Absolute encoding apparatus
US4183014A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 21, 1977 |
| Grant date | Jan 8, 1980 |
| Priority date | — |
| Expiry date | Jan 21, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/30
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
First and second similar rotary encoders are interconnected such that the first encoder actuates the second encoder to advance one position for each half revolution of the first encoder. The first encoder is coupled to monitor the position of a rotary component. If the encoders are shifted or off-set by up to 90.degree. to either side of precise zero crossover alignment, a logic comparator modifies the reading of the second encoder to create a true read-out. During each half revolution of the first encoder, the second encoder should read even or odd if a proper phasing exists. If the second encoder produces an opposite reading, a phase shift is indicated. A logic circuit, preferably a microprocessor is provided for combining and modifying the readout in accordance with the logic. A microprocessor includes a program to continuously sample the position of the successive encoders with an internal table applied to the position readouts to provide a correct and true value of the rotary component position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.