timing and the voltage selection code.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is capable of displaying an image on the basis of information from an external device when the external device is connected, and is internally stored in an offline state when the external device is disconnected. The present invention relates to a display device using a ferroelectric liquid crystal capable of displaying an image based on information.

[0002]

2. Description of the Related Art Conventionally, a CRT (Cathode Ra) has been used as a display device of a personal computer (hereinafter abbreviated as PC) or a work station (hereinafter abbreviated as WS).
y Tube) was used. But in recent years T
N (Twisted nematic), STN (Su
2. Description of the Related Art A display device using liquid crystal having a per twisted nematic structure or the like has come to be used in a laptop PC or the like because of its advantages in weight reduction and thinning which are possible due to its structure.

Display devices used in PCs and WSs are
In order to improve visual understanding based on ergonomics, graphic functions such as window function have been expanded, and high resolution and large screen are required to realize them.

Under these circumstances, Clarc and L
JP-A-56-10721 by Mr. Agerwall
The display device having ferroelectricity proposed in Japanese Patent Publication No. 6 and U.S. Pat. No. 4,367,924 has a memory property of image information, and therefore, compared with a conventional display device.
The number of scanning lines can be increased and high-definition display is possible.

As a method of driving this ferroelectric liquid crystal, control having temperature compensation described in US Pat. No. 4,922,241 proposed by Inoue et al. Is known. However, in order to use this display device as a display device of a man-machine interface, a decrease in frame frequency becomes a problem, partly because the scanning time increases in proportion to the high-definition display.

As a proposal for this problem, there is a partial rewriting scan (Kamibe et al., US Pat. No. 4,655,561) which preferentially drives a scanning line with changed image information. A frame rate improving method called "multi-interlace scanning + partial rewriting scanning" is proposed in Japanese Patent Laid-Open No. 63-65494 of Katakura et al.

[0007]

Currently known driving means for the ferroelectric liquid crystal display device include those having the following features.

(A) Information on the waveform applied to the liquid crystal element at the temperature is stored in a non-rewritable, non-rewritable storage device when the power is cut off.

(B) The image information for the display element is stored in a rewritable one-line storage device which is volatile when the power is cut off.

(C) The image information for the display element is stored in a rewritable storage device which is volatile when the power is cut off.

Conventionally, a display using a ferroelectric liquid crystal has been made possible by combining the means having the characteristics (a), (b) and (c) described above.

However, in the conventional ferroelectric liquid crystal display device having the above-mentioned characteristics, it is not possible to rewrite the information of the temperature and the waveform applied to the liquid crystal element when performing online display with the display control device. It was possible.

Further, in the conventional display device, it is volatile for the image storage device of the display device to turn off the power when the display control device is off-line, that is, when the display device is displayed in the stand-alone state. This is impossible because the display device does not have a means for synchronizing with the image storage device independently.

Further, in order to perform display in a stand-alone state by using the above-described partial rewriting scan or multi-interlace scan together, it is necessary to newly provide a means for storing the scan order.

An object of the present invention is to provide a display device in which drive control information and image information can be rewritten by an external display control device, and further, an optimum still image or moving image can be displayed independently. .

[0016]

To achieve the above object, the first means of the present invention has a liquid crystal panel in which a ferroelectric liquid crystal is sandwiched between glass substrates on which transparent electrodes are arranged, and a driving means. In a display device equipped with a display for displaying an image by changing the voltage applied to the transparent electrode by changing the orientation of the molecules of the ferroelectric liquid crystal,
An image based on image information supplied from an external device connected to the display device or an image based on image information stored in an internal image information storage means is displayed according to the drive control information stored in the storage means. It is characterized by comprising drive control means for displaying on a container.

In order to achieve the above object, the second means of the present invention is the drive control information according to the first means, wherein the drive control information is the temperature of the liquid crystal panel and the voltage applied to the transparent electrode by the drive means. It is a correspondence relationship with a waveform, and the storage means is a non-volatile storage means with respect to interruption of power supply.

In order to achieve the above object, the third means of the present invention is characterized in that, in the first means, the image information storage means is a non-volatile storage means with respect to a power-off. And

In order to achieve the above object, a fourth means of the present invention is the first means, wherein the drive control information is a pixel configuration of the liquid crystal panel, and the storage means is provided for shutting off power. On the other hand, it is a non-volatile storage means.

