Inventor
PURCELL ALEXANDER M
US12 patents
Patents
12 patentsUS5065145ANov 12, 1991
Method and apparatus for producing signals corresponding to the position of a cursor
SUMMAGRAPHICS CORP95 citations95
US4999462AMar 12, 1991
Position determining and digitizing method and device
SUMMAGRAPHICS CORP82 citations95
US5004871AApr 2, 1991
Digitizer stylus having side switch
SUMMAGRAPHICS CORP34 citations92
US5001306AMar 19, 1991
Distributed optical fiber device for digitizer tablet
SUMMAGRAPHICS CORP34 citations92
US4977315ADec 11, 1990
Liquid crystal position determining system and wand device
SUMMAGRAPHICS CORP23 citations92
US5153386AOct 6, 1992
Digitizer tablet with illuminable working surface
SUMMAGRAPHICS CORP29 citations91
US4952757AAug 28, 1990
Low-power electromagnetic digitizer tablet
SUMMAGRAPHICS CORP49 citations91
US4943689AJul 24, 1990
Backlit digitizer tablet
SUMMAGRAPHICS CORP36 citations91
US5173793ADec 22, 1992
Liquid crystal shutter for backlit digitizer
SUMMAGRAPHICS CORP9 citations73
US5109141AApr 28, 1992
Digitizer stylus with z-axis side control
SUMMAGRAPHICS CORP13 citations73
US5061828AOct 29, 1991
Digitizer stylus with Z-axis side pressure control
SUMMAGRAPHICS CORP18 citations73
US5028744AJul 2, 1991
Digitizer with illuminable working surface
SUMMAGRAPHICS CORP12 citations72