摘要 |
When an object touches a touch panel, a projection light source projects a predetermined image including image information and forms an object image having the image information on a surface of the object. An image sensor captures a reflection image including the object image. Then, an angle is calculated according to an image location of the object in the reflection image and a relative position of predetermined axis, and a distance between the object and the image sensor is calculated by comparing the predetermined image with the location, size and/or phase of the image information of the reflection image so as to determine a coordinate of the object on the touch panel according to the angle and the distance.
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