JPS5913656Y2 - Pitch bend device for electronic musical instruments - Google Patents

Description

[Detailed description of the invention] This invention is an electronic musical instrument that has a voltage-controlled oscillator as a sound source oscillator, and controls the pitch bend variable width by providing another variable resistor that variably sets the voltage applied to the variable resistor for pitch bend operation. The present invention relates to an improved pitch bending device that allows for pitch bending.

In general, electronic musical instruments such as music synthesizers produce musical sounds at the pitch corresponding to the pressed key by controlling a voltage-controlled oscillator as a sound source oscillator with a pitch voltage that is set differently for each key. It is designed to combine signals.

Traditionally, this type of electronic musical instrument has been used to adjust the pitch by moving a pitch bend operator (usually a variable resistance slider) from a reference point to the plus side or minus side while holding down the key. A pitch bend device is provided that can change the pitch up and down.

However, in the conventional pitch bend device, since only a pitch bend operator is provided as an operator, the variable width of the pinch bend cannot be controlled from the outside.

That is, the maximum amount of pitch deviation in the vertical direction is fixed, and its value is, for example, ±1200 cents (equivalent to one octave).

Therefore, with this pitch bend device, if you want to shift the pitch by, say, ±500 cents during a performance, you must operate the pitch bend operator to stop it at an appropriate position halfway through its range of motion. Such operations are extremely difficult in practice and impossible to repeat with good reproducibility.

The purpose of this invention is to provide an improved pitch bend device that can appropriately control the variable width of pitch bend (maximum amount of pitch deviation).

A feature of this invention is that a separate variable resistor is provided to variably set the voltage applied to the variable resistor for pitch bend operation, thereby controlling the pitch bend variable width.

According to these features, stable pitch bend variable width control over a wide range can be achieved with a simple circuit configuration.

Hereinafter, preferred embodiments of this invention will be described with reference to the accompanying drawings.

FIG. 1 shows an electronic musical instrument equipped with a pitch bend device according to an embodiment of the invention, and 10 is a voltage-controlled oscillator (VCO) as a sound source oscillator whose oscillation frequency is controlled by a pitch control signal PC. It is.

As will be described later, the pitch control signal PC is generated every time a key is pressed, and has a voltage value corresponding to the pitch name of the pressed key. A sound source signal having a pitch (frequency) corresponding to the pitch name of the key is generated.

This sound source signal is sent to a voltage controlled amplifier (VCA) 14 via a voltage controlled filter (VCF) 12, and the VC
F12 is given timbre characteristics, and VCA 14 is given amplitude envelope characteristics.

The musical tone signal obtained at the output end of the VCA 14 is sent to the output amplifier 1.
6 to a speaker 18, and is converted into a musical tone by the speaker 18.

Here, to explain the system for generating the pitch control signal PC, this system includes a pitch voltage generation circuit 20,
Key-on signal generation circuit 22 and sample hold circuit 24
and a buffer 26.

The pitch voltage generation circuit 20 is for generating a pitch voltage PV corresponding to the pitch name of each key based on a pitch reference voltage RV from a pitch reference voltage generation circuit 40, which will be described later. It includes key switches KS-A and a resistor network RW that supplies voltages of various levels to these key switches.

The key-on signal generation circuit 22 has a group of key switches KS-B that operate in conjunction with a key switch KS-A, and applies a voltage of 10 V to one terminal of these key switches KSB in common. -H are connected in common, and the key-on signal KON is generated from the common connection point.

This key-on signal KON indicates that one of the keys has been turned on.

When a certain key is pressed, the pitch voltage generation circuit 20 generates a pitch voltage PV corresponding to the pitch name of the pressed key, and the key-on signal generation circuit 22 generates a pitch voltage PV corresponding to the pitch name of the pressed key, and the key-on signal generation circuit 22 generates a pitch voltage PV corresponding to the pitch name of the pressed key. A key-on signal KON is generated to indicate that the key has been activated.

The pitch voltage Pv is supplied to the sample hold circuit 24 together with the key-on signal KON.

The sample hold circuit 24 is a sampling game that samples the pitch voltage PV in response to the key-on signal KOH.
G and this game) Capacitor C that holds the output of G
Contains.

