JPS6029957B2 - electronic musical instruments - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for automatically playing a glissando effect using a digital circuit using an up-down counter and an analog circuit.

Conventionally, as a method for automatically playing a glide effect or a glissando effect, the present applicant has previously proposed
624 proposes an automatic glide effect device. These configurations are applied including glissando and portamento effects. FIG. 1 is an explanatory diagram showing the configuration of the above proposed example.

In the figure, a key output signal from a key signal generation circuit 1 consisting of a group of resistors connected in series and a group of short-circuited key switches that are turned on at a tap is held in a voltage hold circuit 2, and passed through the a side of a changeover switch 9. , the musical sound waveform forming circuit 1 is input, and a normal performance is performed. Next, when the selector switch 9 is switched to the b side, the key output signal passes through the switching element 3 and resets the oscillator 4, causing it to oscillate. This results in
The counting operation of the up/down counter 5 is started, and its output is input to the comparator 8 via the ○/A converter 6 and the output of the voltage hold circuit 2 for comparison.The output signal is used to increase the count of the up/down counter 5. /Perform down control. Further, when both inputs of the comparator 8 are input to the matching circuit 7, the switching element 3 is turned off and the oscillator 4 is stopped. Such a branch circuit provides a glissando effect that changes the pitch voltage corresponding to a low frequency to a high frequency with respect to the hold voltage.

Then, the D/A converted output signal of the D/A converter 6 is sent through the musical sound waveform forming circuit, and a performance using the glissando effect is performed.

In this configuration, two systems are used to switch between a normal performance circuit and a performance circuit that provides a glissando effect.
The output voltage from the voltage hold circuit 2 and the output voltage from the D/A converter 6 are slightly different because the pitch voltage output from the key signal generation circuit 1 is due to an error in the resistance value of the series-connected resistor group. This causes a frequency error and the like, which causes the pitch to vary each time the selector switch 9 is operated.

The object of the present invention is to provide an electronic musical instrument that is capable of automatically performing a highly accurate glissando effect with less influence due to resistance value errors in a key signal generation circuit, and has a structure in which a single circuit system can be used for both normal performance and glissando performance. The goal is to provide the following. In order to achieve the above object, the electronic musical instrument of the present invention includes a key signal generating means configured to output a signal corresponding to the pitch of only one key in response to a plurality of keys being pressed, and a key signal generating means configured to output a signal corresponding to the pitch of only one of the keys when a plurality of keys are pressed. key press detection means for detecting that a key has been pressed and outputting a key press detection signal; an up/down counter that counts clock signals input to the clock section and outputs the counted value as an output signal; An oscillator provides a clock signal to the clock section of the up/down counter, and the key press detection signal of the key press detection means causes the oscillator to momentarily change its output clock from a set low oscillation frequency to a high oscillation frequency. means for changing the signal; means for comparing the output signal of the key signal generating means with the output signal of the up/down counter to control the counting direction of the up/down counter; and the output signal of the key signal generating means; means for stopping the up-down counter when the output signal of the up-down counter coincides with the output signal of the up-down counter; and musical waveform forming means for converting the output of the up-down counter into a musical tone of a pitch corresponding thereto; The oscillation frequency of the oscillator is set in advance to a high frequency to enable normal performance, and the oscillation frequency of the oscillator is set to a low frequency in advance to enable glissando performance or portamento performance. It is.

The present invention will be described in detail below with reference to examples.

FIG. 2 is an explanatory diagram showing the configuration of an embodiment of the present invention, and the same components as in FIG. 1 are given the same numbers.

In the same figure, the key switch output 1 of the key signal generating circuit 1 consisting of a series-connected resistor group and a short-circuited key switch group is
One branch is input into a key press detection circuit 12 to detect a high level key press signal 2, and this key press signal 2 is sent to a differential waveform rectifier 13.
is input to the control terminal of the oscillator 4. Then oscillator 4
oscillates, changing from the manually set low frequency to a high frequency for a moment, but then immediately returns to the manually set low frequency, as shown in FIG. This oscillation output 3 is input to the clock (CL) terminal of an up/down counter 5 for counting. D/A converter 6 from up/down counter 5
The key switch output 1 and the output 5 passed through the buffer amplifier 11 are input to a comparator 8 for comparison, and the output signal 6 is used to input an up/down counter 5.
It is connected to the up/down (U/D) terminal of the unit to perform up/down control of the count. Furthermore, both inputs 4 and 5 of these comparators 8 are input to a window comparator 14, which operates so that its output 7 becomes a low level when both inputs substantially match, as will be described later.

