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: 10491877
    Abstract: A depth camera assembly (DCA) determines distances between the DCA and objects in a local area within a field of view of the DCA. The DCA projects a series of sinusoidal patterns into the local area DCA and captures images of the sinusoidal patterns via a sensor. Each pixel of the augmented sensor includes a plurality of charge bins, and charge accumulated by a photodiode of a pixel during different time intervals (e.g., times when different sinusoidal patterns are emitted) is stored in a different charge storage bin. Charge may be retrieved from different charge storage bins to determine depth from the DCA.
    Type: Grant
    Filed: December 21, 2017
    Date of Patent: November 26, 2019
    Assignee: Facebook Technologies, LLC
    Inventors: Michael Hall, Qing Chao, Xinqiao Liu
  • Publication number: 20190355138
    Abstract: A depth camera assembly (DCA) determines depth information. The DCA projects a dynamic structured light pattern into a local area and captures images including a portion of the dynamic structured light pattern. The DCA determines regions of interest in which it may be beneficial to increase or decrease an amount of texture added to the region of interest using the dynamic structured light pattern. For example, the DCA may identify the regions of interest based on contrast values calculated using a contrast algorithm, or based on the parameters received from a mapping server including a virtual model of the local area. The DCA may selectively increase or decrease an amount of texture added by the dynamic structured light pattern in portions of the local area. By selectively controlling portions of the dynamic structured light pattern, the DCA may decrease power consumption and/or increase the accuracy of depth sensing measurements.
    Type: Application
    Filed: May 17, 2019
    Publication date: November 21, 2019
    Inventors: Michael Hall, Xinqiao Liu, Zhaoming Zhu, Rajesh Lachhmandas Chhabria, Huixuan Tang, Shuochen Su, Zihe Gao
  • Publication number: 20190348460
    Abstract: An apparatus is provided. The apparatus includes a semiconductor substrate including 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, wherein the first photodiode, the barrier layer, and the second photodiode form a stack. The apparatus further includes a floating drain and one or more gates including: a first gate portion on the semiconductor substrate and a second gate portion extending from the front side surface through the first photodiode and reaching the barrier layer. The first gate portion is configured to conduct a first signal to control flow of charge from the first photodiode to the floating drain, and the second gate portion is configured to conduct a second signal to control the barrier layer to control the flow of the second charge.
    Type: Application
    Filed: May 8, 2019
    Publication date: November 14, 2019
    Inventors: Song CHEN, Xinqiao LIU
  • Patent number: 10466779
    Abstract: An eye tracking system includes an event camera. The event camera includes an event sensor and a controller. The event sensor includes a plurality of photodiodes that asynchronously output data values corresponding to relative intensity changes of light reflected from a user's eyes. The controller populates an event matrix based in part on data values asynchronously received from the event sensor and positions of photodiodes associated with the received data values over a first time period. The controller populates a change matrix based in part on a threshold intensity value and the photodiodes associated with the received data values over the first time period, and generates an image of the user's eyes for the first time period using the event matrix and the change matrix. The eye tracking system uses the image of the user's eyes to determine eye tracking information indicating positions, orientations and/or movement of the user's eyes.
    Type: Grant
    Filed: July 24, 2017
    Date of Patent: November 5, 2019
    Assignee: FACEBOOK TECHNOLOGIES, LLC
    Inventor: Xinqiao Liu
  • Publication number: 20190327439
    Abstract: In one example, an apparatus comprises: a photodiode, a charge storage unit, and an analog-to-digital converter (ADC) circuit. In a first mode, the ADC circuit can compare a first voltage representing a quantity of the overflow charge stored at the charge storage unit against a first ramping voltage to generate a first decision; and obtain, based on the first decision output, a first digital value. In a second mode, the ADC circuit can compare a second voltage representing a quantity of residual charge stored in the photodiode against a second ramping voltage to generate a second decision, and obtain, based on the second decision, a second digital value. The ADC circuit can determine, based on one of the first decision output or the second decision output, whether the photodiode saturates, and output one of the first digital value or the second digital value to represent an intensity of incident light.
    Type: Application
    Filed: April 11, 2019
    Publication date: October 24, 2019
    Inventors: Song CHEN, Xinqiao LIU, Wei GAO, Andrew Samuel BERKOVICH
  • Publication number: 20190319061
    Abstract: In one example, an apparatus comprises: a first photodiode configured to convert a first component of light to a first charge, second photodiode configured to convert a second component of the light to a second charge; and an interface circuit configured to: perform a first quantization and a second quantization of the first charge to generate, respectively, a first result and a second result, the first quantization and the second quantization being associated with different light intensity ranges; provide one of the first result or the second result to represent an intensity of the first component of a pixel; perform the first quantization and the second quantization of the second charge to generate, respectively, a third result and a fourth result; and provide one of the third result or the fourth result to represent an intensity of the second component of the pixel.
