公开(公告)号：US20210041541A1

公开(公告)日：2021-02-11

申请号：US17077315

申请日：2020-10-22

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： Subhash Chandra Venkata SADHU ,  Bharath PATIL ,  Jaiganesh BALAKRISHNAN

IPC: G01S7/4865 ,  G01S17/89 ,  G01S7/484 ,  G01S7/486 ,  G01S17/10 ,  G01S7/4911 ,  G01S17/34

Abstract: A three dimensional time of flight (TOF) camera includes a transmitter and a receiver. The transmitter is 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. The receiver is configured to receive a reflected optical waveform that is the transmit optical waveform reflected off of an object, integrate the reflected optical waveform over the integration time period, and determine a distance to the target object based on a TOF of the optical waveform. The integration time period includes exposure time periods. A length of each of the exposure time periods corresponds to one of the frequencies. The TOF is determined based on a correlation of the electrical transmit signal and the return optical waveform utilizing a correlation function with respect to the integration time period.

公开(公告)号：US20190129017A1

公开(公告)日：2019-05-02

申请号：US15796930

申请日：2017-10-30

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： Subhash Chandra Venkata SADHU ,  Bharath PATIL

IPC: G01S7/491 ,  G01S17/36

Abstract: A distance measurement system includes a light transmitter to generate a modulated light signal, a light sensor to generate measurement signals from reflected light among four quad phase angles with respect to a phase of the generated light signal, and a controller. The controller selects a first set of quad phase angles, and generates first measurement signals at the quad phase angles of the first set. Based on the first measurement signals, the controller computes a first phase angle between the generated light signal and the reflected light signal, generates a second set of quad phase angles based on the first phase angle, and generates second measurement signals at the quad phase angles of the second set. Further, based on the second measurement signals, the controller computes a second phase angle between the generated light signal and the reflected light signal and calculates a distance using the second phase angle.

公开(公告)号：US20210181323A1

公开(公告)日：2021-06-17

申请号：US17163601

申请日：2021-02-01

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： Subhash Chandra Venkata SADHU ,  Bharath PATIL

IPC: G01S7/4915 ,  G01S17/36 ,  G01S17/894 ,  G01S17/89

Abstract: A distance measurement system includes a light transmitter to generate a modulated light signal, a light sensor to generate measurement signals from reflected light among four quad phase angles with respect to a phase of the generated light signal, and a controller. The controller selects a first set of quad phase angles, and generates first measurement signals at the quad phase angles of the first set. Based on the first measurement signals, the controller computes a first phase angle between the generated light signal and the reflected light signal, generates a second set of quad phase angles based on the first phase angle, and generates second measurement signals at the quad phase angles of the second set. Further, based on the second measurement signals, the controller computes a second phase angle between the generated light signal and the reflected light signal and calculates a distance using the second phase angle.

公开(公告)号：US20200209392A1

公开(公告)日：2020-07-02

申请号：US16235667

申请日：2018-12-28

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： Venkata Subhash Chandra SADHU ,  Bharath PATIL ,  Nithin JOSE ,  Shubham AGRAWAL

IPC: G01S17/10 ,  G01S17/89 ,  G06T7/521

Abstract: A time of flight (ToF) system includes a light source, a photosensor, a signal generator and a processor. The signal generator outputs a reference signal corresponding to a modulation function for modulated light and a modified transmitted light signal corresponding to a phase shift of the reference signal. The light source outputs the modified transmitted light signal and pixels in the photosensor receives its reflections off the scene. The reference signal is applied to the pixels and the processor determines a depth map for the scene based on values recorded by the pixels. In some examples, the phase shift is implemented using a phase locked loop controller. One or more component phases of the phase shift and an exposure time for each component phase are determined and output by the phase locked loop controller.

公开(公告)号：US20190178993A1

公开(公告)日：2019-06-13

申请号：US15834178

申请日：2017-12-07

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： Subhash Chandra Venkata SADHU ,  Bharath PATIL ,  Jaiganesh BALAKRISHNAN

IPC: G01S7/486 ,  G01S17/89 ,  G01S17/10 ,  G01S7/484

Abstract: A three dimensional time of flight (TOF) camera includes a transmitter and a receiver. The transmitter is 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. The receiver is configured to receive a reflected optical waveform that is the transmit optical waveform reflected off of an object, integrate the reflected optical waveform over the integration time period, and determine a distance to the target object based on a TOF of the optical waveform. The integration time period includes exposure time periods. A length of each of the exposure time periods corresponds to one of the frequencies. The TOF is determined based on a correlation of the electrical transmit signal and the return optical waveform utilizing a correlation function with respect to the integration time period.