How the VKB works?
Step 1: Template creation (Projection Module)
A template of the desired interface is projected onto the adjacent interface surface. The template is produced by illuminating a specially designed, highly efficient holographic optical element with a red diode laser. Note: the template serves only as a reference for the user and is not involved in the detection process. In a fixed environment, the template can just as easily be printed onto the interface surface.
Step 2: Reference plane illumination (Micro-illumination ModuleTM)
An infra-red plane of light is generated just above, and parallel to, the interface surface. This light is invisible to the user and hovers a few millimeters above the surface. When the user touches a key position on the interface surface light is reflected from this plane in the vicinity of the key and directed towards the sensor module.
Step 3: Map reflection coordinates (Sensor Module)
Reflected light from user interactions with the interface surface is passed through an infra-red filter and imaged on to a CMOS image sensor in the sensor module. Custom hardware embedded in the sensor chip (the Virtual Interface Processing CoreTM) then makes a real-time determination of the location of the reflected light. The processing core can track multiple reflection events simultaneously and can thus support both multiple keystrokes and overlapping cursor control inputs.