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US4712876A Expired / Lapsed US ⏱️ 0.0 years remaining

Driving ferroelectric liquid crystal printers via short circuiting

Assignee: Hitachi Ltd
•
Filing: 1985-07-05
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Granted: 1987-12-15
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Expires: 2005-07-05
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Abstract

Abstract In a driving method of an optical switch element for controlling a quantity of transmission light between opposed electrodes by interposing a transparent, high dielectric material between the opposed electrodes and applying a positive or negative voltage between the opposed electrodes, the improvement wherein a period in which the opposed electrodes are substantially short-circuited is disposed in order to make it possible to either reduce or eliminate stored charge.

Inventors

  • 👤 Takao Umeda
  • 👤 Kazuya Ooishi
  • 👤 Tatsuo Igawa
  • 👤 Yasuro Hori

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 19:01
CPC Classifications
G; G02; G02F; G02F1/00; G06; G06K; G06K15/00; G06K15/02; G06K15/12; G06K15/1238; G06K15/1242; G06K15/1252; G02F1/01; G02F1/0121; G02F1/13; G02F1/133; G02F1/13306; Y; Y10; Y10S; Y10S359/00; Y10S359/90

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 229 words
A method for driving a plurality of optical switch elements of a liquid crystal device wherein each of the optical switch elements includes a transparent ferroelectric liquid crystal material between opposed electrodes, the method comprising the steps of applying a positive or negative voltage between the opposed electrodes of each of the plurality of optical switch elements selectively during a first period so as to control the quantity of transmission light between the opposed electrodes, and effecting a short circuit by simultaneously applying a substantially zero voltage between the opposed electrodes of all of the plurality of optical switch elements during a second period so as to reduce the quantity of non-uniform existence of ions in the high dielectric material between the opposed electrodes, wherein the second period is a period at least one of before and after the first period, and the second period is a shorter time than the first period and wherein the plurality of switch elements form part of a printer for printing a desired pattern on print regions of a paper having non-print regions, and the second period wherein the substantially zero voltage is applied simultaneously between opposed electrodes of all of the plurality of optical switch elements corresponds to at least one of the non-print regions at the leading and trailing end portions of the paper among the nonprint regions of the paper.
Claim 2
Independent Claim 229 words
A method for driving a plurality of optical switch elements of a liquid crystal device wherein each of the optical switch elements includes a transparent ferroelectric liquid crystal material between opposed electrodes, the method comprising the steps of applying a positive or negative voltage between the opposed electrodes of each of the plurality of optical switch elements selectively during a first period so as to control the quantity of transmission light between the opposed electrodes, and effecting a short circuit by simultaneously applying a substantially zero voltage between the opposed electrodes of all of the plurality of optical switch elements during a second period so as to reduce the quantity of non-uniform existence of ions in the high dielectric material between the opposed electrodes, wherein the second period is a period at least one of before and after the first period, and the second period is a shorter time than the first period and wherein the plurality of switch elements form part of a printer for printing a desired pattern on print regions of a paper having non-print regions, and the second period wherein the substantially zero voltage is applied simultaneously between opposed electrodes of all of the plurality of optical switch elements corresponds to at least one of the non-print regions at the leading and trailing end portions of the paper among the nonprint regions of the paper.
Claim 3
Dependent Claim 19 words
A method according to claim 1, wherein the second period is provided both before and after the first period.

References Cited (Backward Citations)

US3868674A Cited
US3961840A Cited
US4051465A Cited
US4429305A Cited
US4440473A Cited
US4508429A Cited
US4548476A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-12-14 1991-06-15 1991-12-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-12-14 1995-06-15 1995-12-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-12-14 1999-06-15 1999-12-15 $7700.00 Window Closed / Lapsed

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