JP2829987B2 - Pitch determination device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention automatically obtains a musical tone having a desired pitch (tuned pitch) without requiring a mechanical tuning operation for a musical instrument. The present invention relates to a pitch determining device capable of performing the following.

[Prior art and its problems] In recent years, with the rapid development of electronic technology, various forms using electronic technology instead of traditional natural stringed instruments such as oriental koto, Indian sitar, western violin and guitar Various types of electronic string instruments, for example, electric guitars, electronic violins, and guitar synthesizers have been developed.
This electronic stringed instrument generally converts the vibration of a string that is stretched into an electric signal and, based on the electric signal, emits a musical tone at a required tone and volume. However, as in the case of a natural stringed instrument, the string can be vibrated by pressing a predetermined fret position of a string stretched with a predetermined tension on a string pressing operation surface (fingerboard surface). A common feature in producing a musical tone having a pitch defined by the above-described pressed string fret position while operating the corresponding string under a state in which the length, that is, the string length is appropriately defined by a fingertip. Having. Therefore, in the electronic stringed musical instrument, as in the case of the natural stringed musical instrument, all the strings that are stretched are tensioned with an appropriate tension for each string, and are fixedly arranged on the fingerboard. In relation to each fret position, all the strings stretched on the fingerboard are also stretched at an appropriate string length for each string, that is, in the proper tuning state as in the above two cases. It is necessary that each string be stretched. If each string is not tensioned at an appropriate tension and at an appropriate string length in relation to each fret position, a musical tone is produced at an incorrect pitch. In particular, in the case of a guitar synthesizer that produces a wide variety of tones by manipulating the strings,
The string vibration period information defined by the effective vibration length of the strings is extracted, and based on the string vibration period information, the tone of the corresponding pitch is controlled to generate sound. Otherwise, incorrect string vibration period information will be extracted, and as a result, a musical tone having an incorrect pitch will be generated. Therefore, it is particularly necessary that each string be stretched in an appropriate tuning state.

Conventionally, two tuning methods have been known as a measure for optimizing the tuning state of each string. One is a method called pitch tuning or fine tuning. This tuning method uses a pincushion device (called a peg or the like) provided on the head or torso to increase or decrease the tension of the string being stretched, and to change the tension of the string. This is a method of changing the degree of tension. The other is a method called harmonic tuning or string length tuning. This tuning method changes the distance between a pair of string support members (generally called bridges, bridges, nuts, etc.) that support both ends of a stretched string, and changes the length of the string. It is a method of changing the chord length.

By the way, recently, according to the two tuning methods described above, a new tuning device capable of realizing the two tuning methods almost simultaneously has been developed (for example, Japanese Patent Laid-Open No. 58-1639).
No. 97 publication. ). Conventionally, this tuning device is designed to set a proper tuning state by independently operating the string tension changing mechanism and the string length changing mechanism when changing the tension and the string length of each string. In view of the fact that the tuning work requires a great deal of labor and time. According to this tuning device, after appropriately setting the string length of each string, the string length of each string set to an appropriate string length is kept in a state where one end of the string is firmly constrained. As a result of being able to increase or decrease the degree of tension of each string without changing it, there is an advantage that an appropriate tuning state can be set relatively quickly and easily as compared with a conventional tuning apparatus.

However, using the tuning device described above,
Even in the case of obtaining an appropriate tuning state, for each string, a member for changing the tension of the string or a string supporting member for supporting each string may be finely adjusted as appropriate for each string, or may be adjusted in the longitudinal direction of the neck. There is a problem that a mechanical tuning operation such as moving is required.

Also, even if each string is tuned to an appropriate tuning state before the performance, during the performance, for example, arming operation by the vibrato arm (modulating the pitch of the generated musical tone uniformly to modulate the pitch) A fingering operation, a choking operation with a fingertip (an operation of raising or lowering a string being pressed after picking to raise or lower the pitch of a generated musical tone, also referred to as a bending operation).
Sliding operation (operation to modulate the frequency of the tone being sounded by sliding the finger being pressed along the longitudinal direction of the string after picking), fingering operation (similarly,
After picking or before picking, if the user frequently changes the position of the finger while pressing a string to obtain musical tones of different pitches, etc.), the tuning state of the string is often distorted due to the operation. When such a situation occurs, it is not possible to immediately correct the tuning state within a short time until the next performance, and as a result,
There is also a problem that a musical tone must be continuously generated at a pitch not intended by the player (a pitch in which the tuning state is out of order).

Furthermore, it is difficult for a beginner to set the tuning state of each string to an appropriate state for each string, and in some cases, the strings are cut too tightly. In order to prevent such a situation, there is a problem that it is necessary to request the expert to perform a tuning operation of the string or to use a tuning setting device in particular.

