Light-receiving device and method for reading out signal of light-receiving device

Patent metadata

Field	Value
Publication number	US-2020177831-A1
Application number	US-201816615647-A
Country	US
Kind code	A1
Filing date	Apr 23, 2018
Priority date	May 28, 2017
Publication date	Jun 4, 2020
Grant date	—

Abstract

A light-receiving device that achieves both high saturation performance and high sensitivity performance includes a light-receiving pixel including a light-receiving element, a first capacitive element that accumulates a photoelectric charge produced by light received by the light-receiving element, a second capacitive element that accumulates a transferred portion of an amount of the photoelectric charge accumulated in the capacitive element, a switch means for turning on and off a photoelectric charge transfer operation from the capacitive element to the capacitive element, a resetting switch means for resetting the capacitive element and the capacitive element, a pixel selecting switch means, and a source follower switch means. An effective saturation capacity of the capacitive element is 10 to 5,000 times an effective saturation capacity of the capacitive element.

First claim

1 . A light-receiving device comprising:
a light-receiving pixel including a light-receiving element, a first capacitive element that accumulates a photoelectric charge produced by light received by the light-receiving element, a second capacitive element that accumulates a transferred portion of an amount of the photoelectric charge accumulated in the first capacitive element, a switch for turning on and off a photoelectric charge transfer operation from the first capacitive element to the second capacitive element, a resetting switch for resetting the first capacitive element and the second capacitive element, a pixel selecting switch means, and a source follower switch, an effective saturation capacity of the first capacitive element being 10 to 5,000 times an effective saturation capacity of the second capacitive element.

2 . A method for reading out a signal of a light-receiving device comprising:
a light-receiving pixel including a light-receiving element, a first capacitive element that accumulates a photoelectric charge produced by light received by the light-receiving element, a second capacitive element that accumulates a transferred portion of an amount of the photoelectric charge accumulated in the first capacitive element, a switch for turning on and off a photoelectric charge transfer operation from the first capacitive element to the second capacitive element, a resetting switch for resetting the first capacitive element and the second capacitive element, a pixel selecting switch, and a source follower switch, an effective saturation capacity of the first capacitive element being 10 to 5,000 times an effective saturation capacity of the second capacitive element, the method comprising: after resetting the light-receiving device as necessary, irradiating light having a light quantity capable of producing a photoelectric charge amount necessary and sufficient to fill the effective saturation capacity of the first capacitive element onto the light-receiving element to fill a capacity of the first capacitive element with a photoelectric charge produced in the light-receiving element up to the effective saturation capacity; turning on the pixel selecting switch to select the light-receiving pixel; transferring and accumulating from the first capacitive element into the second capacitive element a charge amount exceeding a potential barrier relative to the first capacitive element during transfer of a photoelectric charge from the first capacitive element to the second capacitive element by the switch; and turning on the pixel selecting switch to output from the light-receiving pixel a voltage signal corresponding to the charge amount accumulated in the second capacitive element.

Assignees

• Univ Tohoku

Inventors

• Sugawa Shigetoshi
• Kuroda Rihito

Classifications

• G01J1/46 Primary

  using a capacitor · CPC title

• H04N5/378 Primary

  Electricity · mapped topic

• H04N5/372

  Electricity · mapped topic

• H04N25/71

  Charge-coupled device [CCD] sensors; Charge-transfer registers specially adapted for CCD sensors · CPC title

• H04N25/59

  by controlling the amount of charge storable in the pixel, e.g. modification of the charge conversion ratio of the floating node capacitance · CPC title