Finally, a Princeton University start-up was on hand in the iZone prototype area with a 3D Gesture technology it calls SpaceTouch, a low cost 3D capacitance sensing technology that can be added to any surface to deliver what it calls “out-of-plane” gesture sensing, greater than 50cm above the display surface. The group is targeting large displays in particular, and even spoke of installing them on shop windows to control DOOH (digital out of home) signs inside a closed store.
Top on the list of benefits is very low cost, low power and robustness in a variety of high ambient light conditions, compared to traditional camera based gesture technologies. Conventional capacitance sensing works in the “few centimeter” range, but Princeton group developed high signal to noise ratio sensing at plus 50cm using just a few electrodes “peripherally placed”, according to the group. To get there, it uses a custom IC along with the front-end sensors, plus readout boards, gesture recognition firmware and a standard USB interface that helps speed integration with almost any system.
This is the second year Princeton made it to the IZone, and it told us that, compared with the 23-inch demonstration last year, both the design and configuration of the oscillating plane has been substantially improved. This led to reducing the number of sensors to just four and they are now formed by copper strips and embedded in the edges of a 42-inch commercial TV display. There is also room for improvement in the sensing distance and the group has achieved sensing now up to about one full metre in some apps. The gesture set has also been expanded beyond simple cursor control and now includes four swipes (left, right, up and down), clicks (at different locations on the display) and zoom (both in/out). The Python-based programming framework is useful in multiple applications including DOOH (shop windows) or video gaming apps. For the prototype, Princeton integrated its readout board and four sensors into a 42-inch LCD TV. It uses a USB cable to send the decoded gesture commands to a PC for content control of the displayed image.
Going forward, the group sees the technology mounted into a frame for mounting on any display surface, and this is where the DOOH community may get very interested, as it affords low cost interface control of a display by being mounted on a shop window. or virtually any other surface.
