Digital servo system using microcomputer for controlling phase and speed of rotary body
US4885793A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 8, 1988 |
| Grant date | Dec 5, 1989 |
| Priority date | — |
| Expiry date | Feb 8, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S388/912
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A microcomputer (20) servo controls the rotational speed and the rotational phase of a cylinder motor (37) of a VTR in a digital manner. The microcomputer (20) generates a 10-bit digital phase error signal D.sub.PH having sufficiently low conversion gain and a 10-bit digital speed error signal D.sub.SP having sufficiently low conversion gain in response to an FG signal generated with rotation of a cylinder motor. The digital phase error signal D.sub.PH and the digital speed error signal D.sub.SP are added to each other in a digital manner in the addition ratio 1:8. In addition, the result of this addition is amplified four times in a digital manner by extracting eight lower order bits thereof and then converted into an analogue signal and supplied to the cylinder motor as a servo control signal. Thus, since the error signals are added to each other in a digital manner and then, the added signal is amplified as required, a digital servo having a large capture range can be achieved as whole.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.