Detecting device of an encoder
US6252584A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 20, 1998 |
| Grant date | Jun 26, 2001 |
| Priority date | — |
| Expiry date | Nov 20, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/03543
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A detecting device of an encoder is disclosed. The detecting device comprises a photodetector and a detection circuit. The photodetector has three active areas, and the detection circuit compares each two of the electric signals outputted from the three active areas for deriving a digital waveform with a desired phase and duty cycle. Thus, the digital signal may be correctly decoded into a vector data by a digital circuit in the next stage. The shift of signal level induced from the decay of LED may be avoided. The defect of a prior art optomechanical encoder is also avoided. In the prior art encoder, a fixed voltage is used as a comparing voltage and thus the encoded signal could be too strong or too weak due to the variation of the sensitivities of different photodetectors and the difference in the light intensities of the LEDs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.