发明名称 |
Pixel circuit with capacitor discharge indicative of number of events |
摘要 |
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. |
申请公布号 |
US9313434(B2) |
申请公布日期 |
2016.04.12 |
申请号 |
US201314066853 |
申请日期 |
2013.10.30 |
申请人 |
STMicroelectronics (Research & Development) Limited |
发明人 |
Dutton Neale;Henderson Robert Kerr |
分类号 |
H01L31/107;H04N5/3745;G01S17/89;G01S7/486 |
主分类号 |
H01L31/107 |
代理机构 |
Gardere Wynne Sewell LLP |
代理人 |
Gardere Wynne Sewell LLP |
主权项 |
1. A pixel circuit, comprising:
a single photon avalanche diode (SPAD) configured to detect SPAD events; a measurement circuit comprising a capacitance, wherein said measurement circuit is operable to discharge a portion of the charge on said capacitance upon each SPAD event detection within a time period, such that the charge remaining on said capacitance at the end of the time period corresponds to the number of SPAD events detected within the time period; and a time gating stage operable to begin sensing operation on reception of an enable signal and comprising:
a switch operable to selectively connect the SPAD output to the measurement circuit on reception of said enable signal; andtwo further switches operable to disable the pixel circuit on reception of a disable signal. |
地址 |
Marlow GB |