JPH0651779A - Electronic musical instrument - Google Patents

Abstract

PURPOSE:To modulate the frequency, amplitude, etc., of a musical sound, generated when a waveform is repeatedly read out, without any feeling of monotonousness by imposing a modulation effect on a musical sound signal when a repetitive read period is entered. CONSTITUTION:When a read of a waveform memory reaches the tail of waveform data, a comparator 36 outputs an arrival signal, the read address AD is reset to 'repetitive start address LT + over value', and a counter 39 counts up. Those operations are repeated each time the read of the waveform memory reaches the tail of the waveform data. Then various modulation signals (TD, AD, ED, and FD) corresponding to the counted value of the counter 39 are outputted from a modulation information memory 40 to impose modulation on the frequency, higher harmonic component ratio, amplitude, sound image, reverberation, etc., of the musical sound signal. Consequently, a generated musical sound is given a delicate variation and then no monotonousness is felt.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to electronic musical instruments, and in particular,
The present invention relates to an electronic musical instrument having a waveform memory, which sequentially reads musical tone waveforms from the waveform memory and, when reaching the end of a waveform, repeatedly produces a predetermined section to generate a musical tone.

[0002]

2. Description of the Related Art A conventional electronic musical instrument, such as an electronic piano, records a sound of an actual musical instrument such as a piano by PCM, processes the data and stores the processed data in a waveform memory, and corresponds to the pitch of a depressed key. A waveform is read from the waveform memory at an address interval to generate a musical sound.

The actual sound of a piano is several tens of seconds when it is long, and a huge amount of memory is required to store it until the end of the waveform. That is, since the change in the waveform is relatively small, the musical tone waveform is generated by repeatedly reading a predetermined section of the waveform memory.

[0004]

In the conventional electronic musical instrument as described above, the same waveform is repeated many times to generate a musical tone signal when a certain section of the waveform memory is read out repeatedly. However, there is a problem that the generated musical sound becomes monotonous due to the periodicity.

An object of the present invention is to improve the above-mentioned problems of the prior art and to modulate the frequency, amplitude, etc. of a musical tone generated when a waveform is repeatedly read out without feeling monotonous.

[0006]

According to the present invention, there is provided an electronic musical instrument having a waveform memory, wherein musical tone waveforms are sequentially read from the waveform memory, and when the end of the waveform is reached, a musical tone is generated by repeatedly reading a predetermined section. In the above, there is provided a detecting means for detecting that the repetitive reading period has started, and a means for applying a modulation effect to the tone signal in accordance with the output of the detecting means.

[0007]

By such means, the generated musical tone is subtly changed, so that the musical tone becomes closer to the actual musical tone of the musical instrument, and monotonousness is not felt.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram showing a hardware configuration of an electronic musical instrument to which the present invention is applied. In FIG. 1, a CPU 1 controls the entire electronic musical instrument such as key assignment and sound generation control. The ROM 2 stores programs and data necessary for key assignment, sound generation control, and the like.
The RAM 3 stores key assignment data, sound source control data, and the like. It should be noted that a part or all of the RAM 3 is backed up by a battery, and the data and the like set by the tone color setting switch are retained even when the power is turned off.

The keyboard section 4 comprises a plurality of keyboards provided with switches and a circuit for sequentially reading the switch contacts of the keyboard under the control of the CPU 1. The operation panel unit 5 is
It is composed of a switch group such as a tone color setting switch, a circuit for sequentially reading each switch contact of the switch group under the control of the CPU 1, and a display device by an LCD or LED.

As will be described later, the musical tone generating section 6 is configured to read a waveform signal from a waveform memory at an address interval corresponding to a designated frequency and output a digital musical tone waveform under the control of the CPU 1. Further, the musical tone generating section 6 is generally configured to be capable of simultaneously producing a plurality of channels such as 32 channels by time division multiplexing processing.

The D / A converter 7 D / A converts the digital musical tone signal output from the musical tone generating section 6. The analog signal processing section 8 is a circuit for performing simple filter processing and amplification processing for noise removal on the analog tone signal.
Reference numeral 9 is an amplifier, and 10 is a speaker. The D / A converter 7, the analog signal processing unit 8, the amplifier 9, the speaker 10
There are two for each of the left and right. A bus 11 connects each circuit.

