JP3507707B2 - Liquid crystal display - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device using a ferroelectric liquid crystal, an antiferroelectric liquid crystal, etc.
The present invention relates to a liquid crystal display device having a liquid crystal layer made of a liquid crystal material of a chiral smectic C phase or a sub phase thereof sandwiched between a plurality of substrates.

[0002]

2. Description of the Related Art In recent years, in order to realize a low-cost color display device, a monochrome CRT (monochromatic Cathode Ray Tube) that does not require a shadow mask and requires only one electron gun has been developed.
Several methods of combining with a field sequential liquid crystal color shutter have been studied. Such a monochrome CRT
Is a CRT
Since the fluorescent screen of is solid and the system does not depend on the pixel pitch, there is an advantage that high definition can be easily achieved.
Further, there is also an advantage that it is easy to increase the size because high-precision materials and manufacturing methods are unnecessary. When color display is realized by the field sequential method, usually red (R)
In order to display three colors of green (G) and blue (B) for each frame of the display image, the standard value of the frame rate is 60 Hz.
It is driven by 180 Hz which is at least 3 times the frequency.

However, at a drive frequency of 180 Hz, when displaying a moving image, there is a problem that color breakup is visually recognized when the line of sight of the viewer moves or when the viewer blinks. . In order to solve this problem, a driving frequency of about 540 Hz, which is at least 9 times the standard value, is considered necessary. in this way,
In order to increase the driving frequency, the optical switching speed of the liquid crystal needs to be about 0.3 ms or less. However, such high-speed switching is not possible with nematic liquid crystal materials such as pi-cell which have been mainly used for liquid crystal shutters in the past.

Therefore, it is necessary to use a ferroelectric liquid crystal or an antiferroelectric liquid crystal which has spontaneous polarization and has a large torque due to an applied electric field and a high speed in place of the nematic liquid crystal material. A liquid crystal shutter using these liquid crystal materials (more generally, chiral smectic C phase or its sub-phase liquid crystal) utilizes a birefringence mode in which an optical axis parallel to the liquid crystal layer surface changes its direction by an electric field. It is driven by a method called. In the case of the simplest monochrome white and black binary display shutter, a cell is installed between neutral polarizing films arranged in crossed Nicols, and the optical axis is 0 degree and 45 degrees with respect to the polarizing axis of one polarizing film. The highest contrast can be obtained by designing the switching so that

In the case of a color shutter, a plurality of color polarizing films and a plurality of liquid crystal cells are used, but the arrangement of the optical axes of the liquid crystal cells with respect to the polarizing axes of the respective polarizing films is the same (Eurodisplay '84). digest, pp.7). In ferroelectric liquid crystals and antiferroelectric liquid crystals, the movement of molecules due to the electric field is limited to the conical surface.In a cell with a narrow gap, the switching angle in the liquid crystal layer is the cone angle of this cone. Corresponds almost, and is called a tilt angle ± 3
Most are 0 degrees or less. Therefore, 45
Tilt angle is ± 2
The material must be designed to be 2.5 degrees. Ferroelectric liquid crystals and anti-ferroelectric liquid crystals are designed to take bistable and tristable states in a cell with a narrow gap, and to stabilize two states with a tilt angle of ± 22.5 degrees. It is possible to

FIG. 15 shows an outline of driving of a conventional liquid crystal shutter using a ferroelectric liquid crystal or an antiferroelectric liquid crystal. FIG. 15 is a diagram showing an example of a drive sequence of the liquid crystal shutters and display colors. By inputting a voltage waveform with a period 1/180 seconds and an amplitude V as shown in 73 to 78 to each of the striped electrodes of the two liquid crystal cells 71 and 72 which are overlapped, a short black display period is provided between them. it can be a by have location to display the three colors of RGB in order. By setting the black display period to 1/3 of each color display period, the DC component of the voltage waveform can be eliminated. The counter electrode 14 was grounded to a constant potential. Scroll display is performed by inputting waveforms with shifted phases to the six divided stripe electrodes.

By the way, it is known that liquid crystals are easily affected by temperature fluctuations due to seasonal conditions and operating environments such as continuous use time. Further, the tilt angle also has temperature dependency, and the light extinction in the black state increases due to the change of the extinction position due to the temperature change, and the contrast decreases.
Further, it is difficult to finely adjust the deviation of the extinction position in an analog manner by the applied voltage in a bistable or tristable state such as a conventional ferroelectric liquid crystal or antiferroelectric liquid crystal material. Further, the long-time driving may cause the smectic layer to rotate accidentally, and the shift of the extinction position due to this may also cause the contrast reduction. Due to the asymmetrical driving waveform, the smectic layer rotation can be reversibly controlled.

However, as long as the generated layer rotation is driven with the same waveform, as it is driven for a long time, the layer rotation gradually progresses and the contrast continues to decrease, and eventually normal display becomes impossible. Further, since ferroelectric liquid crystals and antiferroelectric liquid crystals have piezoelectricity and electrostriction, when a liquid crystal cell is driven by a rectangular wave, a sound is generated at the time of polarity reversal. With the high-speed shutter as described above, several hundred Hz
There is also a problem that it becomes a vibration sound in the audible range and is not preferable as a display element.

As described above, when the conventional ferroelectric liquid crystal or anti-ferroelectric liquid crystal material is used, there is a problem in stability of contrast in a monochrome shutter, and there is a problem in stability of color purity in a color shutter. there were.

Furthermore, when a ferroelectric liquid crystal or an anti-ferroelectric liquid crystal is used, the capacity of the liquid crystal cell is increased by about one digit as compared with the case of a paraelectric liquid crystal such as Pi-cell, and therefore, in a large-sized display element. However, there is a problem that the time constant becomes large due to an increase in the resistance value of the wiring and the transparent electrode, and a sufficient response speed cannot be obtained in the central portion of the screen even when power is supplied from both ends of the screen. This makes it impossible to raise the drive frequency to 540 Hz, and it becomes difficult to avoid the occurrence of color breakup. In addition, there is a problem that alignment breakage and impact resistance are insufficient as a problem peculiar to the ferroelectric liquid crystal and the anti-ferroelectric liquid crystal.

[0011]

As described above, in the liquid crystal display device used for the conventional ferroelectric liquid crystal / antiferroelectric liquid crystal shutter, etc., first, when the liquid crystal cell is driven by a rectangular wave, it vibrates at high speed operation. There was a problem that sound was generated. Further, the monochrome shutter has a problem of stability of contrast, and the color shutter has a problem of stability of color purity. Further, there is a problem that the driving frequency cannot be increased and color breakage cannot be avoided.

According to the present invention, when used in a ferroelectric liquid crystal / anti-ferroelectric liquid crystal shutter, a high contrast which is stable as compared with the conventional one can be obtained due to a high speed operation, and when used in a color display device, a high color purity is obtained. It is an object of the present invention to provide a liquid crystal display device capable of reducing vibration noise even when the driving frequency can be increased.

