Automatic exposure control device for copying machine
Abstract
Abstract THE EXPOSURE MECHANISM IN A COPYING MACHINE HAS ASSOCIATED THEREWITH A MEMORY ELEMENT WHICH IS DETERMINATIVE OF THE QUANTITY OF LIGHT EXPOSED TO A PHOTOSENSITIVE COPYING MEDIUM. A BRIDGE CIRCUIT CONTAINS A VARIABLE RESISTANCE ELEMENT AND A PHOTOSENSITIVE ELEMENT, THE RESISTANCE OF WHICH CHANGES WITH THE OPTICAL PROPERTIES OF AN ORIGINAL TO BE COPIED. A REVERSIBLE MOTOR OPERATES TO VARY THE VALUES OF BOTH THE MEMORY ELEMENT AND THE VARIABLE RESISTANCE ELEMENT WHEN THERE IS AN IMBALANCE IN THE BRIDGE CIRCUIT, THE DIRECTION OF WHICH VARIATIONS BEING DETERMINED BY THE POLARITY OF THE IMBALANCE. WHEN THE BRIDGE CIRCUIT IS BALANCED BY CHANGING THE RESISTANCE PRESENTED BY THE VARIABLE RESISTANCE ELEMENT, THE MOTOR CEASES TO OPERATE, THEREBY ESTABLISHING THE VALUE OF THE MEMORY ELEMENT AND THUS THE QUANTITY OF LIGHT TO BE EXPOSED TO THE PHOTOSENSITIVE COPYING MEDIUM.
Inventors
- 👤 Koji Noda
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) | 1974-06-27 | 1974-12-27 | 1975-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-27 | 1978-12-27 | 1979-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-27 | 1982-12-27 | 1983-06-28 | $7700.00 | Window Closed / Lapsed |