WO2008062744A1 - Elément d'affichage à cristaux liquides - Google Patents
Elément d'affichage à cristaux liquides Download PDFInfo
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- WO2008062744A1 WO2008062744A1 PCT/JP2007/072353 JP2007072353W WO2008062744A1 WO 2008062744 A1 WO2008062744 A1 WO 2008062744A1 JP 2007072353 W JP2007072353 W JP 2007072353W WO 2008062744 A1 WO2008062744 A1 WO 2008062744A1
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- liquid crystal
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- ferroelectric liquid
- display element
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
- G09G3/3611—Control of matrices with row and column drivers
- G09G3/3648—Control of matrices with row and column drivers using an active matrix
- G09G3/3651—Control of matrices with row and column drivers using an active matrix using multistable liquid crystals, e.g. ferroelectric liquid crystals
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1337—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1337—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
- G02F1/13378—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers by treatment of the surface, e.g. embossing, rubbing or light irradiation
- G02F1/133788—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers by treatment of the surface, e.g. embossing, rubbing or light irradiation by light irradiation, e.g. linearly polarised light photo-polymerisation
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/137—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering
- G02F1/139—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering based on orientation effects in which the liquid crystal remains transparent
- G02F1/141—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering based on orientation effects in which the liquid crystal remains transparent using ferroelectric liquid crystals
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1337—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
- G02F1/133711—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers by organic films, e.g. polymeric films
- G02F1/133723—Polyimide, polyamide-imide
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1337—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
- G02F1/133773—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers the alignment material or treatment being different for the two opposite substrates
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2300/00—Aspects of the constitution of display devices
- G09G2300/04—Structural and physical details of display devices
- G09G2300/0421—Structural details of the set of electrodes
- G09G2300/0426—Layout of electrodes and connections
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2310/00—Command of the display device
- G09G2310/02—Addressing, scanning or driving the display screen or processing steps related thereto
- G09G2310/0235—Field-sequential colour display
Definitions
- the present invention relates to a liquid crystal display element using monostable ferroelectric liquid crystal having spontaneous polarization.
- Liquid crystal display elements are thin and have low power consumption, etc., and their features have expanded their applications from large displays to portable information terminals, and their development is actively underway.
- liquid crystal display devices have been developed and put into practical use, such as TN, STN multiplex drive, active matrix drive using thin layer transistors (TFTs) in TN, these are nematic liquid crystals! / For this reason, it cannot be said that the response speed of the liquid crystal material is sufficiently compatible with moving image display that is slow, such as several ms to several tens of ms.
- Ferroelectric liquid crystal is a liquid crystal suitable for high-speed devices whose response speed is as short as ⁇ s.
- Ferroelectric liquid crystals are widely known as bistable ones proposed by Clark and Lagerwool, which have two stable states when no voltage is applied (Fig. 14 top), but in two states, bright and dark. Although it is limited to switching and has memory characteristics, gradation display is not possible! /, And! /, Have problems!
- the ferroelectric liquid crystal undergoes a phase change with the cholesteric phase (Ch) —smectic A (SmA) phase and irrus metatic C (SmC *) phase in the temperature-falling process, and passes through the SmA phase.
- Some materials show S mC * phase (Fig. 13 bottom).
- the majority of materials have a phase sequence that passes through the SmA phase compared to the former that does not pass through the SmA phase.
- Ferroelectric liquid crystals having a phase sequence via the latter SmA phase usually have two stable states with respect to a single-layer normal and are known to exhibit bistability.
- color liquid crystal display elements have been actively developed.
- a color filter method and a field sequential color method for realizing color display.
- a white light source is used as a backlight
- a color display is realized by attaching an R′G′B micro color filter to each pixel.
- the field sequential color system switches the backlight to R'G'B 'R'G'B---in time, and opens and closes the black and white shutter of the ferroelectric liquid crystal in synchronization with it.
- the color is temporally mixed by the afterimage effect of the film, thereby realizing color display.
- This field sequential color system allows color display with one pixel and eliminates the need for using a color filter with low transparency, enabling bright and high-definition color display, and realizing low power consumption and low cost. Useful in that it can.
- the liquid crystal as a black and white shutter needs to have high-speed response in order to obtain good moving image display characteristics. If a ferroelectric liquid crystal is used, this problem can be solved.
- the ferroelectric liquid crystal used in this case is particularly capable of displaying gray scales by analog modulation and exhibiting monostability in order to realize high-definition color display. desirable.
- FIG. 15 shows an example of a driving sequence of a liquid crystal display element by a field sequential color method using TFT elements.
- the voltage applied to the liquid crystal display element is 0 to Sat V (V)
- data write scan is performed with a positive polarity voltage
- data erase scan is performed with a negative polarity voltage. It shows monostability and has either positive or negative polarity
- a ferroelectric liquid crystal that responds only to a certain voltage is used.
- Driving a ferroelectric liquid crystal using a TFT element is performed by applying a certain voltage to the common electrode of the common electrode substrate facing the TFT substrate and applying a voltage to the pixel electrode of each pixel of the TFT substrate.
- a positive polarity voltage is applied when the pixel electrode voltage is relatively high
- a negative polarity voltage is applied when the pixel electrode voltage is relatively low.
- positive polarity voltage application (writing) and negative polarity voltage application (erasing) are performed alternately.
- TFT elements When TFT elements are used, voltage cannot be written to all pixels at the same time, so scanning is performed line by line. For this reason, the writing of the first line and the writing of the L line are out of timing. The same applies to erasing. In the example shown in FIG. 15, erasing is performed from the first line after all lines have been written.
- + (R) indicates that the writing scan was performed in synchronization with the R (red) backlight, and-(R) was synchronized with the R backlight. Indicates that it has been erased and scanned (voltage sign of negative polarity).
- + (G), one (G), + (B), and-(B) also indicate that they have run in synchronization with the G (green) and B (blue) backlights, respectively.
- the ferroelectric liquid crystal responds by performing the write scan and the erase scan in synchronization with the time switching of the backlight R'G'B '.
- both the first line write scan (+ (R)) and the L line write scan (+ (R)) are in a bright state while the R backlight is on. It becomes.
- the write scan (+ (R)) and erase scan (one (R)) are shifted in time between the first line and the L line.
- the erasing scan (1 (R)) of the L line synchronized with the R backlight results in a bright state when the G backlight is lit (bold frame in FIG. 15).
- the L line erase scan one (G) synchronized with the G backlight results in a bright state when the B backlight is lit. (Thick frame in Fig. 15).
- Ferroelectric liquid crystals are difficult to align because they have higher molecular ordering than nematic liquid crystals.
- double domain two regions having different layer normal directions (hereinafter referred to as “double domain”) are generated (the upper part of FIG. 13).
- double domain becomes a big problem because the display is reversed in black and white during driving. For this reason, various alignment treatment methods have been studied!
- an electric field applied slow cooling method in which a liquid crystal cell is heated to a temperature equal to or higher than the cholesteric phase and gradually cooled while a DC voltage is applied (see Non-Patent Document 2).
- the force S can be controlled by controlling the direction of spontaneous polarization according to the direction of the applied electric field.
- this method again, If the temperature rises above the phase transition point, alignment disorder occurs, and the manufacturing process becomes complicated, causing problems such as alignment disorder where the electric field between the pixel electrodes does not act.
- a fixed liquid crystal layer (reactive property) is formed by applying a reactive liquid crystal to one of the upper and lower alignment films, and aligning and fixing the liquid crystal.
- a liquid crystal layer is formed and this fixed liquid crystal layer acts as an alignment film.
- the reactive liquid crystal is relatively similar in structure to the ferroelectric liquid crystal, so that the interaction with the ferroelectric liquid crystal becomes stronger, so that the alignment is more effective than when only the alignment film is used.
- the ferroelectric liquid crystal can be aligned without causing alignment defects such as double domains.
- the direction of spontaneous polarization of the ferroelectric liquid crystal cannot be known unless it is actually driven.
- Patent Document 1 JP 2005-208353 A
- Patent Document 2 Japanese Patent Laid-Open No. 2005-234549
- Patent Document 3 Japanese Patent Laid-Open No. 2005-234550
- Patent Document 4 Japanese Patent Laid-Open No. 2005-258428
- Non-Patent Document 1 ⁇ , ⁇ ⁇ , LI, J., OGAWA, A., HORNUNG, ⁇ ⁇ , SCHMIDT, W.,
- Non-Patent Document 2 PATEL, J., and GOODBY, JW, 1986, J. Appl. Phys., 59, 2355. Disclosure of the Invention Problems to be solved by the invention
- the present invention has been made in view of the above-described problems. Compared to a liquid crystal display element using a ferroelectric liquid crystal exhibiting monostability, the direction of spontaneous polarization of the ferroelectric liquid crystal The main object is to provide a liquid crystal display element capable of controlling the above.
- the present invention provides a first substrate, a first electrode layer formed on the first substrate, a rubbing film formed on the first electrode layer, and A first alignment treatment substrate having a first alignment film, a second substrate, a second electrode layer formed on the second substrate, and photodimerization formed on the second electrode layer.
- a second alignment processing substrate having a second alignment film that is a photo-alignment film using a photodimerization-type material that imparts anisotropy to the alignment film by causing a reaction, the first alignment film and the second alignment film
- a liquid crystal display device which is disposed so as to face an alignment film and sandwiches a ferroelectric liquid crystal between the first alignment film and the second alignment film, wherein the ferroelectric liquid crystal is When the voltage is applied so that the second electrode layer is negative, the molecular orientation of the ferroelectric liquid crystal is in the first alignment treatment.
- the first alignment film which is a rubbing film
- the second alignment film which is a photo-alignment film using a photodimerization type material
- the first alignment film which is a rubbing film
- the second alignment film which is a photo-alignment film using a photodimerization type material
- the rubbing film preferably contains polyimide.
