US3663764A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic tracking circuit for transverse scan magnetic tape transport
Assignee: Ampex Corp
•
Filing: 1970-04-06
•
Granted: 1972-05-16
•
Expires: 1990-04-06
Abstract
Abstract In order to provide automatic tracking during playback operation of a transverse scan tape transport, a low amplitude and low frequency signal is applied to the capstan drive in addition to the nominal playback drive signal such that the prerecorded transverse information tracks vacillate about an on-center tracking phase relationship with the rotary record/reproduce head wheel. The high frequency playback information signal from the rotary head wheel is thereby amplitude modulated in accordance with the varying tracking registration between the head wheel and transverse tracks. The amplitude modulation of the playback information signal is thereupon detected, and the frequency, phase and amplitude relationships between this detected signal and the signal employed for exciting the capstan drive are compared to provide a control signal for advancing or retarding the longitudinal tape movement until the transverse tracks and rotary head wheel are in optimum tracking phase relationship.
Inventors
- 👤 Allen J Trost
- 👤 Reginald W Oldershaw
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:25
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/60; G11B15/602
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
256 words
An automatic tracking control circuit for a transverse scan tape transport which includes a capstan drive for longitudinal translation of magnetic tape and a rotary magnetic head assembly rotating in a path transverse to said tape for reproducing transverse tracks of prerecorded information, wherein said circuit comprises: an electrical source issuing a sinusoidally varying electrical signal, said source being connected to the capstan drive for sinusoidally varying the translation speed of the tape; amplitude detector means coupled to the magnetic head assembly for detecting amplitude variations in the reproduced transverse track signal information, said detector having a frequency sensitivity below a predetermined frequency range of said prerecorded information; filter means passing signal frequencies at the frequency of said source signal, said filter being connected to the output of said detector means; a comparator having electrical storage means, an output means connected to said storage means and input switching means connected between said filter means and said storage means, said switching means being connected and responsive to said source for sampling and passing the instantaneous magnitude of the signal issued by said filter means to said storage means in response to each cycle of said sinusoidal source signal; and feedback circuit means connected between said comparator output means and the capstan drive and being responsive to frequency and phase correspondence of signals from said source and said comparator means to issue a control signal to said capstan drive for adjusting the translation of said tape to maintain optimum registration between said head assembly and said transverse tracks.
Claim 2
Dependent Claim
256 words
An automatic tracking control circuit for a transverse scan tape transport which includes a capstan drive for longitudinal translation of magnetic tape and a rotary magnetic head assembly rotating in a path transverse to said tape for reproducing transverse tracks of prerecorded information, wherein said circuit comprises: an electrical source issuing a sinusoidally varying electrical signal, said source being connected to the capstan drive for sinusoidally varying the translation speed of the tape; amplitude detector means coupled to the magnetic head assembly for detecting amplitude variations in the reproduced transverse track signal information, said detector having a frequency sensitivity below a predetermined frequency range of said prerecorded information; filter means passing signal frequencies at the frequency of said source signal, said filter being connected to the output of said detector means; a comparator having electrical storage means, an output means connected to said storage means and input switching means connected between said filter means and said storage means, said switching means being connected and responsive to said source for sampling and passing the instantaneous magnitude of the signal issued by said filter means to said storage means in response to each cycle of said sinusoidal source signal; and feedback circuit means connected between said comparator output means and the capstan drive and being responsive to frequency and phase correspondence of signals from said source and said comparator means to issue a control signal to said capstan drive for adjusting the translation of said tape to maintain optimum registration between said head assembly and said transverse tracks.
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) | 1975-05-16 | 1975-11-15 | 1976-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-16 | 1979-11-15 | 1980-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-16 | 1983-11-15 | 1984-05-16 | $7700.00 | Window Closed / Lapsed |