Facebook Technologies, LLC

Meta Platforms Technologies, LLC

Song Chen

Xinqiao Liu

Andrew Samuel Berkovich

Wei Gao

Tsung-Hsun Tsai

Nicholas Daniel Trail

Lyle David Bainbridge

Michael Patrick Schaub

Richard Andrew Newcombe

Byron Taylor

Huixuan Tang

Karina Singer

The present disclosure provides a privacy control circuit including an array of pixel cells having a first output data path and a second output data path, the first output data path including a one-time data protection circuitry, a sensor communication interface communicatively coupled to the first output data path, an on-sensor processor coupled to the second output data path and communicatively attached to the sensor communication interface, and a data register communicatively attached to the sensor communication interface.

On-sensor data guardian

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.

Programmable pixel array

One example described herein includes the digital image sensor having a pixel cell with a photodiode and a quantizer circuit coupled to the pixel cell. The quantizer circuit includes a charge storage device that generates a voltage based on electric charge from the photodiode. The quantizer circuit also includes a single-input comparator that can switch from a first output state to a second output state in response to a ramp signal provided by a ramp generator. The quantizer circuit further includes a memory switch that can cause a counter value from a digital counter to be stored in a digital memory in response to the single-input comparator switching from the first output state to the second output state. The counter value can serve as a digital pixel value associated with the pixel cell.

Digital image sensor using a single-input comparator based quantizer

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.

Pixel sensor having adaptive exposure time

In some examples, a sensor apparatus comprises: a pixel cell configured to generate a voltages, the pixel cell including a photodiode configured to generate charge in response to incoming light, and a charge storage device to convert the charge to a voltage; an integrated circuit configured to: determine a first captured voltage converted by the charge storage device during a first time period; compare the first captured voltage to a threshold voltage value; and in response to determining that the first captured voltage meets or exceeds the threshold voltage value: determine first time data corresponding to the first time period; and prevent the charge storage device from further generating a charge; and an analog-to-digital converter (ADC) configured to generate a digital pixel value based on the first captured voltage, and a memory to store the digital pixel value and the first time data.

Digital pixel sensor having reduced quantization operation

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.

Pixel sensor having multiple photodiodes and shared comparator

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.

Digital pixel with extended dynamic range

In one example, an apparatus comprises an array of pixel cells, each pixel cell including: a photodiode to generate a charge in response to incident light, a charge sensing unit configured to generate a voltage based on the charge, a quantizer configured to generate a digital output based on quantizing the voltage, and an in-pixel memory configured to store the digital output. The apparatus further includes a bus interface, an off-array frame memory, and a frame memory controller configured to: control the frame memory to receive, via the set of parallel interconnects, the digital outputs from the in-pixel memory of each pixel cell of the array of pixel cells; store the digital outputs in the frame memory; fetch the digital outputs from the frame memory; and transmit the digital outputs to a host device via the bus interface.

Pixel sensor having hierarchical memory

An apparatus comprises a first photodiode, a second photodiode, 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; and perform, using the quantizer, a second quantization operation of the second charge to generate a second digital output.

Pixel sensor having shared readout structure

In one example, an apparatus comprises: multiple distinct sets of photodiodes, wherein each set of photodiodes includes one or more photodiodes, one or more charge sensing units, and a controller. The controller is configured to: transfer charge generated by the one or more photodiodes in response to a different component of incident light to the one or more charge sensing units in order to convert the charge to voltages; perform one or more quantization processes of a plurality of quantization processes corresponding to a plurality of intensity ranges, wherein the one or more quantization processes quantizes 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 at least some of the digital values.

Pixel sensor having multiple photodiodes

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.

Global shutter image sensor

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.

Image sensor post processing

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.

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.

Multi-photodiode pixel cell

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.

Growing community of inventors

Redmond, WA, United States of America

Song Chen