Patents by Inventor Xinqiao Liu

Xinqiao Liu 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: 10679366
    Abstract: A depth measurement assembly (DMA) includes a structured light emitter, an augmented camera, and a controller. The structured light emitter projects structured light into a local area under instructions from the controller. The augmented camera generates image data of an object illuminated with the structured light pattern projected by the structured light emitter in accordance with camera instructions generated by the controller. The augmented camera includes a high speed computation tracking sensor that comprises a plurality of augmented photodetectors. Each augmented photodetector converts light to data and stores the data in its own memory unit. The controller receives the image data and determines depth information of the object in the local area based in part on the image data. The depth measurement unit can be incorporated into a head-mounted display (HMD).
    Type: Grant
    Filed: December 27, 2017
    Date of Patent: June 9, 2020
    Assignee: Facebook Technologies, LLC
    Inventors: Xinqiao Liu, Richard Andrew Newcombe, Steven John Lovegrove, Renzo De Nardi
  • Publication number: 20200162722
    Abstract: A depth camera assembly (DCA) for depth sensing of a local area. The DCA includes a transmitter, a receiver, and a controller. The transmitter illuminates a local area with outgoing light in accordance with emission instructions. The transmitter includes a fine steering element and a coarse steering element. The fine steering element deflects one or more optical beams at a first deflection angle to generate one or more first order deflected scanning beams. The coarse steering element deflects the one or more first order deflected scanning beams at a second deflection angle to generate the outgoing light projected into the local area. The receiver captures one or more images of the local area including portions of the outgoing light reflected from the local area. The controller determines depth information for one or more objects in the local area based in part on the captured one or more images.
    Type: Application
    Filed: January 9, 2020
    Publication date: May 21, 2020
    Inventors: Michael Hall, Qing Chao, Byron Taylor, Xinqiao Liu
  • Publication number: 20200145593
    Abstract: Methods and systems for quantizing a physical quantity, such as light, are provided. In one example, an apparatus comprises an analog-to-digital (A/D) converter configured to generate raw digital outputs based on performing at least one of: (1) a first quantization operation to quantize a physical stimulus within a first intensity range based on a first A/D conversion relationship, or (2) a second quantization operation to quantize the physical stimulus within a second intensity range based on a second A/D conversion relationship; and a raw output conversion circuit configured generate a refined digital output based on a raw digital output obtained from the A/D converter and at least one predetermined conversion parameter. The at least one conversion parameter compensates for a discontinuity between the first A/D conversion relationship and the second A/D conversion relationship.
    Type: Application
    Filed: November 1, 2019
    Publication date: May 7, 2020
    Inventors: Wei GAO, Andrew Samuel BERKOVICH, Song CHEN, Tsung-Hsun TSAI, Xinqiao LIU
  • Patent number: 10608101
    Abstract: Embodiments relate to a stacked photo sensor assembly where two substrates are stacked vertically. The two substrates are connected via interconnects at a pixel level to provide a signal from a photodiode at a first substrate to circuitry on a second substrate. The circuitry on the second substrate performs operations that were conventionally performed on first substrate. More specifically, charge storage of the first substrate is replaced with capacitors on the second substrate. A voltage signal corresponding to the amount of charge in the first substrate is generated and processed in the second substrate. By stacking the first and second substrates, the photo sensor assembly can be made more compact while increasing or at least retaining the photodiode fill factor of the photo sensor assembly.
    Type: Grant
    Filed: January 3, 2018
    Date of Patent: March 31, 2020
    Assignee: FACEBOOK TECHNOLOGIES, LLC
    Inventor: Xinqiao Liu
  • Patent number: 10598546
    Abstract: Two separate schemes are used for detecting light intensity in low light conditions and high light conditions. In high light conditions, two threshold voltages are set and the time between the crossing of a sensor voltage at the two threshold voltages is measured to determine the light intensity in the high light conditions. In low light conditions, a comparator is used to compare the voltage level of the sensor voltage relative to a reference voltage that increase over time. The time when the reference voltage reaches the sensor voltage level is detected to determine the light intensity in the low light conditions.
