US4183075A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Illumination system for photographic enlargers
Assignee: Ernst Leitz Wetzlar GmbH
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Filing: 1978-04-17
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Granted: 1980-01-08
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Expires: 1998-04-17
Abstract
Abstract Illumination system for photographic enlargers having a chamber mounted between the lamp and the negative aperture and consisting of heat-insulating, non-staining material of high light reflective and scattering power. In addition to the light entry and exit apertures, a further opening has a wall-segment inserted therein for cooling the mixing chamber and this wall segment consists of a material having a greater heat conductivity than the polyalkene foam.
Inventors
- 👤 Alfred Hengst
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:47
CPC Classifications
G; G03; G03B; G03B27/00; G03B27/32; G03B27/52; G03B27/54; G03B27/545; G03B27/547
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
92 words
An illumination system for photographic enlargers having a lamp, a negative aperture and a light-mixing chamber mounted therebetween, said light-mixing chamber constructed from heat insulating, non-staining material of high light reflective and scattering power and having a front wall with a light entry aperture therein, a bottom wall with a light exit aperture therein and a rear wall with another aperture therein, said another aperture having a wall segment inserted therein for cooling said light-mixing chamber and said wall segment comprised of a material having a greater heat conductivity than said material.
Claim 2
Dependent Claim
92 words
An illumination system for photographic enlargers having a lamp, a negative aperture and a light-mixing chamber mounted therebetween, said light-mixing chamber constructed from heat insulating, non-staining material of high light reflective and scattering power and having a front wall with a light entry aperture therein, a bottom wall with a light exit aperture therein and a rear wall with another aperture therein, said another aperture having a wall segment inserted therein for cooling said light-mixing chamber and said wall segment comprised of a material having a greater heat conductivity than said material.
Claim 3
Dependent Claim
13 words
The illumination system of claim 1, wherein said wall-segment is made of metal.
Claim 4
Dependent Claim
21 words
The illumination system of claim 1, wherein said wall-segment is mounted at the area of incidence of the incoming light beams.
Claim 5
Dependent Claim
24 words
The illumination system of claim 1, wherein said wall-segment inserted into said another aperture extends over the entire side opposite said light entry aperture.
Claim 6
Dependent Claim
17 words
The illumination system of claim 1, wherein said wall-segment is provided with cooling fins on its outside.
Claim 7
Dependent Claim
19 words
The illumination system of claim 1, wherein said wall-segment is mounted in said another aperture using further insulating means.
Claim 8
Dependent Claim
17 words
The illumination system of claim 1, wherein the inside of said wall-segment comprises a diffusely reflecting surface.
Claim 9
Dependent Claim
16 words
The illumination system of claim 7, wherein said inside is coated with a white, matte lacquer.
Claim 10
Dependent Claim
15 words
The illumination system of claim 1, wherein the inside of said wall-segment is mirror coated.
Claim 11
Dependent Claim
30 words
The illumination system of claim 9, wherein the inside surface of said wall-segment is of such geometry and is so treated that its reflectivity corresponds to that of said material.
Claim 12
Dependent Claim
16 words
The illumination system of claim 1, wherein said material consists of polyalkene or substituted polyalkene foam.
References Cited (Backward Citations)
US3927941A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-01-07 | 1983-07-09 | 1984-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-01-07 | 1987-07-09 | 1988-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-01-07 | 1991-07-09 | 1992-01-08 | $7700.00 | Window Closed / Lapsed |