JPH0137752B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic musical instrument having a plurality of key switches and switches for controlling various musical tones or functions, and particularly relates to a method for connecting a plurality of key switches and a plurality of control switches to a predetermined utilization device. Regarding simplifications.

In general, in keyboard-type electronic musical instruments such as electronic organs and electronic pianos, an important problem lies in the interconnection between the keyboard switch and the sound source circuit. A typical electronic organ has several manual keyboards, a pedal keyboard, and a bank of stop selection switches. If you connect each keyboard and stop switch to the circuit using separate connection wires, the wiring will become very complicated.
Therefore, assembly costs are high and repair and inspection are difficult. For this reason, it has been desired to simplify the wiring connections.

Incidentally, electric musical instruments such as electronic organs include circuitry that transfers tone selection information from a keyboard switch to appropriate circuitry by using time division multiplexing techniques. The above circuit example is US Patent No.
No. 3610799. The above U.S. patent no.
As stated in the preface of issue 3610799,
An important advantage of multiplexing is that it significantly reduces the amount of electrical wiring required to transfer information from the keyboard to the tone selection section of the organ.

Furthermore, the multiplexing device can be used to transfer information other than tone selection information. For example, a separate multiplexing device for transferring information from a tab switch to a control pointing circuit is provided in U.S. Pat.
column. The multiplexing device reduces the amount of wiring that would be required if the device was not utilized. However, this reduction is expensive and complex since the tone selection device is achieved by a separate and additional multiplexing device.

An object of the present invention is to provide an electronic musical instrument that reduces the number of wires connecting a plurality of key switches and switches for controlling various musical tones or functions and devices that utilize the same, thereby simplifying the circuit and reducing costs. The present invention provides an electronic device that has a plurality of key switches and a plurality of musical tone/function control switches, and generates a musical tone in response to the operation of the plurality of key switches and the plurality of musical tone/function control switches. In a musical instrument, a multiplexing means for multiplexing together the outputs of a plurality of key switches and the outputs of a plurality of tone/function control switches is inputted, and a signal multiplexed by the multiplexing means is inputted, and a signal multiplexed by the multiplexing means is input. The above object is achieved by including distribution means for distributing information regarding the included key switches and information regarding the control switches to predetermined circuits, respectively.

The invention will now be described in detail with reference to the embodiments of the accompanying drawings.

In the key encoding device 10 of FIG. 1, the key switches to be encoded are arranged in a switch matrix circuit 11 consisting of M groups each containing N switches. These switches are associated with N rows of output lines 12 and are selected by group selection counter 13 to select one of M groups.
When one is energized, only the line corresponding to the closed (on) switch in the energized group is provided with an output (ie, a switch-on signal).

Output lines 12 from switch matrix circuit 11 are sequentially scanned by line scan logic 14 in cooperation with N line select gate circuit 15. Each line 12 is then connected to a code matrix circuit 17 via a bus 16. If the line 12 conductive to the code matrix circuit 17 is associated with a closing switch of the energizing group in the switch matrix circuit 11, a switch-on signal is being applied, and in response to this switch-on signal, conduction in the line 12 is established. A column identification code signal (hereinafter simply referred to as a code) that designates a line appears on the bus bar 18. This code is the bus 19 from the group selection counter 13 representing the energized group.
(i.e., the selection signal), the closed switch in the matrix circuit 11 is clearly identified. This encoded key data is supplied to appropriate utilization means 20-22.

If the line conducted to code matrix circuit 17 is associated with an open (off) switch, code matrix circuit 17 will not provide a code output to bus 18. When there is no code output, the line scanning logic 14 and gate circuit 15 immediately connect the next line among the N output lines 12 to the code matrix circuit 17. Until the state in which no code is output ends, the no-code detection circuit 23 determines that no code signal is present on the bus 18, and based on this, it outputs a signal via the OR circuit 24 in order to satisfy the condition of the AND circuit 25. supply The one clock pulse supplied from the clock generator 26 via the AND circuit 25 where the condition is met advances the N-ary circular shift register 27 by one step. This causes the line selection gate circuit 15 to conduct the next subsequent matrix output line 12 to the code matrix circuit 17. Scanning of keyswitches that are not selected proceeds at high speed.

N-ary shift register 27 is a single binary bit 1
Contains. When each subsequent stage receives this binary signal 1, the corresponding line selection gate circuit 15 is operated in sequence. When the shift register 27 recirculates, a pulse is applied via line 28 to the counting input of the group selection counter 13. This increments the contents of counter 13, thus allowing the next switch group in matrix circuit 11 to be selected. The scanning is interrupted such that the N output lines 12 corresponding to each switch of the newly selected group are made conductive to the code matrix circuit 17 one by one. The group selection counter 13 is M-ary, so the matrix circuit 1
One complete switch group is repeatedly selected in sequence.