    Type: Grant
    Filed: May 18, 2018
    Date of Patent: March 24, 2020
    Assignee: FACEBOOK TECHNOLOGIES, LLC
    Inventor: Xinqiao Liu
  • Publication number: 20200075652
    Abstract: In one example, an apparatus comprises: a semiconductor substrate including a plurality of pixel cells, each pixel cell including at least four photodiodes; a plurality of filter arrays, each filter array including a filter element overlaid on each photodiode of the pixel cell, at least two of the filter elements of the each filter array having different wavelength passbands; and a plurality of microlens, each microlens overlaid on the each filter array and configured to direct light from a spot of a scene via each filter element of the each filter array to each photodiode of the each pixel cell.
    Type: Application
    Filed: September 4, 2019
    Publication date: March 5, 2020
    Inventors: Song CHEN, Xinqiao LIU
  • Publication number: 20200068189
    Abstract: In one example, an apparatus comprises: a first photodiode to generate a first charge; a second photodiode to generate a second charge; a quantizer; a first memory bank and a second memory bank; and a controller configured to: control the quantizer to perform a first quantization operation and a second quantization operation of the first charge to generate, respectively, a first digital output and a second digital output, the first and second quantization operations being associated with different intensity ranges; store one of the first digital output or the second digital output in the first memory bank; control the quantizer to perform a third quantization operation of the second charge to generate a third digital output, the third quantization operation being associated with a different intensity range from at least one of the first or second quantization operations; and store the third digital output in the second memory bank.
    Type: Application
    Filed: August 26, 2019
    Publication date: February 27, 2020
    Inventors: Song CHEN, Xinqiao LIU, Lyle David BAINBRIDGE, Andrew Samuel BERKOVICH
  • Patent number: 10574973
    Abstract: A depth camera assembly (DCA) for depth sensing of a local area. The DCA includes a transmitter, a receiver, and a controller. The transmitter illuminates a local area with outgoing light in accordance with emission instructions. The transmitter includes a fine steering element and a coarse steering element. The fine steering element deflects one or more optical beams at a first deflection angle to generate one or more first order deflected scanning beams. The coarse steering element deflects the one or more first order deflected scanning beams at a second deflection angle to generate the outgoing light projected into the local area. The receiver captures one or more images of the local area including portions of the outgoing light reflected from the local area. The controller determines depth information for one or more objects in the local area based in part on the captured one or more images.
    Type: Grant
    Filed: September 6, 2017
    Date of Patent: February 25, 2020
    Assignee: Facebook Technologies, LLC
    Inventors: Michael Hall, Qing Chao, Byron Taylor, Xinqiao Liu
  • Publication number: 20200059589
    Abstract: In one example, a method comprises: exposing a first photodiode to incident light to generate first charge; exposing a second photodiode to the incident light to generate second charge; converting, by a first charge sensing unit, the first charge to a first voltage; converting, by a second charge sensing unit, the second charge to a second voltage; controlling an ADC to detect, based on the first voltage, that a quantity of the first charge reaches a saturation threshold, and to measure a saturation time when the quantity of the first charge reaches the saturation threshold; stopping the exposure of the first photodiode and the second photodiode to the incident light based on detecting that the quantity of the first charge reaches the saturation threshold; and controlling the ADC to measure, based on the second voltage, a quantity of the second charge generated by the second photodiode before the exposure ends.
    Type: Application
    Filed: August 19, 2019
    Publication date: February 20, 2020
    Inventors: Xinqiao LIU, Andrew Samuel BERKOVICH, Song CHEN
  • Publication number: 20200007800
    Abstract: In one example, an apparatus comprises: a plurality of photodiodes, one or more charge sensing units, one or more analog-to-digital converters (ADCs), and a controller. The controller is configured to: enable the each photodiode to generate charge in response to a different component of the incident light; transfer the charge from the plurality of photodiodes to the one or more charge sensing units to convert to voltages; receive a selection of one or more quantization processes of a plurality of quantization processes corresponding to a plurality of intensity ranges; based on the selection, control the one or more ADCs to perform the selected one or more quantization processes to quantize the voltages from the one or more charge sensing units to digital values representing components of a pixel of different wavelength ranges; and generate a pixel value based on the digital values.
