US3717459A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of imaging involving pre-heating using interdigitated electrodes, a photoconductive layer and a magnetic imaging layer
Assignee: Bell and Howell Co
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Filing: 1970-04-17
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Granted: 1973-02-20
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Expires: 1990-04-17
Abstract
Abstract A composite recording medium comprises a photoconductive layer, a plurality of interdigitated first and second electrodes in electrical contact with and contiguous to the photoconductive layer, and an electrically conductive magnetic recording layer in electrical contact with and contiguous to 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
2026-10-25 11:24
CPC Classifications
G; G03; G03G; G03G5/00; G03G5/16; G03G19/00
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
219 words
A method of magnetically recording an image, comprising in combination the steps of: providing a plurality of interdigitated first and second electrodes; providing a photoconductive layer electrically connected and contiguous to said interdigitated first and second electrodes; providing an electrically conductive magnetic image recording layer susceptible to an image-wise change of magnetization in response to a thermal image pattern and electrically connected to said interdigitated first and second electrodes and contiguous to said photoconductive layer; connecting said interdigitated first and second electrodes to opposite terminals, respectively, of a source of electric energy; applying electrical energy from said source to said interdigitated first and second electrodes by way of said opposite terminals to provide electrical currents through said electrically conductive magnetic recording layer so as to pre-heat said magnetic recording layer to a temperature below the temperature at which said image-wise change of magnetization occurs; exposing said photoconductive layer to said image and continuing to apply electrical energy from said source to said interdigitated electrodes by way of said opposite terminals so as to produce with the aid of electrical energy from said source a thermal pattern corresponding to said image and constituting said thermal image pattern; and magnetically recording said image by changing the state of magnetization of said heated recording layer with the aid of said thermal pattern.
Claim 2
Independent Claim
219 words
A method of magnetically recording an image, comprising in combination the steps of: providing a plurality of interdigitated first and second electrodes; providing a photoconductive layer electrically connected and contiguous to said interdigitated first and second electrodes; providing an electrically conductive magnetic image recording layer susceptible to an image-wise change of magnetization in response to a thermal image pattern and electrically connected to said interdigitated first and second electrodes and contiguous to said photoconductive layer; connecting said interdigitated first and second electrodes to opposite terminals, respectively, of a source of electric energy; applying electrical energy from said source to said interdigitated first and second electrodes by way of said opposite terminals to provide electrical currents through said electrically conductive magnetic recording layer so as to pre-heat said magnetic recording layer to a temperature below the temperature at which said image-wise change of magnetization occurs; exposing said photoconductive layer to said image and continuing to apply electrical energy from said source to said interdigitated electrodes by way of said opposite terminals so as to produce with the aid of electrical energy from said source a thermal pattern corresponding to said image and constituting said thermal image pattern; and magnetically recording said image by changing the state of magnetization of said heated recording layer with the aid of said thermal pattern.
Claim 3
Dependent Claim
30 words
A method 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 4
Dependent Claim
66 words
A method as claimed in claim 1, wherein: said interdigitated first and second electrodes are located on a 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 so as to be electrically connected to said first and second interdigitated electrodes through portions of said photoconductive layer.
Claim 5
Dependent Claim
26 words
A method as claimed in claim 1, wherein: said photoconductive layer is progressively exposed to said image in a direction progressing parallel to said interdigitated electrodes.
Claim 6
Dependent Claim
27 words
A method as claimed in claim 1, wherein: said interdigitated electrodes are made to protrude into said photoconductive layer in a direction toward said magnetic recording layer.
Claim 7
Dependent Claim
31 words
A method 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 8
Dependent Claim
56 words
A method as claimed in claim 1, wherein: said electrically conductive magnetic recording layer is provided by a process including the steps of providing acicular magnetic recording medium particles having long axes and short axes, and orienting said recording particles so that said long axes substantially extend in geometrical planes intersecting said first and second electrodes.
Claim 9
Dependent Claim
32 words
A method as claimed in claim 7, wherein: said acicular particles are so oriented that said long axes substantially extend in geometrical planes intersecting said first and second electrodes at right angles.
Claim 10
Dependent Claim
112 words
A photoelectric composite recording medium operable with a source of electric energy having opposite terminals, comprising in combination: a plurality of interdigitated first and second electrodes; said interdigitated first and second electrodes connected to opposite terminals, respectively, of said source of electric energy; a photoconductive layer electrically connected and contiguous to said interdigitated first and second electrodes; and a thermally responsive electrically conductive magnetic image recording layer electrically connected to said interdigitated first and second electrodes and contiguous to said photoconductive layer, 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 11
Dependent Claim
112 words
A photoelectric composite recording medium operable with a source of electric energy having opposite terminals, comprising in combination: a plurality of interdigitated first and second electrodes; said interdigitated first and second electrodes connected to opposite terminals, respectively, of said source of electric energy; a photoconductive layer electrically connected and contiguous to said interdigitated first and second electrodes; and a thermally responsive electrically conductive magnetic image recording layer electrically connected to said interdigitated first and second electrodes and contiguous to said photoconductive layer, 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 12
Dependent Claim
30 words
A composite recording medium as claimed in claim 9, 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) | 1976-02-20 | 1976-08-21 | 1977-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-20 | 1980-08-21 | 1981-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-20 | 1984-08-21 | 1985-02-20 | $7700.00 | Window Closed / Lapsed |