FIG. 2 is a block diagram showing the internal structure of the musical tone generating section 6. The parameter memory 20 is a musical sound generation unit 6
Is a memory for storing tone color information for each channel.
The stored contents include read address information (FI) such as read start address, read end address, and repeat start address of the waveform memory, envelope information (AI) such as level and speed in each phase such as attack and decay, and cutoff frequency. , Filter control information (TI) such as resonance (increased level of resonance part),
There is other effect information (EI) such as pan effect and reverberation effect. This information is assigned to the CPU 1 by key assignment,
It is updated at any time according to the pronunciation control.

The waveform read address generator 21, which will be described later, is based on the parameters given from the CPU 1.
It is a circuit for calculating the read address RA of the waveform memory. When the reading from the waveform memory reaches the end of one waveform data, the waveform read address generator 21 returns to a predetermined address and repeatedly reads, or reads in a reverse direction to a predetermined address and changes the direction again. The generation of long musical tones is controlled by a method such as reading to the end.

FIG. 6 is an explanatory diagram showing a method of reading data from the waveform memory. (A) shows a method of returning to a predetermined address and reading repeatedly. When reading is started from a start address ST, and when an end address LE is reached, it returns to the repetition start address LT and continues reading in the same direction.

In FIG. 6B, when the end address LE is reached, reading is performed in the reverse direction from the end address LE this time, and when the repeat start address LT is reached, the direction is changed again and reading is continued. The present invention can be implemented in any system, but the system of (a) will be described as an example.

Returning to FIG. 2, the waveform read address generator 21 also includes a modulation effect signal generation circuit for eliminating monotonicity in the repeating period, which is a characteristic part of this embodiment. This will be described later.

The waveform memory 22 stores PCM recording of musical tones of various tones such as a piano and processes the data. The waveform memory 22 stores the integer part of the read address RA designated by the waveform read address generator 21. The waveform data of the address is output to the interpolation circuit 23. Since data is repeatedly or repeatedly read out, noise is not generated due to abrupt changes in the waveform data at the repeating portion or the folding portion. For example, the waveform data at both the repeating portion and the folding portion becomes 0. Perform such processing.

The interpolator 23 includes waveform data of the fractional part of the read address RA output from the waveform read address generator 21 and the integer part of the read address RA read from the waveform memory 22, and (the read address RA It is a circuit for obtaining an accurate value by calculation from the waveform data of the address of the integer part of +1).

The digital filter 24 is for adjusting the frequency component of the generated tone signal, and based on the control signal from the filter control signal generator 25, cutoff frequency, resonance (increased level of resonance part). ) And other characteristics are controlled.

The filter control signal generator 25 calculates the output information (TI) from the parameter memory 20 and the modulation signal (TD) from the waveform read address generator 21,
The control signal is output to the digital filter 24.

The envelope generator 26 generates an envelope based on the modulated signal (AD) from the parameter memory 20 and the waveform read address generator 21, and the multiplier 27 outputs the envelope to the output of the digital filter 24. Multiply the outputs.

FIG. 5A is a block diagram showing an example of the envelope generator 26. This envelope generator uses the parameter memory 2 according to the key-on / off information.
Based on the data AI from 0, the envelope generator 5
0 generates an envelope, and the envelope signal and the modulation signal AD output from the waveform read address generator 21 are multiplied by the multiplier 51 to perform modulation.

FIG. 5B is a block diagram showing another configuration example of the envelope generator 26. This envelope generator multiplies only a part of the data AI from the parameter memory 20, for example, the sustain parameter, by the modulation signal AD output from the waveform read address generator 21 by the multiplier 52, and based on this parameter, The envelope generator 50 generates an envelope. Therefore, the envelope generator modulates only the sustain portion of the envelope signal.

Returning to FIG. 2, the pan effect adding circuit 28 is
One tone signal for each channel, left and right at given ratio
The sound image (the position of the sound source) for each musical sound is controlled by distributing and outputting the two musical sound signals. The pan control signal generator 29 calculates the modulation information (ED) from the parameter memory 20 and the waveform read address generator 21, and generates a control signal to the pan effect adding circuit 28.

FIG. 3 shows a waveform read address generator 21.
It is a block diagram showing the internal structure of. This address generator shows an example of the method of FIG. 6A, in which when the read address reaches the end address, the read address is repeatedly returned to the start address and the read operation is continued in the same direction.

