JP2591001B2 - Electronic string instrument - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic stringed instrument such as an electronic guitar, and more particularly, to detecting that the level of an input waveform signal has abruptly attenuated and turning off the musical tone (relative off). The present invention relates to an electronic stringed musical instrument that can perform

[Conventional technology]

Conventionally, a pitch (fundamental frequency) is extracted from a waveform signal generated by a playing operation of a natural musical instrument, and a sound source device constituted by an electronic circuit is controlled to artificially obtain a sound such as a musical sound. Various electronic musical instruments have been developed.

As this kind of electronic musical instrument, there is an electronic guitar or a guitar synthesizer, and the present applicant has already proposed such an musical instrument having the above-described relaive-off function (Japanese Patent Application No. 62-76453). No., Japanese Patent Application No. 62-258673, etc.) In this relative-off process, the sound source device is instructed to mute the sound by releasing the finger on which the fret operation is performed. Such an instruction is executed by detecting that the level has rapidly changed in attenuation.

However, according to the above proposal, regardless of the pitch detected based on the pitch extraction, the above-described relativ-off processing is performed under the same conditions. When the finger is released from the state in which the center of the long is pressed with the finger (that is, the pitch specified one octave above the open string pitch), the vibration is hard to stop,
As compared with other positions, it becomes more difficult to detect the above-mentioned attenuation change, and there arises a problem that the player cannot give an off instruction intended.

If such a gradual decay is also detected and sound is stopped, even when performing a grit sand or slur performance operation, it is regarded as a relative off,
The problem of note-off will occur.

[Object of the invention]

The present invention has been made in view of the above circumstances, and is capable of surely instructing the sound source means to mute the sound even when a mute operation is performed at a pitch one octave higher than the open string pitch in which string vibration continues for a long time. The purpose is to submit electronic stringed instruments.

[Gist of the invention]

That is, in order to achieve the above object, the present invention provides an amplitude detecting means for detecting an amplitude of a string vibration, a pitch detecting means for detecting a pitch of the string vibration, and a sound corresponding to the pitch detected by the pitch detecting means. Tone generating means for instructing generation of a high tone, determining means for determining whether or not the pitch detected by the pitch detecting means is substantially equal to a pitch one octave above the open string; and If the determining means determines that the pitch of the vibrating string is substantially equal to the pitch one octave higher than the open string during the generation of the musical tone by the instruction of the generating instruction means, the amplitude detecting means detects the pitch. When the amplitude decay rate is equal to or greater than a first predetermined value, the sounding tone being generated is instructed to be muted, and the pitch of the vibrating string substantially matches the pitch one octave above the open string. Pi And when the attenuation rate of the amplitude detected by the amplitude detection means is equal to or greater than a second predetermined value greater than a first predetermined value, the sound generation instructing means for instructing the sound generation to be silenced. The point is to have.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Here, a case where the present invention is applied to an electronic guitar will be described as an example. The present invention is not limited to this, and can be similarly applied to other types of electronic musical instruments.

FIG. 1 is a block diagram showing the entire circuit. A pitch extracting analog circuit PA is provided on each of six strings stretched on, for example, an electronic guitar body (not shown), and converts the vibration of the strings into an electric signal. And a zero-cross signal and a waveform signal Z from the output from this pickup.
i, Wi (i = 1 to 6) and conversion means for converting these signals into a time-division serial zero-cross signal ZCR and a digital output (time-division waveform signal) D1, for example, an analog-digital converter A described later / D.

The pitch extraction digital circuit PD constitutes amplitude detection means and pitch detection means in the present embodiment,
As shown in Fig. 2, peak detection circuit PEDT, time constant conversion control circuit TCC, peak value acquisition circuit PVS, zero cross time acquisition circuit
ZTS, the maximum peak point or the minimum peak point is detected based on the serial zero cross signal ZCR from the pitch extraction analog circuit PA and the digital output D1, and MAXI, MINI
(I = 1 to 6), and outputs an interrupt (interrupt) signal INT to the microcomputer MCP at the passage of the zero cross point, more precisely, at the zero cross point immediately after the maximum peak point and the minimum peak point. It outputs time information and peak value information, for example, MAX and MIN, and instantaneous values of input waveform signals to the microcomputer MCP. Note that a circuit is provided inside the peak detection circuit PEDT for holding while subtracting a past peak value.

The time constant conversion control circuit TCC changes the decay rate of the peak hold circuit of the peak detection circuit PEDT. When a peak cannot be detected even after a lapse of, for example, one cycle of the waveform, the decay rate is rapidly reduced. To do it. Specifically, in the initial state, the waveform rapidly attenuates after the maximum sound period elapses in order to quickly detect the vibration of the waveform, and does not pick up harmonics when the string vibration is detected. Similarly, rapid decay is performed over time, and after the vibration period of the string is extracted, rapid decay is performed at that period.

The setting of the cycle information for the time constant conversion control circuit TCC is performed by the microcomputer MCP. Then, each string-independent counter in the time constant conversion control circuit TCC is compared with the set period information, and the time constant change signal is sent to the peak detection circuit PEDT after the period time elapses.

The peak value capturing circuit PVS in FIG. 2 performs a demultiplexing process on the waveform signal (digital output) D1 transmitted in a time-division manner as described above into a peak value for each string, and a peak detection circuit PEDT MAXI, MINI peak signals from
The peak value is held in accordance with (I = 1 to 6). Then, the microcomputer MCP outputs the maximum peak value or the minimum peak value of the string accessed through the address decoder DCD to the microcomputer bus. The peak value capturing circuit PVS can also output the instantaneous value of the vibration of each string.

The zero cross time acquisition circuit ZTS latches the output of the time base counter common to each string at the zero cross point of each string (strictly speaking, the zero cross point immediately after passing the maximum peak point and the minimum peak point). Then, in response to a request from the microcomputer MCP, the latched time information is transmitted to the microcomputer bus.

Further, a timing signal for processing operations of the respective circuits shown in FIGS. 1 and 2 is output from the timing generator TG shown in FIG.

