US4760498A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photographic lamp
Assignee: Bron Elektronik AG
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Filing: 1986-10-02
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Granted: 1988-07-26
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Expires: 2006-10-02
Abstract
Abstract A photographic lamp possessing a main and back-reflector which are located respectively behind and in front of a light source. The main reflector limits a light exit aperture which is closed by a diffuser screen. The back-reflector comprises a transparent base which is partly provided with a reflecting layer. The reflecting layer is preferably applied in the manner of a graduated filter, so that the reflecting points are more numerous in the center of the base and less frequent at its periphery. The light produced is thereby extremely even and the illumination is very even, avoiding dark areas on the diffuser screen.
Inventors
- 👤 Joseph Lang
- 👤 Armin Nuessli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:57
CPC Classifications
F; F21; F21V; F21V7/00; G; G03; G03B; G03B27/00; G03B27/32; G03B27/52; G03B27/54; G03B27/542; F21W; F21W2131/00; F21W2131/40; F21W2131/406
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
78 words
A photographic lamp comprising: (a) a light source; (b) a main reflector located behind said light source with an exit aperture defined at the front end of said reflector; (c) a back-reflector located in front of said light source; and a diffuser screen covering the exit aperture of said main reflector, wherein said back-reflector comprises a light transparent base which is partly provided with a reflecting layer, said layer being applied with varying density onto said transparent base.
Claim 2
Dependent Claim
78 words
A photographic lamp comprising: (a) a light source; (b) a main reflector located behind said light source with an exit aperture defined at the front end of said reflector; (c) a back-reflector located in front of said light source; and a diffuser screen covering the exit aperture of said main reflector, wherein said back-reflector comprises a light transparent base which is partly provided with a reflecting layer, said layer being applied with varying density onto said transparent base.
Claim 3
Dependent Claim
49 words
The lamp as claimed in claim 1, wherein the density of said reflecting layer is at its greatest in the center of said back-reflector directly in front of said light source and said density decreases towards the periphery of said transparent base in the manner of a graduated filter.
Claim 4
Dependent Claim
17 words
The lamp as claimed in claim 1, wherein said reflecting layer comprises a thermally stable colored coating.
Claim 5
Dependent Claim
14 words
The lamp as claimed in claim 1, wherein said transparent base is a plate.
Claim 6
Dependent Claim
15 words
The lamp as claimed in claim 1, wherein said transparent base is made of glass.
Claim 7
Dependent Claim
14 words
The lamp as claimed in claim 2, wherein said transparent base is a plate.
Claim 8
Dependent Claim
83 words
A photographic lamp comprising: (a) a light source; (b) a main reflector located behind said light source with an exit aperture defined at the front end of said reflector; (c) a back-reflector located in front of said light source, and (d) a diffuser screen covering the exit aperture of said main reflector, wherein said back-reflector comprises a light transparent base which is partly provided with a reflecting layer, the density of said reflecting layer being proportional to the intensity of the incident light.
Claim 9
Dependent Claim
83 words
A photographic lamp comprising: (a) a light source; (b) a main reflector located behind said light source with an exit aperture defined at the front end of said reflector; (c) a back-reflector located in front of said light source, and (d) a diffuser screen covering the exit aperture of said main reflector, wherein said back-reflector comprises a light transparent base which is partly provided with a reflecting layer, the density of said reflecting layer being proportional to the intensity of the incident light.
Claim 10
Dependent Claim
79 words
A photographic lamp comprising: (a) a light source; (b) a main reflector located behind said light source with an exit aperture defined at the front end of said reflector; (c) a back-reflector located in front of said light source, and a diffuser screen covering the exit aperture of said main reflector, wherein said back-reflector comprises a light transparent base which is partly provided with a reflecting layer, said reflecting layer being applied in the form of dots and/or spots.
Claim 11
Dependent Claim
79 words
A photographic lamp comprising: (a) a light source; (b) a main reflector located behind said light source with an exit aperture defined at the front end of said reflector; (c) a back-reflector located in front of said light source, and a diffuser screen covering the exit aperture of said main reflector, wherein said back-reflector comprises a light transparent base which is partly provided with a reflecting layer, said reflecting layer being applied in the form of dots and/or spots.
Claim 12
Dependent Claim
125 words
A photographic lamp of the type having a back-reflector and a diffuser screen, comprising: (a) a light source; (b) a main reflector located behind said light source, said main reflector defining an exit aperture at the front thereof; (c) a back-reflector located in front of said light source, said back-reflector comprising a light-transparent base which is provided over at least one surface thereof with a reflecting layer, and (d) a diffuser screen in front of said back-reflector and covering said exit aperture, whereby light from said light source is both reflected back from said back-reflector to said main reflector and is passed through said transparent base; the result being that said diffuser screen is evenly illuminated and dark areas on the diffuser screen are eliminated.
Claim 13
Dependent Claim
125 words
A photographic lamp of the type having a back-reflector and a diffuser screen, comprising: (a) a light source; (b) a main reflector located behind said light source, said main reflector defining an exit aperture at the front thereof; (c) a back-reflector located in front of said light source, said back-reflector comprising a light-transparent base which is provided over at least one surface thereof with a reflecting layer, and (d) a diffuser screen in front of said back-reflector and covering said exit aperture, whereby light from said light source is both reflected back from said back-reflector to said main reflector and is passed through said transparent base; the result being that said diffuser screen is evenly illuminated and dark areas on the diffuser screen are eliminated.
Claim 14
Dependent Claim
30 words
The lamp as claimed in claim 9, wherein said reflecting layer comprises a thermally stable coating, the density of said coating being the greatest in the center of said back-reflector.
Claim 15
Dependent Claim
15 words
The lamp as claimed in claim 9, wherein said transparent base is made of glass.
Claim 16
Dependent Claim
14 words
The lamp as claimed in claim 9, wherein said transparent base is a plate.
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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) | 1991-07-26 | 1992-01-25 | 1992-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-26 | 1996-01-25 | 1996-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-26 | 2000-01-25 | 2000-07-26 | $7700.00 | Window Closed / Lapsed |