Kabushiki Kaisha Kawai Gakki Seisakusho

Yoshiro Nakayama

Hiroshi Kato

Koji Tanaka

Yasuhiko Okuyama

A keyboard type electronic musical instrument wherein tone assignment signals (key depression signals) designated by depressing desired keys of keyboards are transmitted to an electronic circuit block through only one signal line per sort of keyboard as time-divided serial timing signals. The electronic circuit block includes therein a circuit which generates parallel output signals having respectively different timings in correspondence with notes of the keyboards. The parallel timing signals are respectively sent to the corresponding key switches of the keyboards, they are selected by turning 'on' the switches, and they are converted by OR circuits into serial timing signals representative of the selected notes. The serial timing signals are sent to a device for detecting and storing notes or chords, whereupon as in prior arts, a tone signal is generated from the obtained signal indicative of a note or chord by tone signal producing device and it is amplified and provided as an output by a loudspeaker. This time-division control system is applicable to electronic musical instruments having any desired forms of keyboards.

Keyboard type electronic musical instrument

A keyboard type automatic accompanying system wherein information representative of the root note of a chord and the type thereof are detected from key depression signals assigned by depressing a plurality of desired keys of an accompanying keyboard, the detected information are stored, and an automatic chord complying with the particular chord are accompanied. A chord detector comprises in combination a shift register which stores the accompanying key assignment signals therein and which shifts the stored contents cyclically, and a ROM device in which binary information indicative of the basic forms of chord names and the types of chords are stored. Outputs of the shift register are applied to the ROM device, and the type and the root note of the chord are detected in one shift cycle of the shift register, so that the circuit arrangement is simplified, that the detecting time is shortened and that the key response rate is enhanced. On the basis of the information representative of the root note of the chord and the type thereof, an auto-chord tone assignment signal is formed by an ACC signal generator. The signal is timed in a chord tone generator by a rhythm pulse transmitted from a rhythm pulse generator, and becomes an automatic chord accompanying tone signal. The tone signal is amplified by an amplifier and provided as an output by a loudspeaker.

Growing community of inventors

Kumagaya, Japan

Yoshiro Nakayama