公开(公告)号：US12270952B2

公开(公告)日：2025-04-08

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 ,  G01S17/89 ,  G01S17/894

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：US11543504B2

公开(公告)日：2023-01-03

申请号：US16855287

申请日：2020-04-22

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： Bharath Patil ,  Anjana Sharma ,  Subhash Chandra Venkata Sadhu ,  Ravishankar Ayyagari

IPC: G01S7/497 ,  G01S17/36 ,  G01S17/894

Abstract: Systems and methods are provided for imaging a surface via time of flight measurement. An illumination system includes an illumination driver and an illumination source and is configured to project modulated electromagnetic radiation to a point on a surface of interest. A sensor system includes a sensor driver and is configured to receive and demodulate electromagnetic radiation reflected from the surface of interest. A temperature sensor is configured to provide a measured temperature representing a temperature at one of the illumination driver and the sensor driver and located at a position remote from the one of the illumination driver and the sensor driver. A compensation component is configured to calculate a phase offset between the illumination system and the sensor system from at least the measured temperature and a model representing transient heat flow within the system.

公开(公告)号：US20150308949A1

公开(公告)日：2015-10-29

申请号：US14698978

申请日：2015-04-29

Applicant: Texas Instruments Incorporated

Inventor： Subhash Chandra Venkata Sadhu ,  Bharath Patil

IPC: G01N21/55 ,  H05B37/02 ,  G01J1/46

CPC classification number: G01J1/46 ,  G01N2223/506 ,  G01S7/484 ,  H05B33/0815 ,  H05B37/0272 ,  Y02B20/346

Abstract: The disclosure provides a circuit to mitigate ripple. The circuit includes a controller that generates a PWM (pulse width modulated) clock signal. A DC/DC converter receives the PWM clock signal, and generates an output signal. A light source is coupled to the DC/DC converter, and receives the output signal. The light source transmits light pulses during an integration time. A time integral of the output signal during the integration time is constant during a plurality of quad time periods.

Abstract translation: 本公开提供了一种减轻纹波的电路。 该电路包括产生PWM（脉宽调制）时钟信号的控制器。 DC / DC转换器接收PWM时钟信号，并产生输出信号。 光源耦合到DC / DC转换器，并接收输出信号。 光源在积分时间内传输光脉冲。 积分时间期间的输出信号的时间积分在多个四倍时间段期间是恒定的。

公开(公告)号：US10663566B2

公开(公告)日：2020-05-26

申请号：US15729060

申请日：2017-10-10

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： Bharath Patil ,  Anjana Sharma ,  Subhash Chandra Venkata Sadhu ,  Ravishankar Ayyagari

IPC: G01S7/497 ,  G01S17/89 ,  G01S17/36

Abstract: Systems and methods are provided for imaging a surface via time of flight measurement. An illumination system includes an illumination driver and an illumination source and is configured to project modulated electromagnetic radiation to a point on a surface of interest. A sensor system includes a sensor driver and is configured to receive and demodulate electromagnetic radiation reflected from the surface of interest. A temperature sensor is configured to provide a measured temperature representing a temperature at one of the illumination driver and the sensor driver and located at a position remote from the one of the illumination driver and the sensor driver. A compensation component is configured to calculate a phase offset between the illumination system and the sensor system from at least the measured temperature and a model representing transient heat flow within the system.

公开(公告)号：US20180031682A1

公开(公告)日：2018-02-01

申请号：US15729060

申请日：2017-10-10

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： Bharath Patil ,  Anjana Sharma ,  Subhash Chandra Venkata Sadhu ,  Ravishankar Ayyagari

IPC: G01S7/497 ,  G01S17/89 ,  G01S17/36

Abstract: Systems and methods are provided for imaging a surface via time of flight measurement. An illumination system includes an illumination driver and an illumination source and is configured to project modulated electromagnetic radiation to a point on a surface of interest. A sensor system includes a sensor driver and is configured to receive and demodulate electromagnetic radiation reflected from the surface of interest. A temperature sensor is configured to provide a measured temperature representing a temperature at one of the illumination driver and the sensor driver and located at a position remote from the one of the illumination driver and the sensor driver. A compensation component is configured to calculate a phase offset between the illumination system and the sensor system from at least the measured temperature and a model representing transient heat flow within the system.