- the first alignment treatment substrate is a TFT substrate having a thin film transistor (TFT) formed on the first base material
- the second alignment treatment substrate is the second electrode.
- the layer is a common electrode substrate, which is a common electrode. This is because it is possible to prevent light leakage from occurring near the gate electrode when the TFT element switch is off.
- the liquid crystal display element of the present invention is an active matrix method using thin film transistors. It is preferable that it is driven by a formula. This is because by adopting an active matrix method using TFT elements, the target pixel can be reliably turned on and off, enabling high-quality displays.
- the liquid crystal display element of the present invention is preferably driven by a field sequential color system! /.
- the above ferroelectric liquid crystal is monostable, so it can display gray scales, and is driven by the field sequential color method to achieve a bright, high-definition color video with a wide viewing angle with low power consumption and low cost. This is the power to realize the display.
- the first alignment film side that is a rubbing film is used. Taking advantage of the tendency of the spontaneous polarization of the ferroelectric liquid crystal to be suitable, the direction of the spontaneous polarization of the ferroelectric liquid crystal can be controlled.
- FIG. 1 is a schematic diagram showing the behavior of liquid crystal molecules.
- FIG. 2 is a schematic cross-sectional view showing an example of a liquid crystal display element of the present invention.
- FIG. 3 is a schematic diagram showing an example of the alignment state of a ferroelectric liquid crystal.
- FIG. 4 is a schematic view showing another example of the alignment state of the ferroelectric liquid crystal.
- FIG. 5 is a schematic view showing spontaneous polarization of a ferroelectric liquid crystal.
- FIG. 6 is a schematic view showing another example of the alignment state of the ferroelectric liquid crystal.
- FIG. 7 is a schematic sectional view showing another example of the liquid crystal display element of the present invention.
- FIG. 8 is a diagram showing a driving sequence of a liquid crystal display element by a field sequential color method.
- FIG. 9 is a schematic perspective view showing another example of the liquid crystal display element of the present invention.
- FIG. 10 is a schematic diagram showing another example of the alignment state of the ferroelectric liquid crystal.
- FIG. 11 is a schematic diagram showing another example of the alignment state of the ferroelectric liquid crystal.
- FIG. 12 is a graph showing a change in transmittance with respect to an applied voltage of a ferroelectric liquid crystal.
- FIG. 13 is a diagram showing a difference in orientation due to a difference in phase sequence of a ferroelectric liquid crystal. 14] This is a graph showing the change in transmittance of ferroelectric liquid crystal against applied voltage.
- FIG. 15 is a diagram showing a driving sequence of a liquid crystal display element by a field sequential color method.
- a liquid crystal display element in which a ferroelectric liquid crystal was sandwiched between a rubbing film and a photo-alignment film using a photodimerization type material was produced.
- a 1 ⁇ 5 am bead spacer was sprayed on one substrate, and a sealant was applied to the other substrate with a seal dispenser. Next, both substrates were made to face each other so that their respective alignment treatment directions were parallel, and thermocompression bonding was carried out to produce an empty liquid crystal cell.
- a ferroelectric liquid crystal (trade name: R2301, manufactured by AZ Electronic Materials) is used to attach a ferroelectric liquid crystal to the top of the injection port, and an oven is used to determine the N-phase isotropic phase transition temperature. Injection was performed at a temperature 10 ° C to 20 ° C higher, and the temperature was slowly returned to room temperature.
- the ferroelectric liquid crystal was sandwiched between the rubbing film and the photo-alignment film using the photodimerization material in the same manner as described above by changing the types and combinations of the polyimide and the photodimerization material.
- the same result as above was obtained.
- Two glass substrates on which ITO electrodes are formed are each spin-coated with a 2% by weight cyclopentanone solution of photodimerization type material (Rolic technologies, product name: ROP103), and 130 minutes at 130 ° C. After drying, alignment treatment was performed by irradiating with linearly polarized ultraviolet rays of about lOOmj / cm 2 .
- a 1.5 mm bead spacer was sprayed on one substrate, and a sealant was applied to the other substrate with a seal dispenser. Next, both substrates were made to face each other so that their respective alignment treatment directions were parallel, and thermocompression bonding was carried out to produce an empty liquid crystal cell.
- a ferroelectric liquid crystal (trade name: R2301, manufactured by AZ Electronic Materials) is used to attach a ferroelectric liquid crystal to the top of the injection port, and an oven is used to determine the N-phase isotropic phase transition temperature. Injection was performed at a temperature 10 ° C to 20 ° C higher, and the temperature was slowly returned to room temperature.
- liquid crystal display element of the present invention will be described in detail.
- the liquid crystal display element of the present invention comprises a first substrate, a first electrode layer formed on the first substrate, and a first alignment film formed on the first electrode layer and being a rubbing film.
- the first alignment film and the second alignment film are opposed to each other with a second alignment treatment substrate having a second alignment film that is a photo-alignment film using an optical dimerization-type material that imparts anisotropy to the alignment film.
- a liquid crystal display element having a ferroelectric liquid crystal sandwiched between the first alignment film and the second alignment film, wherein the ferroelectric liquid crystal exhibits monostability.
- the molecular direction of the ferroelectric liquid crystal is in relation to the first alignment-treated substrate surface. It is characterized in that the line is to vary by about 2 times the tilt angle of the ferroelectric liquid crystal.
- the ferroelectric liquid crystal used in the present invention exhibits monostability, and when a voltage is applied so that the second electrode layer becomes a negative electrode, the molecules of the ferroelectric liquid crystal The direction changes approximately twice the tilt angle of the ferroelectric liquid crystal in parallel to the first alignment treatment substrate surface.
- the ferroelectric liquid crystal is rotated along a ridge line of a cone in which the liquid crystal molecules 1 are inclined from the layer normal z and have a bottom surface perpendicular to the layer normal z. To do. In such a cone, the tilt angle of the liquid crystal molecule 1 with respect to the layer normal z is called the tilt angle ⁇ .
- shown monostability means a state in which the state of the ferroelectric liquid crystal when no voltage is applied is stabilized in one state.
- the liquid crystal molecule 1 can operate on a cone between two states inclined by a tilt angle ⁇ with respect to the layer normal z. 1 is stable in any one state on the cone The state that has become.
- FIG. 2 is a schematic sectional view showing an example of the liquid crystal display element of the present invention.
- the second alignment process substrate 16 on which the second electrode layer 14 and the second alignment film 15 are sequentially formed is opposed to the first alignment film 5 of the first alignment process substrate 6 and the second alignment process substrate 16.
- a ferroelectric liquid crystal is sandwiched between the second alignment film 15 and the liquid crystal layer 10 is formed.
- the first alignment film 5 is a rubbing film
- the second alignment film 15 is a photo-alignment film using a photodimerization type material. Further, the first alignment film 5 and the second alignment film 15 are arranged so that their alignment treatment directions are parallel to each other.
- the first alignment film which is the rubbing film
- the first alignment film has a strong strength. It was found that the spontaneous polarization of the dielectric liquid crystal tends to be suitable. This is thought to be due to the polar surface interaction, which is the interaction between the ferroelectric liquid crystal and the first alignment film surface and the second alignment film surface.
- the second alignment film has a relatively positive polarity in the first alignment film, which is a rubbing film, and the second alignment film, which is a photo-alignment film using a photodimerization type material. Therefore, when no voltage is applied, the spontaneous polarization Ps of the liquid crystal molecules 1 tends to face the first alignment film 5 side due to the polar surface interaction, as illustrated in FIG. In FIG. 3, the first base material and the second base material are omitted, and the liquid crystal molecules are shown for the ferroelectric liquid crystal.
- the voltage is affected by the polarity of the applied voltage. Then, the spontaneous polarization Ps of the liquid crystal molecules 1 comes to face the second alignment film 15 side.
- the first base material and the second base material are omitted.
- the first electrode layer is a negative electrode (one) and the second electrode layer is a positive electrode (+), as shown in FIG.
- the spontaneous polarization Ps of 1 comes to face the first alignment film 5 side.
- the direction of spontaneous polarization is no voltage applied It becomes the same as the state.
- the direction of spontaneous polarization is such a direction because the direction of spontaneous polarization is the direction in which the polarization of the ferroelectric liquid crystal and the polarization of the alignment film or the polarity of the voltage are electrically balanced. This is because the state becomes stable.
- a liquid crystal display element using a ferroelectric liquid crystal two opposing alignment films are arranged so that their alignment treatment directions are parallel to each other.
- the liquid crystal molecules 1 are aligned along the alignment treatment direction d of the first alignment film and the second alignment film as illustrated in FIG. A uniform orientation state is obtained.
- the spontaneous polarization Ps The direction of is reversed. Also in this case, the liquid crystal molecules 1 are in a uniform alignment state.
- the spontaneous polarization Ps is caused by the influence of the polarity of the applied voltage as illustrated in Fig. 6 (a).
- the direction of is reversed.
- the liquid crystal molecules 1 are in the same alignment state as in the case where no voltage is applied.
- Fig. 6 (a) is a schematic diagram showing the alignment state of the liquid crystal molecules from the top surface of Fig. 3, and the spontaneous polarization Ps is directed from the front side to the back side (X in Fig. 6 (a)). mark).
- Fig. 6 (b) is a schematic diagram showing the alignment state of the liquid crystal molecules from the upper surface of Fig. 4, and the spontaneous polarization Ps is directed toward the front of the paper (Fig. 6 (b)). ⁇ mark).
- the alignment of the ferroelectric liquid crystal without causing alignment defects can be monostabilized. sand That is, the ferroelectric liquid crystal exhibits monostability. Further, since the ferroelectric liquid crystal is aligned without using the electric field applied slow cooling method, the alignment can be maintained even if the temperature is raised above the phase transition temperature, and the occurrence of alignment defects can be suppressed.
