US3815987A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic imaging
Assignee: Bell and Howell Co
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Filing: 1972-12-27
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Granted: 1974-06-11
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Expires: 1992-12-27
Abstract
Abstract A composite recording medium comprises a photoconductive layer, a plurality of interdigitated first and second electrodes in electrical contact with the photoconductive layer, and a magnetic recording layer in heat-transfer relationship with the photoconductive layer. Methods and apparatus for magnetically recording an image with the assistance of this composite recording medium are also disclosed.
Inventors
- 👤 S Duck
- 👤 F Jeffers
- 👤 J Lemke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:25
CPC Classifications
G; G03; G03G; G03G19/00
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
113 words
Apparatus for magnetically recording an image, comprising in combination: a plurality of interdigitated first and second electrodes; a photoconductive layer in electrical contact with said interdigitated first and second electrodes; a magnetic recording layer in heat-transfer relationship With said photoconductive layer; means connected to said first and second electrodes for electrically energizing said photoconductive layer; means for exposing said electrically energized photoconductive layer to said image to provide in said recording layer a thermal pattern corresponding to said image; and means operatively associated with said magnetic recording layer for changing the state of magnetization of said recording layer in response to said thermal pattern whereby a magnetic record of said image is established.
Claim 2
Dependent Claim
113 words
Apparatus for magnetically recording an image, comprising in combination: a plurality of interdigitated first and second electrodes; a photoconductive layer in electrical contact with said interdigitated first and second electrodes; a magnetic recording layer in heat-transfer relationship With said photoconductive layer; means connected to said first and second electrodes for electrically energizing said photoconductive layer; means for exposing said electrically energized photoconductive layer to said image to provide in said recording layer a thermal pattern corresponding to said image; and means operatively associated with said magnetic recording layer for changing the state of magnetization of said recording layer in response to said thermal pattern whereby a magnetic record of said image is established.
Claim 3
Dependent Claim
54 words
Apparatus as claimed in claim 1, wherein: said photoconductive layer has a first side located at said plurality of interdigitated first and second electrodes, and has a second side opposite said first side; and said magnetic recording layer is in heat-transfer relationship with said photoconductive layer through said second side of said photoconductive layer.
Claim 4
Dependent Claim
30 words
Apparatus as claimed in claim 1, wherein: said means for changing said state of magnetization include means for premagnetizing said recording layer for subsequent image-wise demagnetization by said thermal pattern.
Claim 5
Dependent Claim
37 words
Apparatus as claimed in claim 3, wherein: said premagnetizing means include means for heating said recording layer above its Curie temperature and for subsequently magnetizing said recording layer while said recording layer cools through said Curie temperature.
Claim 6
Dependent Claim
29 words
Apparatus as claimed in claim 3, wherein: said premagnetizing means include means for magnetizing regions of said recording medium corresponding to areas between said interdigitated first and second electrodes.
Claim 7
Dependent Claim
31 words
Apparatus according to claim 1, wherein: said exposing means include means for progressively exposing said electrically energized photoconductive layer to said image in a direction in parallel to said interdigitated electrodes.
Claim 8
Dependent Claim
45 words
Apparatus according to claim 1, wherein: said exposing means include means for exposing said electrically energized photoconductive layer to said image within a band of exposure extending substantially across said interdigitated first and second electrodes and progressing in a direction parallel to said interdigitated electrodes.
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) | 1977-06-10 | 1977-12-10 | 1978-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-10 | 1981-12-10 | 1982-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-10 | 1985-12-10 | 1986-06-11 | $7700.00 | Window Closed / Lapsed |