US 12,276,761 B2
Phase anti-aliasing using spread-spectrum techniques in an optical distance measurement system
Subhash Chandra Venkata Sadhu, Bengaluru (IN); Bharath Patil, Bengaluru (IN); and Jaiganesh Balakrishnan, Bengaluru (IN)
Assigned to Texas Instruments Incorporated, Dallas, TX (US)
Filed by TEXAS INSTRUMENTS INCORPORATED, Dallas, TX (US)
Filed on Oct. 22, 2020, as Appl. No. 17/077,315.
Application 17/077,315 is a continuation of application No. 15/834,178, filed on Dec. 7, 2017, granted, now 10,852,402.
Prior Publication US 2021/0041541 A1, Feb. 11, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. G01S 7/48 (2006.01); G01S 7/484 (2006.01); G01S 7/486 (2020.01); G01S 7/4865 (2020.01); G01S 7/4911 (2020.01); G01S 17/10 (2020.01); G01S 17/34 (2020.01); G01S 17/89 (2020.01); G01S 17/894 (2020.01)
CPC G01S 7/4911 (2013.01) [G01S 7/484 (2013.01); G01S 7/4865 (2013.01); G01S 7/4868 (2013.01); G01S 17/10 (2013.01); G01S 17/34 (2020.01); G01S 17/89 (2013.01); G01S 17/894 (2020.01)] 21 Claims
OG exemplary drawing
 
1. A three dimensional (3D) time of flight (TOF) system, comprising:
a transmitter configured to:
generate an electrical transmit signal at a plurality of frequencies over an integration time period; and
generate a transmit optical waveform corresponding with the electrical transmit signal; and
a receiver configured to:
receive a reflected optical waveform that is the transmit optical waveform reflected off of a target object;
integrate the reflected optical waveform over the integration time period, the integration time period including a plurality of exposure time periods, wherein each exposure time period in the plurality of exposure time periods is different from the other exposure time periods; and
determine a distance to the target object based on a TOF of the transmit optical waveform from the transmitter to the target object and back to the receiver as the reflected optical waveform, the TOF determined based on a correlation of the electrical transmit signal and the reflected optical waveform utilizing a correlation function with respect to the integration time period.