- the second electrode layer is a negative electrode
- the first alignment processing is performed. It is assumed that polarizing plates 17a and 17b are provided on the outside of the substrate 6 and the second alignment treatment substrate 16, respectively, so that light is incident from the polarizing plate 17a side and light is emitted from the polarizing plate 17b side.
- the two polarizing plates 17a and 17b have their polarization axes substantially perpendicular to each other, and the polarization axis of the polarizing plate 17a and the alignment treatment direction of the first alignment film 5 (the alignment direction of the liquid crystal molecules) are substantially parallel. It is arranged to be.
- the polarized light becomes elliptically polarized light due to the birefringence of the liquid crystal molecules.
- the elliptically polarized light only linearly polarized light that coincides with the polarization axis of the polarizing plate 17b is transmitted through the polarizing plate 17b and becomes bright.
- the liquid crystal display element provided with the polarizing plate as described above, when the voltage is not applied and when a negative polarity voltage is applied to the first electrode layer, the first electrode layer It becomes bright when a positive polarity voltage is applied. Therefore, when the liquid crystal display device is driven by the field sequential color method, as shown in Fig. 8, for example, when the G (green) backlight is lit, the scanning is synchronized with the R (red) backlight. Therefore, it is possible to avoid the bright state.
- the rubbing film can realize a higher pretilt angle than the photo-alignment film. Therefore, by using the rubbing film, it is possible to control the generation of zigzag defects and hairpin defects with the power S.
- the photo-alignment film has been subjected to photo-alignment treatment. Since the photo-alignment treatment is a non-contact alignment treatment, it is advantageous in that it can control the quantitative alignment treatment without generating static electricity and dust. It is for. Furthermore, the photodimerization type material has the advantage that the exposure sensitivity is higher than other materials used for the photo-alignment film, for example, the photoisomerization type material.
- a rubbing film is used for the first alignment film and a photo-alignment film using a photodimerization type material is used for the second alignment film, it is easy to impart anisotropy to the second alignment film.
- a liquid crystal display element free from alignment defects such as zigzag defects and hairpin defects can be obtained.
- the liquid crystal display element of the present invention can be driven by an active matrix method using a thin film transistor (TFT).
- the first alignment processing substrate is a TFT substrate having a TFT formed on the first base material
- the second alignment processing substrate is the second electrode layer as a common electrode.
- a common electrode substrate is preferable.
- Figure 9 is a schematic perspective view showing an example of an active matrix liquid crystal display element using TFTs.
- the liquid crystal display element 2 illustrated in FIG. 9 includes a TFT substrate (first alignment treatment substrate) 6 in which TFT elements 25 are arranged in a matrix on a first base material 3, and a second base material 13. And a common electrode substrate (second alignment processing substrate) 16 on which a common electrode (second electrode layer) 14 is formed.
- a gate electrode 24x, a source electrode 24y, and a pixel electrode (first electrode layer) 4 are formed on the TFT substrate (first alignment processing substrate) 6, .
- the gate electrode 24x and the source electrode 24y are arranged vertically and horizontally, respectively, and by applying a signal to the gate electrode 24x and the source electrode 24y, the TFT element 25 can be operated to drive the ferroelectric liquid crystal.
- a portion where the gate electrode 24x and the source electrode 24y intersect with each other is insulated by an insulating layer (not shown), and the signal of the gate electrode 24x and the signal of the source electrode 24y can operate independently.
- a portion surrounded by the gate electrode 24x and the source electrode 24y is a pixel that is a minimum unit for driving the liquid crystal display element of the present invention.
- Each pixel includes at least one TFT element 25 and a pixel electrode (first electrode). 1 electrode layer) 4 is formed. Then, by sequentially applying a signal voltage to the gate electrode and the source electrode, the TFT element of each pixel can be operated.
- the liquid crystal layer and the first alignment film are omitted.
- the TFT element switch when the gate electrode is set to a high potential of about 30 V, the TFT element switch is turned on, the signal voltage is applied to the ferroelectric liquid crystal by the source electrode, and the gate electrode is set to about 10 V.
- the TFT element switch When the low potential is applied, the TFT element switch is turned off.
- the switch-off state as illustrated in Fig. 10, a voltage is applied between the common electrode (second electrode layer) 14 and the gate electrode 24x so that the common electrode (second electrode layer) 14 side is positive. Is done.
- the ferroelectric liquid crystal does not operate, so that the pixel is in the ⁇ state.
- the spontaneous polarization of the liquid crystal molecules tends to face the first alignment substrate due to the polar surface interaction. That is, in the switch-off state, as illustrated in FIG. 10, the spontaneous polarization Ps of the liquid crystal molecules 1 faces the TFT substrate (first alignment treatment substrate) 6 side. Therefore, the direction of spontaneous polarization is not affected by the voltage applied between the common electrode (second electrode layer) 14 and the gate electrode 24x.
- the spontaneous polarization is directed toward the common electrode substrate (second alignment substrate) when no voltage is applied, the effect of the voltage applied between the common electrode and the gate electrode in the switch-off state
- the direction of spontaneous polarization is reversed in the vicinity of the region where the gate electrode is provided. Then, in the vicinity of the region where the gate electrode is provided, the ferroelectric liquid crystal operates and light leakage occurs even though the switch is off.
- the direction of spontaneous polarization is not affected by the voltage applied between the common electrode and the gate electrode, so that no light leakage occurs. Therefore, in the present invention, light leakage near the gate electrode can be prevented by controlling the direction of spontaneous polarization and using the second alignment substrate as a common electrode substrate.
- the ferroelectric liquid crystal used in the present invention exhibits monostability, and when a voltage is applied so that the second electrode layer is a negative electrode, the molecular direction of the ferroelectric liquid crystal is the surface of the first alignment treatment substrate. In parallel, the tilt angle of the ferroelectric liquid crystal changes approximately twice.
- the molecular direction of the ferroelectric liquid crystal is approximately equal to the tilt angle ⁇ of the ferroelectric liquid crystal with respect to the first alignment treatment substrate surface.
- ⁇ Twice change '' means that the liquid crystal molecules are stabilized in one state on the cone when no voltage is applied, and the liquid crystal molecules are monostable when a voltage is applied so that the second electrode layer is a negative electrode.
- the liquid crystal molecules maintain the mono-stabilized state or the second state from the mono-stabilized state.
- the tilt angle from the mono-stabilized state of the liquid crystal molecules when the voltage is applied so that the voltage is applied so that the electrode layer is negative and the second electrode layer is negative is When a voltage is applied so that the second electrode layer is a positive electrode, the liquid crystal molecules are inclined from the mono-stabilized state. It is larger than the oblique angle.
- FIG. 11 is a schematic diagram showing an example of the alignment state of a ferroelectric liquid crystal exhibiting monostability.
- Fig. 11 (a) shows no voltage applied
- Fig. 11 (b) shows a voltage applied so that the second electrode layer becomes negative
- Fig. 11 (c) shows that the second electrode layer becomes positive.
- the cases where voltage is applied to are shown.
- the liquid crystal molecule 1 stabilizes in one state on the cone. (Fig. 11 (a)).
- a voltage is applied so that the second electrode layer is a negative electrode
- the liquid crystal molecules 1 are tilted from the stabilized state (broken line) to one side (FIG. 11 (b)).
- the liquid crystal molecule 1 when a voltage is applied so that the second electrode layer is a positive electrode, the liquid crystal molecule 1 is in a stable state (dashed line) when a voltage is applied so that the second electrode layer is a negative electrode. Tilts to the opposite side (Fig. 11 (c)). At this time, the inclination angle ⁇ when the voltage is applied so that the second electrode layer becomes the negative electrode is larger than the inclination angle ⁇ when the voltage is applied so that the second electrode layer becomes the positive electrode.
- d represents the orientation direction
- z represents the layer normal.
- the direction of the liquid crystal molecule 1 is a force S that changes approximately twice the tilt angle ⁇ (angle 2 ⁇ ) parallel to the first alignment processing substrate surface, where The change in tilt angle is about twice the tilt angle ⁇ is 2 ⁇ -2 ⁇ -5. The case where it changes.
- the angle at which the molecular direction of the ferroelectric liquid crystal changes in parallel with the first alignment treatment substrate surface can be measured with 7 fires.
- the liquid crystal molecules have a predetermined angle with the polarization axis, so that the polarized light transmitted through one polarizing plate passes through the other polarizing plate and becomes bright.
- the liquid crystal display element is rotated to the heel state.
- the angle at which the liquid crystal display element is rotated is measured.
- the angle by which the liquid crystal display element is rotated is the angle at which the molecular direction of the ferroelectric liquid crystal changes in parallel to the first alignment processing substrate surface.
- a ferroelectric liquid crystal for example, half-V shaped switching (hereinafter referred to as HV character), in which liquid crystal molecules operate only when a positive or negative voltage as shown in FIG. 12 is applied.
- HV character half-V shaped switching
- Ferroelectric liquid crystal exhibiting characteristics is used.
- the aperture time as a black and white shutter can be made sufficiently long, which makes it possible to display each color that is temporally switched brighter. Therefore, a bright color liquid crystal display device can be realized.
- the “HV-shaped switching characteristics” refers to electro-optical characteristics in which the light transmittance with respect to the applied voltage is asymmetric.
- the phase series of the ferroelectric liquid crystal is not particularly limited as long as it exhibits a chiral smetatic C phase (SmC *).
- the phase sequence changes during the cooling process from nematic phase (N) to cholesteric phase (Ch) to chiral smetatic phase C (SmC *), but nematic phase (N) to force illus phase.
- Phase change with tic C phase (SmC *), Nematic phase (N) —Smetatic A phase (SmA) —Chiral phase with chiral smetatic C phase (SmC *), Nematic phase (N) —Cholesteric Phase (Ch) —Smectic A phase (SmA) —Chiral smectic C phase (SmC *) phase change and the like.
- a ferroelectric liquid crystal having a phase sequence passing through an SmA phase as illustrated in the lower part of FIG. 13 is used in order to compensate for the volume change by reducing the layer spacing of the smectic layer during the phase change process.
