Encoded data card system
Abstract
Abstract THIS INVENTION RELATES TO A HIGH BIT DENSITY ENCODED DATA CARD AND CODE DETECTOR WHEREIN THE DATA IS CONCEALED FROM THE OBSERVER THEREOF. THE CARD COMPRISES A THIN METALLIC PLATE OF A NON-FERROUS OR FERROUS MATERIAL IN WHICH A PLURALITY OF HOLES ARE SELECTIVELY PLACED. THE CODE DETECTOR COMPRISES A PLURALITY OF CONDUCTIVE SQUARES OR CIRCULES UPON AN INSULATED BOARD, THE HOLES OF THE CARD BEING SELECTIVELY PLACED TO CORRESPOND SPACIALLY WITH THE CONDUCTORS OF THE BOARD. WHEN AN AUDIO FREQUENCY VOLTAGE IS APPLIED IN PROXIMITY TO THE CARD BY MEANS OF A CONDUCTIVE PLATE PLACED THEREON BUT INSULATED THEREFROM, VOLTAGE WILL BE CAPACITIVELY COUPLED ONLY TO THOSE CONDUCTORS OF THE BOARD WHICH ARE OPPOSITE THE HOLES OF THE CARD. D R A W I N G
Inventors
- 👤 D Cohen
Bibliographic Details
Claims Analysis
Total Claims: 0References Cited (Backward Citations)
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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) | 1976-02-13 | 1976-08-14 | 1977-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-13 | 1980-08-14 | 1981-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-13 | 1984-08-14 | 1985-02-13 | $7700.00 | Window Closed / Lapsed |