Pixel circuit with controlled capacitor discharge time of flight measurement
US9171985B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 2013 |
| Grant date | Oct 27, 2015 |
| Priority date | — |
| Expiry date | Jul 19, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/771
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A pixel circuit includes a single photon avalanche diode (SPAD) and a measurement circuit including a capacitance. The SPAD detects an incident photon and the measurement circuit discharges the capacitance at a known rate during a discharge time period. The length of the discharge time period is determined by the time of detection of the photon, such that the final amount of charge on the capacitance corresponds to the time of flight of the photon. The pixel circuit may be included in a time resolved imaging apparatus. A method of measuring the time of flight of a photon includes responding to an incident photon detection by discharging a capacitance at a known rate and correlating final capacitance charge to time of flight.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.