Patent US3335287A successfully refreshed from Google Patents.
US4730240A
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Reflector
Assignee: US Philips Corp
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Filing: 1982-12-06
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Granted: 1988-03-08
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Expires: 2002-12-06
Abstract
Abstract A reflector whose reflecting surface is formed as a portion of a solid of revolution, the generatrix of the solid of revolution having a plurality of staggered parabolic segments, the transition portions located between the segments changing smoothly into the segments and being of such a shape that in use in the reflector, of a light source, the reflected light beam has a comparatively large width and that the object to be illuminated is illuminated uniformly.
Inventors
- 👤 Franciscus A. M. M. van Meel
- 👤 Leonard C. H. Eijkelenboom
- 👤 Egbertus J. P. Maassen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:31
CPC Classifications
F; F21; F21V; F21V7/00; F21V7/04; F21V7/09; F21V7/06
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
185 words
A reflector in which an opening is present to accommodate a light source which reflector is formed as a portion of a solid of revolution, the generatrix of the solid of revolution being formed from a plurality of staggered parabolic segments, characterized in that the parabola axis associated with each parabolic segment P i makes a respective angle χ i (i=1, 2, 3 etc.) with the axis of revolution of the reflector, there being present at least between each pair of adjacent parabolic segments a respective transitional portion which smoothly changes into the adjoining parabolic segment(s), the generatrix of the reflector being of such a shape that χ.sub.i ≦ψ-0.5α.sub.min β≦0.75ψ, and 0.25α.sub.max ≦ψ≦2α.sub.max wherein α is the angle within which the ends of the light-emitting portion of the light source, when accommodated in the reflector, are seen from a point on the reflecting surface, and ψ is the half-value width of the light beam (in degrees) emerging from the reflector, β is the total change of inclination angle in the reflector, over that parabolic segment and adjoining transitional portion which provides the largest total change.
Claim 2
Dependent Claim
185 words
A reflector in which an opening is present to accommodate a light source which reflector is formed as a portion of a solid of revolution, the generatrix of the solid of revolution being formed from a plurality of staggered parabolic segments, characterized in that the parabola axis associated with each parabolic segment P i makes a respective angle χ i (i=1, 2, 3 etc.) with the axis of revolution of the reflector, there being present at least between each pair of adjacent parabolic segments a respective transitional portion which smoothly changes into the adjoining parabolic segment(s), the generatrix of the reflector being of such a shape that χ.sub.i ≦ψ-0.5α.sub.min β≦0.75ψ, and 0.25α.sub.max ≦ψ≦2α.sub.max wherein α is the angle within which the ends of the light-emitting portion of the light source, when accommodated in the reflector, are seen from a point on the reflecting surface, and ψ is the half-value width of the light beam (in degrees) emerging from the reflector, β is the total change of inclination angle in the reflector, over that parabolic segment and adjoining transitional portion which provides the largest total change.
Claim 3
Dependent Claim
34 words
A reflector as claimed in claim 1 wherein an additional transitional portion is included between the parabolic segment nearest the apex of the reflector and an opening in the apex for the light source.
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) | 1991-03-08 | 1991-09-07 | 1992-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-08 | 1995-09-07 | 1996-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-08 | 1999-09-07 | 2000-03-08 | $7700.00 | Window Closed / Lapsed |