Some tricks goes from smartphones to PCs

Time-of-flight sensors and IR-based facial recognition are increasingly present in smartphones for environment scanning, user detection and authentication.

Now such a combination is coming to laptops. STMicroelectronics publicizing the integration of its FlightSense Time-of-Flight (ToF) ranging sensor behind the cover glass of a laptop. Leveraged by Intel Context Sensing, the sensor can monitor the user’s presence in front of their PC and offer instant data security while reducing power consumption as the laptop is left unattended.

When the user leaves, the ToF sensor detects their absence and immediately locks the system and directs it into the Windows Modern-Stand-by low-power state, improving security and reducing power consumption. The ToF sensor then enters a low-power autonomous mode, scanning the scene for the user returning while keeping the PC asleep to save power. When the user returns, the ToF sensor wakes the PC and automatically enables facial recognition to log in without waiting for a key press or mouse movement.

The ST patented algorithm used in the system can distinguish an immobile person sitting in front of a PC from an inanimate object, such as a chair, without relying on video analytics from the power-hungry and potentially intrusive webcam.

Traditional infra-red (IR) ranging sensors rely on reflected signal strength and cannot directly measure distance. Unlike ToF sensors, the effectiveness and accuracy of these IR sensors are affected by the reflectivity of the target.