JPH0258637B2 - - Google Patents

Description

[Detailed Description of the Invention] (1) Technical Field of the Invention The present invention stores frequency information corresponding to each key, reads out and accumulates this content, and generates a designated duty width value based on the accumulated result. The present invention relates to a device for generating a frequency modulation effect in an electronic musical instrument that outputs scale pulses having various duty widths.

(2) Prior Art and Problems Conventionally, a memory is provided in which a frequency number, which is frequency information corresponding to each key, is stored in advance, and a key code formed according to a predetermined pressed key is used as an address. Read out the frequency number,
An electronic musical instrument is used in which the read frequency numbers are accumulated by an accumulator, and based on the accumulation result, a memory in which musical sound waveforms are stored in advance is sampled to obtain a desired pitch musical waveform signal. Furthermore, in order to obtain a desired musical tone, an electronic musical instrument that uses the Fourier method to calculate the amplitude value at each sampling point based on the cumulative result, or a memory that stores waveforms obtained using an arithmetic method, is used.
Electronic musical instruments and the like have been proposed that obtain a desired high pitch sound waveform signal by sampling based on the cumulative result.

These electronic musical instruments require a large amount of memory to store musical waveforms for each tone or for each tone sequence multiplied by the number of simultaneous pronunciations, and arithmetic circuits for creating desired waveforms by calculations such as the Fourier method. Depending on the number of samplings, a very large number of circuits, such as circuits for interpolating between sampling points, are required. On the other hand, there has been a desire to realize an electronic musical instrument that basically uses the above-mentioned storage accumulation method and that effectively reduces memory and arithmetic circuits so as to be suitable for small and popular electronic musical instruments.

In contrast, in a separate application, the present applicant accumulates the frequency numbers read out according to the pressed keys, and compares the accumulated results with the designated duty width value. We proposed a method for outputting scale pulses with various duty widths. Subsequently, studies were conducted on devices that would generate frequency modulation effects such as vibrato, delay vibrato, and glide for this type of electronic musical instrument.

(3) Purpose of the Invention The purpose of the present invention is to store frequency information corresponding to each key, read out and accumulate this content, and generate a designated duty width value based on the cumulative result.
It is an object of the present invention to provide an electronic musical instrument that outputs scale pulses with various duty widths and is equipped with a device that generates a simpler and more effective frequency modulation effect.

(4) Structure of the Invention In order to achieve the above object, the electronic musical instrument of the present invention includes a storage means for storing frequency information corresponding to each key in advance, and a storage means for reading out and accumulating the stored frequency information according to the pressed key. a pulse width specifying means that takes key, tablet, and envelope information as input and generates a pulse width specified value related to the input; and pulse width specifying means that receives key, tablet, and envelope information from the pulse width specifying means. a modulated output generating means for outputting two time-varying values based on specified values; and comparing each of the output values from the modulated output generating means with the accumulated value from the accumulating means, and generating a comparison output for each. and a mixing means for obtaining a logical product of the respective comparison outputs from the comparing means, the mixing means outputting a scale pulse specified by the pulse width specification value having a frequency modulation effect from the mixing means. It is characterized by the fact that it occurs.

(5) Embodiments of the Invention Figures 1a to 1c are explanatory diagrams of the principle of the main parts of the above-mentioned proposed example to which the present invention is applied.

As mentioned above, the frequency number corresponding to the pressed key is read out from the memory in which the frequency number, which is the frequency information corresponding to each key, is stored in advance, using the key code formed according to the pressed key as an address, The read frequency numbers are accumulated by an accumulator. In the present invention, the accumulation result is not sampled from the memory as in the past to obtain the desired pitch sound waveform, but by comparing the accumulation result with the duty width specified value introduced in the proposed example. , obtain the corresponding scale pulse. A musical sound waveform is then created by passing the obtained scale pulse through a timbre filter to produce a desired musical tone.

That is, as shown in FIG. 1 a, a duty width designation value that differs depending on the range is sent from a duty width designator (described later) based on the key information representing the range of the key, which is then input into a comparator and compared with the cumulative value. Then, the comparator outputs a scale pulse having a scale frequency with a duty width that differs depending on the range.

In Figure b, a duty width specified value that differs depending on the selected tone tablet information is sent out and inputted into a comparator, and the comparator outputs a scale frequency with a duty width that differs depending on the tablet. Outputs a scale pulse.

In the figure c~, a duty width designation value that changes over time is sent from the duty width designator based on the envelope information that changes over time, it is input into a comparator, and from the comparator, a duty width designation value that changes over time is sent out. Outputs a scale pulse with a scale frequency that is the duty width.

In this way, scale pulses can be output with a simple configuration without using a large amount of memory or arithmetic circuits from the accumulated values, and therefore it can be applied to small or popular electronic musical instruments.