    Type: Application
    Filed: June 26, 2019
    Publication date: January 2, 2020
    Inventors: Andrew Samuel BERKOVICH, Xinqiao LIU, Song CHEN, Nicholas Daniel TRAIL, Michael Patrick SCHAUB
  • Publication number: 20200007807
    Abstract: Disclosed herein are techniques for digital imaging. A digital pixel image sensor includes a digitizer in each pixel of a plurality of pixels, where the digitizer digitizes analog output signals from a photodiode of the pixel using a comparator, a global reference ramp signal, and a clock counter. In some embodiments, the comparator includes a pre-charging circuit, rather than a constant biasing circuit, to reduce the power consumption of each pixel. In some embodiments, each pixel includes a digital or analog correlated double sampling (CDS) circuit to reduce noise and provide a higher dynamic range.
    Type: Application
    Filed: September 10, 2019
    Publication date: January 2, 2020
    Inventor: Xinqiao LIU
  • Publication number: 20200007798
    Abstract: In one example, a method comprises: enabling a photodiode to, in response to incident light, accumulate residual charge, and to transfer overflow charge to a first charge storage device and a second charge storage device when the photodiode saturates; disconnecting the second charge storage device from the first charge storage device; enabling the photodiode to transfer the residual charge to the first charge storage device to cause the charge sensing unit to output a first voltage; quantizing the first voltage to generate a first digital value to measure the residual charge; connecting the second charge storage device with the first charge storage device to cause the charge sensing unit to output a second voltage; quantizing the second voltage to generate a second digital value to measure the overflow charge; and generating a digital representation of the incident light intensity based on the first digital value and the second digital value.
    Type: Application
    Filed: June 27, 2019
    Publication date: January 2, 2020
    Inventors: Xinqiao LIU, Song CHEN, Andrew Samuel BERKOVICH
  • Publication number: 20190379848
    Abstract: In one example, an apparatus is provided. The apparatus comprises an image sensor configured to generate a first raw output to represent a first intensity of incident light based on a first relationship, and to generate a second raw output to represent a second intensity of incident light based on a second relationship. The apparatus further comprises a post processor configured to: generate a first post-processed output based on the first raw output and based on the first relationship such that the first post-processed output is linearly related to the first intensity based on a third relationship, and to generate a second post-processed output based on the second raw output and based on the second relationship such that the second post-processed output is linearly related to the second intensity based on the third relationship.
    Type: Application
    Filed: June 5, 2019
    Publication date: December 12, 2019
    Inventors: Andrew Samuel BERKOVICH, Wei GAO, Xinqiao LIU, Song CHEN
  • Publication number: 20190379827
    Abstract: In one example, a method comprises: receiving programming data; determining, based on the programming data, at least one of: an integration period in which a charge storage unit including a floating drain accumulates charge received from a photodiode, or a number of times of sampling the charge; enabling the photodiode to accumulate residual charge, and to transmit overflow charge to the charge storage unit after the photodiode saturates; controlling the charge storage unit to accumulate at least a part of the overflow charge received from the photodiode within the integration period; controlling a quantizer to sample the at least a part of the overflow charge or the residual charge for the number of times to obtain the number of samples; and controlling the quantizer to quantize the number of samples to generate the number of quantization results.
    Type: Application
    Filed: June 10, 2019
    Publication date: December 12, 2019
    Inventors: Andrew Samuel BERKOVICH, Xinqiao LIU
  • Publication number: 20190376845
    Abstract: In one example, an apparatus comprises a photodiode, a charge storage unit, and a processing circuits configured to: transfer overflow charge from the photodiode to the charge storage unit to develop a first voltage; compare the first voltage against a first ramping threshold voltage to generate a first decision; generate, based on the first decision, a first digital value; transfer residual charge from the photodiode to the charge storage unit to develop a second voltage; compare the second voltage against a static threshold voltage to determine whether the photodiode saturates to generate a second decision; compare the second voltage against a second ramping threshold voltage to generate a third decision; generate, based on the third decision, a second digital value; and output, based on the second decision, one of the first digital value or the second digital value to represent an intensity of light received by the photodiode.