[0013]

In order to achieve the above-mentioned object, a liquid crystal display device according to a first aspect of the present invention is arranged so as to face each other.
A plurality of substrates, a liquid crystal layer containing a liquid crystal material of a chiral smectic C phase or a sub-phase thereof sandwiched between the two substrates, a first electrode provided on one of the substrates, and a first electrode A second electrode provided on the other side of the substrate so as to face the first electrode, and the second electrode is provided on the liquid crystal layer as a difference in voltage applied to the first and second electrodes.
A holding voltage and a switching voltage are applied to the liquid crystal layer.
The holding voltage of one polarity and the other polarity for a time shorter than the liquid crystal response time before and after the polarity reversal of the voltage applied to
Voltage regulator comprising: a voltage holding means for continuing the application of constant holding voltage over a period of time of voltage application means for applying the switching voltage have any value up to the next polarity inversion between the holding voltage provided with a means, the one
The holding voltage of one polarity and the holding voltage of the other polarity are
The paired values are the same voltage, and the switching voltage is
The absolute value is lower than the holding voltage but the same value but different polarity.
It is characterized in that it is a voltage .

A liquid crystal display device according to a second aspect is the liquid crystal display device according to the first aspect, wherein the temperature detecting means for detecting a variation in temperature of the liquid crystal layer, or the first and second liquid crystal display devices.
Further comprising a current detecting means for detecting a change in the current supplied to the electrode, wherein the voltage adjusting means is responsive to the change in the temperature detected by the temperature detecting means or the change in the extinction position detected by the current detecting means. It is characterized by changing the switching voltage. By changing the switching voltage in this way, it is possible to suppress the fluctuation of the time required for switching the liquid crystal at the time of polarity reversal regardless of the temperature level, and to make the switching operation of the applied voltage always smooth.

A liquid crystal display device according to a third aspect of the present invention includes two substrates arranged to face each other, and a liquid crystal material of a chiral smectic C phase or a sub-phase thereof sandwiched between the two substrates. A liquid crystal layer, a first electrode provided on one side of the substrate, and a second electrode provided on the other side of the substrate facing the first electrode,
Temperature detecting means for detecting temperature fluctuation of the liquid crystal layer, or fluctuation of current supplied to the first and second electrodes
Current detection means for indirectly detecting the change in extinction position by
The temperature <br/> of variation of the liquid crystal layer detected by the temperature detecting means, or before detected by said current detecting means
Voltage applying means for applying a voltage while varying the switching voltage for inverting the polarity of the voltage applied to the liquid crystal layer as the difference of the voltages applied to the first and second electrodes in accordance with the serial extinction position variation And voltage holding means for continuing to apply a constant holding voltage to the first and second electrodes for a certain period until the next polarity inversion, and the first and second voltage adjusting means . Applied to electrodes
Applied to the liquid crystal layer as a difference in voltage
The holding voltage and the holding voltage of the other polarity have the same absolute value.
Voltage and the voltage applied to the first and second electrodes
The switching voltage applied to the liquid crystal layer as the difference between
The absolute value of the same value lower than the holding voltage
It is characterized by different voltages .

In the liquid crystal display device according to any one of the first to third modifications, the liquid crystal display device may compensate the temperature fluctuation or the extinction position fluctuation detected by the temperature detecting means or the current detecting means. The voltage applying means may be configured to adjust the voltage applied to the first and second electrodes.

A liquid crystal display device according to a fourth aspect is the liquid crystal display device according to any one of the first to third aspects,
The liquid crystal layer has an optical axis switching angle of at least 45 degrees at room temperature or lower, and the liquid crystal layer has no threshold antiferroelectric liquid crystal, strain-helical ferroelectric liquid crystal, and a polymer mixed with a ferroelectric substance. It is characterized by containing either a dielectric liquid crystal or an antiferroelectric liquid crystal.

A liquid crystal display device according to a fifth aspect is the liquid crystal display device according to any one of the first to third aspects,
In the liquid crystal layer, the first and second electrodes are composed of light-transmissive stripe-shaped electrodes, and metal auxiliary wiring is provided in a part of the stripe-shaped electrodes.
It is characterized in that the metal auxiliary wirings of two adjacent cells are provided so as to be displaced.

In the case of the above-mentioned claim 5, the IT
By installing the metal auxiliary wiring above or below the O electrode layer, the electrode resistance becomes lower than in the case where only the ITO transparent electrode is installed, so that an increase in the time constant can be avoided,
High-speed driving is possible even for large-sized display elements. The metal auxiliary wiring is hardly visually recognized by making the pixel size smaller than the pixel size of the monochrome display device on the back surface, and does not affect the display quality of the image. However, if it is extremely thin, the effect of lowering the resistance is small, and if it is thick, the wirings of the two cells overlap with each other depending on the viewing angle and are visually recognized to deteriorate the display quality. Therefore, by disposing the wirings of the two cells so as to be displaced as in this configuration, it is possible to enhance the effect of lowering the resistance without impairing the display quality.

Further, in the structure according to claim 5, a spacer wall having adhesiveness between the substrates may be provided at a position overlapping with the metal auxiliary wiring. In this way, if the spacer member having adhesiveness is installed at a position overlapping the opaque metal auxiliary wiring, the effect of improving the impact resistance can be achieved without visually recognizing the misalignment portion of the spacer portion or the spacer proximity portion. can get.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a liquid crystal display device according to the present invention will be described in detail below with reference to the accompanying drawings. The following embodiments are described for the purpose of facilitating the understanding of the present invention, and it goes without saying that various modifications and changes can be made without departing from the spirit of the present invention. .

First, a liquid crystal display device according to a first embodiment as a basic concept of the present invention will be described with reference to FIGS.
Will be described with reference to. FIG. 1 is a block diagram showing a schematic configuration of the liquid crystal display device according to the first embodiment. Figure 1
In FIG. 1, the liquid crystal display device includes a display unit 10 and a voltage adjusting unit 1 that supplies a drive voltage to the display unit 10. First, the display unit 10 includes two substrates 11 arranged to face each other. , 12, a liquid crystal layer 27 made of a liquid crystal material of a chiral smectic C phase or a sub-phase thereof sandwiched between these two substrates, and a first electrode 13 arranged in a predetermined state on the substrate. A second electrode 14 arranged in a predetermined state on the substrate so as to face the first electrode 13.
And have.

