US5123077A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light source device
Assignee: Hitachi Ltd
•
Filing: 1990-03-20
•
Granted: 1992-06-16
•
Expires: 2010-03-20
Abstract
Abstract The present invention relates to a light source device and particularly to a light source device which can be applied to a light source apparatus of a liquid crystal display apparatus which utilizes a flat plane type light source. The present invention provides a large size, light weight and thin flat plane light source which ensures uniform high level brightness to the entire part of display panel.
Inventors
- 👤 Syuusuke Endo
- 👤 Naofumi Aoyama
- 👤 Toshihiko Yabuuchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:54
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/0001; G02B6/0011; G02B6/0033; G02B6/0035; G02B6/0036; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; F; F21; F21V; F21V7/00; G02B6/0045; G02B6/0046; G02B6/24; G02B6/42; G02B6/4298; G09; G09F; G09F13/00; G09F13/04; G09F13/14; G09F13/0418; G09F13/0422; G09F2013/145; G09F13/18; G09F2013/1804; G09F2013/1827; Y; Y10; Y10S; Y10S385/00; Y10S385/901
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
132 words
A light source device comprising a light guiding element formed by a transparent medium having a particular refractive index and a pair of rod type light sources respectively arranged along two opposed end faces of the light guiding element; said light guiding element having a sectional view taken at right angles to said end faces, in which sectional view both end portions to which the light enters from said light sources are relatively thick, the center thereof is relatively thin and the bottom surface thereof is flat, while the surface opposite the bottom surface is a light emitting surface which is concave in a light emitting direction away from said bottom surface at a center region and convex in the light emitting direction in regions on either side of said center region.
Claim 2
Dependent Claim
132 words
A light source device comprising a light guiding element formed by a transparent medium having a particular refractive index and a pair of rod type light sources respectively arranged along two opposed end faces of the light guiding element; said light guiding element having a sectional view taken at right angles to said end faces, in which sectional view both end portions to which the light enters from said light sources are relatively thick, the center thereof is relatively thin and the bottom surface thereof is flat, while the surface opposite the bottom surface is a light emitting surface which is concave in a light emitting direction away from said bottom surface at a center region and convex in the light emitting direction in regions on either side of said center region.
Claim 3
Dependent Claim
54 words
A light source device according to claim 1, wherein part of said light emitting surface of said light guiding element has a fine roughness and the remaining part of said light emitting surface has a coarse roughness, said part having a fine roughness being located over at least a portion of said center region.
Claim 4
Dependent Claim
39 words
A light source device according to claim 2, wherein the degree of roughness in the light emitting surface of the light guiding element continuously changes from coarse roughness to fine roughness from the end faces toward the center thereof.
Claim 5
Dependent Claim
33 words
A light source device according to claim 2, wherein the bottom surface of said light guiding element has fine roughness in a central area thereof and a coarse roughness outside said central area.
Claim 6
Dependent Claim
40 words
A light source device according to claim 4, wherein the degree of roughness in the bottom surface of the light guiding element changes continuously from a fine roughness to a coarse roughness from the center thereof toward the end faces.
Claim 7
Dependent Claim
29 words
A light source device according to one of claims 1 to 5, wherein said rod type light source is arranged in plural at each end face of two sides.
Claim 8
Dependent Claim
33 words
A light source device according to claim 1, wherein the bottom surface of said light guiding element has fine roughness in a central area thereof and a coarse roughness outside said central area.
Claim 9
Dependent Claim
40 words
A light source device according to claim 7, wherein the degree of roughness in the bottom surface of the light guiding element changes continuously from a fine roughness to a coarse roughness from the center thereof toward the end faces.
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) | 1995-06-16 | 1995-12-16 | 1996-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-06-16 | 1999-12-16 | 2000-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-06-16 | 2003-12-16 | 2004-06-16 | $7700.00 | Window Closed / Lapsed |