Patent US3911481A successfully refreshed from Google Patents.
US3911481A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Visual and magnetic recording systems
Assignee: Individual
•
Filing: 1973-12-28
•
Granted: 1975-10-07
•
Expires: 1993-12-28
Abstract
Abstract Disclosed is a system for visually and magnetically recording data indicative of characters on opposite sides of a paper sheet having a magnetizable backing. The data are recorded with a typewriter which includes a head for recording coded magnetic bits indicative of each character visually printed on the sheet. The head is coreless and is comprised of a plurality of windings, only certain of the windings write or record bipolarity magnetic bits onto the backing, the remaining windings serve as both spacer and erase windings. Recording is accomplished by feeding large amplitude, short duration current pulses to the recording windings. The magnetic bits for each magnetically recorded character are selectively erased by applying bipolarity, low duty-cycle pulses of successively lower amplitudes to the backing by way of the windings and different modes of erasing various areas on the recording medium are disclosed. Also disclosed is a system for decoding the magnetic bits stored on the backing, wherein a head sequentially scans a rotating line of magnetic bits and sequentially reads out each character of the line. The entire document is read by stepping the head from line to line.
Inventors
- 👤 Joseph R Andreaggi
- 👤 Robert J Graf
- 👤 Matthew J Relis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:06
CPC Classifications
B; B41; B41J; B41J3/00; B41J3/44; B41J3/50
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
227 words
The combination of a typewriter apparatus having a plurality of typewriter keys and a magnetic recording system for recording magnetic bits on a magnetizable medium mounted on the typewriter platen, the recording system comprising a plurality of stages for producing high-ampereage currents, the flow directions of certain currents being different and coded to represent different ones of the typewriter keys, each of said stages including a first and a second control device having at least one control electrode, an output electrode and a third electrode, first and second capacitors under the control of said devices, the first capacitor coupling the output electrode of said second device to the third electrode of said first device and the second capacitor coupling the output electrode of said first device to the third electrode of said second device, means for charging said capacitors prior to actuation of a typewriter key, means coupled to the control electrodes of said devices and responsive to actuation of a typewriter key for activating one said devices, whereby one of said capacitors discharges current through the output electrode of the one device, and a conductor associated with each of said stages mounted adjacent said platen and said medium and connected to the one output electrode for inducing a magnetic flux in said magnetic medium of polarity determined by the direction of current flow in said conductor.
Claim 2
Dependent Claim
227 words
The combination of a typewriter apparatus having a plurality of typewriter keys and a magnetic recording system for recording magnetic bits on a magnetizable medium mounted on the typewriter platen, the recording system comprising a plurality of stages for producing high-ampereage currents, the flow directions of certain currents being different and coded to represent different ones of the typewriter keys, each of said stages including a first and a second control device having at least one control electrode, an output electrode and a third electrode, first and second capacitors under the control of said devices, the first capacitor coupling the output electrode of said second device to the third electrode of said first device and the second capacitor coupling the output electrode of said first device to the third electrode of said second device, means for charging said capacitors prior to actuation of a typewriter key, means coupled to the control electrodes of said devices and responsive to actuation of a typewriter key for activating one said devices, whereby one of said capacitors discharges current through the output electrode of the one device, and a conductor associated with each of said stages mounted adjacent said platen and said medium and connected to the one output electrode for inducing a magnetic flux in said magnetic medium of polarity determined by the direction of current flow in said conductor.
Claim 3
Dependent Claim
35 words
The combination as claimed in claim 1 which additionally comprises, means for selectively deactivating said control devices of all said stages to prevent magnetization of said medium upon activation of certain of the typewriter keys.
Claim 4
Dependent Claim
38 words
The combination as claimed by claim 2 which additionally comprises, means activated by a shift key on the typewriter for generating a predetermined current flow in one of said conductors of a change from lower to upper case.
Claim 5
Dependent Claim
131 words
The combination of a typewriter apparatus having a plurality of keys and a system for recording an erasing discrete magnetized areas on a magnetizable medium mounted in the typewriter apparatus comprising, a recording head having a plurality of parallel juxtaposed conductors facing said medium in adjacency therewith, first means for generating current flows to certain ones of said conductors upon actuation of a selected key in directions which represent such key whereby a first discrete area of the medium is magnetized by induction from the currents, and second means responsive to actuation of said selected key for generating current flows in other ones of said conductors to magnetically erase a second discrete area of the medium contiguous to the first area and in the direction of medium movement in the typewriter.
Claim 6
Dependent Claim
131 words
The combination of a typewriter apparatus having a plurality of keys and a system for recording an erasing discrete magnetized areas on a magnetizable medium mounted in the typewriter apparatus comprising, a recording head having a plurality of parallel juxtaposed conductors facing said medium in adjacency therewith, first means for generating current flows to certain ones of said conductors upon actuation of a selected key in directions which represent such key whereby a first discrete area of the medium is magnetized by induction from the currents, and second means responsive to actuation of said selected key for generating current flows in other ones of said conductors to magnetically erase a second discrete area of the medium contiguous to the first area and in the direction of medium movement in the typewriter.
Claim 7
Dependent Claim
46 words
The combination as claimed in claim 4 wherein said other ones of saiD conductors are interleaved with said certain ones of said conductors and wherein said selected key is a back space key, whereby activation of said backspace key erases and area prior to recording thereon.
Claim 8
Dependent Claim
52 words
The combination as claimed in claim 4 wherein the other ones of said conductors are positioned on each side of said certain ones of said conductors to effect erasure of areas fringing said first discrete area, and means coupling the second generating means to all of said other ones of said conductors.
Claim 9
Dependent Claim
25 words
The combination as claimed in claim 4 which further comprises means for selectively applying the second generating means to said certain ones of said conductors.
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) | 1978-10-06 | 1979-04-07 | 1979-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-06 | 1983-04-07 | 1983-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-06 | 1987-04-07 | 1987-10-07 | $7700.00 | Window Closed / Lapsed |