Next, the voltage adjusting means 1 uses the liquid crystal as a difference between the voltages applied to the first and second electrodes 13 and 14.
Voltage applying means 2 for applying a switching voltage having an arbitrary value between one holding voltage and the other holding voltage for a time shorter than the liquid crystal response time before and after the polarity reversal of the voltage 51 applied to the layer ; Voltage holding means 3 for continuously applying a constant holding voltage for a certain time until the polarity is reversed. Referring to FIG. 2, the voltage applying means 2 and the voltage
The operation of the holding means 3 will be described. The characteristic diagram in Figure 2
The two voltage holding characteristics are shown in the voltage level characteristic diagram shown in the upper row.
Four levels of pressure and two switching voltages are shown
There is. Since the voltage is 0V and the polarity is reversed, other than -12V
From one holding voltage to one holding voltage of + 12V
After the polarity is reversed, the voltage application means is a + 4V switch
Voltage is applied and the voltage level of + 12V is reached, the
The pressure holding means 3 holds one of the holding voltages at a voltage level of + 12V.
Hold. Next, after a predetermined period of 2 msec has passed,
Holding voltage + 12V to the other holding voltage level -12V
If the polarity is reversed during the period, it will switch to -4V.
Voltage is applied by the voltage applying means 2 and the other holding voltage is applied.
When the voltage reaches -12V, the voltage holding means 3 has a voltage of -12V.
The other holding voltage is held at the level. Of two holding voltages
The absolute value of the voltage level is 12 even if the polarity is positive and negative.
(| 12 |) and the levels of the two switching voltages
Has an absolute value of 4 (| 4 |) even if the polarity is positive or negative and inverted.
Has become. The voltage fluctuations that take these four levels are
This is the most basic operation of the present invention.

In the above structure, no measure is taken for the temperature change of the display section 10. However, in the liquid crystal display device, the temperature is relatively low when the power is turned on and the temperature is changed after continuous use. In the state where R is increased, it is more effective to change the way of supplying the switching voltage at the time of the polarity reversal. Therefore, a temperature detecting unit 36 as a sensor for detecting the temperature variation of the liquid crystal layer 27,
The temperature detecting means 4 for supplying the detection signal detected by the temperature detecting portion 36 to the voltage applying means 2 may be provided. The voltage applying unit 2 is configured to detect the temperature of the liquid crystal layer detected by the temperature detecting unit 4 according to the variation of the temperature of the liquid crystal layer.
The voltage is applied while changing the switching voltage for reversing the polarity of the voltage applied to the electrodes 13 and 14 of. The voltage holding means 3 continues to apply a constant holding voltage to the first and second electrodes 13 and 14 for a certain period until the next polarity reversal.

Further, instead of the temperature detecting means 4 for detecting temperature fluctuation, the first and second electrodes 13, 14 are provided.
The current detecting means 5 for detecting the fluctuation of the current supplied to the device may be provided. The voltage applying unit 2 compensates the fluctuation of the extinction position based on the current indirectly detected by the current detecting unit 5 so that the first and second electrodes 1 are compensated.
The applied voltage to 3, 14 is adjusted. The current detecting means 5 may be provided for the one including the temperature detecting means 4. Further, the voltage applying means 2 and the voltage holding means 3 of the voltage adjusting means 1 are supplied with a clock signal for switching the holding voltage at a constant cycle. Further, a read-only memory (ROM-Read Only Memory) that stores a reference temperature value or a reference current value that serves as a reference for obtaining the fluctuation range of the detected temperature fluctuation or extinction position fluctuation.
-) 6 is also provided.

The overall configuration of the liquid crystal display device according to the first embodiment having the above basic configuration will be described with reference to FIGS. 3 to 8. FIG. 3 shows the overall configuration of the liquid crystal display device according to the first embodiment. In FIG. 3, the liquid crystal display device 7 includes an input circuit 7A to which a VTR signal and AC power are supplied, and a CRT functioning as a drive and control circuit.
Circuit 8, a CRT 9 driven and controlled by the CRT circuit 8, a shutter circuit 1 functioning as a voltage adjusting unit, and a liquid crystal shutter 10 driven and controlled by the shutter circuit 1. .

As shown in FIGS. 4 and 5, the liquid crystal shutter 10 is composed of a front glass substrate 11 (22a) and a facing (back) glass substrate 12 (22b), and is manufactured by the following method. As the substrate material, a material other than glass, for example, polyether sulfone (PES)
It may be a plastic such as, and substrates of different materials and different thicknesses may be combined. Front substrate 11 (22a)
Is a non-alkali glass having a thickness of 1.1 mm, on which ITO stripe electrodes 13 (23a) having a thickness of 130 nm and formed in six horizontal stripes by a process of sputtering, photolithography and etching are formed. Has been done.

In FIG. 5, reference numerals 23a and 23b denote ITO electrodes on the front side and the back side, respectively.
The inorganic insulating films 24a on the front and back sides are sandwiched by 3b,
24b is provided, and the polyimide alignment films 25a, 2a on the front and back sides are sandwiched by the inorganic insulating films 24a, 24b.
5b is provided. Polyimide alignment film 25a, 25
Spherical spacers 26 are provided at regular intervals between b,
A liquid crystal layer 27 is provided by the spherical spacers 26. A metal auxiliary wiring 31 is provided on the ITO electrode 23a at a predetermined interval, and a spacer member 32 is provided at a position corresponding to the auxiliary wiring 31 in the liquid crystal layer 27.

In the above structure, first, the metal auxiliary wiring 3
By combining two liquid crystal shutters whose position and direction are different from each other by 45 ° in a positional relationship as shown in FIG. 6, a chromatic polarizing film is arranged between two cells and before and after to form a field sequential color shutter. Installed in front of the monochrome CRT, a color display device as schematically shown in FIG. 3 was obtained. The thin dark line formed by the opaque metal auxiliary wiring is hardly visible regardless of the viewing angle.
It was a level with no problems in practical use.

The metal auxiliary wiring 31 may be installed in parallel with the longitudinal direction of the stripe electrode so that the two cells do not overlap each other, as shown in FIG. FIG. 8 shows an example of a sectional view perpendicular to the longitudinal direction of the stripe electrode in this case. For example, when a PES substrate with a thickness of 0.1 mm is used as the substrate that constitutes the cell, 2
When the distance in the in-plane direction of the metal auxiliary wiring of one cell is 1 mm or more, the wirings do not overlap with each other at a viewing angle of 120 ° or more, and the interference is not visually recognized. In this case, the rubbing direction may be the direction shown in FIG. 7 or may be offset by 22.5 ° from the cell longitudinal direction as in FIG.

The normal operation of the liquid crystal display device according to the first embodiment as shown in FIGS. 3 to 8 is the same as the driving sequence of the conventional ferroelectric or antiferroelectric shutter described with reference to FIG. The liquid crystal shutter is driven according to the relationship with the display color. However, the waveform of the switching voltage is
As shown in FIG. 2, it is controlled so as to change in steps.

