KR20120059402A - Method for manufacturing liquid crystal display device - Google Patents

Abstract

The present invention provides a liquid crystal display device in which a blue phase can be stably expressed.
The liquid crystal layer containing the liquid crystal composition is sandwiched and the first substrate and the second substrate are fixed by a seal material, the alignment state of the liquid crystal layer is isotropic by heat treatment, and the liquid crystal layer is light irradiated to stabilize the polymer of the liquid crystal layer. While the treatment is performed, the alignment state of the liquid crystal layer is phase-shifted from isotropic to blue during light irradiation. Thereby, the liquid crystal display device which suppressed the defect (orientation defect) which shows the orientation state other than a blue phase is produced.

Description

Production method of liquid crystal display {METHOD FOR MANUFACTURING LIQUID CRYSTAL DISPLAY DEVICE}

A liquid crystal display device and its manufacturing method are related.

In display devices (so-called flat panel displays) that are designed to be thin and lightweight, a liquid crystal display device having a liquid crystal element, a light emitting device having a self-luminous element, a field emission display (FED) and the like have been developed in competition. .

In a liquid crystal display device, the speed | rate of the response speed of liquid crystal molecules is calculated | required. Among various liquid crystal display modes, a liquid crystal mode capable of high-speed response may include a FLC (Ferroelectric Liquid Crystal) mode, an OCB (Optical Compensated Bend) mode, and a mode using a liquid crystal exhibiting a blue phase.

The blue phase is a liquid crystal phase expressed between a chiral nematic phase having a relatively short spiral pitch and an isotropic phase, and has a very high response speed. Moreover, when using a blue phase, since the orientation film is unnecessary and the viewing angle is wide, the research for practical use is advanced. However, since the blue phase is expressed only in the temperature range of only 1 ° C to 3 ° C between the cholesteric phase and the isotropic phase, it is a problem to precisely control the temperature of the device.

In order to solve this problem, it is proposed to extend the temperature range where the blue phase is expressed by performing a polymer stabilization treatment (see Patent Document 1, for example).

International Publication No. 2005/090520

A polymer stabilization process is a process which irradiates light to the liquid crystal composition containing photocurable resin, and irradiates light, superposes | polymerizes photocurable resin and stabilizes a liquid crystal layer. However, it is difficult to uniformly polymerize the photocurable resin in the substrate plane. If the polymerization of the polymer is nonuniform, the alignment state in the liquid crystal layer also becomes nonuniform, so that the blue phase is not stably expressed.

One object of one embodiment of the present invention is to provide a method for producing a liquid crystal display device in which a blue phase can be stably expressed.

One aspect of the disclosed invention is to irradiate a liquid crystal composition at a temperature exhibiting an isotropic phase when producing a liquid crystal display device having a liquid crystal layer in which a blue phase can be expressed to polymerize the photocurable resin contained in the liquid crystal composition and to further irradiate the light. It is to suppress the defect (henceforth orientation defect) which shows the orientation state other than a blue phase by phase-shifting the orientation state of a liquid crystal layer from an isotropic phase to a blue phase during a process. More specifically, the following production methods are mentioned, for example.

In one embodiment of the present invention, a liquid crystal layer containing a liquid crystal composition is sandwiched, the first substrate and the second substrate are fixed by a sealing material, and the alignment state of the liquid crystal layer is isotropic by heat treatment, and the liquid crystal layer It irradiates into light and performs the polymer stabilization process of a liquid crystal layer, and is a manufacturing method of the liquid crystal display device which phase-transforms the orientation state of a liquid crystal layer from an isotropic phase to a blue phase during light irradiation.

In another embodiment of the present invention, a sealing material is formed on the first substrate in a frame shape, the liquid crystal composition is dropped in a mold formed of the sealing material, and a second substrate is bonded to the first substrate in a reduced pressure atmosphere to form a liquid crystal layer. Liquid crystal display in which the alignment state of the liquid crystal layer is isotropic by heat treatment, the light is irradiated to the liquid crystal layer to perform the polymer stabilization treatment of the liquid crystal layer, and the phase change of the alignment state of the liquid crystal layer from isotropic phase to blue phase during light irradiation. It is a manufacturing method of a device.

Another embodiment of the present invention is to form a seal member in a frame shape on a first substrate, temporarily harden the seal member by irradiating with light, and drop the liquid crystal composition into a mold formed of the temporarily cured seal member, and then, in a reduced pressure atmosphere, the first substrate. The second substrate is bonded to the substrate to form a liquid crystal layer, the alignment state of the liquid crystal layer is isotropic by heat treatment, the light is irradiated to the liquid crystal layer, and the curing of the seal material and the polymer stabilization treatment of the liquid crystal layer are performed. It is a manufacturing method of the liquid crystal display device which phase-transfers the orientation state of a liquid crystal layer from an isotropic phase to a blue phase during irradiation.

Another embodiment of the present invention is to form a seal member on a first substrate in a frame shape, to drop the liquid crystal composition into a mold formed of the seal member, and to temporarily cure the seal member by irradiating with light, and then to the first substrate under a reduced pressure atmosphere. The substrate is bonded to form a liquid crystal layer, the alignment state of the liquid crystal layer is isotropic by heat treatment, the light is irradiated to the liquid crystal layer to perform complete curing of the sealing material and polymer stabilization treatment of the liquid crystal layer, and liquid crystal during light irradiation. It is a manufacturing method of the liquid crystal display device which phase-changes the orientation state of a layer from an isotropic phase to a blue phase.

In the manufacturing method of the said liquid crystal display device, the composition containing a liquid crystal material, a chiral agent, a photocurable resin, and a photoinitiator can be used as a liquid crystal composition.

In one embodiment of the disclosed invention, a material showing a blue phase in a certain temperature range is used as the liquid crystal composition. The material exhibiting a blue phase is capable of high-speed response, thereby enabling high performance of the liquid crystal display device.

In addition, the liquid crystal display device in this specification refers to an image display device, a display device, or a light source (including an illumination device). In addition, a connector such as a flexible printed circuit (FPC), a tape automated bonding (TAB) tape, a module equipped with a tape carrier package (TCP), a module having a printed wiring board formed at the end of the TAB tape or the TCP, or a display element All modules in which ICs (integrated circuits) are directly mounted on a formed substrate by a chip on glass (COG) method are also included in the liquid crystal display.

According to one embodiment of the disclosed invention, a highly reliable liquid crystal display device in which a blue phase can be stably expressed can be manufactured. Moreover, the yield at the time of preparation of a liquid crystal display device can be improved.

1A to 1E illustrate an example of a manufacturing process of a liquid crystal display device.
2 is a model diagram of an alignment state of a liquid crystal composition.
3A, 3B, and 3C are diagrams showing an example of the configuration of a liquid crystal display device.
4 is a diagram showing a configuration example of a liquid crystal display device.
5A and 5B show an example of a usage form of a liquid crystal display device.
6A to 6F are diagrams showing an example of usage forms of the liquid crystal display device.
7A to 7C are external photographs of the liquid crystal display device produced in the embodiment.