The microcomputer MCP has a memory, for example, a ROM and a RAM, and also has a timer T, and controls a signal to be supplied to the sound source generator SOB. Sound source generator SOB
Is sound source SS, digital-analog converter D / A, and amplifier AMP
And a speaker SP, and emits a musical tone having a pitch corresponding to a pitch instruction signal for changing the frequency from note-on (sound generation) to note-off (silence) from the microcomputer MCP.
Note that an interface (Musical Instrument Digit) is provided between the input side of the sound source SS and the data bus BUS of the microcomputer MCP.
al Interface) MIDI is provided. Of course, when the sound source SS is provided on the guitar main body, another interface may be used. When an address read signal AR from the microcomputer MCP is input, the address decoder DCD outputs a string number read signal RDI and a time read signal RDj (j = 1 to 6).
The peak value of MAX and MIN and the instantaneous value read signal RDAI (I = 1 to 18) at that time are pitch-extracted digital circuit PD
Output to

Hereinafter, the operation of the microcomputer MCP will be described with reference to the drawings showing flow charts and waveforms. First, reference numerals in the drawings will be described.

AD: input peak value (instantaneous value) directly reading the input waveform of the pitch extraction digital circuit PD by the instantaneous value read signals RDA13 to RDA18 in FIG. 1 AMP (0, 1): positive or negative previous (old) wave High value AMRL1 ... Relative (rel) stored in the amplitude register
ative) The previous amplitude value for the off check. Here, the "relative off" corresponds to a silencing process when the fret operation is stopped and the sound is shifted to an open string by canceling the sound based on a sudden decrease in the peak value.

AMRL2... The amplitude value of the last two times for the re-laive-off stored in the amplitude register, to which the value of AMRLI is input.

ANE… Constant 1/40 or 1 for relative off-jazz
Remember / 20.

CHTIM: a cycle corresponding to the highest tone fret (22 fret) CHTIO: a cycle corresponding to the open string fret CHTRR: a time constant conversion register provided in the time constant conversion control circuit TCC (FIG. 2). .

DUB: A flag indicating that the waveform has continuously come in the same direction FOFR: Relative off counter HFOP: A constant indicating the period corresponding to the scale one octave above the open string HNC: Waveform number counter MT: Pitch extraction from this Flag (positive = 1,
(Negative = 0) NCHLV: Notch level (constant) OFTIM: Off time (corresponding to, for example, the open string cycle of the string) OFPT: Normal off-check start flag ONF: Note-on flag RIV: Processing in step (STEP 4) described later Flag for switching the route ROFCT: A constant that determines the number of checks for the rela- tive-off STEP: Registers (1 to 5) that specify the flow operation of the microcomputer MCP TF: Previous zero-crossing time data that has become valid TFN (0, 1) … Previous zero-cross time data immediately after the positive or negative peak value TFR… Time storage register THLIM… Frequency upper limit (constant) TLLIM… Frequency lower limit (constant) TP (0,1)… Positive or negative previous cycle data TRLAB ( 0, 1)… positive or negative absolute trigger level (note-on threshold) TRLRL… relativ-on (start of re-generation) threshold TRLRS… resonance elimination threshold TTL IM: Lower frequency limit at the time of trigger TTP: Period data extracted last time TTR: Period register TTU: Constant (product of 17/32 and current period information tt) TTW: Constant (product of 31/16 and current period information tt) VEL: Information that determines the speed (velocity) and is determined by the maximum peak value of the waveform at the start of sound generation.

X: Flag indicating an abnormal or normal state b: Current positive / negative flag stored in working register B (1 at the next zero point after the positive peak, 0 at the next zero point after the negative peak) c: Working register register The current peak value (peak value) stored in C e... The pre-second peak value (peak value) stored in the working register E h... The periodic data extracted before and after the second time stored in the working register H t. The current zero-crossing time stored in T0 tt... The current cycle information described in the working register TOTO FIG. 3 is an interrupt routine showing a process when an interrupt is applied to the microcomputer MCP. The microcomputer MCP sends a string number read signal RDI to the zero-cross time acquisition circuit ZTS via the address decoder DCD.
To read the string number specifying the string that gave the interrupt. Then, the time information corresponding to the string number, that is, the zero-cross time information, is supplied to the zero-cross time fetch circuit ZTS by giving any one of the time read signals RD1 to RD6. This is defined as t. Thereafter, at I2, the peak value reading signal RDAI (I
= 1 to 12) and read the peak value. This is assumed to be c.

In the following I3, information b indicating whether the peak value is a positive or negative peak is obtained from the zero-crossing time acquisition circuit ZTS. Then, at I4, the values of t, c and b obtained in this way are set in buffer registers TO, C and B in the microcomputer MCP. In this buffer, every time interrupt processing is performed, such time information, peak value information, and information indicating the type of peak are written as one set, and the main routine performs processing on the information for each string. You.

FIG. 4 is a flowchart showing a main routine. When the power is turned on, various registers and flags are initialized in M1, and the register STEP is set to 0. At M2, it is determined whether or not the above-mentioned buffer is empty. If no (hereinafter, referred to as N), the process proceeds to M3, and the contents of the registers B, C, and TO are read from the buffer. Thereby, in M4, some registers STEP are determined,
STEP0 for M5, STEP1 for M6, STEP2 for M7, STEP for M8
3. In M9, the processing of STEP4 is sequentially performed.

If the buffer is empty at M2, that is, if the answer is yes (hereinafter, referred to as Y), the process sequentially proceeds to M10 to M16, where the normal note-off algorithm processing is performed. This no-off algorithm is an algorithm in which note-off is performed when a state below the off level (OFF) continues for a predetermined off-time period. In M10, it is determined whether or not STEP = 0, and in the case of N, the process proceeds to M11. In M11D, the input peak value AD at that time is directly read. This can be achieved by applying any one of the peak value reading signals RDA13 to RDA18 to the peak value capturing circuit PVS. Then, it is determined whether or not this value AD is the input peak value AD off level.
Proceed to M12. In M12, it is determined whether or not the previous input peak value AD off level. In the case of Y, the process proceeds to M13, where it is determined whether or not the value of the timer T is OFF time OFTIM (for example, a constant of the open string period of the strings). You. In the case of Y,
In M14, 0 is written in the register STEP. In M15, it is determined whether or not the note is on. In the case of Y, the note-off process is performed in M16, and the process returns to M on the input side of M2. In the case of N in M12, the process proceeds to M17, the microcomputer MCP internal timer T is started, and the process returns to the entry side M of M2. In case of Y in M10, and M11, M1
3. In the case of N in M15, all return to M on the entry side of M12.

