US3704928A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dental light with dichroic and infrared filters
Assignee: GTE Sylvania Inc
•
Filing: 1970-11-09
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Granted: 1972-12-05
•
Expires: 1990-11-09
Abstract
Abstract A fixture for dental illumination, in which an elliptical reflector and light source is used with a light gate and projection lens, these being set in an enclosing canister with the light emerging through the lens, an infrared filter in the path of the light rays to absorb unwanted heat radiation, and a dichroic filter on the surface of the lens facing the reflector to correct the light-rendering index of the emitted light. Without any filter, neither infrared nor visible, the color rendering index of the light from the device is 97.5. When the infrared filter is added, this drops to 88.0, but the addition of the dichroic visible-light filter brings this back to 97.5, which is very good.
Inventors
- 👤 Peter M Coombs
- 👤 Ernest Davey
- 👤 Conrad Edward Kowalski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:47
CPC Classifications
F; F21; F21V; F21V9/00; F21V9/04; F21V7/00; F21V7/04; F21V7/08; F21V7/22; F21V9/08; G; G02; G02B; G02B6/00; G02B6/0001; G02B6/0005; F21W; F21W2131/00; F21W2131/20; F21W2131/202; Y; Y10; Y10S; Y10S362/00; Y10S362/804
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
129 words
A dental lighting fixture comprising: an optical system including an ellipsoidal reflector having a light source disposed at one focus thereof; a fixed light gate disposed in front of said optical system, said gate having a rectangular opening disposed at the other focus of said ellipsoidal reflector; a lens disposed in front of said light gate, said lens having a spheric side facing said light gate, the other side of said lens being aspheric; a dichroic coating disposed on said spheric side of said lens, said coating having higher transmission of blue light than of green, yellow, orange or red light; and an infrared absorbing glass filter disposed in front of said lens, the combination of said dichroic coating and said filter yielding light of high color rendering index.
Claim 2
Dependent Claim
129 words
A dental lighting fixture comprising: an optical system including an ellipsoidal reflector having a light source disposed at one focus thereof; a fixed light gate disposed in front of said optical system, said gate having a rectangular opening disposed at the other focus of said ellipsoidal reflector; a lens disposed in front of said light gate, said lens having a spheric side facing said light gate, the other side of said lens being aspheric; a dichroic coating disposed on said spheric side of said lens, said coating having higher transmission of blue light than of green, yellow, orange or red light; and an infrared absorbing glass filter disposed in front of said lens, the combination of said dichroic coating and said filter yielding light of high color rendering index.
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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) | 1975-12-05 | 1976-06-05 | 1976-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-05 | 1980-06-05 | 1980-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-05 | 1984-06-05 | 1984-12-05 | $7700.00 | Window Closed / Lapsed |