Next, a liquid crystal display device according to a second embodiment of the present invention will be described in detail with reference to FIGS. 9 and 10. FIG. 9 is a block diagram of a drive circuit for a color display device and a liquid crystal shutter in the liquid crystal display device according to the second embodiment. Perpendicular to the original RGB signal,
Control sync signal including horizontal sync signal (CL
K) is input, the control signal is converted to n times speed by the double speed conversion circuit 62 and is input to the driver of the CRT display unit 66 in accordance with the field cycle multiplied by n times. The RGB parallel signal is input to the driver as an RGB serial signal whose frequency is multiplied by n by the parallel-serial double speed conversion circuit 61, and desired RGB images are sequentially displayed at high speed.

On the other hand, a double speed control signal is input from the double speed conversion circuit 62 to the control circuit 63, and six phase drive signals for operating the liquid crystal color shutters are supplied to the liquid crystal cells 67 and 68.
Entered in. The temperature of the liquid crystal cell portion is detected by the temperature detector 64 and input to the control circuit 63.
The control circuit refers to the memory 65 in which the temperature-driving voltage conversion table is recorded, sets the driving voltage amplitude in FIG. 16 to a value according to the detected temperature, and outputs it to the liquid crystal cell.

FIG. 10 is a diagram showing an example of the driving sequence of the liquid crystal shutter and the display color in which the countermeasure against the vibration noise is taken. Each of the stripe electrodes of the two liquid crystal cells 71 and 72 to be overlapped has a period of 1/18 as shown in 73 to 78.
The point of inputting a voltage waveform of 0 second is the same as the example in FIG. 15, but in this example, the first 10 when the polarity is inverted.
The amplitude of the switching voltage Vi applied during 0 μs was made smaller than the amplitude of the holding voltage Vh. As a result, the optical response waveform became smooth, vibration noise was suppressed to a level at which practical problems did not occur, and a switching speed of 0.3 ms or less sufficient to obtain excellent display performance was obtained.

In order to reduce the vibration noise, it is also effective to reduce the switching voltage and to use a waveform different from the one-step step, for example, a multi-step step or taper waveform. However, the method of setting the switching voltage to a low value as in the second embodiment is the simplest and is preferable in terms of circuit configuration.

The color-developing means as the color display device may be not a color polarizing film but a dichroic dye mixed in the liquid crystal layer. In the case of the guest-host system of such a dye and liquid crystal, the liquid crystal cell is mixed with cyan, magenta, and yellow dyes, respectively.
It is preferable that the number of the cells is three, or the number of the three cells is two, and the number of the cells is six so that the absorption axes are orthogonal to each other. By optimizing the dichroic ratio and spectrum of the dye material according to the spectrum of the phosphor of the monochrome CRT, there is an advantage that a higher transmittance can be obtained as compared with the case of using a color polarizing film.

As the liquid crystal material, a non-threshold antiferroelectric liquid crystal, a strain helical ferroelectric liquid crystal, or a polymer, which is a smectic liquid crystal material whose optical axis direction changes substantially in proportion to an applied electric field, is mixed. Either the ferroelectric liquid crystal or the anti-ferroelectric liquid crystal is preferable. Since these have a characteristic that analog gradation display is possible, it becomes easy to compensate the shift of the extinction position by finely adjusting the applied voltage. Since the tilt angle decreases as the temperature rises, it is desirable to use the above liquid crystal material having a switching angle of at least 45 degrees at room temperature or a lower temperature range in order to obtain high contrast. As the threshold antiferroelectric liquid crystal, for example, a mixed liquid crystal shown in [Chemical formula 1] is known (J. Mater. Chem., Vol. 6, pp671 (1996)).

[0038]

[Chemical 1] As a strain-helical ferroelectric liquid crystal, for example, a mixed liquid crystal as shown in [Chemical Formula 2] is known (Japanese Patent Laid-Open No. 10-969).
No. 65).

[0039]

[Chemical 2] Ferroelectric liquid crystals mixed with polymers are, for example, Furue et al;
Reported by SID '98 Digest p-78. As a monomer to be mixed to form a polymer, for example, liquid crystal acrylate monomers (monoacrylate, diacrylate) shown in [Chemical Formula 3] are known.

[0040]

[Chemical 3] Ferroelectric liquid crystal has a cone angle close to 45 ° and is suitable for shutter applications. For example, CS manufactured by Chisso Petrochemical Co., Ltd.
-1011, CS-1014, CS-1026, CS-
1028 and the like are known. As the antiferroelectric liquid crystal, for example, MHPOBC as shown in [Chemical formula 4] is known, but it may be a mixed liquid crystal of a plurality of liquid crystal components including the antiferroelectric liquid crystal.

[0041]

[Chemical 4] As a comparative example of the second embodiment, a cell having no metal auxiliary wiring was prepared, the other conditions were the same as those of the second embodiment, a color shutter was configured, and a display device was prepared. The switching speed becomes slower toward the center of the screen and becomes 1 ms in the low temperature range or under the condition of a large cell of 40 inches or more.
The above becomes insufficient, and the problem of color breakage occurs in a color display device, and display unevenness also occurs, which is a level that cannot be put to practical use.

Next, two cells, each having a metal auxiliary wiring in the same position in parallel with the longitudinal direction of the stripe electrode, are formed into a second cell.
A display device was manufactured by a method similar to that of the embodiment, and two of them were combined to form a color shutter. High-speed response was achieved, and color breakup could be reduced to a level where there was no problem as a color display device, but depending on the viewing angle, the dark line of the metal auxiliary wiring may overlap between the two cells, and the dark line may be noticeable as an obstruction. The quality was lower than that of the liquid crystal display device of the second embodiment.

Next, a cell having no spacer wall at a position overlapping with the metal auxiliary wiring was prepared, and the other conditions were the same as those of the second embodiment, and the color shutter was configured to prepare a display device. Although the display performance was equivalent to that of the liquid crystal display device according to the second embodiment, the impact resistance was lower than that of the second embodiment, and the orientation test was likely to occur due to the impact test.

Next, a liquid crystal display device according to a third embodiment of the present invention will be described with reference to FIGS. 11 to 13. First, the structure of the liquid crystal cell will be described with reference to FIGS. 11 and 12. In FIG. 11, the liquid crystal cell is
It is composed of the front glass substrate 11 (22a) and the opposite (back) glass substrate 12 (22b), and is manufactured by the following method. On the front substrate 11 (22a), the thickness 130
An ITO stripe electrode layer 13 (23a) formed of 25 horizontal stripes of 25 nm is formed, and a SiO ₂ layer 24a is formed by sputtering to a thickness of 100 nm on the electrode layer 13 (23a). There is.