[Purpose of the Invention] The present invention has been made to solve the above-mentioned conventional problems. Even when the strings are not stretched in an appropriate tuning state, a simple tuning initial setting operation can be performed. It is an object of the present invention to provide a pitch determining device capable of generating a musical tone having an accurate pitch, similar to a case where a string is played in an appropriate tuning state. Still another object of the invention is often performed after a string. By providing a pitch determining device that can perform tuned pitch control by following operations that change the vibration frequency of a string, such as sliding operation, fingering operation, choking operation, arming operation, etc. is there. It is a further object of the present invention to provide a pitch determining apparatus capable of controlling the initial and after pitches of a well-tuned input vibration signal.

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a basic period of a string vibration extracted by a pitch extracting means when a string is string-operated at a predetermined string-pressing position prior to performance. The string stretching state related to the reference tuning is determined and inspected based on the pitch, and at the time of sounding start instruction, the fundamental period extracted by the pitch extraction means is tuned based on the determination result of the string state. If the pitch is converted to high specified data and the initial pitch is controlled, and a new basic cycle is extracted by the pitch extracting means after the instruction to start sounding, the cycle is returned to the string state determination result in response to this. It is characterized in that after-pitch is controlled by converting into pitch-designated data tuned based on the pitch.

Further, according to the present invention, from the input vibration signal,
Pitch extracting means for extracting pitch information corresponding to the basic period of the vibration signal, reference pitch storing means for storing desired reference pitch information representing a desired reference pitch, and extracting by the pitch extracting means before playing. Pitch sample information storage means for storing the obtained pitch information as pitch sample information, and when the pitch information is extracted from the pitch extraction means in response to the rise of the vibration signal during the performance, the pitch information is Initial pitch control means for changing based on desired reference pitch information and the pitch sample information, and new pitch information is extracted from the pitch extraction means during operation after the operation of the initial pitch control means. And changes the pitch information based on the desired reference pitch information and the pitch sample information. Pitch determining apparatus comprising: the Futa pitch control means is provided.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First Embodiment FIG. 1 shows an appearance of an electronic stringed musical instrument according to a first embodiment.
This electronic stringed instrument mainly includes a body 101 and a neck 102 having a finger board 102a. On the finger board 102a, a large number (four in this embodiment) of frets 102b are unequally spaced according to 12 equal temperament, that is, as in the case of a normal guitar, the head 124
Is arranged so that the fret interval FL becomes gradually shorter from the body 101 toward the body 101 side. A tremolo board 104 having a vibrato arm (treme arm) 103 for changing the tension of a string 107 of the electronic stringed instrument is mounted on the body 101 so as to be rotatable about a support shaft 105. I have. On the upper part of the substrate 104, a string support 1
10 are integrally formed, and the string 107 of the electronic stringed instrument is
Is fixed at one end. Further, at a substantially central portion on the tremolo substrate 104, string-independent pickups 111 are provided as string vibration detecting means.
Thus, the vibration of the string 107 of the electronic stringed instrument is detected.

On the other hand, a proximal end 126 of a head 124 attached to the distal end of the neck 102 in FIG.
27 is formed, where the other end of the string 107 is fixed. Length GL of string 107 from string support 110 to string support 127
Defines the length of vibration of the string 107 in the open state.

Next, an electronic circuit configuration used in the electronic stringed musical instrument will be described with reference to FIG.

In FIG. 2, a hexapickup 1 which is a pickup means 111 provided independently for each of the first to sixth strings 107... Detects the vibration of each string 107. It converts it into an electric signal. The string vibration signal output from the hex pickup 1 is applied to a low-pass filter 3 via an amplifier 2, where a higher-order harmonic signal is removed. It is desirable that the cutoff frequency of the low-pass filter 3 is set to be different for each string. The output of the low-pass filter 3 is applied to a pitch extracting circuit 4 as a pitch extracting means. The pitch extracting circuit 4 extracts pitch information which is a fundamental period of the vibration of each of the strings 107. It is sent to a processing circuit 5 comprising a CPU of a microcomputer. In this embodiment, the pitch extraction circuit 4 compares the positive peak value and the negative peak value of the string vibration signal detected by each of the string independent pickups 1... The peak associated with the peak point on the same side (ie, the positive side or the negative side) detected in the same manner as the next point (ie, the positive peak point or the A so-called peak / zero-cross point combination method is adopted in which a time interval ending at the zero-cross point immediately after passing through the negative peak point) is detected as a period of the string vibration, but the method is not limited to such a method. Various types can be employed.

The string vibration signal from each low-pass filter 3 is also applied to a vibration level detection circuit 35, where the level of the string vibration signal is detected and sent to the processing circuit 5 in digital form. The processing circuit 5 determines that the tone generation has started (starting the string operation) when the sent string vibration level exceeds a predetermined ON level, and when the string vibration level falls below a predetermined FF level, It is determined that the operation has ended (end of the string operation). Furthermore,
The processing circuit 5 measures the maximum value (peak level) of the string vibration level as the strength of the string.