EMBODIMENT OF THE INVENTION Below, embodiment of this invention is described in detail using drawing. However, it is apparent to those skilled in the art that the present invention is not limited to the contents of the embodiments described below, and that the form and details can be variously changed without departing from the spirit of the invention. Therefore, this invention is not limited to description content of embodiment described below. In addition, the structure which concerns on a different embodiment and an Example can be implemented in combination suitably. In addition, the same code | symbol is used for the same part and the part which has the same function in the structure of the invention demonstrated below, and the repeated description is abbreviate | omitted.

(Embodiment 1)

In this embodiment, an example of the manufacturing method of a liquid crystal display device is demonstrated with reference to drawings. In addition, in this embodiment, although the method of manufacturing one liquid crystal display device using a pair of board | substrate is described, this embodiment is not limited to this, A some liquid crystal display device is produced using a large sized board | substrate (so-called Multi-sided acquisition).

First, the first substrate 100 is prepared, and the seal member 102 is formed on the first substrate 100 (see FIG. 1A).

As the first substrate 100, glass substrates (also called "alkali glass substrates") used in the electronics industry, such as aluminosilicate glass, alumino borosilicate glass, barium borosilicate glass, quartz substrates, ceramic substrates, plastic substrates, SOI substrates and the like can be used. Elements such as transistors constituting pixels and the like of the liquid crystal display device may be provided on these substrates.

It is preferable to use photocurable resin, thermosetting resin, photocurable, thermosetting resin, etc. as the sealing material 102. As shown in FIG. For example, an acrylic resin, an epoxy resin, an acrylate (urethane acrylate) resin, an amine resin, a resin obtained by mixing an acrylic resin and an epoxy resin can be used. Moreover, you may contain a light (typically ultraviolet-ray) polymerization initiator, a thermosetting agent, a filler, and a coupling agent. In addition, photocurable resin means resin hardened | cured by light irradiation, and thermosetting resin means resin hardened | cured by heat processing. In addition, photocurable and thermosetting resin refer to resin which is temporarily hardened by light irradiation and is fully hardened by heat-processing after that.

The seal member 102 may be formed in a frame shape (closed ring shape). The case where the sealing material 102 is formed in rectangle in FIG. 1A is shown. However, the shape of the seal member 102 is not limited to a rectangle, and may be formed in a circular shape, an ellipse shape, or a polygonal shape other than a rectangle.

Next, the liquid crystal composition 106 is dripped on the 1st board | substrate 100 and in the inside (inside of a frame) of the sealing material 102 (refer FIG. 1B).

As the liquid crystal composition 106, a liquid crystal composition showing a blue phase can be used. The liquid crystal composition showing a blue phase contains a liquid crystal material, a chiral agent, a photocurable resin, and a photopolymerization initiator. In addition, the liquid crystal composition which shows a blue phase does not need to show a blue phase at the time of dripping on the 1st board | substrate 100, What is necessary is just a liquid crystal composition which shows a blue phase at a certain temperature by temperature control.

As the liquid crystal material, a thermotropic liquid crystal, a low molecular liquid crystal, a polymer liquid crystal, a ferroelectric liquid crystal, an antiferroelectric liquid crystal, or the like can be used.

A chiral agent is used in order to induce the twist of a liquid crystal material, orient a liquid crystal material in a spiral structure, and to express a blue phase. The chiral agent is a compound having an asymmetric center, and a compound having good compatibility with the liquid crystal composition and having a strong twisting power is used. In addition, the chiral agent is an optically active agent, the higher the optical purity is, the more preferable is 99% or more.

The photocurable resin may be a monofunctional monomer such as acrylate or methacrylate, or may be a polyfunctional monomer such as diacrylate, triacrylate, dimethacrylate, or trimethacrylate. It may be mixed. Moreover, a liquid crystalline thing may be sufficient, a non-liquid crystalline thing may be sufficient, and these may be mixed. What is necessary is just to select resin which superposes | polymerizes with the light of the wavelength with which the photoinitiator used for a liquid crystal composition reacts, and photocurable resin can use ultraviolet curable resin typically.

The photoinitiator may be a radical polymerization initiator which generates a radical by light irradiation, an acid generator which generates an acid, or a base generator which generates a base.

In addition, the case where the droplet of the liquid crystal composition 106 is dripped in the inside of the sealing material 102 is shown to FIG. 1B. In addition, the manufacturing method of the liquid crystal display device described in this embodiment is not limited to this, You may drip several drops to the required location inside the seal material 102, and what is necessary is just to drop the required amount of liquid crystal composition 106. .

Next, the second substrate 108 is bonded to the first substrate 100 (see FIG. 1C). The first substrate 100 and the second substrate 108 are fixed to the seal member 102.

The liquid crystal composition 106 dropped by the 1st board | substrate 100 and the 2nd board | substrate 108 is bonded, spreads in the frame of the sealing material 102, and the liquid crystal layer 110 is formed. In addition, since the liquid crystal composition 106 contains a chiral agent, the viscosity is high. Therefore, when the first substrate 100 and the second substrate 108 are bonded to each other, the liquid crystal layer 110 may not spread to the entire surface of the seal member 102 (does not contact the seal member 102). have.

As the second substrate 108, the same material as that of the first substrate 100 can be used.

It is preferable to perform bonding of the 1st board | substrate 100 and the 2nd board | substrate 108 in a reduced pressure atmosphere. This is because the inside of the frame of the sealing material 102 can be kept in a reduced pressure state and finally the liquid crystal composition 106 can be spread to an area in contact with the sealing material 102 even when the air is opened after the bonding by bonding in a reduced pressure atmosphere. .

In addition, after forming the sealing material 102 on the 1st board | substrate 100 (after the process of FIG. 1A), or after joining the 1st board | substrate 100 and the 2nd board | substrate 108 (after the process of FIG. 1C), light The seal member 102 may be temporarily cured by irradiation or heat treatment. Temporary hardening of the sealing material 102 can prevent position shift of the board | substrate by heat deformation in a subsequent heat processing process. In addition, since the adhesion between the seal member 102 and the substrate (the first substrate 100 and the second substrate 108) is improved, the liquid crystal composition 106 can be prevented from leaking outside (outside the frame) beyond the seal member. . Also, by temporarily curing the seal member 102 before dropping the liquid crystal composition 106, impurities are mixed into the liquid crystal composition 106 from the seal member 102 when the liquid crystal composition 106 is in contact with the seal member 102. Can be reduced.

Next, a heat treatment is performed on the liquid crystal layer 110 sandwiched between the first substrate 100 and the second substrate 108 to form a liquid crystal layer 112 showing an isotropic phase by the heat treatment (FIG. 1D). Reference). What is necessary is just to make the liquid crystal composition which comprises a liquid crystal layer more than the temperature which an isotropic phase can express, and the heat processing means can use the stage which has a heat source, such as a heater, for example, and arrange | positions a board | substrate thereon The heat treatment may be performed. In addition, although the dropping trace may be formed in the 1st board | substrate 100 when dripping a liquid crystal composition, when the liquid crystal composition is made into 10 degreeC or more higher than the phase transition temperature of a blue phase and an isotropic phase, the said dripping trace can be lost, It is preferable because the alignment disturbance of the liquid crystal layer due to traces of dropping can be prevented. In addition, the phase transition temperature of a blue phase and an isotropic phase means the temperature which phase-transforms from a blue phase to an isotropic phase at the time of temperature rising, or the temperature which phase-transforms from an isotropic phase to a blue phase at the time of temperature rising.

