Motor controlling circuit of reproducing apparatus and method of controlling
US4481615A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 26, 1982 |
| Grant date | Nov 6, 1984 |
| Priority date | — |
| Expiry date | Jan 26, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B19/28
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A reproducing apparatus comprises a motor (9) for driving a digital audio disk (1), in which digital data and a synchronizing signal are recorded. The digital data is modulated in accordance with a predetermined digital modulating system such as an EFM modulating system, and is then recorded, while the synchronizing signal is recorded which includes the repetition number of the signals of the maximum period included in the digital data which repetition number is larger than that in the digital data. A signal is reproduced from the disk and the reproduced signal is subjected to FM demodulation and then a control signal is generated based on the FM demodulated signal. The generated control signal as well as a reference signal is applied to a phase comparator (7) constituting a phase locked loop (10), whereby the phase locked loop controls the rotational speed of the motor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.