The first adder 30 adds the key number which is the pitch information and the output (FD) of the modulation effect memory 40. Also, if necessary, frequency modulation effect (vibrato,
The modulation effect signal E may be added to generate (portamento, etc.). The adder may be provided after the frequency number memory 31.

The frequency number memory 31 inputs the output of the first adder 30, which is pitch information, as an address,
The frequency number which is the address interval to be read from the waveform memory 22 is output. In order to express the modulation effect in detail, the key number is composed of a note representing chromatic scale information and a fractional cent. Therefore, the frequency number memory 31
Stores, for example, a frequency number corresponding to a key number obtained by further dividing a chromatic scale into 100 equal parts. The frequency number also consists of an integer part and a decimal part.

The rising detector 32 detects the rising of the key-on / off signal, that is, the time when the key is turned on, and detects 1
The signal is output only during the clock period. First selector 33
Is inserted in the read address accumulating circuit of the waveform memory, outputs the read start address ST while the output signal of the rising edge detector 32 is present, and outputs the signal from the second selector 38 during other periods. Output. By this selector, the read start address ST is input to the address accumulation circuit (holding unit 35) at the start of sound generation.

The second adder 34 calculates the address RA to be read next by adding the outputs of the first selector 33 and the frequency number memory 31. This value is output to the waveform memory 22 and the interpolation circuit 23. The holder 35 is a storage device for the number of channels, and holds the read address RA accumulated by the second adder 34 according to a clock (not shown).

The comparator 36 subtracts the read end address LE from the read address RA accumulated by the second adder 34, and when the condition (RA ≧ LE) is satisfied, the read address exceeds the end address. The arrival signal indicating that is output to the counter 39 and the second selector 38 for a certain period. Further, the over value (RA-LE) is output to the third adder 37 for a certain period.

The third adder 37 receives the overvalue (R
A-LE) and the repeat start address LT are added.
The second selector 38 normally outputs the signal from the holder 35, but when the arrival signal is generated from the comparator 36, it outputs the input from the third adder 37.

The counter 39 is for detecting and displaying that the repetitive reading period has started. The counters 39 are provided for the number of channels, are reset by the output signal of the rising detector 32, and count up by the arrival signal from the comparator 36. By this operation, as shown in FIG. 6A, the number of repetitions of reading from the waveform memory is counted.

The modulation information memory 40 inputs the count value of the counter 39 as an address and outputs a modulation signal to each circuit. The output signal is, for example, the digital filter 2
Signal TD for modulating four, envelope generator 26
Signal AD for modulating signal, signal ED for modulating other effect adding circuit, waveform read address generator 2
1 is a signal FD for modulating 1.

FIG. 7 shows the modulation information memory 4 from the start of sound generation.
It is a waveform diagram which shows an example of the output waveform of 0. In the figure, the output of the modulation information memory 40 is 0 because the repetition area has not been reached for a predetermined period from the start of sound generation.
When the repetitive area is entered after the lapse of a predetermined period, the counter starts counting up, and the modulation information memory 4
The output of 0 changes as shown in the figure.

In the case of this example, a sine wave whose amplitude gradually increases is shown. For example, by using this signal as FD, AD, etc., the tone signal can be slightly changed to eliminate monotonicity. . In addition to this, an arbitrary waveform can be considered as the waveform. For example, as the signal TD for modulating the digital filter 24, if a signal that monotonically decreases is generated and the cutoff frequency is controlled using this, the time As a result, a tone signal with less harmonic components is obtained. Returning to FIG. 3, the signal FD is added to the first adder 30 and the frequency of the tone signal is modulated.

Next, another configuration example of the counter 39 of FIG. 3 will be described. The counter 39 in FIG. 3 counts up each time the read address reaches the end address, but the individual waveform data have different lengths of the data repeat portion, and even when the same waveform data is read. , The reading speed differs depending on the pitch. Therefore, the count cycle of the counter 39 may vary depending on the type of waveform and pitch, and the modulation signal may vary.

The counter configuration example shown in FIG. 4 is an improvement of the above problems. The arrival signal of the comparator 36 in FIG. 3 is connected to the set input terminal of the RS flip-flop 41, and the output of the rising edge detector 32 is connected to the reset input terminal. The inverted output of the RS flip-flop 41 is the counter 43 and the DCO.
It is connected to the reset terminal of the (digital control oscillator) 42, and the output of the DCO 42 is connected to the clock terminal of the counter 43. The DCO 42 is external (eg CP
From U1), the oscillation frequency can be preset.