FIG. 2 is a configuration explanatory diagram of an embodiment of the present invention,
This is a block diagram of a basic musical tone generator 100.

In the figure, key/tablet switch group 1
By pressing 01, key/tablet assigner 1
02 assigns the open/closed state of the key/tablet,
Then, key information and tablet information are sent to the necessary blocks. The frequency number memory 104 stores a frequency number, which is frequency information corresponding to a key on the keyboard, and receives a key code of the key information that is pressed and assigned to the key/tablet assigner 102, and inputs the key code to that key code. The corresponding frequency number is selected and output. The selected frequency number is used as one input of the adder 105, and the added data from the adder 105 is sent to the latch circuit 1.
06 and is latched by the clock pulse from the system clock circuit 103, and its output is fed back and added as the other input of the adder 105. In this manner, adder 105 and latch circuit 106 operate as an accumulator that accumulates selected frequency numbers by clock pulses. One of the outputs of the latch circuit 106 is input to the adder 105, and the other is input to the comparator 107 ₁ ,
107 ₂ input. Comparators 107 ₁ , 107 ₂
are output by modulator 120 a,b(b>
In response to a), each comparator ₁₀₇₁ compares the outputs f and b of the latch circuit 106 and operates to output "1" if f≦b.
₂ operates to output "1" when a≦f. Each output of the comparators 107 ₁ and 107 ₂ is input to the mixer 121, and the mixer 121 inputs the outputs of the comparators 107 1 and 107 2 to the mixer 121.
It operates to output "1" when both ₁ and 107 ₂ are "1". The modulator 120 is a pulse width designator 1
Pulse width designation signal c that determines the pulse width by 08
Then, the pulse width designation signal c is input as key information.
It operates to receive tablet information and information from the envelope generator 109 and perform modulation.

Next, using FIG. 3 a to d, the comparators 107 ₁ , 1
07 ₂ , mixer 121, modulator 120, and pulse width designator 108 will be explained in detail. From the latch circuit 106, as shown by f in FIG.
A sawtooth waveform that repeats in response to key presses is output. C in the figure a is output from the pulse width designator 108, and becomes information for determining the pulse width shown in the figure d, which is the output of the mixer 121. Comparator 107
₁ is a latch circuit 1 which receives the output b of the modulator 120.
It compares the outputs f and b of 06 and operates to output “1” when f≦b and “0” when f>b, outputting a waveform like b in the same figure. . The other comparator ₁₀₇₂ receives the other output a (b>a) of the modulator 120, compares the output f of the latch circuit 106 with a, and outputs "1" when a≦f, and when a>f When , it operates to output "0" and outputs a waveform as shown in c in the same figure.

Next, as shown in b and c of the same figure, the comparator 107 ₁
The outputs of and 107 ₂ are input to mixer 121, respectively. In the mixer 121, comparators 107 ₁ , 10
7 and ₂ respectively, and operates to output "1" when both are "1" and output "0" in other cases, outputting a waveform as shown in d of the same figure. Here, in the figure, a', b' indicate time values corresponding to amplitude values a, b=a+c compared with f.

Next, a method for obtaining the frequency effect, which is the main part of the present invention, will be described using the embodiment shown in FIG.

Figure 4 a and b are the waveform diagrams.
is a latch circuit 10 having a period T corresponding to a key press.
The output f of 6 is shown.

Next, the pulse width c is input to the modulator 120 designated by the pulse width designator 108 . Modulator 120 receives key information from key/tablet assigner 102, tablet information, or information from envelope generator 109 and sets the value of a and b=
It operates to change the value of a+c over time. Therefore, a becomes a comparison standard with the output f of the latch circuit 106 in the comparators 107 ₁ and 107 ₂ .
Or the value of b changes. As a result, mixer 12
₁ , the period T of the sawtooth waveform output f shown in _FIG . changes. That is, by increasing the value of a with time while keeping the frequency of the output f of the latch circuit 106 constant, the frequency decreases, and then by decreasing the value of a with time,
A frequency effect can be obtained in which the frequency of the output of the mixer 121 becomes higher.

Therefore, the key/tablet assigner 102 provides information for adding a vibrato effect, that is, information as shown in FIG. Upon receiving the output c from 108, modulator 120 sets a=
It operates to output Asinωt,b = Asinωt+c.

FIG. 6a shows a specific circuit example of the modulator 120 for adding the vibrato effect. Modulator 12
0 receives information about the depth A and the vibrato speed ω from the key/tablet assigner 102, and the modulated wave generator ₁₂₀₁ generates Asinωt. This output
Asinωt is split into two branches and one is output as a,
The other signal is input to the adder 120 ₂ , where it is added to the output c of the pulse width designator 108 and then output as the other output b.

The outputs a and b of this modulator 120 are output to the comparator 107
₁ and 107 ₂ , respectively. As a result, the period of the output of the mixer 121 changes with time, as shown in FIG. 4b, and as a result, the frequency changes with time, making it possible to obtain a vibrato effect.

