US3846014A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid crystal display containing an additional broad angle back scattering material
Assignee: Northrop Grumman Guidance and Electronics Co Inc
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Filing: 1973-07-02
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Granted: 1974-11-05
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Expires: 1993-07-02
Abstract
Abstract A display is disclosed which contains a liquid crystal panel, a dichroic reflecting layer, and additionally contains a second wide angle back scattering material. Preferably, the second scattering material acts as a Lambertian scatterer. The display may include an external source of front-lighting, and, of course, contains suitable electrodes and substrates, and optionally contains anti-reflection coatings. The advantage of this display is that it is easily readable by an observer over a wide range of ambient lighting conditions. The outstanding readability is provided because the display has excellent color contrast.
Inventors
- 👤 R Aldrich
- 👤 W Simmons
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:30
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/133553
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
136 words
A DISPLAY WHICH IS ILLUMINATED BY AN EXTERNAL SOURCE OF FRONT LIGHTING, COMPRISING: A. A LAYER OF LIQUID CRYSTAL MATERIAL WHICH EXHIBITS DYNAMIC SCATTERING UPON APPLICATION OF AN ELECTRIC FIELD THEREACROSS, SAID LAYER BEING POSITIONED BETWEEN A FRONT TRANSPARENT ELECTRODE AND A BACK TRANSPARENT ELECTRODE; B. MEANS TO SELECTIVELY APPLYING AN ELECTRIC FIELD ACROSS DISCRETE AREAS OF SAID LAYER OF LIQUID CRYSTAL MATERIAL; C. A SCATTERING REFLECTOR WHICH SCATTERS REFLECTED LIGHT OVER A WIDE ANGLE, SAID REFLECTOR BEING POSITIONED BEHIND SAID BACK TRANSPARENT ELECTRODE; AND, D. A DICHROIC REFLECTING LAYER POSITIONED BETWEEN SAID SCATTERING REFLECTOR AND SAID LIQUID CRYSTAL MATERIAL, SAID DICHROIC REFLECTING LAYER HAVING THE CHARACTERISTIC OF REFLECTING ONE RANGE OF VISIBLE WAVELENGTHS FROM SAID EXTERNAL SOURCE OF FRONT LIGHTING AND TRANSMITTINGH A SECOND RANGE OF VISIBLE WAVELENGHTS FROM SAID EXTERNAL SOURCE OF FRONT LIGHTING.
Claim 2
Dependent Claim
136 words
A DISPLAY WHICH IS ILLUMINATED BY AN EXTERNAL SOURCE OF FRONT LIGHTING, COMPRISING: A. A LAYER OF LIQUID CRYSTAL MATERIAL WHICH EXHIBITS DYNAMIC SCATTERING UPON APPLICATION OF AN ELECTRIC FIELD THEREACROSS, SAID LAYER BEING POSITIONED BETWEEN A FRONT TRANSPARENT ELECTRODE AND A BACK TRANSPARENT ELECTRODE; B. MEANS TO SELECTIVELY APPLYING AN ELECTRIC FIELD ACROSS DISCRETE AREAS OF SAID LAYER OF LIQUID CRYSTAL MATERIAL; C. A SCATTERING REFLECTOR WHICH SCATTERS REFLECTED LIGHT OVER A WIDE ANGLE, SAID REFLECTOR BEING POSITIONED BEHIND SAID BACK TRANSPARENT ELECTRODE; AND, D. A DICHROIC REFLECTING LAYER POSITIONED BETWEEN SAID SCATTERING REFLECTOR AND SAID LIQUID CRYSTAL MATERIAL, SAID DICHROIC REFLECTING LAYER HAVING THE CHARACTERISTIC OF REFLECTING ONE RANGE OF VISIBLE WAVELENGTHS FROM SAID EXTERNAL SOURCE OF FRONT LIGHTING AND TRANSMITTINGH A SECOND RANGE OF VISIBLE WAVELENGHTS FROM SAID EXTERNAL SOURCE OF FRONT LIGHTING.
Claim 3
Dependent Claim
16 words
A display of claim 1 wherein said liquid crystal material comprises a nematic liquid crystal material.
Claim 4
Dependent Claim
14 words
A display of claim 2 wherein at least one of said electrodes is segmented.
Claim 5
Dependent Claim
13 words
A display of claim 3 wherein said scattering reflector comprises a Lambertian scatterer.
Claim 6
Dependent Claim
17 words
A display of claim 4 wherein said dichroic reflecting layer reflects green light and transmits red light.
Claim 7
Dependent Claim
17 words
A display of claim 4 wherein said dichroic reflecting layer reflects blue light and transmits yellow light.
Claim 8
Dependent Claim
33 words
A display of claim 4 wherein said nematic dynamic scattering liquid crystal material is selected from p-methoxybenzylidene-p-n-butylanaline; p-ethoxybenzylidene-p-n-butylanaline; p-butoxybenzylidene-p-n-BUTYLANALINE; p-aminophenyl acetate; trans4-butyl- Alpha -chloro-4''-ethoxystilbene; trans-4-octyl-Alpha -chloro-4''-ethoxystilbene; Licristal phase 5; and, Licristal phase 7a.
Claim 9
Dependent Claim
15 words
A display of claim 7 wherein said dichroic reflecting layer contains a transparent conductive layer.
Claim 10
Dependent Claim
13 words
A display of claim 1 wherein said scattering reflector comprises a Lambertian scatterer.
References Cited (Backward Citations)
US3756694A
Cited
US3748018A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-04 | 1978-05-06 | 1978-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-04 | 1982-05-06 | 1982-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-04 | 1986-05-06 | 1986-11-05 | $7700.00 | Window Closed / Lapsed |