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.
Pros and Cons
|Functions with scratches and surface wear||Moving liquids or solid contaminants may cause false touches or non-function until completely removed|
|Touch activated by bare finger, gloved finger, or stylus||Requires a bezel design to house the edge positioned camera system|
|Scalable||System thickness is typically 3.5 mm in addition to the thickness of the glass|
|Transmission is typically > 90 %||Touch occurs slightly above the actual surface|
|Limited to two resolvable points with two cameras; three or more resolvable points with four cameras|
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