Thereafter, a polymer stabilization treatment is performed on the liquid crystal layer 112 showing an isotropic phase to polymerize the photocurable resin contained in the liquid crystal composition 106, and a blue phase is expressed in the liquid crystal composition 106. This forms the liquid crystal layer 114 which shows a blue phase (refer FIG. 1E).

The polymer stabilization treatment can be performed by irradiating light of a wavelength at which the photocurable resin and the photopolymerization initiator react with a liquid crystal composition containing a liquid crystal material, a chiral agent, a photocurable resin, and a photopolymerization initiator.

Before the light irradiation (before the polymer stabilization treatment), the photocurable resin contained in the liquid crystal composition is in a monomer state, and the photocurable resin polymerizes by light irradiation and gradually changes to a polymer state. The phase transition temperatures of the blue phase and the isotropic phase are affected by the photocurable resin in the monomer state in addition to the liquid crystal material in the liquid crystal composition, while the photocurable resin in the polymer state is less likely to affect the temperature. Therefore, as the ratio of the photocurable resin in the polymer state contained in the liquid crystal composition is increased by light irradiation, the phase transition temperatures of the blue phase and the isotropic phase linearly rise (or decrease). Generally, the phase transition temperature of a blue phase and an isotropic phase falls by containing the photocurable resin of a monomer state.

The liquid crystal composition used by this embodiment is adjusted so that the phase transition temperature of a blue phase and an isotropic phase may fall compared with the case where only a liquid crystal material and a chiral agent are contained by containing the photocurable resin of a monomer state. Therefore, the phase transition temperature of a blue phase and an isotropic phase of a liquid crystal composition increases by increasing light-curable resin of a polymer state by light irradiation.

The model figure of the orientation state in the liquid crystal composition used for this embodiment in FIG. 2 is shown. In FIG. 2, the horizontal axis represents light irradiation time to the liquid crystal composition, and the vertical axis represents temperature of the liquid crystal composition. In addition, the broken line 200 shows the phase transition temperature of a blue phase and an isotropic phase. In addition, in FIG. 2, Ta represents the phase transition temperature of a blue phase and an isotropic phase in a liquid crystal composition before light irradiation.

The manufacturing method of the liquid crystal display device described in this embodiment is irradiated with light to a liquid crystal layer 112 showing an isotropic phase, that is, a liquid crystal layer having a temperature higher than Ta, to perform polymer stabilization treatment, and to be blue on an isotropic phase during light irradiation treatment. Phase change to phase. As described above, the liquid crystal composition used in the present embodiment has a temperature Tb, for example, because the phase transition temperature of the blue phase and the isotropic phase of the liquid crystal composition is increased by increasing the photocurable resin in the polymer state by light irradiation. When light is irradiated to a liquid crystal layer for t1 time, as shown in FIG. 2, the phase transition temperature of the blue phase and isotropic phase shown by the broken line 200 also increases by light irradiation. Therefore, by maintaining the temperature of the liquid crystal layer at Tb and irradiating with light, the liquid crystal layer 114 showing a blue phase can be formed at the end of light irradiation (after t1 hours). Thus, according to the manufacturing method of the liquid crystal display device described in this embodiment, superposition | polymerization of photocurable resin and phase transition from an isotropic phase to a blue phase can be performed simultaneously (in the same process).

When the polymer stabilization process is started in the liquid crystal layer showing the blue phase, when the blue phase is expressed, an alignment defect is formed in the region during light irradiation because a region in which deformation such as stress is concentrated due to volume shrinkage due to phase transition is formed. It may occur. However, as described in this embodiment, the alignment defect is dispersed because the deformation due to volume shrinkage is dispersed throughout the entire surface of the substrate by simultaneously performing the expression of the blue phase and the polymer stabilization treatment (which may be referred to as polymerization of the photocurable resin). Can be suppressed.

In addition, when starting a polymer stabilization process to the liquid crystal layer which shows a blue phase, in order to orientate a liquid crystal layer again before performing a polymer stabilization process, it heats until an isotropic phase is expressed, and after that, a liquid crystal is carried out to the temperature which a blue phase expresses. Cool the layer slowly. Here, it is necessary to control temperature precisely in order to suppress an orientation defect when cooling a liquid crystal layer gradually. However, according to the manufacturing method of the liquid crystal display device described in this embodiment, since the polymer stabilization process can be performed to the liquid crystal composition heated until an isotropic phase is expressed without complicated temperature control, a process can be simplified and a yield Can improve. In addition, since it is possible to cool rapidly within the temperature range in which the isotropic phase is expressed after heating until the isotropic phase is expressed if necessary, the throughput of manufacturing the liquid crystal display device is also improved.

After the polymer stabilization treatment, the seal member 102 is cured. What is necessary is just to set hardening process suitably according to the material of a sealing material, For example, when using a thermosetting resin as the sealing material 102, the sealing material 102 is hardened by heat-processing. Or when using photocurable resin as the sealing material 102, the sealing material 102 is hardened by irradiating the light of the wavelength with which the said photocurable resin reacts. In the case where the seal member 102 is temporarily cured after the seal member 102 is formed on the first substrate 100 or after the first substrate 100 and the second substrate 108 are bonded together, By this, the seal member 102 can be completely cured.

In addition, when using photocurable resin as the sealing material 102, you may harden | cure (or completely harden | cure) the sealing material 102 simultaneously in the light irradiation process of a polymer stabilization process. In addition, when using thermosetting resin as the sealing material 102, you may harden (or completely harden) the sealing material 102 by the heat processing for expressing an isotropic phase. In such a case, the curing treatment step can be reduced, so that the manufacturing process can be simplified.

In addition, although not shown in figure, an optical film, such as a polarizing plate, a retardation plate, and an anti-reflective film, can be installed suitably in a liquid crystal display device. For example, circularly polarized light by a polarizing plate and a retardation plate may be used. In addition, a backlight, a side light, or the like may be used as the light source.

In the present specification, when the liquid crystal display device is a transmissive liquid crystal display device (or semi-transmissive liquid crystal display device) that transmits and displays light of a light source, it is necessary to transmit light at least in the pixel region. Therefore, all the thin films, such as an insulating film and a conductive film provided in the 1st board | substrate, the 2nd board | substrate, or the 1st board | substrate or the 2nd board | substrate which exist in the pixel area through which light transmits, shall transmit light to the light of the wavelength range of visible light. .

The electrode layer (called a pixel electrode layer, a common electrode layer, a counter electrode layer, etc.) for applying a voltage to the liquid crystal layer preferably has light transmittance, but a non-transmissive material such as a metal film may be used depending on the pattern of the electrode layer.

