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.

Abstract: In one example, an apparatus comprises: a photodiode to generate a charge in response to light within an exposure period having a first duration; a charge sensing unit to accumulate at least a part of the charge within the exposure period; a quantizer; and a controller to: determine, using the quantizer and within a measurement period having a second duration, whether a first quantity of the at least a part of the charge accumulated at the charge sensing unit exceeds a threshold, and a time it takes for the first quantity to exceed the threshold, wherein the first duration and the second duration are individually programmable; and based on whether the first quantity exceeds the threshold, output a first value representing the time or a second value representing a second quantity of the charge generated by the photodiode within the exposure period to represent an intensity of the light.

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.

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.

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.

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.

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.

Abstract: Examples of a wearable device are disclosed. In one example, the wearable device may include an optical network, a first sensor and a second sensor coupled with the optical network, and a processor. The first sensor and a second sensor are configured to generate, respectively, first sensor data and second sensor data related to different physical measurements, and to transmit the first sensor data and the second sensor data to the optical network. The processor is coupled with the optical network and configured to: receive at least one of the first sensor data or the second sensor data from the optical network; and determine output content of the wearable device based on the at least one of the first sensor data or the second sensor data.

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.

Abstract: A photo sensor includes a plurality of pixel blocks, each including one or more anchor pixels and one or more non-anchor pixels. The anchor pixels produce first sensor signals and the non-anchor pixels produce second sensor signals. An amplifier circuit amplifies the first and second sensor signals. A variable bit-depth analog to digital converter (ADC) circuit quantizes amplified versions of the first sensor signals into first digitized sensor signals with a first bit-depth. The ADC circuit also quantizes amplified versions of the second sensor signals into second digitized sensor signals with a second bit-depth that is lower than the first bit depth. The second bit-depth may be selected based on anchor pixel statistics derived from the one or more first digitized sensor signals.

Abstract: A photo sensor array is divided up into multiple blocks that are operated with different exposure times. A prediction algorithm is used to predict the overall light brightness of each block and determine the exposure time of each block. Each block may also include memory to store the exposure time for the pixels in the block as well as analog-to-digital resolution for the block.

Abstract: A sensor assembly for determining one or more features of a local area is presented herein. The sensor assembly includes a plurality of stacked sensor layers. A first sensor layer of the plurality of stacked sensor layers located on top of the sensor assembly includes an array of pixels. The top sensor layer can be configured to capture one or more images of light reflected from one or more objects in the local area. The sensor assembly further includes one or more sensor layers located beneath the top sensor layer. The one or more sensor layers can be configured to process data related to the captured one or more images. A plurality of sensor assemblies can be integrated into an artificial reality system, e.g., a head-mounted display.

Abstract: A light field camera capturing one or more light field frames including intensity and angle information of received light. The light field camera includes an array of pixels, a liquid crystal layer overlaying the array of pixels, and a controller. The controller controls, at each time instant, one or more voltages applied to the liquid crystal layer. The controller adjusts, based on the one or more voltages, the liquid crystal layer to control amounts of light at one or more angles transmitted through the liquid crystal layer and captured by the array of pixels as a light field frame. The controller can determine depth information based on the captured one or more light field frames.

Abstract: A method for monolithically fabricating a light field sensor with an array of microlens. Each microlens is formed directly on a surface including a plurality of pixels of the light field sensor formed on a wafer. The manufacturing system performs a preparation of the surface including the plurality of pixels formed on the wafer. The manufacturing system deposits a layer of photoresist on the surface of the wafer. The manufacturing system performs a patterning on the deposited layer to form one or more blocks of cured photoresists. The manufacturing system performs a thermal curing of the one or more blocks of uncured photoresists to form an array of microlens of the light field sensor. Each microlens covers at least one of the plurality of pixels of the light field sensor formed on the wafer.

Abstract: In one example, an apparatus comprises: a photodiode configured to generate charge in response to incident light within an exposure period; and a quantizer configured to perform at least one of a first quantization operation to generate a first digital output or a second quantization to generate a second digital output, and output, based on a range of an intensity of the incident light, one of the first digital output or the second digital output to represent the intensity of the incident light. The first quantization operation comprises quantizing at least a first part of the charge during the exposure period to generate the first digital output. The second quantization operation comprises quantizing at least a second part of the charge after the exposure period to generate the second digital output.

Abstract: A waveguide display includes a light source, a scanning mirror assembly, an output waveguide, and a controller. The light source emits image light. The scanning mirror assembly scans the image light as scanned image light to particular locations in accordance with scanning instructions. The output waveguide includes an input area and an output area. The output waveguide receives the scanned image light emitted from the scanning mirror assembly at the input area, and output expanded image light from a portion of the output area, the location of the portion of the output area based in part on a direction of the scanned image light output from the scanning mirror assembly. The controller generates the scanning instructions and provides the scanning instructions to the scanning mirror assembly.

Abstract: In one example, an apparatus comprises: an image sensor comprising an array of pixel cells, each pixel cell including a photodiode and circuits to generate image data, the photodiodes formed in a first semiconductor substrate; and a controller formed in one or more second semiconductor substrates that include the circuits of the array of pixel cells, the first and second semiconductor substrates forming a stack and housed within a semiconductor package. The controller is configured to: determine whether first image data generated by the image sensor contain features of an object; based on whether the first image data contain the features of the object, generate programming signals for the image sensor; and control, based on the programming signals, the image sensor to generate second image data.

Abstract: In one example, an apparatus includes an array of pixel cells and a peripheral circuit. Each pixel cell of the array of pixel cells includes: a memory to store pixel-level programming data and measurement data, and light measurement circuits configured to, based on the pixel-level programming data from the control memory, perform a light measurement operation to generate the measurement data, and to store the measurement data at the data memory. The peripheral circuit is configured to: receive a pixel array programming map including pixel-level programming data targeted at each pixel cell; extract the pixel-level programming data from the pixel array programming map; and transmit the pixel-level programming data to each pixel cell of the array of pixel cells for storage at the memory of the each pixel cell and to individually control the light measurement operation and a generation of the measurement data at the each pixel cell.

Abstract: Examples of an apparatus are disclosed. In some example, an apparatus may include a photodiode, a first charge storage unit configured to store charges generated by the photodiode, the first charge storage unit having a first capacity; and a second charge storage unit configured to store charges generated by the photodiode, the second charge storage unit having a second capacity greater than the first capacity. The apparatus may further include an analog-to-digital converter (ADC) circuit configured to measure a first quantity of charges stored in the first charge storage unit and a second quantity of charges stored in the second charge storage unit, and to generate a digital output representing an intensity of light incident on the photodiode based on a first count representing the first quantity of charges or a second count representing the second quantity of charges.

Abstract: In one example, a pixel cell comprises a first photodiode to generate a first charge and a second photodiode to generate a second charge. The pixel cell may include a charge sensing unit shared between the first photodiode and the second photodiode. The charge sensing unit may include a charge storage device to temporarily store a charge and convert the charge to a voltage. The pixel cell may include a quantizer to quantize the voltage output by the charge sensing unit, and a memory to store the quantization output. Depending on an operation mode, the first charge and the second charge can be controlled to flow simultaneously to the charge sensing unit for read out, or can be controlled to flow separately to the charge sensing unit for read out. The pixel cell further includes a memory to store a quantization result of the first charge and the second charge.