JPS58220121A - Electrooptical device - Google Patents

Abstract

PURPOSE:To obtain a cholesteric-nematic phase transition type liq. crystal display device utilizing a guest-host effect by holding a liq. crystal between a pair of electrode plates including an electrode plate having a cured resin layer and a protective layer laminated on the non-display region. CONSTITUTION:A liq. crystal layer 5 is held between an upper electrode plate obtd. by forming an electrode 3 on an upper substrate 1 and an under electrode plate obtd. by forming an electrode 4 on an under substrate 2. The layer 5 consists of a cholesteric-nematic phase transition type liq. crystal and a digenetic dye. The under electrode plate has the electrode 4 at the prescribed position of the under substrate 2 and a cured resin layer 6 of about 1-10mum thickness and a protective layer 7 of about 1,000-5,000Angstrom thickness laminated on the non- display region where no electrode is formed. The under electrode plate is adhered to the upper electrode plate with a sealing spacer 8 in-between, and the liq. crystal contg. the dye is injected into the resulting gap from the injection hole 9. The hole 9 is then sealed with a sealant to obtain a liq. crystal display device.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electro-optical device, and more particularly to a cholesteric-nematic phase transition type liquid crystal display device that utilizes the guest-host effect.

Liquid level display devices that utilize the guest-host effect can omit the use of polarizing plates, which allows for an increase in the amount of transmitted light, but it is not possible to increase the contrast between colored and non-colored areas. There are drawbacks. Therefore, in recent years, a method has been proposed in which the guest-host effect is applied to a type of liquid crystal mode that exhibits a cholesteric phase in a non-operating state and becomes a nematic phase in an operating state. This method has the advantage that the colored states during operation and non-operation can be displayed with a sufficiently large contrast.

However, in this method, the dichroic dyes are arranged in the non-display area according to the twisted structure of the cholesteric phase, resulting in an unnecessarily colored state. For this reason, for example, when a display device using this method is placed on the focus board of a camera and used for superimposition in the viewfinder,
It has the disadvantage that the image in the camera viewfinder becomes dark.

Therefore, in a phase change liquid crystal mode display device that utilizes the guest-host effect, it is necessary to make the cell thicknesses in the display area and the non-display area different, that is, to make the cell thickness in the non-display area sufficiently large. Attempts have been made to sufficiently reduce the colored state of the non-display area by thinning it. Therefore, conventionally, a resist film with a thickness of about 3 to 5 μm formed by a photolithography process is provided on the substrate in areas where no electrodes are provided, and by overlapping this with a counter electrode plate, the non-display area where no electrodes are provided. A method of reducing the cell thickness has been adopted, but 3- to 3-cell cells formed from photosensitive resins made of polyvinyl alcohol, gelatin, and ammonium dichromate used in the photolithography process have been adopted.
A resist film with a thickness of 5 μm is actually colored bright yellow, which poses many practical problems, and a resist film formed using an oil-based photosensitive resin liquid mainly composed of acrylic resin, polyvinyl cinnamate, or rubber-based resin. Although there are no problems such as coloring, there is a drawback that if the display device is left in a high-temperature environment of 60° C. or higher, its life span will be shortened. Although the cause of this is not clear at present, it is thought that the reaction with the liquid crystal is accelerated in a high temperature environment.

Accordingly, a first object of the present invention is to provide an electro-optical device, particularly a phase change mode liquid crystal display device that utilizes the guest-host effect, in which the colored state of non-display areas is sufficiently suppressed.

A second object of the present invention is to provide a phase transition mode liquid crystal display device that utilizes the guest-host effect and has a long lifespan.

A third object of the present invention is to provide a phase change mode liquid crystal display device that utilizes a novel guest-host effect that can be used for superimposition in a camera viewfinder.

Other objects of the invention will be readily apparent to those skilled in the art.

Such an object of the present invention is to provide a cured resin layer and a protective layer formed thereon in a non-display area on at least one electrode plate constituting an electro-optical device, and to make this electrode plate face a counter electrode plate. This is achieved by making the cell thickness in the areas with the above-mentioned layers thinner than in the areas with electrodes formed for display purposes.

The present invention will be explained below with reference to the drawings.

FIG. 1 is a plan view of a liquid crystal display device of the present invention that can be used for superimposition in a camera finder, and FIG. 2 is a sectional view taken along line A-A.

FIG. 3 is a sectional view of another liquid crystal display device of the present invention.

Note that the reference numerals in FIGS. 1 to 3 indicate the same members.

In FIGS. 1 and 2, a liquid crystal layer is formed between an upper electrode plate having an electrode 3 formed on an upper substrate 1 (glass, plastic plate, etc.) and a lower electrode plate having an electrode 4 formed on a lower substrate 2 (glass, plastic plate, etc.). 5 is arranged.

