Pressure sensitive conductor and method of manufacturing the same Patent #: 4292261
ApplicationNo. 06/399695 filed on 07/19/1982
US Classes:428/215, Absolute thicknesses specified178/17B, Tape control178/18.03, Writing digitizer pad341/5, For X or Y coordinate determination (e.g., stylus-pad)428/323, Including a second component containing structurally defined particles428/329, Iron oxide or aluminum oxide428/900, MAGNETIC FEATURE428/913, MATERIAL DESIGNED TO BE RESPONSIVE TO TEMPERATURE, LIGHT, MOISTURE, ETC.428/914TRANSFER OR DECALCOMANIA
ExaminersPrimary: Herbert, Thomas J. Jr.
Attorney, Agent or Firm
International ClassesG06F 3/033 (20060101)
H01B 1/22 (20060101)
AbstractA pressure-sensitive, conductive elastic sheet for use in a graphics digitizing tablet through which various letters or figures can be detected, the characteristics of which are such that the contact pressure is almost constant irrespective of contact area or increases with increasing contact area. The pressure-sensitive sheet according to the present invention comprises a silicon rubber in which a number of coarse, ferromagnetic, conductive metal particles with a diameter of 30 to 150 micron are mixed with a number of fine, ferromagnetic, conductive metal particles with a diameter of 10 micron or less or 50 micron or less at a predetermined proportion in such a manner that the coarse particles are aligned vertically through the interior thereof and the fine particles are dispersed near at least one surface thereof. To properly align the particles, the sheet is allowed to set within a uniform magnetic field.