JPS599912B2 - keyboard electronic musical instrument - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a keyboard-type electronic musical instrument in which the envelope or timbre of a musical tone to be produced is temporally controlled according to the position of a key pressed on the keyboard.

Traditionally, music synthesizers are equipped with a voltage-controlled amplifier (VCA) to control volume and a voltage-controlled filter (VCF) to control timbre, and control signals such as envelope signals are added to these to amplify each. The frequency and frequency characteristics are changed.

This control signal is generally a time-varying signal having four time processes: a rise (attack), a fall (decay), a steady state (sustain), and a decay part (release). Furthermore, a control signal having only a rising and attenuating portion may be used. Conventionally, the waveforms of these control signals have remained constant regardless of the range of musical tones.
On the other hand, in natural instruments such as violins and pianos, not only the timbre but also the time processes of rise and decay differ depending on the range. Generally, in low-pitched sounds, the sound rises slowly and falls slowly. At high frequencies, the rise is quick and the fall is also quick. Therefore, conventional music synthesizers were unable to create the sounds of violins and pianos with sufficient accuracy. The present invention is intended to eliminate such drawbacks. Hereinafter, the present invention will be explained based on illustrated embodiments.

FIG. 1 is a block diagram of an embodiment of the invention. In Fig. 1, two adjacent movable contacts of the key switch 2, which are opened and closed by a key (not shown) on the keyboard, are connected by a resistor R, and one of the movable contacts at the end is resistor. It is grounded via R, and the current source 1 is connected to the other end. Therefore, voltages are generated at equal intervals corresponding to the musical scale at the movable contacts of each key switch 2. When a key is pressed, among the pressed keys, the lower one on the drawing)
The voltage on the dynamic contacts appears on the busbar 3. This voltage is A
shall be. Voltage A is applied to sample and hold circuit 4 and voltage comparator 9. The output B of the voltage comparator 9 is `` when the key is pressed.
o'' and puts the sample hold circuit 4 in the sample state, and when the key is not pressed, it becomes b'' and puts the sample hold circuit 4 in the hold state. Therefore, even if the key is released, the voltage C maintains its previous value. This situation can be seen at A in Figure 3.
, B, and C. Voltage C is applied to voltage controlled oscillator (CO) 5 and voltage converter 11 . The voltage controlled oscillator 5 oscillates a scale signal having the frequency of the scale in accordance with the voltage C corresponding to the scale. After this scale signal is frequency-divided and shaped by a frequency divider and waveform shaper (not shown) as necessary, it is added to the voltage-controlled P-wave generator 6 to change it to the desired musical instrument sound, and further voltage-controlled An envelope is applied by an amplifier 7 and the signal is outputted from an output terminal 8. A Slyn signal D is applied to the voltage-controlled wave generator 6 and the voltage-controlled amplifier 7 to temporally control their frequency characteristics and transmission gains.

This control signal D is obtained as follows. The voltage C corresponding to the musical scale is applied to the voltage converter 11 as described above, and the output of the voltage converter 11 is applied to the control signal generator 10 to control the waveform shape of the control signal D. The output B of the voltage comparator 9 is also applied to a control signal generator 10 to control the generation of a control signal D. Regarding this point, the second
Description will be made with reference to a specific example of the control signal generator 10 shown in the figure. In FIG. 2, a transistor 21, resistors 19, 2
2 is an inverter, which operates as a switch to charge the capacitor 33.

