A signal extraction circuit, a signal extraction method, and a ranging method and device

Abstract

Embodiments of the present invention provide a signal extraction circuit, a signal extraction method, and a ranging method and apparatus. The method for signal extraction and the distance measurement method includes: using a circuit in the sensor to perform multiple signal extraction to obtain multiple extraction results; and determining the distance to the object to be measured according to the multiple extraction results. By inventing a new signal extraction circuit, the method of the present invention reduces the capacitance by half compared with the pixel circuit in the prior art, thereby significantly increasing the effective area in the pixel and reducing the calculation error caused by the capacitance difference between different capacitors , and completes some calculations in the process of signal extraction, which reduces the pressure of post-stage data processing, especially in the process of ranging, which greatly improves the accuracy and speed of ranging.

Description

technical field [0001] The present invention relates to the technical field of microelectronics, and in particular, to a signal extraction circuit, a signal extraction method, and a ranging method and device. Background technique [0002] This section is intended to provide a background or context for the embodiments of the invention that are recited in the claims. The descriptions herein are not admitted to be prior art by inclusion in this section. [0003] During the imaging process of the image sensor, the signals received by the pixels of the image sensor inevitably contain the background light signal. In the actual imaging process, the effective signal and the background light need to be separated to obtain the required image or detection information. Especially in the field of TOF (Time of Flight, time of flight) ranging, the so-called TOF ranging is to continuously send light pulses to the target, and then use the sensor to receive the light returned from the object...

AI Technical Summary

Problems solved by technology

Especially in the field of TOF (Time of Flight, time of flight) ranging, the so-called TOF ranging is to continuously send light pulses to the target, and then use the sensor to receive the light returned from the object after being reflected by the object. The returned light includes The echo signal of the light pulse and the background light signal of other ambient light directly incident or reflected by the object are detected, and the distance to the object to be measured is obtained by detecting the flight (round-trip) time of the echo signal of the light pulse , in TOF ranging, the working conditions of large background light bring challenges to the demand for high-precision ranging

In order to eliminate the interference of background light, it is necessary to receive the corresponding charge amount converted from the signal including the echo signal and background light through multiple capacitors, and receive the corresponding charge amount converted from the signal including only the background light, and then calculate the corresponding echo When the signal is extracted, multiple capacitors lead to a waste of pixel area on the one hand, and on the other hand, calculation errors are caused by the capacitance difference between different capacitors, which in turn leads to ranging errors

Moreover, the required data cannot be directly measured, and the demand for a large amount of fast data processing in the entire array puts a lot of pressure on the post-processing unit

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