JP3247890B2 - Manufacturing method of liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a liquid crystal display device which is excellent in productivity and capable of obtaining excellent uniformity of alignment in the full surface of a liquid crystal display panel by providing a stage for interposing ferroelectric polymer liquid crystal from which two separator sheets are stripped between two electrode substrate having transparent electrodes. SOLUTION: A ferroelectric polymer liquid crystal material 3 which is dissolved a solvent to heighten its fluidity is applied on a conductive film 2 of one of the separator sheets 4 by a micro gravure method. An interposing body 6 formed by interposing thus obtained ferroelectric polymer liquid crystal 3 between two separator sheets 4 and 4' is applied with an electric field and a mechanical alignment method to subject the ferroelectric polymer liquid crystal 3 interposed between two separator sheets 4 and 4' to aligning treatment. Then the separator sheets 4 and 4' are stripped from the ferroelectric polymer liquid crystal 3 subjected to the aligning treatment and liquid crystal display panel substrates are stuck to both surface of the ferroelectric polymer liquid crystal 3 so that their transparent electrodes are opposed to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a liquid crystal display device used as a display of an electronic apparatus, and more particularly to a method for manufacturing a liquid crystal display device using a ferroelectric polymer liquid crystal. It is.

[0002]

2. Description of the Related Art As a general alignment processing method in a conventional method of manufacturing a liquid crystal display device using a ferroelectric liquid crystal material, a method of aligning a liquid crystal optical element disclosed in JP-A-5-289080 is disclosed. And its device ".

Here, the orientation treatment method will be described with reference to FIG.

First, a liquid crystal display panel 40 is manufactured by sandwiching a ferroelectric liquid crystal material between two flexible electrode substrates formed by patterning a transparent electrode made of ITO or the like in a stripe pattern.

As shown in FIG. 6, the liquid crystal display panel 40 is sandwiched between an upper belt 32a for applying a positive voltage with electrodes and a belt 34a for applying a negative voltage with electrodes, and together with the conductive belts 32a, 34a. , Guide roller 32
b, 32c, 34b, 34c, positive voltage applying roller 32
d, using the negative voltage applying roller 34d and the orientation roller section 36 to convey the inside of the orientation processing apparatus.

At this time, the liquid crystal display panel 40 is conveyed while changing its suspension direction for each of the alignment rollers 36 such that the front and back surfaces of the liquid crystal display panel 40 alternately contact the front side of the alignment rollers 36. In this state, the ferroelectric liquid crystal material is oriented by applying an electric field and a shear stress due to bending deformation while applying a voltage between the electrodes of the liquid crystal display panel 40.

[0007]

However, in the alignment processing method disclosed in Japanese Patent Application Laid-Open No. Hei 5-289080 shown in the related art, as described above, an electric field is applied to the transparent electrode pattern formed on the liquid crystal display panel. Since the shear stress is applied, the applied electric field differs between the portion where the transparent electrode pattern is formed and the portion where the transparent electrode pattern is not formed, and therefore, depending on the shape of the transparent electrode pattern,
There has been a problem that sufficient alignment uniformity cannot be obtained.

In addition, a shear stress due to bending deformation is applied between two flexible electrode substrates formed by patterning a transparent electrode in a stripe shape while holding a ferroelectric liquid crystal material. In addition, problems such as disconnection of the transparent electrode pattern and increase in resistance value have occurred.

The present invention has been made to solve such a problem, and its object is to solve the above-mentioned problem.
Alignment treatment is performed with the ferroelectric polymer liquid crystal sandwiched between two separator sheets, and then the alignment is performed by using a method in which only the ferroelectric polymer liquid crystal layer is sandwiched between the electrode substrates. It is an object of the present invention to provide a liquid crystal display device using a ferroelectric polymer liquid crystal which is excellent in uniformity and productivity and is very thin and light.

[0010]

A method of manufacturing a liquid crystal display device according to the present invention is a method of manufacturing a liquid crystal display device in which a ferroelectric polymer liquid crystal is sandwiched between two electrode substrates having transparent electrodes. A step of sandwiching the ferroelectric polymer liquid crystal between two separator sheets and performing an alignment treatment in that state; and separating the two separator sheets from the aligned ferroelectric polymer liquid crystal. A step of sandwiching the ferroelectric polymer liquid crystal from which the two separator sheets have been peeled between two electrode substrates having the transparent electrode;
Therefore, the above object is achieved.