The electrode layer includes indium tin oxide (ITO), a conductive material in which zinc oxide (ZnO) is mixed with indium oxide, a conductive material in which silicon oxide (SiO ₂ ) is mixed with indium oxide, indium containing organic indium, organic tin, and tungsten oxide Oxide, indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, graphene or tungsten (W), molybdenum (Mo), zirconium (Zr), hafnium (Hf) ), Vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), cobalt (Co), nickel (Ni), titanium (Ti), platinum (Pt), aluminum (Al), copper (Cu) ), Metals such as silver (Ag), alloys thereof, or one or more kinds of metal nitrides thereof can be formed.

Moreover, it can form using the electroconductive composition containing a conductive polymer (also called a conductive polymer) as an electrode layer. The pixel electrode formed using the conductive composition has a sheet resistance of 10000 Ω / sq. Hereinafter, it is preferable that the light transmittance at wavelength 550nm is 70% or more. Moreover, it is preferable that the resistivity of the conductive polymer contained in a conductive composition is 0.1 ohm * cm or less.

As the conductive polymer, a so-called π-electron conjugated conductive polymer can be used. For example, polyaniline or derivatives thereof, polypyrrole or derivatives thereof, polythiophene or derivatives thereof, or a copolymer consisting of two or more of aniline, pyrrole and thiophene or derivatives thereof may be mentioned.

The liquid crystal display device of this embodiment can be manufactured through the above-mentioned process. The liquid crystal display device produced using the manufacturing method described in this embodiment is a highly reliable liquid crystal display device in which orientation defects can be suppressed and a blue phase can be stably expressed. Moreover, the yield at the time of manufacturing a liquid crystal display device can be improved by applying this embodiment.

In addition, this embodiment can be implemented in appropriate combination with the description content of another embodiment.

(Embodiment 2)

In this embodiment, an example of the liquid crystal display device produced by the said embodiment is demonstrated with reference to drawings.

3A and 3B illustrate a panel in which a transistor 4010, a transistor 4011, and a liquid crystal element 4013 formed on a first substrate 4001 are sealed with a sealing material 4005 between a second substrate 4006. It is a top view, and FIG. 3C is corresponded in sectional drawing cut along the line MN of FIG. 3A and FIG. 3B.

A seal member 4005 is provided to surround the pixel portion 4002 and the scan line driver circuit 4004 provided on the first substrate 4001. In addition, a second substrate 4006 is provided over the pixel portion 4002 and the scan line driver circuit 4004. The pixel portion 4002 and the scan line driver circuit 4004 are sealed together with the liquid crystal layer 4008 showing a blue phase by the first substrate 4001, the seal member 4005, and the second substrate 4006.

3A shows a signal line driver circuit 4003 formed of a single crystal semiconductor film or a polycrystalline semiconductor film on a substrate separately prepared in an area surrounded by the seal member 4005 on the first substrate 4001 and another area. 3B illustrates an example in which a portion of the signal line driver circuit is formed of a transistor using an oxide semiconductor on the first substrate 4001, and a signal line driver circuit 4003b is formed on the first substrate 4001 and is separately prepared. The signal line driver circuit 4003a formed of a single crystal semiconductor film or a polycrystalline semiconductor film is mounted thereon.

In addition, the connection method of the drive circuit formed separately is not specifically limited, A COG method, a wire bonding method, a TAB method, etc. can be used. 3A shows an example of mounting the signal line driver circuit 4003 by the COG method, and FIG. 3B shows an example of mounting the signal line driver circuit 4003a by the TAB method.

The pixel portion 4002 and the scan line driver circuit 4004 provided on the first substrate 4001 have a plurality of transistors, and the transistor 4010 and the scan line driver circuit 4004 included in the pixel portion 4002 in FIG. 3C. The transistor 4011 included in FIG. 1 is illustrated. An insulating layer 4020 and an insulating layer 4021 are formed over the transistor 4010 and the transistor 4011.

The transistor 4010 and the transistor 4011 are not particularly limited, and various transistors can be applied. As the channel layer of the transistor 4010 and the transistor 4011, a semiconductor such as silicon (amorphous silicon, microcrystalline silicon, or polysilicon) or an oxide semiconductor can be used.

In addition, a pixel electrode layer 4030 and a common electrode layer 4031 are provided on the first substrate 4001, and the pixel electrode layer 4030 is electrically connected to the transistor 4010. The liquid crystal element 4013 includes a pixel electrode layer 4030, a common electrode layer 4031, and a liquid crystal layer 4008.

In addition, in a liquid crystal display device having a liquid crystal layer 4008 exhibiting a blue phase, an electric field is generated substantially parallel to the substrate (ie, a direction parallel to the substrate) to move the liquid crystal molecules in a plane parallel to the substrate. ) Can be used. As such a method, the present embodiment describes a case where the electrode configuration used in the In Plane Switching (IPS) mode as shown in FIG. 3C is applied. In addition, the electrode configuration used in the FFS (Fringe Field Switching) mode is not limited to the IPS mode.

As the first substrate 4001 and the second substrate 4006, glass, plastic, or the like having transparency can be used. As the plastic, polyether sulfone (PES), polyimide, Fiberglass-Reinforced Plastics (FRP) plate, PVF (polyvinyl fluoride) film, polyester film, or acrylic resin film can be used. Moreover, the sheet | seat of the structure which sandwiched aluminum foil with the PVF film or the polyester film can also be used.

In addition, the columnar spacer 4035 provided to control the film thickness (cell gap) of the liquid crystal layer 4008 can be formed by selectively etching the insulating film. In addition, a spherical spacer may be used instead of the columnar spacer 4035.

In FIG. 3C, a light blocking layer 4034 is provided on the second substrate 4006 side to cover the transistor 4010 and the transistor 4011. By providing the light shielding layer 4034, the effect of transistor stabilization can be enhanced. This light shielding layer 4034 may be provided on the first substrate 4001 side. In this case, the photocurable resin contained in the liquid crystal composition on the light shielding layer 4034 can also be polymerized when light is irradiated from the second substrate 4006 to perform the polymer stabilization treatment.

When the light shielding layer 4034 is provided on the first substrate 4001 side, the light shielding layer 4034 may be covered with an insulating layer 4020 functioning as a protective film of the transistor, but is not particularly limited.

In addition, the protective film is for preventing the ingress of contaminant impurities such as organic matter, metal matter, water vapor and the like suspended in the air, and a dense film is preferable. When the protective film is formed by sputtering, a silicon oxide film, a silicon nitride film, a silicon oxynitride film, a silicon nitride oxide film, an aluminum oxide film, an aluminum nitride film, an aluminum oxynitride film, or an aluminum nitride oxide film is formed in a single layer or laminated. good.

In addition, after forming a protective film, you may heat-process a semiconductor layer at 300 degreeC-400 degreeC.

The pixel electrode layer 4030 and the common electrode layer 4031 are indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, and indium tin oxide ( ITO), an indium zinc oxide, an indium tin oxide added with silicon oxide, a conductive material having light transmittance, such as graphene, can be used.

In addition, it can be formed using a conductive composition containing a conductive polymer (also referred to as a conductive polymer) as the pixel electrode layer 4030 and the common electrode layer 4031.