By sampling and holding the pitch voltage PV in response to the key-on signal KON and then supplying it to the buffer 26, a pitch control signal PC is obtained at the output side of the buffer 26.

This pitch control signal PC has a voltage value corresponding to the pitch name of the pressed key, and this pitch control signal PC has a voltage value corresponding to the pitch name of the pressed key.
By controlling O, it is possible to obtain a sound source signal with a frequency corresponding to the pitch name of the pressed key.

Note that the pitch control signal PC is also supplied to the VCF 12 via the attenuation variable resistor 28, thereby controlling the cutoff frequency of the VCF 12 according to changes in pitch (normally, as the pitch increases, (The cutoff frequency is also controlled to be high.)

On the other hand, the control voltage generation circuit 30 controls several levels required to form an envelope signal corresponding to the pattern of timbre (filtering characteristics) change and amplitude (amplification gain) change when a key is pressed. Generates voltage CV and controls this control voltage C
V is supplied to each envelope generator (EG) 32,34.

Each envelope generator 32,34 has a key-on signal K.
ON is also supplied.

When the key-on signal KON is generated, the envelope generator 32 generates an envelope signal EVI corresponding to the tone (filtering characteristics) change pattern when the key is pressed, and controls the VCF 12 to change the filtering characteristics. In addition to changing the amplitude over time, the envelope generator 34 generates an envelope signal EV2 corresponding to the amplitude change pattern when a key is pressed, and controls the VCA 14 to change its amplification gain.

As a result of the above configuration, a musical tone signal having a frequency (pitch) corresponding to the note name of the pressed key, predetermined timbre characteristics and amplitude envelope characteristics is obtained on the output side of the VCA 14. The musical tone signal is sent to the speaker 18 via the output amplifier 16, where it is produced as a musical tone.

Now, according to the teaching of this invention, the high-pitched voltage generating circuit 20
By changing the pitch reference voltage RV, which is the source of the pitch voltage PV, in a unique manner, a pitch bend operation is performed in which the pitch is varied over a predetermined width in the vertical direction.

That is, the circuit 4o for generating the pitch reference voltage RV
includes a pitch bend device 50 and a tuning
A circuit 60 is provided.

The pitch bend device 50 is provided with a variable resistor 51 for pitch bend variable width control, a voltage distribution circuit 52, a variable resistor 53 for pitch bend operation, a variable resistor 54 for setting a reference voltage, and an addition circuit 55. There is.

The pitch bend variable width control variable resistor 51 supplies the control voltage Va to the voltage distribution circuit 52, and the voltage distribution circuit 52 supplies one polarity to one end P of the pitch bend operation variable resistor 53 according to the control voltage Va. While supplying the voltage V1, the other end Q of the variable resistor 53 is supplied with a voltage -2 of the opposite polarity corresponding to the control voltage Va.

In the pitch bend operation variable resistor 53, its middle point M is grounded, and the pitch bend voltage Vl) is taken out from the movable element 53a as a pitch bend operator.

The pitch bend voltage vb is supplied to one addition input terminal of the addition circuit 55, and a predetermined reference voltage Vs is applied from the reference voltage setting variable resistor 54 to the other addition input terminal.

With this configuration, the addition output Vr taken out from the output side of the addition circuit 55 can be a voltage output obtained by adding the pitch bend voltage vb to the reference voltage Vs.

Therefore, now, the movable element 53 as a pitch bend operator
If a is operated to reciprocate and dynamically displace a from a position corresponding to the midpoint M toward one end P side and the other end Q side, the added output voltage Vr will be
As a result of adding the positive and negative pitch bend voltages vb corresponding to the displacement of a, the level of the reference voltage Vs changes in the vertical direction by an amount corresponding to the added value.

The variable width of the pitch bend voltage vb in this case is
Since the voltages (1) and -22 supplied to the variable resistor 53 are changed in accordance with the control voltage Va, they can be arbitrarily set variably by the variable resistor 51.

On the other hand, in the tuning circuit 60, the tuning voltage Vt supplied from the variable resistor 61 for tuning operation and the voltage Vr supplied from the adding circuit 55 are added in an adding circuit 62, and the added output voltage of the adding circuit 62 is A tone pitch reference voltage RV consisting of the following is supplied to the tone pitch voltage generation circuit 20.