The electronic stringed instrument of this embodiment is provided with a mode changeover switch 6 for switching between two modes, preset and play, as its features. This mode switch 6
Are set to a preset mode used when inspecting the state of each string 107 of the electronic stringed instrument before performance, and a play mode used during performance in which pitch control electronically tuned based on the inspection result is performed. Is used to change over.
When the mode switch 6 is switched to the preset side as shown in FIG. 2, the preset mode is set, and when the mode switch 6 is switched to the play side, the play mode is set.

Also, as features of the configuration of this embodiment, the first string open period register 7a to the sixth string open period register 7f, the conversion coefficient operation circuit 8, and the first string conversion coefficient register used when the preset mode is set. A conversion coefficient register 9f for the 9th to sixth strings and a string pressing position / period table memory 10 are provided. Each of the first to sixth strings 107
... First string open cycle register provided for each
7a to 6th string open cycle register 7f stores a predetermined string pressing position at which the length of string vibration becomes a predetermined length for each of strings 107,... In the preset mode, and an open string fret in this embodiment. The open string period data TM measured when the player performs a ball-playing operation at the position (0th fret position) is stored. For example, a certain string 10
When a predetermined pitch is extracted by the open string picking of 7, the open string cycle data TM of the string 107 is written by the processing circuit 5 as string state determination information into the corresponding open cycle registers 7a to 7f.

The conversion coefficient cycle calculation circuit 8 converts the open string cycle data TM stored in the first to sixth string open cycle registers 7a to 7f into the open string at the top of the string pressing position / cycle table memory 10. Compared with the periodic data TO
Calculate TO / TM and store the result in the first string conversion factor register 9
Write to the conversion coefficient register 9f for a to sixth string. Thus, it is confirmed that the measured period TM of each string is a period corresponding to the state of the open string of each string.

Here, the contents of the string pressing position versus period table memory 10 will be described with reference to FIG. In the table shown, X
Cent represents the string pressing position, 0 cent represents the 0th fret position (open string fret position), 100 cents represents the first fret position, 200 cents represents the second fret position, and so on. In the illustrated example, since the resolution of the string pressing position is set to 10 cents, the address 0 of the table corresponds to the open string fret position, and the address 10 of the table corresponds to the first fret position. The column of the Y cycle is the data of the table, and here the cycle data Y (= 10
00 × 2− ^{x / 1200} ) is stored. The reason that the possible range of the string pressing position is the 0th fret position (open string fret position) to the 28th fret position is related to the fact that there are 24 frets on the fingerboard 102a of the electronic stringed instrument in FIG. ing. The reason why the table is larger by four frets is to take into account that the vibration frequency of the string 107 increases due to the operation of the tremomono arm 103 and the choking (bending) operation on the string 107.

Returning to FIG. 2, the key code conversion circuit 11, which is used during the setting of the play mode, tunes the period measured for the vibration of each of the strings 107... Generated by the string operation. The tuning is performed by converting the data into key code data (pitch specification data) for specifying the period of the string. More specifically, when a measurement cycle is given, the key code conversion circuit 11 outputs information on the state of the string determined in the previous preset mode, here, the conversion coefficient register 9a.
The conversion coefficient data of 換算 9f is read, and the conversion coefficient is multiplied by the measurement cycle to convert the cycle. The converted cycle serves as a key when the key code conversion circuit 11 searches the string pressing position / cycle conversion table memory 10. That is, the table address having the data of the converted cycle indicates the string pressing position of the string related to the measurement cycle. Key code conversion circuit 11
Adds the key code corresponding to the open state of the tuned string (stored in the open string key code register 12 (12a to 12f)) to the string pressing position data detected by the table search, thereby obtaining the desired key code data. Generate

In this embodiment, the resolution of the tuning key code generated by the key code conversion circuit 11 is different between when the musical sound is started and after. Specifically, the key code conversion circuit 11 generates a key code with a resolution of a semitone (100 cents) at the start of sounding, and generates a key code with a finer resolution of 10 cents (equal to the resolution of the table memory 10) during sounding. Generate. The RUN FLAG signal is supplied from the processing circuit 5 to the key code conversion circuit 11 to determine which resolution is to be selected. The RUN FLAG signal takes logic "0" at the start of sound generation, and takes "1" during sound generation. In the key code conversion circuit 11, the conversion coefficient register 9a for each string
To select the open string key code registers 12a to 12f, the string number data is transferred from the processing circuit 5 to the key code conversion circuit together with the measurement cycle data (performance pitch information).

Referring now to FIG.
The data format of the key code to be placed in is described.

