Stmicroelectronics Gmbh

Arnaud Deleule

Xiaoyong Yang

Rui Xiao

Darin K Winterton

Kalyan-Kumar Vadlamudi-Reddy

John E Kvam

A time of flight range detection device includes a laser configured to transmit an optical pulse into an image scene, a return single-photon avalanche diode (SPAD) array, a reference SPAD array, a range detection circuit coupled to the return SPAD array and the reference SPAD array, and a laser driver circuit. The range detection circuit in operation determines a distance to an object based on signals from the return SPAD array and the reference SPAD array. The laser driver circuit in operation varies an output power level of the laser in response to the determined distance to the object.

Adaptive laser power and ranging limit for time of flight sensor

The present disclosure is directed to a system and method of controlling a facial recognition process by validating preconditions with a ranging sensor. The ranging sensor transmits a ranging signal that is reflected off of a user's face and received back at the ranging sensor. The received ranging signal can be used to determine distance between the user's face and the mobile device or to determine the reflectivity of the user's face. Comparing the distance to a range of distances corresponding to normal operation of the device or normal reflectivities associated with human skin tones can reduce the number of false positive activations of the facial recognition process. Furthermore, a multiple zone ranging sensor can produce a face depth map that can be compared to a stored face depth map or can produce a reflectivity map that can be compared to a stored face reflectivity map to further increase power efficiency and device security.

Power and security adjustment for face identification with reflectivity detection by a ranging sensor

A device includes a time-of-flight ranging sensor configured to transmit optical pulse signals and to receive return optical pulse signals. The time-of-flight ranging sensor processes the return optical pulse signals to sense distances to a plurality of objects and to generate a confidence value indicating whether one of the plurality of objects has a highly reflective surface. The time-of-flight sensor generates a range estimation signal including a plurality of sensed distances and the confidence value. The image capture device includes autofocusing circuitry coupled to the time-of-flight sensor to receive the range estimation signal and configured to control focusing based upon the sensed distances responsive to the confidence value indicating none of the plurality of objects has a highly reflective surface. The autofocusing circuitry controls focusing independent of the sensed distances responsive to the confidence value indicating one of the objects has a highly reflective surface.

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Cupertino, CA, United States of America

Arnaud Deleule