US4181756A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for increasing display brightness of liquid crystal displays by bleaching polarizers using screen-printing techniques
Assignee: Individual
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Filing: 1977-10-05
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Granted: 1980-01-01
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Expires: 1997-10-05
Abstract
Abstract Process and composition for selectively bleaching a polarizer, and particularly a polarizer used in a liquid crystal display, to achieve sharply-defined polarizing areas in accurate registration with the transparent conductive areas of the display. This is achieved by silk-screening a gel, containing a bleaching agent, onto selected areas of a polarizer in place of the display, the gel having a viscosity to permit silk-screening.
Inventors
- 👤 James L. Fergason
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:46
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/133528
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
55 words
A method for selectively bleaching sections of a planar polarizer comprising silk-screening onto selected areas of the polarizer a gel containing a substance which will bleach the polarizer dye, the gel having a consistency making it silk-screenable to form an accurate pattern with clearly-defined edges, and removing the gel after the dye has been bleached.
Claim 2
Independent Claim
55 words
A method for selectively bleaching sections of a planar polarizer comprising silk-screening onto selected areas of the polarizer a gel containing a substance which will bleach the polarizer dye, the gel having a consistency making it silk-screenable to form an accurate pattern with clearly-defined edges, and removing the gel after the dye has been bleached.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein said gel contains a gelatinous material selected from the group consisting of methylcarboxycellulose, AN-poly(methylvinyl ether/maleic anhydride), and carboxypolymethylene polymers.
Claim 4
Dependent Claim
32 words
The method of claim 2 wherein said polarizer is a polyvinyl alcohol iodine-based polarizer and said gel contains an alkali solution selected from the group consisting of potassium hydroxide and sodium hydroxide.
Claim 5
Dependent Claim
31 words
The method of claim 1 wherein said polarizer incorporates unsaturated dienes and said gel contains a chlorinating agent which will saturate the double-bonds of the dienes involved in the polarization process.
Claim 6
Dependent Claim
12 words
The method of claim 4 wherein said chlorinating agent comprises sodium hypochlorite.
Claim 7
Dependent Claim
92 words
The method of claim 1 wherein said planar polarizer is secured to the front transparent plate of a liquid crystal alpha-numeric display, the selected areas of the polarizer which are covered by the gel to bleach the same being those areas other than the areas of the polarizer registering with transparent conductive strips on the underside of the front transparent plate of the liquid crystal display, and including the step of registering the liquid crystal display exactly as it was registered in the formation of the transparent conductive strips prior to silk-screening.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-12-31 | 1983-07-02 | 1984-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-31 | 1987-07-02 | 1988-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-31 | 1991-07-02 | 1992-01-01 | $7700.00 | Window Closed / Lapsed |