- the smectic layer has a curved chevron structure, and domains with different major axis directions of liquid crystal molecules are formed depending on the bending direction, and alignment defects such as zigzag defects and hairpin defects are likely to occur at the interface.
- a ferroelectric liquid crystal having a phase sequence that does not go through the SmA phase as illustrated in the upper part of FIG. 13 is likely to generate two regions (double domains) having different layer normal directions.
- the alignment of the ferroelectric liquid crystal without causing such alignment defects can be mono-stabilized.
- Such a ferroelectric liquid crystal can be selected from various commonly known liquid crystal materials according to required characteristics.
- a liquid crystal material that exhibits an SmC * phase from the Ch phase without passing through the SmA phase is suitable for exhibiting HV-shaped switching characteristics.
- Specific examples include “R2301” manufactured by AZ Electronic Materials.
- the Ch phase force also expresses the SmC * phase through the SmA phase.
- a single liquid crystal material exhibiting an SmC * phase can be used as a force S, a non-liquid crystal liquid (hereinafter sometimes referred to as a host liquid crystal) that is low in viscosity and easily exhibits an SmC phase.
- a host liquid crystal a non-liquid crystal liquid
- the liquid crystal material showing the above phase sequence has a low viscosity and a faster response. This is preferable because it can be realized.
- the host liquid crystal is preferably a material exhibiting an SmC phase in a wide temperature range, and is not particularly limited as long as it is generally known as a host liquid crystal of a ferroelectric liquid crystal. I can do it.
- Ra and Rb are each a linear or branched alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkanoyloxy group or an alkoxycarbonyloxy group
- QQ 2 and Q 3 are each 1 , 4 phenylene group, 1,4-cyclohexylene group, pyridine 2,5 dinole group, pyrazine 2,5 dinole group, pyridazine 3,6 diyl group, 1,3 dioxane 2,5 diyl group
- These groups may have a substituent such as a halogen atom, a hydroxyl group, or a cyan group.
- X 1 and Y 1 are each COO——OCO——CH 2 O——OCH—CH CH C ⁇ C—or a single bond
- M is 0 or 1.
- the above compounds can be used alone or in combination of two or more.
- the optically active substance added to the host liquid crystal is not particularly limited as long as it is a material having an ability to induce an appropriate spiral pitch with a large spontaneous polarization, and generally a liquid crystal composition exhibiting an S mC phase. What is known as a material added to a thing can be used. In particular, a material that can induce large spontaneous polarization with a small addition amount is preferable. Examples of such an optically active substance include the following general formula: Rc Q 1 Za Q 2 Zb Q 3 Zc— Rd
- Rc is a linear or branched alkyl group optionally having an asymmetric carbon atom, An alkoxy group, an alkoxycarbonyl group, an alkanoyloxy group or an alkoxycarbonyloxy group, wherein Rd is a linear or branched alkyl group having an asymmetric carbon atom, an alkoxy group, an alkoxycarbonyl group, an alkanoyl group; Roxy and alkoxycarbonyloxy groups, and Rc and Rd may be substituted with a halogen atom, a cyano group or a hydroxyl group. ) Can be used.
- the above compounds may be used alone or in combination of two or more.
- ferroelectric liquid crystal that passes through the SmA phase
- ferroelectric liquid crystal that passes through the SmA phase
- ferroelectric liquid crystal that passes through the SmA phase
- the transmittance depends on the tilt angle of the liquid crystal molecules when a voltage is applied.
- the liquid crystal molecules are tilted on the cone. Therefore, for example, as shown in FIG. 12, the tilt angle of the liquid crystal molecules changes according to the magnitude of the applied voltage, and the transmittance changes. At this time, the transmittance is maximized when the tilt angle force is 5 ° from the monostable state of the liquid crystal molecules.
- the tilt angle from the monostable state of the liquid crystal molecules can be 45 ° when a voltage is applied so that the second electrode layer becomes a negative electrode during actual driving. It is preferable to use a ferroelectric liquid crystal!
- the maximum tilt angle from the monostable state of the liquid crystal molecules as shown in FIG. when a voltage is applied so that the second electrode layer is a negative electrode, the inclination angle of the liquid crystal molecules from the monostable state can be set to 45 °.
- the direction of liquid crystal molecules does not change approximately twice the tilt angle! /.
- the ferroelectric liquid crystal is sandwiched between the first alignment film and the second alignment film. This constitutes a liquid crystal layer.
- the liquid crystal layer may contain a compound having an arbitrary function depending on the function required for the liquid crystal display element.
- a compound having an arbitrary function include a polymerized polymerizable monomer.
- the polymerizable monomer used in the polymerization product of the polymerizable monomer is not particularly limited as long as it is a compound that generates a polymer by a polymerization reaction, and is a thermosetting resin monomer that generates a polymerization reaction by heat treatment. And actinic radiation curable resin monomers that undergo a polymerization reaction upon irradiation with actinic radiation. Among these, it is preferable to use an actinic radiation curable resin monomer.
- a thermosetting resin monomer it is necessary to perform a heating process in order to cause a polymerization reaction. Therefore, the regular arrangement of the ferroelectric liquid crystal is impaired by such a heating process, There is a risk of inducing a phase transition.
- an actinic radiation curable resin monomer when an actinic radiation curable resin monomer is used, the alignment of the ferroelectric liquid crystal is less likely to be harmed by such a polymerization reaction.
- Examples of the actinic radiation curable resin monomer include an electron beam curable resin monomer that undergoes a polymerization reaction upon irradiation with an electron beam, and a photocurable resin monomer that undergoes a polymerization reaction upon irradiation with light. Among them, it is preferable to use a photocurable resin monomer.
- the photo-curable resin monomer is not particularly limited as long as it causes a polymerization reaction when irradiated with light having a wavelength in the range of 150 nm to 500 nm.
- the polymerizable functional group possessed by the UV curable resin monomer is not particularly limited as long as it causes a polymerization reaction by UV irradiation in the above wavelength region.
- an ultraviolet curable resin monomer having an acrylate group may be used.
- the ultraviolet curable resin monomer may be a monofunctional monomer having one polymerizable functional group in one molecule, or has two or more polymerizable functional groups in one molecule. It may be a polyfunctional monomer. Among these, it is preferable to use a polyfunctional monomer.
- a polyfunctional monomer By using a polyfunctional monomer, a stronger polymer network can be formed, so that the intermolecular force and the polymer network at the alignment film interface can be strengthened. Thereby, the disorder of the alignment of the ferroelectric liquid crystal due to the temperature change can be suppressed.
- bifunctional monomers having polymerizable functional groups at both ends of the molecule are preferably used.
- polymerizable functional groups at both ends of the molecule it is possible to form a polymer network with a wide distance between polymers, and to prevent a decrease in the driving voltage of the ferroelectric liquid crystal due to the inclusion of a polymerizable monomer polymer. Because it can.
- the ultraviolet curable resin monomers it is preferable to use an ultraviolet curable liquid crystal monomer that exhibits liquid crystallinity.
- the reason why such an ultraviolet curable liquid crystal monomer is preferred is as follows. That is, since the ultraviolet curable liquid crystal monomer exhibits liquid crystallinity, it can be regularly arranged by the alignment regulating force of the alignment film. For this reason, the ultraviolet curable liquid crystal monomer can be fixed while maintaining a regular alignment state by causing a polymerization reaction after regularly arranging the ultraviolet curable liquid crystal monomer. Due to the presence of the polymer having such a regular alignment state, the alignment stability of the ferroelectric liquid crystal can be improved, and excellent heat resistance and impact resistance can be obtained.
- the liquid crystal phase exhibited by the ultraviolet curable liquid crystal monomer is not particularly limited.
- the N phase, the SmA phase, and the SmC phase can be cited.
- Examples of the ultraviolet curable liquid crystal monomer used in the present invention include compounds represented by the following formulas (1) to (3).
- A, B, D, E and F represent benzene, cyclohexane or pyrimidine, which may have a substituent such as halogen.
- a and B, or D and E may be bonded via a linking group such as an acetylene group, a methylene group, or an ester group.
- M 1 and M 2 may be any of a hydrogen atom, an alkyl group having 3 to 9 carbon atoms, an alkoxycarbonyl group having 3 to 9 carbon atoms, or a cyan group.
- the attaroyloxy group at the end of the molecular chain and A or D may be bonded via a bonding group such as an alkylene group having 3 to 6 carbon atoms.
- Y is hydrogen, alkyl having 1 to 20 carbons, anorekeninole having 1 to 20 carbons, alkyloxy having 1 to 20 carbons, alkyl having 1 to 20 carbons Oxycarbinole, honoreminore, gl ⁇ 20 (anorequinole ⁇ 7noreboninole, gl ⁇ 20 (anorequinole ⁇ 7norebonyloxy, halogen, cyano or nitro.
- H 2 C CHCOO- -COOC5HH
- the polymerizable monomers may be used alone or in combination of two or more.
- an ultraviolet curable liquid crystal monomer represented by the above formula and another ultraviolet curable resin monomer can be used.
- the polymer of the polymerizable monomer is a main chain liquid crystal type in which the main chain exhibits liquid crystallinity by having an atomic group exhibiting liquid crystallinity in the main chain. Even if it is a polymer, it may be a side chain liquid crystal type polymer in which the side chain exhibits liquid crystallinity by having an atomic group exhibiting liquid crystallinity in the side chain! /. Of these, the polymer of the polymerizable monomer is preferably a side chain liquid crystal polymer.
- the amount of the polymerized polymerizable monomer in the liquid crystal layer depends on the alignment of the ferroelectric liquid crystal. Although it is not particularly limited as long as it is within a range in which the qualitative property can be made to a desired level, it is usually more preferable that the range of 0.5% to 30% by mass in the liquid crystal layer is more preferable, and 1% to 20% by mass. More preferably, it is in the range of 1% by mass to 10% by mass. This is because if it exceeds the above range, the drive voltage may increase or the response speed may decrease. Further, if the amount is less than the above range, the alignment stability of the ferroelectric liquid crystal becomes insufficient, and the heat resistance of the liquid crystal display element may impair the impact resistance.
