JP2751598B2 - Waveform signal output device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a waveform signal output device that circulates an input signal in a circulation path including a forward path and a return path, and outputs a waveform signal simulating a propagation state of a sound wave in a tubular body such as a wind instrument.

[Prior art]

Conventionally, this type of apparatus has a signal transmission means between a plurality of signal transmission means having a delay means and constituting a forward path and a return path of a signal, as shown in, for example, JP-A-63-40199. A plurality of connection means for connecting the forward path and the return path with each other, inputting a predetermined amount of the signal on the forward path to the return path according to a predetermined reflection coefficient, and inputting a predetermined amount of the signal on the return path to the forward path. It constitutes a signal transmission path. Then, the predetermined excitation signal is nonlinearly converted, and the excitation signal after the non-linear conversion is input to the transmission path and circulated in the transmission path, thereby generating a musical tone close to the natural musical instrument by imitating the sounding process of the natural musical instrument. doing.

[Problems to be solved by the invention]

The tone color of the tone generated by the conventional waveform signal output device is controlled by the conversion characteristic in the non-linear conversion, the reflection coefficient, or the characteristic of the filter provided at the end of the transmission line. It was difficult to generate the desired nonharmonic overtones. The present invention has been made in order to address the above problem, and a waveform signal output device that circulates an input signal through a circulation path including an outward path and a return path to output a waveform signal having a predetermined frequency characteristic. It is an object of the present invention to provide a waveform signal output device for more easily controlling a frequency component included in a signal to obtain a tone having a desired frequency component.

[Means for Solving the Problems]

In order to achieve the above object, the configuration of the present invention is characterized in that a first path and a second path for transmitting a waveform signal are provided with delay means interposed in at least one of the same path and the return path. Is connected between the first signal transmission means and the return path of the first signal transmission means from the outward path of the first signal transmission means and the second signal transmission means.
Connection for transmitting a signal to the outward path of the second signal transmission means and transmitting a signal from the return path of the second signal transmission means to the outward path of the second signal transmission means and the return path of the first signal transmission means. Means for outputting a waveform signal having a predetermined frequency characteristic based on an input signal, wherein said first signal transmission means is provided in said connection means from an outward path of said first signal transmission means. The frequency characteristics of the signal transmission to the forward path of the second signal transmission means and the frequency characteristics of each signal transmission to the outward path of the second signal transmission means are different from each other, and the outward path of the second signal transmission means and the first signal path from the return path of the second signal transmission means. In this case, a filter is provided which makes the frequency characteristics of each signal transmission to the return path of the signal transmission means different from each other.

Effect of the Invention

In the present invention configured as described above, the connecting means is interposed between the first and second signal transmitting means having the delay means, and the excitation is performed in the circulating path including the outward path and the returning path in both signal transmitting means. When the signal is repeatedly circulated to simulate a wind tube or the like in a wind instrument or the like, the connecting means connects the return path of the first signal transmission means and the second signal from the outward path of the first signal transmission means by the action of a filter. The frequency characteristics of each signal transmission to the outward path of the transmission means are made different, and each signal transmission from the return path of the second signal transmission means to the outward path of the second signal transmission means and the return path of the first signal transmission means. Have different frequency characteristics. Thereby, the signal that has propagated on the outward path of the first signal transmission means is converted to the first signal according to the frequency component included in the signal.
Of the second signal transmission means or the outward path of the second signal transmission means. On the other hand, the signal that has propagated on the return path of the second signal transmission means is guided to the outward path of the second signal transmission means or returns to the return path of the first signal transmission means according to the frequency component included in the signal. Or be led. This means that when the excitation signal is repeatedly circulated through the first and second signal transmission means, some frequency components of the circulating signal circulate in a circulation loop including only the first signal transmission means, This means that some other frequency components circulate in a circulating loop including both the first and second signal transmission means, and are composed of the first and second signal transmission means connected by the connection means. The circulation path is equivalent to having a plurality of different circulation paths depending on the frequency.

【The invention's effect】

As described above, the first and second embodiments of the present invention are described.
Since the circulating path including the signal transmission means is equivalent to having a plurality of different circulating paths depending on the frequency, it is possible to predict the frequency component of the circulating signal formed in the circulating path, The control of harmonic components is facilitated according to the above, and a waveform signal whose frequency characteristics are delicately controlled can be obtained from the waveform signal output device according to the present invention,
The use of this device makes it possible to make fine tone settings.

