Patent US4425604A successfully refreshed from Google Patents.
US4425604A
Expired / Lapsed
US
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Illuminating device for a display unit
Assignee: Nissan Motor Co Ltd
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Filing: 1982-11-26
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Granted: 1984-01-10
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Expires: 2002-11-26
Abstract
Abstract An illuminating device for a display unit in which the display panel can be illuminated uniformly under a relatively constant luminous intensity. The illuminating device according to the present invention comprises a display panel, at least one light source and a reflector the inner surface of which is defined by at least two elliptical surfaces. One of two foci of each of the elliptical surfaces is located at the center of the light source and the other of two foci thereof is located on the inner surface of said display panel in order to focus rays of light reflected by the reflector on an area on the display panel away from the light source.
Inventors
- 👤 Hiroshi Imai
- 👤 Fukashi Sugasawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:14
CPC Classifications
F; F21; F21V; F21V7/00; F21V7/04; F21V7/08; G; G09; G09F; G09F13/00; G09F13/04; G09F13/14; F21W; F21W2111/00; G09F13/0418; G09F13/0422; G09F2013/145
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
130 words
An illuminating device for a display unit which comprises: (a) a display panel on which some letters or figures are displayed; (b) at least one light source disposed at the back of said display panel for illuminating said display panel; and (c) a reflector disposed at the back of said at least one light source, the inner surface of which is made up of at least two unit cells, the contours of each of which are defined by the union of a pair of parts of elliptical surfaces arranged in such a way that one of two foci of each of the elliptical surfaces is located at the center of said light source and the other of two foci thereof is located on the inner surface of said display unit.
Claim 2
Dependent Claim
130 words
An illuminating device for a display unit which comprises: (a) a display panel on which some letters or figures are displayed; (b) at least one light source disposed at the back of said display panel for illuminating said display panel; and (c) a reflector disposed at the back of said at least one light source, the inner surface of which is made up of at least two unit cells, the contours of each of which are defined by the union of a pair of parts of elliptical surfaces arranged in such a way that one of two foci of each of the elliptical surfaces is located at the center of said light source and the other of two foci thereof is located on the inner surface of said display unit.
Claim 3
Dependent Claim
133 words
An illuminating device for a display unit as set forth in claim 1, wherein in the case where a plurality of light sources are disposed at the back of said display panel, the inner surface of said reflector is defined by the contours of a plurality of parts of elliptical surfaces arranged in such a way that one of two foci of each of the two adjacent elliptical surfaces is located at the center of one of said two adjacent light sources and the other of two foci thereof is located approximately in the middle of said two adjacent light sources and on the inner surface of said display panel, the two long axes of said adjacent elliptical surfaces being alternately intersected at an angle near the inner surface of said display panel.
Claim 4
Dependent Claim
36 words
An illuminating device for a display unit as set forth in either claim 1 or 2, wherein in the case where said light source is a tubular light source, the elliptical surfaces are elliptical cylinder surfaces.
Claim 5
Dependent Claim
35 words
An illuminating device for a display unit as set forth in either claim 1 or 2, wherein in the case where said light source is a spherical light source, the elliptical surfaces are ellipsoidal surfaces.
Claim 6
Dependent Claim
22 words
An illuminating device for a display unit as set forth in claim 3, wherein said tubular light source is a fluorescent lamp.
Claim 7
Dependent Claim
22 words
An illuminating device for a display unit as set forth in claim 4, wherein said spherical light source is a bulb lamp.
Claim 8
Dependent Claim
26 words
An illuminating device for a display unit as set forth in either claim 1 or 2, wherein said display panel is a liquid crystal display panel.
Claim 9
Dependent Claim
25 words
An illuminating device for a display unit as set forth in either claim 1 or 2, wherein said display panel is an electrochromic display panel.
Claim 10
Dependent Claim
90 words
An illuminating device for a display unit which comprises: (a) a display panel on which some letters or figures are displayed; (b) at least one tubular light source disposed at the back of said display panel for illuminating said display panel; and (c) a reflector disposed at the back of said at least one light source, the inner surface of which is made up of at least two unit cells, the contours of each of which are defined by the union of a pair of parts right circular cylinder surfaces.