The opposite substrate has a thickness of 130 n over the entire surface except for the end portion.
The counter electrode layer 14 (23b) made of ITO is formed with a thickness of m, and a SiO ₂ layer having a thickness of 100 nm is formed on the electrode layer 14 (23b) by sputtering.
On the SiO ₂ layers 24a and 24B of each substrate, a low pretilt polyimide film 25 is formed as a liquid crystal alignment film.
a and 25b are formed to a thickness of 60 nm. The polyimide films 25a and 25b as the alignment film of each substrate are
Rubbing is performed in the direction opposite to the liquid crystal injection direction at an angle deviated from the longitudinal direction of the cell by 22.5 degrees. However, the rubbing axes of both substrates are shifted by about 10 degrees.

Then, a resin-coated silica spacer 26 is sprinkled to form a cell gap of 2.0 μm. At 25 ° C., a threshold antiferroelectric liquid crystal A having spontaneous polarization of 100 nC / cm ² , response time of 150 μs, saturation voltage of 15 V, tilt angle of 27 degrees (cone angle of 54 degrees) was used as a liquid crystal layer at 25 ° C. Two
Formed 7. The cone angle has a temperature dependence 41 as shown in FIG. Polarizing plates 21a and 21b are attached to the outsides of the glass substrates 22a and 22b, respectively. The polarization axes of the polarizing plate are denoted by reference numerals 15 and 16 in FIG.
The direction is as shown in.

As the polarizing plate, a neutral polarizing plate is used when it is used as a monochrome shutter, and a color polarizing plate is used when it is used as a color liquid crystal shutter. Since the extinction position detection unit 35 shown in FIG. 11 has a photodiode provided outside the neutral polarizing plate, the amount of transmitted light can be measured, and feedback is performed so that the amount of transmitted light is minimized during black display. It is connected to a mechanism that adjusts the drive voltage by controlling.

As the light source for detection, it is possible to use a signal light source such as a part of a monochrome CRT display, but it is also possible to install a detection light source independent of such a signal light source. . Further, the light source for detection can be made to blink so as to have a constant light amount at the time of detection, or the light amount at the time of detection can be separately detected and standardized. Further, it is sufficient to perform the detection once every several tens of seconds to several minutes. By using a mechanism including such detecting means and voltage adjusting means, the voltage is adjusted so that the optical axis direction of the liquid crystal when a positive voltage is applied matches the polarization axis direction 16 of one of the polarizing plates. . That is, the voltage is adjusted so that the switching angle does not depend on the temperature-dependent characteristics as indicated by the broken line 43 in FIG.

The drive system driven by the applied voltage has a maximum applied voltage of ± 15V. A rectangular wave having an amplitude of 10 to 15 V adjusted as described above is input to each stripe electrode 13 and the counter electrode 14 is grounded to maintain a constant potential. As a monochrome shutter, the black state is good without depending on the temperature, and as shown by the solid line 44 in FIG. 13, a high numerical value such that the contrast ratio is always “200: 1” was obtained. Further, when used as a color shutter, high color purity can be obtained, and by combining with a monochrome CRT, a high quality image display device as a display element can be obtained.

Depending on the combination of the alignment film and the liquid crystal material,
Extinction position shift may occur due to rotation of the smectic layer due to long-term use, but fluctuation detection means for detecting the fluctuation of extinction position or fluctuation of temperature and fluctuation of extinction position or temperature fluctuation detected by this fluctuation detection means By providing a feedback mechanism including a voltage adjusting unit that adjusts the voltage applied to the first and second electrodes so as to compensate, the drive waveform is adjusted and the liquid crystal layer is rotated in the opposite direction, and Since a force for returning the extinction position to the initial layer normal direction works, it is possible to suppress the occurrence of the extinction position shift even after long-term use.

Next, a liquid crystal display device according to the fourth embodiment of the present invention will be described with reference to FIGS. 11, 12 and 14. In FIG. 11, the liquid crystal cell includes a front glass substrate 11 (22a) and a facing (back) glass substrate 12 (22).
b) and manufactured by the following method.
The substrate material may be a material other than glass, for example, plastic such as PES, or a combination of different materials and substrates having different thicknesses. The front substrate 11 (22a) is a 1.1 mm-thick non-alkali glass, on which ITO stripe electrodes having a thickness of 130 nm and formed into 25 horizontal stripes by sputtering, photolithography, and etching processes. 13 (23a) is formed.

The distance between the stripe electrodes 13 is about 20 μm. On the entire surface of the ITO stripe electrode 13, a 100 nm thick SiO ₂ film is formed as an insulating layer over the entire surface.
The film 24a is formed by sputtering. Other materials for forming the insulating layer include SiN and Ta ₂
O ₅ , SrTiO ₃ , TiO _{2 and the} like are considered, and this insulating film may be a single layer film or a multilayer film. The counter substrate 12 is a 1.1 mm-thick non-alkali glass, and a counter electrode 14 (23b) of ITO having a thickness of 130 nm is formed on the entire surface except the end portion by a process of sputtering, photolithography, and etching. is doing.

A SiO ₂ film 24 having a thickness of 100 nm is formed on the entire surface of the ITO stripe electrode 13.
b was formed by sputtering. SiO ₂ layers 24a, 2 of each substrate
Low-pretilt polyimide films 25a and 25b having a thickness of 60 nm were respectively formed on 4b as liquid crystal alignment films. Other than this, polyvinyl alcohol, polyamideimide, or the like may be used as the liquid crystal alignment film. The alignment film on each substrate was rubbed in the direction opposite to the liquid crystal injection direction at an angle deviated from the cell longitudinal direction by 22.5 degrees. However, the rubbing axes of both substrates were shifted by about 10 degrees in consideration of the difference between the rubbing direction and the liquid crystal smectic layer normal. Further, on the front substrate 11, spherical silica spacers 26 coated with a resin having a diameter of 2.0 μm were dispersed.

The material of the spherical spacer may be hard plastic or adhesive.
Further, the adhesive spacer and the non-adhesive spacer may be mixed and scattered. An epoxy adhesive for bonding was applied to the opposite substrate on the peripheral portion and fixed under heat and pressure to form a cell. As the liquid crystal material, there was used spontaneous polarization 100 nC / cm ^{2 at} 25 ° C., response time 150 μs, saturation voltage 15 V, threshold anti-ferroelectric liquid crystal A with tilt angle 27 ° (cone angle 54 °), and liquid crystal layer was formed by vacuum injection. 27 was formed. The liquid crystal material is preferably a ferroelectric liquid crystal or antiferroelectric liquid crystal that does not have hysteresis or memory property, and for example, there are strain-helix type ferroelectric liquid crystal and polymer mixed ferroelectric liquid crystal. Depending on the case, a liquid crystal having hysteresis may be used.

The injection method may be another method such as suction injection. Outside the glass substrates 22a and 22b,
Polarizing films 21a and 21b were attached, respectively. The polarization axis of the polarizing film was in the directions indicated by arrows 15 and 16 in FIG. The polarizing film is a neutral polarizing film when used as a monochrome shutter, and a color polarizing film when used as a color shutter. In order to improve the color range characteristics and viewing angle characteristics,
A retardation film may be used in addition to the polarizing film.

