Patent ID: 8451253
Filing Date: 2013-05-28
Classification: G06F

Abstract:
1. An apparatus for acquiring object image of a pointer, the apparatus being suitable for an optical touch system and being used for acquiring an object image of a pointer when the pointer interacts with a touch surface of the optical touch system, the apparatus comprising: an image sensor used for sensing an image of the touch surface; and a processing circuit electrically coupled to the image sensor, wherein when the pointer approaches the touch surface, the processing circuit acquires an image information from a sensed image, and the processing circuit compares at least a part of the image information of the sensed image with a first threshold value, so as to determine a comparison range, the processing circuit further acquires a second threshold value according to the image information in the comparison range, and the processing circuit compares the image information in the comparison range with the second threshold value, so as to acquire an object image of the pointer, the second threshold value is lower than the first threshold value.