Inside the touch screen frame, there is a set of phototransistor receivers and LED emitters placed opposite each other, creating a grid of invisible infrared light. When a touch occurs (e.g., by a finger), it blocks the infrared grid. One or more phototransistors detect the loss of light and send a signal to determine the X and Y coordinates.
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Inside the touch screen frame, there is a set of phototransistor receivers and LED emitters placed opposite each other, creating a grid of invisible infrared light. When a touch occurs (e.g., by a finger), it blocks the infrared grid. One or more phototransistors detect the loss of light and send a signal to determine the X and Y coordinates.
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