Resistors 23, 25, 26 and transistor 24 constitute an inverter. Transistor 27 constitutes a switch that discharges capacitor 33. Charging is done using a protective resistor 23
, a variable resistor 30, and a diode 32.
The diode 32 is for backflow prevention. Discharging is performed by a series circuit of a protective resistor 29 and a variable resistor 31. The resistor 35 and the transistor 34 constitute a buffer, and output the voltage of the capacitor 33 to the output terminal 36. Output B is applied to input terminal 20 . This output B is "1"
(The voltage is +00), the transistor 21 is off and the transistors 24 and 27 are on, so the charge in the capacitor 33 is discharged and the voltage D is almost 0.
(V). When the output B becomes 00ゝ (voltage is assumed to be 0(7)), the transistor 21 is turned on and the transistor 2 is turned on.
4 and 27 are turned off, and capacitor 33 is +Vcc (7
) is charged. The charging speed 4 is determined by the resistor 28, variable resistor 30 and capacitor 33. Output B again''
1'', the transistor 27 is turned on again, and the capacitor 33 is discharged to 0CV).The speed of this discharge is determined by the resistance values of the resistor 29, the variable resistor 31, and the capacitance of the capacitor 33.Now, the variable resistors 30 and 31 The resistance value of is made variable by voltage C. To this end, a combination of a CdS photocell and a lamp is used for variable resistors 30 and 31, and voltage C is applied to the lamp to adjust the light intensity of the ship. The resistance value of the CdS photocell is controlled electrically.The voltage converter 11 may be simply a buffer to drive the lamp.The voltage C is controlled by the key, that is, by the scale. The voltages are different.

Therefore, the values of the variable resistors 30 and 31 also take different values depending on the musical scale. Since the values of resistors 28 and 29 are usually small, the charging and discharging time constants will vary depending on the values of variable resistors 30 and 31. As a result, as shown in FIG. 3D, control signals having different rising and attenuating parts for scales G, E, and C can be obtained. If the voltage control amplifier 7 is controlled using this control signal D,
A low note C has a slow rise and decay, while a high note G has a fast rise and decay. These sounds are very similar to the sounds of nature. Furthermore, by controlling the voltage-controlled filter 6 using this control signal D, it is possible to control the timbre according to the musical range. Incidentally, in natural musical instruments, the rising and falling speeds are slightly different for each range, and the relationship between the range and the falling speed is generally non-linear.

Therefore, by making the input/output characteristics of the voltage converter 11 nonlinear in accordance with such a relationship, and controlling the waveform of the control signal D according to the nonlinear characteristics, it is possible to create musical sounds that more closely resemble natural musical instruments. I can do it. For this purpose, a polygonal approximation circuit combining a diode and an operational amplifier may be used, or a nonlinear element such as a varistor may be used. Further, although the circuit having attack and release has been described above with reference to FIG. 2, it is also possible to use a circuit that generates control signals having other time steps.

In these circuits, the constant of the circuit that determines the time constant may be configured to vary according to the musical scale. Also,
Separate control signal generators may be provided for the voltage controlled filter 6 and the voltage controlled amplifier 7, respectively.

As explained above, the present invention is capable of varying the waveform changes such as the rise, fall, and decay of a control signal for temporally controlling the envelope and timbre of musical tones depending on the pressed position of the keyboard. At the same time, the signal representing the key press position on the keyboard is non-linearly converted and supplied to a control signal generator, which generates a control signal that produces the optimal envelope or timbre change for each range. , the excellent effect of being able to freely create natural-looking musical tones that match natural phenomena over a wide range of sounds can be obtained.

[Brief Description of the Drawings] Fig. 1 is a block diagram of main parts of an embodiment of the present invention, Fig. 2 is a circuit diagram of an example of a control signal generator used in the present invention, and Fig. 3 is a block diagram of the main parts of an embodiment of the present invention. FIG. 2...keyboard, 4...sample hold circuit, 5...voltage controlled oscillator, 6...
Voltage controlled filter, 7... Voltage controlled amplifier, 9.
...Voltage comparator, 10...! Leg signal generator, 11... Voltage converter.

Claims (1)

[Claims] 1 comprising a keyboard and a control signal generator that generates a control signal for temporally controlling the envelope of a musical tone or the timbre of a musical tone based on a signal representing the position of a pressed key on the keyboard; By varying the time constant of the waveform of the control signal output from the control signal generator according to the position, the control of the musical tone is made different depending on the range, and the key depression position of the keyboard is A signal representing the above is converted non-linearly according to the upper and lower pitches of the keyboard range and is supplied to the control signal generator, so that the optimum envelope change or timbre change time constant can be obtained for each range. A keyboard-type electronic musical instrument.