In this embodiment, the electronic stringed instrument of FIG. 1 has the same open string pitch (frequency) as a normal 6-string guitar under proper tuning conditions.
Is assumed. Therefore, the open note of the tuned first string is E4, and the open string of the second string is B
3, 3rd string is G3, 4th string is D3, 5th string is A2, 6th string is E2
It is. The key code corresponding to the name of each open string is stored in the open string key code register as shown in FIG. 4 (a). These key codes represent the pitch by a linearly changing numerical value with the key code for the pitch name C0 being zero and one octave being 120 (see FIG. 4 (b)). When expressed by an equation, the key code KC is given by the logarithm of the frequency KC = 120 log ₂ (K × F). Where F is a frequency and K is a constant,
KF = 1 at frequency F (= 16,352Hz) at pitch C0
Becomes Expressing the pitch in such a logarithm has the advantage that the key code range can be reduced with respect to the audible frequency range, and the data length can be reduced to compress the data. Intermediate interfaces (eg, MIDI standard) are employed. However,
The present invention is not limited to this data expression, and any other pitch expression is possible.

Returning to FIG. 2, the key code for the tuned string generated by the key code conversion circuit 11 is used as pitch designation data as a tone generator circuit.
Supplied to 13. Further, the tone generator 13 is supplied with a signal of a sound generation start / end instruction (including a peak level data of a string vibration as a touch parameter of a string force at the time of sound generation) from the processing circuit 5. At the start of sound generation, the tone generator circuit 13 generates a frequency or a phase signal from the key code data in semitone steps from the key code conversion circuit 11 and generates a musical tone waveform of each phase, thereby generating a musical tone of a designated pitch. If there is a change in the vibration frequency of the string 107 during sounding, it responds to the key code having a resolution of 10 cents from the key code conversion circuit 11 indicating the change, and the changed tone of the new pitch is reproduced. Form. The musical sound generated by the tone generator 13 is supplied to the audio system 14 and output to the outside as an acoustic signal.

The operation of the embodiment having the above configuration will be described below.

First, a description will be given of a preset mode in which the state of each string 107 for tuning is determined and inspected. The preset mode is set by switching the mode changeover switch 6 to the preset side. In this mode, the player plays the strings with each string 107 opened. As a result, the open period of each string 107 is extracted by the pitch extraction circuit 4 and passed to the processing circuit 5. The processing circuit 5 directly or indirectly calculates the open period of each string sent from the pitch extraction circuit 4 (for example, a result TM of sampling the period data in an internal buffer and performing an averaging process). It is stored in the open period registers 7a to 7f. When the measurement of the open period is completed, the conversion coefficient calculation circuit 8 is activated, and calculates the conversion coefficient according to the flow of FIG. That is, in step A2, the open period registers 7a to 7f for the string ST are accessed, and the data TM
Take in. In the next step A3, the start address of the string pressing position versus period table memory 10 is accessed, and the period TO of the open string placed on the table is loaded. Then, a ratio CAL between the measured open period TM and the open period TM of the table is calculated (step A4), and the result is stored in the conversion coefficient registers 9a to 9f as a conversion coefficient of the string ST (step A5).

As can be understood from the above description, in the preset mode, the stretched state of each string 107 is determined in the form of measurement open period data or conversion coefficient data. The latter conversion coefficient converts the measured period into a corresponding period on the string pressing position-period table memory 10 in a later play mode,
Used to detect the string pressing position. Note that the calculation of the conversion coefficient may be appropriately performed during the play mode.

Next, the electronic tuning control during the play mode will be described. FIG. 6 shows a flow of the operation of the embodiment in the play mode. The flow shown is for any one string. FIG. 7 exemplifies a waveform of a string vibration generated as a result of a string operation on an arbitrary string and a tone waveform generated by the tone generator circuit 11 based on the string vibration. First, string 10
7 is stationary, since ON FLAG = 0, the processing circuit 5
Is satisfied in step B-1. Since the string vibration level given from the string vibration level detection circuit 35 is also zero or nearly zero, it is confirmed in step B-2 that the string vibration level has not reached the predetermined ON level. When there is a string, string vibration rises as shown in FIG. 7 (a). The vibration level L1 in FIG. 3A is higher than the ON level.
Therefore, in the pass following the occurrence of the vibration level L1, the check in step B-2 is established, and in step B-3, ON FLAG for starting sound generation is set.

With the occurrence of the string vibration, the calculation of the cycle is executed by the pitch extraction circuit 4, and based on the result, the processing circuit 5 determines the initial pitch (cycle). That is, since the check ON FLAG = 0 in step B-1 is not established, and the check RUN FLAG = 0 in the next step B-4 is established, the process proceeds to step B-5 where it is determined whether or not the first pitch is determined. Find out. Now, assuming that the cycle T1 shown in FIG. 7 (a) is the first fixed cycle, the check of step B-5 of the next pass in which this cycle T1 is obtained is established.
In this case, the processing circuit 5 converts the performance pitch information into a string number,
It is passed to the key code conversion circuit 11 together with the RUN FLAG. As a result, as shown in step B-6, the key code conversion circuit
At 11, a tuning key code is generated in semitone units (in steps of 100 cents). Further, as shown in step B-7, the processing circuit 5 generates a peak of the vibration level (in the case of FIG. 7A, the larger of the vibration levels L1 and L2) as the touch parameter.

