Patent ID: 8525814

Claim:
A method of distinguishing multiple touch points, applied to an optical touch system which comprises a panel for indicating a first touch point and a second touch point thereon and a camera unit for capturing an image relative to the first touch point and the second touch point, the image having a first dark area and a second dark area corresponding to the first touch point and the second touch point respectively, said method comprising the following steps of: (a) judging whether the first dark area and the second dark area are a first single dark area currently; (b) if the judging in the step (a) is YES, judging whether the first dark area and the second dark area are a second single dark area at a previous time; (c) if the judging in the step (b) is YES, determining a position of the first dark area and a position of the second dark area according to a union dark area width of the first single dark area and a union dark area width of the second single dark area; (d) determining coordinates of the first touch point and the second touch point according to the position of the first dark area and the position of the second dark area; (e) if the judging in the step (a) is NO, judging whether the first dark area and the second dark area are a third single dark area at the previous time; and (f) if the judging in the step (e) is YES, determining the positions of the first dark area and the second dark area by comparing current area information of the first touch point and the second touch point with previously-stored area information of the first touch point and the second touch point.