- the amount of the polymer of the polymerizable monomer in the liquid crystal layer is determined based on the weight of the polymer of the polymerizable monomer remaining after washing the monomolecular liquid crystal in the liquid crystal layer with a solvent. It can be calculated from the remaining amount obtained by measuring with a scale and the total mass of the liquid crystal layer.
- the ferroelectric liquid crystal since the ferroelectric liquid crystal exhibits monostability, it can be driven by an active matrix method using a thin film transistor (TFT), and voltage modulation is possible. A liquid crystal display element capable of more gradation control can be obtained.
- TFT thin film transistor
- the thickness of the liquid crystal layer is preferably in the range of 1.2 ⁇ 111-3. 0 m, more preferably 1.3 mm to 2.5 mm, and even more preferably 1.4. It is in the range of ⁇ m to 2.0 ⁇ m. This is because if the thickness of the liquid crystal layer is too thin, the contrast may be lowered. Conversely, if the thickness of the liquid crystal layer is too thick, the ferroelectric liquid crystal may be oriented.
- the thickness of the liquid crystal layer can be adjusted by a bead spacer, a columnar spacer, a partition wall or the like.
- a method for forming the liquid crystal layer a method generally used as a method for manufacturing a liquid crystal cell can be used.
- a vacuum injection method, a liquid crystal dropping method, or the like can be used.
- a ferroelectric liquid crystal that has been made isotropic liquid by heating to a liquid crystal cell that has been prepared using a first alignment treatment substrate and a second alignment treatment substrate in advance is utilized using the capillary effect.
- the liquid crystal layer is formed with a force S by pouring and sealing with an adhesive.
- liquid crystal dropping method for example, a heated ferroelectric liquid crystal is dropped on the second alignment film of the second alignment treatment substrate, a sealant is applied to the peripheral portion of the first alignment treatment substrate, and the first is applied under reduced pressure.
- the first crystallized substrate and the second crystallized substrate can be superposed and bonded via a sealant, so that a strong crystal layer can be formed.
- the first alignment treatment substrate used in the present invention includes a first base material, a first electrode layer formed on the first base material, and a first rubbing film formed on the first electrode layer. It has an alignment film.
- first alignment processing substrate each component in the first alignment processing substrate will be described.
- the first alignment film used in the present invention is formed on the first electrode layer and is a rubbing film.
- the material used for the rubbing film is not particularly limited as long as it can impart anisotropy to the alignment film by rubbing treatment.
- polyimide, polyamide, polyamideimide, polyether The ability to list imides, polybulal alcohol, polyurethane, etc. These may be used alone or in combination of two or more.
- the rubbing film preferably contains polyimide, and particularly preferably contains polyimide obtained by dehydrating and ring-closing (imidizing) polyamic acid.
- the polyamic acid can be synthesized by reacting a diamine compound with an acid dianhydride.
- diamine compounds used in the synthesis of polyamic acid include alicyclic diamines, carbocyclic aromatic diamines, heterocyclic diamines, aliphatic diamines, and aromatic diamines.
- Examples of the alicyclic diamine include 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 4,4'-diaminodicyclohexylenomethane, 4,4'-diamino-3,3, di. Examples thereof include methyldicyclohexane and isophorone diamine.
- carbocyclic aromatic diamines examples include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, diaminotoluene (specifically, 2,4 diaminotoluene), 1,4-diamino-2, and the like.
- heterocyclic diamines examples include 2,6 diaminopyridine, 2,4 diaminopyridin, 2,4 diamino-s triazine, 2,5 diaminodibenzofuran, 2,7 diamino force norlevazole, 3,6 diamino Examples thereof include carbazole, 3,7 diaminophenothiazine, 2,5 diamino-1,3,4, thiadiazole, 2,4 diamino-6 phenyl-1, s triazine and the like.
- Examples of the aliphatic diamine include 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,8-diaminooctane, 1,10 diaminodecane, 1,3-diamino-2,2 dimethylpropane, 1,6-diamino-2,5 dimethylhexane, 1,5 diamino-2,4 dimethylheptane, 1,7 diamino-3 methylheptane, 1,9-diamino-5 And methylnonane, 2,11-diaminododecane, 1,12-diaminooctadecane, 1,2-bis (3-aminopropoxy) ethane, and the like.
- aromatic diamine examples include, for example, a long-chain alkyl group represented by the following formula: Those having a monofluoro group are exemplified.
- Examples of the acid dianhydride used as a raw material when synthesizing the polyamic acid include aromatic acid dianhydrides and alicyclic acid dianhydrides.
- aromatic dianhydrides include pyromellitic dianhydride, 3, 3 ', 4, 4'-biphenyltetracarboxylic dianhydride, 2, 2', 3, 3 'biphenyl. Tetracarboxylic dianhydride, 2, 3, 3 ', 4-h, phenolete diol dianhydride, 3, 3', 4, 4 monobenzo, phenone tetracarboxylic acid Dianhydride, 2, 3, 3 ', 4' monobenzophenone tetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) Examples include sulfone dianhydride, 1, 2, 5, 6 naphthalene tetracarboxylic dianhydride, 2, 3, 6, 7 naphthalene tetracarboxylic dianhydride, and the like.
- Examples of alicyclic acid dianhydrides include 1, 2, 3, 4 cyclobutane tetracarboxylic dianhydride, 1, 2, 3, 4 cyclopentane tetracarboxylic dianhydride, 2, 3, 4, 5 Tetrahydrofurantetracarboxylic dianhydride, 1, 2, 4, 5 Cyclohexanetetracarboxylic dianhydride, 3, 4-dicarboxy 1-cyclohexyl succinic dianhydride, 3, 4-dicarboxy 1, 2, 3, 4 Tetrahydro-1 naphthalene succinic dianhydride, bicyclo [3, 3, 0] octane 2, 4, 6, 8 tetracarboxylic dianhydride and the like.
- These acid dianhydrides may be used alone or in combination of two or more. From the viewpoint of polymer transparency, it is preferable to use an alicyclic acid dianhydride.
- the polyamic acid is obtained by mixing the above-mentioned diamine compound and acid dianhydride in the presence of an organic solvent at 20 ° C to 150 ° C, preferably at 0 ° C to 80 ° C for 30 minutes to 30 minutes to It can be synthesized by reacting for 24 hours, preferably 1 hour to 10 hours.
- polyamic acid As a method of obtaining a polyimide film using polyamic acid, after polyamic acid is formed, it is heated or a catalyst is completely or partially dehydrated and closed (imidized), or polyamic acid is heated or A method of forming a film of this soluble polyimide after dehydrating and ring-closing (imidizing) all or partially with a catalyst to form a soluble polyimide can be mentioned.
- the soluble polyimide obtained by imidizing polyamic acid is excellent in storage stability, so a method of forming a film of soluble polyimide is preferred!
- the imidization reaction for converting polyamic acid into soluble polyimide includes thermal imidation in which the polyamic acid solution is heated as it is, and chemical imide in which a catalyst is added to the polyamic acid solution to perform imidization.
- thermal imidation in which the polyamic acid solution is heated as it is
- chemical imide in which a catalyst is added to the polyamic acid solution to perform imidization.
- polyamic acid is mixed in an organic solvent in an amount of 0.5 to 30 moles, preferably;! To 20 moles of a basic acid catalyst and 0.5 mole of amic acid group.
- the reaction is carried out at a temperature of 20 ° C. to 250 ° C., preferably 0 ° C. to 200 ° C. for 1 hour to 100 hours in the presence of ⁇ 50 mole times, preferably 1 to 30 mole times of acid anhydride. preferable. This is because when the amount of the base catalyst or acid anhydride is small, the reaction does not proceed sufficiently, and when it is too large, it is difficult to completely remove the reaction after the reaction is completed.
- Examples of the base catalyst used in the chemical imidation reaction include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine.
- pyridine is preferable because it has a basicity suitable for advancing the reaction.
- Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic anhydride, and the like. Of these, use of acetic anhydride is preferred because it facilitates purification after completion of the reaction.
- the imidization rate by chemical imidation can be controlled by adjusting the catalyst amount and the reaction temperature.
- the imidation ratio is preferably 0.1% to 99% of the total number of moles of polyamic acid, more preferably 5% to 90%, and more preferably 30% to 70%. Imidization rate is If it is too low, the storage stability will be poor, and if it is too high, the solubility will be poor and may precipitate.
- rubbing film As the rubbing film, "SE-5291” and “SE_7992” manufactured by Nissan Chemical Industries, Ltd. are preferably used.
- the above-mentioned material is applied and cured on the first electrode layer, and the obtained film is rubbed with a rubbing cloth in a certain direction to impart anisotropy to the alignment film. Use the force S.
- Examples of the method for applying the material include a roll coating method, a rod bar coating method, a slot die coating method, a wire bar coating method, an ink jet method, a flexographic printing method, and a screen printing method.
- the thickness of the rubbing film is set to about lnm to 1000nm, and preferably in the range of 50nm to lOOnm.
- the rubbing cloth for example, a material composed of fibers such as nylon resin, bull resin, rayon, cotton can be used. For example, by rotating a drum wrapped with such a rubbing cloth and bringing it into contact with the surface of the film using the above materials, fine grooves are formed in one direction on the film surface, and the alignment film is anisotropic. Is granted.
- the first electrode layer used in the present invention is not particularly limited as long as it is generally used as an electrode of a liquid crystal display element, but the first electrode layer and the second alignment treatment of the first alignment treatment substrate are not limited. It is preferable that at least one of the second electrode layers of the substrate is formed of a transparent conductor.
- the transparent conductor material include indium oxide, tin oxide, and indium tin oxide (ITO).