In addition, various signals and potentials are supplied from the FPC 4018 to the separately formed signal line driver circuit 4003, the scan line driver circuit 4004, or the pixel portion 4002.

In addition, since the transistor is easily destroyed by static electricity or the like, it is preferable to provide a protection circuit for driving circuit protection on the same substrate as the gate line or the source line. It is preferable to comprise a protection circuit using the nonlinear element using an oxide semiconductor.

In FIG. 3C, the connection terminal electrode 4015 is formed of the same conductive film as the pixel electrode layer 4030, and the terminal electrode 4016 is formed of the same conductive film as the source electrode layer and the drain electrode layer of the transistor 4010 and the transistor 4011. do.

The connection terminal electrode 4015 is electrically connected to the terminal of the FPC 4018 via the anisotropic conductive film 4019.

3A, 3B, and 3C show an example in which the signal line driver circuit 4003 is separately formed and mounted on the first substrate 4001, but is not limited to this configuration. The scan line driver circuit may be separately formed and mounted, or only a part of the signal line driver circuit or a part of the scan line driver circuit may be separately formed and mounted.

In addition, the structure of the transistor which can be applied to the liquid crystal display device disclosed in the present specification is not particularly limited, and for example, a stagger type of a top-gate structure or a bottom-gate structure ( staggered and planar, etc. may be used. The transistor may be a single gate structure in which one channel region is formed, a double gate structure in which two channels are formed, or a triple gate structure in which three channels are formed. Alternatively, a dual gate type may be provided having two gate electrode layers arranged above and below the channel region with the gate insulating layer interposed therebetween.

4 shows an example of a cross-sectional structure of a liquid crystal display device, in which an element substrate 2600 and an opposing substrate 2601 are fixed by a seal material 2602, and an element layer 2603 and a liquid crystal layer (including transistors) between them. 2604 is provided.

In the case of color display, light emitting diodes emitting a plurality of types of light emitting colors are disposed in the backlight unit. In the case of the RGB system, the red light emitting diode 2910R, the green light emitting diode 2910G, and the blue light emitting diode 2910B are disposed in a divided area in which a display area of the liquid crystal display device is divided into a plurality.

The polarizing plate 2606 is provided outside the opposing substrate 2601, and the polarizing plate 2607 and the optical sheet 2613 are disposed outside the element substrate 2600. The light source is composed of a red light emitting diode 2910R, a green light emitting diode 2910G, a blue light emitting diode 2910B, and a reflecting plate 2611, and the LED control circuit 2912 provided on the circuit board 2612 includes a flexible wiring board ( It is connected with the wiring circuit part 2608 of the element substrate 2600 through 2609, and the external circuits, such as a control circuit and a power supply circuit, are built-in.

The LED control circuit 2912 can emit LEDs individually to form a field-sequential liquid crystal display device.

This embodiment can be implemented in appropriate combination with any of the structures described in the other embodiments.

(Embodiment 3)

The semiconductor material used for the semiconductor layer of the transistor which the liquid crystal display device disclosed by this specification has is not specifically limited. An example of the material that can be used for the semiconductor layer of the transistor in this embodiment will be described.

The material for forming the semiconductor layer of the semiconductor device is an amorphous (amorphous, also referred to as "AS") semiconductor produced by the sputtering method or the vapor phase growth method using a semiconductor material gas represented by silane or germane, the above-mentioned Polycrystalline semiconductors or microcrystalline (also referred to as semi-amorphous or microcrystals, also referred to as "SAS") semiconductors in which an amorphous semiconductor is crystallized using light energy or thermal energy, and the like can be used. The semiconductor layer can be formed by sputtering, LPCVD, plasma CVD, or the like.

The microcrystalline semiconductor film belongs to an intermediate metastable state of amorphous and single crystal in consideration of Gibbs free energy. That is, it is a semiconductor having a free energy stable third state, has short-range order, and has lattice distortion. Columnar crystals or needle-shaped crystals grow in the normal direction with respect to the substrate surface. The microcrystalline silicon, a representative example of the microcrystalline semiconductor, shifts toward the lower wave side than the 520 cm ^-1 where the Raman spectrum represents single crystal silicon. In other words, the peak of the Raman spectrum of the microcrystalline silicon between 480cm ^-1 to 520cm ^-1 showing an amorphous silicon indicates a single crystalline silicon. Further, the microcrystalline semiconductor film contains at least 1 at.% Or more of hydrogen or halogen in order to terminate the unbound water (dangling bond). Further, by containing rare gas elements such as helium, argon, krypton, and neon to further promote lattice distortion, stability is increased to obtain a good microcrystalline semiconductor film.

The microcrystalline semiconductor film can be formed by a high frequency plasma CVD method having a frequency of several tens of MHz to several hundred MHz or a microwave plasma CVD apparatus having a frequency of 1 GHz or more. Typically, hydrogenated silicon such as SiH ₄ , Si ₂ H ₆ , SiH ₂ Cl ₂ , SiHCl ₃ , SiCl ₄ , SiF _4, and the like can be formed by diluting with hydrogen. Further, in addition to silicon hydride and hydrogen, a microcrystalline semiconductor film can be formed by diluting with one or a plurality of rare gas elements selected from helium, argon, krypton, and neon. At this time, the flow rate ratio of hydrogen to silicon hydride is 5 times or more and 200 times or less, preferably 50 times or more and 150 times or less, more preferably 100 times.

Typical examples of the amorphous semiconductor include hydrogenated amorphous silicon and typical examples of the crystalline semiconductor include polysilicon and the like. Polysilicon (polycrystalline silicon) includes so-called high-temperature polysilicon using polysilicon formed at a process temperature of 800 ° C. or higher as a main material, and so-called low-temperature polysilicon using polysilicon formed at a process temperature of 600 ° C. or lower as a main material, which promotes crystallization. Polysilicon obtained by crystallizing amorphous silicon using an element or the like. Of course, as described above, a microcrystalline semiconductor or a semiconductor including a crystal phase in a part of the semiconductor layer may be used.

As the semiconductor material, compound semiconductors such as GaAs, InP, SiC, ZnSe, GaN, SiGe, etc., other than single bodies such as silicon (Si) and germanium (Ge) can also be used.

In the case of using a crystalline semiconductor film for the semiconductor layer, various methods (such as laser crystallization method, thermal crystallization method, or thermal crystallization method using an element that promotes crystallization such as nickel) can be used for the method for producing the crystalline semiconductor film. good. In addition, crystallinity may be enhanced by laser irradiation of a microcrystalline semiconductor which is SAS. If no element promoting crystallization is introduced, the hydrogen content of the amorphous silicon film is kept to 1 × 10 ²⁰ atoms / cm ³ or less by heating at 500 ° C. under nitrogen atmosphere for 1 hour before irradiating the laser light to the amorphous silicon film. Release. This is because irradiating laser light to an amorphous silicon film containing a lot of hydrogen destroys the amorphous silicon film.

