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US5355236A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of injecting ferroelectric liquid crystal including multiple pressure changes

Assignee: Canon Inc
•
Filing: 1993-05-05
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Granted: 1994-10-11
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Expires: 2013-05-05
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Abstract

Abstract A ferroelectric liquid crystal is injected into a liquid crystal cell including a pair of substrates each having at least an electrode thereon and disposed with a sealing agent therebetween so as to provide a prescribed gap therein. The liquid crystal is injected while (a) changing a pressure or a pressure and a temperature of an environment of the liquid crystal cell with time so that (i) in an initial stage of injection, the liquid crystal is injected at a suppressed speed, and (ii) in an intermediate stage of injection, the liquid crystal is injected at a controlled speed so that a front end of the liquid crystal injected within the cell progresses at a substantially constant speed, (b) in a final stage of injection, cooling the liquid crystal under a pressure so as to avoid occurrence of a local liquid crystal injection failure due to a difference in thermal expansion coefficient between the liquid crystal and the substrates, and (c) during the pressure-changing step with time, introducing an inert gas into the environment so as to increase the environmental pressure to a pressure exceeding a normal pressure (760 Torr).

Inventors

  • 👤 Mutsuo Mitsui

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 22:42
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1341; G02F1/137; G02F1/139; G02F1/141

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 184 words
A method of injecting a ferroelectric liquid crystal into a liquid crystal cell comprising a pair of substrates each having at least an electrode thereon and disposed with a sealing agent therebetween so as to provide a prescribed gap therebetween, the method comprising: (a) changing a pressure or a pressure and a temperature of an environment of the liquid crystal cell with time so that, in an initial stage of injection, the liquid crystal is injected at a suppressed speed, and in an intermediate stage of injection, the liquid crystal is injected at a controlled speed so that a front end of the liquid crystal injected within the cell progresses at a substantially constant speed, (b) in a final stage of injection, cooling the liquid crystal under a pressure so as to avoid occurrence of a local liquid crystal injection failure due to a difference in thermal expansion coefficient between the liquid crystal and the substrates, and (c) during the pressure-changing step with time, introducing an inert gas into the environment so as to increase the environmental pressure to a pressure exceeding 760 Torr.
Claim 2
Independent Claim 184 words
A method of injecting a ferroelectric liquid crystal into a liquid crystal cell comprising a pair of substrates each having at least an electrode thereon and disposed with a sealing agent therebetween so as to provide a prescribed gap therebetween, the method comprising: (a) changing a pressure or a pressure and a temperature of an environment of the liquid crystal cell with time so that, in an initial stage of injection, the liquid crystal is injected at a suppressed speed, and in an intermediate stage of injection, the liquid crystal is injected at a controlled speed so that a front end of the liquid crystal injected within the cell progresses at a substantially constant speed, (b) in a final stage of injection, cooling the liquid crystal under a pressure so as to avoid occurrence of a local liquid crystal injection failure due to a difference in thermal expansion coefficient between the liquid crystal and the substrates, and (c) during the pressure-changing step with time, introducing an inert gas into the environment so as to increase the environmental pressure to a pressure exceeding 760 Torr.
Claim 3
Dependent Claim 19 words
A method according to claim 1, wherein the pressure in the initial stage of injection is held substantially constant.
Claim 4
Dependent Claim 18 words
A method according to claim 1, wherein the pressure in the intermediate stage of injection is generally increased.
Claim 5
Dependent Claim 22 words
A method according to claim 3, wherein the pressure is held constant for a prescribed period during the intermediate stage of injection.
Claim 6
Dependent Claim 19 words
A method according to claim 1, wherein the pressure is held substantially constant in the final stage of injection.

References Cited (Backward Citations)

US4691995A Cited
JPS6431118A Cited
US5024255A Cited
EP0312028A2 Cited
US5285300A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-10-10 1998-04-11 1998-10-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-10-10 2002-04-11 2002-10-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-10-10 2006-04-11 2006-10-11 $7700.00 Window Closed / Lapsed

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