摘要 |
A method and system for determining the location of an object touching a touch pad. A light source is used to provide a light beam and a plurality of reflecting surfaces are disposed along an edge of the touch pad to partially reflect the light beam in order to provide a light sheet over the touch pad, such that the reflected intensity varies monotonously along the edge. A detector structure is disposed on the opposite edge to measure the light intensity of the light sheet, part of which is blocked when the object touches the touch pad. The reduction in the measured light intensity is used to calculate the location of the touching object in one direction. A second light sheet and a corresponding detector structure can be used to determine the location of the touching object in a different direction.
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