【Example】

Hereinafter, embodiments of the present invention will be described with reference to the drawings. First
FIG. 1 shows an overall schematic configuration of an electronic musical instrument provided with a waveform signal output device according to the present invention. In this electronic musical instrument, a parameter forming circuit 200 forms parameters for forming a tone signal based on operation signals corresponding to various operations by the tubular operator 100, and a signal forming circuit 400 generates a tone signal based on the parameters. To form The electronic musical instrument is played by a tubular operator 100 shown in FIG. The tubular operator 100 has a mouthpiece section 110, an operation section 120, and an operation detection section 130.
The cantilever detects the pressing force of the lead (not shown)
111 and a pressure sensor 112 for detecting the pressure of the airflow blown into the mouthpiece unit 110.The operation unit 120 is provided with a key switch 121 including a main key switch and an auxiliary key switch. A micro unit 130 outputs a key-on signal KON, a key-off signal KOF, a press signal BR, a pitch bend signal PB, and a key code signal KC representing each operation based on the detection results of the cantilever 111, the pressure sensor 112, and the key switch 121. A computer 131 is provided (see FIG. 3). The parameter forming circuit 200 forms an intraoral pressure signal PRES representing the intraoral pressure (blowing pressure) based on the breath signal BR, and an embouchure signal EMBS representing the lip holding or tightening based on the pitch bend signal PB. Based on the key-on signal KON and the key-off signal KOF, the output of the formed intraoral pressure signal PRES and the embouchure signal EMBS is turned on / off. Further, the parameter forming circuit 200
Based on the key code signal KC, it outputs delay stage number signals n1, n2 and reflection coefficient signals K1, K2 to the signal forming circuit 400. As shown in FIG. 1, the signal forming circuit 400 includes an excitation signal forming section 410 for forming an excitation signal, a waveform signal loop section 420, and a tube simulating section 430. Simulates the generation of sound waves due to lead vibration, and the waveform signal loop section 420 simulates the generation of pressure as a combination of the incident wave due to lead vibration and the reflected wave from the resonance tube. At 430, the shape of the resonance tube is simulated. Excitation signal forming section 410 adds adder 411 for obtaining a pressure difference between the intraoral pressure and the reflected wave from the resonance tube (subtraction is performed by inverting the sign bit), and cuts a high-frequency component as a characteristic with respect to the pressure of the lead. Low-pass filter 412
And an adder 413 for applying the pressing force of the lip or the like to the pressure output by the filter 412, and a non-linear conversion of the output of the adder 413 to obtain an amount relating to the flow path area between the lead and the mouthpiece. A nonlinear conversion circuit 414, a multiplier 415 for sign-converting the pressure difference, a multiplier 416 for multiplying the pressure difference after the sign conversion and the flow area to obtain a flow velocity, and multiplying the flow velocity by a resistance component. And a multiplier 417 for obtaining the sound pressure, and inputs an excitation signal representing the same sound pressure to the tube simulation unit 430 via the waveform signal loop unit 420. The waveform signal loop unit 420 inputs the waveform signal of the signal line L2 to be the return path to the signal line L1 to be the forward path and the adder 421 to input the waveform signal of the signal line L1 to be the return path to the signal line L2 to be the return path. An adder 422 is provided, and the output of the adder 421 is used as the output of the waveform signal output device. The tube simulating unit 430 forms a ladder-like circuit 431 in which a pair of delay circuits SR1 (1a, 1b) and SR2 (2a, 2b) are connected in two stages via a junction J. Connected to the lines L1 and L2, and the ladder circuit 431
At the end of the control signal C output from the parameter forming circuit 200
A low-pass filter 432 that simulates the form of the resonance tube according to the OEF and a multiplier 433 that forms a reflected wave input to the return path according to the multiplication coefficient (−G) output from the parameter forming circuit 200 are connected. Body (hereinafter, this tube is referred to as a section).
The main tube is called a tube. Simulate). The shift register SR1 (1a, 1
b), SR2 (2a, 2b) are for simulating the delay situation in each section constituting the tube body, and are performed in accordance with the delay stage number signals n1, n2 formed by the parameter forming circuit 200. Give the delay time corresponding to the length. Note that n
1, n2 is set as 1: 3. Also, the shift registers SR1, S
The junction J connected between R2 simulates the reflection occurring between the sections, and is input from the forward path on the shift register SR1a side when connecting the forward path and the return path between the respective shift registers SR1 and SR2. Part of the signal is input to the return path on the shift register SR1b side, and part of the signal on the return path on the shift register SR2b side is input to the outward path on the shift register SR2b side. Note that, as shown in FIG. 1, the shift register can be provided on each of the forward path and the return path of the signal, or can be collectively disposed on either the forward path or the return path. In the case where the signal is installed on each of the forward path and the return path, the number of delay stages in the case where the signal is combined into one of the forward path and the return path is half. The junction J is specifically configured as shown in FIG. 6, but basically, as shown in FIG. 4, a Kelly-type device comprising a multiplier and an adder capable of changing a multiplication