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US5138472A Expired / Lapsed US ⏱️ 0.0 years remaining

Display having light scattering centers

Assignee: Tyco International Ltd Bermuda
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Filing: 1991-02-11
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Granted: 1992-08-11
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Expires: 2011-02-11
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Abstract

Abstract A display having (a) a first electrode; (b) a second electrode; (c) a display medium positioned between the first and second electrodes, which display medium is switchable between a first state in which incident light is at least one of scattered and absorbed and a second state in which the amount of such scattering and/or absorption is reduced; and (d) scattering centers disposed in front of the second electrode for scattering incident light with a scattering half angle of between about 2 and about 40 degrees when the display medium is in its second state, while permitting at least 10% of the incident light to be transmitted.

Inventors

  • 👤 Philip J. Jones
  • 👤 Akira Tomita
  • 👤 Mark F. Wartenberg

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 15:43
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1334; G02F1/137; G02F1/13706; G02F2202/00; G02F2202/04; G02F2202/043; G02F2203/00; G02F2203/03

Claims Analysis

Total Claims: 17
Claim 1
Independent Claim 100 words
A display comprising: a first electrode means; a second electrode means; a display medium positioned between the first and second electrode means, which display medium is switchable between a first state in which incident light is at least one of scattered and absorbed and a second state in which the amount of such scattering and/or absorption is reduced; and plural scattering centers for scattering incident light with a scattering half angle of between about 2 and about 40 degrees when the display medium is in its second state, while permitting at least 10% of the incident light to be transmitted.
Claim 2
Dependent Claim 100 words
A display comprising: a first electrode means; a second electrode means; a display medium positioned between the first and second electrode means, which display medium is switchable between a first state in which incident light is at least one of scattered and absorbed and a second state in which the amount of such scattering and/or absorption is reduced; and plural scattering centers for scattering incident light with a scattering half angle of between about 2 and about 40 degrees when the display medium is in its second state, while permitting at least 10% of the incident light to be transmitted.
Claim 3
Dependent Claim 23 words
A display according to claim 1, wherein the display medium comprises positive dielectric anisotropy, operationally nematic liquid crystals dispersed in a containment medium.
Claim 4
Dependent Claim 14 words
A display according to claim 2, wherein the liquid crystals contain a pleochroic dye.
Claim 5
Dependent Claim 27 words
A display according to claim 1, 2, or 3, wherein the scattering centers are disposed in a layer between the display medium and the second electrode means.
Claim 6
Dependent Claim 26 words
A display according to claim 4, wherein the second electrode means is reflective, for reflecting light passing through the display medium back through the display medium.
Claim 7
Dependent Claim 13 words
A display according to claim 4, wherein the second electrode means is transparent.
Claim 8
Dependent Claim 26 words
A display according to claim 4, wherein the scattering centers are selected from the group consisting of titanium dioxide, alumina, and other metal oxides; and silica.
Claim 9
Dependent Claim 18 words
A display according to claim 2 or 3, wherein the scattering centers are dispersed in the containment medium.
Claim 10
Dependent Claim 26 words
A display according to claim 8, wherein the second electrode means is reflective, for reflecting light passing through the display medium back through the display medium.
Claim 11
Dependent Claim 13 words
A display according to claim 8, wherein the second electrode means is transparent.
Claim 12
Dependent Claim 59 words
A display according to claim 6, wherein the scattering centers are selected from the group consisting of particles of titanium dioxide, alumina, and other metal oxides; silica particles; hollow spheres; glass beads; gas bubbles; silicone oil droplets, smectic liquid crystal droplets, droplets of operationally nematic liquid crystal having a negative dielectric anisotropy; latex particles; and cholesteric liquid crystal droplets.
Claim 13
Dependent Claim 106 words
A liquid crystal display medium switchable between a first state in which incident light is at least one of scattered and absorbed and a second state in which the amount of such scattering and/or absorption is reduced in the presence of a sufficient electric field, comprising: a containment medium; discrete volumes of liquid crystals dispersed in the containment medium; and plural scattering centers dispersed in the containment medium for scattering incident light with a scattering half angle of between about 2 and about 40 degrees when the display medium is in its second state, while permitting at least 10% of the incident light to be transmitted.
Claim 14
Dependent Claim 106 words
A liquid crystal display medium switchable between a first state in which incident light is at least one of scattered and absorbed and a second state in which the amount of such scattering and/or absorption is reduced in the presence of a sufficient electric field, comprising: a containment medium; discrete volumes of liquid crystals dispersed in the containment medium; and plural scattering centers dispersed in the containment medium for scattering incident light with a scattering half angle of between about 2 and about 40 degrees when the display medium is in its second state, while permitting at least 10% of the incident light to be transmitted.
Claim 15
Dependent Claim 21 words
A liquid crystal display medium according to claim 12, wherein the liquid crystals are positive dielectric anisotropy, operationally nematic liquid crystals.
Claim 16
Dependent Claim 17 words
A liquid crystal display medium according to claim 13, wherein the liquid crystals contain a pleochroic dye.
Claim 17
Dependent Claim 65 words
A liquid crystal display medium according to claim 12, 13, or 14, wherein the scattering centers are selected from the group consisting of particles of titanium dioxide, alumina, and other metal oxides; silica particles; hollow spheres; glass beads; gas bubbles; silicone oil droplets, smectic liquid crystal droplets, droplets of operationally nematic liquid crystal having a negative dielectric anisotropy; latex particles; and cholesteric liquid crystal droplets.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-08-11 1996-02-10 1996-08-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-08-11 2000-02-10 2000-08-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-08-11 2004-02-10 2004-08-11 $7700.00 Window Closed / Lapsed

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