A drive system having a maximum applied voltage of ± 20 V was used. A voltage according to the drive waveform 51 shown in FIG. 2 was applied to each stripe electrode 13. In the waveform 51, the switching voltage when the polarity is inverted has an amplitude of 4V and the holding voltage is 12V. The counter electrode 14 was grounded to a constant potential. As a result,
The optical response waveform 52 became smooth and the vibration noise was suppressed to a level at which there was no practical problem, and a switching speed of about 0.3 ms sufficient to obtain excellent display performance was obtained.

Further, in order to compensate the temperature dependence of the switching angle of the liquid crystal, for example, the switching voltage is about 20V at a low temperature of 0 ° C to 10 ° C, and the switching voltage is about -5V at a high temperature of 50 ° C to 60 ° C. Thus, the switching voltage may be continuously changed according to the temperature.
A temperature sensor, an indirect sensor by detecting a switching current peak having temperature dependency, or the like can be used to detect the temperature. As a result, the vibration sound is suppressed without depending on the temperature, and as a monochrome shutter, the black state is good without depending on the temperature, and the contrast ratio is always 200 :.
A value as high as 1 was obtained.

By combining the two liquid crystal shutters,
A color polarizing film was arranged between the two cells and before and after the cell to form a field sequential color shutter, which was installed in front of the monochrome CRT to obtain a color display device. A buffer material was used to fix the cells, and vibration-proof silicon grease was injected between the two cells. The shutter part can be driven at a high speed of 9 times or more of the display image of 60 Hz, and the vibration noise can be reduced to a level without problems.
Almost no color breakage was observed, high color purity was obtained for a color shutter, and a display element combined with a monochrome CRT realized high-quality image display.

As a comparative example of the liquid crystal display device according to the fourth embodiment, a cell was prepared under the same conditions as in the fourth embodiment. The applied voltage is adjusted according to the temperature dependence of the switching angle of the liquid crystal, and a driving waveform 53 as shown in FIG. 16A is formed as a simple rectangular wave having the same switching voltage and holding voltage.
When driven by, the optical response showed a sharp switching characteristic with a response time of about 0.2 ms as shown by the waveform 54. The switching speed became insufficient in the low temperature range, and the vibration noise was generated in the high temperature range, which was a level that could not be put to practical use.

Further, by adjusting the holding voltage according to the temperature dependence of the switching angle of the liquid crystal, FIG.
As shown in (b), when driving was performed with the drive waveform 55 in which the switching voltage was set higher than the holding voltage at any temperature, the optical response showed a sharp switching time of about 0.1 ms as shown by the waveform 56. Became a characteristic. Although a sufficient switching speed was obtained from the low temperature region to the high temperature region, the vibration noise was loud especially in the high temperature region, which was a level that could not be put to practical use.

Next, a liquid crystal display device according to the fifth embodiment of the present invention will be described with reference to FIGS. 11 to 13. The liquid crystal display device according to the fifth embodiment has a third
Since the basic configuration is similar to that of the liquid crystal display device according to the embodiment, the basic configurations of FIGS. 11 and 12 are substantially the same, and redundant description will be omitted. Only different points will be described. Although the liquid crystal display device according to the third embodiment detects the extinction position of the liquid crystal layer and adjusts the applied voltage, the liquid crystal display device according to the fifth embodiment uses the temperature dependence of the optimum drive voltage as data in advance. It is characterized in that the driving voltage is adjusted by detecting the temperature of the liquid crystal layer and comparing it with the data.

First, the difference in the basic structure will be described. In the third embodiment, the number of stripe electrodes is 25, but in the liquid crystal device according to the fifth embodiment, the stripe electrode 13 (23a) is used. ) Is five. Further, as the type of liquid crystal used, the threshold anti-ferroelectric liquid crystal A having a response time of 150 μs and a tilt angle of 27 degrees (cone angle 54 degrees) was used in the first embodiment. In the response time 120
Distorted spiral ferroelectric liquid crystal B having a tilt angle of 25 degrees (cone angle of 50 degrees) at μs is used.

Further, as described above, as the feedback mechanism for adjusting the voltage applied to the electrodes, which is the greatest feature of the fifth embodiment, the temperature of the optimum drive voltage that minimizes the amount of transmitted light during black display is used. The dependency is prepared as data in advance, and as shown in FIG.
The temperature is detected by the temperature detection unit 36 provided at any position of No. 3, and the drive voltage is adjusted based on the detected temperature.

In the liquid crystal display device according to the third embodiment, extinction position detection means 35 is provided as detection means,
In the liquid crystal display device of the second embodiment, the temperature detecting means 3
However, the present invention is not limited to this, and as in the liquid crystal display device according to the fifth embodiment with the same configuration shown in FIG. It may be configured to include both the means 36. With such a configuration, it becomes possible to more accurately detect and adjust the deviation of the driving voltage.

Two comparative examples will be described in order to explain the operational effects of the liquid crystal display devices according to the third to fifth embodiments. First, as a first comparative example, a cell was prepared under the same conditions as in the first embodiment except that an antiferroelectric liquid crystal used in a shutter having a box-shaped hysteresis and having a memory property was used. The liquid crystal display device was driven under the same conditions as in the first embodiment. According to the first comparative example, in the case of the monochrome shutter, the black state was insufficient depending on the temperature, and the contrast varied from 200 to 50 depending on the temperature. Further, in the case of a color shutter, there is a problem that the color purity is lowered depending on the temperature.

The antiferroelectric liquid crystal according to the first comparative example has temperature dependence of the cone angle (see reference numeral 42 in FIG. 4) and has a characteristic that analog gray scale display is impossible. It is impossible to adjust the extinction position by adjusting the voltage to obtain the switching angle as shown by the broken line 43 in FIG. 13, and the contrast ratio is greatly reduced as shown by the curve 45 in FIG. did.

As a second comparative example, a node was formed under the same conditions as the liquid crystal display device according to the first embodiment, and driving was performed with the same voltage amplitude regardless of temperature. According to this second comparative example, in the case of the monochrome shutter, the black state was insufficient and the contrast decreased from 200 to 50. Further, in the case of the color shutter, the color purity was remarkably lowered depending on the temperature. Temperature dependence of cone angle even with anti-ferroelectric liquid crystal that can display analog gradation
However, if the extinction position is not adjusted by adjusting the applied voltage, the switching angle as shown by the broken line 43 in FIG. 13 cannot be obtained, which is similar to that shown by the curve 45 in FIG. It can be seen that the contrast ratio is significantly reduced due to the temperature characteristics of.

