US3754823A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light source for color enlargers
Assignee: Berkey Photo Inc
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Filing: 1971-12-14
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Granted: 1973-08-28
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Expires: 1991-12-14
Abstract
Abstract In the photographic enlarging apparatus disclosed, three filters partially intercept a white light beam emerging from a light source having a reflector. The filters divide the beam into a white portion and an intensely colored portion. A mixing chamber mixes the white and intensely colored light. A diffuser at the bottom of the chamber illuminates a color film, either negative or positive slide. Optical means focus the light at the film onto printing paper. A light attenuator composed of a perforated metal plate is interposed between the source and the filters to dim the total light output of the enlarger. Mechanical means allow the attenuator to be shifted into and out of the beam. The face of the attenuator directed away from the source and toward the filters is provided with a reflecting surface. This reflecting surface prevents an undesirable color shift when the attenuator is moved into or out of the beam.
Inventors
- 👤 A Simmon
- 👤 L Weisglass
- 👤 R Flieder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 00:27
CPC Classifications
G; G03; G03B; G03B27/00; G03B27/72; G03B27/73
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
149 words
An illuminating system, comprising source means having a reflector for forming a light beam, filter means in the path of a portion of the beam for coloring a portion of the beam one color and reflecting another color back toward the source means, mixing chamber means having an opening in the path of the beam and opaque dispersing means for mixing the light of the beam entering said chamber means, said chamber means having an exit window for allowing egress of the light from said chamber means, diffusing means at said window for diffusing light as it leaves said chamber means, and attenuator means movable into and out of tHe beam at a location between said source means and said filter means, said attenuator means including an opaque plate forming a plurality of perforations, said opaque plate having a side facing said filter means, said side being substantially reflective.
Claim 2
Dependent Claim
149 words
An illuminating system, comprising source means having a reflector for forming a light beam, filter means in the path of a portion of the beam for coloring a portion of the beam one color and reflecting another color back toward the source means, mixing chamber means having an opening in the path of the beam and opaque dispersing means for mixing the light of the beam entering said chamber means, said chamber means having an exit window for allowing egress of the light from said chamber means, diffusing means at said window for diffusing light as it leaves said chamber means, and attenuator means movable into and out of tHe beam at a location between said source means and said filter means, said attenuator means including an opaque plate forming a plurality of perforations, said opaque plate having a side facing said filter means, said side being substantially reflective.
Claim 3
Dependent Claim
227 words
An enlarger, comprising a housing, source means having a reflector in said housing for forming a light means, filter means in said housing and in the path of a portion of the beam for coloring a portion of the beam one color and reflecting another color back toward the source means, mixing chamber means in said housing and having an opening in the path of the beam, said mixing chamber means having opaque dispersing means for mixing the light of the means beam entering said chamber means having an exit window for allowing egress of the light from said chamber means, a transparent diffusing plate in said housing and covering the window for diffusing light as it leaves said chamber means, film holder means adjacent said diffusing plate and in the path of light from said chamber means, optical means in said housing for focusing light passing through said film holder means, printing paper support means, mounting means for adjustably mounting said housing relative to said printing paper support means, and attenuator means in said housing, said attenuator means being movably mounted into and out of the path of the beam at a location between said source means and said filter means, said attenuator means including an opaque plate forming a plurality of perforations, said plate having a side facing said filter means, said side being reflective.
Claim 4
Dependent Claim
227 words
An enlarger, comprising a housing, source means having a reflector in said housing for forming a light means, filter means in said housing and in the path of a portion of the beam for coloring a portion of the beam one color and reflecting another color back toward the source means, mixing chamber means in said housing and having an opening in the path of the beam, said mixing chamber means having opaque dispersing means for mixing the light of the means beam entering said chamber means having an exit window for allowing egress of the light from said chamber means, a transparent diffusing plate in said housing and covering the window for diffusing light as it leaves said chamber means, film holder means adjacent said diffusing plate and in the path of light from said chamber means, optical means in said housing for focusing light passing through said film holder means, printing paper support means, mounting means for adjustably mounting said housing relative to said printing paper support means, and attenuator means in said housing, said attenuator means being movably mounted into and out of the path of the beam at a location between said source means and said filter means, said attenuator means including an opaque plate forming a plurality of perforations, said plate having a side facing said filter means, said side being reflective.
Claim 5
Dependent Claim
14 words
A system, as in claim 1, wherein said side is more reflective than absorbtive.
Claim 6
Dependent Claim
14 words
An enlarger, as in claim 2, wherein said side is more reflective than absorbtive.
Claim 7
Dependent Claim
11 words
A system, as in claim 1, wherein said side is mirrored.
Claim 8
Dependent Claim
11 words
An enlarger, as in claim 2, wherein said side is mirrored.
Claim 9
Dependent Claim
22 words
An apparatus,as in claim 1, wherein said plate has a second side facing said source means, said second side being substantially reflective.
Claim 10
Dependent Claim
23 words
An apparatus, as in claim 2, wherein said plate has a second side facing said source means, said second side being substantially reflective.
Claim 11
Dependent Claim
13 words
An apparatus, as in claim 7, wherein said reflective side is substantially mirrored.
Claim 12
Dependent Claim
12 words
An apparatus, as in claim 8, wherein said first side is mirrored.
Claim 13
Dependent Claim
14 words
An apparatus as in claim 1, wherein said filter means includes a dichroic filter.
Claim 14
Dependent Claim
14 words
An apparatus as in claim 2, wherein said filter means includes a dichroic filter.
Claim 15
Dependent Claim
14 words
An apparatus as in claim 3, wherein said filter means includes a dichroic filter.
Claim 16
Dependent Claim
14 words
An apparatus as in claim 4, wherein said filter means includes a dichroic filter.
Claim 17
Dependent Claim
14 words
An apparatus as in claim 5, wherein said filter means includes a dichroic filter.
Claim 18
Dependent Claim
14 words
An apparatus as in claim 6, wherein said filter means includes a dichroic filter.
Claim 19
Dependent Claim
14 words
An apparatus as in claim 7, wherein said filter means includes a dichroic filter.
Claim 20
Dependent Claim
14 words
An apparatus as in claim 8, wherein said filter means includes a dichroic filter.
Claim 21
Dependent Claim
14 words
An apparatus as in claim 9, wherein said filter means includes a dichroic filter.
Claim 22
Dependent Claim
14 words
An apparatus as in claim 10, wherein said filter means includes a dichroic filter.
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) | 1976-08-27 | 1977-02-26 | 1977-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-27 | 1981-02-26 | 1981-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-27 | 1985-02-26 | 1985-08-28 | $7700.00 | Window Closed / Lapsed |