Infra-red sensing delivers multi-touch, gesture detection, claims gains over capacitive technology

March 21, 2013 // By Paul Buckley
Dialog Semiconductor plc is moving into the touchscreen sensor market with the launch of the SmartWave DA8901 Multi-Touch Integrated Circuit (MTIC).

The MTIC claims to be the world’s first chip to enable FlatFrog’s market proven Planar Scatter Detection (PSD) Touch in high volume consumer devices. Using in-lens infrared light, the FlatFrog PSD Touch system can detect and track multiple touches, gestures and pressures from gloved hands, stylus and other objects, providing a more natural true-touch user experience at performance levels surpassing the latest capacitance-based solutions, but at a fraction of the cost.

MTIC is suitable for laptops, All-in-One PCs, Ultrabooks and monitors, and is optimized for display types between 11 and 36 inches. It is also designed to meet Microsoft Windows 8 and Intel’s Ultrabook touch requirements.

Supporting up to 40 simultaneous touches, the MTIC uses the proven principles of FlatFrog’s patented Planar Scatter Detection (PSD) Touch technology to detect changes in infrared light injected into the cover lens of the display. As users touch the glass surface, scattered light is detected by multiple infrared receivers. The resulting signals are received by the MTIC where they are amplified and pre-filtered before being converted to the digital domain. The data is then subjected to advanced signal processing using the MTIC’s integrated detector engine – based on the ARM Cortex M0 processor – which is then used as a basis to provide the touch co-ordinates to the main device processor.

A single MTIC can drive up to twelve infrared LED/emitter pairs directly. A typical Ultrabook, tablet or All-in-One PC would contain a number of MTICs configured in a master/slave arrangement catering for a flexible number of screen sizes up to 36 inches. PSD Touch works with any display type and with either a glass or plastic cover lens. Unlike projected capacitive (procap) touch technology, which is widely deployed today in smartphones and tablets, the system provides full edge-to-edge industrial design with 100% optical clarity because there are no expensive ITO layers to impede the light from the display reaching the eye. This also