At this time, a conductive film may be formed on the surface of the separate sheet.

According to the present invention, a conventional ferroelectric polymer liquid crystal is sandwiched between two separator sheets, and an orientation process for applying an electric field, a shear stress, or the like is performed in that state, thereby providing a conventional electrode pattern-equipped liquid crystal display. Compared to a method of performing an orientation treatment in which an electric field, a shear stress, or the like is applied in a state of being sandwiched between substrates, it is possible to obtain uniform orientation over the entire surface regardless of the presence or absence or shape of the electrode pattern.

The conductive film formed on the surface of the separator sheet (the surface in contact with the ferroelectric polymer liquid crystal) at this time does not need to be particularly transparent, and therefore has a low resistance value and excellent malleability. What is necessary is just to select a metal film and form it very thin. Therefore, in the separator sheet with the conductive film, even when the conductive sheet is deformed or bent, problems such as disconnection of the conductive film and an increase in the resistance value are less likely to occur, and a stronger orientation shear stress can be applied.

Further, when the alignment treatment is performed in a state where the ferroelectric polymer liquid crystal is sandwiched between the two separator sheets, by controlling the temperature, the electric field can be effectively applied to the ferroelectric polymer liquid crystal. And shear stress can be applied.

Further, by providing a very thin release treatment layer on the conductive film formed on the surfaces of the two separator sheets, a ferroelectric polymer liquid crystal layer obtained by subjecting the two separator sheets to an orientation treatment is provided. It is possible to improve the releasability at the time of peeling from the substrate.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for manufacturing a liquid crystal display device according to the present invention will be described in detail with reference to examples. However, the present invention is not limited to these examples. A hard coat layer, a gas barrier layer, an undercoat layer, or the like may be formed on a sheet, a glass substrate, a polarizing plate, or a polarizing plate integrated with a reflector.

Embodiment 1 FIG. 1 is a schematic sectional view showing a state 6 in which ferroelectric polymer liquid crystal is sandwiched between two separator sheets in this embodiment. FIG. 2 is a schematic cross-sectional view of the completed liquid crystal display panel 10.
In the figure, 1 and 1 ′ are polycarbonate films,
2, 2 'is a conductive film, 3 is a ferroelectric polymer liquid crystal, 4, 4'
Indicates a separator sheet composed of the polycarbonate films 1 and 1 ′ and the conductive films 2 and 2 ′,
7, 7 'are polyethersulfone films, 8, 8' are transparent electrodes, 13 is a UV-curable sealing material, 9, 9 'are polyethersulfone films 7, 7' and transparent electrodes 8, 8 '. 1 shows a liquid crystal display panel substrate.

In this embodiment, the thickness of 0.1 mm
A molybdenum (Mo) film was formed as a conductive film 2 and 2 'on one surface of each of the polycarbonate films 1 and 1' by a magnetron sputtering method to produce two separator sheets 4 and 4 '.

At this time, on the conductive films 2, 2 'formed on the surfaces of the two separator sheets 4, 4', a silicone-based release layer as a very thin release treatment layer is heated after offset printing. Produced.

Next, a material obtained by dissolving the ferroelectric polymer liquid crystal material 3 with a solvent to increase the fluidity was applied to the conductive film 2 of the one separator sheet 4 by a microgravure method.

In this case, as the ferroelectric liquid crystal material 3,
For example, one or more ferroelectric polymer liquid crystal materials,
Ferroelectric polymer liquid crystal material composed of one or more ferroelectric polymer liquid crystal materials and one or more ferroelectric low molecular liquid crystal materials, one or more ferroelectric low molecular liquid crystal materials And a ferroelectric polymer liquid crystal material composed of one or more kinds of other polymer liquid crystal materials. That is, the ferroelectric polymer liquid crystal material used in the present embodiment is not limited to a ferroelectric polymer liquid crystal material in which the polymer molecules themselves exhibit ferroelectric liquid crystal characteristics, but also a polymer liquid crystal material in which all the ferroelectric properties are exhibited. It is possible to use, for example, acrylate main chain liquid crystal polymer, methacrylate main chain liquid crystal polymer, chloroacrylate main chain liquid crystal polymer, oxirane main chain liquid crystal polymer, siloxane main chain liquid crystal polymer, siloxane-olefin Main chain liquid crystal polymers, ester main chain liquid crystal polymers, and the like can be given. Among such ferroelectric polymer liquid crystal materials, it is preferable to use a side chain type ferroelectric polymer liquid crystal material having a chiral smectic C phase. Further, the ferroelectric polymer liquid crystal material at this time may contain an adhesive, a viscosity reducing agent, a non-liquid crystal chiral compound, a dye, and the like, if necessary.

