Patents by Inventor Subhash Chandra Venkata Sadhu
Subhash Chandra Venkata Sadhu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
-
Patent number: 11880001Abstract: 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.Type: GrantFiled: March 30, 2020Date of Patent: January 23, 2024Assignee: TEXAS INSTRUMENTS INCORPORATEDInventor: Subhash Chandra Venkata Sadhu
-
Patent number: 11543504Abstract: 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.Type: GrantFiled: April 22, 2020Date of Patent: January 3, 2023Assignee: TEXAS INSTRUMENTS INCORPORATEDInventors: Bharath Patil, Anjana Sharma, Subhash Chandra Venkata Sadhu, Ravishankar Ayyagari
-
Patent number: 11143552Abstract: 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.Type: GrantFiled: April 29, 2015Date of Patent: October 12, 2021Assignee: TEXAS INSTRUMENTS INCORPORATEDInventors: Subhash Chandra Venkata Sadhu, Bharath Patil
-
Publication number: 20210181323Abstract: 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.Type: ApplicationFiled: February 1, 2021Publication date: June 17, 2021Inventors: Subhash Chandra Venkata SADHU, Bharath PATIL
-
Patent number: 10935641Abstract: 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.Type: GrantFiled: October 30, 2017Date of Patent: March 2, 2021Assignee: TEXAS INSTRUMENTS INCORPORATEDInventors: Subhash Chandra Venkata Sadhu, Bharath Patil
-
Publication number: 20210041541Abstract: 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.Type: ApplicationFiled: October 22, 2020Publication date: February 11, 2021Inventors: Subhash Chandra Venkata SADHU, Bharath PATIL, Jaiganesh BALAKRISHNAN
-
Patent number: 10852402Abstract: 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.Type: GrantFiled: December 7, 2017Date of Patent: December 1, 2020Assignee: TEXAS INSTRUMENTS INCORPORATEDInventors: Subhash Chandra Venkata Sadhu, Bharath Patil, Jaiganesh Balakrishnan
-
Publication number: 20200249331Abstract: 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.Type: ApplicationFiled: April 22, 2020Publication date: August 6, 2020Inventors: Bharath Patil, Anjana Sharma, Subhash Chandra Venkata Sadhu, Ravishankar Ayyagari
-
Publication number: 20200225323Abstract: 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.Type: ApplicationFiled: March 30, 2020Publication date: July 16, 2020Inventor: Subhash Chandra Venkata Sadhu
-
Patent number: 10663566Abstract: 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.Type: GrantFiled: October 10, 2017Date of Patent: May 26, 2020Assignee: TEXAS INSTRUMENTS INCORPORATEDInventors: Bharath Patil, Anjana Sharma, Subhash Chandra Venkata Sadhu, Ravishankar Ayyagari
-
Patent number: 10641869Abstract: 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.Type: GrantFiled: July 28, 2017Date of Patent: May 5, 2020Assignee: TEXAS INSTRUMENTS INCORPORATEDInventor: Subhash Chandra Venkata Sadhu
-
Publication number: 20190178993Abstract: 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.Type: ApplicationFiled: December 7, 2017Publication date: June 13, 2019Inventors: Subhash Chandra Venkata SADHU, Bharath PATIL, Jaiganesh BALAKRISHNAN
-
Publication number: 20190129017Abstract: 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.Type: ApplicationFiled: October 30, 2017Publication date: May 2, 2019Inventors: Subhash Chandra Venkata SADHU, Bharath PATIL
-
Publication number: 20180031682Abstract: 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.Type: ApplicationFiled: October 10, 2017Publication date: February 1, 2018Inventors: Bharath Patil, Anjana Sharma, Subhash Chandra Venkata Sadhu, Ravishankar Ayyagari
-
Publication number: 20180031676Abstract: 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.Type: ApplicationFiled: July 28, 2017Publication date: February 1, 2018Inventor: Subhash Chandra Venkata SADHU
-
Patent number: 9323071Abstract: 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.Type: GrantFiled: September 15, 2014Date of Patent: April 26, 2016Assignee: TEXAS INSTRUMENTS INCORPORATEDInventors: Bharath Patil, Karthik Rajagopal, Subhash Chandra Venkata Sadhu
-
Publication number: 20150308949Abstract: 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.Type: ApplicationFiled: April 29, 2015Publication date: October 29, 2015Inventors: Subhash Chandra Venkata Sadhu, Bharath Patil
-
Publication number: 20150253417Abstract: 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.Type: ApplicationFiled: March 9, 2015Publication date: September 10, 2015Inventors: BHARATH PATIL, ANJANA SHARMA, SUBHASH CHANDRA VENKATA SADHU, RAVISHANKAR AYYAGARI
-
Publication number: 20150078001Abstract: 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.Type: ApplicationFiled: September 15, 2014Publication date: March 19, 2015Inventors: Bharath Patil, Karthik Rajagopal, Subhash Chandra Venkata Sadhu