The key code and the peak level thus generated are sent to the tone generator 13 together with the tone generation start signal as shown in step B-8. As a result, the tuned pitch as shown in FIG. Is generated by the tone generator 13. Thereafter, the processing circuit 5 sets RUN FLAG to indicate that the musical tone is being generated (step B-9).

Therefore, after the start of sound generation, the check RUN FLAG = 0 in step B-4 is not satisfied, and it is checked in the next step B-10 whether the vibration level has become lower than the OFF level. Step B-11 is performed during the OFF level or higher.
The processing circuit 5 checks whether or not the period has changed. If the period T2 in FIG. 7A is a changed period, the condition of step B-11 is satisfied, and the processing circuit 5 sets the new period T2 together with the string number ST and the RUN FLAG as the key code. Send to conversion circuit 11. In response to this, the key code conversion circuit 11 calculates the tuned key code with a resolution of 10 cents higher than that at the start of sounding (step B-).
12). This high-resolution key code is supplied to the tone generator circuit 13 (step B-13), which makes it possible to finely change the pitch after the start of sound generation.

The string vibration once generated attenuates over time after the string operation. In FIG. 7 (a), at time OFF, the vibration level is lower than the predetermined OFF level. At this time, the condition shown in step B-10 of the flow of FIG. 6 is satisfied, and the processing circuit 5 sends a tone generation end signal to the tone generator circuit 13 in step B-14, and the tone generated by the tone generator circuit 13 is generated. To mute the sound. Further, the processing circuit 5 resets RUN FLAG and ON FLAG to indicate that the string 107 has transitioned to the stationary state (step B-15).

FIG. 8 shows details of the processing of the key code conversion circuit 11 executed in steps B6 and B-12 in FIG. The extraction pitch (measurement period) IN, the string number ST, and the RUN FLAG shown in C-1 are data input from the processing circuit 5. Upon receiving these data, the key code conversion circuit 11 makes a string in step C-2.
The conversion coefficient registers 9a to 9f for ST are loaded into the internal CAL register. Next, the conversion coefficient CAL is multiplied by the measurement cycle IN to obtain a conversion cycle IN corresponding to the table memory 10 (step C-3). The address having the conversion cycle IN indicates the pressed position of the string ST. Therefore, in the subsequent steps C-4 to C-12, the string pressing position / period table memory 10 is searched to detect the address having the period data that best matches the conversion period IN. As shown in FIG. 3, the contents of the string-pressing position-period table memory 10 decrease in order of address. Using this, a two-branch search of the table memory 10 is performed in FIG. That is, in step C-4, "-1" is set in the L0 register, and the size N of the table memory 10 is set in the H1 register (280 in FIG. 3).
Initialize. One half of the value of L0 and the value of H1 becomes a pointer P to the table memory 10 (C-9), and the cycle data [P] at the address indicated by the pointer P is compared with the conversion cycle IN (C- 7). If the conversion period IN is longer, the target address should be a younger address than the current pointer P, and if the conversion period is reversed, the target address should be at a higher address. Therefore, in the former case, P is substituted for H1 (C-8), and in the latter case, P is substituted for L0. As a result, every time the loop C-5 to C-9 is performed, H1 and L0
Is half, and at step C-5, L0 + 1 ≧
H1 holds. At this point, the value of H1 or the value of L0 indicates the address having the cycle data closest to the conversion cycle in the table memory 10, that is, the string pressing position of the string given the measurement cycle.

Which of the addresses H1 and L0 is closer to the conversion period IN is determined, and the results of storing the result in the N register are steps C-10 to C-12.

The value of the N register obtained by the above processing is the string ST
Are expressed in units of 10 cents, which is the resolution of the table memory 10.

As described above, in this embodiment, a key code is generated at a high resolution of 10 cents during sounding.However, at the start of sounding, it is generally considered that a pitch bend operation by the tremolo arm 103 or choking is not performed, and a semitone is generated. unit,
That is, a key code is obtained with a low resolution of 100 cents. In order to realize this, RUN FL in the next step C-13
The AG is checked to determine whether or not the sound has started. At the start of the sound generation, in steps C-14 to C-17, the string pressing position N having a resolution of 10 cents is converted to a string pressing position in semitone units corresponding to the fret. That is, according to K = INT (N / 10), a numerical value less than 100 cents is truncated to obtain a fret K (step C).
-14), it is determined which of the front and rear frets K and K + 1 is closer to the string pressing position N with a resolution of 10 cents (step C-1).
5) The value 10K for the closer fret K is stored in the N register (steps C-16 and C-17).

Up to this point, the string pressing position N given the measurement period IN is
It is obtained with a resolution of 10 cents during pronunciation and 100 cents at the start of pronunciation.

