Glass substrate, line scanning optical sensors, lighting strips
Principle of Operation
- Miniature cameras are positioned in the top two corners of the substrate.
- Illuminated border or reflective borders on the opposing three sides project a uniform field of infrared light slightly above the glass surface.
- Touch occurs when a finger or object block the light from the cameras.
- The controller processes the optical information and calculates the X,Y coordinates.
- Functions with scratches and surface wear
- Touch activated by bare finger, gloved finger, or stylus
- Transmission is typically >90%
- Moving liquids or solid contaminants may cause false touches or non-function until completely removed
- Requires a bezel design to house the edge positioned camera system
- System thickness is typically 3.5 mm in addition to the thickness of the glass
- Touch occurs slightly above the actual surface
- Limited to 2 resolvable points with 2 cameras; 3 or more resolvable points with 4 cameras