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US 5,178,571 AGranted
Method for manufacturing an electro-optical device
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorAkira Mase
Life of this patent
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AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorAkira Mase
Estimating the term…
A method for manufacturing an electro-optical device is disclosed. The first step of the method is distributing on a substrate at a thickness of 1 to 500 pm a mixture which comprises spacers having a diameter of 1 to 50 pm and plastic spherical covers having an inner diameter of 0.2 to 50 pm and containing a liquid crystal therein and coated with heat curable resin or photocurable resin or a polymerizable material on the outside surfaces thereof. Secondly, the substrate is joined to another substrate with the distributed mixture therebetween. Finally, the joined substrates are pressed against each other under an environmental pressure less than atmospheric pressure. In case of the heat curable resin, said pressing step is carried out with the substrates heated. In case of the photocurable resin, said pressing step is carried out with the distributed mixture irradiated with light. In case of the polymerizable, material, the material is polymerized during said pressing step. Liquid crystal devices having a more distinct threshold value and hence having an increased drive margin are realized.
A method for manufacturing an electro-optical device comprising the steps of:
A method for manufacturing an electro-optical device comprising the steps of:
A method for manufacturing an electro-optical device comprising the steps of:
Dependencies are inferred from the claim text.
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Constructional arrangements; Manufacturing methods: based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
Macromolecular compounds: as dispersing or encapsulating medium around the liquid crystal
Gaskets; Spacers; Sealing of cells: spacers dispersed on the cell substrate, e.g. spherical particles, microfibres
Active matrix addressed cells: in which the switching element is a three-electrode device
Term ended 6 Dec 2011 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
1. Field of the Invention
The present invention relates to a method for manufacturing an electro-optical device which can be readily scaled up into a large area. The electro-optical device according to the present invention is useful as a screen for shielding visual field of windows and show windows, as a light-control curtain, and as a liquid crystal display which displays and electrically converts characters, figures, symbols, and the like.
2. Description of the Prior Art
FIG. 1 is a cross sectional view of a liquid crystal electro-optical device according to the present invention;
FIG. 2 is a schematic view of a liquid crystal microcapsule used in a liquid crystal electro-optical device according to the present invention;
FIG. 3 is a graph showing the voltage-transmittance characteristic of a liquid crystal electro-optical device according to the present invention;
The present invention is described in further detail below referring to non-limiting examples.
Referring to FIG. 6, a first substrate having provided thereon an electric circuit is explained. On a first substrate 20 are established an N channel thin film transistor 2 and a P channel thin film transistor 3 at a complementary structure with respect to a pixel electrode 1 provided on the substrate. A source (drain) portion 4 of the P channel thin film transistor is connected to a first signal line 5 selected from a pair of signal lines, while a source (drain) portion 6 of the N channel thin film transistor is connected to a second signal line 7 of the pair of signal lines. Gate electrodes 8 and 9 of the N channel thin film transistor and the P channel transistor are connected to a common third signal line 10, and drain (source) portions 11 and 12 of the N channel thin film transistor and the P channel thin film transistor are connected to the pixel electrode 1. Thus is obtained an electric circuit on the first substrate as shown in FIG. 6.
After setting the first substrate above on a horizontal plane, isopropanol having dispersed or dissolved therein microcapsules of a nematic liquid crystal therein was distributed from an upper position on the surface of said first substrate. Now referring to FIG. 1, the liquid crystal electro-optical device according to an embodiment of the present invention is explained. The microcapsule of a nematic liquid crystal used herein comprises a nematic liquid crystal composition 14 and a coloring matter 15, e.g. a black dye, having encapsulated in a plastic spherical capsule (cover) 13 made of poly(vinyl alcohol) having an outer diameter of 2 .mu.m and an inner diameter of 1 .mu.m, which is further coated with a 2 .mu.m thick epoxy resin layer 16. On the surface of the epoxy resin layer is further scattered silica particles 17 from 100 to 200 .ANG. in diameter to improve higher dispersion in the solution. Spacers 22 can be dispersed in the layer together with the liquid crystal. In FIG. 2 is shown schematically the plastic capsule (cover) used in the present invention.