Thus, when the level of the waveform input is attenuated,
When the input peak value AD equal to or less than the off level continues for a time corresponding to the off time OFTIM, the microcomputer MCP sends a note-off instruction to the sound source SS. In step M15, the determination of Y is made in a normal state. However, the register STEP may take a value other than 0 even when the generation of a musical tone is not instructed by the processing described later. Yes (for example, due to noise input) In such a case, M14, M15
By returning to M2 after the processing of, the initial setting is performed.

Although FIG. 4 shows only the processing for one string, the processing shown in this figure is multiplexed six times corresponding to the number of strings, and the microcomputer MCP executes the processing. Of course, a plurality of processors may be provided, and the same processing may be executed separately and independently.

Next, details of each routine for branching and performing corresponding processing in M4 will be described.

FIG. 5 shows step 0 (STEP 0) shown as M5 in FIG.
0), the absolute trigger level (note-on threshold) TRLAB (b) <the present peak value c is determined at S01. If Y, the process proceeds to S02 to check the resonance elimination. You. It should be noted that the trigger level checks the respective peaks of positive and negative polarities. These TRLAB (0) and TRLAB (1)
Appropriate values will be determined by experiments and the like. In an ideal system, TRLAB (0) and TRLAB (1) may be the same. In S02, the resonance removal threshold value TRLRS <[current peak value c
−previous peak value AMP (b)], that is, whether the difference between the current peak value and the previous peak value is equal to or greater than a predetermined value.

When picking one string causes another string to resonate, the vibration level of the other string gradually increases, and as a result, the change in the peak value between the previous time and the current time is very small. The difference is the resonance rejection threshold
Never exceed TRLRS. However, in normal picking, the waveform suddenly rises (or falls), and the difference between the peaks exceeds the resonance removal threshold value TLRRS.

If it is determined in S02 that it is not the case of Y, that is, the case of resonance, the following processing is performed in S03. That is, the current positive / negative flag b is written into the flag MT, 1 is written into the register STEP, and the current zero-cross time t is set as the previous zero-cross time data TFN (b). Then, in S04, other flags are initialized, and the process proceeds to S05. In S05, the current peak value c is set as the previous peak value AMP (b), and thereafter, the process returns to the main flow of FIG.

In FIG. 5, A is a relativity on (re-sound start).
The entry of S06 from the flow of STEP 4 described later
Hey jump. Then, in S06, the musical tone output so far is deleted once, and the process proceeds to S03 to start re-sounding. The process for starting re-sound generation is the same as that for starting normal sound generation, and will be described in detail below.

Then, in the case of N in S01 and the case of N in S02 (when the current peak value c-the previous peak value AMP (b) is not equal to or more than the predetermined value), the process proceeds to S05. Accordingly, the process for starting sound generation does not proceed.

In STEP 0 described above (between STEP 0 and 1 in FIG. 11), the contents of the B register (b = 1) are written in the flag MT, and the contents (t) of the register TO are set to the previous zero-crossing time data TFN.
(1) is written, and the peak value (c) of the register C is written to the previous peak value AMP (1).

FIG. 6 shows the details of the flowchart of STEP 1 shown as M6 in FIG. 4. In S11, it is determined whether or not the content (b) of the register B and the flag MT do not match.
In the case of, the process proceeds to S12. In S12, it is determined whether or not the absolute trigger level (note-on threshold) TRLAB (b) <the current peak value c. If Y, the process proceeds to S13. In the case of Y in S12, 2 is set in the register STEP, and in S14, the register TO
(T) is replaced with the previous zero-cross time data TFN (b)
Then, in S15, the current peak value c is set to the previous peak value AMP (b). In S11, in the case of N, that is, when the input waveform signal comes in the same direction, the process proceeds to S16, and it is determined whether or not the current peak value c> the previous peak value AMP (b). If it is larger than the peak value AMP (b), the process proceeds to S14. Meanwhile, S12
In the case of N, the process proceeds to S15, whereby only the peak value is updated. In S16, if N, or at the end of the processing in S15, the process returns to the main flow (FIG. 4).

In STEP 1 described above (between STEP 1 and STEP 2 in FIG. 11), since the current positive / negative flag b (= 0) and the flag MT = 1 do not match, the current zero cross time t is set to the previous zero cross time data TFN (0 ), And the current peak value c is written as the previous peak value AMP (0).

FIG. 7 shows the details of the flow chart of STEP 2 shown as M7 in FIG. 4. In S20, it is determined whether or not the current positive / negative flag b = flag MT, that is, whether or not the same zero-cross point as the direction of STEP0 has arrived. And in the case of Y, S2
Proceed to 1. In S21, the open chord cycle CHTIO is set in the register CHTRR in the time constant conversion control circuit TCC of FIG. 2, and the flow advances to S22. In S22, the current peak value c> (7/8) x the previous peak value
It is checked whether it is AMP (b), that is, whether the peak value is substantially the same between the previous time and this time, and in the case of Y, that is, in the case of beautiful natural attenuation, the process proceeds to S23, the flag DUB is set to 0, and the process proceeds to S24. move on. In S24, a cycle calculation is performed, and the current zero-cross time t−the previous zero-cross time data TFN is calculated.
(B) is input to the previous cycle data TP (b), and the current zero cross time t is input as the previous zero cross time data TFN (b). TP (b) in S24 is used as a note-on (1.5 wave) condition in STEP3. At S24, the register STEP is set to 3. Further, the present peak value c, the previous peak value AMP (0), and the previous peak value AMP
The largest value among (1) is registered as velocity VEL. Also, the current peak value c is written to the previous peak value AMP (b).

In the case of N in S20, the process proceeds to S25, where the flag DUB, that is, the flag indicating that an input waveform in the same direction has arrived, is set to 1, and the process proceeds to S26. In S26, it is determined whether or not the present peak value c> the previous peak value AMP (b). If Y, the process proceeds to S29. In S29, the previous peak value AMP (b) is rewritten to the current peak value c, and the previous zero-cross time data TFN (b) is rewritten to the content t of the register T. In S22, in the case of N, the process proceeds to S27, and a check is performed to determine whether or not the flag DUB = 1, that is, when STEP2 was executed last time, whether or not a tab was found.
Proceed to 8. In S28, the flag DUB is set to 0. In this case, the process proceeds to S29 and returns to the main routine. After the processing in S24 and also in the case of N in S26, the process similarly returns to the main routine (RET).