To achieve the above object, the fifth means of the present invention is the first means, wherein the drive control information is a scanning order for each pixel in the liquid crystal panel, and the storage means is It is characterized in that it is a non-volatile storage means for power-off.

In order to achieve the above object, the sixth means of the present invention is the first means, wherein the image information storage means and the storage means are non-volatile and rewritable upon interruption of the power supply. It is a storage means.

To achieve the above object, a seventh means of the present invention is the image information storage means and the storage means in the first means, wherein the image information storage means and the storage means are a flash memory or E.
It is a PROM.

In order to achieve the above object, the eighth means of the present invention is the image information stored in the image information storage means in the first means, and the drive control information stored in the storage means. Is rewritable by an external device connected to the display device.

To achieve the above object, the ninth means of the present invention is to write the image information in the image information storage means and the external device when rewriting the image information by the external device in the eighth means. When the image based on the image information stored in the image information storage means is displayed on the display, the read operation of the image information storage means and the operation of the drive means of the display are synchronized. The drive control means is further provided with a synchronizing means for synchronizing.

To achieve the above object, the tenth means of the present invention is the eighth means, wherein the drive control means further comprises an initial value storage means for storing an initial value of the drive control information. It is characterized by doing.

According to the first means of the present invention, the drive control means, according to the drive control information stored in the storage means,
An image based on the image information supplied online from an external device or an image based on the image information stored in the internal image information storage means can be displayed on the display.

According to the second means of the present invention, the correspondence relationship between the temperature of the liquid crystal panel and the voltage applied to the transparent electrode can be stored in the non-volatile storage means with respect to the interruption of the power supply.

According to the third means of the present invention, the image information can be stored in the non-volatile storage means even when the power is cut off.

According to the fourth means of the present invention, the pixel configuration of the liquid crystal panel can be stored in the non-volatile storage means when the power is cut off.

According to the fifth means of the present invention, the scanning order for each pixel in the liquid crystal panel can be stored in the storage means which is non-volatile when the power is turned off.

According to the sixth means of the present invention, the information stored in the non-volatile storage means can be rewritten when the power is shut off.

According to the seventh means of the present invention, the present invention can be implemented by using a flash memory or EPROM.

According to the eighth means of the present invention, the image information stored in the internal image information storage means and the drive control information stored in the storage means are rewritten using an online external device. You can

According to the ninth means of the present invention, the drive control means synchronizes the operations of the external device and the image information storage means and the operations of the image information storage means and the display drive means. .

According to the tenth means of the present invention, the drive control means can always hold the drive control information as an initial value without any input from an external device.

[0036]

Embodiments of the present invention will be described below with reference to the drawings.

As a cell used in this embodiment, a cell having a sectional structure as shown in FIG. 3 was prepared and used. As shown in FIG. 3, this cell is provided with glass substrates 11a and 11b on which transparent electrodes 12a and 12b forming matrix electrodes are arranged so as to face each other, and sandwiched between these substrates and provided via the matrix electrodes. A ferroelectric liquid crystal 15 that can assume a first stable state and a second stable state in accordance with the applied electric field is provided. The liquid crystal material used here is a chiral smectic liquid crystal (SmC *, SmH).
*) Was used. Since this liquid crystal material has a twisted orientation of long sleeves of liquid crystal molecules when the layer thickness is large, this liquid crystal is sufficiently thin so that twisting of the molecules does not occur (for example, 1 to 3).
μm) It is arranged between layers.

Alignment films 14a and 14b are provided in contact with the liquid crystal 15, and these alignment films are rubbed with a cloth to align the molecules of the liquid crystal 15. This rubbing is performed by shifting the rubbing direction of the lower substrate by 190 degrees with respect to the rubbing direction of the upper substrate.

Polarizing plates 10a and 10b are arranged in crossed Nicols outside the glass substrates 11a and 11b, and control the light transmitted through the liquid crystal 15 layer. In addition, in order to control and keep the thickness of the liquid crystal layer 15 uniform, the alignment films 14a, 1a
A bead spacer 16 is arranged between 4b. Further, the transparent electrode 12 is disposed between the alignment films 14a and 14b and the transparent electrodes 12a and 12b with a liquid crystal 15 layer interposed therebetween.
Insulating films 13a and 13b are arranged for the purpose of preventing a short circuit between a and 12b.