After the solvent in the ferroelectric polymer liquid crystal material 3 is evaporated, the other separator sheet 4
Was attached so that the conductive film 2 ′ side of the separator sheet 4 ′ was in contact with the surface of the ferroelectric polymer liquid crystal 3.

The ferroelectric polymer liquid crystal 3 thus obtained is sandwiched between two separator sheets 4 and 4 ', and an electric field and mechanical alignment method is applied to the two separator sheets. The alignment treatment was performed on the ferroelectric polymer liquid crystal layer 3 sandwiched between 4, 4 '.

A specific orientation treatment method at this time is shown in FIG.
As shown in the figure, a ferroelectric polymer liquid crystal 3 sandwiched between two separator sheets 4 and 4 ′ is sandwiched between two transporting and voltage applying belts 12 and 12 ′,
A state in which the ferroelectric polymer liquid crystal 3 is sandwiched between two separator sheets 4 and 4 ′ on the surface side of a plurality of alignment rollers 11 together with the conveyance and voltage application belts 12 and 12 ′. 6 so that the front and back surfaces of the ferroelectric polymer liquid crystal 3 are alternately brought into close contact with each other. The ferroelectric liquid crystal material 3 was subjected to an orientation treatment by applying an electric field and a shear stress due to bending deformation while applying a voltage to the ferroelectric liquid crystal material 6 held in the state.

In this embodiment, the viscosity of the liquid crystal layer was adjusted by controlling the temperature of the alignment roller so that a shearing stress could be effectively applied to the liquid crystal layer during the alignment treatment.

On the other hand, transparent electrodes 8 and 8 'were formed on one side of two polyethersulfone films 7 and 7' having a thickness of 0.1 mm by ITO (Ind.
(Im Tin Oxide) films were formed to produce two liquid crystal display panel substrates 9 and 9 ′.

Next, the separator sheets 4, 4 'are peeled off from the state 6 in which the oriented ferroelectric polymer liquid crystal 3 is sandwiched between two separator sheets 4, 4'. As shown in FIG. 3, the liquid crystal display panel substrates 9 and 9 ′ are attached to both surfaces of the ferroelectric polymer liquid crystal 3 exposed after peeling so that the transparent electrodes 8 and 8 ′ face each other. Thus, the liquid crystal display panel 10 was manufactured.

At this time, the liquid crystal display panel substrates 9, 9
′ At the time of sticking to the ferroelectric polymer liquid crystal 3
A UV curable resin having flexibility even after curing is applied as a sealant 13 to the outer peripheral portion of one of the liquid crystal display panel substrates 9 and 9 ′, and ultraviolet light is applied after the resin is applied to seal the seal. Material 13 was cured.

Thereafter, a polarizing plate was attached to the display surface side of the liquid crystal display panel 10 and a reflective plate-integrated polarizing plate was attached to the back surface side, thereby producing the liquid crystal display device of this embodiment.

In the present invention, a transmissive liquid crystal display device having a light source may be used. However, in order to take advantage of the feature of being extremely thin and light, a reflective liquid crystal display device as described in this embodiment is used. The device is preferred.

[Embodiment 2] FIG. 4 is a schematic sectional view of a liquid crystal display panel 16 completed according to the present embodiment. In the figure, 3 is a ferroelectric polymer liquid crystal, 7 is a polyethersulfone film, 8 , 8 ′ are transparent electrodes, 9 is a liquid crystal display panel substrate comprising the polyether sulfone film 7 and the transparent electrode 8, 14 is a glass substrate for liquid crystal display panel, 15 is a glass substrate for liquid crystal display panel 14 and the transparent The figure shows a liquid crystal display panel substrate composed of electrodes 8 '.