Therefore, the tone pitch reference voltage RV is obtained by adding or subtracting the tuning voltage Vt from the added output voltage Vr, and the level of this voltage RV is determined by adjusting the variable resistor 6 for tuning purposes.
1, it can be changed as appropriate.

FIG. 2 shows an example of a detailed configuration of the pitch reference voltage generation circuit 40 shown in FIG. 1, and the same parts as in FIG. 1 are given the same reference numerals.

In the pitch bend device 50, a pitch bend variable width control variable resistor 51 has a voltage of +■ applied to one end thereof, and the other end thereof is grounded.

The voltage Va taken out from the movable element 51a of the variable resistor 51 is supplied to the inverting input side of an operational amplifier (hereinafter referred to as an operational amplifier) OP1 connected to operate as a differential amplifier.

A variable resistor V is connected to the inverting input side of this operational amplifier OPI.
A correction voltage is applied from R1 so as to be added to the voltage Va.

Further, a reference voltage Vs is applied from the variable resistor 54 of the adder circuit 55 to the non-inverting input terminal of the operational amplifier OPI.

The output voltage ■1 taken out from the operational amplifier OP1 is supplied on the one hand to one end P of the variable resistor 53 for pitch bend operation, and on the other hand to the inverting input side of the operational amplifier OP2 connected to operate as an inverting amplifier. ing.

A variable resistor V is connected to the inverting input side of this operational amplifier OP2.
A correction voltage from R2 is supplied so as to be added to the output voltage V1.

Input resistance R connected to the inverting input terminal of operational amplifier OP2
7, and a feedback resistor R2 connected between the inverting input terminal and the output terminal.
- As an example, resistors with resistance values of 200 KΩ and 100 KΩ are used, and therefore variable resistors 53
Output voltage of operational amplifier OP2 applied to the other end Q -■
2 is equal to its size ■1/2.

In this way, the voltage distribution circuit 52 including the operational amplifiers OP1 and OP2 supplies the relatively high voltage V1 of one polarity according to the control voltage Va and the relatively low voltage -2 of the opposite polarity to the variable resistor 53, respectively. It is distributed and supplied to one end P and the other end Q.

Note that the reason why a small value is determined as the value of the voltage -2 is to prevent the tone pitch reference voltage RV from becoming less than zero due to this voltage being added to the reference voltage Vs.

(When the pitch reference voltage RV becomes near zero or below,
■C010 stops working).

The pitch bend voltage vb taken out from the movable element 53 a of the variable resistor 53 is supplied to an adder circuit 55 .

The adder circuit 55 includes an operational amplifier OP3 connected to operate as an inverting amplifier, and the operational amplifier OP3
A pitch bend voltage vb and a reference voltage Vs are applied to the inverting input end of the voltage converter in such a manner that they are added to each other.

The reference voltage Vs is taken out from the movable element 54a of the variable resistor 54, to which voltages of +V and -V are respectively applied.

As a result of this configuration, a voltage Vr, which is the inversion of the sum of the pitch bend voltage vb and the reference voltage Vs, is obtained on the output side of the operational amplifier OP3.

The tuning circuit 60 is provided with an operational amplifier OP4 connected to operate as an inverting amplifier, and the inverting input terminal side of the operational amplifier OP4 receives the added output voltage Vr from the adder circuit 55 and the variable resistor VR3.
and the tuning voltage Vt from the movable element 61a of the tuning operation variable resistor 61 are supplied so as to be added to each other.

The output terminal of the operational amplifier OP4 is connected to the base of the emitter follower transistor Tr, and the tone pitch reference voltage RV, which is the inverted voltage output of the sum of the three input voltages mentioned above, is extracted from the load resistor RL of the transistor Tr. It is now possible to do so.

According to the circuit arrangement of FIG. 2, in the same manner as described above with respect to FIG. 1, the pitch bend operation by the variable resistor 53, the pitch bend variable width control operation by the variable resistor 51,
Tuning operations can be performed using the variable resistor 61 and the pitch reference voltage R in response to these various operations.
It is clear that V can be obtained.

Note that the variable resistors VRI, VR2°VH2, 54 are normally arranged within the main body of the musical instrument, and are adjusted as appropriate during manufacture.