    Type: Application
    Filed: April 15, 2019
    Publication date: October 17, 2019
    Inventors: Xinqiao LIU, Song CHEN
  • Publication number: 20190320105
    Abstract: Methods and systems for reconstructing images from sensor data are provided. In one example, a method comprises: receiving input data generated by photodiodes each associated with a channel having a target wavelength range for photon-to-charge conversion; obtaining, for each channel, a plurality of channel coefficients, the plurality of channel coefficients being configured to, when combined with the input data to generate channel output data for the each channel, increase a main component of the channel output data contributed by a part of the incident light within the target wavelength range of the each channel with respect to a crosstalk component of the channel output data contributed by a part of the incident light out of the target wavelength range; and generating, for the each channel, the channel output data based on combining the input data with the plurality of channel coefficients to reconstruct an image for the each channel.
    Type: Application
    Filed: April 16, 2019
    Publication date: October 17, 2019
    Inventors: Huixuan TANG, Song CHEN, Xinqiao LIU
  • Publication number: 20190305020
    Abstract: Examples of image sensors are provided. In one example, a pixel cell comprises a first semiconductor die, a sampling capacitor, and a second semiconductor die which may include the sampling capacitor. The first semiconductor die includes a photodiode and a charge sensing device. The second semiconductor die forms a stack with the first semiconductor die, the second semiconductor die including an interface circuit coupled with the photodiode, the charge sensing device, and the sampling capacitor. The interface circuit is configured to: enable the photodiode to accumulate charge responsive to incident light within a integration period; transfer the charge from the photodiode to the charge sensing device; perform, using the sampling capacitor, a sample-and-hold operation to convert the charge in the charge sensing device into a voltage; and generate a digital output based on the voltage to represent an intensity of the incident light received by the photodiode.
    Type: Application
    Filed: March 29, 2019
    Publication date: October 3, 2019
    Inventors: Xinqiao LIU, Song CHEN
  • Publication number: 20190285468
    Abstract: Methods and systems for performing analog-to-digital conversion are proposed. In one example, An analog-to-digital converter (ADC) comprising a quantizer, the quantizer having a first quantization resolution for a first quantization operation subrange and a second quantization resolution for a second quantization operation subrange. At least one of the first quantization resolution or the first quantization operation subrange is programmable. At least one of the second quantization resolution or the second quantization operation subrange is programmable. The quantizer is configured to: receive an input voltage; and based on whether the input voltage belongs to the first quantization operation subrange or to the second quantization operation subrange, quantize the input voltage at the first quantization resolution or at the second quantization resolution to generate a digital output.
    Type: Application
    Filed: January 16, 2019
    Publication date: September 19, 2019
    Inventors: Andrew Samuel BERKOVICH, Xinqiao LIU
  • Patent number: 10419701
    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: Grant
    Filed: December 19, 2017
    Date of Patent: September 17, 2019
    Assignee: FACEBOOK TECHNOLOGIES, LLC
    Inventor: Xinqiao Liu
  • Publication number: 20190273114
    Abstract: Methods and systems for light sensing are provided. In one example, an apparatus comprises and an array of pixel cells and a controller. Each pixel cell of the array of pixel cells includes a photodiode configured to generate charges upon receiving incident light and a capacitor configured to accumulate the charges generated by the photodiode. The controller is configured to: start an exposure period to accumulate the charges at the pixel cells; and based on a determination that the quantity of charges accumulated by the at least one pixel cell exceeds a pre-determined threshold: end the exposure period to cause the capacitors of the array of pixel cells to stop accumulating the charges, generate an output pixel value for each pixel cell based on the charges accumulated at the capacitor of the each pixel cell within the exposure period; and provide the output pixel values to generate an image frame.
    Type: Application
    Filed: February 26, 2019
    Publication date: September 5, 2019
    Inventor: Xinqiao LIU
  • Publication number: 20190230306
    Abstract: Examples of an apparatus are disclosed. In some example, an apparatus may include an array of digital pixel cells, each digital pixel cell including a photodiode and a memory device to store a digital output generated based on charge generated by the photodiode in an exposure period. The apparatus may also include an image processor configured to: receive first digital outputs from the memory devices of a first set of digital pixel cells of the array of digital pixel cells; determine, from the first set of digital pixel cells, a second set of digital pixel cells of which the first digital outputs satisfy one or more pre-determined conditions; identify, based on the second set of digital pixel cells, a third set of digital pixel cells; receive the second digital outputs generated by the third set of digital pixel cells; and perform image processing operations based on the second digital outputs.