In the above-mentioned STEP 2 (between STEP 2 and STEP 3 in FIG. 11), the flag MT = 1 is rewritten as the positive / negative flag b, the 0-flet cycle, that is, the open string cycle CHTIO is rewritten in the register CHTRR, and the flag DUB is set to 0. Is set, and the cycle calculation of t−TFN (1) → TP (1) is performed.
TFN (1) is rewritten and the current crest value c and the previous crest value A
The largest value of MP (0) and the previous peak value AMP (1) is set as velocity VEL, and the previous peak value AMP (1) is set as the current peak value c.

FIG. 11 shows an example in which there is an ideal waveform input. A case in which DUB = 1 will be described below. FIG. 8 is a diagram for explaining the operation of STEP 2 in such a case. FIG. 8 (A) shows a case where one wave is skipped and a peak is detected. And note-on does not occur when the input waveform is a dotted line. This is due to the difference between Y and N in S26. Also, the reason why it does not easily shift from STEP 2 to STEP 3 is that even if b = MT is satisfied in S20, c> (7/8) × AMP in S22.
As long as (b) is determined to be N and this is not Y, STEP
2 is executed repeatedly. (B) shows a case where an overtone lower than an octave is detected. In this case, when checking that C> (7/8) × AMP (b), Y becomes Y and S2
After 3, go to S24 and move to STEP3.

FIG. 9 is a flowchart of STEP 3 shown as M8 in FIG. 4. In S30, it is determined whether or not the flag MT ≠ the current positive / negative flag b. If the flag is normal, that is, if Y, the process proceeds to S31. In S31, if (1/8) c <AMP (b), X is set to 0, and if not, X = 1 is set, and the process proceeds to S32. In S32, the previous peak value AMP (b) is rewritten as the current peak value c.

Then, in S33, if the current peak value c is larger than the VEL obtained in STEP2, the current peak value c is input as the velocity VEL. If vice versa, this velocity VEL will not change. Next, the flag MT is rewritten to the current positive / negative flag b, whereby the pitch change side is reversed. This means that the meaning of the flag MT is different from STEP 4 described later, and means a pitch change side. Then, in S34, [t-TFN (b) → TP
(B)]. The current zero-cross time t is used as the previous zero-cross time data TFN.
(B) is rewritten.

Next, in S35, it is determined whether or not X = 0, and in the case of Y, the flow proceeds to S36, and whether or not the frequency upper limit THLIM <the previous cycle data TP (b), that is, the pitch extraction upper limit check is performed. If the period is longer than the period of the highest sound, it is Y because it is within the allowable range, and the process proceeds to S37. In S37, whether the lower limit of the frequency at the time of triggering is TTLIM> the previous cycle data TP (b), that is, a pitch extraction lower limit check is performed, and if a cycle shorter than the cycle of the lowest tone is within the allowable range, the judgment of Y is made. And proceed to S38. The lower limit of the pitch extraction of S37 is different from the constant of the lower limit of the pitch extraction of STEP4 described later.

Specifically, the upper frequency limit THLIM corresponds to a pitch period two to three semitones above the highest note fret, and the lower frequency limit TTLIM at the time of triggering corresponds to a pitch period five semitones below the open string fret of the open string. Shall be equivalent.

In S38, the previous cycle data TP (b) is set as the previously extracted cycle data TTP, that is, the pitch extracted on the pitch extraction side is saved (this is used in STEP 4 described later), and the flow proceeds to S39. In S39, whether or not the previous cycle data is TP (b) ≒ TP (), that is, a 1.5-wave pitch extraction check which is a check of the cycle between zero-cross points having different polarities is performed. In the case of Y, the next step is S301. The following processing is performed. That is, the time storage register TFR is rewritten as the previous zero-cross time data TFN (), the current zero-cross time t is set using the previous zero-cross time data as TF, and the waveform number counter HNC is cleared. This counter HNC is used in STEP4 described later.
Used in The register STEP is set to 4, the note-on flag ONF is set to 2 (sound generation state), and the constant T
TU is set to 0 or (MIN) and constant TTW is the highest MA
Set to X. These are all used in STEP 4 described later. Also, the previous peak value register AMRL1 for the relaive-off is cleared. And the last S
In 302, note-on processing is performed at a pitch corresponding to the previous cycle data TP (b) and a volume corresponding to the velocity VEL. That is, the microcomputer MCP functions as a musical sound generation instructing unit in this embodiment, and instructs the sound source SS to start sounding.

Next, in S310, the microcomputer MCP functions as the determination means in the present embodiment, and the extraction cycle TP (b) is set to a cycle HFOP corresponding to a pitch one octave above the open string pitch of the string.
It is determined whether or not they substantially match. That is, if the difference between the constant HFOP and the obtained period TP (b) is within 5% of HFOP, it is regarded as a pitch one octave higher than the open string pitch, and the register ANE is sent to the register ANE as the first predetermined value. 1/40 is input in S311. If the pitch is other than that, 1/20 which is a second predetermined value larger than the first predetermined value (1/40) is input to the register ANE in S312.
Enter in. The value stored in ANE is 1/40
Although they are set to (first predetermined value) or 1/20 (second predetermined value), these may be set to optimal values by experiments and the like.

In S30, in the case of N (in the case of zero-cross point detection in the same direction), the process proceeds to S303, and the previous peak value AMP (b) <
It is determined whether or not this time is the peak value c, and in the case of Y, the process proceeds to S304. In S304, the current peak value c is the previous peak value AMP (b)
And the larger of the velocity VEL and the value c of the register C is set to the velocity VEL. N in any of S303, S35, S36, S37, S39
In this case, return to the main routine (RET.).

FIG. 17 is a diagram showing a specific example of a case where X = 1, that is, an abnormality, in S31, wherein 1 / 8b ₁ <b ₀ and 1 / 8a ₂
<Both in Jiyatsuji when the a ₁ does not satisfy the condition, the X = 1.

That is, the peaks (a ₀ ,
b ₀ and a ₁ ) are caused by noise. If the cycle of these noises is detected and the start of sound generation is instructed, a completely strange sound is generated. Therefore, in S31, it is detected that the peak value has changed greatly, X = 1, and N is determined in S35. Then, in S31, it is instructed to start sound generation after it is detected that the waveform changes normally.