In the liquid crystal panel according to this embodiment having the above-described cross-sectional structure, the liquid crystal material containing the pyrimidine component and having the characteristics shown in FIG. 21 was used as the ferroelectric liquid crystal material.

FIG. 4 is an example in which a cell is schematically drawn to explain the operation of the ferroelectric liquid crystal.

In FIG. 4, 21a and 21b are In ₂ O
A substrate (glass plate) covered with a transparent electrode made of a thin film of ₂ , SnO ₂ or ITO, and the SmC ^* (chiral smectic C) phase or SmH ^* (orientated so as to be perpendicular to the glass surface between the substrates. The liquid crystal of the chiral smectic H) phase is enclosed to form the liquid crystal molecular layer 22.

A thick line 23 represents a liquid crystal molecule, and the liquid crystal molecule 23 has a dipole moment 24 in a direction orthogonal to the liquid crystal molecule 23. When a voltage of a certain threshold value or more is applied between the electrodes on the substrates 21a and 21b, the helical structure of the liquid crystal molecules 23 is unraveled, and the dipole moment 24 is
The liquid crystal molecules 23 can change the alignment direction so that they are all oriented in the electric field direction. The liquid crystal molecule 23 has an elongated shape and exhibits refractive index anisotropy in the major axis direction and the minor axis direction thereof. For example, if crossed Nicols polarizers are placed above and below the glass surface, the voltage application polarity is It becomes a liquid crystal optical modulation element whose optical characteristics change depending on.

The surface-stable ferroelectric liquid crystal cell in the bistable orientation state used in this embodiment is exhibited by making the thickness sufficiently thin (for example, 1 μm to 3 μm). As shown in FIG. 5, as the liquid crystal layer is thinned, the helical structure of the liquid crystal molecules becomes untwisted even when no electric field is applied, and its dipole moment is
The state is either upward (34a) or downward (34b). When an electric field Ea or Eb having a polarity equal to or higher than a certain threshold is applied to such a cell by the voltage applying means 31a and 31b, the dipole moment corresponds to the electric field vector of the electric field Ea or Eb. It is oriented in either the upward direction 34a or the downward direction 34b. This inversion response occurs very quickly and exhibits bistability. Therefore, the liquid crystal molecules aligned in the first stable state 33a by applying the electric field Ea are stable even if the electric field is removed. In addition, when the electric field Eb in the opposite direction is applied, the liquid crystal molecules turn to the second stable state 33b,
Further, as in the case of being oriented in the first stable state, that state is maintained even if the electric field is removed. It should be noted that this liquid crystal exhibits driving qualities with respect to temperature as shown in FIG. 6 for display. For this reason, the display panel made of the liquid crystal is driven by changing the horizontal time and / or the driving voltage for one horizontal time depending on the temperature of the panel.

Next, driving of the present liquid crystal panel will be described in comparison with a conventional liquid crystal panel.

First, a conventional ferroelectric liquid crystal display system is shown in FIG. The display control device 62 supplies image information to the drive controller 51 in the display device 50. Here, the image information is a control signal (image data transfer clock), an address / data identification signal, and image data and a scan address supplied by the same signal line. On the other hand, the drive controller 51 sends the horizontal synchronization signal to the display controller 62.
Supply to

The display controller 62 is supplied with the horizontal synchronizing signal and supplies the scanning line address and the image data to the drive controller 51. The image data is stored in the volatile static random access memory for one line.

On the other hand, the scan address is once held in a volatile register and is used as the address of the common driver 55. At that time, the drive controller 51 selects the period of the horizontal synchronization signal based on the temperature information from the temperature sensor 52 so that the display on the display unit 56 whose response speed changes as shown in FIG. 6 does not break down. . For this horizontal synchronization period, a non-volatile read only memory stored in a format such as TTB shown in FIG. 19A is used.