Next, explaining the delay vibrato effect, in the same way as the method for obtaining the vibrato effect described above, information for adding the delay vibrato effect by the key/tablet assigner 102, that is, the delay time d, the vibrato depth A, In response to the information shown in FIG. 5b consisting of the velocity ω and the output c from the pulse width designator 108, the modulator 12
0 is a=A(t-d)×Sinω(t)t, b=A(t
−d)×Sinω(t)t+c.

FIG. 6b shows a specific circuit example of the modulator 120 for adding the delay vibrato effect. The modulator 120 receives the vibrato depth A(t) and vibrato speed ω from the key/tablet assigner 102.
(t), is delayed by the time d by the delay circuit 120 ₃ upon receiving the information of the delay time d, and the delay circuit 1
The output of 20 ₃ becomes A(t-d), ω(t-d) and is input to the modulated wave generator 120 ₁ , and similarly to a in the figure, a=A(t-d)×sinω(t)t, b=A(t-b)
×sinω(t)t+c is output.

These outputs a and b are input to comparators 107 ₁ and 102 ₂ , respectively. As a result, a pulse waveform having a delay vibrato effect can be obtained as the output of the mixer 121.

Next, we will discuss the glide effect. Information for obtaining the glide effect by the key/tablet assigner 102, namely frequency displacement p, time t,
In response to the information as shown in FIG. Change the output as shown in the same figure, a=q(t), b=q
Comparator 107 ₁ , 1 as (t)+c, q(o)=p
07 ₂ , respectively. As a result, a glide effect can be obtained as the output of the mixer 121.

Regarding each frequency effect, the output c of the pulse width designator 108 has been treated as a constant value, but it is possible to change the pulse width by changing the value of c, and it is also possible to change the value of c with time. By changing the frequency, the pulse width can be changed at the same time.

In FIG. 2, one set of comparators 107 ₁ , 10
7 ₂ , the modulator 120, and the mixer 121. By using a plurality of sets of these, different frequency effects can be generated independently for each set and combined.

Returning to FIG. 2, the output of mixer 121 is input to envelope adder 110, where an envelope is added using an envelope signal from envelope generator 109, which takes in key information and tablet information and generates a desired envelope. Ru. Thereafter, the output of the envelope adder 110 is passed through a timbre filter 111 to form a desired musical sound waveform based on the tablet information, and the musical sound waveform is sent to a sound system 112.

(6) Effects of the Invention As explained above, according to the present invention, frequency information corresponding to each key is stored, this content is read out and accumulated, and the accumulated value and the duty width from the duty width specifying means are calculated. In an electronic musical instrument that outputs scale pulses having various duty widths by comparing a specified value with a specified value, the duty width specifying means includes a pulse width specifying means for specifying a pulse width, and a duty width during a period including the pulse width. An electronic musical instrument is realized which is composed of a key, a tablet, and a modulation means for temporally changing the amplitude using envelope information. As a result, it is possible to obtain scale pulses corresponding to a musical tone waveform with a simple configuration, and it is also possible to add various frequency effects to the musical tone waveform with a configuration adapted to this.

[Brief explanation of the drawing]

Figs. 1 a to c are principle explanatory diagrams of the main parts of a proposed example to which the present invention is applied, Fig. 2 is a configuration explanatory diagram of an embodiment of the present invention, Figs. 3, 4, and 5 a to c 6A and 6B are concrete circuit examples of the main parts of the embodiment. In the figure, 101 is a group of key/target switches, 102 is a key/target assigner, and 103 is a key/target assigner group. is the system clock circuit, 10
4 is a frequency number memory, 105 is an adder, 10
6 is a latch circuit, 107 ₁ and 107 ₂ are comparators, 1
08 is a pulse width designator, 109 is an envelope generator, 110 is an envelope adder, 111 is a tone filter, 112 is a sound system, 120
is a modulator, and 121 is a mixer.

Claims (1)

[Scope of Claims] 1. Storage means for pre-storing frequency information corresponding to each key; Accumulation means for reading out and accumulating the stored frequency information in accordance with the pressed keys; Key, tablet and envelope information. a pulse width designation means for generating a pulse width designation value associated with the input; and two time-varying values based on the pulse width designation value from the pulse width designation means using key, tablet, and envelope information. a modulated output generating means for outputting; a comparing means for comparing each of the output values from the modulated output generating means with an accumulated value from the accumulating means and outputting a respective comparison output; and each from the comparing means. An electronic musical instrument comprising: mixing means for obtaining a logical product of comparison outputs; and generating a scale pulse specified by the pulse width specified value having a frequency modulation effect from the mixing means. 2. The electronic musical instrument according to claim 1, wherein the pulse width designation means further temporally changes the pulse width designation value generated by the means based on key, tablet, and envelope information. .