Polyphonic electronic musical instrument

• US 5,007,323 A
• Filed: 08/01/1988
• Issued: 04/16/1991
• Est. Priority Date: 08/07/1987
• 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:
  US07/226,936
• Time in Patent Office: 988 Days
• Field of Search: 84/1.28, 84/1.25, 84/DIG. 2, 84/1.01, 84/1.03, 84/601, 84/602, 84/603-607, 84/615, 84/617, 84/626, 84/628, 84/629
• US Class Current: 84/607
• 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 simultaneously generating a plurality of tone signals through a time-division process on a plurality of channels, comprising;

first memory means for storing tone waveform data;

second memory means for storing waveform control data including access data for accessing said first memory means for each channel;

allotting means for successively allotting on a time-division basis a channel time for each of a plurality of channels as a process time of that channel;

dividing means for dividing each channel time alloting by said allotting means into a plurality of divisions; and

read/write control means for functioning in at least one division of time provided by said dividing means for accessing said first memory means by reading out the waveform control data corresponding to the current channel time from said second memory means, and also for functioning in at least one of the remaining divisions of time for writing the waveform control data of a given channel designated at that time to be changed in an area of said second memory means corresponding to said given channel.

2. The polyphonic electronic musical instrument according to claim 1, wherein each channel time is divided into two halves.

3. A sound source circuit for permitting simultaneous generation of a plurality of tone signals through a time-division process on a plurality of channels, comprising:

first memory means for storing waveform data;

second memory means for storing waveform control data including access data for accessing said first memory means for each channel;

allotting means for successively allotting on a time-division basis a channel time for each of a plurality of channels as a process time of that channel;

dividing means for dividing each channel time allotted by said allotting means into a plurality of divisions; and

read/write control means for functioning in at least one division of time provided by said dividing means for accessing said first memory means by reading out the waveform control data corresponding to the current channel time from said second memory means, and also for functioning in at least one of the remaining divisions of time for writing the waveform control data of a given channel designated at that time to be changed in an area of said second memory means corresponding to said given channel.

4. A polyphonic electronic musical instrument for generating a plurality of tone signals through a time-division process on a plurality of channels;

comprising;

operation means for varying a frequency of a musical tone through an operation of said operation means;

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

second memory means for reading, writing and 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;

varying means for varying the frequency data stored in said second memory means corresponding to a channel which is allotted with a currently generated musical tone;

transfer means for transferring the sounding on/off signals in each of said channels stored in said first memory means to said third memory means, and for transferring the frequency data stored for each channel in said second memory means to said fourth memory means, when variation of the frequency data being varied is completed by said varying means and one cycle of all channels is completed;

tone generation means for generating musical tones according to the sounding on/off signal and the frequency data for each channel transferred to said third and fourth memory means, respectively;

means for functioning in a first half of each channel time for reading out from said first and second memory means the stored sounding on/off signal and frequency data for each channel, and for also functioning in a second half of each channel time for writing the sounding on/off signal and frequency data read out for each channel from said first and second memory means to said third and fourth memory means, respectively; and

means for functioning in the first half of each channel time for reading out from said third and fourth memory means the stored sounding on/off signal and frequency data for each channel and for providing the read-out data to said tone generating means, and for also functioning in the second half of each channel time for writing sounding on/off and frequency data for each channel in said first and second memory means, respectively.

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

allotting means for successively allotting on a time-division basis a channel time for each of a plurality of channels as a process time of that channel;

dividing means for dividing each channel time allotted by said allotting means into a plurality of divisions;

a source of control data corresponding at least to current channel time; and

control means for functioning in at least one division of time provided by said dividing means for operating on control data corresponding to current channel time, and for functioning in at least one of the remaining divisions of time for changing control data of a given channel designated at that time.

6. A sound source circuit for permitting simultaneous generation of a plurality of tone signals through a time division process on a plurality of channels, comprising:

allotting means for successively allotting on a time-division basis a channel time for each of a plurality of channels as a process time of that channel;

dividing means for dividing each channel time allotted by said allotting means into a plurality of divisions;

a source of control data corresponding at least to current channel time; and

control means for functioning in at least one division of time provided by said dividing means for operating on control data corresponding to current channel time, and for functioning in at least one of the remaining divisions of time for changing control data of a given channel designated at that time.