In this way, the image data supplied from the display control device 62 is divided into even-numbered and odd-numbered segments and the segment driver I.D. C. It is supplied to 53 and 54, and is supplied to the transparent electrodes that are drawn in a zigzag pattern on the display 56 as a drive waveform generated from the drive timing and voltage selection code configured by four preset slots. At this time, the voltage of the drive waveform is determined by the temperature sensor 52.
Depending on the value of, the nonvolatile read-only memory is
A voltage value stored in a format such as VTB shown in FIG. 9 (b) is selected, and the segment driver I after transformation is selected from the power source controller installed in the drive controller 51.
C. 53, 54 are supplied. Also, common driver I.V. Similarly, C and 55 supply to the transparent electrode of the display device 56 the drive waveform generated from the drive timing and the power supply selection code configured by the preset four slots.

The display 56 is a ferroelectric liquid crystal display device, and is I connected to two scanning line extraction electrodes.
Ferroelectric liquid crystal having a bistable state is enclosed between glass plates provided with transparent electrodes such as TO, and a deflector is arranged in crossed Nicols with respect to the element. In addition, the pixel has 1024 scanning line electrodes and 5120 information line electrodes, which are 1024 ×.
It is composed of 5120 (dots). The pixels of this display panel are the segment drivers 53, 5 as described above.
4 and the common driver 55 are driven by the electric field generated by the drive waveform and are in the “bright” state or the “dark” state.
The status is displayed. In FIG. 9, W1 shows an example of the common drive waveform and segment drive waveform in the “dark” state, and W2 shows an example of the common drive waveform and segment drive waveform in the “bright” state. Is.

Now, the one-to-one image data transfer synchronization between the conventional display control device 62 and the ferroelectric liquid crystal display device 50 will be described with reference to FIG.

In FIG. 8, the horizontal synchronizing signal HSYNC
Defines the timing for transferring the image data DAT0 to DAT7 for one line from the display control device 62 to the display device 50. Since the period changes depending on the environment in which the display device 50 is placed, It is supplied from the display device 50 having the temperature sensor 52 to the display control device 62.

The image data DAT0 to DAT7 are transferred in 8-bit units in synchronization with the image data transfer clock CLK supplied from the display control device 62 to the display device 50.

The address / data identification signal AH / DL is
It is the supply timing of the scanning address indicating the scanning position of the image data of the display device 50 for one line to be transferred, and is supplied from the display control device 62 to the display device 50 in synchronization with the horizontal synchronization signal.

FIG. 10 shows the internal structure of the drive controller 51 shown in FIG.

In FIG. 10, the image information transfer timing control unit 100 has a function of converting the transfer rate and timing of image data into those suitable for the segment drivers 53 and 54. Then, the controlled image data is stored in the one-line memory by the image information storage control unit 103, read at a predetermined converted cycle, and supplied to the odd-numbered or even-numbered segment drivers 53 and 54.

The drive control unit 102 supplies the liquid crystal drive waveform generation timing (write timing for one line) for generating the drive waveform to the common driver 55 and the segment drivers 53 and 54.

The clock generator 1 (104) generates a clock signal which serves as a reference for the liquid crystal drive waveform generation timing. The clock generator 2 (105) includes the controller 51
Operation clock and image information transfer timing controller 1
00 reference clock is generated. The operation procedure control unit 101, which is responsible for the main control of these functions, uses the drive controller 51 according to a program stored in a non-volatile memory.
Control the operating procedure of.

FIG. 11 is a timing chart showing the horizontal synchronizing signal and the liquid crystal drive waveform generated by the drive controller 51 shown in FIG. Each waveform will be described with reference to FIGS. 10 and 11.

First, the operation procedure control unit 101 issues a command for converting the information from the temperature sensor 52 into a digital value to the analog / digital converter, and FIG.
A value corresponding to the time in the TTB table shown in (a) is set in the programmable counter.

The programmable counter is HSYNC.
When the signal goes low, the clock generator 1 (10
4) The clock counting is started. The counter repeats counting up to the value set by the operation procedure control unit 101, and the TIM
Generates an ER signal. This TIMER signal is supplied to the drive control unit 102 composed of a volatile memory. The signal is a liquid crystal drive waveform generation timing signal whose drive voltage is switched at each rising edge. Then, the drive control unit 102 sets the segment waveform level values SWFD0, 1 and the common waveform level values CWFD0, 1 to the segment drivers 53, 54 and the common driver 55, respectively.
Supply to The numerical values in the waveform are the numerical values shown in the drive voltage correspondence table shown in FIG. 11, and the voltage corresponding thereto is supplied to each driver.