coefficient K. This is a Kelly-Lochbaum type multiplication lattice, and reproduces a reflection state at a connection portion of each section by a reflection coefficient K formed by the parameter forming circuit 200. The Kelly-Rockbaum type multiplication lattice shown in FIG. 4 is equivalent to the lattice shown in FIG. 5 by adjusting the multiplication coefficient in each multiplier. Junction J has a basic configuration of the lattice shown in FIG. 6 and is input from the input terminal A on the outward path and the input terminal D on the return path, and outputs the cyclic signal added by the adder 431J1 via the multipliers 431J5 and 413J6. The signal is input to the filter 431J2, and the output of the filter 431J2 is output to the output terminal C on the forward path and the output terminal B on the return path via adders 431J3 and 431J4. The filter 431J2 is composed of a low-pass filter. If the filter is an ideal low-pass filter as shown in FIG. 7, the junction J is shown in FIG. 8 for a circulating signal whose frequency is equal to or lower than the cutoff frequency fc. In a circulating signal whose frequency is equal to or higher than the cutoff frequency fc, the junction J is divided as shown in FIG. At this time, from the polarity of the signal input from the forward path to the return path and from the return path to the forward path, the split state actually represents a state in which the pipe is closed. Next, the operation of the present embodiment configured as described above will be described. When the player starts playing using the tubular operator 100, the microcomputer 131 of the operation detecting unit 130 forms and outputs various operation signals corresponding to the operation states of the cantilever 111, the pressure sensor 112, and the key switch 121. Among them, the press signal BR and the pitch bend signal PB are converted into an intraoral pressure signal PRES and an embouchure signal EMBS by a predetermined conversion table in the parameter forming circuit 200, and correspond to the key-on signal KON and the key-off signal KOF only during key-on. Output to forming circuit 400. Therefore, when the performance is started, the mouth pressure signal PRES and the embouchure signal EMBS are input to the signal forming circuit 400,
An excitation signal indicating the pressure of the incident wave is formed by an excitation signal forming section 410 in the same circuit, and is input from the waveform signal loop section 420 to the tube simulation section 430. On the other hand, the key code signal KC
Is also input to form delay stage number signals n1 and n2 corresponding to the key code signal KC and to form predetermined reflection coefficient signals K1 and K2. When the delay stage number signals n1, n2 and the reflection coefficient signals K1, K2 are output to the shift registers SR1 (1a, 1b), SR2 (2a, 2b) and the junction J in the tube simulation unit 430, simulation is performed. A circulation path with a delay time corresponding to the entire length of the tube is formed, and the changing state of the section is reproduced by the junction J.
Then, when an incident wave is input from the excitation signal forming unit 410 to the tube simulating unit 430 via the waveform signal loop unit 420, the incident wave is transmitted to the signal path L1 in the tube simulating unit 430.
Start circulating through the signal path consisting of L2. By the way, the circulation path in the pipe simulation unit 430 includes a shift register SR1a, a junction J, a shift register SR2a, a low-pass filter 432, a multiplier 433, a shift register SR2b, a junction J, and a shift register.
Along with a first circulation path LOOP1 composed of SR1b, a second circulation path LOOP2 composed of a shift register SR1a, a junction J and a shift register SR1b, a shift register SR2a, a low-pass filter 432, a multiplier 433, a shift register SR2b and a junction J And a third circulation path LOOP3 consisting essentially of the first circulation path LOOP3 for the value of the reflection coefficient
The pitch is determined by the delay time in LOOP1. Consider the frequency component of the circulating signal for each circulating path formed here. The total delay time in the first circulation path LOOP1 is the longest, and as shown in FIG. 10, a signal of a frequency component having a relationship of a harmonic of the same frequency with a signal of the lowest frequency corresponding to the total delay time is formed. You. However, the low-pass filter 43
For the frequency component equal to or higher than the cutoff frequency fc of 1J2, the junction J is divided as shown in FIG. 9, and the first circulation path LOOP1 does not exist. Therefore, as shown in FIG. 10, the frequency components of harmonics represented by broken lines do not appear. On the other hand, since the delay time of the shift register SR1 is set to 1/4 of the total delay time, the spectrum diagram of the circulating signal formed in the second circulating path is as shown in FIG.
It should be noted that the third circulation path LOOP3 has no relation to the output musical sound, and therefore the description is omitted. Since the tone waveform signal output from the waveform signal loop unit 420 is a composite of the circulating signals in the first circulating path LOOP1 and the second circulating path LOOP2, FIG. 13 is referred to with reference to FIGS. It has the frequency components shown in the figure. That is, as in the present embodiment, the junction J
By providing a filter, the frequency component of the circulating signal formed in each circulating path can be predicted, and the timbre can be easily set. For example, when setting the tone, it is easy to make the delay time in the shift register SR1 slightly shifted from 1/4 of the total delay time, and to generate anharmonic overtones above the cutoff frequency fc. The circulating signal obtained in this way is a waveform signal loop part.
