JP3413846B2 - Music synthesizer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a delay feedback type tone synthesizer for synthesizing a tone by exciting oscillation in a loop circuit including delay means, and more particularly to a natural musical instrument. The present invention relates to a musical tone synthesizer capable of synthesizing musical tones of rich timbres as seen in the above. 2. Description of the Related Art Japanese Patent Application Laid-Open No. 63-40199 discloses that a sounding mechanism of a wind instrument or the like is electrically simulated by using a loop circuit including delay means. In this publication, a signal corresponding to breath pressure is input to the loop circuit as an excitation signal for exciting a tone signal. [0003] However, in the above-mentioned prior art, basically, only a single-tone pronunciation is simulated, and a special configuration for making a double-tone pronunciation is not mentioned at all. Not. For example, in the case of a piano as a compound music instrument, the vibration of a string is transmitted to other strings through a hammer mechanism or the like. In addition, the organ and the accordion also have a sound generator connected via an air reservoir. Therefore, in the case of a polyphonic instrument, the effects of pressure changes and air spills associated with oscillation are commonly related to all sounding sections, and for this reason the polyphonic instrument has a different richness than the monophonic instrument. The musical expression is formed. [0004] The invention described in claim 1 of the present application has been made in view of the above-mentioned drawbacks of the prior art. Even when a tone synthesizer is constructed as a multiple tone generation, another richness different from that of a single tone generation is provided. It is an object of the present invention to provide a musical sound synthesizing device capable of generating various musical sounds. According to a first aspect of the present invention, a plurality of loop circuits having a delay time corresponding to a pitch of a musical tone to be generated and a plurality of loop circuits common to the plurality of loop circuits are provided. A common signal processing means for generating and processing an excitation signal for exciting a tone signal, and inputting the processed signal to each loop circuit, and being excited by at least one of the plurality of loop circuits. Introduction means for delaying a tone signal by a predetermined time and introducing the signal to the common signal processing means, wherein the common signal processing means performs the signal processing including the tone signal introduced by the introduction means. I do. According to the first aspect of the present invention, a signal excited in at least one of the plurality of loop circuits affects a common excitation signal for the plurality of loop circuits. FIG. 2 is a block diagram showing the configuration of an electronic musical instrument including a musical sound synthesizer according to the present invention. Reference numeral 1 denotes a keyboard, which includes a key-on signal indicating a key pressed and a key-off signal indicating a key released based on a key operation by a player, a key code signal indicating a pitch of a key depressed or released, and a key depressing operation. MIDI (Musical Ins.)
Output as a digital signal (trument Digital Interface). Reference numeral 2 denotes a control unit.
Receiving the IDI signal, it creates tone synthesis parameters NF, DL, FC for sending to the tone synthesizer 5 described later. The contents of these parameters will be described later. Reference numeral 4 denotes a pedal, which is used by a player to perform a stepping / stepping up operation. The pedal 4 has a built-in potentiometer, and outputs a signal corresponding to the turning angle of the pedal 4 in response to the stepping-in / step-up operation.
The control section 2 converts the output signal from the pedal 4 into a digital signal PD in a format corresponding to the processing of the tone synthesis section 5 and outputs the digital signal PD to the tone synthesis section 5. Reference numeral 3 denotes a channel assigner for selectively giving parameters NF, DL, and FC given by the control unit 2 to a plurality of tone generation channels in the tone synthesis unit 5. The selected channel number CH is output to the musical sound synthesizing unit 5 together with the respective parameters. For how to select the pronunciation channel,
Since many proposals have been made, such as a first-come-first-served method and a last-come-first-served method, detailed descriptions thereof are omitted here. The tone synthesizer 5 includes parameters PD, NF,
DL, FC and the channel number CH are received, and a tone signal is digitally synthesized using the parameters PD, NF, DL, and FC on the sounding channel specified by the channel number CH and output. Reference numeral 6 denotes a D / A converter, which is a tone synthesizer 5
Is converted to an analog signal and output. Reference numeral 7 denotes a sound system, which amplifies an output signal from the D / A converter 6 to a speaker driving level and then emits the sound as a musical sound from the speaker. FIG. 1 is a block diagram showing the internal structure of the musical tone synthesizer 5. 11 is a signal PD from the control unit 2
Is a digital differentiator, but because of digital processing,
It consists of a difference circuit with an adder having a delay of one sample time and a negative input. Reference numeral 12 denotes a comparison unit that compares the output signal of the differentiator 11 with the signal level “0” and outputs the larger one. That is, only the portion where the output level of the differentiator 11 is positive is passed, and the negative portion is output as the signal level “0”. Reference numeral 13 denotes an accumulator, which includes a delay unit with one sample time delay and an adder. 1
A multiplier 4 multiplies an output signal of the accumulator 13 by a predetermined constant. In the above-described configuration, when a signal PD corresponding to the angle of the pedal is input, the PD is differentiated by the differentiator 11 and only the positive portion is taken out by the comparator 12, so that the pedal 4 is depressed. Only when the signal is the accumulator 1
3 and there is no response during the step-up operation. In this case, since the output of the differentiator 11 has a signal level proportional to the speed of the stepping operation, the output of the comparison unit 12 also becomes a larger positive signal as the speed of the stepping operation increases. The output of the comparison section 12 is accumulated by an accumulation section 13. In other words, if the pedal 4 is compared to an air-feed pedal of a foot-operated organ, it corresponds to an operation in which air is sent to the tank by the air-feed pedal and gradually accumulates. The multiplier 14 performs processing corresponding to dividing the amount of air in the tank by the volume of the tank. That is, the multiplier 14 converts the air amount into pressure based on the gas state equation and outputs the converted pressure. The negative input of the adder in the accumulator 13 will be described later. The signal converted into the pressure signal by the multiplier 14 is sent to the gate 15 at the input of each sounding channel in common to each channel. Each sound channel CH1
Since all CHn have the same configuration, only the CH1 is given a number, and the description of the other sounding channels is omitted. In each sounding channel, a gate 15
Is normally closed, and is opened only while the channel is selected as a sounding channel from the channel assigner 3 and turned on by the key-on / key-off signal NF.
