Infrared (Grid) (IR)
Glass or acrylic substrate, wrap-around-bezel frame, LED matrix
Principle of Operation
- LEDs create a grid of X and Y infrared light beams projected above the display and are detected by photoreceptors on the opposite edge.
- Touch occurs when a finger or stylus blocks the beam from reaching light detectors.
- Controller’s constant X and Y axis scanning detects blocked light detectors and triangulates touch location.
- Functions with scratches and surface wear
- Touch activated by bare finger, gloved hand, or a wide stylus
- Transmission typically 90% to 92%
- Solid contaminants, moving liquids or obstructions may cause a false touch and may create dead zones until completely removed
- Does not scale easily (new layout required)
- Beam spacing limits accuracy and stylus width
- Touch occurs slightly above the actual surface resulting in possible touch parallax or an unintended touch response
- Requires a bezel design to house the LEDs and detectors
- Limited to 2 or 3 resolvable touches