Patent ID: 9235293
Filing Date: 2016-01-12
CPC Classification: G06F

Claim Text:
1. An optical touch device comprising: an indication plane having four corners; only two image sensing units disposed at two of the four corners of the indication plane diagonal to each other, respectively, the two of the four corners defining a diagonal line connected therebetween; and a processing unit electrically connected to the two image sensing units; wherein when two touch points are performed on the indication plane, the processing unit determines whether the two touch points are located at opposite sides of the diagonal line, respectively, according to images sensed by the two image sensing units; once the two touch points are located at opposite sides of the diagonal line, respectively, the processing unit determines that there is no ghost point immediately without performing any additional processes of identifying ghost point and then calculates and outputs coordinates of the two touch points immediately after determining that the two touch points are located at opposite sides of the diagonal line; once the two touch points both are located at one side of the diagonal line and are performed on the indication plane simultaneously, the processing unit identifies the two touch points as real touch points and then calculates and outputs coordinates of the two touch points according to brightness of the two touch points sensed by the two image sensing units; once the two touch points both located at one side of the diagonal line and are not performed on the indication plane simultaneously, the processing unit identifies the two touch points as real touch points and then calculates and outputs coordinates of the two touch points according to appearance sequence of the two touch points sensed by the two image sensing units; once the two touch points both are located at one side of the diagonal line and are both moving on the indication plane, the processing unit identifies the two touch points as real touch points and then calculates and outputs coordinates of the two touch points according to the moving trajectories of the two touch points.