The method of introducing a metal element into an amorphous semiconductor film is not particularly limited as long as it can be present on or inside the amorphous semiconductor film. For example, a sputtering method, a CVD method, and a plasma processing method (plasma CVD method also) Containing), adsorption, or a method of applying a solution of a metal salt. The method of using a solution in the said method is useful at the point which is simple and the concentration adjustment of a metal element is easy. In this case, in order to improve the wettability of the surface of the amorphous semiconductor film and to spread the aqueous solution over the entire surface of the amorphous semiconductor film, UV light irradiation in an oxygen atmosphere, a thermal oxidation method, treatment with ozone water or hydrogen peroxide containing hydroxy radicals, or the like may be used. It is preferable to form an oxide film.

In the crystallization step of crystallizing the amorphous semiconductor film to form a crystalline semiconductor film, an element (also referred to as a catalyst element or a metal element) that promotes crystallization is added to the amorphous semiconductor film, followed by heat treatment (from 3 minutes to 550 ° C. to 750 ° C.). Crystallization in 24 hours). Elements that promote crystallization include iron (Fe), nickel (Ni), cobalt (Co), ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), and platinum (Pt) ), Copper (Cu), and gold (Au) may be used one or a plurality of kinds.

In order to remove or alleviate the element which promotes crystallization from the crystalline semiconductor film, it is contacted with the crystalline semiconductor film to form a semiconductor film containing impurity elements, and functions as a gettering sink. As the impurity element, an impurity element imparting an n-type, an impurity element imparting a p-type, a rare gas element, or the like can be used. For example, phosphorus (P), nitrogen (N), arsenic (As), and antimony (Sb) can be used. ), Bismuth (Bi), boron (B), helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe) may be used. A crystalline semiconductor film containing an element that promotes crystallization is contacted to form a semiconductor film containing a rare gas element and subjected to heat treatment (3 minutes to 24 hours at 550 占 폚 to 750 占 폚). The element which promotes crystallization contained in the crystalline semiconductor film is moved into the semiconductor film containing the rare gas element so that the element which promotes crystallization in the crystalline semiconductor film is removed or reduced. Then, the semiconductor film containing the rare gas element which became a gettering sink is removed.

Crystallization of the amorphous semiconductor film may be performed by combining heat treatment and crystallization by laser light irradiation, or may be performed a plurality of times by heat treatment or laser light irradiation alone.

Further, the crystalline semiconductor film may be formed directly on the substrate by the plasma method. Further, the crystalline semiconductor film may be selectively formed on the substrate by the plasma method.

In addition, an oxide semiconductor may be used for the semiconductor layer. For example, zinc oxide (ZnO), tin oxide (SnO ₂ ), or the like can also be used. When ZnO is used for the semiconductor layer, Y ₂ O ₃ , Al ₂ O ₃ , TiO ₂ , a lamination thereof, and the like are used, and ITO, Au, Ti, and the like are used as the gate electrode layer, the source electrode layer, and the drain electrode layer. Can be used. Moreover, In, Ga, etc. can also be added to ZnO.

As the oxide semiconductor, a thin film represented by InMO ₃ (ZnO) _m (m> 0) can be used. In addition, M represents one metal element or a plurality of metal elements selected from gallium (Ga), iron (Fe), nickel (Ni), manganese (Mn), and cobalt (Co). For example, when M is Ga, the said metallic elements other than Ga, such as Ga and Ni, or Ga and Fe, may be contained. In addition, a transition metal element such as Fe or Ni or an oxide of the transition metal may be contained as an impurity element in addition to the metal element contained as M in the oxide semiconductor. For example, an In—Ga—Zn—O based non-single crystal film can be used as the oxide semiconductor layer.

As an oxide semiconductor layer (InMO ₃ (ZnO) _m (m> 0) film), an InMO ₃ (ZnO) _m (m> 0) film having M as another metal element is used instead of the In-Ga-Zn-O based non-single crystal film. You may also do it.

This embodiment can be implemented in appropriate combination with any of the structures described in the other embodiments.

(Fourth Embodiment)

The liquid crystal display device disclosed herein can be applied to various electronic devices (including game machines). As the electronic device, for example, a television device (also called a television or a television receiver), a monitor for a computer, a camera such as a digital camera or a digital video camera, a digital photo frame, a mobile phone (also called a mobile phone or a mobile phone device). ), Large game machines such as portable game machines, portable information terminals, sound reproducing apparatuses, and pachinko machines.

FIG. 5A illustrates an electronic book (also referred to as an E-book) and may include a case 9630, a display portion 9331, an operation key 9632, a solar cell 9633, and a charge / discharge control circuit 9634. The electronic book shown in FIG. 5A has a function of displaying various types of information (still images, moving images, text images, etc.), a function of displaying a calendar, a date or time, etc. on a display portion, a function of operating or editing information displayed on a display portion, It may have a function of controlling a process by various software (program). 5A shows a configuration with a battery 9635 and a DCDC converter (hereinafter abbreviated as a converter) 9636 as an example of the charge / discharge control circuit 9634. By applying the liquid crystal display device described in the above embodiment to the display portion 9631, an electronic book with high reliability can be obtained.

In the case of using the transflective liquid crystal display device or the reflective liquid crystal display device as the display portion 9631, since it is expected to be used under a relatively bright environment, the power generation by the solar cell 9633 and the battery may be achieved by the configuration shown in FIG. 5A. It is preferable because charging to 9635 can be performed efficiently. Moreover, since the solar cell 9633 can be suitably installed in the empty space (surface or back surface) of the case 9630, it can be set as the structure which can charge the battery 9635 efficiently. In addition, using a lithium ion battery as the battery 9635 has an advantage of miniaturization and the like.

The configuration and operation of the charge / discharge control circuit 9634 shown in FIG. 5A will be described using the block diagram of FIG. 5B. FIG. 5B shows a solar cell 9633, a battery 9635, a converter 9636, a converter 9637, a switch SW1 to a switch SW3, and a display portion 9631, and a battery 9633 and a converter 9636. ), Converter 9637 and switches SW1 to SW3 correspond to the charge / discharge control circuits 9634.

First, an example of operation in the case of generating power by the solar cell 9633 using external light will be described. The power generated by the solar cell 9633 is stepped up or down by the converter 9636 so as to be a voltage for charging the battery 9635. When the power from the solar cell 9633 is used for the operation of the display portion 9631, the switch SW1 is turned on to thereby boost or lower the voltage to the voltage required for the display portion 9631 by the converter 9637. In addition, when not displaying on the display part 9631, it is good to set it as the structure which charges the battery 9635 by turning off switch SW1 and turning on switch SW2.

Next, an example of operation in the case where power is not generated by the solar cell 9633 using external light will be described. The electric power stored in the battery 9635 is boosted or stepped down by the converter 9637 by turning on the switch SW3. Then, the power from the battery 9635 is used for the operation of the display portion 9631.

In addition, although the example which uses the solar cell 9633 as an example of a charging means is described, the structure which charges the battery 9635 by another means may be sufficient. Moreover, the structure which charges in combination with another charging means may be sufficient.

Fig. 6A is a notebook personal computer, which is composed of a main body 3001, a case 3002, a display portion 3003, a keyboard 3004, and the like. By applying the liquid crystal display device described in the above embodiment to the display portion 3003, a highly reliable notebook personal computer can be obtained.