The HT signal is low when the horizontal sync signal is low.
After reaching the level, it becomes low level at the first falling edge of the TIMER signal, and is set to high level again at the next falling edge of the TIMER signal.

The above SWFD0, 1 and CWFD0,
The segment drivers 53 and 54 and the common driver 55 are controlled by the signals 1, 1, TIMER, and HT.

The supply of the liquid crystal drive waveforms of the drivers 53, 54 and 55 to the liquid crystal element is started when the TIMER signal rises while the HT signal is at a low level. The voltage level of the liquid crystal drive waveform at that time is set to SWFD0, 1 and CWFD at the rising edge of each TIMER signal.
It is determined by the values of 0 and 1. The above operation is HSYN
The C signal is repeated every time it goes to a low level, and an image can be displayed on the internal synchronization type ferroelectric liquid crystal display device.

Next, driving of the ferroelectric liquid crystal panel according to this embodiment will be described.

This ferroelectric liquid crystal display system has the same transmission system as the conventional example shown in FIG. 7, except that lines for transmitting various drive control information to be described later are provided. The various kinds of drive control information referred to here are information of each item shown in FIGS. 13 to 18 of a register configured by a rewritable nonvolatile memory provided in the display device and a rewritable nonvolatile memory. Figure 19 for configured temperature compensation
Information relating to the tables shown in (a) and (b), information relating to the scanning order shown in FIG. 20, and the like. Since the drive control information is stored in a non-volatile memory such as a flash memory or an EPROM, it can be used even when the display device is used as a stand-alone device. It does not volatilize.

In addition to the drive control information as described above, the display control device 62 sends a control signal (image data transfer clock) to the drive controller 51 in the display device 50 as in the conventional example.
And image information including an address / data identification signal, and image data and a scan address supplied by the same signal line. The scanning address is stored as scanning information in the rewritable nonvolatile memory, and the image data is also stored in the rewritable nonvolatile memory in the same manner. In the present embodiment, the rewritable nonvolatile memory is limited to the capacity of 10 screens, but this is not a limitation. For example, it can be easily understood that increasing the capacity is advantageous for displaying a moving image.

On the other hand, the display device 51 supplies the horizontal synchronizing signal to the display control device 62. The display control device 62 is supplied with the horizontal synchronizing signal and supplies the scanning line address and the image data to the drive controller 51. At that time, the drive controller 51 selects the period of the horizontal synchronization signal based on the temperature information from the temperature sensor 52 so that the display on the display unit 56 whose response speed changes as shown in FIG. 6 does not break down. To do.

In this way, the image data supplied from the display control device 62 is distributed to even-numbered segment driver I.D. C. The display 5 as a drive waveform generated from the drive timing and the voltage selection code, which are supplied to 53 and 54 and are configured by the preset four slots.
6 is supplied to the transparent electrode drawn in a zigzag pattern.

The voltage of the driving waveform is determined by the temperature sensor 52.
Depending on the value of, the power controller combined with the drive controller 51 is transformed according to the table shown in VTB of FIG. 19B. This voltage is then applied to the segment driver I.V. C. 53, 54 are supplied. At this time, the drive voltage with respect to temperature is
It is stored as drive information in a non-volatile memory that can be rewritten online from the system 60. Also, common driver I.V. C. Similarly, 55 supplies the drive waveform generated from the drive timing and the power source selection code, which is also configured with four preset slots, to the transparent electrode of the display 56.

The display 56 is a ferroelectric liquid crystal display device, and is an IT connected to two scanning line extraction electrodes.
Ferroelectric liquid crystal having a bistable state is enclosed between glass plates provided with transparent electrodes such as O, and a deflector is arranged in crossed Nicols with respect to the element. The pixel is the scanning line electrode 102.
1024 × 5120 of 4 and information line electrodes 5120
(Dots). The pixels of this display panel are
As described above, the segment drivers 53, 54 and the common driver 55 are driven by the electric field generated by the drive waveforms, and are displayed in the "bright" state or the "dark" state.

In FIG. 9, W1 shows an example of the common drive waveform and the segment drive waveform in the "dark" state, and W2 shows an example of the common drive waveform and the segment drive waveform in the "bright" state. Is shown.

Next, the display control device 62 according to the present embodiment.
The one-to-one image data transfer synchronization between the ferroelectric liquid crystal display devices 50 will be described with reference to FIG.

