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.

Abstract: An apparatus comprises a first photodiode, a second photodiode, a charge sensing unit, a quantizer, a memory, and a controller configured to: set a first exposure period in which the first photodiode generates a first charge; set a second exposure period in which the second photodiode generates a second charge, the second exposure period being set based on the first exposure period and at least one of: a first time associated with a read out operation of the memory to a second apparatus, or a second time associated with a quantization operation by the quantizer; perform, using the quantizer, the first quantization operation of the first charge to generate a first digital output; store the first digital output in the memory; perform, using the quantizer, a second quantization operation of the second charge to generate a second digital output; and store the second digital output in the memory.

Abstract: A depth camera assembly (DCA) optimizes illumination and image capture of a local area to generate depth information of the local area. The DCA determines depth information for a first portion of the local area viewable at a first pose. The DCA is moved from the first pose to a second pose, where a second portion of the local area is viewable and overlaps with the first portion. The overlapping region is not illuminated by the DCA. A non-overlapping portion of the second portion is illuminated, captured, and depth information determined.

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.

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: In one example, an apparatus comprises a plurality of sub-pixels arranged sideway, a shared optical element positioned over the plurality of sub-pixels, the shared optical element being configured to direct light originating from a same location in a scene to each sub-pixel in the plurality of sub-pixels; one or more polarizers positioned between the shared optical element and one or more first sub-pixels of the plurality of sub-pixels and configured to selectively pass one or more components of the light having one or more pre-determined polarization states, to enable the photodiodes of each of the one or more first sub-pixels to generate signals based on intensities of the one or more components; and one or more processors configured to generate polarimetric measurements of the received light based on signals obtained from the photodiodes of the one or more first sub-pixels and polarization properties of the one or more polarizers.

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.

Abstract: In one example, a method comprises: within an integration period: enabling a photodiode of a pixel cell to accumulate charge responsive to incident light, and transferring the charge from the photodiode to a charge storage device of the pixel cell. The method further comprises: performing, using a sampling capacitor, a sample-and-hold operation to convert the charge stored in the charge storage device into a voltage; and generating a digital output based on the voltage to represent an intensity of the incident light received by the photodiode.

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. Different sensor architectures featuring various arrangements of memory and computing devices are described, some of which feature in-memory computing. A plurality of sensor assemblies can be integrated into an artificial reality system, e.g., a head-mounted display.

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.

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.

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 D sensing operation based on the third measurement result.

Abstract: In one example, an apparatus is provided. The apparatus includes a photodiode, a charge sensing unit, an analog-to-digital converter (ADC), and a controller. The controller is configured to: enable the photodiode to generate charge in response to incident light, accumulate at least a portion of the charge as residual charge until the photodiode becomes saturated by the residual charge, and transfer the remaining portion of the charge to the charge sensing unit as overflow charge if the photodiode becomes saturated by the residual charge. The controller is further configured to: generate, using the ADC, a first digital output based on the residual charge; after generating the first digital output, generate, using the ADC, a second digital output based on the overflow charge; and generate a digital representation of an intensity of the incident light based on at least one of the first digital output or the second digital output.

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.

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.

Abstract: A depth estimation system is described capable of determining depth information using two images from two cameras. A first camera captures a first image and a second camera captures a second image, both images including a plurality of light channels. In a first light channel of the plurality of light channels, the system calculates a census transform for each pixel of the first image and a census transform for each pixel of the second image. In a second light channel of the plurality of light channels, the system calculates a census transform for each pixel of the first image and a census transform for each pixel of the second image. The system generates a depth map based in part on the census transforms for each pixel of the first image and the second image in the first light channel and in the second light channel.

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).

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.

Abstract: In one example, a mobile device comprises: a physical link; a plurality of image sensors, each image sensor being configured to transmit image data via the physical link; and a controller coupled to the physical link, whereby the physical link, the plurality of image sensors, and the controller form a multi-drop network. The controller is configured to: transmit a control signal to configure image sensing operations at the plurality of image sensors; receive, via the physical link, image data from at least a subset of the plurality of image sensors; combine the image data from the at least a subset of the plurality of image sensors to obtain an extended field of view (FOV); determine information of a surrounding environment of the mobile device captured within the extended FOV; and provide the information to an application to generate content based on the information.

Abstract: A depth camera assembly (DCA) determines depth information within a local area. The DCA may selectively process a subset of data captured by an imaging sensor and obtained from the imaging sensor, such as pixels corresponding to a region of interest, for depth information. Alternatively, the DCA may limit retrieval of data from the imaging sensor to pixels corresponding to the region of interest from the imaging sensor for processing for depth information. The depth processing may include a semi-global match (SGM) algorithm, and the DCA adjusts a number of neighboring pixels used for determining depth information for a specific pixel based on one or more criteria. In some embodiments, the DCA performs the depth processing by analyzing images from different image sensors using left to right and right to left correspondence checks that are performed in parallel.