A coded output is produced on bus 18 each time line 12 associated with a close (on) switch is conducted to code matrix circuit 17. As a result, no output is generated from the no-code detection circuit 23,
The shift register 27 is maintained as it is. This interrupts the scanning and makes the coded signals available to said means 20-22. Scanning is interrupted when a response or "OK" signal is provided to OR circuit 24 via line 30. Receipt of this "OK" signal provides a clock pulse to shift register 27, which causes the next matrix output line 12 to be scanned. The response or "OK" signal may be supplied from the delay circuit 31 a predetermined time after the generation of the code output of the bus 18. In another embodiment, the response signal may be generated by the use actions 21 and 22 after the encoded key information is used.

A specific example of the key encoding device 10 is shown in FIG. 2A.
It is shown in FIG. 2B. In the figure, the switch matrix circuit 11 includes a plurality of switches 35-1, 35-2, . ing. Each switching position of switch 35-j is considered a separate switch in matrix circuit 11. A diode 36 is associated with each switch 35.
For example, the switch 35 used for sound selection is
Operated by keyboard or pedal keys. Other switches 35 are used for stop selection for attack and decay control, or for other functions in the electronic musical instrument.

In the specific example of FIG. 2A, the M-stage circular shift register 13' is a counter 13 that sequentially selects M switch groups in the matrix circuit 11.
used instead of. Each output stage 13- of the register
1, 13-2, 13-M is group selection line 1
9-1, 19-2, . . . 19-M, respectively. Only one stage of the register 13' has a binary signal 1, and the corresponding switch group 3
5 is selected. All remaining stages of register 13' are binary signal 0's. Each time a pulse is received on line 28, the register 13' is shifted, passing the only signal 1 bit to the next stage. This selects the next switch group in the matrix circuit 11.

For example, if stage 13-M of the register is a single signal 1
, the line 19-M selecting the associated group will be at a positive voltage, which causes the switch 35-M connected to line 19-M to
Groups 1 to 35-N are selected. All other group selection lines 1 except line 19-M
9 is the ground voltage. When the next shift pulse occurs on line 28, register 13' recirculates, transferring the signal 1 bit to stage 13-1 and selecting the switch group associated with line 19-1.

The output line 12 of the matrix circuit is connected to the resistor 37-
1 to 37-N, typically biased to ground voltage. However, if there is a closed switch in the selected group, the corresponding output line 12 will be high. In other words, it becomes the positive voltage level supplied from the selection stage of the register 13', and this becomes the switch-on signal. Thus, as shown in FIG. 2A, when switch 35-2 is closed and line 19-M is selected, output line 12-2 will be high and all other output lines 12 will be low. . Of course, one or more switches in each selection group may be closed, or none of the switches may be closed.

The line selection gate circuit 15 has one input side connected to each matrix output line 12-1 to 12-.
NAND gates 15-1 to 15- to which N is connected
It has N. The other input side of the NAND gate 15 is N
Leading circular shift registers 27-1 to 27-N are connected, respectively. This register also has AND circuit 2
contains a single binary signal 1 shifted by the occurrence of pulses from 5 to 5. The stage of the register 27 containing this signal 1 satisfies the condition of the corresponding NAND gate 15, and the conditions of the other NAND gates 15 do not hold.

According to this arrangement, each matrix output line 12 is connected sequentially to the code matrix circuit 17 as the bits of a single binary signal 1 are circulated through the shift register 27. For example, at the beginning of a line scan cycle, register stage 27-1 opens line select gate circuit 15-1 to
-1 to connect the output line 12-1. By successive shifts of register 27, gate 15-2
15-N to 15-N are sequentially opened, and the corresponding output lines 12-2 to 12-N are sequentially connected to the code matrix circuit 17. Bit of signal 1 is in stage 27
-1, the same pulse supplied via line 28 is applied to group select register 1.
3', thereby matrix circuit 1
Select the next switch group after 1.

Code matrix circuit 17 includes a diode 38 interconnecting input line 16 and output line 18.
-1 to 38-l. Output line 18 is biased to a positive voltage +V through a group of resistors 39.
If the output line 12 conducted to the code matrix circuit 17 is associated with a selected and closed switch in the matrix circuit 11, then
The matrix circuit 17 provides code outputs on output lines 18-1 through 18-Q. If the selected line 12 is associated with an open switch in the matrix circuit, line 18
-1 through 18-Q all remain high, representing the absence of code output.

If group line 19-M is selected, when line 12-1 is conducted to code matrix circuit 17, input line 16-1 remains high since the corresponding switch 35-1 is open. It is. In this case, all of the output lines 18 remain high and no code output is generated. When gate 15-2 opens, line 16
-2 is a low level because the corresponding switch 35-2 is closed. Therefore, output line 18-2, which is connected to line 16-2 through diode 38-5, goes low and lines 18-1 and 18-Q remain high;
This combination forms the code specifying the selected line 16-2. Along with the group identification signal on line 19-M, the code on line 18 significantly identifies that switch 35-2 is closed.

