Prophesee

Prophesee Sa

Centre National De La Recherche Scientifique

Institut National De La Sante Et De La Recherche Medicale

Prophesse

Pixium Vision, Universite Pierre Et Marie Curie

Chronocam

Daniel Matolin

Christoph Posch

Thomas Finateu

Xavier Lagorce

Benjamin R Benosman

Christian Bouvier

Denis Bourke

Massimiliano Giulioni

Lagorce Xavier

A pixel circuit is provided for use in an event sensor. In one implementation, the pixel circuit includes a photosensitive element configured to generate a current signal in response to brightness of light impinging on the photosensitive element, a first N-type transistor, a second N-type transistor, a first P-type transistor including a gate connected to a first bias voltage, a second P-type transistor including a gate connected to a second bias voltage, the second bias voltage being an adjustable DC bias voltage that is adjusted according to at least one of a sensed temperature or a fabrication process variation of the pixel circuit, and a voltage output that varies in response to the brightness of light impinging on the photosensitive element. An adjustment of the second bias voltage causes a DC level of the voltage output to shift up or down without changing the overall gain of the pixel circuit. The pixel circuit may also include one or more additional N-type transistors for increasing performance by optimizing contrast sensitivity. The pixel circuit may further include a converter, a capacitor electrically coupled to the converter, and an amplifier electrically coupled to the capacitor. Further, the pixel circuit may be implemented in a stacked wafer configuration and one or more interconnects between wafers.

Event sensor pixel with sensitivity and dynamic range optimization

The present disclosure generally relates to image sensors and methods for image sensing. More specifically, and without limitation, this disclosure relates to systems and methods for providing super-pixels, and implementing and using image sensors with super-pixels. In one implementation, an image sensor includes a plurality of super-pixels. Each super-pixel may include a first photosensitive element; a detector electrically connected to the first photosensitive element and configured to generate a trigger signal when an analog signal proportional to brightness of light impinging on the first photosensitive element matches a condition; a second photosensitive element; an exposure measurement circuit electrically connected to the second photosensitive element and configured to convert an analog signal proportional to brightness of light impinging on the second photosensitive element to a digital signal; and a logic circuit electrically connected to the detector and the exposure measurement circuit and configured to enable the exposure measurement circuit in response to the trigger signal and to disable the exposure measurement circuit when the digital signal is read out from the exposure measurement circuit.

Image sensor with a plurality of super-pixels

A pixel circuit is provided for use in an image sensor. The pixel circuit includes a photosensitive element configured to generate a current signal in response to brightness of light impinging on the photosensitive element, and a converter configured to receive the current signal from the photosensitive element and generate a voltage signal based on the received current signal. The pixel circuit also includes a capacitor electrically coupled to the converter in series and configured to receive the voltage signal from the converter, and an amplifier electrically coupled, at an input, to the capacitor in series and configured to generate, at an output, an amplified signal based on an output signal from the capacitor, wherein there is no feedback between the output and the input of the amplifier. Further, the pixel circuit includes a reset device configured to reset the amplifier in response to a trigger signal being generated.

Pixel circuit including an open-loop amplifier with well controlled gain for event-based vision sensor and method of controlling thereof

Embodiments of the present disclosure include an event-based image sensor and an event filtering method for use with an event-based image sensor. The event-based image sensor comprises a plurality of pixel circuits forming a pixel array, each pixel circuit comprising a photoreceptor circuit configured to generate a photoreceptor signal derived from a photocurrent generated by a light impinging on a light-sensitive element of the photoreceptor circuit, and a detector configured to detect a change in the photoreceptor signal and to generate an event in response to the detected change in the photoreceptor signal. The event-based image sensor further includes a processing chain and an event filter that is configured to receive the generated event and to accept the received event based on a plurality of conditions. The plurality of conditions include a condition that the received event is part of a previously unaccepted event trail, the event trail comprising a plurality of successive events having a same polarity and separated by time intervals each shorter than a time threshold.

Event filtering method for operating an event-based image sensor

An image sensor includes a plurality of pixels, each pixel including a photosensitive element, and a photo-signal converter adapted to provide, on a first output, a current signal linearly proportional to the intensity of light impinging on the photosensitive element and to provide, on a second output, a voltage signal logarithmic with the intensity of light impinging on the photosensitive element. Each pixel further includes a detector adapted to generate a trigger signal when a signal of the detector proportional to the voltage signal of the second output of the photo-signal converter exceeds a threshold, and a light-to-time converter adapted to measure and encode, in the time domain, light intensity on the photosensitive element. A light-to-time conversion cycle may be initiated by the light-to-time converter in response to receipt of the trigger signal.

Systems and methods for asynchronous, time-based image sensing

An event-based image sensor is provided that includes a plurality of pixel circuits. Each pixel circuit includes a photoreceptor circuit with a light-sensitive element configured for delivering at an output a photoreceptor current, an analog bus, and a bank of current memory cells connected to the analog bus. An output of the photoreceptor circuit is selectively connected to the analog bus. Each current memory cell is adapted to store an electric current flowing in the analog bus and to deliver an electric current stored within the current memory cell. Each pixel circuit may further include a current comparator including a current sign detector connected to the analog bus and configured for comparing a value of a compared electric current resulting from a difference between the photoreceptor current and a previous photoreceptor current stored in a current memory cell. At least one storage cell may also be provided that has a state conditioned by the output of the current sign detector.

Event-based image sensor and operating method thereof

The invention relates to pixel circuit and an operating method thereof, comprising&#x2014;a front-end circuit () comprising a single photodiode (PD) and having an output (), said front-end circuit () being configured for delivering on said output a photoreceptor signal derived from a light exposure of said single photodiode (PD);&#x2014;a transient detector circuit () configured for detecting a change in said photoreceptor signal delivered on said output ();&#x2014;an exposure measurement circuit () configured for measuring said photoreceptor signal delivered on said output () upon detection by the transient detector circuit () of a change in the photoreceptor signal. The invention also relates to an image sensor comprising a plurality of pixel circuits

Dynamic, single photodiode pixel circuit and operating method thereof

A circuit includes a selection circuit electrically coupled to pixels of a line of an event vision sensor. The selection circuit is configured to receive an activation signal from an active pixel of the line, generate an acknowledge signal in response to receiving the activation signal, and send the acknowledge signal to the pixels of the line. The circuit also includes a control circuit that is electrically coupled to a pixel having a largest distance to the selection circuit among the pixels of the line. The control circuit is configured to receive the acknowledge signal from the selection circuit, and generate a process-reading signal in response to receiving the acknowledge signal. The circuit also includes an interface circuit electrically coupled to the pixels of the line and configured to cause a reset of the selection circuit, the control circuit, and the pixels of the line after receiving the process-reading signal.

Event array readout control of event-based vision sensing

The invention relates to pixel circuit and an operating method thereof, comprising The invention also relates to an image sensor comprising a plurality of pixel circuits.

A pixel cell circuit comprises an electrode, one or more main photosensitive elements electrically coupled to the electrode for outputting a stimulation signal to the electrode responsive to light illumination, and a shunt arrangement comprising a shunt switch electrically coupled in parallel across the one or more photosensitive elements, and a control arrangement operatively coupled to the shunt switch and configured for placing the shunt switch in an open state responsive to incident light received at the pixel cell and placing the shunt switch in a closed state if no incident light is received at the pixel cell.

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Freital, Germany

Daniel Matolin