公开(公告)号：US20150078001A1

公开(公告)日：2015-03-19

申请号：US14486057

申请日：2014-09-15

Applicant: Texas Instruments Incorporated

Inventor： Bharath Patil ,  Karthik Rajagopal ,  Subhash Chandra Venkata Sadhu

IPC: G02B27/48

CPC classification number: G02B27/48

Abstract: Laser speckle reduction using a passive diffuser. A diffuser for reducing laser speckle is disclosed comprising a diffuser having a colloid configured for placement in a light path of a coherent light source. The colloid exhibits Brownian motion. The diffuser can be formed of transparent plates containing the colloid. In a system for illumination, a coherent source of light outputting a light beam along a light path is provided; and a diffuser for reducing laser speckle effects is placed in the light path, the diffuser comprising a colloid disposed in a container that is transparent to the light beam output by the coherent source. A method includes illuminating a photosensitive sensor, comprising transmitting a coherent light from a light source through a diffuser comprising a colloid and directing the light from the diffuser onto the photosensitive sensor. Additional embodiments are disclosed.

Abstract translation: 使用无源漫射器进行激光散斑减光。 公开了一种用于减少激光散斑的漫射器，其包括具有配置用于放置在相干光源的光路中的胶体的扩散器。 胶体呈现布朗运动。 扩散器可以由含有胶体的透明板形成。 在照明系统中，提供沿光路输出光束的相干光源; 并且用于减少激光散斑效应的扩散器被放置在光路中，扩散器包括设置在由相干光源输出的光束透明的容器中的胶体。 一种方法包括照射光敏传感器，包括从光源通过包括胶体的扩散器传输相干光并将来自扩散器的光引导到感光传感器上。 公开了另外的实施例。

公开(公告)号：US11880001B2

公开(公告)日：2024-01-23

申请号：US16834385

申请日：2020-03-30

Applicant: Texas Instruments Incorporated

Inventor： Subhash Chandra Venkata Sadhu

IPC: G01S7/48 ,  G01S7/484 ,  G01S7/4865 ,  G01S17/10 ,  G01S17/894 ,  G01S17/931

CPC classification number: G01S7/484 ,  G01S7/4865 ,  G01S17/10 ,  G01S17/894 ,  G01S17/931

Abstract: An optical transmitting system for distance measuring includes a modulation signal generator, a light source, and an illumination driver coupled to the modulation signal generator and the light source. The modulation signal generator is configured to generate a modulation signal. The light source is configured to generate an optical waveform with amplitude modulation corresponding with the modulation signal. The illumination driver is configured to drive the light source. The illumination driver includes a switch and a switch driver. The switch is configured to switch between an on state and an off state to drive the light source. The switch driver is configured to drive the switch between the on and off states. The switch driver includes a first inductor and a capacitor in series with the first inductor and the switch.

公开(公告)号：US10852402B2

公开(公告)日：2020-12-01

申请号：US15834178

申请日：2017-12-07

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： Subhash Chandra Venkata Sadhu ,  Bharath Patil ,  Jaiganesh Balakrishnan

IPC: G01S7/4865 ,  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：US09323071B2

公开(公告)日：2016-04-26

申请号：US14486057

申请日：2014-09-15

Applicant: Texas Instruments Incorporated

Inventor： Bharath Patil ,  Karthik Rajagopal ,  Subhash Chandra Venkata Sadhu

IPC: F21V11/00 ,  G02B27/20 ,  G02B27/48

CPC classification number: G02B27/48

Abstract: Laser speckle reduction using a passive diffuser. A diffuser for reducing laser speckle is disclosed comprising a diffuser having a colloid configured for placement in a light path of a coherent light source. The colloid exhibits Brownian motion. The diffuser can be formed of transparent plates containing the colloid. In a system for illumination, a coherent source of light outputting a light beam along a light path is provided; and a diffuser for reducing laser speckle effects is placed in the light path, the diffuser comprising a colloid disposed in a container that is transparent to the light beam output by the coherent source. A method includes illuminating a photosensitive sensor, comprising transmitting a coherent light from a light source through a diffuser comprising a colloid and directing the light from the diffuser onto the photosensitive sensor. Additional embodiments are disclosed.

Abstract translation: 使用无源漫射器进行激光散斑减光。 公开了一种用于减少激光散斑的漫射器，其包括具有配置用于放置在相干光源的光路中的胶体的扩散器。 胶体呈现布朗运动。 扩散器可以由含有胶体的透明板形成。 在照明系统中，提供沿光路输出光束的相干光源; 并且用于减少激光散斑效应的扩散器被放置在光路中，扩散器包括设置在由相干光源输出的光束透明的容器中的胶体。 一种方法包括照射光敏传感器，包括从光源通过包括胶体的扩散器传输相干光并将来自扩散器的光引导到感光传感器上。 公开了另外的实施例。

公开(公告)号：US12276761B2

公开(公告)日：2025-04-15

申请号：US17077315

申请日：2020-10-22

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： Subhash Chandra Venkata Sadhu ,  Bharath Patil ,  Jaiganesh Balakrishnan

IPC: G01S7/48 ,  G01S7/484 ,  G01S7/486 ,  G01S7/4865 ,  G01S7/4911 ,  G01S17/10 ,  G01S17/34 ,  G01S17/89 ,  G01S17/894

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.