In the embodiment of FIG. 2A, the no-code detection circuit 23 is an AND circuit 23' to which line 18 is connected.
Consisting of If lines 18-1 through 18-Q are all high, indicating a no code condition, the output of AND circuit 23' is also high. This output passes through the OR circuit 24, satisfies the condition of the AND circuit 25, and supplies the shift register 27 with a clock pulse. This shifts the shift register 27 and makes the next line 12 conductive to the code matrix circuit 17. Assuming no code is generated again on line 18,
The next clock pulse is applied to register 27. In this way, the closed switch 3
Scanning continues at the clock rate of clock pulse generator 26 until 5 is detected. When detected, a code output appears on line 18 and at least one of lines 18-1 through 18-Q goes low. As a result, the output of the AND circuit 23' becomes low level. A response or "OK" signal is sent from the utilization devices 21, 22 or delay circuit 31 to line 3.
Scanning is halted until sent through 0.

In the illustrated example, lines 19-1 and 19
The switch group of matrix circuits 11 selected by -2 is associated with the first device 20 used, and the switches selected by lines 19-3 to 19-5 are used with the second device 21. and the switches selected by lines 19-6 to 19-M are used for controlling the third utilization device 22. FIG. 2B shows an example of the arrangement of gate circuits for supplying encoded signals from the key encoding device 10 to each of the utilization devices 20-22.

Group selection lines 19-1 and 19-2 are connected to OR circuits 40, respectively, and matrix circuit 11
generates a gating signal on line 41 when either of the first two groups is being scanned. This gate signal is applied to the AND circuit group 4.
2 and open the code feed lines 18-1 to 18-1.
8-Q and group designation lines 19-1, 19-
2 is connected to the first usage device 20. Similarly,
When any of the group selection lines 19-8 to 19-5 is selected, this line 19-8 to 19-5 is selected.
The output AND circuit group 43 is opened by a signal supplied on the line 44 via the OR circuit 45 to which 9-5 is connected. This AND circuit group 43 receives the code signal of line 18 and the lines 19-3 to 19-19.
-5 group designation signal is supplied to the second utilization device. Line 4 supplied via OR circuit 48
The AND circuit group 46 opened by the signal No. 7 is
When any of the group selection lines 19-6 to 19-M is selected, an encoded output is supplied to the third utilization device 22.

When the encoded output is provided to the first utilization device 20, a reply or "OK" signal is sent by the delay circuit 31. During this time, ie, when either group select line 19-1 or 19-2 is selected, the resulting signal on line 41 also causes AND circuit 50 to open. When a code output is generated on line 18, an output is generated from NAND circuit 51. This output is supplied to the delay circuit 31 via the AND circuit 50. At the end of the delay time, the circuit 31 is “OK”
A signal is sent out on line 30.

The key-encoding device 10 of the present invention may be used with any type of utilization device, but in particular with a keyboard of the type described by Deutsch in JP-A-48-90217 ``Electronic Musical Instruments''. Useful with electronic musical instruments. In this electronic musical instrument, the fundamental frequency of each musical tone generated is determined by a frequency number selected from a frequency number storage device. The timbre of a musical tone is determined by a combination of pre-stored harmonic coefficients, each coefficient determining the amplitude associated with the Fourier components making up the generated musical waveform. Several combinations of such harmonic components are individually stored,
It may also be made available for use by selection with a stop selection switch. Attack and decay are performed digitally by systematically varying the amplitude values of the Fourier components that are constructed in successive sound generation cycles.

When the key coding device 10 is used in such a computer towel gun, the first utilization device 2
0 may be provided with attack and decay control elements, the second utilization device 21 may be provided with a stop selection circuit, and the eighth utilization device 22 may be comprised of a sound generation circuit. In such a configuration, line 19-6
The switch groups selected by 19-M are manual keyboard and pedal keyboard switches for tone selection. The encoded signal supplied to the sound generation circuit 22 via the gate circuit 46 is used to recall the corresponding frequency number from memory.
During this time, the coded signal supplied via the gate circuit 46 directly becomes the frequency number memory address of the selected tone. Similarly, attack, decay control switches and stop selection switches are included in matrix circuit 11, and line 1
9-1, 19-2 and 19-8 to 19-5 individually.

As described above, according to the present invention, the wiring between a plurality of key switches and various control switches and devices using the same can be significantly reduced, and the circuit can be simplified and costs can be reduced.

[Brief explanation of drawings]

FIG. 1 is an electrical block diagram showing one embodiment of a key switch scanning and encoding device according to the present invention, and FIGS. 2A and 2B are schematic electrical circuit diagrams showing specific examples of the circuits of each part in FIG. 1. 10...Key coding device, 11...Switch matrix circuit, 13...Group selection counter, 14...Line scanning logic, 15...Line selection gate circuit, 17...Code matrix circuit, 20-22...Utilization Device, 27...N-ary shift register.

Claims (1)

[Scope of Claims] 1. An electronic musical instrument that has a plurality of key switches and a plurality of musical tone/function control switches, and generates musical tones in response to the operations of the plurality of key switches and the plurality of musical tone/function control switches. a multiplexing means for multiplexing together the outputs of the plurality of key switches and the outputs of the plurality of tone/function control switches; inputting the signal multiplexed by the multiplexing means; and distribution means for distributing information regarding the key switch and information regarding the control switch contained in the electronic musical instrument to respective predetermined circuits.