Next, a liquid crystal display device according to the sixth embodiment will be described with reference to FIGS. 4, 5 and 14. The liquid crystal cell shown in FIGS. 4 and 5 has a front glass substrate 11
(22a) and the opposite (back side) glass substrate 12 (22b), and were manufactured by the following manufacturing method. As a substrate material, besides glass, polyether sulfone (PE
Plastics such as S) and polycarbonate (PC) may be used, and substrates of different materials and different thicknesses may be combined. The front substrate 11 (22a) is a non-alkali glass having a thickness of 1.1 mm, and the thickness of the front substrate 11 (22a) is 13 by a process of sputtering, photolithography and etching.
It has ITO stripe electrodes 13 (23a) formed in six horizontal stripes of 0 nm.

The distance between the stripe electrodes is about 20 μm. On the ITO electrode layer 13 (23a), a plurality of metal auxiliary electrode wirings 31 having a width of 20 μm are formed in the longitudinal direction for each ITO stripe electrode. As the metal electrode material, a single layer or a multi-layer film of Al, CI, Mo, Mo-Ta is preferable, and the position of the wiring may be below the ITO electrode. On the entire surface of the ITO electrode and the metal electrode, an SiO ₂ layer having a thickness of 100 nm is formed as an insulating layer.
Layer 24a was sputter deposited. Other materials for the insulating layer include SiN, Ta ₂ O ₅ , SrTiO ₃ and TiO _2.
It may be a single layer or a multilayer film.

A photosensitive resin was applied on the insulating layer to a thickness of 2 μm, and a portion other than the portion corresponding to the portion where the metal electrode was formed was removed by photolithography to form a spacer wall. The counter substrate is a non-alkali glass having a thickness of 1.1 mm, and a counter electrode 14 (23b) of ITO having a thickness of 130 nm is formed on the entire surface except the end portion by a process of sputtering, photolithography and etching. There is. The metal auxiliary electrode wiring may be formed on the ITO electrode layer 14 (23b) as in the case of the front substrate. In this embodiment, since the power supply ends of the counter electrodes are upper and lower, the wiring direction is vertical. A direction substantially orthogonal to the wiring direction of the front substrate is preferable.

A silicon oxide film 24b having a thickness of 70 nm is formed on the entire surface of the ITO stripe electrode 13 by sputtering to form a SiO ₂ layer 24 of each substrate.
Low-pretilt polyimide films 25a and 25b, each having a thickness of 30 nm, were formed as liquid crystal alignment films on a and 24b by offset printing and firing at a temperature of about 180 to 250 ° C. Other than this, polyvinyl alcohol, polyamideimide, or the like may be used as the liquid crystal alignment film. The alignment film on each substrate was rubbed at an angle deviated from the cell longitudinal direction by 22.5 degrees in the direction opposite to the liquid crystal injection direction. However, the rubbing axes of both substrates were shifted by about 10 degrees in consideration of the difference between the rubbing direction and the liquid crystal smectic layer normal.

Alignment of the liquid crystal that is likely to be generated in the layer direction by arranging the metal auxiliary wiring that becomes the step on the substrate surface or the spacer member that becomes the wall in parallel or perpendicular to the normal direction of the smectic layer of the liquid crystal Since it becomes possible to minimize defects, it is desirable that the rubbing direction and the spacer wall direction be substantially parallel or substantially vertical. Spherical silica spacers 26 coated with a resin having a diameter of 20 μm were scattered on the front substrate. The material of the spherical spacer may be hard plastic or adhesive.

Further, adhesive spacers and non-adhesive spacers may be mixed and scattered. An epoxy adhesive for bonding was applied to the opposite substrate on the peripheral portion and fixed under heat and pressure to form a cell. As a liquid crystal material, a liquid crystalline acrylate monomer U manufactured by Dainippon Ink and Chemicals, Inc.
An antiferroelectric liquid crystal CS-4001 manufactured by Chisso Co. containing 5 wt% of CL-001 was used to form a liquid crystal layer 27 by vacuum injection, and then ultraviolet light having an intensity of 2 mW / cm 2 was irradiated for 10 minutes. The monomers were polymerized to form a polymer network in the liquid crystal layer.

As the liquid crystal material having a high speed property, a ferroelectric liquid crystal or an antiferroelectric liquid crystal having no hysteresis or memory property is preferable. For example, a strain-helix type ferroelectric liquid crystal or a ferroelectric substance mixed with a polymer is used. Although there are liquid crystals and the like, liquid crystals having hysteresis may be used in some cases. The injection method may be another method such as suction injection. Polarizing films 21 are provided outside the glass substrates 22a and 22b, respectively.
a and 21b were attached. The polarization axis of the polarizing film is 1.
The directions indicated by 5 and 16 were used.

As the polarizing film, an achromatic polarizing film is used when used as a monochrome shutter, and a chromatic polarizing film is used when used as a color shutter. A retardation film may be used in addition to the polarizing film in order to improve the color range characteristics and the viewing angle characteristics. The drive system used had a maximum applied voltage of ± 20V. A rectangular wave voltage having an amplitude of 12 V was applied to the terminals at both ends of each stripe electrode 13. The counter electrode 14 was grounded to a constant potential. As a result, the electrode resistance is 10Ω / due to the metal auxiliary wiring.
A switching speed of about 0.3 ms, which is sufficient to obtain excellent display performance, was obtained in the cell central portion even under the condition of □ or less and corresponding to a cell size of 40 inches or more. Further, the impact resistance is improved by the effect of the spacer wall installed at the position of the metal auxiliary wiring.

The operation of the liquid crystal display device according to the sixth embodiment will be described. FIG. 14 shows a memory 65 in FIG.
FIG. 5 is a diagram showing an example of drive voltage amplitude correction data depending on the temperature of a liquid crystal shutter, which is recorded in FIG. By optimizing the drive voltage V in FIG. 15 and the holding voltage Vh in FIG. 10 as shown in Vh in FIG. 14, the temperature dependence of the switching angle of the slow axis of the liquid crystal is eliminated.
The switching voltage in FIG. 10 is represented by Vi in FIG.
By optimizing as shown in (1), the temperature dependence of the switching speed of the liquid crystal is eliminated, and it is possible to constantly reduce the vibration noise. As in this example, the switching voltage may be set higher than the holding voltage in the low temperature range. As the temperature detector, in addition to a general temperature sensor that uses a resistance change of a semiconductor, an indirect sensor that detects a delay time or a peak value of a switching current peak having temperature dependency can be used.

As a result of the above-described structure, the driving of the shutter portion can be performed by lowering the resistance of the electrode by the metal auxiliary wiring.
High-speed driving of a display image at 60 Hz, which is 9 times faster or more, is possible, almost no color breakage is observed, high color purity is obtained independent of temperature, and high-quality image display is realized.

