公开(公告)号：US09989657B2

公开(公告)日：2018-06-05

申请号：US15335588

申请日：2016-10-27

Applicant: HAMAMATSU PHOTONICS K.K.

Inventor： Shigeyuki Nakamura ,  Tsuyoshi Ohta ,  Michito Hirayanagi ,  Hiroki Suzuki ,  Shunsuke Adachi

IPC: G01T1/24 ,  G01T1/18 ,  H01L31/02

CPC classification number: G01T1/247 ,  G01T1/18 ,  H01L31/02027

Abstract: A readout circuit for reading out an output current from a photoelectric conversion element which collectively outputs currents generated in a plurality of pixels, each of which includes an avalanche photodiode, includes a current mirror circuit configured to receive the output current and output first and second currents having magnitudes in proportion to the output current, a photon counting circuit configured to count the number of photons incident on the photoelectric conversion element on the basis of the first current, an integral circuit configured to integrate the second current to generate a voltage signal, and a signal processing unit configured to determine a magnitude of light incident on the photoelectric conversion element on the basis of a counting result output from the photon counting circuit and a magnitude of the voltage signal output from the integral circuit.