- one of the first alignment processed substrate and the second alignment processed substrate is formed of the transparent conductor described above.
- the gate electrode and the source electrode are arranged in a matrix, and the TFT element and the pixel electrode are provided in a portion surrounded by the gate electrode and the source electrode.
- the first electrode layer can be formed by chemical vapor deposition (CVD), sputtering, ion Examples thereof include a physical vapor deposition (PVD) method such as a plating method and a vacuum vapor deposition method.
- CVD chemical vapor deposition
- PVD physical vapor deposition
- the first substrate used in the present invention is not particularly limited as long as it is generally used as a substrate of a liquid crystal display element.
- a glass plate, a plastic plate and the like are preferable.
- a partition wall is formed on the first base material.
- the second alignment treatment substrate has a barrier rib on the second base material!
- the partition wall In the first alignment treatment substrate, no partition wall is formed on the first base material. That is, the partition wall may be formed on the second alignment processing substrate, or the partition wall may be formed on the first alignment processing substrate.
- the partition wall material As a material for the partition wall, a material generally used for a partition wall of a liquid crystal display element can be used.
- the partition wall material may be a resin, and among them, a photosensitive resin is preferably used. This is because the photosensitive resin is easy to pattern.
- a general patterning method is not particularly limited as long as the partition wall can be formed at a predetermined position.
- photolithography can be applied.
- One method, an inkjet method, a screen printing method, etc. are mentioned.
- a plurality of partition walls are formed, and it is preferable that the plurality of partition walls are regularly formed at predetermined positions. This is because, when a liquid crystal display device is manufactured by a liquid crystal dropping method, it may be difficult to accurately control the application amount of the ferroelectric liquid crystal if the formation positions of the plurality of partition walls are disordered. .
- the arrangement of the partition walls is not particularly limited, but it is preferable that the partition walls are formed in the non-pixel region. In the vicinity of the partition wall, V is likely to cause alignment failure of the ferroelectric liquid crystal, so that it has no effect on image display, and the ability to form a partition wall in the non-pixel region is preferable.
- the partition walls can be arranged on the gate electrode and the source electrode formed in a matrix shape.
- the force with which the plurality of partition walls are formed in a pattern for example, the partition walls are formed in a stripe shape It may be formed in a matrix shape or a frame shape.
- the partition wall is formed in a matrix shape, impact resistance can be improved.
- a frame-shaped partition wall is formed on the peripheral portion of the first base material to form the frame shape.
- the longitudinal direction of the stripe partition walls is the alignment treatment of the first alignment film.
- the partition is preferably formed so as to be substantially perpendicular to the direction.
- substantially vertical means that the angle formed by the longitudinal direction of the stripe-shaped partition walls and the alignment treatment direction of the first alignment film is in the range of 90 ° ⁇ 5 °. Is preferably in the range of 90 ° ⁇ 1 °. The angle can be measured by observing the alignment direction of the liquid crystal molecules (the alignment treatment direction of the first alignment film) and the longitudinal direction of the stripe-shaped partition using a polarizing microscope.
- the pitch of the partition walls is about 100 ⁇ m to about 10 mm, preferably about 200 ⁇ m to about 5 mm, more preferably about 1.0 mm to 5. Omm. This is because if the partition pitch is narrower than the above range, the display quality may be deteriorated due to poor alignment of the ferroelectric liquid crystal near the partition. On the other hand, if the partition pitch is wider than the above range, the force S varies depending on the size of the liquid crystal display element, the desired impact resistance cannot be obtained, or it is difficult to keep the cell gap constant. Because there is.
- the pitch of the partition means the distance from the center part of the adjacent partition wall to the center part.
- the width of the partition wall is set to about 1 ⁇ m to 20 ⁇ m, preferably in the range of 2 ⁇ m to 10 ⁇ m, more preferably in the range of 5 to 10.
- the width of the frame-shaped partition wall is the same as that of the ferroelectric liquid crystal and the uncured state. More specifically, the width should be 10 m to 3 mm, preferably 10 ⁇ m to 1 mm, and more preferably 10 ⁇ m to 500, as long as the width can prevent contact with the sealant. It is in the range of ⁇ m.
- the partition wall is also provided in the pixel region, and an effective pixel area may be narrowed and a good image display may not be obtained. This is because if it is narrower, it may be difficult to form partition walls.
- the height of the partition walls is usually set to be approximately the same as the cell gap.
- the pitch, width, and height of the partition walls can be measured by observing a cross section of the partition walls using a scanning electron microscope (SEM).
- the number of partition walls is not particularly limited as long as it is plural, and is appropriately selected depending on the size of the liquid crystal display element.
- the formation position is not particularly limited.
- the partition wall may be formed on the first base material layer. It suffices if a partition wall is formed on the surface.
- a columnar spacer is formed on the first base material!
- the columnar spacer is not formed on the first substrate in the first alignment substrate. That is, a columnar spacer may be formed on the first alignment substrate, or a column spacer may be formed on the second alignment substrate! /.
- the material of the columnar spacer it is possible to use a material generally used for a columnar spacer of a liquid crystal display element.
- a resin can be cited, and among these, a photosensitive resin is preferably used. This is because the photosensitive resin is easy to pattern.
- the method for forming the columnar spacer is not particularly limited as long as it is a method capable of forming the columnar spacer at a predetermined position.
- a photolithography method, an ink jet method, a screen printing method and the like can be mentioned.
- a plurality of columnar spacers are formed, and the plurality of columnar spacers are regularly formed at predetermined positions! /, And a force S is preferable, especially formed at regular intervals! /, I prefer to be .
- a liquid crystal display device is manufactured by the liquid crystal dropping method, if the formation positions of the plurality of columnar spacers are disordered, it may be difficult to accurately control the amount of ferroelectric liquid crystal applied. Because there is.
- the pitch of the columnar spacers can be about 100 Hm to 3 mm, preferably 200
- the pitch of the columnar spacer refers to the distance from the center to the center of adjacent columnar spacers.
- the diameter of the bottom surface is set to about 1 ⁇ m to about 100 ⁇ m, preferably 2 ⁇ m to 50 Within a range of ⁇ m, more preferably within a range of 5 m to 20 m. If the size of the columnar spacer is larger than the above range, the columnar spacer will be provided also in the pixel area, and the effective pixel area may be narrowed and a good image display may not be obtained. This is because if the size of the columnar spacer is smaller than the above range, it may be difficult to form the columnar spacer.
- the height of the columnar spacer is normally set to be approximately the same as the cell gap.
- the pitch, size, and height of the columnar spacer can be measured by observing the cross section of the partition using a scanning electron microscope (SEM).
- Examples of the columnar spacer shape include a cylindrical shape, a prismatic shape, a truncated cone shape, and the like.
- the arrangement of the columnar spacers is not particularly limited, but it is preferable that the columnar spacers are formed in the non-pixel region. This is because, in the vicinity of the columnar spacer, the alignment failure of the ferroelectric liquid crystal is likely to occur, and therefore it is preferable that the columnar spacer is formed in a non-pixel region that does not affect image display.
- the first alignment processing substrate is a TFT substrate
- columnar spacers can be arranged on the gate electrode and the source electrode formed in a matrix.
- the number of columnar spacers is not particularly limited as long as it is plural, and is appropriately selected depending on the size of the liquid crystal display element.
- the formation position is not particularly limited.
- the columnar spacer may be formed on the first base material.
- a columnar spacer is formed on the first electrode layer! /!
- a colored layer may be formed on the first base material!
- a colored layer is formed on the second base material on the second alignment substrate, no colored layer is formed on the first substrate in the first alignment substrate. That is, a colored layer may be formed on the first alignment treatment substrate, or a coloring layer may be formed on the second alignment treatment substrate.
- a color filter type liquid crystal display element capable of realizing color display by the colored layer can be obtained.
- a method for forming a colored layer a method for forming a colored layer in a general color filter can be used.
- a pigment dispersion method color resist method, etching method
- a printing method an inkjet method, etc.
- an inkjet method etc.
- the second alignment substrate used in the present invention is formed on the second base material, the second electrode layer formed on the second base material, and the second electrode layer, and causes a photodimerization reaction.
- a second alignment film that is a photo-alignment film using a photodimerization-type material that imparts anisotropy to the alignment film.
- the second base material, the second electrode layer, and other configurations are the same as the first base material, the first electrode layer, and other configurations of the first alignment treatment substrate, respectively. Description is omitted.
- the second alignment film on the second alignment processing substrate will be described.
- the second alignment film used in the present invention is formed on the second electrode layer, and a light distribution using a photodimerization-type material that imparts anisotropy to the alignment film by causing a photodimerization reaction. It is a counter membrane.
- the photodimerization reaction refers to a reaction in which the reaction site oriented in the polarization direction by light irradiation undergoes radical polymerization and two molecules are polymerized, and this reaction stabilizes the orientation in the polarization direction. Anisotropy can be imparted to the film.
- the photodimerization type material has the advantage that the range of material selection with high exposure sensitivity is wide.
- the photo-alignment process is a non-contact alignment process, it is useful in that it can control the alignment process without generating static electricity or dust.
- the photodimerization-type material used in the present invention is not particularly limited as long as it can impart anisotropy to the alignment film by a photodimerization reaction. It is preferable to include a photodimerization reactive compound having a dichroism having a group and different absorption depending on the polarization direction. By radically superimposing reaction sites oriented in the polarization direction, the orientation of the photodimerization reactive compound is stabilized, and it is possible to easily add anisotropic lifetime to the alignment film with a force S.
- the photodimerization-reactive compound having such characteristics includes a dimerization-reactivity having at least one reactive site selected from an ester of cinnamate ester, coumarin, quinoline, chalcone group and cinnamoyl group as a side chain. Mention may be made of polymers.