Here, a specific example of how much pitch bend (pitch deviation) can be caused when performing a pitch bend operation using the pitch bend device 50 shown in FIG. 2 will be shown.

First, if the pitch deviation PD is expressed in cents, then
It is defined by the following equation.

PD-12001og (1) In the formula (1), fo represents the reference frequency and f represents the actual sounding frequency.

In the electronic musical instrument of the type shown in the example above, since there is a proportional relationship between the pitch voltage and the sound frequency, the maximum upward pitch deviation PDoM and the maximum downward pitch deviation PD
LM is as follows (2).

It is expressed as in equation (3).

Here, Vs is set to 2 [■] by the variable resistor 54, for example.
Since this value is set to (2) above,
By substituting into equation (3), we can obtain the following equations (4) and (5).

PDUM= 1200 log, (1+V1/2)
・・・・・・(4) PDLM= 1200 log2(
1-Vl/4)...(5) These (4)
, According to equation (5), it is clear that the pitch deviation can be controlled according to the voltage , (or the control voltage Va that controls this).

-For example, in order to generate a pitch shift of 600 [sen I-] upward, the value of ■1 is approximately 0.8 from equation (4).
2 (V), and the downward pitch shift at this voltage value is approximately -402 [cents] from equation (5).

Therefore, by adjusting the variable resistor 51 so that ■1=0.82 [■], the movable element 51 as a pitch bend operator
If 3a is moved up and down to the maximum extent to the P side and the Q side, a pitch bend operation with a pitch deviation of 600 [cents] upward and -402 [cents] downward becomes possible.

If it is desired to change the maximum amount of this vertical pitch deviation, that is, the pitch bend variable width, the variable resistor 51 may be adjusted to set a different value as the voltage (1).

The greatest merit of this invention is that various values regarding the maximum amount of vertical pitch deviation can be obtained through such simple operations.

The following table shows various maximum upward pitch deviations PDUM and maximum downward pitch deviation PDL corresponding to each PDUM value.
This is shown in contrast to M, and displaying all or part of these maximum pitch deviations on the operation panel surface of the movable element 51a of the variable resistor 51 provides a guideline for pitch bend variable width control. This is useful for making operations easier.

Note that the units in the following table are cents.

PDUM 1200 1100 1000 900
800 700 (PDLM -1200-101
5-858-722-602-496PDTJM 6
00 500 400 300 200 100 0(
PDLM -402-317-241-172-109
-52,30 As is clear from the detailed description above, the pitch bend device according to this invention does not require any difficult operation such as controlling the amount of mechanical displacement of the pitch bend operator, and can be used for pitch bend variable width control. By adjusting the variable resistor in advance and then simply displacing the pitch bend control element to the maximum extent in the vertical direction, pitch bend control of various variable widths can be achieved with good reproducibility, allowing for a rich variety of performance expressions in electronic musical instruments. It is extremely useful in doing so.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an electronic musical instrument equipped with a pitch bend device according to an embodiment of the invention, and FIG. 2 is a circuit diagram showing details of a pitch reference voltage generating circuit in the electronic musical instrument of FIG. 40... Pitch reference voltage generation circuit, 50... Pitch bend device, 51... Variable resistor for pitch bend variable width control, 52... Voltage distribution circuit, 53... Variable resistor for pitch bend operation, 54... Variable resistor for setting reference voltage, 55... Addition circuit.

Claims (1)

[Scope of utility model registration request] It generates a different pitch voltage for each key, and also controls a voltage-controlled oscillator with the pitch voltage corresponding to the pressed key.
The electronic musical instrument is configured to synthesize a musical tone signal with a pitch corresponding to the pressed key, and includes an adder circuit to which a reference voltage is applied to one adder input terminal, and a pitch bend controller to the other adder input terminal of this adder circuit. a first variable resistor that supplies a pitch bend voltage according to the displacement of the operating movable element; and a second variable resistor that variably sets the voltage applied to the first variable resistor to determine the variable range of the pitch bend voltage. and a resistor,
Depending on the resistance value change of the first and second variable resistors,
A pitch bending device characterized in that a voltage output that is the source of each of the pitch voltages is taken out from an output side of the adding circuit.