Patent US5029045A successfully refreshed from Google Patents.
US5029045A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Surface lighting apparatus
Assignee: Mitsubishi Electric Corp
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Filing: 1989-08-04
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Granted: 1991-07-02
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Expires: 2009-08-04
Abstract
Abstract A surface lighting apparatus for backlighting a liquid crystal display panel(LCD) (4) has a light guide (11) for evenly illuminating back face of the LCD, the light guide comprising: an incidence plane wherefrom light beams from light source come in; a front face disposed vertical to the incidence plane wherefrom the light beams are out; and a curved back face whereon light reflecting layer is formed for reflecting the light beams to the front face.
Inventors
- 👤 Yukiharu Sanai
- 👤 Yuu Hirano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:52
CPC Classifications
G; G02; G02B; G02B27/00; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/1336; G02F1/133615; F; F21; F21V; F21V7/00; G01; G01D; G01D11/00; G01D11/28; G02B6/00; G02B6/0001; G02B6/0011; G02B6/0013; G02B6/0023; G02B6/0031; G02B6/0066; G02B6/0068; G02B6/0073; G02B6/0081; G02B6/0083; G02B6/0086; G02B6/0088; G09; G09F; G09F13/00; G09F13/18; G09F2013/1804; G09F2013/1831
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
117 words
A surface lighting apparatus comprising: light guiding means having an incidence plane, a back face having a gradually curved shape such that as the distance from said incidence plane increases the light incident angle to said back face increases, and a front face from which light beams are irradiated; diffusive-reflection means formed on said back face for diffusively reflecting light beams propagated from said incidence plane to said front face; at least one incandescent lamp having a lamp filament disposed perpendicularly to said incidence plane in the vicinity of said incidence plane; and reflection means formed in a trapezoidal shape enclosing said incandescent lamp for reflecting light beams irradiated from said incandescent lamp to said incidence plane.
Claim 2
Dependent Claim
117 words
A surface lighting apparatus comprising: light guiding means having an incidence plane, a back face having a gradually curved shape such that as the distance from said incidence plane increases the light incident angle to said back face increases, and a front face from which light beams are irradiated; diffusive-reflection means formed on said back face for diffusively reflecting light beams propagated from said incidence plane to said front face; at least one incandescent lamp having a lamp filament disposed perpendicularly to said incidence plane in the vicinity of said incidence plane; and reflection means formed in a trapezoidal shape enclosing said incandescent lamp for reflecting light beams irradiated from said incandescent lamp to said incidence plane.
Claim 3
Dependent Claim
30 words
A surface lighting apparatus in accordance with claim 1, wherein oblique edges of said trapezoidal shape of said reflection means have an angle of about 45° against said lamp filament.
Claim 4
Dependent Claim
19 words
A surface lighting apparatus in accordance with claim 2, wherein said reflection means also surrounds said light guiding means.
Claim 5
Dependent Claim
20 words
A surface lighting apparatus in accordance with claim 1, 2 or 3, wherein said reflection means is an aluminum plate.
Claim 6
Dependent Claim
19 words
A surface lighting apparatus in accordance with claim 4, wherein said reflection means is fixed on a printed substrate.
References Cited (Backward Citations)
US3040168A
Cited
US3349234A
Cited
US3729626A
Cited
US4487481A
Cited
US4460939A
Cited
JPS60140086A
Cited
US4648690A
Cited
US4729185A
Cited
US4630895A
Cited
US4714983A
Cited
JPS6269281A
Cited
US4933814A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-07-01 | 1994-12-31 | 1995-07-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-01 | 1998-12-31 | 1999-07-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-01 | 2002-12-31 | 2003-07-02 | $7700.00 | Window Closed / Lapsed |