Envelope detection circuit for detection of opening angle of a movable MEMS mirror
US11226480B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 10, 2020 |
| Grant date | Jan 18, 2022 |
| Priority date | — |
| Expiry date | Jul 24, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P25/032
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An electronic device includes an analog to digital converter receiving an analog mirror sense signal from an oscillating mirror and generating a digital mirror sense signal therefrom, and a digital signal processing block. The digital signal processing block cooperates with the analog to digital converter to take a first sample of the digital mirror sense signal at a first time where a derivative of capacitance of the digital mirror sense signal crosses zero, take a second sample of the digital mirror sense signal at a second time between a peak of the digital mirror sense signal and the first time, and take a third sample of the digital mirror sense signal at a third time after the digital mirror sense signal has reached a minimum. Control circuitry determines an opening angle of the oscillating mirror as a function of the first, second, and third samples.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.