In the case of FIG. 17, note-on occurs when TP (b) ≒ TP () is detected.

In STEP 3 described above (between STEP 3 and 4 in FIG. 11), the MT
= 1 ≠ b, AMP (0) ← c, max [VEL, c (whichever is greater)] → VEL, MT ← b = 0, TP (0) ← [t−T
FN (0)], TFN (0) ← t, TTP ← TP (0), TFR ← TFN
(1), TF ← t, HNC ← 0, ONF ← 2, TTU ← 0 (MIN),
TTW ← MAX, AMRL1 ← 0, note-on condition TP (o) ≒ TP
The processing of (1) and ANE ← 1/20 or 1/40 are performed. Then, in response to the appropriate waveform input, in STEP 3, generation of a musical tone having a pitch according to the extracted pitch is started. As can be seen from FIG. 11, a sound generation instruction is issued to the sound source SS about 1.5 cycles after the start of the cycle detection. Of course, if the various conditions are not satisfied, further delays are as described above.

FIG. 10 is a flowchart of STEP 4 shown as M9 in FIG. 4. In this case, there is a route for only extracting the pitch and a route for actually changing the pitch. First,
The routes shown in S40, S41, S42, and S63 to S67 will be described. In S40, it is determined that the waveform number counter HNC> 3, and in the case of Y, the process proceeds to S41. In S41, the relative on threshold value TRLRL <[current crest value c−previous crest value AMP
(B)] is determined, and in the case of N, S42
Proceed to. In S42, it is determined whether or not this time the positive / negative flag b = flag MT, that is, whether or not the pitch is changed.

By the way, in the initial state, the waveform number counter
Since HNC is 0 (see S301 in FIG. 9), N is determined in S40 and the process proceeds to S42. Then, for example, in the case of the waveform input as shown in FIG. 11, since b = 1 and MT = 0, S42
Proceed to S63 from.

In S63, it is determined whether the register RIV = 1 or not in order to check whether or not a peak having the same polarity is continuously input (whether it is double) or not. If Y, the process proceeds to S68. , N (if not double)
Proceeds to S64, where the following processing is performed. That is, in S64, the current peak value c is input to the previous peak value AMP (b), and the previous amplitude value AM is used for the relaive-off process.
RL1 is input to the amplitude value AMRL2 two times before. In this case, the content of AMRL1 is 0 (see S30 in STEP3). Further, in S64, the larger one of the previous peak value AMP () and the current peak value c is input to the previous amplitude value AMRL1. That is, the peak value having a large value among the two positive and negative peak values in the cycle is set to the amplitude value AMRL1. Then, in S65, it is determined whether or not the waveform number counter HNC> 8. Here, the waveform number counter (zero cross counter not on the pitch change side) HNC is incremented by one, and the count is incremented.

Therefore, the upper limit of the waveform number counter HNC is 9. Then, the process proceeds to S67 after the process of S65 or S66. In S67, the register RIV is set to 1, the content of the time storage register TFR is subtracted from the current zero crossing time, and the result is input to the period register TTR. This cycle register TTR is
The period information shown in FIG. Then, the current zero cross time t is saved in the time storage register TFR, and thereafter, the process returns (RET) to the main routine.

In the case of Y in S63, the process proceeds to S68, and it is determined whether or not the current peak value c> the previous peak value AMP (b). In the case of Y, the process proceeds to S69. In S69, the previous peak value AMP (b) is rewritten to the current peak value c, and the process proceeds to S70. In S70, it is determined whether or not the current peak value C> the previous amplitude value AMRL1. If Y, the process proceeds to S71, where the current peak value c is input to the previous amplitude value AMRL1.

If the determination of N is made in S68, the process immediately returns to the main routine. Therefore, only when the peak of the new input waveform is large, the amplitude value of the new waveform is registered. (In that case, it is considered that the peak of the overtone is not widened.) In addition, when N in S70 and when the process of S71 ends, the process returns to the main routine in the same manner.

As described above, the route is subjected to the following processing according to the example of FIG. MT = 0 ≠ b, RIV = 0, AMP
(1) ← c, AMRL2 ← AMRL1, AMRL1 ← max [AMP (0),
c (whichever is greater)], HNC ← (HNC + 1) = 1,
RIV ← 1, TTR ← (t−TFR), TFR ← t are processed. Accordingly, the difference between the time information from the previous zero-cross point of the same polarity (at STEP 2 → 3) to the current zero-cross point, that is, the cycle information has been found in the cycle register TTR.
Then, the process returns to the main routine and waits for the next zero cross interrupt.

Next, a description will be given of a case where the vehicle has proceeded to the route shown in S40 to S623. Now, since the waveform number counter HNC is 1 (see S66), the process proceeds from S40 to S42. In S42, in the case as shown in FIG. 11, since MT = 0 and b = 0, the result is Y, and the process proceeds to S43. In S43, it is determined whether or not the register RIV = 1.
Since the register RIV has already been set to 1 in the route (see S67), the determination in S43 is Y in this case, and S4
Proceed to 4.

In S44, it is determined whether or not the register STEP = 4.
In the case of, go to S45. In S45, the peak value c <60H this time
(H indicates a hexadecimal expression) is determined, and since the peak value is large, it becomes Y, and the process proceeds to S46. In S46, it is determined whether or not the amplitude value AMRL2 of the previous time AMRL2−the previous amplitude value AMRL1 ≦ ANE × the amplitude value AMRL2 of the last time before the current value. If Y, the process proceeds to S47 and the relative off counter FOFR is set to 0.
The relaive-off process will be described later. Then, in S48, a cycle calculation is performed. Specifically, (the current zero-cross time t-the previous zero-cross time data TF) is set in the register TOTO as the current cycle information tt. Then, the process proceeds to S49, in which the present cycle information
It is determined whether tt> frequency upper limit THLIM (upper limit after the start of sound generation). If Y, the process proceeds to S50.

The frequency upper limit THLIM of S49 is the upper limit of the permissible range of the frequency at the time of triggering (at the start of sounding) used in S36 of STEP3 (therefore, it corresponds to the pitch period that is the minimum as a period and is two to three semitones above the maximum sound fret) ).

