Patent ID: 8125449

Claim:
A highly sensitive movable touchpad for a digital apparatus having a cursor, comprising: a slidable template having a front surface exposed and a back surface with a specific texture; a limiting member, for limiting the slidable template within a moving range and providing the slidable template with a low friction, surrounding the slidable template and exposing central portion of the front surface of the slidable template; an optical displacement detecting device, located below the slidable template, for detecting movement of the slidable template, including: a light source, for emitting light beams to illuminate the back surface of the slidable template; an image sensor for receiving speckle images formed by light beams scattered by the back surface; and an image processor for obtaining relative location, moving direction and speed of the slidable template by comparison of the speckle images; and a control unit for controlling corresponding movement of the cursor of the digital apparatus according to the relative location, moving direction and speed obtained from the image processor.