- the photodimerization reactive compound is preferably a dimerization reactive polymer containing any of cinnamate, coumarine or quinoline as a side chain. This is because anisotropy can be easily imparted to the alignment film by radical polymerization of ⁇ and ⁇ unsaturated ketone double bonds aligned in the polarization direction as reaction sites.
- the main chain of the dimerization reactive polymer is not particularly limited as long as it is generally known as a polymer main chain, but the reaction of the side chain such as an aromatic hydrocarbon group is not limited. V, which does not have a substituent containing a lot of ⁇ electrons that hinders the interaction between the sites, is preferable!
- the weight average molecular weight of the dimerization reactive polymer is not particularly limited, but is preferably in the range of 5,000 to 40,000, and in the range of 10,000 to 20,000. It is more preferable that The weight average molecular weight can be measured by a genorepermeation chromatography (GPC) method. If the weight average molecular weight of the dimerization reactive polymer is too small, it may not be possible to impart appropriate anisotropy to the alignment film. On the other hand, if it is too large, the viscosity of the coating solution at the time of forming the alignment film increases, and it may be difficult to form a uniform coating film.
- GPC genorepermeation chromatography
- dimerization reactive polymer examples include compounds represented by the following formula (4): [0171] [Chemical Formula 6]
- M 11 and M 1 each independently represent a monomer unit of a monopolymer or a copolymer.
- ethylene, acrylate, metatalylate, 2-chloro acrylate, attalinoleamide, methacrylolamide, 2-chloro acrylamide, styrene derivatives, maleic acid derivatives, siloxane and the like can be mentioned.
- M 12 may be acrylonitrile, methacrylonitrile, metatalylate, methyl methacrylate, hydroxyalkyl acrylate, or hydroxyalkyl methacrylate.
- D 1 and D 2 represent spacer units.
- R 1 is a group represented by — A 1 — (Z 1 — B 1 ) — Z 2
- R 2 is — A 1 — (Z 1 — B 1 ) — Z 3 —
- a group represented by zz A group represented by zz.
- a 1 and B 1 are each independently a covalent single bond, pyridin-1,2,5-dinole, pyrimidine-1,2,5-dinole, 1,4 cyclohexylene, 1,3 dioxane-1, 5 diyl, or 1, 4 phenylene which may have a substituent.
- Z 1 and Z 2 are each independently a single covalent bond, —CH—CH —CH 2 O
- E 1 represents a photodimerization reaction site, and examples thereof include a cinnamate ester, coumarin, quinoline, chalcone group, and cinnamoyl group.
- j and k are each independently 0 or 1;
- dimerization reactive polymer examples include compounds represented by the following formulas (5) to (8).
- dimerization-reactive polymer examples include compounds represented by the following formulas (9) to (12).
- photodimerization-reactive compound various photodimerization reaction sites and substituents can be selected from the compounds described above according to the required properties. Further, the photodimerization reactive compounds can be used alone or in combination of two or more.
- the photodimerization-type material does not interfere with the photoalignment of the alignment film! /, And contains an additive within the range! /, May be! /.
- the additive include a polymerization initiator and a polymerization inhibitor.
- the polymerization initiator or polymerization inhibitor may be appropriately selected from generally known compounds depending on the type of the photodimerization reactive compound.
- the addition amount of the polymerization initiator or the polymerization inhibitor is preferably in the range of 0.001% to 20% by mass with respect to the photodimerization reactive compound. The range of 0.1% to 5% by mass More preferably, it is within. This is because if the addition amount of the polymerization initiator or polymerization inhibitor is too small, the polymerization may not be started (prohibited), whereas if too large, the reaction may be inhibited.
- the wavelength region of the light that causes the photodimerization reaction of the photodimerization material is preferably within the range of ultraviolet light, that is, within the range of 10 nm to 400 nm. The range of 250 nm to 380 nm More preferably, it is within.
- the content of the photodimerization reactive compound in the coating solution for forming the second alignment film is preferably in the range of 0.05% by mass to 10% by mass. More preferably, it is in the range of 2% by mass. If the content is less than the above range, it will be difficult to impart appropriate anisotropy to the alignment film. Conversely, if the content is more than the above range, the viscosity of the coating liquid will increase, and the uniform coating film will be formed. This is because it becomes ⁇ to form.
- Examples of the application method of the second alignment film forming coating solution include spin coating, roll coating, rod bar coating, spray coating, air knife coating, slot die coating, wire bar coating, Use the inkjet method, flexographic printing method, screen printing method, etc.
- the thickness of the film obtained by applying the second alignment film forming coating solution is preferably in the range of lnm to;! OOOnm, more preferably in the range of 3 nm to; It is. This is because if the thickness of the film is thinner than the above range, sufficient optical alignment may not be obtained, and conversely, if the thickness of the film is thicker than the above range, it may be disadvantageous in cost.
- the obtained film can be imparted with anisotropy by causing a photodimerization reaction by irradiation with light with controlled polarization.
- the wavelength region of the light to be irradiated may be appropriately selected according to the constituent material of the alignment film to be used, but it is more preferable that it is in the ultraviolet light range, that is, in the range of 100 nm to 40 Onm. Is in the range of 250 nm to 380 nm.
- the polarization direction is not particularly limited as long as it can cause a photodimerization reaction.
- the liquid crystal display element of the present invention may have a polarizing plate as illustrated in FIG.
- the polarizing plate used in the present invention is not particularly limited as long as it transmits only a specific direction of the wave of light, and is generally used as a polarizing plate for liquid crystal display elements.
- the power to do S is not particularly limited as long as it transmits only a specific direction of the wave of light, and is generally used as a polarizing plate for liquid crystal display elements. The power to do S.
- the driving method of the liquid crystal display element of the present invention may be a color filter method in which color display is performed using a colored layer that is not limited to the field sequential method.
- an active matrix system using a thin film transistor is preferable. This is because by adopting an active matrix method using TFTs, the target pixel can be turned on and off reliably, enabling a high-quality display.
- the first alignment substrate may be a TFT substrate
- the second alignment substrate may be a common electrode substrate
- the first alignment substrate may be a common electrode substrate
- the second alignment substrate may be a TF.
- T may be used.
- the first alignment substrate strength STFT substrate and the second alignment substrate are preferably common electrode substrates!
- the switch of the TFT element 25 when the gate electrode 24x is set to a high potential of about 30 V, the switch of the TFT element 25 is turned on, and the signal voltage is applied to the strongly inductive liquid crystal by the source electrode 24y.
- the gate electrode 24x is set to a low potential of about 10V, the switch of the TFT element 25 is turned off.
- the switch-off state as illustrated in FIG. 10, a voltage is applied between the common electrode (second electrode layer) 14 and the gate electrode 24x so that the common electrode (second electrode layer) 14 side is positive.
- the ferroelectric liquid crystal does not operate, so that the pixel is in the dark state.
- the spontaneous polarization of the liquid crystal molecules tends to face the first alignment treatment substrate side due to the polar surface interaction. That is, in the switch-off state, as illustrated in FIG. 10, the spontaneous polarization Ps of the liquid crystal molecules 1 faces the TFT substrate (first alignment treatment substrate) 6 side. Therefore, the direction of spontaneous polarization is not affected by the voltage applied between the common electrode (second electrode layer) 14 and the gate electrode 24x.
- the spontaneous polarization is directed toward the common electrode substrate (second alignment substrate) when no voltage is applied, the effect of the voltage applied between the common electrode and the gate electrode in the switch-off state
- the direction of spontaneous polarization is reversed in the vicinity of the region where the gate electrode is provided. Then, in the vicinity of the region where the gate electrode is provided, the ferroelectric liquid crystal operates and light leakage occurs even though the switch is off.
- the direction of spontaneous polarization is not affected by the voltage applied between the common electrode and the gate electrode, so that no light leakage occurs. Therefore, in the present invention, light leakage near the gate electrode can be prevented by controlling the direction of spontaneous polarization and using the first alignment substrate as the TFT substrate and the second alignment substrate as the common electrode substrate. .
- the ferroelectric liquid crystal used in the present invention is such that when a voltage is applied so that the second electrode layer is a negative electrode, the molecular direction of the ferroelectric liquid crystal is the first alignment treatment substrate surface. In parallel, the tilt angle of the ferroelectric liquid crystal changes approximately twice.
- the ferroelectric liquid crystal when the voltage of the pixel electrode is relatively high with respect to the common electrode, a positive polarity voltage is applied, and when the pixel electrode voltage is relatively low, the negative polarity is applied.
- the ferroelectric liquid crystal when the first alignment processing substrate is a common electrode substrate and the second alignment processing substrate force STFT substrate, the ferroelectric liquid crystal has a pixel electrode voltage relatively lower than the common electrode. That is, when a negative polarity voltage is applied, the molecular direction of the ferroelectric liquid crystal changes approximately twice as much as the tilt angle of the ferroelectric liquid crystal in parallel with the surface of the first alignment substrate.
- the ferroelectric liquid crystal has a relatively high pixel electrode voltage relative to the common electrode.
- the molecular direction of the ferroelectric liquid crystal changes approximately twice the tilt angle of the ferroelectric liquid crystal in parallel with the surface of the first alignment processed substrate.
- the driving method of the liquid crystal display element of the present invention may be a segment method.
- the liquid crystal display element of the present invention can be produced by a method generally used as a method for producing a liquid crystal display element.
- a vacuum injection method, a liquid crystal dropping method, or the like can be used.
- a method for manufacturing a liquid crystal display element of the present invention a method for manufacturing an active matrix type liquid crystal display element using a TFT element will be described.
- a transparent conductive film is formed on the second base material by a vacuum deposition method to form a common electrode for the entire surface. Furthermore, a photo-dimerization-type material is applied on the common electrode, and a second alignment film is formed by applying a photo-alignment treatment to obtain a second alignment-treated substrate.
- a gate electrode and a source electrode are formed by patterning a conductive film in a matrix, a pixel electrode is formed by patterning a transparent conductive film, and a TFT element is installed.
