Abstract: A system and a method for sensing the location of a remote object relative to a base object involve integrating inductive loop antennas with variable loop density into the base object and utilizing the antennas to transmit energy to and receive energy from an LC resonant circuit that is integrated into the remote object. The amplitude of a signal generated by the inductive loop antennas in response to energy received from the LC circuit identifies the location of the LC circuit relative to the antennas. Preferably, the sensing system is integrated into an electronic percussion instrument, where the keys of the instrument are formed with overlapping inductive loop antennas and the mallets used to activate the keys are formed with LC resonant circuits integrated into the mallet heads.

Abstract: A system and method for detecting, measuring the intensity of, and determining the location of a deformation of a membrane. In one embodiment, the intensity and location of membrane deformations is used as control input to a sound generation system that simulates the sound of a drum. The disclosed system and method may be capable of responding to distinct simultaneous deformations of the membrane.

Abstract: A keyboard system in a keyboard controlled musical instrument includes a pair of spaced apart electrode members and a pickup movable in the space intermediate the electrode members. Respective voltages are impressed on the electrodes to establish an electric field therebetween and the voltage impressed on the movable pickup is a function of its position relative to the two electrodes. The pickup is actuated by the playing key which contacts a resilient, yieldable stop. The force with which the playing key is depressed is measured by sensing when the key is fully depressed, initiating a count at that point and counting a predetermined period. At the end of the predetermined period the voltage on the pickup is detected which gives an indication of the amount of overtravel of the key beyond its normal depressed position. This detected voltage is used to alter the quality of the tones produced by the musical instrument.

Abstract: A calibration system for the keyboard of an electronic musical instrument. Compression of the key causes an output signal to be generated which varies in accordance with the amount of key depression. When the key is depressed to a nominally fully depressed position, the system stores an offset value relating to the difference between the actual output signal at this point and an expected reference output signal which would occur if the keyboard were perfectly adjusted from a mechanical standpoint. The offset value is stored in the memory and added to the key output signal during the normal operate mode of the instrument so that the output signal is adjusted in accordance with the offset value stored during the calibrate mode.

Abstract: A keyboard system for an electronic musical instrument of the keyboard type, such as an electronic organ, synthesizer or electronic piano. The keyboard is responsive to the velocity with which the key is depressed and controls the tone generation circuitry to produce tones of higher amplitudes for higher key depression velocities. The keyboard also includes an aftertouch control whereby further depression of the key past its normal limit against a compressible medium, such as a foam rubber or felt washer, alters the quality of the tone produced. For example, the aftertouch control could be used to vary vibrato, change pitch, change decay, and the like. A pickup for each key is positioned in an electric field set up between two electrodes, and the voltage impressed on the pickup will change depending on the position of the pickup within the field as determined by the amount of depression of the key.