US3927941A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photographic enlarger mixing box
Assignee: Minolta Co Ltd
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Filing: 1974-06-28
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Granted: 1975-12-23
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Expires: 1994-06-28
Abstract
Abstract A photographic enlarger includes separably coupled vertically stacked sections including an upper light housing section, an intermediate filter box and a lower mixing box. The top and bottom of the filter box may correspond in transverse cross section to the confronting faces of the lamp housing and mixing box and have light entrance and exit parts. The filter box may be selected to contain different filter structures and mechanisms to adapt the enlarger for black and white and different color enlarging procedures. The mixing box is provided with light diffusing inner faces and mirror arrangements to increase the light intensity at the negative borders to effect uniform illumination of the negative.
Inventors
- 👤 Haruki Yamaguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:37
CPC Classifications
G; G03; G03B; G03B27/00; G03B27/72; G03B27/73
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
119 words
In a photographic enlarger having a light source and a filter box including filters and a mechanism for adjustment of said filters and a mixing box including an entrance for the light emerging from said filter box and a diffusing inside surface for mixing the light and an exit for mixed light, means for increasing the intensity of the light projected toward the peripheral area of said mixing box exit characterized in that said means for increasing the intensity of light comprises an inwardly facing reflecting surface disposed at the lower part of the inner periphery of said mixing box and said diffusing inside surface is disposed at the upper part of the inner periphery of said mixing box.
Claim 2
Dependent Claim
119 words
In a photographic enlarger having a light source and a filter box including filters and a mechanism for adjustment of said filters and a mixing box including an entrance for the light emerging from said filter box and a diffusing inside surface for mixing the light and an exit for mixed light, means for increasing the intensity of the light projected toward the peripheral area of said mixing box exit characterized in that said means for increasing the intensity of light comprises an inwardly facing reflecting surface disposed at the lower part of the inner periphery of said mixing box and said diffusing inside surface is disposed at the upper part of the inner periphery of said mixing box.
Claim 3
Dependent Claim
26 words
A photographic enlarger as in claim 1, wherein said inwardly facing reflecting surface is a mirror covering the lower part of said diffusing inner side surface.
Claim 4
Dependent Claim
26 words
A photographic enlarger as in claim 1 including reflecting means comprising an outwardly facing reflecting surface centrally disposed within the upper part of said mixing box.
Claim 5
Dependent Claim
30 words
A photographic enlarger as in claim 3, wherein said outwardly facing reflecting surface is a peripheral face of a cone centrally located within the upper part of said mixing box.
Claim 6
Dependent Claim
147 words
A photographic enlarger as in claim 1, wherein said mechanism for the adjustment of the filters comprises a plurality of combinations for independently adjusting the respective filters, each of said combinations including a member for supporting a filter for rotation between a first position with the filter fully registering with the light path and a second position with the filter completely out of registry with the light path and normally biased to said first position, said support member being provided with a cam edge elongated in a direction receding from the axis of rotation thereof, and a movable member contacting said cam edge at the remotest part thereof from said axis of rotation for setting said support member at said first position and further movable toward the axis of rotation for rotating said support member toward the second position by means of contact with said cam edge.
Claim 7
Dependent Claim
71 words
A photographic enlarger as in claim 5, further comprising a second movable member movable between a rest position and a position urging said support members of all of said combinations into said second positions thereof by means of engagement with openings respectively provIded in the support members, said openings being respectively arranged so as to allow the rotation of the support members with said second movable member in said rest position.
Claim 8
Dependent Claim
35 words
A photographic enlarger as in claim 1, wherein said light source, said filter box and said mixing box are respectively defined by three separate units, said three units being detachably combined to form the enlarger.
Claim 9
Dependent Claim
97 words
In a photographic enlarger having a light source and a filter box including filters and a mechanism for the adjustment thereof, a mixing box having an entrance for the light emerging from the filter box and a diffusing inside surface for mixing the light and an exit for the mixed light, wherein said mixing box comprises reflecting means for increasing the intensity of the light projected toward the peripheral areas of said mixing box exit and including a semi-sphere centrally located within the upper part of said mixing box and having an outwardly facing peripheral reflecting surface.
Claim 10
Dependent Claim
97 words
In a photographic enlarger having a light source and a filter box including filters and a mechanism for the adjustment thereof, a mixing box having an entrance for the light emerging from the filter box and a diffusing inside surface for mixing the light and an exit for the mixed light, wherein said mixing box comprises reflecting means for increasing the intensity of the light projected toward the peripheral areas of said mixing box exit and including a semi-sphere centrally located within the upper part of said mixing box and having an outwardly facing peripheral reflecting surface.
Claim 11
Dependent Claim
99 words
In a photographic enlarger having a light source and a filter box including filters and a mechanism for adjustment of said filters, a mixing box comprising: an entrance for the light emerging from said filter box; first inwardly facing means disposed under said entrance for diffusing the light incident thereon for mixture; an exit for the mixed light; and second inwardly facing means disposed between said first inwardly facing means and said exit for equi-angularly reflecting at least most of the light incident thereon for increasing the intensity of the light projected toward the peripheral area of said exit.
Claim 12
Dependent Claim
99 words
In a photographic enlarger having a light source and a filter box including filters and a mechanism for adjustment of said filters, a mixing box comprising: an entrance for the light emerging from said filter box; first inwardly facing means disposed under said entrance for diffusing the light incident thereon for mixture; an exit for the mixed light; and second inwardly facing means disposed between said first inwardly facing means and said exit for equi-angularly reflecting at least most of the light incident thereon for increasing the intensity of the light projected toward the peripheral area of said exit.
Claim 13
Dependent Claim
57 words
A mixing box as in claim 8 further comprising outwardly facing means disposed centrally within said mixing box and under said entrance for reflecting a part of the light passed said entrance toward said second inwardly facing means and permitting the other part of the light to directly impinge on said first and second inwardly facing means.
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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) | 1978-12-22 | 1979-06-23 | 1979-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-22 | 1983-06-23 | 1983-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-22 | 1987-06-23 | 1987-12-23 | $7700.00 | Window Closed / Lapsed |