Patent ID: 7283122

Claim:
An input device for scrolling an image relative to an image display screen along perpendicular axes, the device comprising: a housing including an upper surface having at least one opening and a lower surface adapted for movement along a tracking surface; and a scroll wheel assembly provided within the housing, the scroll wheel assembly including a finger-engagable rotatable member that is positioned within the opening, the finger-engagable rotatable member being endlessly rotatable about a first axis extending within the housing and the finger-engagable rotatable member being pivotally movable about a second axis, the first axis being substantially perpendicular to the second axis; and a tilt sensing system that determines when the finger-engagable rotatable member is pivoted about the second axis relative to the housing, the tilt sensing system including a tilt contact member extending between the second axis and the lower surface; two contact switches located on opposite sides of the tilt contact member; and a return to center device configured to return the finger-engagable rotatable member to a neutral position, the return to center device including a flexible blade having a proximal end and a distal end, the proximal end being operatively connected to the finger-engagable rotatable member.