US3717460A
Expired / Lapsed
US
⏱️ 0.0 years remaining
A method of imaging 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 a magnetic recording layer in heat-transfer relationship 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
- 👤 S Duck
- 👤 F Jeffers
- 👤 J Lemke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:57
CPC Classifications
G; G03; G03G; G03G19/00
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
149 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 in electrical contact with and contiguous to said interdigitated first and second electrodes; providing in heat-transfer relationship with and contiguous to said photoconductive layer a magnetic image recording layer susceptible to an image-wise change of magnetization in response to a thermal image pattern; 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 and exposing said photoconductive layer to said image to produce 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 recording layer in response to said thermal pattern.
Claim 2
Independent Claim
149 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 in electrical contact with and contiguous to said interdigitated first and second electrodes; providing in heat-transfer relationship with and contiguous to said photoconductive layer a magnetic image recording layer susceptible to an image-wise change of magnetization in response to a thermal image pattern; 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 and exposing said photoconductive layer to said image to produce 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 recording layer in response to said thermal pattern.
Claim 3
Dependent Claim
58 words
A method as claimed in claim 1, wherein: said photoconductive layer is provided with a first side located at said plurality of interdigitated first and second electrodes, and with a second side opposite said first side; and said magnetic recording layer is provided in heat-transfer relationship with said photoconductive layer through said second side of said photoconductive layer.
Claim 4
Dependent Claim
49 words
A method as claimed in claim 1, wherein: the state of magnetization of said recording layer is changed by premagnetizing said recording layer and heating with said thermal pattern portions of said premagnetized recording layer corresponding to said pattern so as to demagnetize said portions of said recording layer.
Claim 5
Dependent Claim
29 words
A method as claimed in claim 3, wherein: said recording layer is premagnetized by cooling said recording layer through its Curie temperature in the presence of a magnetic field.
Claim 6
Dependent Claim
62 words
A method as claimed in claim 3, wherein: said recording layer is premagnetized by thermoremanent magnetization including a heating of said recording layer with the assistance of an electrical energization and a progressive exposure of said photoconductive layer in a direction progressing in parallel to said electrodes, and a subsequent cooling of said recording layer in the presence of a magnetic field.
Claim 7
Dependent Claim
27 words
A method as claimed in claim 1, wherein: said photoconductive layer is progressively exposed to said image in a direction progressing in parallel to said interdigitated electrodes.
Claim 8
Dependent Claim
40 words
A method as claimed in claim 1, wherein: said photoconductive layer is exposed 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.
Claim 9
Independent Claim
162 words
A method of magnetically recording an image on a composite recording medium, which medium includes a photoconductive layer, a plurality of interdigitated first and second electrodes in electrical contact with and contiguous to said photoconductive layer, and, in heat-transfer relationship with and contiguous to said photoconductive layer, a magnetic image recording layer susceptible to an image-wise change of magnetization in response to a thermal Image pattern, comprising in combination the steps of: 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 and progressively exposing said photoconductive layer to said image in a direction progressing parallel to said interdigitated electrodes to produce 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 recording layer in response to said thermal pattern.
Claim 10
Independent Claim
162 words
A method of magnetically recording an image on a composite recording medium, which medium includes a photoconductive layer, a plurality of interdigitated first and second electrodes in electrical contact with and contiguous to said photoconductive layer, and, in heat-transfer relationship with and contiguous to said photoconductive layer, a magnetic image recording layer susceptible to an image-wise change of magnetization in response to a thermal Image pattern, comprising in combination the steps of: 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 and progressively exposing said photoconductive layer to said image in a direction progressing parallel to said interdigitated electrodes to produce 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 recording layer in response to said thermal pattern.
Claim 11
Dependent Claim
40 words
A method as claimed in claim 8, wherein: said photoconductive layer is exposed 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.
Claim 12
Dependent Claim
49 words
A method as claimed in claim 8, wherein: the state of magnetization of said recording layer is changed by premagnetizing said recording layer and heating with said thermal pattern portions of said premagnetized recording layer corresponding to said pattern so as to demagnetize said portions of said recording layer.
Claim 13
Dependent Claim
29 words
A method as claimed in claim 10, wherein: said recording layer is premagnetized by cooling said recording layer through its Curie temperature in the presence of a magnetic field.
Claim 14
Dependent Claim
62 words
A method as claimed in claim 10, wherein: said recording layer is premagnetized by thermoremanent magnetization including a heating of said recording layer with the assistance of an electrical energization and a progressive exposure of said photoconductive layer in a direction progressing in parallel to said electrodes, and a subsequent cooling of said recording layer in the presence of a magnetic field.
Claim 15
Dependent Claim
72 words
A composite photoelectric 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 in electrical contact with and contiguous to said interdigitated first and second electrodes; and a thermally responsive magnetic image recording layer contiguous to said photoconductive layer.
Claim 16
Dependent Claim
72 words
A composite photoelectric 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 in electrical contact with and contiguous to said interdigitated first and second electrodes; and a thermally responsive magnetic image recording layer contiguous to said photoconductive layer.
Claim 17
Dependent Claim
24 words
A composite recording medium as claimed in claim 13, including: a transparent substrate carrying said interdigitated first and second electrodes and said photoconductive layer.
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 |