In this embodiment, after the orientation treatment of the ferroelectric polymer liquid crystal 3, as shown in FIG. 4, a photolithography method is used as a transparent electrode 8 on one side of a 0.1 mm thick polyester sulfone film 7. A liquid crystal display panel substrate 9 having an ITO film formed thereon, and a liquid crystal display panel substrate 15 having a 0.7 mm thick liquid crystal display panel glass substrate 14 having an ITO film formed on one surface thereof as a transparent electrode 8 using a photolithographic method. A liquid crystal display device was manufactured in the same manner as in Example 1 except that the above was combined.

REFERENCE EXAMPLE FIG. 5 is a schematic sectional view showing a state 17 in which a ferroelectric polymer liquid crystal is sandwiched between a separator sheet and a liquid crystal display panel in this reference example. Film, 2 is a conductive film,
3 is a ferroelectric polymer liquid crystal, 4 is a separator sheet composed of the polycarbonate film 1 and the conductive film 2, 7 'is a polyether sulfone film, 8'
′ Indicates a transparent electrode, and 9 ′ indicates a liquid crystal display panel substrate including the polyether sulfone film 7 ′ and the transparent electrode 8 ′.

In this embodiment, a transparent electrode 8 is provided on one side of a polyethersulfone film 7 ′ having a thickness of 0.1 mm.
An 'film was formed in the form of a stripe by using a photolithography method as a' to prepare a liquid crystal display panel substrate 9 '.

Further, a molybdenum (Mo) film was formed as a conductive film 2 on one side of a polycarbonate film 1 having a thickness of 0.1 mm by a magnetron sputtering method to produce a separator sheet 4.

Next, a material obtained by dissolving the ferroelectric polymer liquid crystal material 3 with a solvent to increase the fluidity was applied to the transparent electrode 8 'of the liquid crystal display panel substrate 9' by a microgravure method.

Thereafter, after the solvent in the ferroelectric polymer liquid crystal material 3 was evaporated, the separator sheet 4 was attached so that the conductive film 2 side of the separator sheet 4 was in contact with the surface of the ferroelectric polymer liquid crystal 3. .

The ferroelectric polymer liquid crystal 3 thus obtained is sandwiched between the liquid crystal display panel substrate 9 ′ and the separator sheet 4, and an electric field and a mechanical alignment method are applied to the liquid crystal display panel 17. The alignment treatment was performed on the ferroelectric polymer liquid crystal layer 3 sandwiched between the substrate 9 ′ and the separator sheet 4.

A specific orientation processing method at this time is to apply a mechanical orientation (shear stress) in a direction parallel to the pattern direction of the transparent electrode 7 'formed on the liquid crystal display panel substrate 9'. Other than that, the same method as in Example 1 was used.

On the other hand, an ITO film was formed as a transparent electrode 8 on one surface of a polyethersulfone film 7 having a thickness of 0.1 mm by a photolithography method, and a liquid crystal display panel substrate 9 similar to that of Example 1 was produced. .

Next, only the separator sheet 4 is peeled from the liquid crystal display panel substrate 9 ′ and the separator sheet 4 in which the ferroelectric polymer liquid crystal 3 subjected to the alignment treatment is sandwiched between the liquid crystal display panel substrate 9 ′ and the separator sheet 4. As shown in FIG. 3, on the surface of the ferroelectric polymer liquid crystal 3 exposed after peeling, the liquid crystal display panel substrate 9 is provided with the transparent electrode 8 and the liquid crystal display panel substrate 9.
The liquid crystal display panel 10 is adhered by the same method as in the first embodiment so as to face the transparent electrode 8 ′ of the liquid crystal display panel 10 ′.
Was prepared.

Thereafter, a polarizing plate was attached to the display surface side of the liquid crystal display panel 10 and a reflective plate-integrated polarizing plate was attached to the back surface side, whereby the liquid crystal display device of this embodiment was manufactured.

[0043]

According to the present invention, a ferroelectric polymer liquid crystal is sandwiched between two separator sheets each having a conductive film formed on the surface, and orientation treatment is performed in that state. Since a method is used in which only the layer is sandwiched between regular electrode substrates, a uniform electric field can be applied to the entire surface of the liquid crystal display panel during the alignment process, and the electric field is applied directly to the transparent electrode pattern as in the past. Compared to the method of applying a shear stress to the ferroelectric polymer liquid crystal layer while performing, the problem that the applied electric field differs due to the presence or absence and shape of the transparent electrode pattern does not occur, and the entire liquid crystal display panel is excellent. There is an effect that an excellent alignment uniformity can be obtained.