A loop circuit is configured by the adder 16, the non-linear converter 17, the delay unit 18, and the filter 19. When the pressure signal is input to the loop circuit via the gate 15 and the adder 16, the signal is nonlinearly converted by the nonlinear conversion unit 17 with characteristics as shown in FIG. The conversion characteristics of this non-linear conversion are similar to the non-linear conversion characteristics of the air input of the air column in the organ. The signal nonlinearly converted by the nonlinear converter 17 is delayed by the delay unit 18 by a time corresponding to the pitch. Here, in the configuration of this embodiment, since a negative feedback loop is used as described later, one cycle is obtained with a delay time of two rounds of the loop circuit. Therefore, the delay time of the delay unit 18 is set so as to be 1/2 of the desired pitch frequency, including the phase delay time of the filter 19 described later. This delay time is based on the key code of the key operated in the keyboard 1,
Parameter D representing delay time in control unit 2
It is calculated and output as L, and applied to the delay unit 18 of the sounding channel selected by the channel assigner 3. The signal delayed by the delay unit 18 is given a frequency attenuation characteristic by a filter 19. Filter 1
9 corresponds to the attenuation characteristic of the sound wave received at the end of the air column of the organ, but here, in order to be able to adjust the tone,
The characteristics can be changed by the filter coefficient FC. The filter coefficient FC is set in the control unit 2 in accordance with the initial touch information from the keyboard, and is provided to the filter 19 of the sound channel specified by the channel number CH. The signal given the frequency attenuation characteristic by the filter 19 is input to the negative input of the adder 16 and the gate 15
Is added to the non-linear conversion section 17 again, and thereafter circulates in the loop circuit, and a periodic waveform signal is excited in the loop circuit. In this way, the waveform signals generated from each sounding channel are output from a predetermined position of the loop (in FIG. 1, immediately after the nonlinear conversion section), and are added by the adder 20. Thereafter, the signal is output to the D / A converter 6 via the high-pass filter 22. The high-pass filter 22 is for removing a DC component from the excited waveform signal. Since the non-linear converter 17 converts all the input signals to positive, a DC component is generated. Since the DC signal may damage the circuit, the high-pass filter 22 is used so as not to damage subsequent circuits (an amplifier and a speaker in the sound system 7). On the other hand, as an example of an organ simulation, since a pressure signal propagates back and forth in a loop circuit to synthesize a tone signal as a pressure wave, an adder 2 is used.
An output of zero is the sum of the oscillating pressures in the plurality of organ columns. The sum of the oscillating pressures is sent to the negative input of the adder in the accumulator 13 via the delay unit 23 and the multiplier 21. The multiplier 21 multiplies the sum of the oscillating pressures by the volume of the air column. In other words, this corresponds to an operation of converting the outflow air amount and subtracting it from the tank according to the gas state equation. The delay time set in the delay unit 23 corresponds to the time lag between the flow of air and the transmission of the pressure change. The delay time differs depending on the viscosity, elasticity, temperature, etc. of the air. Is set. This changes the amount of air in the tank from the air tank in accordance with the amount of air flowing out and in response to the vibration, so that the pressure as the excitation signal corresponds to the excited periodic waveform. Will change slightly. In the above embodiment, the gate 15
Is opened and closed, but may be smoothly changed using an envelope generator. Also,
Instead of the multiplier 14, a signal converter representing a van der Waals equation of state may be used to treat air as something closer to a real gas than to treat it as an ideal gas. Further, the comparing section 12 may use an absolute value circuit. In this case, a positive level output signal is obtained even when the pedal 4 is depressed. Further, the operation element is not limited to the pedal, but may be a manual operation element or an operation detector using an acceleration sensor. Although the above embodiment has been described as an organ, details may be modified so as to be equivalent to a piano or accordion. As described above, according to the first aspect of the present invention, the signal excited in at least one of the plurality of loop circuits becomes a common excitation signal for the plurality of loop circuits. As a result, complex and rich musical tones are synthesized in the same manner as a natural musical instrument that produces multiple tones.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall block diagram of an embodiment of the present application. FIG. 2 is a block diagram of a musical sound synthesizer according to the embodiment of the present application. FIG. 3 is a conversion characteristic diagram of the nonlinear converter according to the embodiment of the present application. [Description of Signs] 13: Accumulator 16: Adder 21: Multiplier 31: Loop circuit 32: Loop circuit 33: Loop circuit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G06F 17/10 G10H 1/00-7/00 H03B 28/00

Claims (1)

(57) [Claim 1] A plurality of loop circuits having a delay time corresponding to a pitch of a musical tone to be produced, and a plurality of loop circuits provided in common with the plurality of loop circuits, Common signal processing means for generating and processing an excitation signal for excitation, and inputting the processed signal to each loop circuit; delaying a tone signal excited in at least one of the plurality of loop circuits by a predetermined time; And an introduction means for introducing the signal to the common signal processing means, wherein the common signal processing means performs the signal processing including the tone signal introduced by the introduction means.