Electro-optical mouse with means to separately detect the changes in contrast ratio in X and Y directions

Claim 1

An electro-optical mouse, comprising a first signal pick-up device for detecting, in an X direction, changes in contrast ratio of a reflective surface caused by passage of the first signal pick-up device over a grid of lines on the reflective surface in the X direction and second pick-up device for detecting, in a Y direction, changes in contrast ratio of the reflective surface caused by passage of the second signal pick-up device over said grid of lines in Y direction, said first and second signal pick-up devices comprising light source means including an LED light source for projecting light onto said reflective surface, lens means including a cylindrical lens for amplifying light reflected from said surface, reflector means including a reflector for transmitting light from said cylindrical lens to a detector, said detector including means for generating an electrical signal sensed changes in contrast ratio in order to enable a computer to accurately control the movement of a cursor on a visual display the central axes of said cylindrical lenses being oriented at right angles to each other to separately amplify changes in said contrast ratio on the X and Y direction each lens amplifying only the line crossing of said grid of lines which are disposed parallel to the central axis thereof.