When applying a shear stress to the liquid crystal layer,
In the conventional method, it is necessary to deform the liquid crystal display panel substrate, and there is a problem such as disconnection of the transparent electrode pattern or an increase in the resistance value. In the present invention, however, two conductive films having excellent bending resistance and low resistance are used. Since the alignment treatment is performed while the ferroelectric polymer liquid crystal is sandwiched between the attached separator sheets, the above-described problems such as disconnection of the electrode pattern and increase in the resistance value do not occur. Therefore, it is possible to apply an even stronger shear stress than before, and as a result, it is possible to obtain a liquid crystal display panel having a strong alignment control force against deformation.

Furthermore, since the conductive film formed on the surface of the separator sheet (the surface in contact with the ferroelectric polymer liquid crystal) does not need to be transparent, a metal film having a low resistance value and excellent malleability is selected. However, since it is only necessary to form the separator sheet very thin, the separator sheet with the conductive film is less likely to be deformed or bent due to disconnection of the conductive film or an increase in the resistance value. It can be applied to molecular liquid crystals.

Further, since the separator sheet with the conductive film used in the present invention can be used repeatedly, it can be operated at low cost, and always performs a uniform alignment treatment regardless of the shape of the transparent electrode pattern of the liquid crystal display panel. The present invention can be applied to a substrate material, such as glass, which is difficult to apply shear stress due to deformation.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing a state in which a ferroelectric polymer liquid crystal in an embodiment of the present invention is sandwiched between two separator sheets.

FIG. 2 is a schematic cross-sectional view illustrating an alignment treatment method according to an example of the present invention.

FIG. 3 is a schematic sectional view of a liquid crystal display panel manufactured according to an example of the present invention.

FIG. 4 is a schematic cross-sectional view of a liquid crystal display panel manufactured according to an example of the present invention.

FIG. 5 is a schematic sectional view showing a state in which a ferroelectric polymer liquid crystal is sandwiched between a liquid crystal display panel substrate and a separator sheet in a reference example of the present invention.

FIG. 6 is a schematic cross-sectional view showing a general alignment processing method in a conventional method of manufacturing a liquid crystal display device using a ferroelectric liquid crystal material.

[Explanation of symbols]

Reference Signs List 1 polycarbonate film 1 ′ polycarbonate film 2 conductive film 2 ′ conductive film 3 ferroelectric polymer liquid crystal 4 separator sheet 4 ′ separator sheet 6 ferroelectric polymer liquid crystal sandwiched between two separator sheets 7 polyether sulfone film 7 'Polyether sulfone film 8 Transparent electrode 8' Transparent electrode 9 Liquid crystal display panel substrate 9 'Liquid crystal display panel substrate 10 Liquid crystal display panel 11 Orientation roller 12 Transport and electric field applying belt 12' Transport and electric field applying belt 13 Sealing material 14 Liquid crystal display Glass substrate for panel 15 Liquid crystal display panel substrate 16 Liquid crystal display panel 17 Ferroelectric polymer liquid crystal sandwiched between liquid crystal display panel substrate and separator sheet 32 Positive electric field applying section 32a Upper belt for applying positive voltage with electrodes 32b Guide roller 32c Idorora 32d positive voltage application roller 34 negative electric field applying part 34a negative voltage applied with the electrode lower belt 34b guide roller 34c guide rollers 34d negative voltage application roller 36 alignment rollers 40 liquid crystal display panel E voltage source

Claims (1)

(57) [Claims] 1. A method according to claim 1, further comprising the steps of:
A method of manufacturing a liquid crystal display device having a ferroelectric polymer liquid crystal interposed therebetween, comprising the steps of: interposing the ferroelectric polymer liquid crystal between two separator sheets and performing an alignment treatment in that state; Separating the separator sheet from the oriented ferroelectric polymer liquid crystal, and sandwiching the ferroelectric polymer liquid crystal from which the two separator sheets have been separated between two electrode substrates having the transparent electrodes. And a method of manufacturing a liquid crystal display device.