US 12,248,071 B2
3D time-of-flight camera and method of detecting three-dimensional image data
Matthias Heinz, Waldkirch (DE); Thorsten Pfister, Waldkirch (DE); and Josef Baak, Waldkirch (DE)
Assigned to SICK AG, Waldkirch (DE)
Filed by SICK AG, Waldkirch (DE)
Filed on Nov. 25, 2020, as Appl. No. 17/104,443.
Claims priority of application No. 10 2019 131 988.9 (DE), filed on Nov. 26, 2019.
Prior Publication US 2021/0157007 A1, May 27, 2021
Int. Cl. G01S 17/894 (2020.01); G01S 7/4915 (2020.01); G01S 17/931 (2020.01)
CPC G01S 17/894 (2020.01) [G01S 7/4915 (2013.01); G01S 17/931 (2020.01)] 16 Claims
OG exemplary drawing
 
1. A method of detecting three-dimensional image data from a detection zone, comprising:
transmitting transmission light that is modulated with a first modulation frequency;
receiving reception light from the detection zone and generating a plurality of reception signals therefrom with spatial resolution;
demodulating the reception signals with the first modulation frequency;
making amplitude measurements of the demodulated reception signals in order to obtain sampled values corresponding to the amplitude measurements;
making a number of subsequent amplitude measurements to obtain a plurality of subsequent sampled values, wherein each of the subsequent measurements is performed on subsequent reception signals demodulated with the first modulation frequency and at a known phase shift from the first modulation frequency of the transmission light, wherein the known phase shift of each of the subsequent measurements has a unique value;
determining a respective distance value from the sampled values and the subsequent sampled values, wherein the number of subsequent amplitude measurements is selectively adjustable; and
performing calibration, wherein the calibration is performed with a stored calibration data set selected from a plurality of stored calibration data sets, the selected one of the stored calibration data sets having a number associated therewith matching the number of the subsequent amplitude measurements.