Musical keyboard using planar coil arrays

A keyboard apparatus for use in a musical instrument, comprising:

• a plurality of key structures arranged in a row, each structure having a planar key member pivotally mounted on a reference plane and capable of moving when depressed towards or away from said plane, each of said key members having secured to a surface thereof a magnetic field effecting member,
• a plurality of static members each associated with one of said key structures and each underlying said associated planar key member, and each having located on a surface thereof a planar coil configuration, whereby when said associated key member is moved towards said associated static member the inductance of said planar coil member is varied, and
• common circuit means coupled to said planar coil configuration with each planar coil configuration coupled to said common circuit means by lines of the same effective length, with said common circuit means operative to provide an output for each of said keys according to the position of the same.

A key apparatus for use in a musical keyboard comprising:

• a pivotable planar key member having a first end pivotally mounted on a reference plane and second movable end, and having positioned on a surface thereof a first magnetic field effecting member,
• a second planar member rigidly positioned on said reference plane and underlying said first magnetic field effecting member and having positioned on a surface facing said surface of said key member a planar coil configuration having an inductance,
• a third planar member having located on a surface a second magnetic field effecting member and positionally adjustable on said reference plane to move towards or away from said second planar member to thereby adjust said inductance whereby when said key member is moved into proximity with said second planar member, the inductance of said planar coil varies according to the position of both said key member and said third planar member, whereby said third planar member can be positionally adjusted in accordance with a desired inductance change to accurately determine the position of said key member with respect to said second planar member.