Next, the following processing is performed in S50. That is, the register RIV is set to 0, the current zero-crossing time t is input as the previous zero-crossing time data TF, the previous peak value AMP (b) is input as the immediately preceding peak value e, and the current peak value c is set as the previous peak value c. It is input to the peak value AMP (b).

Then, after the process of S50, the process proceeds to S51, and in S51, it is determined whether or not the frequency lower limit TLLIM> the present cycle information tt, and Y
In the case of, that is, when the current cycle becomes equal to or less than the lower limit of the pitch extraction sound range during note-on, the process proceeds to S52.

In this case, the lower frequency limit TLLIM is set, for example, one octave below the open string scale. In other words, the allowable range is wider than the frequency lower limit TTLIM (see S37) of STEP3. By doing so, it becomes possible to cope with a frequency change due to operation of the tremolo arm or the like.

Therefore, the process proceeds to S52 only when the upper and lower limits of the frequency fall within the allowable range, and otherwise, the process proceeds to S49.
Return from S51 to the main routine.

Next, in S52, the cycle data TTP is input to the cycle data h extracted two times before, and the current cycle information tt is input to the cycle data TTP extracted last time. Then, in S53, the current peak value c is written to the perfority VEL, and the process proceeds to S54. S5
In the case of No.4, the no-chage level NCHLV> (the peak value e-
It is determined whether or not the current crest value is c), and in the case of Y, the process proceeds to S55.

That is, the previous peak value of the same polarity (e = AMP (b))
When the peak value c greatly changes, the difference exceeds NCHLV. In such a case, if the pitch is changed based on the extracted period information, an unnatural pitch It is likely that it will change. Therefore, when the determination of N is made in S54, the process returns to the main routine without performing the processing of S55 and thereafter.

Next, in the case of Y in S54, the relative off counter FOFR
It is determined whether or not = 0. When the later-described relaive-off process is being performed, the relaisive-off counter FOFR is not 0, but in such a case, the determination of N is made in S55 without performing the pitch change process (see S61). To return to the main routine. Then, when the determination of Y is made in S55, the process sequentially proceeds to S56 and S57.

Here, the two-wave ternary coincidence condition is determined. In step S56, the current cycle information tt × 2 ⁻⁷ <1 the current cycle information tt−the cycle data before the previous cycle hl is determined.
In this case, the current cycle information tt × 2 ⁻⁷ <1 the current cycle information tt−the content 1 of the cycle register TTR is determined, and in the case of Y, the process proceeds to S58.

That is, in S56, the current cycle information tt (S43
Is determined to be substantially equal to the value of the previous cycle data h (= TTP) (see S52), and in S57, the value of the current cycle information tt substantially matches the cycle TTR overlapping therewith. It is determined whether or not. The limit range is 2 ⁻⁷ × tt, and the value changes depending on the period information. Of course, this may be a fixed value, but better results can be obtained with the technique of this embodiment.

In the next S58, it is determined whether or not this cycle information tt> constant TTU. If Y, the process proceeds to S59, where the current cycle information t
It is determined whether or not t <constant TTW. If Y, the process proceeds to S60.
It should be noted that S58 and S59 are judgments for not allowing a sudden pitch change.

In other words, the constant TTU of S58 is now set to 0 in S301 of STEP3, and the constant TTW is similarly set to the value of MAX. When passing through this flow for the first time, Y is always determined in S58 and S59. After that, in S62 described later, the constant TTU includes:
(17/32) tt (period information of approximately one octave high tone) is set, and (31/16) tt (period information of approximately one octave low temperature) is similarly set in S62 for the constant TTW. Therefore, when there is a sudden octave up (this occurs when the mute operation is performed with the fret released) or an octave down (this occurs when the waveform peak is missed). Is unnatural if the pitch is changed, so branching is performed without changing the pitch.

If Y is determined in S58 and S59, then S6
Go to 0. In S60, it is determined whether or not the register STEP = 4. In that case, the process proceeds to S61. In S61,
Change pitch from microcomputer MCP to sound source SS (this cycle information t
t), and proceeds to S62, where the current cycle information tt
The time constant is changed in response to the
2) x is rewritten to the current cycle information tt, and the constant TTW is rewritten to (31/16) x current cycle information tt.

That is, as will be described later, STEP = 5 is obtained only when the rela- tive-off process is performed. In that case, the time constant change is performed without performing pitch change. The processing of the time constant change means that the microcomputer MCP sets data based on the value of the current cycle information tt in a register inside the time constant conversion control circuit TTC of FIG. This is as described above.

The following S621 is the same as that already described in S310 of FIG. 9, and in S621, the cycle tt extracted this time and the constant HFOP
Judge whether or not the difference is within 5% of HFOP. If Y in S621, set the value of 1/40 to register ANE in S622. If N in S621, set register ANE in S623.
Set the value of 1/20 to Then, the process returns to the main routine (RET.). Therefore, as described above, the routine performs the following processing as shown in FIG. That is, HNC = 1, MT = 0 = b, RIV = 1, FOFR ← 0, tt ←
(T-TF), RIV ← 0, TF ← t, e ← AMP (0), AMP
(0) ← c, h ← TTP, TTP ← tt, VEL ← c, and further satisfying the three conditions of TTP ≒ TTR ≒ tt, TTU <tt <TTW, AMP (0) −c <NCHLV, Make pitch change according to tt.
Thereafter, TTU ← (17/32) × tt and TTW ← (31/16) × tt are performed. Then, ANE ← 1/20 or 1/40 is performed.

Therefore, the pitch of the actual sound source SS is changed in the route, and the route processing is performed in the subsequent zero cross interrupt, and similarly, the route processing is performed in the subsequent zero cross interrupt. Thus, in the route, the period is simply extracted (see S67), and in the route, the actual pitch is changed (see S61), and the time constant change processing (S67) is performed.
62).

In step S40 in step 4, after counting up so that the waveform number counter HNC exceeds 3 in step S66, a determination of Y is made, and then the process goes to step S41 to detect the condition of relative on. This, c-AMP
(B)> TRLRL, and when the current amplitude value exceeds the threshold value TRLRL as compared with the previous amplitude value AMRL1, that is, when the same string is picked again after the string operation (such as tremolo playing method) According to this)
In this case, from S41 to perform the relativity on processing in S41
Proceeding to S78, the cycle CHTIM of the highest tone fret (for example, 22 fret) is set in the time constant change register CHTRR of the time constant conversion control circuit TCC. Thereafter, the process proceeds to S06 in FIG. 5, and after note-off of the musical tone being sounded, re-sounding is started.

