US3689934A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for magnetic recording of electronic signals
Assignee: EIDP Inc
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Filing: 1970-10-08
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Granted: 1972-09-05
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Expires: 1990-10-08
Abstract
Abstract A cathode ray tube having a faceplate composed of a thin nonmagnetic gas-impermeable plate having a pattern of indentations on the innerface, the indentations being at least partially filled with a finely particulate hard magnetic material, preferably having a Curie temperature below 500* C. is described. Images in the form of a pattern of magnetization are formed on the faceplate thermomagnetically by the heating effect of the electron beam. The image on the faceplate can then be transferred to a magnetic recording member external to the cathode ray tube by thermoremanent transfer.
Inventors
- 👤 George Raymond Nacci
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:26
CPC Classifications
G; G03; G03G; G03G19/00; H; H01; H01J; H01J29/00; H01J29/02; H01J29/10; H01J31/00; H01J31/08
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
43 words
Apparatus of claim 1 in which said indentations are spaced at a distance less than the resolution distance of the information to be recorded and said indentations extending to a point less than the resolution distance from the exterior of said evacuated envelope.
Claim 2
Dependent Claim
15 words
Apparatus of claim 2 in which said finely particulate hard magnetic material is chromium dioxide.
Claim 3
Dependent Claim
186 words
Apparatus of claim 1 additionally comprising: means to modulate the intensity and direction of said beam in accordance with information supplied as electronic signals, whereby a sequence of lines of information are recorded thermomagnetically on said faceplate; means to apply a magnetic field to said faceplate in timed relationship with said lines, electronic information to return said recording members to its original state after each line and to provide magnetic conditions for thermomagnetic recording; a magnetic recording member having a coating of a finely particulate hard magnetic material with a Curie temperature less than 500* C.; means to move successive portions of said magnetic recording member into the field of magnetic signals of said faceplate whereby a different portion of said magnetic recording member is present as each line is recorded on said faceplate; and heating means adapted and arranged to transiently heat the magnetic material of said recording member to a temperature of about the Curie temperature at the end of each line but before the faceplate is restored to its initial condition whereby signals on said faceplate are transferred thermoremanently to said recording member.
Claim 4
Dependent Claim
32 words
Apparatus of claim 4 is which the coercivity of the finely particulate magnetic material of the magnetic recording member is greater than the coercivity of finely particulate magnetic material of the faceplate.
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) | 1975-09-05 | 1976-03-06 | 1976-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-05 | 1980-03-06 | 1980-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-05 | 1984-03-06 | 1984-09-05 | $7700.00 | Window Closed / Lapsed |