US3182135A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for checking imperfections in a recording medium
Assignee: US Philips Corp
•
Filing: 1962-04-02
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Granted: 1965-05-04
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Expires: 1982-04-02
Abstract
No abstract record available.
Inventors
- 👤 Siezen Gerrit Jan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:54
CPC Classifications
G; G11; G11B; G11B3/00; G11B23/00; G11B23/30
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
98 words
APPARATUS FOR DETECTING IMPERFORATIONS IN A RECORDING MEDIUM, COMPRISING: MEANS FOR RECORDING ON SAID MEDIUM A SIGNAL HAVING A RELATIVELY WIDE FREQUENCY RANGE FROM WHICH A RELATIVELY NARROW FREQUENCY BAND IS SUBSTANTIALLY SUPPRESSED, THE EXTENT OF SAID NARROW BAND BEING SUCH THAT ITS ABSENCE IS SUBSTANTIALLY INAUDIBLE WHEN REPRODUCED, REPRODUCING MEANS FOR REPRODUCING SAID SIGNAL, THE REPRODUCED SIGNAL BEING APPLIED TO A BAND-PASS FILTER TUNED TO SAID NARROW FREQUENCY BAND, THE OUTPUT OF SAID BAND-PASS FILTER BEING APPLIED TO AS CONTROL AMPLIFIER, MEANS COUPLED TO SAID CONTROL AMPLIFIER FOR VARYING THE AMPLIFICATION FACTOR OF SAID CONTROL AMPLIFIER RESPONSIVE
References Cited (Backward Citations)
US1989965A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-05-03 | 1968-11-02 | 1969-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-05-03 | 1972-11-02 | 1973-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-05-03 | 1976-11-02 | 1977-05-04 | $7700.00 | Window Closed / Lapsed |