Patent ID: 7689381

Claim:
A sensing system adapted to sense a pointer and calculate a location of the pointer, comprising: a panel having a first plane and a first area located at the first plane, the first area being quadrangular and having a first boundary, a second boundary, a third boundary and a fourth boundary which are connected in order; a reflective element disposed at the first boundary and located on the first plane, the reflective element having a second plane substantially perpendicular to the first plane, the second plane being a reflective plane and mirroring the first area to form a second area; an image sensor disposed at a corner at which the third boundary and the fourth boundary intersects and located on the first plane, a sensing range of the image sensor covering the first area and the second area; and a processor electrically connected to the image sensor; wherein when the pointer approaches the first area and the pointer is mirrored by the reflective element to form a first mirror image such that the pointer and the first mirror image is in the sensing range of the image sensor and when a portion of the pointer adjacent to the first area, a portion of the first mirror image adjacent to the second area and the image sensor are not colinear, the image sensor senses the pointer and the first mirror image and the processor calculates the location of the pointer.