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US4207671A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of manufacture of a passive electro-optic display cell having an helicoidal nematic liquid crystal and passive electro-optic display cell obtained by carrying out this method

Assignee: Ebauches SA
•
Filing: 1978-01-16
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Granted: 1980-06-17
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Expires: 1998-01-16
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Abstract

Abstract A liquid crystal alignment film is deposited on the inner surfaces of two plates of an electro-optic passive display cell. The film is vacuum evaporated on the plates at an incidence of 5° and at least one plate is rubbed in only the direction of deposition. A helicoidal nematic liquid crystal is disposed between the two plates of the cell, and is aligned by the film.

Inventors

  • 👤 Fereydoun Gharadjedaghi
  • 👤 Yves Ruedin
  • 👤 Rene Viennet

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 14:34
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1337; G02F1/133734; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 139 words
Method of manufacturing an electro-optic passive display cell including a helicoidal nematic liquid crystal disposed between two juxtaposed plates, said method comprising the steps of depositing an alignment film on an inner face of each of the two plates by vacuum evaporating the film material at an incidence of approximately 5° with respect to the plane of the plates, the deposited film having a direction of alignment on the plates which is the same as the direction of evaporation of the film projected on the plates, and rubbing the film deposited on at least one plate in one direction only, which direction is parallel to the direction of alignment of the film, whereby the molecules of the liquid crystal are oriented at an angle greater than 0° but less than 5° with respect to the plane of the plates.
Claim 2
Dependent Claim 139 words
Method of manufacturing an electro-optic passive display cell including a helicoidal nematic liquid crystal disposed between two juxtaposed plates, said method comprising the steps of depositing an alignment film on an inner face of each of the two plates by vacuum evaporating the film material at an incidence of approximately 5° with respect to the plane of the plates, the deposited film having a direction of alignment on the plates which is the same as the direction of evaporation of the film projected on the plates, and rubbing the film deposited on at least one plate in one direction only, which direction is parallel to the direction of alignment of the film, whereby the molecules of the liquid crystal are oriented at an angle greater than 0° but less than 5° with respect to the plane of the plates.
Claim 3
Dependent Claim 16 words
Method as claimed in claim 1, wherein the alignment film is silicon oxide, SiO x (1<×<2).
Claim 4
Dependent Claim 16 words
Method as claimed in claim 1, wherein the alignment film is magnesium floride, MgF 2 .
Claim 5
Dependent Claim 13 words
Method as claimed in claim 1, wherein the alignment film is platinium, Pt.
Claim 6
Dependent Claim 13 words
Method as claimed in claim 1, wherein the alignment film is chromium, Cr.
Claim 7
Dependent Claim 22 words
Method as claimed in claim 1, wherein the rubbing step is performed on the alignment film of each of the two plates.

References Cited (Backward Citations)

US3700306A Cited
US3930716A Cited
US3834792A Cited
US3963324A Cited
US3853391A Cited
US4084884A Cited
FR2268277A2 Cited
US3955881A Cited
US3966305A Cited
US4083099A Cited
US3967883A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1983-06-17 1983-12-17 1984-06-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1987-06-17 1987-12-17 1988-06-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1991-06-17 1991-12-17 1992-06-17 $7700.00 Window Closed / Lapsed

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