6B is a portable information terminal (PDA), and a display portion 3023, an external interface 3025, an operation button 3024, and the like are provided on a main body 3021. There is also a stylus 3022 as an operation accessory. By applying the liquid crystal display device described in the above embodiment to the display portion 3023, a highly reliable portable information terminal PDA can be obtained.

6C shows an example of an electronic book. For example, the electronic book 2700 is composed of two cases, a case 2701 and a case 2703. The case 2701 and the case 2703 are integrated by the shaft portion 2711, and the opening and closing operation can be performed using the shaft portion 2711 as the shaft. With such a configuration, it can be treated like a book made of paper.

The display portion 2705 is built into the case 2701, and the display portion 2707 is built into the case 2703. The display unit 2705 and the display unit 2707 may be configured to display continuous screens, or may be configured to display different screens. By setting the structure to display different screens, for example, sentences can be displayed on the right display unit (display unit 2705 in FIG. 6C) and images can be displayed on the left display unit (display unit 2707 in FIG. 6C). have. By applying the liquid crystal display device described in the above embodiment to the display portion 2705 and the display portion 2707, a highly reliable electronic book can be obtained.

6C illustrates an example in which the operation unit and the like are provided in the case 2701. For example, the case 2701 includes a power supply 2721, an operation key 2723, a speaker 2725, and the like. The page can be turned by the operation key 2723. In addition, it is good also as a structure provided with a keyboard, a pointing device, etc. on the same surface as the display part of a case. Further, a configuration may be provided on the back and side surfaces of the case, including external connection terminals (earphone terminals, USB terminals, etc.), recording medium insertion portions, and the like. The electronic book 2700 may be configured to have a function as an electronic dictionary.

The electronic book 2700 may be configured to transmit and receive information wirelessly. It is also possible to have a configuration for purchasing and downloading desired book data or the like from the electronic book server by wireless.

6D shows a mobile phone and is composed of two cases, a case 2800 and a case 2801. The case 2801 includes a display panel 2802, a speaker 2803, a microphone 2804, a pointing device 2806, a camera lens 2807, an external connection terminal 2808, and the like. The case 2800 also includes a solar cell 2810 for charging a mobile phone, an external memory slot 2811, and the like. In addition, the antenna is built in the case 2801. By applying the liquid crystal display device described in the above embodiment to the display panel 2802, a highly reliable mobile phone can be obtained.

In addition, the display panel 2802 has a touch panel, and shows a plurality of operation keys 2805 displayed in a dotted line in FIG. 6D. In addition, a booster circuit for boosting the voltage output from the solar cell 2810 to a voltage required for each circuit is also mounted.

The display direction of the display panel 2802 is appropriately changed depending on the use form. In addition, since the camera lens 2807 is provided on the same plane as the display panel 2802, video telephony is possible. The speaker 2803 and the microphone 2804 are not limited to a voice call, but can make a video call, record, play, and the like. In addition, as shown in FIG. 6D, the case 2800 and the case 2801 can slide in an overlapped state from an unfolded state, thereby miniaturizing the portable device.

The external connection terminal 2808 can be connected to various cables such as a USB cable and an AC adapter, and can communicate with data such as a charge and a personal computer. In addition, a recording medium can be inserted into the external memory slot 2811 to cope with a larger amount of data storage and movement.

In addition to the above functions, an infrared communication function, a television reception function, or the like may be provided.

FIG. 6E is a digital video camera, and is composed of a main body 3051, a display portion (A) 3057, an eyepiece portion 3053, an operation switch 3054, a display portion (B) 3055, a battery 3056, and the like. By applying the liquid crystal display device described in the above embodiment to the display portion (A) 3057 and the display portion (B) 3055, a highly reliable digital video camera can be obtained.

6F shows an example of a television apparatus. The television unit 9600 includes a display portion 9603 in a case 9601. An image may be displayed on the display portion 9603. In addition, the structure which supported the case 9601 by the stand 9605 is shown here. By applying the liquid crystal display device described in the above embodiment to the display portion 9603, a television device having high reliability can be obtained.

The television device 9600 can be operated by an operation switch included in the case 9601 or a separate remote control manipulator. It is also possible to provide a remote control manipulator with a display unit for displaying information output from the remote control manipulator.

The television device 9600 is configured to include a receiver, a modem, and the like. A general television broadcast can be received by a receiver, and also by connecting to a wired or wireless communication network via a modem, information communication in one direction (sender to receiver) or in two directions (between the sender and receiver or between receivers, etc.). You may.

This embodiment can be implemented in appropriate combination with any of the structures described in the other embodiments.

(Example)

In the present Example, the liquid crystal display device produced by applying Embodiment 1 is demonstrated with a comparative example.

The structural formula of the organic compound used in the present Example is shown below.

The manufacturing method of the liquid crystal display device of a present Example and the liquid crystal display device of a comparative example is described below.

(Manufacturing method of liquid crystal display device of this embodiment)

First, a resin-made gap spacer having a height of 4 µm and a photocurable and heat curable seal material (SD-25, manufactured by SEKISUI CHEMICAL CO., LTD.) Were formed on a 5-inch glass substrate used as the first substrate. In addition, a circuit such as a transistor including an electrode layer for driving the liquid crystal layer was formed on a 5-inch glass substrate used as the second substrate.

Next, the seal material was temporarily cured by irradiating ultraviolet rays (11 mW / cm ² ) having 365 nm as the main wavelength to the first substrate on which the seal material was formed.

Next, the liquid crystal composition which has a commercially available material shown in following Table 1 was dripped inside the sealing material on a 1st board | substrate.

The phase transition temperature of the blue phase and isotropic phase of the liquid crystal composition shown in Table 1 was 31.3 degreeC. In addition, the phase transition temperature of the blue phase and the isotropic phase was 44.7 degreeC in the state which mixed only the liquid crystal material and a chiral agent in the liquid crystal composition.

When the liquid crystal composition was added dropwise, the temperature of the liquid crystal composition was set to 70 ° C which expresses an isotropic phase, and a liquid crystal material having an amount of about 14 mg was dropped into the inside of the sealing material.

Next, the second substrate was bonded to the first substrate. Here, the second substrate is fixed to the upper side of the chamber by an electrostatic chuck, and the first substrate on which the liquid crystal composition is dropped is installed on the lower side of the chamber, and the inside of the chamber is decompressed to 100 Pa to reduce the first substrate and the first substrate. 2 substrates were bonded together. Thereafter, the chamber was opened to the atmosphere.

Next, an isotropic phase was expressed by arranging a substrate on a stage having a heat source and heating the liquid crystal layer sandwiched between the first substrate and the second substrate to 70 ° C.

Next, while performing a polymer stabilization process to the liquid crystal layer which shows an isotropic phase, it was set as the liquid crystal layer which shows a blue phase. In the polymer stabilization treatment, the liquid crystal layer is rapidly cooled to −5 ° C./min up to 34 ° C., followed by maintaining 34 ° C. in which the isotropic phase is spread over the entire surface, and applying ultraviolet light (1.5 mW / cm ² ) having a wavelength of 365 nm for 30 minutes. Investigation was carried out.

