US4227804A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Illuminating apparatus with a light control channel for photographic enlarging equipment with a rotatable picture stage in the plane of the negative to be copied
Assignee: Durst Group AG
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Filing: 1979-03-26
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Granted: 1980-10-14
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Expires: 1999-03-26
Abstract
Abstract An illuminating system for use in a photographic enlarging apparatus having first and second light control channels is disclosed. The light control channels receive and transmit light from a light source; the light exit end of the first light control channel has a diagonal that is less than the longest side of the cross-section of the light entrance end of the second light control channel. A picture stage for receiving and supporting a negative to be projected is secured to the light exit end of the second light control channel. The second light control channel and the picture stage are mounted for unitary rotational movement about an axis normal to the plane of the negative.
Inventors
- 👤 Wilhelm Pramstraller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 02:19
CPC Classifications
G; G03; G03B; G03B27/00; G03B27/32; G03B27/52; G03B27/54; G03B27/545
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
60 words
In a photographic enlarging apparatus having a light source and a rotatable picture stage for receiving and supporting a negative to be projected, the improvement comprising: means comprising a light control channel positioned on the light entrance side of said picture stage and secured to said stage for rotation therewith about an axis normal to the plane of said negative.
Claim 2
Dependent Claim
60 words
In a photographic enlarging apparatus having a light source and a rotatable picture stage for receiving and supporting a negative to be projected, the improvement comprising: means comprising a light control channel positioned on the light entrance side of said picture stage and secured to said stage for rotation therewith about an axis normal to the plane of said negative.
Claim 3
Dependent Claim
19 words
The improvement set forth in claim 1 wherein said picture stage is removably secured to said light control channel.
Claim 4
Dependent Claim
21 words
The improvement set forth in claim 1 or 2 wherein said light control channel is detachably secured to said enlarging apparatus.
Claim 5
Dependent Claim
43 words
The improvement set forth in claim 3 wherein said apparatus includes a mounting plate having a circular depression therein, and wherein said picture stage includes raised portions extending into said depression to provide support for said picture stage and permit the rotation thereof.
Claim 6
Dependent Claim
47 words
The improvement set forth in claim 4 wherein said picture stage is formed of an upper portion detachably secured to said light control channel, and a lower portion removably supported by said mounting plate, and wherein said upper and lower portions are hingedly secured to each other.
Claim 7
Dependent Claim
121 words
In a photographic enlarging apparatus having a light source and a rotatable picture stage for receiving and supporting a negative to be projected, the improvement comprising: a first light control channel for receiving and directing light from said light source; a second light control channel mounted to receive light from said first light control channel, the diagonal of the cross-section of the light exit end of said first light control channel being shorter than the longest side length of the cross-section of the light entrance end of the second light control channel; the light exit end of said second light control channel being secured to said picture stage for rotation therewith about an axis normal to the plane of said negative.
Claim 8
Dependent Claim
121 words
In a photographic enlarging apparatus having a light source and a rotatable picture stage for receiving and supporting a negative to be projected, the improvement comprising: a first light control channel for receiving and directing light from said light source; a second light control channel mounted to receive light from said first light control channel, the diagonal of the cross-section of the light exit end of said first light control channel being shorter than the longest side length of the cross-section of the light entrance end of the second light control channel; the light exit end of said second light control channel being secured to said picture stage for rotation therewith about an axis normal to the plane of said negative.
Claim 9
Dependent Claim
20 words
The improvement set forth in claim 6 wherein said picture stage is removably secured to said second light control channel.
Claim 10
Dependent Claim
22 words
The improvement set forth in claims 6 or 7 wherein said second light control channel is detachably secured to said enlarging apparatus.
Claim 11
Dependent Claim
45 words
The improvement set forth in claim 6 or 7 wherein said apparatus includes a mounting plate having a circular depression therein and wherein said picture stage includes raised portions extending into said depression to provide support for said picture stage and permit the rotation thereof.
Claim 12
Dependent Claim
48 words
The improvement set forth in claim 9 wherein said picture stage is formed of an upper portion detachably secured to said second light control channel, and a lower portion removably supported by said mounting plate, and wherein said upper and lower portions are hingedly secured to each other.
Claim 13
Dependent Claim
99 words
In a photographic enlarging apparatus having a light source and a rotatable picture stage for receiving and supporting a negative to be projected, the improvement comprising a light control channel positioned on the light entrance side of said picture stage, the light exit end of said light control channel having a cross-section matching the area of said negative to be projected, said light control channel being secured to said picture stage for rotation therewith wherein the light exit end of said light control channel is maintained in alignment with said negative irregardless of the orientation of said picture stage.
Claim 14
Dependent Claim
99 words
In a photographic enlarging apparatus having a light source and a rotatable picture stage for receiving and supporting a negative to be projected, the improvement comprising a light control channel positioned on the light entrance side of said picture stage, the light exit end of said light control channel having a cross-section matching the area of said negative to be projected, said light control channel being secured to said picture stage for rotation therewith wherein the light exit end of said light control channel is maintained in alignment with said negative irregardless of the orientation of said picture stage.
Claim 15
Dependent Claim
19 words
The improvement set forth in claim 11 wherein said picture stage is removably secured to said light control channel.
Claim 16
Dependent Claim
43 words
The improvement set forth in claim 12 wherein said apparatus includes a mounting plate having a circular depression therein, and wherein said picture stage includes raised portions extending into said depression to provide support for said picture stage and permit the rotation thereof.
Claim 17
Dependent Claim
47 words
The improvement set forth in claim 13 wherein said picture stage is formed of an upper portion detachably secured to said light control channel, and a lower portion removably supported by said mounting plate, and wherein said upper and lower portions are hingedly secured to each other.
Claim 18
Dependent Claim
19 words
The improvement set forth in claim 11 wherein said light control channel is detachably secured to said enlarging apparatus.
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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) | 1983-10-14 | 1984-04-14 | 1984-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-14 | 1988-04-14 | 1988-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-14 | 1992-04-14 | 1992-10-14 | $7700.00 | Window Closed / Lapsed |