US4766524A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Back light device for uniformly illuminating a liquid crystal display plate
Assignee: Hitachi Ltd
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Filing: 1987-02-09
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Granted: 1988-08-23
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Expires: 2007-02-09
Abstract
Abstract A back light device for uniformly illuminating a liquid crystal display plate comprises a fluorescent lamp having a luminous tube formed by being turned up through a coupling in the same plane, a liquid crystal display plate to be illuminated by the light radiated from the fluorescent lamp, a diffused plate interposed between the liquid crystal display plate and the fluorescent lamp in parallel to the plane, and a reflector for reflecting the light radiated from the fluorescent lamp toward the diffused plate.
Inventors
- 👤 Soichiro Ogawa
- 👤 Toshihiko Sano
- 👤 Takao Shimizu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 03:49
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/1336; G02F1/133602; G02F1/133604
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
102 words
A back light device for liquid crystal display comprising: a liquid crystal display plate having a substantially rectangular shape, a light source for illuminating the liquid crystal display plate and comprising a fluorescent lamp in the form of a tube and two base terminal sections, one connected to each end of the fluorescent tube, said two base terminal sections being located at one side beyond the periphery of the liquid crystal display plate, a diffusion plate interposed between the liquid crystal display plate and the fluorescent lamp, and a reflector for reflecting light radiated from the fluorescent lamp toward the diffusion plate.
Claim 2
Dependent Claim
102 words
A back light device for liquid crystal display comprising: a liquid crystal display plate having a substantially rectangular shape, a light source for illuminating the liquid crystal display plate and comprising a fluorescent lamp in the form of a tube and two base terminal sections, one connected to each end of the fluorescent tube, said two base terminal sections being located at one side beyond the periphery of the liquid crystal display plate, a diffusion plate interposed between the liquid crystal display plate and the fluorescent lamp, and a reflector for reflecting light radiated from the fluorescent lamp toward the diffusion plate.
Claim 3
Dependent Claim
29 words
A back light device for liquid crystal display according to claim 1, wherein a length of said fluorescent lamp tube is in contact with a surface of the reflector.
Claim 4
Dependent Claim
29 words
A back light device for liquid crystal display according to claim 1, wherein said fluorescent lamp includes two straight tubular sections which are interconnected by a curved tubular section.
Claim 5
Dependent Claim
19 words
A back light device for liquid crystal display according to claim 3, wherein said fluorescent lamp has a U-shape.
Claim 6
Dependent Claim
74 words
A back light device for liquid crystal display according to claim 3, wherein the two straight sections have parallel center axes separated by a distance l, the terminal sections of the lamp tube are located in a plane generally perpendicular to a width dimension D of said display plate as measured in a direction perpendicular to said center axes, and wherein the distance l and the width dimension D have the following relationship: 0.3<l/D<0.7.
Claim 7
Dependent Claim
21 words
A back light device for liquid crystal display according to claim 5, wherein the rate l/D is between 0.4 and 0.6.
Claim 8
Dependent Claim
30 words
A back light device for liquid crystal display according to claim 1, wherein the light source consists solely of a single fluorescent lamp tube having a single pair of terminals.
Claim 9
Dependent Claim
86 words
A back light device for liquid crystal display according to claim 7, wherein the single lamp tube includes two straight sections having generally parallel center axes separated by a distance l, the terminals for the tube lie in a side wall of a reflector box that lies in a plane generally perpendicular to a width dimension D of said display plate as measured in a direction perpendicular to said center axis, and wherein the distance M and the width dimension D have the following relationship: 0.3<l/D<0.7.
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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) | 1991-08-23 | 1992-02-22 | 1992-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-23 | 1996-02-22 | 1996-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-23 | 2000-02-22 | 2000-08-23 | $7700.00 | Window Closed / Lapsed |