Touch-responsive tone envelope control circuit for electronic musical instruments

Claim 2

In an electronic musical instrument having a plurality of keys, a touch-responsive keying system comprising: a plurality of touch-responsive means, each for generating a touch-responsive DC voltage that corresponds to an intensity of depression of a respectively associated one of said playing keys, a plurality of charge storage elements, one being provided and connected to each of said touch-responsive means for storing said touch-responsive DC voltage, a plurality of keyer circuits, each corresponding to one of said charge storage elements and having a control terminal connected thereto, a plurality of diodes, one being provided for each of said means, voltage supply means for providing a predetermined DC voltage, means for connecting said predetermined DC voltage to said plurality of diodes, and connecting means at each keyer circuit responsive to the depression of an associated key for connecting said predetermined DC voltage through a corresponding one of said diodes to a respectively associated control terminal thereby permitting said predetermined DC voltage to be supplied to a control terminal when said predetermined voltage is greater than said touch-responsive DC voltage for a particular key.

Claim 3

A touch-responsive keying system according to claim 1, in which each of said charge storage elements is connected to a discharge element when its associated key is not fully depressed.

Claim 4

A touch-responsive keying system according to claim 1, in which said predetermined DC voltage is substantially equal to the touch-responsive DC voltage generated and stored by a weak key depression intensity.

Claim 5

A touch-responsive keying system according to claim 1, in which sAid predetermined DC voltage is substantially equal to the touch-responsive DC voltage generated and stored by a strong key depression intensity.

Claim 6

A touch-responsive keying system according to claim 1, in which there are provided two voltage supply means, one of which provides a predetermined DC voltage substantially equal to the touch-responsive DC voltage generated and stored by a weak key depression intensity and the other of which provides a predetermined DC voltage substantially equal to the touch-responsive DC voltage generated and stored by a strong key depression intensity, and means for selecting either one of said two predetermined DC voltages for connection to a respectively corresponding control terminal.

Claim 7

A touch-sensitive keying system for an electronic musical instrument comprising a plurality of individual key actuated circuits, each having: a coil adapted to generate an induced electromotive force responsive to the actuation speed of a playing key, a capacitor effectively connected to said coil for storing the induced electromotive force, a discharging resistor, a key-actuated changeover switch, one fixed contact of the changeover switch being connected to said resistor for effecting an electrical connection of said resistor across said capacitor during release of an associated key and another fixed contact of the changeover switch being connected to a unidirectional conducting element, a keyer circuit, having a control terminal connected to said capacitor, for controlling the output characteristics of the musical instrument in association with the intensity of depression of the individual playing key by applying an input to said control terminal of the keyer circuit with the charge stored on the capacitor; and a voltage supply means connected to the unidirectional conducting element for supplying a preselected DC voltage to the control terminal upon full depression of the key via said changeover switch whereby said preselected DC voltage is supplied to the control terminal if it is greater than the voltage stored in said capacitor.

Claim 8

A touch-sensitive keying system for an electronic musical instrument comprising a plurality of individual key actuated circuits, each having: a coil adapted to generate an induced electromotive force responsive to the actuation speed of a playing key, a capacitor effectively connected to said coil for storing the induced electromotive force, a discharging resistor, a key-actuated changeover switch, one fixed contact of the changeover switch being connected to said resistor for effecting an electrical connection of said resistor across said capacitor during release of an associated key and another fixed contact of the changeover switch being connected to a unidirectional conducting element, a keyer circuit, having a control terminal connected to said capacitor, for controlling the output characteristics of the musical instrument in association with the intensity of depression of the individual playing key by applying an input to said control terminal of the keyer circuit with the charge stored on the capacitor; and a voltage supply means connected to the unidirectional conducting element for supplying a preselected DC voltage to the control terminal upon full depression of the key via said changeover switch whereby said preselected DC voltage is supplied to the control terminal if it is greater than the voltage stored in said capacitor.

Claim 9

A touch-sensitive keying system according to claim 6, in which said keyer circuit includes: a pair of active elements, each having a control electrode, a cathode electrode and an anode electrode, a pair of input and output terminals, each of said control electrodes being commonly connected via a separate resistor to the capacitor, each of said cathode electrodes being connected to an individual input terminal for receiving an input tone signal of different footages, and each of said anode electrodes being connected to an individual output terminal to derive the output signal thereat through an individual load.

Claim 10

A touch-responsive keying system according to claim 7, in which said active elements are field effect transistors.

Claim 11

A touch-responsive keying system according to claim 6, in which said voltage supply means includes a voltage divider and a voltage selecting switch combined therewith.

Claim 12

A touch-responsive keying system according to claim 6 in which said voltage supply means includes a potentiometer to permit continuous preselection of a DC voltage to said control terminal.