US4039878A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric reflector lamp
Assignee: US Philips Corp
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Filing: 1976-10-06
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Granted: 1977-08-02
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Expires: 1996-10-06
Abstract
Abstract Electric reflector lamps having an ellipse-like curved reflector and a hyperbola-like curved IR reflector having a higher efficiency if not only the foci of both reflectors coincide and the high source is arranged on the coinciding foci present within the space enclosed by the reflectors, but the relationship a h = f × c 2 /a e also applies, where f is a factor dependent on the eccentricity of the ellipse.
Inventors
- 👤 Leonard Cornelis Hendrik Eijkelenboom
- 👤 Jan Antoon Henri Kesseler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:01
CPC Classifications
H; H01; H01K; H01K7/00; H01K7/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
199 words
An electric reflector lamp comprising (1) an ellipse-like curved total reflector, (2) a hyperbola-like curved, light-pervious, thermal radiation-reflecting reflector and (3) a light source in which the foci of the ellipse-like curved reflector coincide with those of the hyperbola-like curved reflector, the reflectors face each other with their concave sides, and the light source surrounds the coinciding foci situated within the space enclosed by the reflectors, characterized in that the ellipse-like curved reflector has an eccentricity c/a e of 0.5 to 0.99 and that the ellipse-like curved reflector and the hyperbola-like curved reflector satisfy the relationship a h = f × c 2 /a e , in which formula a h is half the distance between the branches of the hyperbola, a e is half the length of the long axis of the ellipse and c is half the focal distance of both the hyperbola and the ellipse according to which the reflectors are curved and f has a value between the limit values 0.84 and 1.14 if c/a e = 0.5, while f is between limit values nearer to 1.00 according as c/a e increases so that f is between 0.998 and 1.002 if c/a e = 0.99.
Claim 2
Dependent Claim
199 words
An electric reflector lamp comprising (1) an ellipse-like curved total reflector, (2) a hyperbola-like curved, light-pervious, thermal radiation-reflecting reflector and (3) a light source in which the foci of the ellipse-like curved reflector coincide with those of the hyperbola-like curved reflector, the reflectors face each other with their concave sides, and the light source surrounds the coinciding foci situated within the space enclosed by the reflectors, characterized in that the ellipse-like curved reflector has an eccentricity c/a e of 0.5 to 0.99 and that the ellipse-like curved reflector and the hyperbola-like curved reflector satisfy the relationship a h = f × c 2 /a e , in which formula a h is half the distance between the branches of the hyperbola, a e is half the length of the long axis of the ellipse and c is half the focal distance of both the hyperbola and the ellipse according to which the reflectors are curved and f has a value between the limit values 0.84 and 1.14 if c/a e = 0.5, while f is between limit values nearer to 1.00 according as c/a e increases so that f is between 0.998 and 1.002 if c/a e = 0.99.
Claim 3
Dependent Claim
16 words
An electric reflector as claimed in claim 1, characterized in that f has the value 1.
Claim 4
Dependent Claim
32 words
An electric reflector lamp as claimed in claim 1, characterized in that the ellipse-like and the hyperbola-like curved reflectors are both solids of revolution about the coinciding axes of ellipse and hyperbola.
Claim 5
Dependent Claim
19 words
An electric reflector lamp as claimed in claim 1, characterized in that the light source is an incandescent lamp.
Claim 6
Dependent Claim
31 words
An electric reflector lamp as claimed in claim 3, characterized in that the axis of symmetry of the filament has the same direction as the axis of symmetry of the reflector.
Claim 7
Dependent Claim
22 words
An electric reflector lamp as claimed in claim 4, characterized in that the reflectors constitute the lamp vessel of the incandescent lamp.
References Cited (Backward Citations)
US3494693A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-01 | 1981-01-31 | 1981-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-01 | 1985-01-31 | 1985-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-01 | 1989-01-31 | 1989-08-02 | $7700.00 | Window Closed / Lapsed |