With this configuration, after the read address reaches the end address and enters the repeat area,
Since the counter 43 counts up at a constant cycle based on the oscillation frequency of the DCO 42, the modulation signal will not vary depending on the type of waveform and pitch.

Next, the operation of the above embodiment will be described with reference to FIGS. When the performer presses the keyboard,
CPU 1 of the above performs key assignment processing by a known method,
The tone color information is written in the area of the corresponding channel of the parameter memory 20. Further, the pitch information is given to the waveform read address generator 21, and the waveform read address generator 21 and the envelope generator 26 are activated.
This starts sounding.

When the reading of the waveform memory reaches the end of the waveform data, the comparator 36 of FIG. 3 outputs an arrival signal, the read address AD is reset to (repeat start address LT + over value), and the counter 39 Will count up. This operation is repeated every time the reading of the waveform memory reaches the end of the waveform data, as shown in FIG.

Then, as shown in FIG. 7, various modulation signals (TD, AD, ED, FD) corresponding to the count value of the counter 39 are output from the modulation information memory 40, and the frequency and the harmonic of the tone signal are output. The wave component ratio, amplitude, sound image, reverberation, etc. are modulated. By such an operation, the generated musical sound is slightly changed, so that monotonicity cannot be felt.

Although one embodiment has been described above, the present invention detects the repeated read period of the waveform memory and applies various modulation effects to the musical tone signal. The type of effect is, for example, a reverberation effect. Various things are possible.

As the detection means for detecting the start of the repeated read period, an example using a counter is shown, but a flip-flop or a flag is simply used to indicate that it is within the period, and a normal modulation effect is obtained. It is also possible to apply modulation by using an addition means. Also,
As for the means for applying the modulation effect to the musical tone signal, the example in which the modulation signal is generated by using the memory has been shown, but the modulation signal can be generated by the gate circuit or the analog circuit.

Further, although the present embodiment discloses that the generation control of the modulation signal is performed by hardware, it is also possible to perform the control by software including the detection of the repeating period. In this case, timbre control information is calculated in combination with control of modulation effects such as vibrato, which is not shown,
It is also possible to control each signal generator via the parameter memory 20.

[0045]

As described above, according to the present invention, since the generated musical tone is subtly changed, monotone is not felt and it is possible to generate a musical tone close to that of an actual musical instrument. There is an effect that.

[Brief description of drawings]

FIG. 1 is a block diagram showing a hardware configuration of an electronic musical instrument to which the present invention is applied.

FIG. 2 is a block diagram showing an internal configuration of a musical sound generating section 6.

FIG. 3 is a block diagram showing an internal structure of a waveform read address generator 21.

FIG. 4 is a block diagram showing another configuration example of the counter 39 of FIG.

FIG. 5 is a block diagram showing a configuration example of an envelope generator 26.

FIG. 6 is an explanatory diagram showing a method of reading data from a waveform memory.

7 is a waveform diagram showing an example of an output waveform of the modulation information memory 40. FIG.

[Explanation of symbols]

1 ... CPU, 2 ... ROM, 3 ... RAM, 4 ... Keyboard section, 5 ... Operation panel section, 6 ... Musical sound generating section, 7 ... D / A converter, 8 ... Analog signal processing section, 9 ... Amplifier, 10 ... Speaker ... 11 ... Bus 20 ... Parameter memory, 21 ... Waveform read address generating section, 22 ... Waveform memory, 23 ... Interpolation circuit, 24 ... Digital filter, 25 ... Filter control signal generator, 26
... Envelope generator, 27 ... Multiplier, 28 ... Pan effect adding circuit, 29 ... Pan control signal generator

Claims (3)

[Claims] 1. An electronic musical instrument having a waveform memory, wherein musical tone waveforms are sequentially read from the waveform memory, and when the end of the waveform is reached, the electronic musical instrument that repeatedly generates a musical tone by repeatedly reading a predetermined section enters a repeated reading period. An electronic musical instrument comprising: a detection means for detecting the above; and a means for applying a modulation effect to a tone signal in accordance with the output of the detection means. 2. The detecting means outputs the number of repetitions of waveform reading.
Electronic musical instrument described in. 3. The electronic musical instrument according to claim 1, wherein the detecting means outputs the elapsed time after the repeated reading period.