The respective inverted signals of this output 7 and the output 2 of the key press detection circuit 12 are sent to an up/down counter 5 via an OR circuit 15.
This is connected to the stop (DIS) terminal of the counter to control the stop of the counting operation.

When either of the two inputs of the OR circuit 15 is at a low level, that is, when the two inputs of the window comparator 14 match,
The up/down counter 5 stops when there is no key press signal 2, and operates in other states. The D/A converted output signal 4 of the D/A converter 6 is sent together with the attack control signal 8 of the up/down counter 5 to a musical tone waveform forming circuit 10' to convert the musical tone waveform. The operation of this configuration will be explained below. Assume now that the key signal generating circuit 1 is pressed and a key press voltage 1 is generated. At this time, the key press generation circuit 12 detects the key press and supplies a low level signal, which is an inversion of the high level signal, to the OR circuit 15, and a low level signal, which is an inversion of the high level signal of the window comparator 14, to the OR circuit 15.
The signal is applied to the R circuit 15 to put the up/down counter 5 into operation. In addition, the high level signal from the key press detection circuit 12 controls the oscillator 4 via the differential waveform rectifier circuit 13 to automatically change the oscillation output 3 from a low frequency to a high frequency for a moment and send it to the up/down counter 5. .

The pitch voltage 5 is also input to one input terminal of a comparator 8, where it is compared with the output voltage 4 of the D/A converter 6. The up/down counter 5 is controlled to perform the following operations. When the tone pitch voltage 5 and the output voltage 4 of the D/A converter 6 almost match, a low level is output from the window comparator 14 and the operation of the up/down counter 5 is stopped. 3a and 3b show a concrete circuit of the window comparator shown in FIG. 2. FIG.

In the same figure a, the input sides of a pair of comparators 14-1 and 14-2 are connected in parallel by crossing the positive and negative sides, and are connected to the respective outputs 11 and 12 via diodes 14-3 and 14-4, respectively. It is extracted as composite output 13.

Figure b shows the input/output characteristics of the outputs 11 and 12 of the comparators 14-1 and 14-2 and the composite output 13.

In other words, the relationship between the input voltage difference and the output voltage is
2 is a symmetrical type in which the sign of the input voltage difference is reversed, and exhibits the characteristic of rapidly increasing near zero. Therefore, the composite output 13 outputs a low level when the difference between the two input voltages is small, that is, when they almost match. FIG. 4 is an explanatory diagram showing the configuration of another embodiment of the present invention, and is an application example when a key data generation circuit is used.

In the figure, a key data generation circuit 21 scans the key switch and outputs a time-division signal 21 of key presses, and 1-scan synchronization (s
One one-scan synchronizing pulse 22 is output from the skin terminal every time one scan is completed.

The counter 22 is reset by this one-scan synchronization pulse 22, and the number of key switches in the key data generating circuit 21 is counted by the clock of the clock generator 23, and the signal corresponds to each key switch. The storage circuit 24 stores the value of the counter 22 in response to the read pulse 21 from the key data generation circuit 21. On the other hand, the output signal 2 of the key press detection circuit 12 that detects the key press signal from the key signal generation circuit 1 described above.
The oscillator 4 is controlled through the differential waveform rectifier circuit 13, and the frequency is automatically changed from a low frequency to a high frequency for a moment. The up/down counter 5 counts this oscillation output 3, and branches the output (■) into two parts, one of which is input to the comparator 25, and the other is sent to the musical sound waveform forming circuit 10' via the D/A converter 6. Convert to The comparator 25 compares the output (■) from the up-down counter 5 with the output (■) of the memory circuit 24, detects A>B, A=8, and A<B, and controls the up-down (U/D) of the up-down counter 5. Output to the terminal. That is, the up/down counter 5 is the comparator 2.
It operates according to a control signal from the oscillator 5, and counts up operations when A<B, stops when A=B, and down operations when A>B using the clock of the oscillator 4. Now, C,
Assume that the tone C is output from the tone waveform forming circuit 10 when the key is pressed.

Next, C. When C2, which has a lower pitch, is pressed, when the key data generation circuit 21 scans the key switch C3, the read pulse 21 is input to the memory circuit 24, and the signal of the counter 22 corresponding to the key switch C2 is inputted. Remember. Since the output signal of the up/down counter 5 at that time is the signal C, the comparator 25 compares the signals C and C2 and controls the up/down counter 5 to perform a down operation. At that time, the up/down counter 5 counts down according to the clock speed of the oscillator 4. The change is outputted to the tone waveform forming circuit 10 via the D/A converter 6. When A=B, the comparator 25 outputs a DIS signal to the up/down counter 5 to stop the counting operation of the up/down counter 25.