The liquid crystal layer 5 includes a cholesteric-nematic phase transition liquid crystal to which a dichroic dye is added.

The liquid crystal used in the present invention is suitably a nematic liquid crystal (hereinafter referred to as "Np liquid crystal") having positive dielectric anisotropy, and by adding an appropriate amount of an optically active substance and a dichroic dye to this liquid crystal, guests can - Can be used for phase transition liquid crystal mode using host effect.

Preferred Np liquid crystals used in the present invention are selected from Schiff base, ester, azo, azoxy, and biphenyl liquid crystals. So. Typical examples are listed below.

◎-cH-+N However, nH@ Cn Hl n + I COO'l≦n
≦8CnH1n+II≦n≦8 On) (2n+1(') -3≦n≦8R-@-AginC
N However, R2: CnH2n+1- 1≦n≦8CnH
,n+10- 1≦n≦8'RseCOshaCN) However, R3: CnH2n+1- 4≦n≦9Ctz
H1n+10 +, 5≦n≦9CnH2n+l
COO-4≦n≦7 Cn Hl n +10000-5≦n≦7n, (■
oc8CN 1 However, R4: Cnf(, n+1- 4≦n≦8Cn
Horse n+10- 5≦n≦8 To R) NtsuN (Death CN TL*+CN However, R,: CnHln + 1 4≦n≦9
However, R1 (1: CnH2m+1 4≦n≦8
B,,0(X■CN However, 811: CnH2n+1- 4≦n≦8
These liquid crystals may not only be used alone, but may also be selectively mixed as appropriate for the purpose of obtaining desired electro-optical properties, nematic liquid crystal temperature range, lifetime, etc. Nematic liquid crystals having negative dielectric anisotropy may also be used. You can also add .

The optically active substances used in the present invention include cholesteryl compounds such as cholesteryl chloride, cholesteryl bromide, cholesteryl iodite, cholesteryl formate, and cholesteryl acetate, and chiral nematic liquid crystals such as cholesteryl acetate. The active substance is N, 0.5 to 1 to 1 liquid crystal.
A phase change type liquid crystal can be obtained by adding 0% by weight of JO.

Further, the front side of the dichroic dye that can be used in the device of the present invention is as follows.

In the lower electrode plate used in the liquid crystal display device of the present invention, an electrode 4 is formed at a predetermined position on a lower substrate 2, and a cured resin layer 6 is formed in a non-display area where no electrode is formed. 10
A protective layer 7 having a thickness of 1,000 to 5,000 layers is provided thereon.

This lower electrode plate is prepared by spin-coating an ultraviolet curable resin solution such as ■FV-15 (manufactured by Fuji Yakuhin ■) at 100 Or, p, m for 10 seconds on the electrode-patterned substrate at 50℃~ Heat it at 100℃ for about 15 minutes to make it about 1-10
A 10% aqueous solution of polyvinyl alcohol (10% aqueous solution of polyvinyl alcohol) is added on top of which a photosensitive layer is formed with a thickness of μ.
Ammonium dichromate (containing 5% by weight based on the solid content of polyvinyl alcohol) was spin-coated at 600 Or, p, m for 10 seconds, dried at room temperature, and applied at approximately 1000 to 5000 A.
A photosensitive polyvinyl alcohol layer with a thickness of 15 to 20 m W/a is applied to the photosensitive layer through a predetermined exposure mask (the photosensitive layer coated on the electrode 4 is masked).
Ultraviolet irradiation was applied for 5 seconds at an intensity of m to photo-cure the specified areas, 1. Next, the uncured photosensitive polyvinyl alcohol was removed by washing with water, and the washing water was removed with a nitrogen gas blower. 2. After developing with FVR rinsing liquid (manufactured by Fuji Yakuhin ■), wash with FVR rinse liquid (Fuji Yakuhin ■), heat treatment at 200℃ to 250℃ for 15 minutes to heat cure the photocurable resin layer. The polyvinyl alcohol layer formed on this electrode plate has a thin film thickness of 1,000 to 5,000 λ, so yellow coloration is hardly observed visually.

This cured resin layer 6ii can also be provided to cover a portion of the electrode 4. At this time, when a voltage is applied between the electrode 4 partially covered with the cured resin layer 6 and the opposing electrode 3, the cell thickness between the electrode portion covered with the resin layer 6 and the opposing electrode is about 1~ Since it is sufficiently thin at 5 μm, the orientation hardly changes due to applied voltage, and therefore this area can be used as a non-display area.

