US3778145A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic imaging
Assignee: Bell and Howell Co
•
Filing: 1972-12-27
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Granted: 1973-12-11
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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 an electrically conductive magnetic recording layer in electrical contact with the photoconductive layer. Methods and apparatus for magnetically recording an image with the assistance of this composite recording medium are also disclosed.
Inventors
- 👤 R Mcclure
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:34
CPC Classifications
G; G03; G03G; G03G5/00; G03G5/16; G03G19/00
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
29 words
Apparatus as claimed in claim 1, wherein: said electrically conductive magnetic recording layer is electrically connected to said interdigitated first and second electrodes through portions of said photoconductive layer.
Claim 2
Dependent Claim
30 words
Apparatus as claimed in claim 1, wherein: said exposing means include means for progressively exposing said photoconductive layer to said image in a direction progressing parallel to said interdigitated electrodes.
Claim 3
Dependent Claim
51 words
Apparatus as claimed in claim 1, wherein: said apparatus includes a substrate; said interdigitated first and second electrodes are located on said substrate; said photoconductive layer is located on said substrate and said interdigitated first and second electrodes; and said electrically conductive magnetic recording layer is located on said photoconductive layer.
Claim 4
Dependent Claim
23 words
Apparatus as claimed in claim 1, wherein: said interdigitated electrodes protrude into said photoconductive layer in a direction toward said magnetic recording layer.
Claim 5
Dependent Claim
30 words
Apparatus as claimed in claim 1, wherein: each of said interdigitated first and second electrodes is spaced more from each of the adjacent electrodes than from said magnetic recording layer.
Claim 6
Dependent Claim
37 words
Apparatus as claimed in claim 1, wherein: said electrically conductive magnetic recording layer comprises acicular magnetic recording medium particles having short axes, and having long axes extending substantially in geometrical planes intersecting said first and second electrodes.
Claim 7
Dependent Claim
27 words
Apparatus as claimed in claim 7, wherein: said long axes of said particles extend substantially in geometrical planes intersecting said first and second electrodes at right angles.
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) | 1976-12-10 | 1977-06-11 | 1977-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-10 | 1981-06-11 | 1981-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-10 | 1985-06-11 | 1985-12-11 | $7700.00 | Window Closed / Lapsed |