Key speed sensor of electronic instrument
AssigneeRoland Corporation
InventorTadao Kikumoto
Life of this patent
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Abstract
A device for accurately detecting key operation speed with a simple configuration in which a plurality of alternating signals, which have mutually differing phases, is supplied to transmission electrodes. From this, capacitance between reception electrodes and the transmission electrodes is changed by a key pressing operation, and the phases of the alternating signals induced in the reception electrodes are compared and discriminated.
Claims24
A key operation speed detection device for an electronic musical instrument having a plurality of keys comprising:
- one or more reception electrodes, each of the one or more reception electrodes corresponding to a key of the plurality of keys;
- two or more transmission electrodes facing each of the one or more reception electrodes;
- a keyboard device configured to move one of the one or more reception electrodes and the two or more transmission electrodes relative to the other of the one or more reception electrodes and two or more transmission electrodes to change a capacitance between the one or more reception electrodes and the two or more transmission electrodes;
- a signal generation circuit associated with at least some of the plurality of keys, the signal generation circuit configured to generate a plurality of alternating signals, each of the alternating signals having the same period and a different phase from each other, the signal generation circuit configured to supply each of the alternating signals to a respective one of the transmission electrodes to induce a respective detection signal, the signal generation circuit configured to generate a standard phase signal having the same period as the alternating signals;
- and
- a signal processing circuit associated with at least some of the plurality of keys, the signal processing circuit configured to determine a pressing depth of the key based on the standard phase signal and the detection signals, and the signal processing circuit configured to determine an operating speed of the key based on a time interval in which the key passes at least two pressing depths.
A detection device for detecting a key operation of an electronic musical instrument having a plurality of keys, the device comprising:
- one or more reception electrodes, each of the one or more reception electrodes corresponding to a key of the plurality of keys;
- two or more transmission electrodes facing each of the one or more reception electrodes;
- a key element configured to move one of the one or more reception electrodes and the two or more transmission electrodes relative to the other of the one or more reception electrodes and two or more transmission electrodes to change a capacitance between the one or more reception electrodes and the two or more transmission electrodes;
- a signal generation circuit associated with at least some of the plurality of keys, the signal generation circuit configured to generate a plurality of alternating signals, each of the alternating signals having the same period and a different phase from each other, the signal generation circuit configured to supply each of the alternating signals to a respective one of the transmission electrodes to induce a respective detection signal, the signal generation circuit configured to generate a standard phase signal having the same period as the alternating signals;
- and
- a signal processing circuit associated with at least some of the plurality of keys, the signal processing circuit configured to determine a pressing depth of the key based on the standard phase signal and the detection signals.
Dependencies are inferred from the claim text.