[0078]

As described in detail above, according to the present invention,
Compared to conventional monochrome shutters or color display devices that use ferroelectric liquid crystal / anti-ferroelectric liquid crystal, high-speed operation provides stabler high contrast and higher color purity, and also reduces vibration noise. It will be possible. Further, according to the present invention, as compared with a monochrome shutter or a color display device using a conventional ferroelectric liquid crystal / anti-ferroelectric liquid crystal, high-speed operation is possible even in a large size without impairing display quality, Color breakage is eliminated and impact resistance is improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is a waveform characteristic diagram showing the performance of the liquid crystal display device of the first embodiment.

FIG. 3 is a block plan view showing the outline of the entire color display device in the first embodiment.

FIG. 4 is a plan view showing a liquid crystal cell that constitutes a liquid crystal shutter in the first to sixth embodiments.

FIG. 5 is a sectional view showing a sectional structure of a liquid crystal cell which also constitutes a liquid crystal shutter.

FIG. 6 is a perspective view showing a positional relationship between two cells which also constitute the liquid crystal shutter.

FIG. 7 is a perspective view showing a positional relationship between two cells which also constitute the liquid crystal shutter.

FIG. 8 is a cross-sectional view showing the positional relationship between the auxiliary wiring and the spacer wall of two cells which also constitute the liquid crystal shutter.

FIG. 9 is a block diagram showing a drive circuit for a color display device and a liquid crystal shutter in a liquid crystal display device according to a second embodiment of the present invention.

FIG. 10 is a plan view showing drive sequences and display colors of a liquid crystal shutter together with waveforms in the second embodiment.

FIG. 11 is a plan view showing a planar structure of a liquid crystal shutter portion in the liquid crystal display device according to the third to fifth embodiments.

12 is a sectional view showing a sectional structure of the liquid crystal shutter portion shown in FIG.

FIG. 13 is a characteristic diagram showing an optical response of the liquid crystal display device according to the third to fifth embodiments of the present invention under comparison with a conventional response.

FIG. 14 is a characteristic diagram showing drive voltage amplitude correction data depending on the temperature of a liquid crystal shutter in the liquid crystal display device according to the sixth embodiment.

FIG. 15 is a plan view showing a driving sequence and a display color of a conventional liquid crystal shutter together with waveforms.

16A is a waveform characteristic diagram showing a drive waveform and an optical response of a conventional liquid crystal shutter, and FIG. 16B is a waveform characteristic diagram showing a drive waveform and an optical response of a conventional liquid crystal shutter.

[Explanation of symbols]

1 Voltage Adjusting Means 2 Voltage Applying Means 3 Voltage Holding Means 4 Temperature Detecting Means 5 Current Detecting Means 7 Display 7A Input Circuit 8 CRT Circuit 9 Monochrome CRT 10 Display 11 Front Side Glass Substrate 12 Back Side Glass Substrate 13 ITO Stripe Electrode 14 ITO Solid electrode 15 Polarization axis of polarizing plate on front side 16 Polarization axis of polarizing plate on back side, optical axis direction of liquid crystal layer when positive voltage is applied 17 Optical axis direction of liquid crystal layer when negative voltage is turned on 18 Pouring port 19 Seal 21a, 21b front side, back side polarizing plates 22a, 22b front side, back side glass substrates 23a, 23b front side, back side ITO electrodes 24a, 24b front side, back side inorganic insulating films 25a, 25b front side, back side polyimide alignment film 26 spacer 27 liquid crystal layer 31 metal auxiliary wiring 32 spacer member 35 extinction position detector 36 temperature detectors 51, 53, 55 drive waveform 52, 4,56 optical response

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G02F 1/133 560 G09G 3/36

Claims (5)

(57) [Claims] 1. A liquid crystal layer comprising two substrates which are arranged opposite to each other, a liquid crystal material containing a liquid crystal material of a chiral smectic C phase or a sub phase thereof sandwiched between the two substrates, and the liquid crystal layer is provided on one of the substrates. And a second electrode provided on the other side of the substrate facing the first electrode, the applied voltage to the first and second electrodes. As the difference between
A holding voltage and a switching voltage are applied to the liquid crystal layer,
The scan take any value between the holding voltage and the other of the holding voltage of the polarity of the polarity inversion short time only one polarity than the liquid crystal response time before and after the voltage applied to the liquid crystal layer <br / > A voltage adjusting means including a voltage applying means for applying an itching voltage and a voltage holding means for continuously applying a constant holding voltage for a certain period until the next polarity reversal is provided .
To the one polarity of the holding voltage and the other polarity of the holding voltage
Is a voltage whose absolute value is the same, and said switching voltage
Is the same value whose absolute value is lower than the holding voltage and has the same polarity.
The liquid crystal display device is characterized by different voltages . 2. A temperature detecting means for detecting a temperature change of the liquid crystal layer, or a current detecting means for indirectly detecting a change of the extinction position by a change of a current supplied to the first and second electrodes. the voltage adjustment means to claim 1, characterized in that changing the switching voltage in response to said detected extinction varies with the temperature variation, or the current detection means detected by said temperature detecting means The described liquid crystal display device. 3. One of the substrates is provided with two substrates arranged opposite to each other, a liquid crystal layer containing a liquid crystal material of a chiral smectic C phase or a sub-phase thereof sandwiched between the two substrates. And a second electrode provided on the other side of the substrate so as to face the first electrode, and a temperature detecting means for detecting temperature fluctuation of the liquid crystal layer. , Or fluctuations in the current supplied to the first and second electrodes
Current detection means for indirectly detecting the change in extinction position by
The temperature <br/> of variation of the liquid crystal layer detected by the temperature detecting means, or before detected by said current detecting means
Voltage applying means for applying a voltage while varying the switching voltage for inverting the polarity of the voltage applied to the liquid crystal layer as the difference of the voltages applied to the first and second electrodes in accordance with the serial extinction position variation When provided with a voltage regulating means comprising a voltage holding means for continuing the application of constant holding voltage to the first and second electrodes over a period of time until the next polarity inversion, the said first and second As the difference in the voltage applied to the electrodes
Holding voltage of one polarity applied to the liquid crystal layer and the other polarity
Is a voltage whose absolute value is the same as that of the first voltage.
And the difference between the voltages applied to the second electrode is printed on the liquid crystal layer.
The absolute value of the applied switching voltage is the holding
A liquid crystal display device , which has the same value lower than the voltage but different polarities . 4. The liquid crystal layer has an optical axis switching angle of at least 45 degrees at room temperature or a lower temperature range, and the liquid crystal layer has no threshold antiferroelectric liquid crystal, strain helical ferroelectric liquid crystal, polymer. 4. The liquid crystal display device according to claim 1, further comprising one of a ferroelectric liquid crystal and an antiferroelectric liquid crystal in which is mixed. 5. The first and second electrodes are formed of light-transmissive stripe-shaped electrodes, and metal auxiliary wiring is provided in a part of the stripe-shaped electrodes,
4. The liquid crystal display device according to claim 1, wherein the metal auxiliary wirings of two adjacent liquid crystal cells are provided so as to be displaced from each other.