Electronic musical instrument

A polyphonic keyboard electronic musical instrument having a specified number of tone production channels, comprising:

• key information generating means for generating key information relating to depressed ones among keys in a keyboard,
• channel assignment means for assigning said key informations to available ones of the specified number of tone production channels,
• multiplexing means for time division multiplexing said assigned key informations by delivering each key information in parallel data format, said key informations being delivered sequentially in time division multiplexed order;
• tone generating means having the same number of tone generators as said specified number of tone production channels, each of said tone generators corresponding to a respective one of said tone production channels, and
• demultiplexing means connected between said multiplexing means and said tone generating means for demultiplexing said delivered key informations and for supplying each demultiplexed key information to the tone generator corresponding to the tone production channel to which said delivered key information is assigned, so that said tone generators respectively generate tone signals in accordance with the respective supplied key information.

A polyphonic electronic musical instrument comprising:

• keyboard means having a plurality of keys,
• key information generating means for generating key information relating to depressed ones among said keys,
• channel assignment means for assigning said key information to available ones of a specified number of tone production channels,
• envelope information generating means for generating envelope information serving to determine an envelope characteristic of a tone, said envelope information being used commonly throughout all of said tone production channels,
• multiplexing means connected to said channel assignment means and said envelope information generating means for transmitting said key information and said envelope information over output lines using a predetermined number of time slots, each of said key information being allotted to a predetermined time slot in accordance with the assigned tone production channel of the key information and the envelope information being allotted to a predetermined time slot on one or more of said output lines in which said key information is not provided,
• tone generating means having tone generators each of which corresponds to a respective one of the tone production channels,
• envelope imparting means having envelope imparting circuits each of which is connected to a respective one of said tone generators;
• and
• demultiplexing means connected to said output lines for supplying said transmitted key information to the tone generators corresponding to said tone production channels to which said transmitted key information is assigned respectively and for supplying said transmitted envelope information to all of said envelope imparting circuits, said tone generators generating tone signals in accordance with said supplied key information respectively and said envelope imparting circuits imparting the envelope characteristic to the corresponding tone signals.

In a keyboard polyphonic electronic musical instrument of the type having plural tone generator channels, the number of such channels being considerably fewer than the total number of keys, the improvement comprising:

• memory means storing a channel assignment table containing for each assigned channel a key code and associated key depression state data for the selected key which is assigned to that channel,
• data transmission lines,
• time division multiplex means for repetitively, consecutively transmitting the contained key codes and associated key depression state data via said data transmission lines during corresponding intervals in each time division multiplex cycle, and
• demultiplexer means, connected to said data transmission lines and receiving said time division multiplex key codes and data, for demultiplexing the same and supplying to each tone generator channel only the demultiplexed key code and associated key depression state data for the selected key assigned to that channel.

A keyboard electronic musical instrument having a specified number of tone production channels connected by a number of output lines, comprising:

• a tone production assignment circuit for assigning production of a tone selected by depression of a key to one of said channels and generating key information representing the note name of the assigned tone and key-on information representing depression or release of the key with respect to each channel to which tone production has been assigned, said key information and said key-on information for each channel together having a certain total number of bits;
• a number of parallel output transmission lines;
• data multiplexing means for time division multiplexing said key information and key-on information by delivering the same on said output transmission lines in parallel data format, said information being delivered sequentially in time division multiplexed order,
• a tone generator for generating the tone assigned to each channel in accordance with the multiplexed information, and
• means for inserting envelope control information used commonly throughout all of the channels or used for only a specified channel in any one or more of the output transmission lines at a suitable timing when component data of the key information or the key-on information is not provided on said one or more of the output transmission lines.

In a keyboard electronic musical instrument of the type having a small number of tone generator channels, for which channels key code and key depression state data are supplied in time division multiplex format, the improvement comprising:

• assignment memory means containing a channel assignment table in which there is a data entry position for each tone generator channel,
• first means for ascertaining by comparison with prior entered data in said table whether a key code for a selected key is already entered in said table and if not, for entering the key code and associated key depression state data for that selected key into an available data entry position of said table,
• second means for reading out all of the entered key codes and associated key depression state data from said channel assignment table in a certain order and in certain delivery time zones for time division multiplex transmission to said tone generator channels, and
• timing control means, cooperatively connected to said first and second means, for establishing a timing and order for key code and data entry into said table by said first means, and for establishing a different timing and order for readout and transmission of key codes and data from said table by said second means.