Next, the sealing material was completely cured by heat treatment. The liquid crystal display device of this example was produced through the above process.

(Production Method of Liquid Crystal Display of Comparative Example)

In the liquid crystal display device of a comparative example, the process until joining a 1st board | substrate and a 2nd board | substrate was performed similarly to the liquid crystal display device of this Example mentioned above.

After the bonding step, the polymer stabilization treatment was performed on the liquid crystal layer sandwiched between the first substrate and the second substrate. In the polymer stabilization treatment, the liquid crystal layer is heated to 70 ° C., and then cooled to 70 ° C. at −1 ° C./min. The phase transition from the isotropic phase to the blue phase is maintained and the temperature at which the blue phase is spread over the entire surface is maintained. 1.5mW / cm ² ) was carried out for 30 minutes. The temperature at the time of irradiation employ | adopted two conditions, 28 degreeC and 30 degreeC.

Next, the sealing material was completely cured by heat treatment. The liquid crystal display device of a comparative example was produced through the above-mentioned process.

7A is an appearance photograph of the liquid crystal display of the present embodiment. 7B is an external photograph of the liquid crystal display device of the comparative example which maintained the polymer stabilization process at 28 degreeC, and FIG. 7C is an external photograph of the liquid crystal display device of the comparative example which maintained the polymer stabilization process at 30 degreeC.

Referring to FIG. 7B, in the liquid crystal display device of the comparative example maintained at 28 ° C. and subjected to the polymer stabilization treatment, light leakage due to phase transition to the cholesteric phase occurred in the entire surface of the display area. In addition, in FIG. 7C, in the liquid crystal display device of the comparative example maintained at 30 ° C. and subjected to the polymer stabilization treatment, alignment defects were suppressed more than in FIG. 7B, but there were regions in which light leakage occurred in the display area, particularly around the sealant. On the other hand, as shown in FIG. 7A, the alignment defect was not confirmed in the display area of the liquid crystal display device of the present embodiment.

As mentioned above, it turned out that the orientation defect of a liquid crystal display device can be suppressed using the manufacturing method which is one form of this invention.

100: substrate
102: seal material
106: liquid crystal composition
108: substrate
110: liquid crystal layer
112: liquid crystal layer
114: liquid crystal layer
200: dashed line
202: dashed line
2600: device substrate
2601: opposing substrate
2602: sealing material
2603: device layer
2604: liquid crystal layer
2606: polarizer
2607: polarizer
2608: wiring circuit section
2609: flexible wiring board
2611: reflector
2612: circuit board
2613: optical sheet
2700: electronic books
2701: case
2703: case
2705: display unit
2707: display unit
2711: shaft
2721: power
2723: operation keys
2725: speaker
2800: case
2801: case
2802: display panel
2803: speaker
2804: microphone
2805: operation keys
2806: pointing device
2807: camera lens
2808: external connection terminal
2810: solar cell
2910B: Light Emitting Diode
2910G: Light Emitting Diodes
2910R: Light Emitting Diode
2811: external memory slot
2912: LED control circuit
3001: main body
3002: case
3003: display unit
3004: keyboard
3021: main body
3022: stylus
3023: display unit
3024: Operation Button
3025: external interface
3051: body
3053: eyepiece
3054: operation switch
3055: Display portion B
3056: battery
3057: display unit (A)
4001: substrate
4002: pixel portion
4003: signal line driver circuit
4003a: signal line driver circuit
4003b: signal line driver circuit
4004: scan line driving circuit
4005: seal material
4006: substrate
4008: liquid crystal layer
4010: transistor
4011: transistor
4013: liquid crystal element
4015: connecting terminal electrode
4016: terminal electrode
4018: FPC
4019: anisotropic conductive film
4020: insulation layer
4021: insulation layer
4030: pixel electrode layer
4031: common electrode layer
4034: shading layer
4035: spacer
9600: television device
9601 cases
9603: display unit
9605: stand
9630: case
9631: display unit
9632: Operation keys
9633: solar cell
9634: charge and discharge control circuit
9635: battery
9636: converter
9637: Converter

Claims (12)

Sandwiching a liquid crystal layer containing a liquid crystal composition and preparing a first substrate and a second substrate bonded to each other using a sealing material;
Performing heat treatment to make the alignment state of the liquid crystal layer isotropic;
Irradiating light to the liquid crystal layer so that the polymer stabilization treatment is performed on the liquid crystal layer,
The alignment state of the liquid crystal layer is changed from an isotropic phase to a blue phase during the light irradiation. The method of claim 1,
The said composition contains the liquid crystal material, a chiral agent, photocurable resin, and the photoinitiator, The manufacturing method of the liquid crystal display device. The method of claim 2,
And said photocurable resin is polymerized by said light. Forming a seal member to form a mold on the first substrate;
Dropping a liquid crystal composition into a mold formed of the seal member;
Bonding a second substrate to the first substrate under reduced pressure to form a liquid crystal layer;
Performing heat treatment to make the alignment state of the liquid crystal layer isotropic;
Irradiating light to the liquid crystal layer so that the polymer stabilization treatment is performed on the liquid crystal layer,
The alignment state of the liquid crystal layer is changed from an isotropic phase to a blue phase during the light irradiation. The method of claim 4, wherein
The said composition contains the liquid crystal material, a chiral agent, photocurable resin, and the photoinitiator, The manufacturing method of the liquid crystal display device. The method of claim 5, wherein
And said photocurable resin is polymerized by said light. Forming a seal member to form a mold on the first substrate;
Temporarily curing the seal member by irradiating light;
Dropping a liquid crystal composition into a mold formed of the temporarily cured seal material;
Bonding a second substrate to the first substrate under reduced pressure to form a liquid crystal layer;
Performing heat treatment to make the alignment state of the liquid crystal layer isotropic;
Irradiating light on the liquid crystal layer such that the seal material is completely cured and polymer stabilization is performed on the liquid crystal layer,
The alignment state of the liquid crystal layer is changed from an isotropic phase to a blue phase during the light irradiation. The method of claim 7, wherein
The said composition contains the liquid crystal material, a chiral agent, photocurable resin, and the photoinitiator, The manufacturing method of the liquid crystal display device. The method of claim 8,
And said photocurable resin is polymerized by said light. Forming a seal member to form a mold on the first substrate;
Dropping a liquid crystal composition into a mold formed of the seal member;
Temporarily curing the seal member by irradiating light;
Bonding a second substrate to the first substrate under reduced pressure to form a liquid crystal layer;
Performing heat treatment to make the alignment state of the liquid crystal layer isotropic;
Irradiating light on the liquid crystal layer such that the seal material is completely cured and polymer stabilization is performed on the liquid crystal layer,
The alignment state of the liquid crystal layer is changed from an isotropic phase to a blue phase during the light irradiation. 11. The method of claim 10,
The said composition contains the liquid crystal material, a chiral agent, photocurable resin, and the photoinitiator, The manufacturing method of the liquid crystal display device. The method of claim 11,
And said photocurable resin is polymerized by said light.

Images