US3838565A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid crystal display utilizing ambient light for increased contrast
Assignee: American Microsystems Holding Corp
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Filing: 1973-06-21
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Granted: 1974-10-01
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Expires: 1993-06-21
Abstract
Abstract A readout display for use in combination with an electronic clock, calculator or electrical instrument utilizes a prism for receiving ambient light or light from a distant source and directing it through a louvered light film to back light and enhance the contrast characteristics of a liquid crystal display package. The latter is edge mounted in a base assembly including a printed circuit board for a display driver circuit and a power supply.
Inventors
- 👤 J Carlyle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:03
CPC Classifications
G; G04; G04G; G04G9/00; G04G9/08; G04G9/12; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G04G9/0023; G04G9/0029; G04G9/0035; G06; G06F; G06F15/00; G06F15/02; G06F15/0225
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
132 words
An electronic digital clock display comprising: a base unit forming a housing with a cavity; electrical circuit means located within said cavity; a liquid crystal display unit connected to said circuit means and extending upwardly from said base unit, said display unit including (a) a pair of spaced apart front and rear glass plates forming a planar cavity filled with nematic liquid crystal material, (b) a transparent film bonded to the outer surface of said rear plate having internal spaced apart louvers tilted downwardly within said film toward said rear plate, and (c) an optical prism having a first surface fixed to said film and a second surface forming an angle with said first surface for receiving ambient light that is reflected internally by the prism and directed toward said rear plate.
Claim 2
Dependent Claim
132 words
An electronic digital clock display comprising: a base unit forming a housing with a cavity; electrical circuit means located within said cavity; a liquid crystal display unit connected to said circuit means and extending upwardly from said base unit, said display unit including (a) a pair of spaced apart front and rear glass plates forming a planar cavity filled with nematic liquid crystal material, (b) a transparent film bonded to the outer surface of said rear plate having internal spaced apart louvers tilted downwardly within said film toward said rear plate, and (c) an optical prism having a first surface fixed to said film and a second surface forming an angle with said first surface for receiving ambient light that is reflected internally by the prism and directed toward said rear plate.
Claim 3
Dependent Claim
34 words
The digital clock display as described in claim 1 wherein said front plate of said display unit is longer than said rear plate and is edge mounted on and connected to said circuit means.
Claim 4
Dependent Claim
37 words
The digital clock display as described in claim 1 wherein said front plate of said display unit is substantially vertical and said second surface of said prism is substantially parallel to the bottom of said base unit.
Claim 5
Dependent Claim
57 words
The digital clock display as described in claim 1 wherein said circuit means comprises an elongated circuit board having a receptacle connector for receiving the lower edge of said front plate of said display unit and other electrical components for operating said clock display; and battery power means in said base unit connected to said circuit board.
Claim 6
Dependent Claim
37 words
A digital clock display as set forth in claim 1 wherein said transparent film layer is a plastic material with spaced apart microlouvers that are tilted downwardly toward said rear plate at an angle of about 30*.
Claim 7
Dependent Claim
37 words
A digital clock display as set forth in claim 2 wherein said transparent film layer is a plastic material with spaced apart microlouvers that are tilted downwardly toward said rear plate at an angle of about 30*.
Claim 8
Dependent Claim
37 words
A digital clock display as set forth in claim 3 wherein said transparent film layer is a plastic material with spaced apart microlouvers that are tilted downwardly toward said rear plate at an angle of about 30*.
Claim 9
Dependent Claim
37 words
A digital clock display as set forth in claim 4 wherein said transparent film layer is a plastic material with spaced apart microlouvers that are tilted downwardly toward said rear plate at an angle of about 30*.
References Cited (Backward Citations)
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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) | 1977-09-30 | 1978-04-01 | 1978-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-30 | 1982-04-01 | 1982-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-30 | 1986-04-01 | 1986-10-01 | $7700.00 | Window Closed / Lapsed |