Claim 11
Dependent Claim
90 words
An illuminating device for a display unit which comprises: (a) a display panel on which some letters or figures are displayed; (b) at least one tubular light source disposed at the back of said display panel for illuminating said display panel; and (c) a reflector disposed at the back of said at least one light source, the inner surface of which is made up of at least two unit cells, the contours of each of which are defined by the union of a pair of parts right circular cylinder surfaces.
Claim 12
Dependent Claim
50 words
An illuminating device for a display unit as set forth in claim 9, wherein a plurality of light sources are disposed at the back of said display panel, and the inner surface of the reflector is defined by the contours of a plurality of parts of right circular cylinder surfaces.
Claim 13
Dependent Claim
90 words
An illuminating device for a display unit which comprises: (a) a display panel on which some letters or figures are displayed; (b) at least one tubular light source disposed at the back of said display panel for illuminating said display panel; and (c) a reflector disposed at the back of said at least one light source, the inner surface of which is made up of at least two unit cells, the contours of each of which are defined by the union of a pair of great numbers of flat surfaces.
Claim 14
Dependent Claim
90 words
An illuminating device for a display unit which comprises: (a) a display panel on which some letters or figures are displayed; (b) at least one tubular light source disposed at the back of said display panel for illuminating said display panel; and (c) a reflector disposed at the back of said at least one light source, the inner surface of which is made up of at least two unit cells, the contours of each of which are defined by the union of a pair of great numbers of flat surfaces.
Claim 15
Dependent Claim
49 words
An illuminating device for a display unit as set forth in claim 11, wherein a plurality of light sources are disposed at the back of said display panel, and the inner surface of said reflector is defined by the contours of a plurality of great numbers of flat surfaces.
Claim 16
Dependent Claim
89 words
An illuminating device for a display unit which comprises: (a) a display panel on which some letters or figures are displayed; (b) at least one spherical light source disposed at the back of said display panel for illuminating said display panel; and (c) a reflector disposed at the back of said at least one light source, the inner surface of which is made up of at least two unit cells, the contours of each of which are defined by the union of a pair of parts of spherical surfaces.
Claim 17
Dependent Claim
89 words
An illuminating device for a display unit which comprises: (a) a display panel on which some letters or figures are displayed; (b) at least one spherical light source disposed at the back of said display panel for illuminating said display panel; and (c) a reflector disposed at the back of said at least one light source, the inner surface of which is made up of at least two unit cells, the contours of each of which are defined by the union of a pair of parts of spherical surfaces.
Claim 18
Dependent Claim
48 words
An illuminating device for a display unit as set forth in claim 13, wherein a plurality of light sources are disposed at the back of said display panel, and the inner surface of said reflector is defined by the contours of a plurality of parts of spherical surfaces.
Claim 19
Dependent Claim
100 words
An illuminating device for a display unit which comprises: (a) a display panel on which some letters or figures are displayed; (b) at least one spherical light source disposed at the back of said display panel for illuminating said display panel; and (c) a reflector disposed at the back of said at least one light source, the inner surface of which is made up of at least two unit cells, the contours of each of which are defined by the union of a pair of parts of approximately elliptical surfaces, each surface defined by a great number of flat surfaces.
Claim 20
Dependent Claim
100 words
An illuminating device for a display unit which comprises: (a) a display panel on which some letters or figures are displayed; (b) at least one spherical light source disposed at the back of said display panel for illuminating said display panel; and (c) a reflector disposed at the back of said at least one light source, the inner surface of which is made up of at least two unit cells, the contours of each of which are defined by the union of a pair of parts of approximately elliptical surfaces, each surface defined by a great number of flat surfaces.
Claim 21
Dependent Claim
51 words
An illuminating device for a display unit as set forth in claim 15, wherein a plurality of spherical light sources are disposed at the back of said display panel, and the inner surface of said reflector is defined by the contours of a plurality of parts of said approximately elliptical surfaces.
References Cited (Backward Citations)
US4344111A
Cited
US4287554A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-01-09 | 1987-07-11 | 1988-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-09 | 1991-07-11 | 1992-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-09 | 1995-07-11 | 1996-01-10 | $7700.00 | Window Closed / Lapsed |