    Type: Application
    Filed: June 7, 2019
    Publication date: December 12, 2019
    Inventors: Xinqiao LIU, Song CHEN, Andrew Samuel BERKOVICH, Wei GAO
  • Publication number: 20190379846
    Abstract: In one example, an apparatus comprises: a comparator; a sampling capacitor having a first plate and a second plate. The first plate is coupled with an output of a charge sensing unit that senses charge generated by a photodiode, whereas the second plate is coupled with an input of the comparator. The apparatus further includes a controller configured to: at a first time, set a first voltage across the sampling capacitor based on an output voltage of the charge sensing unit; reset the charge sensing unit to set the first plate at a second voltage and to set the second plate at a third voltage based on the first voltage and the second voltage; compare, using the comparator, the third voltage against one or more thresholds; and generate, based on the comparison result, a quantization result of the output voltage of the charge sensing unit at the first time.
    Type: Application
    Filed: June 4, 2019
    Publication date: December 12, 2019
    Inventors: Song CHEN, Xinqiao LIU, Andrew Samuel BERKOVICH, Wei GAO
  • Publication number: 20190379844
    Abstract: In one example, a method comprises: transmitting a first signal to transfer a first portion of a first charge from a first photodiode to a first charge sensing unit to obtain a first measurement result and transmitting a second signal to transfer a second portion of the first charge from the first photodiode to a second charge sensing unit to obtain a second measurement result. The timing of transmission of the first signal and the second signal are based on the indirect time-of-flight measurement operation. The method further comprises performing the indirect time-of-flight measurement operation based on the first measurement result and the second measurement result; transmitting a third signal to transfer a second charge from a second photodiode to the second charge sensing unit via the first photodiode to obtain a third measurement result; and performing a 2D sensing operation based on the third measurement result.
    Type: Application
    Filed: June 10, 2019
    Publication date: December 12, 2019
    Inventors: Song CHEN, Xinqiao LIU
  • Publication number: 20190379388
    Abstract: Methods and systems for performing analog-to-digital conversion is provided. In one example, an analog-to-digital converter (ADC) circuit comprises a leakage compensation circuit and a quantizer. The leakage compensation circuit is configured to: receive an input signal, the input signal being susceptible to a drift due to a charge leakage; receive a reference signal; and generate a leakage-compensated signal pair to compensate for the charge leakage, wherein the leakage-compensated signal pair comprises one of: (a) a leakage-compensated version of the input signal and the reference signal, (b) the input signal and a leakage-compensated version of the reference signal, or (c) a leakage-compensated version of the input signal and a leakage-compensated version of the reference signal. The quantizer is configured to perform a leakage-compensated quantization of the input signal based on the leakage-compensated signal pair to generate a digital output representing the input signal.
    Type: Application
    Filed: February 26, 2019
    Publication date: December 12, 2019
    Inventors: Wei GAO, Andrew Samuel BERKOVICH, Xinqiao LIU, Song CHEN
  • Publication number: 20190378872
    Abstract: In one example, an apparatus comprises: a semiconductor substrate including a front side surface, a first photodiode to generate a first charge, a second photodiode to generate a second charge, a barrier layer between the first photodiode and the second photodiode and configured to control flow of the second charge from the second photodiode to the first photodiode, and a drain region to store the first charge and at least a first part of the second charge. The apparatus further comprises a gate on the front side surface over a first channel region between the first photodiode and the drain region to control the flow of the first charge and the at least the first part of the second charge to the drain region, and a second channel region to conduct at least a second part of the second charge away from the barrier layer when the second photodiode saturates.
    Type: Application
    Filed: June 7, 2019
    Publication date: December 12, 2019
    Inventors: Song CHEN, Xinqiao LIU
  • Publication number: 20190363118
    Abstract: Methods and systems for performing light measurement are disclosed. In one example, an apparatus comprises an array of pixel cells, each pixel cell of the array of pixel cells configured to perform a light measurement operation and to generate a digital output of the light measurement operation. The apparatus further includes a peripheral circuit configured to: receive a pixel array programming map including programming data targeted at each pixel cell of the array of pixel cells, and configure the light measurement operation at the each pixel cell based on the programming data targeted at the each pixel cell. The apparatus further includes an image processor configured to generate an image frame based on the digital outputs of at least some of the array of pixel cells.
    Type: Application
    Filed: May 23, 2019
    Publication date: November 28, 2019
    Inventors: Andrew Samuel BERKOVICH, Xinqiao LIU, Richard Andrew NEWCOMBE, Song CHEN, Wei GAO