Systems for CMOS-compatible three-dimensional image sensing using quantum efficiency modulation
US6580496B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 11, 2001 |
| Grant date | Jun 17, 2003 |
| Priority date | — |
| Expiry date | Dec 11, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S17/894
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A preferably CMOS-implementable system measures distance and/or brightness by illuminating a target with emitted optical energy having a modulated periodic waveform whose high frequency component may be idealized as S1=cos(&ohgr;·t). A fraction of the emitted optical energy is reflected by a target and detected with at least one in a plurality of semiconductor photodetectors. Photodetector quantum efficiency is modulated to process detected signals to yield data proportional to the distance z separating the target and photodetector. Detection includes measuring phase change between the emitted optical energy and the reflected fraction thereof. Quantum efficiency can be modulated with fixed or variable phase methods and may be enhanced using enhanced photocharge collection, differential modulation, and spatial and temporal multiplexing. System power requirements may be reduced with inductors that resonate with photodetector capacitance at the operating frequency. The system includes on-chip photodetectors, associated electronics, and processing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.