Polyphonic electronic musical instrument

• US 5,054,358 A
• Filed: 03/07/1990
• Issued: 10/08/1991
• Est. Priority Date: 08/17/1987
• Status: Expired due to Term

• Current Assignee: Casio Computer Company Limited
• Original Assignee: Casio Computer Company Limited
• Inventors: Usami, Ryuji
• Primary Examiner(s): Grimley, A. T.
• Assistant Examiner(s): Smith, Matthew S.
• Application Number:
  US07/490,735
• Time in Patent Office: 580 Days
• Field of Search: 84/601, 84/602-607, 84/615, 84/617, 84/626, 84/628, 84/629
• US Class Current: 84/617
• CPC Class Codes: G10H 1/187 using multiplexed channel processors G10H1/186 takes precedence
• CPC Class Codes: G10H 7/00 Instruments in which the tones are synthesised from a data store, e.g. computer organs

Abstract

Memory means is provided such that it is capable of reading and writing tone source control data for an available number of channels. Each channel time is divided into two divisions for instance. In the first half of each channel time, tone source control data for the channel corresponding to the current channel time is read out from the memory means, and in the second half of channel time tone source control data of a given designated channel for setting data is written in the memory means. In this way, tone source control data can be set speedily even if the polyphonic channels are increased in number. Further, with an increased number of polyphonic channels it is possible to synchronize the phase of each tone in a tone mixing mode even when a frequency change is caused by a pitch bender or a vibrato.

Claims

1. A polyphonic electronic musical instrument for generating a plurality of tone signals through a time-division process on a plurality of channels, said instrument comprising:

first memory means for storing a sounding on/off signal for each of the channels;

second memory means for storing frequency data for each of the channels;

third memory means for storing the sounding on/off signal stored in said first memory means;

fourth memory means for storing the frequency data stored in said second memory means;

sounding on/off signal-transferring means for transferring the sounding on/off signal stored in said first memory means to said third memory means;

frequency data-transferring means for transferring the frequency data stored in said second memory means to said fourth memory means;

first means for controlling said sounding on/off signal transferring means such that a sounding off signal is written in an area of said first memory means which corresponds to a plurality of channels assigned to one tone, and the data stored in said first memory means is transferred to said third memory means, after the sounding off signal has been written into said first memory means;

second means for controlling said frequency data-transferring means such that tone frequency data is written in an area of said second memory means which corresponds to a plurality of channels assigned to said one tone, and the frequency data stored in said second memory means is transferred to said fourth memory means, after the tone frequency data has been written into said second memory means, and after the sounding off signal has been transferred to said third memory means by said first means;

third means for controlling said sounding on/off signal-transferring means such that a sounding on signal is written in an area of said first memory means which corresponds to a plurality of channels assigned to said one tone, and the data stored in said first memory means is transferred to said third memory means, after the sounding on signal has been written into said first memory means, and after the data stored in said second memory means has been transferred to said fourth memory means by said second means; and

tone-generating means for starting generating of tone signals phase-synchronized for said channels in response to a sounding on signal and in accordance with the frequency data stored in said fourth memory means, after tone signals are stopped in response to a sounding off signal stored in said third memory means.

2. The polyphonic electronic musical instrument according to claim 1, which further comprises:

operation means for changing the frequency of a tone when operated; and

frequency data-writing means for writing new frequency data in that area of said second memory means which corresponds to all channels assigned to said one tone, when said operation means is operated;

and wherein;

said second means includes means for transferring the new frequency data stored in said second memory means to said fourth memory means; and

said tone generating means generates a tone signal in accordance with the new frequency data transferred to said fourth memory means.

3. The polyphonic electronic musical instrument according to claim 1, wherein said first and third memory means comprise area division of one memory means, and said second and fourth memory means comprise area divisions of another memory means.

4. A sounding source circuit for generating a plurality of tone signals through a time-division process on a plurality of channels, said sound source circuit comprising:

first memory means for storing a sounding on/off signal for each of the channels;

second memory means for storing frequency data for each of the channels;

third memory means for storing the sounding on/off signal stored in said first memory means;

fourth memory means for storing the frequency data stored in said second memory means;

sounding on/off signal-transferring means for transferring the sounding on/off signal stored in said first memory means to said third memory means;

frequency data-transferring means for transferring the frequency data stored in said second memory means to said fourth memory means;

first means for controlling said sounding on/off signal-transferring means such that a sounding off signal is written in an area of said first memory means which corresponds to a plurality of channels assigned to one tone, and the data stored in said first memory means is transferred to said third memory means, after the sounding off signal has been written into said first memory means;

second means for controlling said frequency data-transferring means such that tone frequency data is written in an area of said second memory means which corresponds to a plurality of channels assigned to said one tone, and the frequency data stored in said second memory means is transferred to said fourth memory means, after the tone frequency data has been written into said second memory means, and after the sounding off signal has been transferred to said third memory means by said first means;

third means for controlling said sounding on/off signal-transferring means such that a sounding on signal is written in an area of said first memory means which corresponds to a plurality of channels assigned to said one tone, and the data stored in said first memory means is transferred to said third memory means, after the sounding on signal has been written into said first memory means, and after the data stored in said second memory means has been transferred to said fourth memory means; and

tone-generating means for starting generating of tone signals phase-synchronized for said channels in response to a sounding on signal and in accordance with the frequency data stored in said fourth memory means, after tone signals are stopped in response to a sounding off signal stored in said third memory means.

5. The sound source circuit according to claim 4, further comprising:

frequency data-writing means for writing new frequency data in an area of said second memory means which corresponds to all channels assigned to said one tone, when an instruction for changing the frequency of a current sounding tone is input;

and wherein;

said second means includes means for transferring the new frequency data stored in said second memory means to said fourth memory means; and

said tone generating means generates a tone signal in accordance with the new frequency data transferred to said fourth memory means.