Therefore, in the next step C-18, the open string key code of the tuned string for the string ST is extracted from the open string key code register 12, and the value R is added to the string pressing position N in the next step C-19. The key code N representing the tuning cycle with respect to the measurement cycle is obtained.

As can be seen from the above description, in the first embodiment,
In the preset mode, each string 107 of the electronic stringed instrument is stringed at the open string fret position to check and determine the open string state of each string for tuning. Then, in the play mode, the period obtained for the string vibration state of the string 107 struck at an arbitrary position is obtained in the preset mode in order to convert the period into a key code for designating a properly tuned period. Based on the discrimination result, the measurement cycle is converted into a cycle on the string pressing position vs. cycle table memory 10,
By searching the table memory 10, the pressed string position is obtained, the key code of the open string is added to the pressed string position, and the pitch of the tone generator 13 is controlled by the key code. It is possible to always obtain a tone with a properly tuned pitch regardless of whether it is extended.

Second Embodiment Next, a second embodiment will be described. In this example,
Logarithmic processing for generating key codes is performed by direct calculation. FIG. 9 shows the overall circuit configuration of the second embodiment. Elements similar to those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted.

The calibration coefficient calculation circuit 15 corresponds to the conversion coefficient calculation circuit 8 of the first embodiment, and reads the measured open cycle stored in each of the first to sixth string open cycle registers 7a to 7f to read the reference open cycle. The ratio to the open period (calibration coefficient) is calculated, and the result is written to each of the first to sixth string calibration coefficient registers 17a to 17f. However, unlike the conversion coefficient calculation circuit 8 of the first embodiment, the calibration coefficient calculation circuit 15 operates in response to a calculation instruction from the key code conversion circuit 11A during the play mode. Also, as the reference open cycle, each string
The cycle assuming 107 is properly tuned is used. This tuned open cycle data is stored in each string 107
Is stored in the first to sixth string tuning open period registers 16 (16a to 16f). As shown in FIG. 10, the tuning release period of the first string is 3034 μsec, the second string is 4050 μsec,
The third string is 5102 μsec, the fourth string is 6811 μsec, and the fifth string is 9091
μsec, the sixth string is 12135 μsec.

The key code conversion circuit 11A of the second embodiment has a LOG (logarithmic) operation unit 11A-1, and the logarithm is directly calculated by the approximate polynomial operation in the LOG operation unit 11A-1. Therefore, in the case of the second embodiment, a logarithmic conversion table such as the string pressing position / period table memory 10 of the first embodiment is unnecessary. Key code conversion circuit 10 of second embodiment
A generates a key code at a resolution of a semitone (100 cents) when the pronunciation is disclosed, and generates a key code at a resolution of 1 cent during pronunciation. The format of this key code is selected such that one octave is 1200 (cents), one cent per cent, and the key code for note name C0 is zero. Therefore, the key code KC for the frequency F
Is given by KC = 1200log ₂ (F / K). Here, K is a constant corresponding to the frequency 16.352 Hz of the pitch name C0.

The operation will be described. In the preset mode, as in the case of the first embodiment, a string is played under the open string state of each string 107, and each open period is extracted by the pitch extraction circuit 4. The result is recorded by the processing circuit 5 in each of the first to sixth string open period registers 7a to 7f. However, no calibration coefficient is calculated at this time.

During the play mode, the operation is substantially the same as in the first embodiment, except for the key code calculation process. FIG. 11 shows details of the key code calculation process of the second embodiment.

Data TM, ST, and RUN FLUG shown in D-1 are data of the measurement period, the string number, and the sounding flag supplied from the processing circuit 5 to the key code conversion circuit 11A. In response to this, the key code conversion circuit 11A issues a calibration coefficient calculation instruction to the calibration coefficient calculation circuit 15. Therefore, as shown in step D-2, the calibration coefficient calculation circuit 15 transfers the measurement open period of the string ST (representing the state of the string determined in the preset mode) from the selected register 7a to 7f to T (M, 0). Load and step D-
As shown in FIG. 3, the tuning release cycle of the string ST is loaded from the selected register 16 into T (t, 0), and the next step D-4.
Then, the ratio T (M, 0) / T (t, 0) is calculated and loaded into the calibration coefficient register CALF (17a to 17f) of the string ST. On the other hand, the key code conversion circuit 11A loads the constant C (step D-5), calculates CALF / (TM × C), and loads the result into the Z register (step D-6). Here, TM / CALF represents a tuning cycle with respect to the measurement cycle.
In the next step D-7, the LOG operation unit 11A-1 operates and Z
Is obtained by polynomial calculation, and the result is loaded into the Y register. Next, the key code conversion circuit 11A-1 loads two logarithms (log2) into the X register (step D-).
8) The key code N = 1200 × (Y−X) is calculated with a resolution of a cent unit (D-9).

