Patent ID: 8659561

Claim:
A method of sensing touch on a display device having an optical sensing frame comprising: emitting first light from a sensor module; receiving a first reflection at the sensor module; emitting second light from a waveguide; receiving a second reflection at the waveguide; and if a touch is made on an optical sensing frame: detecting that reflections of the first and the second light are interfered, and determining a change in the quantity of the first and second reflection received to determine the touch, wherein a first determination of the position of the touch is made by triangulation of the touch based on the first reflection; wherein a second determination of a position along an axis parallel to a length of the waveguide of the touch is made based on the second reflection, and wherein: if a multi touch is made, determining actual positions of the multi touch based on the first and the second determination, wherein the first determination comprises actual position information of the multi touch and ghost position information, the actual position information and the ghost position information each including a first axis information and a second axis information, the method further comprising: comparing the first axis information and the second determination to determine the actual positions of the multi touch.