04736191 is referenced by 313 patents and cites 18 patents.

A cursor control device (10) is provided which has a touch pad (14) formed of individual conductive plates (16) forming sectors of a circle. A user's touch on a dielectric layer (18) overlying the plates (16) is detected by individually charging and discharging each of the sector plates in a sequential manner to determine the increased capacitance, if any, of each sector plate. A microprocessor assigns each of the sector plates a relative X and Y weighting as a function of its angular position in the touch pad which are combined with the individual plate capacitance readings to calculate the relative X and Y position of the touch with respect to the origin (28) of the touch pad. Cursor control signals proportional to the relative X and Y values, plus a Z value proportional to the area of touch, if desired, are provided to the keyboard (12) of a displaying computer. The touch pad (14) can be effectively integrated into a computer keyboard by positioning it immediately beneath the space bar (25) of the keyboard so that it can be accessed by the thumb of the user without requiring the user to move his or her hand from the keyboard.

Title
Touch activated control method and apparatus
Application Number
6/762049
Publication Number
4736191
Application Date
August 2, 1985
Publication Date
April 5, 1988
Inventor
Paul W Schick
Madison
WI, US
Karl E Matzke
916 Castle Pl., Madison, 53703
WI, US
Agent
Isaksen Lathrop Esch Hart & Clark
Assignee
Karl E Matzke
WI, US
IPC
H03K 17/975
H03K 17/96
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