By executing the above steps D-2 to D-9, the key code N indicating the pitch of the tuned string is obtained with a resolution of one cent unit. Therefore, this key code N Given by Here, T (M, 0): the open cycle of the string measured in the open string state T (t, 0): the open cycle of the string tuned appropriately TM: measurement cycle C: constant As an example, the first Suppose that the open period of the string was measured at 3304 μsec in the preset mode. The tuning release cycle of the first string is 3034 μsec. Now, it is assumed that 1500 μsec is obtained as the measurement period of the first string in the play mode. On the other hand, the key code N of a properly tuned string has a constant C of 16.352 × 10 ^-6 (1 / C = 61154.5). Becomes That is, the pitch is 67 cents higher than the pitch name F5.

Steps D-10 to D-14 in FIG. 11 correspond to C-13 to FIG.
This is a process similar to C-17. When RUN FLAG = 0, that is, at the start of sound generation, the initial key code is changed to a semitone (10
This is a process of calculating with a resolution of 0 cents). In the case of the above example, N = 6600 (cents), and F # 5 is designated.

As described above, in the case of the second embodiment, when generating a key code, a logarithmic conversion table is not required, so that a storage capacity for the log conversion table can be saved.

<Modifications> Although the description of the embodiments has been completed above, the present invention is not limited to these embodiments, and various modifications are possible.

For example, in the above-described embodiment, the key code format for designating the pitch is given to the tone generator circuit 13 in a form in which a properly tuned cycle or frequency is logarithmically converted. Alternatively, for data compression, a key code in another format may be generated by using a table means realized by an encoder or a conversion memory. Or,
A key code (pitch designation data) that directly represents a properly tuned frequency or cycle may be used. in this case,
The logarithmic conversion process in the key code conversion circuit becomes unnecessary. For example, the key code KC for frequency expression is Can be calculated by Here, T (M, 0): the open period of the string measured at the preset time T (t, 0): the open period of the string tuned appropriately TM: the measured period of the string obtained during the play mode. Further, the tone generator circuit 13 can obtain the phase signal of the musical tone by accumulating the received frequency key code, and the key code / key code required in the above-described embodiment can be obtained.
No frequency conversion processing is required.

In the above embodiment, the open string fret position (0th fret position) is used as the string pressing position in the preset mode. However, any other predetermined position can be used as the string pressing position for determining the string state.

In the above embodiment, as shown in FIG. 12, the ratio between the length GL at which the string 107 vibrates in the open string state and the length GN at which the string 107 vibrates when the string is pressed at a predetermined fret position, and therefore, It is assumed that the ratio of the string vibration period at each length GL, GN is constant and known. However, if the position of the string support 110 or 127 is deviated from the normal position for some reason, this assumption does not hold. In this case, by measuring (sampling) the period at two or more string pressing positions in the preset mode, the deviation of the string support portions 110 and 127 can be determined, and the electronic tuning of the pitch in the play mode can be performed. . The principle will be described with reference to FIG. In FIG. 12, A
And BE represent the fulcrum of the string 107 by the string support portions 127 and 110. In the illustrated example, the fulcrum BE is shifted from the position of the normal fulcrum B. That is, the distance GL from the fulcrum A to the fulcrum B
Is the regular open string length, and the fulcrum BE is the regular fulcrum B
It is shifted by E more in the plus direction. In this case, it is assumed that the open string fret position and the 24th fret position are selected as two points when two points are sampled in the preset mode. The period measured at the open string fret position is T
The period measured at the 24th fret position is indicated by (M, 0) and is indicated by T (M, 24). Measurement open period T (M,
0) is measured by the chord length (GL + E) of the shifted open string, so that both are proportional. In addition, the 24th fret measurement period T
(M, 24) is proportional to the length of the chord from the 24th fret to the fulcrum BE. Since the string vibrates at a longer length than the normal length, the ratio T (M, 0) / T (M, M) of the open measurement period T (M, 0) and the 24th fret measurement period T (M, 24) is obtained. 24) is smaller than 4. Under such a string condition, if the relationship between an arbitrary fret N and the measurement period T (M, N) can be determined, electronic tuning is possible. From the fact that the fulcrum A is at a regular position and the regularity of the fret interval, the distance from the fulcrum A to the Nth fret is GL And the distance from the fulcrum A to the 24th fret is GL It is. The latter distance GL Is proportional to the difference between the open period T (M, 0) measured in the preset mode and the 24th fret measurement period T (M, 24), and the distance GL Is proportional to the difference between the open measurement period T (M, 0) and the measurement period T (M, N) for the fret N. Therefore, Holds. Solving this for the fret position N gives Becomes [] Indicates the ratio between the open frequency assumed for the correct chord length GL and the frequency for the fret N. If a key code is added to the open string to N, a key code similar to that of the embodiment can be obtained. If the fulcrum A on the head is also displaced, the period may be measured at three points including the open string fret position in the preset mode. For example,
Assuming that the cycle of the first fret is T (M, 1) and the cycle of the 24th fret is T (M, 24), these data and the measurement cycle T (M, N) of the Nth fret (N> 0) Between
From the regularity of fret spacing And solving for N gives Becomes Therefore, during the play mode, the measurement period T
When (M, N) is obtained, the data is compared with the open period T (M, 0) measured in the preset mode. If they match, the string pressing position N is set to 0 (= open position). The string pressing position N can be obtained by substituting the measurement period T (M, N) into the above-described N.