According to the normal performance operation, the process proceeds to S40, S41, and S42, and proceeds to the above-described route or route.

Next, the relative-on process will be described with reference to FIGS. In other words, when shifting from the fret operation state to the open string state, the amplitude level of the waveform suddenly drops, and the difference between the previous peak value AMRL2 and the previous peak value AMRL1 exceeds ANEAMRL2. Then, the process proceeds from S46 to S74. Here, the value of the register ANE is such that the pitch is 1 for an open string.
If the pitch is one octave above, it is 1/40, otherwise it is 1/20. Therefore, the former performs relaive-off processing even for gentle attenuation of the waveform signal. And the relative on-counter FOFR is a constant
S74 to S7 to count up until ROFCT is exceeded
Proceed to 5. At this time, the process goes from S75 to S48 and performs the processes of S49 to S55. However, since FOFR is not 0, the process returns to the main routine without changing the pitch immediately before the start of the relativ-on process.

When it is determined as N in S74, that is, in the example of FIG. 13, when the value of FOFR becomes 3 (ROFCT is 2), S
Go from 74 to S76.

However, if the judgment of Y in the judge of S46 is at least once, the process proceeds from S46 to S47, and the FOFR is reset. Therefore, if the condition of S46 is not satisfied continuously for the number of times specified by ROFCT, the relative-off process is not performed. If the value of ROFCT is set to a large value for a string having a high pitch, the relative-off processing can be performed for any of the strings after a substantially constant time has elapsed.

Then, when going from S74 to S76, the relative off counter FOFR is reset, the register STEP is set to 5, and the process proceeds to S77 to instruct the sound source SS to turn off the note. This STEP is 5
In the state of, the pitch extraction processing is executed in the same manner as in STEP 4, but since the processing proceeds from S60 to S62 without passing through S61,
The pitch is not changed for the sound source SS. However, S6
Time constant change processing is performed according to the cycle extracted in 2.

Then, in the state of STEP 5, the relativity-on process is accepted (S41, S78).
In the main flow of the figure, when it is detected that the vibration level has decreased, STEP becomes 0 in M14, and the process returns to the initial state.

Note that AMRL1 and AMRL2 used in S46 are made in S64, and the peak having the larger level (one of the maximum peak and the minimum peak) in one cycle is set to this value, and FIG. In the example, the maximum peak a _k is always larger than the minimum peak b _k −1, and an + 1 and an + 2, an + 2 and an + 3, an
Both the difference between +3 and an + 4 exceeds a predetermined value.

At this time, in the route processing, since the minimum peaks bn + 1, bn + 2, and bn + 3 have been extremely reduced, the determination of N is made in S54, and the process returns to the main routine, and the pitch change processing is not performed.

Next, a description will be given of a process performed when a double temperature having an octave relationship, that is, a high octave sound or a low octave sound is continuously detected during pitch extraction.

As described above, in S58, when tt does not exceed the TTU, that is, when it becomes smaller than the value TTU obtained by multiplying the previously extracted cycle by 17/32, the process proceeds to S76. In other words, when an octave higher sound is extracted, it is considered that the finger has been released from the designated fret and the mute operation has been performed.Then, the output goes from S58 to S76 without outputting an octave higher sound, and S76, as in the case of relative off, is output. The sound generation of the sound is stopped by the processing of S77.

In S59, when tt does not exceed TTW, that is, when ttW is larger than the value TTW which is 31/16 times the previously extracted cycle, the process returns to the main routine without proceeding to S60.

This state is shown in FIG. Normally, when the waveform near the note-off is very small, the waveform is picked up by a crosstalk of a hexapickup or resonance of a body due to another picking. Then, for example, an input waveform as shown in FIG. 14 may be obtained, and an input waveform one octave lower may be continuously detected.

In such a case, if no processing is performed, a sound immediately below the octave is output, which is extremely unnatural. Therefore, even if Tan + 2 ≒ Tan + 3 ≒ Tbn + 2 is detected in S57 and S56, since Tan + 3> Tan + 1 × (31/16), the process returns from S59 to the main routine without changing the pitch.

Next, a case where a doubled waveform is extracted, that is, a case where zero-cross points having the same polarity continuously arrive will be described. FIG. 15 shows an example in the case of MT = 1. Since the fundamental wave period and the period of the harmonic component are non-integer multiples, the phases of the harmonics are shifted, and the zero crossings of the same polarity are detected. You have to make sure you don't make the wrong pitch changes.

Therefore, STEP at the time of zero cross written as double in the figure
In the process of 4, the process goes from S42 to S43, and in S43, the determination of Y is made and the process goes to S72. Here, the magnitudes of (an + 3) and (an + 2) are compared. If (an + 3) is greater than (an + 2), a determination of Y is made in S72, and the value of (an + 3) is added to AMP (1). Is set, and if not, no change processing is performed.

By the way, in the case of this double, no extracted time data is used, so that the cycle information Tan + 3 does not change at all. Of course, pitch change based on the cycle data is not performed.

Similarly, FIG. 16 shows an example of the case of doubled waveform, where MT = 0.
The state of is shown. At this time as well, the state of double doubling occurs where double doubling is indicated in the figure. At this time, the process goes from S42 to S63, makes a Y determination, and goes to S68. S68
Then, in this case, (an + 2) is compared with (an + 3), and only when (an + 3) is larger than (an + 2), the flow goes to S69 to rewrite AMP (1). In this case, the comparison between the previous amplitude value AMRL1 and the current amplitude information (peak value c) is further performed in S70.
If Y, the process proceeds to S71, and the current amplitude information c is set to the previous amplitude value AMRL1.

In this way, even when the waveform is doubled due to the overtone, the pitch change processing is not performed unless S56 and S57 are satisfied.