The signal is output to the outside from the output terminal of the adder 421 in 420, and is generated as a musical tone by a sound system (not shown). In the above-described embodiment, a low-pass filter is used as a filter provided for the junction, but another filter may be used. For example, if a high-pass filter is used, the second
A circulation signal is formed in the circulation path of
At fc or more, a circulating signal is formed in the first and second circulating paths. If a band-pass filter is used, the first circulating path and the second circulating path in the pass band, and the second circulating path in the other bands. A circulation signal will be formed in the circulation path. In such cases,
In an actual filter, a frequency component in the pass-stop band remains in the vicinity of the cutoff frequency according to the roll-off characteristic of the filter. Alternatively, an all-pass filter may be used to obtain anharmonic overtones by utilizing the phase (delay) characteristics. Further, by changing the characteristics of the filter over time, the timbre can be changed during the formation of the musical tone. To control the pitch, the delay time of the shift register is changed while maintaining the ratio of the delay time of the shift register SR1 to the total delay time of 1: 4. You may. In the above embodiment, a tube type is used as the operation element, and only the pitch information is output from the operation element. Can also. In this case, a reflection coefficient or the like corresponding to the tube form may be stored. Further, the operator may be other than a tubular type, for example, a keyboard or an automatic performance device.In such a case, as a tone control signal including the embouchure signal EMBS and the mouth pressure signal PRES, performance information, timbre information, Various signals formed based on other information are used. For example, a waveform signal that rises from a musical sound generation start instruction (at key-on) and changes with time and attenuates and disappears from a musical sound generation end instruction (at key-off), that is, a so-called envelope signal, Also, a touch signal of performance by a keyboard can be used. Alternatively, a low-frequency signal used for modulation such as tremolo or vibrato may be used as a tone control signal. Further, time division processing may be performed to enable multiple sound generation.
In addition, there are controls that directly operate parameters,
The parameter may be key-scaled. In the above embodiment, the circuit is configured by a digital circuit. However, the circuit may be configured by an analog circuit.
Active filters can be used. Further, in such a case, the characteristics of the analog circuit elements themselves such as transistors and diodes are used as a table configured as a ROM or a non-linear conversion circuit, and the arithmetic circuits such as adders and multipliers are also used for analog arithmetic operations using an operational amplifier or the like. It is preferable to use a delay circuit such as a BBD or an LCR as the delay means. The method of changing the pitch is not limited to the method of changing the entire length of the tubular body as in the above embodiment, but may be a method of simulating a tone hole using a three-port junction. Also, to perform fine control of the pitch,
The number of delay stages in a shift register of a specific stage may be adjustable, and in that case, adjustment may be performed by linear interpolation. Although the tube is simulated in the above embodiment, a new sound may be created. Further, the present invention is not limited to wind instruments and can be used as a tubular sound effect device.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an electronic musical instrument according to one embodiment of the present invention, FIG. 2 is an external view of a tube-type operator, FIG. 3 is a block diagram of an operation detection unit, and FIGS. FIG. 6 is a specific block diagram of a junction, FIG. 7 is a characteristic diagram of a low-pass filter, FIG.
FIG. 9 is a schematic diagram of a junction for a frequency component lower than the cutoff frequency. FIG. 9 is a schematic diagram of a junction for a frequency component higher than the cutoff frequency.
FIG. 10 is a spectrum diagram showing frequency components of the circulating signal by the first circuit, FIG. 11 is a spectrum diagram showing frequency components of the circulating signal by the second circuit, and FIG. 12 is a characteristic diagram of the low-pass filter. FIG. 13 is a spectrum diagram showing frequency components of a circulating signal obtained in this embodiment. 430 …… Tube simulation unit, 431… Ladder circuit, SR1
(1a, 1b), SR2 (2a, 2b) ... shift register, J ... junction, 431J2 ... filter.

Claims (1)

(57) [Claims] 1. First and second signal transmission means comprising a forward path and a return path for transmitting a waveform signal and having delay means interposed in at least one of the forward path and the return path; and the first and second signal transmission means. Connected between the signal transmission means of the first signal transmission means and the return signal of the first signal transmission means and the outward path of the second signal transmission means. And connection means for transmitting a signal from the return path of the second signal transmission means to the outward path of the second signal transmission means and the return path of the first signal transmission means, respectively. A waveform signal output device for outputting a waveform signal having the signal from the outgoing path of the first signal transmitting means to the return path of the first signal transmitting means and the outward path of the second signal transmitting means in the connecting means. Frequency characteristics of signal transmission Filters are provided which are different from each other and have different frequency characteristics of each signal transmission from the return path of the second signal transmission means to the outward path of the second signal transmission means and the return path of the first signal transmission means. A waveform signal output device characterized by the above-mentioned.