    Type: Application
    Filed: January 23, 2019
    Publication date: July 25, 2019
    Inventor: Xinqiao LIU
  • Publication number: 20190172868
    Abstract: Methods and systems for image sensing are provided. In one example, an apparatus comprises a semiconductor substrate comprising a light incident surface to receive light, a first pinned photodiode, and a second pinned photodiode, the first pinned photodiode and the second pinned photodiode forming a stack structure in the semiconductor substrate along an axis perpendicular to the light incident surface, the stack structure enabling the first pinned photodiode and the second pinned photodiode to, respectively, convert a first component of the light and a second component of the light to first charge and second charge. The apparatus further comprises one or more capacitors formed in the semiconductor substrate and configured to generate a first voltage and a second voltage based on, respectively, the first charge and the second charge.
    Type: Application
    Filed: December 5, 2018
    Publication date: June 6, 2019
    Inventors: Song CHEN, Xinqiao LIU, Byron TAYLOR
  • Patent number: 10277838
    Abstract: An imaging array and method for fabricating the same are disclosed. The imaging array includes a semiconductor substrate having a plurality of VIS pixel sensors and a plurality of SWIR readout circuits fabricated therein. An insulating layer is deposited on the semiconductor substrate. The insulating array has wells overlying the SWIR pixel sensors. A plurality of SWIR photodiodes are deposited in the wells. Each SWIR photodiode is located in a corresponding one of the wells and is connected by an electrically conducting path with the SWIR readout circuit underlying the SWIR photodiode. An electrically conducting transparent electrode overlying the SWIR photodiodes is connected to each of the SWIR photodiodes.
    Type: Grant
    Filed: July 28, 2016
    Date of Patent: April 30, 2019
    Assignee: BAE Systems Imaging Solutions Inc.
    Inventors: Xinqiao Liu, Boyd Fowler
  • Patent number: 10274758
    Abstract: Examples of an apparatus are disclosed. In some examples, an apparatus may comprise a first waveguide configured to propagate light originated from a light source, a first modulator coupled with the first waveguide, and a first sensor coupled with the first modulator. The apparatus may further comprise a second waveguide coupled with the first waveguide to form a propagation path for the light between the light source and a receiver device, a second modulator coupled with the second waveguide, and a second sensor coupled with the second modulator. The first modulator is configured to modulate the light propagating in the first waveguide based on sensor data from the first sensor, and the second modulator is configured to modulate the light propagating in the second waveguide based on sensor data from the second sensor, to enable the receiver device to obtain the sensor data.
    Type: Grant
    Filed: March 27, 2018
    Date of Patent: April 30, 2019
    Assignee: FACEBOOK TECHNOLOGIES, LLC
    Inventor: Xinqiao Liu
  • Patent number: 10237481
    Abstract: An imaging device operates as an event camera. The device includes an event sensor and a controller. The sensor comprises a plurality of photodiodes that asynchronously output data values corresponding to relative intensity changes within a local area. The controller populates an event matrix based in part on data values asynchronously received from the sensor and positions of photodiodes associated with the received data values over a first time period. The controller populates a change matrix based in part on a threshold intensity value and the photodiodes associated with the received data values over the first time period, and generates an image for the first time period using the event matrix and the change matrix.
    Type: Grant
    Filed: April 18, 2017
    Date of Patent: March 19, 2019
    Assignee: Facebook Technologies, LLC
    Inventors: Richard Andrew Newcombe, Michael Hall, Xinqiao Liu, Steven John Lovegrove, Julian Straub
  • Publication number: 20190075281
    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: September 6, 2017
    Publication date: March 7, 2019
    Inventors: Michael Hall, Qing Chao, Byron Taylor, Xinqiao Liu
  • Publication number: 20190058058
    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: Application
    Filed: January 3, 2018
    Publication date: February 21, 2019
    Inventor: Xinqiao Liu
  • Publication number: 20190056264
    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: Application
    Filed: May 18, 2018
    Publication date: February 21, 2019
    Inventor: Xinqiao Liu
  • Publication number: 20190057995
    Abstract: Embodiments relate to a stacked photo sensor assembly where two substrates that 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. 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: Application
    Filed: November 1, 2017
    Publication date: February 21, 2019
    Inventor: Xinqiao Liu