Patent US3868681A successfully refreshed from Google Patents.
US3868681A
Expired / Lapsed
US
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Character input equipment
Assignee: NEC Corp
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Filing: 1972-09-21
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Granted: 1975-02-25
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Expires: 1992-09-21
Abstract
Abstract Electronic hardware especially adapted for use in converting each one of a group of characters into binary digital information comprising a character matrix for visually identifying each selectable character. An electronic matrix positioned beneath the character matrix and comprised of perpendicularly aligned drive and sense line sets is pulsed in a predetermined sequential fashion to create current pulses in each of the current drive lines. A bar which is selectively positionable adjacent any one of the characters creates an inductive path between the drive and sense lines which intersect at the location of the desired character causing a detection circuit to indicate this condition and terminate the sequential stepping. The sense lines are provided with activating circuits for selectively coupling each of the sense lines to the detection means which halts the operations of the drive and sense line control circuits when the desired character has been detected. The outputs of the drive and sense line control circuits may then be converted into binary digital information representing any one of the selectable characters.
Inventors
- 👤 Chishio Ohyama
- 👤 Makoto Tachibana
- 👤 Takeshi Takada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 20:26
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/01; G06F3/03; G06F3/041; G06F3/046
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
345 words
A character input equipment comprising: a character plate having a plurality of characters arranged in rows and columns in a matrix form; a plurality of pairs of spaced parallel current drive lines disposed corresponding to each row direction beneath said character plate; a drive means having a plurality of current drive circuits for sequentially supplying a drive current pulse to said pairs of current drive lines one pair at a time; a plurality of pairs of spaced parallel sense lines disposed corresponding to each column under the plate and perpendicularly intersecting the plurality of current drive lines whereby the four intersections formed by each pair of drive and sense lines underlies one of said characters; a sense signal detection circuit; sense means coupled to said drive means and having sense line selection circuits for sequentially coupling one of said sense line pairs to said detection circuit said sense means being advanced after all of said drive lines have received a drive current pulse; a single indication bar adapted to be positioned in close proximity to the character plate and at any location along the surface thereof for selecting a desired character on the plate and for electromagnetically coupling a pair of current drive lines with a pair of sense lines corresponding to the character associated therewith; said sense signal detection circuit having means for detecting current changes in the sense line pair connected thereto and caused by bringing the bar close to a desired character on said plate when one Of the drive line pairs is pulsed, said current being supplied to the current drive line corresponding to the desired character in the row position on the character plate; means coupled to said detection circuit for halting the stepping of said drive line circuits when said detection means is activated; and means coupled to said drive circuits and said sense line circuits for transferring the binary outputs thereof and relating to the selected character to utilization means whereby the binary signals correspond to the character on the character plate upon which said bar is positioned.
Claim 2
Dependent Claim
345 words
A character input equipment comprising: a character plate having a plurality of characters arranged in rows and columns in a matrix form; a plurality of pairs of spaced parallel current drive lines disposed corresponding to each row direction beneath said character plate; a drive means having a plurality of current drive circuits for sequentially supplying a drive current pulse to said pairs of current drive lines one pair at a time; a plurality of pairs of spaced parallel sense lines disposed corresponding to each column under the plate and perpendicularly intersecting the plurality of current drive lines whereby the four intersections formed by each pair of drive and sense lines underlies one of said characters; a sense signal detection circuit; sense means coupled to said drive means and having sense line selection circuits for sequentially coupling one of said sense line pairs to said detection circuit said sense means being advanced after all of said drive lines have received a drive current pulse; a single indication bar adapted to be positioned in close proximity to the character plate and at any location along the surface thereof for selecting a desired character on the plate and for electromagnetically coupling a pair of current drive lines with a pair of sense lines corresponding to the character associated therewith; said sense signal detection circuit having means for detecting current changes in the sense line pair connected thereto and caused by bringing the bar close to a desired character on said plate when one Of the drive line pairs is pulsed, said current being supplied to the current drive line corresponding to the desired character in the row position on the character plate; means coupled to said detection circuit for halting the stepping of said drive line circuits when said detection means is activated; and means coupled to said drive circuits and said sense line circuits for transferring the binary outputs thereof and relating to the selected character to utilization means whereby the binary signals correspond to the character on the character plate upon which said bar is positioned.
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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) | 1978-02-24 | 1978-08-26 | 1979-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-24 | 1982-08-26 | 1983-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-24 | 1986-08-26 | 1987-02-25 | $7700.00 | Window Closed / Lapsed |