Feature

ToF sensor gesture recognition and distance measurement

The competing proximity sensing technologies start with simple infrared and ultrasonic sensors, gradually working up to more complex sensor systems such as stereoscopic video cameras with neural networks.

01/04/2019 14:19:04

These technologies have limitations, and while artificial intelligence may be needed to implement complex tasks such as object recognition and tracking for autonomous vehicles, the technology is overkill for dispensing paper towels and soap.

One of the alternatives to consider for proximity sensing are Time-of-Flight, or ToF sensors. ToF sensors measure distance to a target object by timing the round trip of photons as they travel from the sensor to the object and back. To date, it’s been difficult to implement ToF designs quickly and at low cost, but new generations of highly integrated and inexpensive ToF sensors now make it possible to bring highly accurate touchless sensing to lower cost designs.

Early proximity sensors

The Polaroid SX-70 instant film camera, introduced in 1972, incorporated many innovative technologies. However, one of the most influential technologies that Polaroid introduced in their SX-70 camera was the Sonar Autofocus System, which first appeared in the Polaroid SONAR OneStep camera announced in 1978 (Fig 1). The SONAR Autofocus System employed an innovative ultrasonic transducer to both transmit and receive the ultrasonic ranging pulse.

Read the full article in the April issue of DPA

Written By Sophia Bell

Sophia Bell is the Group Editor of DPA, Connectivity, and PBSI. She joined the team in 2020 as Assistant Editor after achieving a First-Class Honours BA in English Literature and Film Studies from the University of East Anglia. In her current role, she leads the editorial strategy, driving digital growth and ensuring each title continues to deliver trusted, relevant insight for engineering and manufacturing professionals.