In this embodiment, there is no difference in transmission of image information from the conventional example. That is, in FIG. 8, the horizontal synchronizing signal HSYNC is the image data DAT0 to DAT7 for one line from the display control device 62 to the display device 50.
Of the temperature sensor 52 because the time period changes depending on the environment in which the display device 50 is placed.
Is supplied to the display control device 62 from the display device 50 having the. The image data DAT0 to DAT7 are the image data transfer clock CL supplied from the display control device 62 to the display device 50.
It is transferred in 8-bit units in synchronization with K. The address / data identification signal AH / DL is a timing of supplying a scanning address indicating a scanning position of the display device 50 of the image data for one line to be transferred, and is synchronized with the horizontal synchronizing signal from the display control device 62 to the display device. 50.

Here, in the present embodiment, the display control device 6
2 among various information supplied to the display device 50, drive control information, that is, information about items of a drive information register configured by a rewritable nonvolatile memory, information about a temperature compensation table, and scanning. The information about the sequence is transmitted by serial transfer,
Other forms of transmission such as parallel transfer can also be used,
There are no restrictions on this transmission method.

FIG. 1 shows the internal structure of the drive controller 51 according to this embodiment.

First, the image information transfer timing control unit 20
0 synchronizes and arbitrates the writing of image data from the outside to the image storage control unit 206 composed of a nonvolatile memory that can be rewritten from the outside and the reading of the image data from the image storage control unit 206.

Further, in the scanning address storage control unit 208 composed of a non-volatile memory which can be rewritten from the outside, the scanning order corresponding to each frame stored in the image storage control unit 206 is as shown in FIG. Memorized in. In this embodiment, the storage capacity of the image storage control unit 206 is set to 10
Since the number of frames is set, the scan address storage control unit 208
Scan order information stored in SCAN1 to SCAN10
It is composed of 10 frames. Further, the image information timing control unit 200 has a function of converting the image data into a transfer rate and timing suitable for the segment drivers 53 and 54 according to the scanning order.

The image data displayed on the display unit 56 is supplied from the display control device 62, the image information timing control unit 200, the image storage control unit 206, the image information storage control unit 203, and the one-line memory. The image data stored online at the predetermined converted cycle and supplied to the odd-numbered or even-numbered segment drivers 53 and 54 and the non-volatile memory that can be rewritten in the stand-alone (offline) state. Image data supplied from the image storage control unit 206 configured.

The drive controller 202 sets the liquid crystal drive waveform generation timing (write timing of one line) read from the rewritable nonvolatile register for generating the drive waveform to the common driver 55 and the segment driver.
It is supplied to the drivers 53 and 54.

The clock generation 1 (104) generates a clock signal which serves as a reference for the liquid crystal drive waveform generation timing. The clock generator 2 (105) generates an operation clock for the drive controller 51 and a reference clock for the image information transfer timing controller 200.

The operation procedure control unit 201, which is in charge of the main control of these functions, controls the operation procedure of the drive controller 51 according to the program stored in the rewritable nonvolatile memory.

The initial value storage controller 207, which is a read-only memory, is used when the display device 50 does not hold the above-mentioned information to the memory. The registers used in these operations also include the horizontal synchronization counter register shown in FIG. The horizontal synchronization counter register is provided to change the scanning range when the pixel configuration (80 or 81) of the display device is different as shown in FIG. 12A or 12B.

FIG. 2 is a timing chart showing the horizontal synchronizing signal and the liquid crystal drive waveform generated by the drive controller 51 according to this embodiment shown in FIG. Each waveform will be described with reference to FIGS. 1 and 2.

First, the operation procedure control unit 201 issues a command for converting the information from the temperature sensor 52 to a digital value to an analog / digital converter, and is composed of a non-volatile memory which can be rewritten by the converted value. FIG. 19 (a)
A value corresponding to the time read from the temperature compensation table as shown in TTB shown in FIG. As this temperature compensation table, the one previously written in the memory online from the host system 60 or the one stored in the initial value storage control unit 207 is used.

