US5030943A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Portable electroluminescent back light
Assignee: Fujitsu Personal Systems Inc
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Filing: 1988-11-23
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Granted: 1991-07-09
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Expires: 2008-11-23
Abstract
Abstract A back light for a liquid crystal display has a self-contained power source and can be attached to the unit having the liquid crystal display when needed in a dark ambient, and removed from the display or not carried by the user of the display when not needed. This portable back light allows the unit with the liquid crystal display to be smaller and lighter in weight than a unit having a built-in back light, and to require a smaller power supply than a unit with a built-in back light. Additinally batteries supplying power to a liquid crystal display unit will last longer. Yet with this portable back light, the user has the convenience of sufficient brightness for viewing the liquid crystal display unit when needed.
Inventors
- 👤 Noah L. Anglin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 03:25
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/1336; G02F1/133615; H; H05; H05B; H05B33/00; H05B33/12
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
67 words
For a liquid crystal display unit having a back panel through which light can penetrate and a front viewing surface which can be lighted by light which penetrates through said back panel, a back light which derives power from a renewable internal power source which does not power said liquid crystal display unit and which can be attached to and removed from said liquid crystal display unit.
Claim 2
Dependent Claim
67 words
For a liquid crystal display unit having a back panel through which light can penetrate and a front viewing surface which can be lighted by light which penetrates through said back panel, a back light which derives power from a renewable internal power source which does not power said liquid crystal display unit and which can be attached to and removed from said liquid crystal display unit.
Claim 3
Dependent Claim
30 words
A back light as in claim 1 comprising an electroluminescent panel, an internal power source, and a means for providing power from said internal power source to said electroluminescent panel.
Claim 4
Dependent Claim
21 words
A back light as in claim 2 further comprising a filter which controls the color of light from said electroluminescent panel.
Claim 5
Dependent Claim
49 words
A back light as in claim 2 further comprising a housing which holds said internal power source, said electroluminescent panel, and said means for providing power from said internal power source to said electroluminescent panel, and further includes means for attaching said housing to said liquid crystal display unit.
Claim 6
Dependent Claim
20 words
A back light as in claim 4 further comprising a mounting board which attaches said electroluminescent panel to said housing.
Claim 7
Dependent Claim
26 words
A back light as in claim 1 in which said power is supplied to said back light by means of a plug and a wall outlet.
Claim 8
Dependent Claim
28 words
A back light as in claim 2 in which said power source causes no increase in thickness of said back light unit beyond that required for providing light.
Claim 9
Dependent Claim
28 words
A back light as in claim 2 in which said power source causes no increase in width of said back light unit beyond that required for providing light.
References Cited (Backward Citations)
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Cited
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Cited
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Cited
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Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-07-08 | 1995-01-07 | 1995-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-08 | 1999-01-07 | 1999-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-08 | 2003-01-07 | 2003-07-09 | $7700.00 | Window Closed / Lapsed |