Abstract: A method for determining the compatibility of a working surface with an optical mouse having an optical sensor including (a) using the optical sensor to sense the optical characteristics of the working surface, (b) using a judging circuit to judge the compatibility of the working surface with the optical mouse according to the optical characteristics sensed by the optical sensor, (c) using the judging circuit to generate a judging signal according to the result obtained in step (b).

Abstract: The present invention provides an image scrolling system for scrolling an image frame contained in a window which is displayed in a monitor of the system. The image scrolling system comprises a scrolling signal generator for generating scrolling signals to perform scrolling of the image frame. Each of the scrolling signals is first converted into a corresponding two-dimensional vector which is then converted to a displacement vector. The displacement vector is added with a current coordinate of the image frame displayed within the window to obtain a next coordinate, and the image frame is scrolled to the next coordinate.

Abstract: The present invention discloses a pointing device for scrolling a screen image. The pointing device comprises a chassis, a housing having an opening on its top mounted on the chassis, a vertical sensor installed on the chassis below the opening, a plurality of horizontal sensors installed on the chassis beside the vertical sensor, and a control stick vertically installed inside the opening of the housing comprising a top end and a bottom end. The bottom end of the control stick is in contact with the vertical sensor whereas the top end of the control stick protrudes from the opening of the housing and can be horizontally moved within a predetermined angle with respect to the bottom end of the control stick serving as its center. The pointing device further comprises a plate horizontally installed at the bottom end of the control stick with its bottom side positioned above the horizontal sensors.