PIXEL-LEVEL OVERSAMPLING FOR A TIME OF FLIGHT 3D IMAGE SENSOR WITH DUAL RANGE MEASUREMENTS

摘要

A time of flight pixel cell includes a photosensor to sense photons reflected from an object. Pixel support circuitry including charging control logic is coupled to the photosensor to detect when the photosensor senses the photons reflected from the object, and coupled to receive timing signals representative of when light pulses are emitted from a light source. A controllable current source is coupled to receive a time of flight signal form the charging control logic to provide a charge current when a light pulse emitted from the light source until the photosensor senses a respective one of the photons reflected from the object. A capacitor is coupled to receive the charge current, and a voltage on the capacitor is representative of a round trip distance to the object. A reset circuit is coupled to reset the voltage on the capacitor after being charged a plurality number of times.

主权项

1. A time of flight pixel cell, comprising:
a photosensor to sense photons reflected from an object; and pixel support circuitry including:
charging control logic coupled to the photosensor to detect when the photosensor senses the photons reflected from the object, wherein the charging control logic is further coupled to receive timing signals representative of when light pulses are emitted from a light source to the object;a controllable current source coupled to provide a charge current in response to a time of flight signal coupled to be received from the charging control logic, wherein the time of flight signal is representative of a time of flight of each one of the light pulses emitted from the light source until the photosensor senses a respective one of the photons reflected from the object;a capacitor coupled to receive the charge current from the controllable current source in response to the time of flight signal, wherein a voltage on the capacitor is representative of a round trip distance to the object; anda reset circuit coupled to reset the voltage on the capacitor after being charged a plurality number of times by the controllable current source in response to the time of flight signal.