Electronic musical instrument of time division multiplexed type

• US 4,287,802 A
• Filed: 05/17/1979
• Issued: 09/08/1981
• Est. Priority Date: 05/19/1978
• Status: Expired due to Term

• Current Assignee: Nippon Yusen Kabushiki Kaisha
• Original Assignee: Nippon Yusen Kabushiki Kaisha
• Inventors: Katada, Naota, Imamura, Akio
• Primary Examiner(s): Witkowski, Stanley J.
• Application Number:
  US06/040,041
• Time in Patent Office: 845 Days
• Field of Search: 84/1.01, 84/1.03, 84/DIG. 2, 84/DIG. 22, 84/DIG. 23, 84/DIG. 20
• US Class Current: 84/617
• CPC Class Codes: G10H 1/188 with means to assign more than one channel to any single key
• CPC Class Codes: G10H 1/22 for suppressing tones; Preference networks
• CPC Class Codes: Y10S 84/02 Preference networks
• CPC Class Codes: Y10S 84/23 Electronic gates for tones

Abstract

An electronic musical instrument having its keyboard divided into plural key ranges with musical tones being generated with tone colors which are different one key range from another. For achieving this object, the instrument comprises channel processors, tone generators, additional tone generators for the lowest (or highest) key in each key range, a common key coder for obtaining key data of depressed keys and a control circuit for supplying key codes delivered out of the key coder to only a channel processor of a corresponding key range. The key coder delivers out key data of depressed keys sequentially one key data at one time slot. According to the invention, the lowest (or highest) tone in a predetermined key range is generated with a tone color corresponding to the key range and also with a different tone color. The time slot allotted to the lowest (or highest) key is divided into two halves and a key code of the lowest (or highest) key is applied to a corresponding channel processor during the first half and is applied to a tone generator for the lowest (or highest) key after being once stored in a register. A lowest key detection circuit generates a pulse defining the second half of the time slot.

Claims

1. An electronic musical instrument comprising:

key switches corresponding to keys;

depressed key detection means for detecting on-off states if said key switches to sequentially deliver key data of depressed keys in respective time slots of a scanning cycle in which keys are scanned in the order of corresponding note pitch;

specific key detection means for detecting the specific time slot in which key data of the note of the first key in a predetermined priority order among the depressed keys is delivered;

a processing circuit for using one half of the specific time slot detected by said specific key detection means as a first processing time and the other half of said specific time slot detected by said specific key detection means as a second processing time, and for applying different processing to the key data of said first key respectively during said first and second processing times;

a first musical tone generation circuit for generating musical tones in response to the key data supplied during said first processing time; and

a second musical tone generation circuit for generating musical tones in response to the key data supplied during said second processing time.

2. An electronic musical instrument as defined in claim 1 wherein said specific key detection means is a circuit which detects the specific time slot to which the first key data in the cycle of sequential key data is delivered by said depressed key detection means.

3. In an electronic muscial instrument having a single keyboard with keys separated into a lower key range and a higher key range in accordance with corresponding note pitch, and having a key coder which scans the keyboard and sequentially provides, during time slots of each scanning cycle, key codes identifying depressed keys, the improvement comprising:

key range detection means for detecting from the key codes provided in each time slot the key range containing the corresponding depressed key, and for gating out the key codes for keys in a certain one of said key ranges during one portion only of each of the corresponding time slots, said one portion being less than the entire time slot,

time shared tone generator means, connected to said key range detection means, for providing musical tones corresponding to each of the key codes gated out in said one portion of said corresponding time slots,

priority key detection means, cooperating with said key range detection means, for determining the one time slot containing the key code for a key of certain predetermined priority amongst the depressed keys in said one key range, and for gating out that key code during the remaining portion of the time slot containing that key code, and

register and monophonic tone generator means, connected to said priority key detection means and responsive only to a key code gated out in said time slot remaining portion, for generating a musical tone corresponding thereto.

4. An electronic musical instrument according to claim 3 further comprising:

a second time shared tone generator having a tone color different from the other time shared tone generator, for providing musical tones correspondong to the key codes provided during time slots which are identified by said key range detection means as being assigned to key codes for keys not in said certain one of said key ranges.

5. An electronic musical instrument comprising:

key switches corresponding to keys arranged in a certain order;

depressed key detection means for detecting on-off states of said key switches to deliver, during sequential time slots of a scanning cycle, key data of depressed keys in the order of arrangement of said keys;

specific key detection means for detecting the one time slot in which key data of the specific key of a predetermined priority among the depressed keys is delivered;

gate means for gating out said delivered key data of depressed keys from said depressed key detection means only during one portion of each of said time slots, said one portion being less than the whole of said time slot, and for gating out, during the remaining portion of only said one time slot detected by said specific key detection means, the key data of said specific key;

a processing unit for processing the key data gated out of said gate means during said one portion of said each time slot to output it as first key data, and processing the key data of the specific key gated out of said gate means during said remaining portion of said only time slot detected by said specific key detection means to output it as second key data;

a first musical tone generation circuit for generating musical tones in response to said first key data; and

a second musical tone generation circuit for generating musical tones in response to said second key data.

6. An electronic musical instrument as defined in claim 5 wherein said specific key detection means is a circuit which detects a time slot to which the first key data in said scanning cycle is delivered.

7. An electronic musical instrument as defined in claim 5 wherein said processing unit processes the key data so that octave data contained in the key data present during said one portion of each time slot is different from octave data contained in the key data present during said remaining portion of each time slot.

8. An electronic musical instrument as defined in claim 5 further comprising an additional musical tone generation circuit, and and wherein said gate means gates out only key data belonging to a predetermined key range and said first musical tone generation circuit generates tones of said predetermined key range, tones not belonging to said predetermined key range being generated by said additional musical tone generation circuit.

9. An electronic musical instrument according to claim 8 wherein said keys are arranged in ascending order of pitch of the corresponding musical notes selected by said keys, said keys being separated into a lower key range and a higher key range, said gate means gating out only key data for depressed keys in said lower key range.