Light source driving circuit, light source driving method and flight time distance measuring sensor

Abstract

The invention relates to a light source driving circuit, a light source driving method and a flight time distance measuring sensor. The light source driving circuit comprises a light source, a first switching circuit, a second switching circuit and a constant current control circuit, a positive electrode of the light source is connected to a power end, a positive electrode of the first switching circuit is connected to a negative electrode of the light source, a negative electrode of the first switching circuit is connected with a low-potential point and used for controlling the on-off state of the negative electrode of the light source and the low-potential point, one end of the second switching circuit is connected to the positive electrode of the light source, the other end of the second switching circuit is connected to the negative electrode of the first switching circuit and used for controlling the on-off state of the power end and the low-potential point, one end of the constant current control circuit is connected to the negative electrode of the light source, and the other end of the constant current control circuit is connected to the low-potential point. When the constant current control circuit is on, constant current passes the light source and is lower than luminous threshold current of the light source. The light source driving circuit can reduce the influence of circuit parasitic inductance.

Description

technical field [0001] The invention relates to the field of electronic technology, in particular to a light source driving circuit, a light source driving method and a time-of-flight ranging sensor. Background technique [0002] The Time Of Flight (TOF) method realizes the measurement of the three-dimensional structure or three-dimensional profile of the measured object by measuring the time interval from the emission to the reception of the pulse signal sent by the measuring instrument or the phase generated by the laser going back and forth to the measured object once. TOF measuring instruments can obtain grayscale images and distance images at the same time, and are widely used in many fields such as somatosensory control, behavior analysis, monitoring, automatic driving, artificial intelligence, machine vision, and automatic 3D modeling. [0003] Time-of-flight ranging (TOF) sensors generally include: a light source module and a photosensitive module; Received: the pho...

AI Technical Summary

Problems solved by technology

[0005] However, in the prior art, due to various parasitic parameters in the circuit, especially the parasitic inductance, there is an inductive reactance effect on the current change, so that the rise or fall of the pulse edge of the light source will cause a delay, or even a non-ideal process. Shock, affecting the sensing performance of the sensor

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