US3648019A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Developer
Assignee: 3M Co
•
Filing: 1971-01-04
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Granted: 1972-03-07
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Expires: 1991-01-04
Abstract
Abstract A simple and portable developer for a sheet of heat developable paper or film. The developer includes a pair of heaters mounted in parallel opposed relationship to define a heated zone and to provide a generally uniform temperature gradient within the heated zone. A support member is mounted for supporting a sheet at an essentially constant temperature level within the heated zone to develop the sheet in a predetermined time. Two halves of the developer are separable to afford insertion and removal of the sheet.
Inventors
- 👤 Frederick G Brewitz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:02
CPC Classifications
G; G03; G03D; G03D15/00; G03D15/02; G03D15/027; G03D13/00; G03D13/002
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
146 words
A developer for developing a sheet of heat developable material comprising: a housing having wall portions; a pair of planar heaters mounted in said housing in opposed generally parallel relationship for defining a shallow heated zone within said housing for producing essentially a uniform temperature gradient in said heated zone between said heaters; insulating material disposed between said heaters and the adjacent wall portions; planar locating means mounted generally centrally within said heated zone for positioning a said sheet of heat developable material generally parallel to said heaters within said heated zone, said locating means being constructed of a woven material having low thermal mass to limit conductive heat transfer between said locating means and a said sheet of heat developable material; and means for affording access to said locating means in said housing to allow insertion and removal of a sheet of heat developable material.
Claim 2
Dependent Claim
146 words
A developer for developing a sheet of heat developable material comprising: a housing having wall portions; a pair of planar heaters mounted in said housing in opposed generally parallel relationship for defining a shallow heated zone within said housing for producing essentially a uniform temperature gradient in said heated zone between said heaters; insulating material disposed between said heaters and the adjacent wall portions; planar locating means mounted generally centrally within said heated zone for positioning a said sheet of heat developable material generally parallel to said heaters within said heated zone, said locating means being constructed of a woven material having low thermal mass to limit conductive heat transfer between said locating means and a said sheet of heat developable material; and means for affording access to said locating means in said housing to allow insertion and removal of a sheet of heat developable material.
Claim 3
Dependent Claim
50 words
A developer according to claim 1 wherein said heaters have length and width dimensions which are greater than the corresponding dimensions of a said sheet to extend beyond the edges of a said sheet on the locating means by an amount at least one-half the distance between said planar heaters.
Claim 4
Dependent Claim
18 words
A developer according to claim 2 wherein said spacing between said heaters is not greater than 4 inches.
Claim 5
Dependent Claim
58 words
A developer according to claim 1 wherein said housing comprises two similar rectangular shallow boxlike members hinged along one mating edge, one of said heaters being positioned in each said boxlike member and spaced from the open side of said boxlike member, said planar locating means being positioned at the open side of one of said boxlike members.
Claim 6
Dependent Claim
29 words
A developer according to claim 1 wherein said supporting means locates a said sheet of heat developable material within the central one-fourth of said heated zone between said heaters.
Claim 7
Dependent Claim
41 words
A developer according to claim 4 comprising a timer adapted to be energized upon closure of said boxlike members to mating position and a thermostat connected to one of said heaters for regulating current flow from a source to said heaters.
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) | 1975-03-07 | 1975-09-06 | 1976-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-07 | 1979-09-06 | 1980-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-07 | 1983-09-06 | 1984-03-07 | $7700.00 | Window Closed / Lapsed |