Capstan servo system in a recording and/or reproducing apparatus
US4249220A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 7, 1978 |
| Grant date | Feb 3, 1981 |
| Priority date | — |
| Expiry date | Nov 7, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B15/46
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A capstan servo system is used in a recording and/or reproducing apparatus which is capable of recording/reproducing either video signals of the NTSC system having a frame frequency of 30 Hz or video signals of the CCIR system having a frame frequency of 25 Hz. The capstan servo system detects the rotation of a capstan for driving a tape and produces an output frequency which is divided. A reference signal has a frequency corresponding to the frame frequency of the system of the video signal to be recorded on and/or reproduced from the tape. There is a phase comparison between the frequency divided signal and the reference signal. The frequency of the output signal of the detector is added to an error signal output of the phase comparison circuit. The resulting sum signal is used to control the rotation of the motor for driving the capstan. The detection circuit produces an output signal having a frequency of 150.multidot.M Hz (where M is a positive integer). The frequency division is capable of dividing the frequency of the output signal of the detection circuit with a selected frequency division ratio of 1/5M or 1/6M.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.