- polyimide is applied on the gate electrode, the source electrode, the TFT element, and the pixel electrode, and a rubbing process is performed to form a first alignment film, thereby forming a first alignment processing substrate.
- beads are dispersed as a spacer on the first alignment film of the first alignment treatment substrate, and a sealant is applied to the periphery.
- the first alignment treatment substrate and the second alignment treatment substrate are opposed to each other so that the alignment treatment directions of the first alignment film and the second alignment film are substantially parallel, and are bonded and thermocompression bonded.
- the ferroelectric liquid crystal is injected in an isotropic liquid state using the capillary effect from the injection port, and the injection port is sealed with an ultraviolet curable resin or the like. After that, the strongly charged liquid crystal can be aligned by slow cooling.
- a transparent conductive film is formed on the second substrate by a vacuum vapor deposition method to form a common electrode on the entire surface.
- a partition wall is formed in a pattern on the common electrode layer by a photolithography method.
- a photodimerization-type material is applied onto the common electrode and the partition, and a photo-alignment process is performed to form a second alignment film, thereby forming a second alignment-processed substrate.
- a gate electrode and a source electrode are formed by patterning the conductive film in a matrix, and a pixel electrode is formed by patterning the transparent conductive film.
- polyimide is applied on the gate electrode, source electrode, TFT element, and pixel electrode, and a rubbing process is performed to form a first alignment film, thereby forming a first alignment process substrate.
- a ferroelectric liquid crystal is discharged in the state of an isotropic liquid onto the second alignment film of the second alignment processing substrate by an inkjet method.
- a sealant is applied around the first alignment processing substrate.
- the first alignment treatment substrate and the second alignment treatment substrate are heated to a temperature at which the ferroelectric liquid crystal exhibits a nematic phase or an isotropic phase, and the alignment of the first alignment film and the second alignment film is performed.
- the processing directions are made substantially parallel to each other, overlapped under reduced pressure, and bonded via a sealant. Thereafter, the encapsulated ferroelectric liquid crystal can be aligned by slowly cooling the liquid crystal cell to room temperature.
- the ferroelectric liquid crystal When aligning the ferroelectric liquid crystal, if a polymerizable monomer is added to the ferroelectric liquid crystal, the ferroelectric liquid crystal is aligned and then the polymerizable monomer is polymerized.
- the polymerization method of the polymerizable monomer is appropriately selected according to the type of the polymerizable monomer. For example, when an ultraviolet curable resin monomer is used as the polymerizable monomer, the polymerizable monomer is polymerized by ultraviolet irradiation. be able to.
- a voltage may or may not be applied to the liquid crystal layer composed of the ferroelectric liquid crystal, but in particular, no voltage is applied to the liquid crystal layer.
- V preferred to polymerize polymerizable monomers in the state.
- polarizing plates may be attached to the top and bottom of the liquid crystal cell obtained as described above.
- the present invention is not limited to the above embodiment.
- the above embodiment is merely an example, and has any configuration that is substantially the same as the technical idea described in the claims of the present invention and that exhibits the same operational effects. Are also included in the technical scope of the present invention.
- Two glass substrates on which ITO electrodes are formed are thoroughly cleaned, and a 2% by mass cyclopentanone solution of photodimerization material (Rolic technologies, trade name: ROP103) is rotated on one glass substrate. After spin coating at several 1500 rpm for 15 seconds and drying at 130 ° C for 15 minutes, alignment treatment was performed by irradiating with linearly polarized ultraviolet rays of about 10 mOm / cm 2 . Also, polyimide (Nissan Chemical Industries, trade name: SE-5291) was printed on the other substrate, and an alignment film was formed by rubbing.
- a 1.5 am bead spacer was sprayed on one substrate, and a sealant was applied to the other substrate with a seal dispenser. Next, both substrates were made to face each other so that their respective alignment treatment directions were parallel, and thermocompression bonding was carried out to produce an empty liquid crystal cell. [0203] Next, using a ferroelectric liquid crystal (trade name: R2301, manufactured by AZ Electronic Materials), a ferroelectric liquid crystal is attached to the upper part of the injection port, and an N-phase isotropic phase transition is performed using an oven. Injection was performed at a temperature 10 ° C to 20 ° C higher than the temperature, and the temperature was slowly returned to room temperature.
- a ferroelectric liquid crystal trade name: R2301, manufactured by AZ Electronic Materials
- the abundance ratio of double domains in the panel was approximately 83:
- the molecular direction of the ferroelectric liquid crystal is approximately 83% of the region.
- the tilt angle of the ferroelectric liquid crystal changed approximately twice in parallel to the substrate surface.
- Two glass substrates on which ITO electrodes are formed are thoroughly cleaned, and a 2% by mass cyclopentanone solution of photodimerization material (Rolic technologies, trade name: ROP103) is rotated on one glass substrate. After spin coating at several 1500 rpm for 15 seconds and drying at 130 ° C for 15 minutes, alignment treatment was performed by irradiating with linearly polarized ultraviolet rays of about 10 mOm / cm 2 . Further, polyimide (Nissan Chemical Industries, trade name: SE-7992) was printed on the other substrate, and an alignment film was formed by rubbing.
- a 1.5 am bead spacer was sprayed on one substrate, and a sealant was applied to the other substrate with a seal dispenser. Next, both substrates were made to face each other so that their respective alignment treatment directions were parallel, and thermocompression bonding was carried out to produce an empty liquid crystal cell.
- a ferroelectric liquid crystal (trade name: R2301, manufactured by AZ Electronic Materials), a ferroelectric liquid crystal is attached to the upper part of the injection port, and an N-phase isotropic phase transition is performed using an oven. Injection was performed at a temperature 10 ° C to 20 ° C higher than the temperature, and the temperature was slowly returned to room temperature.
- the abundance ratio of double domains in the panel is approximately 92:
- the molecular direction of the ferroelectric liquid crystal is approximately 92%.
- the tilt angle of the ferroelectric liquid crystal changed approximately twice in parallel to the substrate surface.
- a 1.5 m bead spacer was sprayed on one substrate, and a sealant was applied to the other substrate with a seal dispenser. Next, both substrates were made to face each other so that their respective alignment treatment directions were parallel, and thermocompression bonding was carried out to produce an empty liquid crystal cell.
- ferroelectric liquid crystal (trade name: R2301, manufactured by AZ Electronic Materials) was used.
- a ferroelectric liquid crystal was attached to the upper part of the injection port, and injection was performed at a temperature 10 ° C to 20 ° C higher than the N-phase isotropic phase transition temperature using an oven, and the temperature was slowly returned to room temperature.
- the abundance ratio of double domains in the panel is approximately 50:
- the molecular direction of the ferroelectric liquid crystal is parallel to the substrate surface in approximately 50% of the region. Changed about twice the tilt angle.
- a 1.5 m bead spacer was sprayed on one substrate, and a sealant was applied to the other substrate with a seal dispenser. Next, both substrates were made to face each other so that their respective alignment treatment directions were parallel, and thermocompression bonding was carried out to produce an empty liquid crystal cell.
- a ferroelectric liquid crystal (trade name: R2301, manufactured by AZ Electronic Materials) is used to attach a ferroelectric liquid crystal to the top of the injection port, and an oven is used to determine the N-phase isotropic phase transition temperature. Injection was performed at a temperature 10 ° C to 20 ° C higher, and the temperature was slowly returned to room temperature.
- the abundance ratio of double domains in the panel is approximately 50:
- the molecular direction of the ferroelectric liquid crystal is parallel to the substrate surface in approximately 50% of the region. Changed about twice the tilt angle.
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US12/515,591 US8130358B2 (en) | 2006-11-24 | 2007-11-19 | Liquid crystal display |
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CN103513468A (zh) * | 2012-06-14 | 2014-01-15 | 群康科技(深圳)有限公司 | 显示面板及其形成方法与显示*** |
US20150138496A1 (en) * | 2013-11-18 | 2015-05-21 | Nano And Advanced Materials Institute Limited | Polymer Stabilized Electrically Suppressed Helix Ferroelectric Liquid Crystal Cell |
TWI510846B (zh) * | 2013-12-16 | 2015-12-01 | Innolux Corp | 液晶顯示面板 |
CN104914603B (zh) * | 2014-03-14 | 2018-04-24 | 鸿富锦精密工业(深圳)有限公司 | 液晶面板的制造方法 |
CN104020608B (zh) * | 2014-05-06 | 2017-05-03 | 京东方科技集团股份有限公司 | 显示面板制造方法、显示面板和显示装置 |
US9798193B2 (en) | 2014-05-06 | 2017-10-24 | Boe Technology Group Co., Ltd. | Method for manufacturing a display panel, display panel and display device |
CN105785654A (zh) * | 2014-12-22 | 2016-07-20 | 业鑫科技顾问股份有限公司 | 液晶显示面板及其制作方法 |
CN106707593B (zh) * | 2015-11-17 | 2019-10-22 | 北京大学 | 一种聚合物分散双稳态近晶a相液晶薄膜及其制备方法 |
EP3822699B1 (en) * | 2016-07-29 | 2023-04-26 | Dai Nippon Printing Co., Ltd. | Vehicle with light control film attached to its sunroof |
CN111427197A (zh) * | 2020-04-30 | 2020-07-17 | 成都中电熊猫显示科技有限公司 | 显示面板及其配向方法、显示装置 |
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2007
- 2007-11-19 WO PCT/JP2007/072353 patent/WO2008062744A1/ja active Application Filing
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US8130358B2 (en) | 2012-03-06 |
CN101542373B (zh) | 2011-07-27 |
US20100053525A1 (en) | 2010-03-04 |
KR101160734B1 (ko) | 2012-06-28 |
JP5076458B2 (ja) | 2012-11-21 |
JP2008129529A (ja) | 2008-06-05 |
KR20090083944A (ko) | 2009-08-04 |
CN101542373A (zh) | 2009-09-23 |
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