US5132823A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multipurpose liquid crystal display having means for removably positioning the retroreflector
Assignee: Raychem Corp
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Filing: 1991-08-30
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Granted: 1992-07-21
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Expires: 2011-08-30
Abstract
Abstract A multipurpose liquid crystal display, suitable for use as a reflective display and as overhead projection panel, includes (a) a first transparent electrode means; (b) a second transparent electrode means; (c) a display medium positioned between the first and second transparent electrode means, which display medium is switchable between a first state in which incident light is scattered and a second state in which the amount of such scattering is reduced; (d) a retroreflector removably positioned behind the second transparent electrode means; and (e) means for removably positioning the retroreflector behind the second transparent electrode. Preferably, the display medium comprises positive dielectric anisotropy, operationally nematic liquid crystals dispersed in a containment medium.
Inventors
- 👤 Hundi Kamath
- 👤 Philip J. Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:02
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/133553; G02B; G02B5/00; G02B5/12; G02B5/122; G02B5/124; G02F1/1334
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
95 words
A multipurpose liquid crystal display suitable for use as a reflective display and as overhead projection panel, comprising (a) a first transparent electrode means; (b) a second transparent electrode means; (c) a display medium positioned between the first and second transparent electrode means, which display medium is switchable between a first state in which incident light is scattered and a second state in which the amount of such scattering is reduced; (d) a retroreflector removably positioned behind the second transparent electrode means; and (e) means for removably positioning the retroreflector behind the second transparent electrode.
Claim 2
Dependent Claim
95 words
A multipurpose liquid crystal display suitable for use as a reflective display and as overhead projection panel, comprising (a) a first transparent electrode means; (b) a second transparent electrode means; (c) a display medium positioned between the first and second transparent electrode means, which display medium is switchable between a first state in which incident light is scattered and a second state in which the amount of such scattering is reduced; (d) a retroreflector removably positioned behind the second transparent electrode means; and (e) means for removably positioning the retroreflector behind the second transparent electrode.
Claim 3
Dependent Claim
28 words
A display according to claim 1, wherein the means for removably positioning the retroreflector is a bracket having a slot means for sliding the retroreflector in and out.
Claim 4
Dependent Claim
39 words
A display according to claim 1, wherein the means for removably positioning the retroreflector is a bracket having a hinge to which the retroreflector is affixed and via which the retroreflector can be pivoted in and out of position.
Claim 5
Dependent Claim
20 words
A display according to claim 1, wherein the retroreflector is toollessly removable its position behind the second transparent electrode means.
Claim 6
Dependent Claim
26 words
A display according to claim 1, wherein the pixel pitch in the display medium is greater than the pitch of the retroreflective elements in the retroreflector.
Claim 7
Dependent Claim
39 words
A display according to claim 1, wherein the retroreflector comprises an array of full corner cube elements and has an optic axis tilted towards the top of the display by an angle of between about 10° and about 45°.
Claim 8
Dependent Claim
22 words
A display according to claim 6, wherein the optic axis of the retroreflector is tilted by between about 10° and about 20°.
Claim 9
Dependent Claim
22 words
A display according to claim 6, wherein the optic axis of the retroreflector is tilted by between about 30° and about 20°.
Claim 10
Dependent Claim
21 words
A display according to claim 6, wherein the retroreflector is a front surface retroreflector whose corner cube elements are specularly reflective.
Claim 11
Dependent Claim
23 words
A display according to claim 6, wherein the retroreflector is a rear surface retroreflector whose corner cube elements reflect by total internal reflection.
Claim 12
Dependent Claim
21 words
A display according to claim 6, wherein the retroreflector is a rear surface retroreflector whose corner cube elements are specularly reflective.
Claim 13
Dependent Claim
45 words
A display according to claim 6, wherein the retroreflector comprises a front half which is a rear surface retroreflector whose corner cube elements reflect by total internal reflection and a rear half which is a front surface retroreflector whose corner cube elements are specularly reflective.
Claim 14
Dependent Claim
40 words
A display according to claim 6, wherein in the corner cube elements the intersection of an orthogonal face of one corner cube element with an orthogonal face of another corner cube element are masked with a dark, light absorbing material.
Claim 15
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 16
Dependent Claim
28 words
A display according to claim 14, wherein the means for removably positioning the retroreflector is a bracket having a slot means for sliding the retroreflector in and out.
Claim 17
Dependent Claim
39 words
A display according to claim 14, wherein the means for removably positioning the retroreflector is a bracket having a hinge to which the retroreflector is affixed and via which the retroreflector can be pivoted in and out of position.
Claim 18
Dependent Claim
20 words
A display according to claim 14, wherein the retroreflector is toollessly removable its position behind the second transparent electrode means.
Claim 19
Dependent Claim
26 words
A display according to claim 14, wherein the pixel pitch in the display medium is greater than the pitch of the retroreflective elements in the retroreflector.
Claim 20
Dependent Claim
22 words
A display according to claim 14, wherein the optic axis of the retroreflector is tilted by between about 10° and about 20°.
Claim 21
Dependent Claim
22 words
A display according to claim 14, wherein the optic axis of the retroreflector is tilted by between about 30° and about 45°.
Claim 22
Dependent Claim
21 words
A display according to claim 14, wherein the retroreflector is a front surface retroreflector whose corner cube elements are specularly reflective.
Claim 23
Dependent Claim
23 words
A display according to claim 14, wherein the retroreflector is a rear surface retroreflector whose corner cube elements reflect by total internal reflection.
Claim 24
Dependent Claim
21 words
A display according to claim 14, wherein the retroreflector is a rear surface retroreflector whose corner cube elements are specularly reflective.
Claim 25
Dependent Claim
45 words
A display according to claim 14, wherein the retroreflector comprises a front half which is a rear surface retroreflector whose corner cube elements reflect by total internal reflection and a rear half which is a front surface retroreflector whose corner cube elements are specularly reflective.
Claim 26
Dependent Claim
40 words
A display according to claim 14, wherein in the corner cube elements the intersection of an orthogonal face of one corner cube element with an orthogonal face of another corner cube element are masked with a dark, light absorbing material.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-07-21 | 1996-01-20 | 1996-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-07-21 | 2000-01-20 | 2000-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-07-21 | 2004-01-20 | 2004-07-21 | $7700.00 | Window Closed / Lapsed |