Patent US4442441A successfully refreshed from Google Patents.
US4442441A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording device
Assignee: Fujifilm Business Innovation Corp
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Filing: 1981-02-19
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Granted: 1984-04-10
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Expires: 2001-02-19
Abstract
Abstract A device for recording predetermined magnetization patterns on a magnetic recording medium such as for use in a copying machine. The magnetic medium is first magnetized with a uniform magnetization pattern then passed to a thermal printing head upon which a number of heat generating elements are arranged one-dimensionally on a supporting substrate. The heat generating elements are selectively activated to heat the recording magnetic medium to a temperature greater than the Curie temperature thereof so as to change the direction of the magnetization of the magnetic medium in cooperation with a biasing magnetic field.
Inventors
- 👤 Yoshiki Kikuchi
- 👤 Takashi Omori
- 👤 Haruhiko Moriguchi
- 👤 Fujio Moriguchi
- 👤 Tomio Murayama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:43
CPC Classifications
G; G01; G01D; G01D15/00; G01D15/12
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
148 words
A magnetic recording device comprising: a magnetic medium having an initial uniform magnetization pattern in which desired portions are selectively magnetized in a latent image pattern; a thermal printing head having a supporting substrate and a plurality of heat generating elements arranged on said supporting substrate, said magnetic medium moving relative to said thermal printing head; means for supplying heating current selectively to said heat generating elements according to data to be recorded so that said magnetic medium is locally heated by selected ones of said heat generating elements to a temperature greater than the Curie temperature of said magnetic medium as it moves relative to said thermal printing head; a confronting roll disposed confronting said thermal printing head through said magnetic medium; and a biasing magnet provided inside said confronting roll for applying a biasing magnetic field to predetermined portions of said magnetic medium which are heated.
Claim 2
Dependent Claim
148 words
A magnetic recording device comprising: a magnetic medium having an initial uniform magnetization pattern in which desired portions are selectively magnetized in a latent image pattern; a thermal printing head having a supporting substrate and a plurality of heat generating elements arranged on said supporting substrate, said magnetic medium moving relative to said thermal printing head; means for supplying heating current selectively to said heat generating elements according to data to be recorded so that said magnetic medium is locally heated by selected ones of said heat generating elements to a temperature greater than the Curie temperature of said magnetic medium as it moves relative to said thermal printing head; a confronting roll disposed confronting said thermal printing head through said magnetic medium; and a biasing magnet provided inside said confronting roll for applying a biasing magnetic field to predetermined portions of said magnetic medium which are heated.
Claim 3
Dependent Claim
28 words
The magnetic recording device as claimed in claim 1 which further comprises: means for preheating said magnetic medium to a predetermined temperature lower than the Curie temperature thereof.
Claim 4
Dependent Claim
21 words
The magnetic recording device as claimed in claim 1 wherein said heat generating elements are arranged one-dimensionally on said supporting substrate.
Claim 5
Dependent Claim
16 words
The magnetic recording device as claimed in claim 1 wherein said biasing magnet is rotatably mounted.
Claim 6
Dependent Claim
151 words
A magnetic recording device comprising: a magnetic medium having an initial uniform magnetization pattern in which desired portions are selectively magnetized in a latent image pattern; a thermal printing head having a supporting substrate and a plurality of heat generating elements arranged on said supporting substrate, said magnetic medium moving relative to said thermal printing head; means for supplying heating current selectively to said heat generating elements according to data to be recorded so that said magnetic medium is locally heated by selected ones of said heat generating elements to a temperature greater than the Curie temperature of said magnetic medium as it moves relative to said thermal printing head; a confronting roll disposed confronting said thermal printing head through said magnetic medium; and a biasing magnet provided below said thermal printing head for applying a biasing magnetic field to predetermined portions of said magnetic medium through said thermal printing head.
Claim 7
Dependent Claim
151 words
A magnetic recording device comprising: a magnetic medium having an initial uniform magnetization pattern in which desired portions are selectively magnetized in a latent image pattern; a thermal printing head having a supporting substrate and a plurality of heat generating elements arranged on said supporting substrate, said magnetic medium moving relative to said thermal printing head; means for supplying heating current selectively to said heat generating elements according to data to be recorded so that said magnetic medium is locally heated by selected ones of said heat generating elements to a temperature greater than the Curie temperature of said magnetic medium as it moves relative to said thermal printing head; a confronting roll disposed confronting said thermal printing head through said magnetic medium; and a biasing magnet provided below said thermal printing head for applying a biasing magnetic field to predetermined portions of said magnetic medium through said thermal printing head.
Claim 8
Dependent Claim
17 words
The magnetic recording device as claimed in claim 5 wherein said biasing magnet comprises a bar magnet.
Claim 9
Dependent Claim
16 words
The magnetic recording device as claimed in claim 6 wherein said biasing magnet is rotatably mounted.
Claim 10
Dependent Claim
38 words
The magnetic recording device as claimed in claim 5 wherein said confronting roll has a hollow inner portion and further comprising a yoke member disposed within said hollow portion confronting said thermal printing head through said magnetic medium.
Claim 11
Dependent Claim
17 words
The magnetic recording device as claimed in claim 5 wherein said biasing magnet comprises a horseshoe-shaped magnet.
Claim 12
Dependent Claim
40 words
The magnetic recording device as claimed in any of claims 1 or 3-9 wherein said magnetic medium comprises a material selected from the group consisting of copper zinc ferrite, manganese zinc ferrite, nickel zinc ferrite, chromium oxide and Gd-Co alloy.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-04-10 | 1987-10-10 | 1988-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-04-10 | 1991-10-10 | 1992-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-04-10 | 1995-10-10 | 1996-04-10 | $7700.00 | Window Closed / Lapsed |