Keyboard circuit and method for detecting keyboard circuit
AssigneeCasio Computer Co., Ltd.
InventorYoji Kaneko
Life of this patent
Estimating the term…
Abstract
A keyboard circuit (15) of an electric music instrument includes contact transistors (TRk) having at least three terminals as input/output terminals for state detection for each of a plurality of contacts (14a, 14b, and 14c); and wiring units to the contact transistors (TRk) and the contacts (14a, 14b, and 14c). A selector (Sm) and the wiring unit for each of the plurality of contacts (14a, 14b, and 14c) are arranged to be divided into a plurality of layers in three dimensions. Then, the keyboard circuit (15) detects ON/OFF states for each of the contacts (14a, 14b, and 14c) for which the ON/OFF states change in response to a key-pressing operation for each of a plurality of keys (12) and for which at least one is provided to each of the plurality of keys (12).
Claims8
A keyboard circuit comprising:
- contact units that are provided so as to correspond to a plurality of keys, respectively, the contact units having ON/OFF states that change in response to a key-pressing/key-releasing operation to the plurality of keys;
- elements that are provided for each of the plurality of contact units, wherein each of the elements has at least three input/output terminals and the contact units are connected to any one of the input/output terminals;
- and
- a wiring unit that outputs signals indicating the ON/OFF states of the respective contact units by supplying a switch signal to a remaining one of the input/output terminals of the respective elements, supplying a control signal to another remaining one of the input/output terminals, and supplying to the contact units the switch signal supplied in a time-division manner by way of the control signal.
A method for detecting a keyboard circuit, the keyboard circuit including Ill contact units that are provided so as to correspond to a plurality of keys, respectively, the contact units having ON/OFF states that change in response to a key-pressing/key-releasing operation to the plurality of keys, and (ii) elements that are provided for each of the plurality of contact units, each of the elements having at least three input/output terminals and the contact units being connected to any one of the input/output terminals, the method comprising:
- inputting a switch signal to a remaining one of the input/output terminals of each of the elements;
- inputting a control signal to another remaining one of the input/output terminals;
- and
- outputting a signal indicating the ON/OFF states of the respective contact units by supplying to the contact units the switch signal inputted in a time-division manner by way of the control signal.
Dependencies are inferred from the claim text.