After creating the lower electrode plate having the structure shown in FIG. 2 in this way,
The above-mentioned liquid crystal is injected from the injection port 9 into the gap formed by adhering to the upper electrode plate through the seal spacer 8, and then the gap is sealed with a suitable sealant lO to obtain the desired liquid crystal display device. At this time, the cell thickness between the electrodes is approximately 6 to 15 μm.
It is preferable that

The liquid crystal display device shown in FIG. 3 uses a lower electrode plate according to another embodiment of the present invention.

This lower electrode plate is made by forming a photosensitive layer by coating a photosensitive resin liquid such as (1) FVR-15 (same as above) on the substrate with the electrode patterned in the same manner as described above, and (2) forming a photosensitive layer on this photosensitive layer. UV irradiation is applied in the same way as described above through a photo mask to photocure the predetermined areas, and then FVRfJ1
After developing with Mons' solution (same as above), washing with FvR rinse solution (same as above), ■ After that, apply the photosensitive polyvinyl alcohol solution used above in the same manner to form a photosensitive layer, ■ Seal spacer s Ultraviolet rays are irradiated through an exposure mask so as to leave a film on Nouchi 11, and the uncured photosensitive layer is removed by washing with water. Next, heat treatment is performed at 200°C to 250°C for about 15 minutes to form a photocured layer. It can be created by heat curing.

In the liquid crystal display device of the present invention, the area where the cell thickness is thin corresponds to a non-display area, and this area can be observed as a light-colored area, while the area where the cell thickness is thick corresponds to an operation display area, where no voltage is displayed. When it is heated, it is in a dark colored state, but when a voltage is applied between the electrodes provided in this area, the liquid crystal molecules and the dichroic dye become parallel to the direction of the electric field, so it can be changed to a light colored state.

As the protective layer 7 in the liquid crystal display device of the present invention, in addition to the above-mentioned photosensitive liquid made of anthrocyonium dichromate and polyvinyl alcohol, a water-soluble photosensitive resin liquid such as a photosensitive liquid made of dichromate and gelatin is used. However, the present invention is not necessarily limited to the use of such a photosensitive liquid. For example, when creating the electrode plate shown in FIG. 3, a protective layer of polyimide, polyamide, polyvinyl butyral, polyvinyl acetal, polyvinyl styrene, etc. is applied to the cured resin layer 6 formed on the electrode patterned substrate 2. 7 can also be provided.

At this time, the part of the seal spacer 8 and its outer part,
Etching can be performed using a normal photolithography process.

Further, as the photosensitive liquid used when forming the cured resin layer 6 in the apparatus of the present invention, the above-mentioned oil-based FVR-15 (
P-phenylene bis azide, 4.4.
An i-type photosensitive resin liquid containing an azide compound such as '-diazidobenzophenone, 4.4-diazidodiphenylmethane, 4.4'-diazidodiphenyl sulfide, 4,4-diazidostilbene, etc. can be used. .

Specifically, "0DU" made by Tokyo Ohka ■, "0DtJRx 20 J" made by Tokyo Ohka, "0DtJRx 20
10J, "0DUR1013" manufactured by the same company, or 1 manufactured by the same company
'-0DUR1014J and other deep ultraviolet curable resin liquids,
Examples include ultraviolet curable resin liquids such as OMR-85J manufactured by the same company. These developers generally include pentane, cyclopentane, pentene, pentyne, hexane, cyclohexane, hexene, hexyne, heptane,
Cycloheptane, heptene, heptyne, octane, cyclooctane, octene, octyne, nonane, cyclononane, nonene, nonine, decane, cyclodecane, decene,
Teshin, undecane, cycloundecane, undecene,
Aliphatic carbonization such as undecine, dodecane, cyclododecane, dodecane/, dobuscine, etc.) Aromatics such as luene, xylene, benzene, ligroin, monochlorobenzene, dichlorobenzene, ketones such as acetone, methyl ethyl ketone, cyclohexanone, etc. Alcohols such as methanol, ethanol and isopropanol, and ethers such as tetrahydrofuran and dioxane can be used alone or in combination.

The liquid crystal display device of the present invention may be of a static drive type or of a dynamic drive type, and may be of a matrix display type instead of a segment display type.

According to the present invention, the light transmittance in the non-display area can be sufficiently increased, and the durability under a high temperature environment can be significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the liquid crystal display device of the present invention, and is a sectional view taken along the line A-f in FIG. 2. FIG. 3 is a sectional view of a liquid crystal display device showing another embodiment of the present invention.

Claims (1)

[Claims] An electro-optical device having a liquid crystal between a pair of electrode plates, characterized in that at least one of the pair of electrode plates has a cured resin layer in its non-display area and a protective layer provided thereon. electro-optical device.