As described above, according to this embodiment, the extracted pitch is a pitch (HFOP) that is approximately one octave above the open string pitch of the string.
Judgment is made as to whether or not it indicates (FIGS. 9 S310 and FIG. 10)
As a result, even if the finger is released from the fret, it is found that the pitch is approximately one octave higher than the open string pitch, and if the pitch is determined to be approximately one octave higher than the open string pitch, the value that determines the damping rate when the relative off is judged is set to a gradual value. That is, ANE is set to 1/40 (S311, identification S622), and in other cases, ANE is set to 1/20 (S312, S623). Then, as shown in S46 of FIG. 10, the condition of the relaive off is set to AMRL2-AMRL1ANE.
・ AMRL2.

By doing so, even if the fret operation is performed at a pitch approximately one octave higher than the open string pitch and the string is picked, the finger is released from the fret and muted. It is possible to surely detect the same, and it is possible to obtain the same result when performing a muting operation from a fret operation of another pitch.

Further, according to the above embodiment, if the attenuation rate of the waveform signal level of the larger of the absolute value of the maximum peak value and the absolute value of the minimum peak value of the input waveform signal is greater than or equal to the predetermined ratio, the mute operation is performed. Therefore, even if the input waveform signal is attenuated on one side (this is because the waveform passing through a low-pass filter is generally not vertically symmetrical), or even if the input waveform signal is in an area where the peak value is small, the relative off detection can be performed. It is possible, and the tone which the player instructed to mute does not continue to be emitted.

That is, as shown by S64 in FIG. 10, the previous amplitude value A
The largest peak value in one cycle is input as MRL1, the value one cycle before is stored in the amplitude value AMRL2 two times before, and as shown in S46 Relative off is determined from the attenuation ratio of the amplitude values AMRL1 and AMRL2, and if this condition is satisfied continuously for a predetermined number of times, it is determined that the mute operation has been performed, and S74, S76, S7
Go to 7 and take note off. In this case, it is the relative off counter FOFR that counts the number of reductions.
The constant ROFCT defines the predetermined number of times. Also, S
As shown by 47, the counter FOFR is cleared if there is no decrease of ANE AMRL2 or more even once (see FIG. 13).

For this reason, according to this embodiment, it is possible to detect the relative off even if the input waveform signal is attenuated on one side or the input waveform signal is in an area where the peak value is small.

The detection of the peak value attenuation of the waveform signal is not limited to the above embodiment, but may be another method. For example,
When both the maximum peak value (positive peak value) and the minimum peak value (negative peak value) of the waveform signal generated by the string operation are both attenuated by a predetermined level or more, the relative off process is performed. To do.

Also in this case, if the extracted pitch indicates a pitch that is approximately one octave above the open string pitch, the condition of the peak value attenuation ratio is made milder, and a smaller attenuation ratio is detected as compared with other pitches. To give a mute instruction.

Further, in the above-described embodiment, the period is extracted from the interval of each zero crossing point next to the maximum peak point and the minimum peak point. However, other methods, such as the time interval between the maximum peak point and the minimum peak point, are used. May be extracted. Further, the circuit configuration can be variously changed in accordance with it.

Furthermore, in the previous embodiment, the present invention was applied to an electronic guitar (guitar synthesizer), but is not limited to this. The present invention is applicable to various types of musical instruments or devices that generate a sound signal different from the original signal by performing pitch extraction.

〔The invention's effect〕

As described above, according to the present invention, it is determined whether or not the string vibration pitch detected by the pitch detecting means is a pitch substantially matching the pitch one octave above the open string, and If the determining means determines that the pitch of the vibrating string is substantially equal to the pitch one octave above the open string during the generation of the musical tone according to the instruction of the above, the amplitude of the string vibration detected by the amplitude detecting means Is greater than or equal to a first predetermined value, the instructing means to mute the musical tone being generated and determine that the pitch of the vibrating string is not substantially equal to the pitch one octave above the open string. In this case, when the attenuation rate of the amplitude detected by the amplitude detection means becomes equal to or more than a second predetermined value larger than the first predetermined value, the mute instruction means instructs mute of the musical tone being generated. What pitch Can be reliably detected, and the sound intended by the player can be muted.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing the overall configuration of an electronic musical instrument input control device according to the present invention; FIG. 2 is a block diagram showing an example of a pitch extraction digital circuit shown in FIG. 1; FIG. 4 is a flowchart showing an interrupt processing routine of the microcomputer of FIG.
FIG. 4 is a flowchart showing a main processing routine of the microcomputer of FIG. 2, and FIGS. 5 to 7, 9 and 10 are for explaining the operation of each step of the microcomputer of FIG. 8 and FIGS. 11 to 17 are timing charts for explaining the operation of each step. PA: Pitch extraction analog circuit, PD: Pitch extraction digital circuit, MCP: Microcomputer, SS: Sound source, PEDT: Peak detection circuit, ZTS: Zero-cross time acquisition circuit, TCC:
… Time constant conversion control circuit, PVS …… Crest value capture circuit.

Claims (3)

(57) [Claims] 1. An amplitude detecting means for detecting an amplitude of a string vibration; a pitch detecting means for detecting a pitch of the string vibration; and an instruction to generate a musical tone having a pitch corresponding to the pitch detected by the pitch detecting means. Musical tone generation instructing means; determining means for determining whether the pitch detected by the pitch detecting means is substantially equal to a pitch one octave above the open string; If the determining means determines that the pitch of the vibrating string is substantially equal to the pitch one octave above the open string, the amplitude detecting means determines that the attenuation rate of the amplitude is equal to the first pitch. When the predetermined value is equal to or greater than the predetermined value, the sound generation tone is instructed to be silenced, and when the determination unit determines that the pitch of the vibrating string is not substantially equal to the pitch one octave above the open string, Said shake And a mute instruction means for instructing mute of the musical tone being generated when an attenuation rate of the amplitude detected by the width detection means becomes equal to or more than a second predetermined value larger than a first predetermined value. String instruments. 2. The amplitude detecting means detects an amplitude of an electric signal corresponding to the string vibration as an amplitude of the string vibration, and the muffling instruction means includes a positive / negative decay of the amplitude detected by the amplitude detecting means. The electronic stringed musical instrument according to claim 1, wherein the mute instruction is performed based on at least one of the rates. 3. The amplitude detecting means detects an amplitude of an electric signal corresponding to the string vibration as an amplitude of the string vibration, and the muffling instruction means includes a positive / negative decay of the amplitude detected by the amplitude detecting means. The electronic stringed musical instrument according to claim 1, wherein the mute instruction is performed based on both of the rates.