The programmable counter is H
When the SYNC signal goes low, the clock generator 1
The counting of the clock of (104) is started. The counter is
Counting is repeated up to the value set by the operation procedure control unit 201 to generate the TIMER signal. The TIMER signal is supplied to the drive control unit 202 composed of a rewritable nonvolatile memory. The signal is a liquid crystal drive waveform generation timing signal whose drive voltage is switched at each rising edge. The drive control unit 202 then determines the segment waveform level values SWFD0, 1 and the common waveform level value CWF.
D0 and 1 are supplied to the segment drivers 53 and 54 and the common driver 55, respectively. The numerical values in the waveform are
The numbers shown in the drive voltage correspondence table shown in FIG.
A corresponding voltage is supplied to each driver.

The HT signal is a low horizontal sync signal.
After reaching the level, it becomes low level at the first falling edge of the TIMER signal, and is set to high level again at the next falling edge of the TIMER signal.

The above-mentioned SWFD0, 1 and CWFD0,
The segment drivers 53 and 54 and the common driver 55 are controlled by the signals 1, 1, TIMER, and HT.

The supply of the liquid crystal drive waveforms of the drivers 53, 54 and 55 to the liquid crystal element is started when the TIMER signal rises while the HT signal is at the low level. The voltage level of the liquid crystal drive waveform at that time is set to SWFD0, 1 and CWFD at the rising edge of each TIMER signal.
It is determined by the values of 0 and 1. The above operation is HSYN
This is repeated every time the C signal goes low. In this way, it is possible to display an image on the internal synchronization type ferroelectric liquid crystal display device in the online state or the offline state.

[0090]

According to the present invention, the ferroelectric liquid crystal display device can be displayed on-line in the related art, and is driven by writing control information, scan address and image data to the display device from the display control device. It is possible to change the conditions. Further, the control information and the image data are stored in a non-volatile memory when the power is cut off, and it is possible to independently and optimally display a still image and a moving image. As for the moving image display, since the scanning order is written in the nonvolatile memory corresponding to the image data, the multi-interlace scanning and the partial rewriting scanning can be performed by the stand-alone operation of the display device. The video display of can be optimally performed.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of a display device of the present invention.

FIG. 2 is a waveform diagram showing a timing of generating a drive waveform in synchronization with a horizontal scanning signal.

FIG. 3 is a sectional view of a ferroelectric liquid crystal display device.

FIG. 4 is an explanatory diagram schematically showing an example of a cell for explaining the operation of the ferroelectric liquid crystal.

FIG. 5 is an explanatory diagram of a surface-stabilized ferroelectric liquid crystal cell.

FIG. 6 is a characteristic diagram showing display qualities according to temperature of a ferroelectric liquid crystal.

FIG. 7 is a configuration diagram showing a configuration of a display system.

FIG. 8 is a waveform chart showing a transmission timing of image data between the display control device and the display device.

FIG. 9 is a waveform diagram showing a drive waveform W1 during dark display and a drive waveform W2 during bright display.

FIG. 10 is a configuration diagram showing a configuration of a conventional internal synchronous display device.

FIG. 11 is a waveform diagram showing a timing of generating a drive waveform in synchronization with a horizontal scanning signal.

FIG. 12 is an explanatory diagram showing a pixel configuration of ferroelectric liquid crystal.

FIG. 13 is an explanatory diagram showing a rewritable nonvolatile register configuration that constitutes a drive controller used in the display device of the present invention.

FIG. 14 is an explanatory diagram showing a rewritable nonvolatile register configuration that constitutes a drive controller used in the display device of the present invention.

FIG. 15 is an explanatory diagram showing a rewritable nonvolatile register configuration that constitutes a drive controller used in the display device of the present invention.

FIG. 16 is an explanatory diagram showing a rewritable nonvolatile register configuration that constitutes a drive controller used in the display device of the present invention.

FIG. 17 is an explanatory diagram showing a rewritable nonvolatile register configuration that constitutes a drive controller used in the display device of the present invention.

FIG. 18 is an explanatory diagram showing a rewritable nonvolatile register configuration that constitutes a drive controller used in the display device of the present invention.

FIG. 19 is a format configuration diagram of a temperature compensation table included in the drive controller of the display device.

FIG. 20 is a configuration diagram of a scan order table that stores scan addresses of the drive controller.

FIG. 21 is an explanatory diagram of characteristics of the liquid crystal material in the liquid crystal panel.