The up-down speed can be varied by manually adjusting the frequency of the oscillator 4.

FIG. 5 is an explanatory diagram of the operation of the external part of the embodiment, and illustrates an example of the operation of the oscillator 4 and the change in the output frequency of the musical waveform forming circuit 10. Initially, musical sound waveform forming circuit 1
0 generates the pitch of the previously pressed key. Here, C. When a key is pressed, the output 3 of the oscillator 4 automatically changes from low frequency to high frequency for a moment by the differential waveform rectifier circuit 13, and the up/down counter 5 counts at high speed, so that the pitch changes instantly to C. , becomes. After that, oscillator 4
Output 3 returns to the manually set low frequency. Here, when key C is pressed and C2, which has a lower pitch, is pressed, the up-down counter 5 starts to move down, but since there is no change in the key press signal 2, the oscillator 4 The frequency does not change, and the glissando effect and portamento effect according to the manually set output frequency of this oscillator 4 are obtained. When the C2 pitch is reached, the up/down counter 5 stops its counting operation. One step of the D/A converter 6 provided in each of the above embodiments is a semitone, and a glissando effect can be obtained by raising or lowering each semitone, and the oscillator 4 can be adjusted manually. The speed can be changed by

Also, if one step is less than a semitone, for example 1/4 semitone, it can be used as a portamento effect, so it is also applied to this effect.

For normal performances that do not require glissando or portamento effects, the oscillator 4 can be manually set and maintained at a high frequency in the same circuit, and no separate circuit is required.

In the case of this method, the key signal generation circuit 1 is the musical sound waveform forming circuit 1.
Since it does not generate a signal that directly controls 0 and only outputs a signal for comparison, the resistor group used in the key signal generation circuit 1 should, in principle, have an error within half of the voltage of one step of the D/A converter. It is no longer necessary to use a high-precision resistor in the conventional key signal generation circuit.

As explained above, according to the present invention, an up-down counter and an oscillator that generates the clock applied thereto can be varied from low frequency to high frequency, thereby allowing performance using the glissando effect and normal performance. By using the same circuit, there is no need to provide a voltage hold circuit or a changeover switch, and it is possible to automatically perform a highly accurate glissando effect with less influence due to resistance value errors in the key signal generation circuit.

Furthermore, since there is no need to use high-precision resistors, it is also advantageous in terms of cost.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a proposed substructure example, FIG. 2 is an explanatory diagram showing the configuration of an embodiment of the present invention, and FIGS. 3a and 3b are specific circuit diagrams of main parts of the embodiment of FIG. FIG. 4 is an explanatory diagram showing the configuration of another embodiment of the present invention, and FIG. 5 is an explanatory diagram of the operation of the main part of the embodiment of the present invention. In the figure, 1 is a key signal generation circuit, and 4 is an oscillator. , 5 is an up/down counter, 6 is a D/A converter, 8
10 is a musical waveform forming circuit, 12 is a key press detection circuit, 14 is a window comparator, 21 is a key data generation circuit, 22 is a counter, 23 is a clock generator, 24 is a storage circuit, and 25 is a comparator. Figure 5 Figure 1 Figure 3 Figure N Ship Figure 4

Claims (1)

[Claims] 1. A key signal generating means configured to output a signal corresponding to the pitch of only one of the pressed keys in response to a plurality of pressed keys;
A key press detection means that detects a key press when no key is pressed and outputs a key press detection signal, and an app that counts clock signals input to a clock section and outputs the counted value as an output signal. a down counter, an oscillator that supplies a clock signal to the clock section of the up-down counter, and a high oscillation frequency for an instant from a constant low oscillation frequency set by the oscillator in response to the key press detection signal of the key press detection means. means for controlling the counting direction of the up-down counter by comparing the output signal of the key signal generating means with the output signal of the up-down counter; and the key signal generating means. means for stopping the up-down counter when the output signal of the up-down counter matches the output signal of the up-down counter; and musical waveform forming means for converting the output of the up-down counter into a musical tone of a corresponding pitch. By setting the oscillation frequency of the oscillator to a high frequency in advance, normal performance is possible, and by setting the oscillation frequency of the oscillator to a low frequency in advance, glitsando performance or portamento performance is possible. An electronic musical instrument that is characterized by its ability to break in.