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US4545648A Expired / Lapsed US ⏱️ 0.0 years remaining

Nacreous transflector illumination system for liquid crystal display

Assignee: 3M Innovative Properties Co
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Filing: 1980-10-30
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Granted: 1985-10-08
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Expires: 2000-10-30
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Abstract

Abstract An improved illumination system for electro-optical liquid crystal display devices comprising a nacreous transflector element capable of transmission as well as reflection of light so as to accommodate effective display illumination in conjunction with external and/or internal light sources for enhanced display viewability under all ambient lighting conditions.

Inventors

  • 👤 Joseph Shulman
  • 👤 David L. Clifford

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 00:56
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/133553; G02F1/133555; G02F2203/00; G02F2203/09

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 117 words
An electro-optical display device having an arrangement of front and rear light polarizers sandwiching front and rear optically-transmissive plates with a layer of a twisted nematic liquid crystal composition confined therebetween; means to impose a voltage between selected portions of said front and rear optically-transmissive plates and an illumination system comprising an internal light source positioned behind the rear optically-transmissive plate of the display and a nacreous transflector layer coated onto the back surface of said rear light polarizer, said nacreous transflector layer comprising a nacreous pigment material effective both to reflect light passing through said display from the front, as well as to transmit light into said display device emitted from the rear internal light source.
Claim 2
Dependent Claim 117 words
An electro-optical display device having an arrangement of front and rear light polarizers sandwiching front and rear optically-transmissive plates with a layer of a twisted nematic liquid crystal composition confined therebetween; means to impose a voltage between selected portions of said front and rear optically-transmissive plates and an illumination system comprising an internal light source positioned behind the rear optically-transmissive plate of the display and a nacreous transflector layer coated onto the back surface of said rear light polarizer, said nacreous transflector layer comprising a nacreous pigment material effective both to reflect light passing through said display from the front, as well as to transmit light into said display device emitted from the rear internal light source.
Claim 3
Dependent Claim 23 words
The electro-optical device of claim 1 wherein said nacreous transflector layer comprises a layer of nacreous pigment material dispersed in a binder medium.
Claim 4
Dependent Claim 13 words
The electro-optical display device of claim 2 wherein said binder is polyvinyl alcohol.
Claim 5
Dependent Claim 26 words
The electro-optical display device of claim 1 wherein said layer of nacreous pigment material has a coverage of about 2500 to about 7000 mg/ft 2 .
Claim 6
Dependent Claim 18 words
A transflector element comprising a layer of nacreous pigment material coated onto one surface of a light polarizer.
Claim 7
Dependent Claim 18 words
A transflector element comprising a layer of nacreous pigment material coated onto one surface of a light polarizer.
Claim 8
Dependent Claim 17 words
The transflector element of claim 5 wherin said nacreous pigment material is dispersed in a binder medium.
Claim 9
Dependent Claim 14 words
The transflector element of claim 5 where said nacreous pigment is titanium dioxide-coated mica.
Claim 10
Dependent Claim 24 words
The tranflector element of claim 5 wherein the nacreous pigment material has a coating coverage of about 2500 to about 7000 mg/ft 2 .
Claim 11
Dependent Claim 21 words
A transflector element comprising a layer of nacreous pigment material coated onto one surface of a polyvinyl alcohol-iodide complex light polarizer.
Claim 12
Dependent Claim 21 words
A transflector element comprising a layer of nacreous pigment material coated onto one surface of a polyvinyl alcohol-iodide complex light polarizer.
Claim 13
Dependent Claim 33 words
The transflector element of claim 9 wherein said light polarizer comprises a unidirectionally stretched, linearly oriented polyvinyl alcohol sheet, stained with a polyiodide solution, and supported on a sheet of cellulose acetate butyrate.
Claim 14
Dependent Claim 20 words
The transflector element of claim 4 wherein said nacreous pigment material is dispersed in a binder medium of polyvinyl alcohol.

References Cited (Backward Citations)

US3219734A Cited
US3857628A Cited
US4025688A Cited
US4126383A Cited
US4096550A Cited
US4151666A Cited
US4196973A Cited
US4355868A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1988-10-07 1989-04-08 1989-10-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1992-10-07 1993-04-08 1993-10-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1996-10-07 1997-04-08 1997-10-08 $7700.00 Window Closed / Lapsed

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