[Explanation of symbols]

10a Polarizing Plate for Analyzer 10b Polarizing Plate for Polarizer 11a Glass Substrate 11b Glass Substrate 12a Transparent Electrode 12b Transparent Electrode 13a Insulating Film 13b Insulating Film 14a Alignment Film 14b Alignment Film 15 Ferroelectric Liquid Crystal 16 Bead / Spacer 21a Substrate 21b Substrate 22 Liquid Crystal Molecule Layer 23 Liquid crystal molecule 24 Dipole moment 31a Substrate 31b Substrate 32 Liquid crystal molecule layer 33a First stable state 33b Second stable state 34a Upward dipole moment 34b Downward dipole moment 50 Display device 51 Drive controller 52 Temperature sensor 53 Segment / Driver 54 Segment driver 55 Common driver 56 Display device 60 Host system 61 Host computer 62 Display control device 80 Pixel structure of ferroelectric liquid crystal panel used in this embodiment 81 Image Configuration of Ferroelectric Liquid Crystal Panel Used in this Embodiment 100 Image Information Transfer Timing Control Unit 101 Operation Procedure Control Unit Comprised of Read Only Memory 102 Drive Control Unit Comprised of Random Access Memory 103 1-line image information storage control unit 104 composed of static random access memory 104 clock generation unit 1 105 clock generation unit 2 200 image information transfer timing control unit 201 of the present invention operation constituted by a rewritable nonvolatile register Procedure control unit 202 Drive control unit composed of rewritable nonvolatile register 203 1-line image information storage control unit composed of static random access memory AH / DL address / data identification signal CLK Image data transfer clock CWFD0 Common drive wave Power supply selection bit CWFD1 Common drive waveform power supply selection bit DAT0 to 7 Image data HSYNC Horizontal sync signal HT Drive waveform generation timing signal SCAN1 1 frame scan sequence table SCAN10 1 Frame scan sequence table SWFD0 Segment drive waveform power supply selection bit SWFD1 Segment drive waveform power supply selection Bit TIMR Waveform generated by programmable counter TTB Temperature compensation table (1 horizontal time) V1 Liquid crystal drive power source V2 Liquid crystal drive power source V3 Liquid crystal drive power source V4 Liquid crystal drive power source V5 Liquid crystal drive power source VC Liquid crystal drive common potential VTB Temperature compensation table (drive) Voltage) W1 Driving waveform at dark display W2 Driving waveform at bright display

Claims (10)

[Claims] 1. A liquid crystal panel in which a ferroelectric liquid crystal is sandwiched between glass substrates on which transparent electrodes are arranged, and the voltage applied to the transparent electrodes is changed by a driving means to align the molecules of the ferroelectric liquid crystal. An image based on image information supplied from an external device connected to the display device or an image stored in an internal image information storage means A display device comprising drive control means for displaying an image based on information on the display according to drive control information stored in a storage means. 2. The drive control information is a correspondence relationship between a temperature of the liquid crystal panel and a voltage waveform applied to the transparent electrode by the driving means, and the storage means is a nonvolatile memory with respect to power-off. A means as a means.
The display device according to claim 1. 3. The display device according to claim 1, wherein the image information storage unit is a storage unit that is non-volatile when power is cut off. 4. The display device according to claim 1, wherein the drive control information is a pixel configuration of the liquid crystal panel, and the storage unit is a storage unit which is non-volatile when power is cut off. . 5. The drive control information is a scanning order for each pixel in the liquid crystal panel, and the storage means is a non-volatile storage means with respect to power-off. Display device described. 6. The display device according to claim 1, wherein the image information storage means and the storage means are non-volatile rewritable storage means when power is cut off. 7. The display device according to claim 1, wherein the image information storage unit and the storage unit are flash memories or EPROMs. 8. The image information stored in the image information storage means and the drive control information stored in the storage means can be rewritten by an external device connected to the display device. The display device according to claim 1. 9. An image based on the image information stored in the image information storage means by synchronizing the writing operation of the image information storage means with the operation of the external device when rewriting the image information by the external device. 7. The drive control means further comprises a synchronization means for synchronizing the reading operation of the image information storage means and the operation of the drive means of the display when displaying the image on the display. 7. The display device according to 7. 10. The display device according to claim 7, wherein the drive control means further comprises an initial value storage means for storing an initial value of the drive control information.