Pixel circuit with capacitor discharge indicative of number of events
US9313434B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 2013 |
| Grant date | Apr 12, 2016 |
| Priority date | — |
| Expiry date | Jun 2, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S17/894
- 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 circuit is operable to discharge a known portion of the charge on the capacitance upon each detection of a SPAD event within a time period, such that the charge remaining on the capacitance at the end of the time period corresponds to the number of SPAD events detected within the time period. A time resolved imaging apparatus includes an array of such pixel circuits. A method of counting photon detection includes sensing photons with a SPAD device and discharging a known portion of the charge on a capacitance upon each detection of a SPAD event within a time period.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.