Certain electronic stringed instruments use a fingerboard in which fret intervals are formed at equal intervals in order to facilitate fingering operations in a high frequency range. The present invention is also applicable to this type of electronic stringed musical instrument. In this case, there is a linear (proportional) relationship between the measurement period and the string pressing position. That is,
T (M, 0), T (M, 24), T (M, N), N
Between, (T (M, 24) is equal to T if the wavelength GL is constant.
(Can be calculated from (M, 0)). Therefore, the measurement period T
In order to obtain the string pressing position N from (M, N), it is not necessary to perform logarithmic conversion of the period.

Further, the present invention can be applied not only to an electronic stringed instrument having a fingerboard having a fret like a guitar-based electronic stringed instrument, but also to an electronic stringed instrument having a fretless fingerboard such as a violin (cello, bass, etc.). . Therefore, the present invention can also be applied to an electronic bowed stringed instrument.

[Effect of the Invention] According to claim 1, when the string is vibrated at a predetermined string pressing position before the performance, the string before the performance is played based on the basic period extracted by the pitch extracting means. The stretched state is discriminated and inspected by the string state inspection means, and at the time of sounding start instruction, the fundamental period extracted by the pitch extraction means is converted into pitch-designated data tuned based on the result of the discrimination of the string state. Is performed by the initial pitch control means, and when a new fundamental cycle is extracted by the pitch extracting means during sounding, the tone is tuned in response to the new fundamental cycle based on the determination result of the string state. Since the control to convert to high specified data is performed by the after-pitch control means, it is not necessary to mechanically tune the strings, but to control the tone with the properly tuned pitch at the start of sounding. First, departure Even if the player performs an action that fluctuates the frequency of the string, such as fingering operation, choking operation, arming operation, etc., after the start of the tone, the musical tone is controlled by the tuned pitch that follows it. It is possible. With such an electronic tuning function, it is not necessary to select the type, material, thickness, etc. of all strings to be attached to an electronic stringed instrument for each string. For example, there is an advantage that strings of the same thickness can be used. Occurs.

Claims 2 and 3 show a configuration example of electronic tuning control by the string state inspection means, the initial pitch control means, and the after pitch control means. According to the second aspect, the relationship between an arbitrary depressed string position and the corresponding basic period is specified from the basic period extraction result before the performance, and this relationship is applied to the basic period data extracted during the performance. Corresponding string pressing position data is obtained, and thereafter, electronic tuning is performed by converting the string pressing position data into tuned pitch designation data. On the other hand, in the third aspect, the ratio between the basic period data obtained before the performance and the tuned basic period data is calculated, and the basic period data extracted during the performance is corrected by this ratio to tune. The electronic tuning is performed by obtaining the adjusted basic period data and then converting the tuned basic period data into the corresponding pitch designation data.

In the fourth and fifth aspects, before the performance, the extraction of the basic period is performed not at one string pressing position but at a plurality of determined string pressing positions of the string. From the result, the relationship between an arbitrary string depressed position of the string and the corresponding basic period is specified. In claim 5, any of the plurality of basic period extraction results is extracted by the pitch extracting means during the performance by the pitch extracting means. The string extending state is defined by specifying the relationship between the basic period data and the tuned basic period data. Therefore, it is possible to more accurately know the string tension state, and it is possible to perform highly reliable electronic tuning. It is also effective when the fulcrum of the string is deviated from the normal position.

According to the sixth aspect, at the time of sounding start instruction, pitch designation data tuned at the first resolution is generated by the initial pitch control means, and after the sounding start instruction, the after-pitch control means is higher than the first resolution. Since pitch-designated data tuned at the second resolution is generated, pitch control that follows minute changes in the vibration frequency of a string caused by a choking operation, an arming operation, or the like performed after a string is struck can be performed. .

Claim 7 shows that the pitch determining apparatus is used in an electronic stringed instrument including a tone generating means for generating a tone with a tuned pitch. Therefore, it is not always necessary for the electronic stringed musical instrument itself to incorporate the tone generating means in the pitch determining apparatus of the other claims.

Claim 8 shows that the pitch determining apparatus is used in an electronic stringed instrument including a tremolo operator that causes fluctuation in basic cycle data extracted by the pitch extracting means. Therefore, the pitch can be controlled in accordance with the operation on the tremolo operator.

The ninth, tenth, eleventh, and twelfth aspects show examples of string pressing positions selected to check the state of string extension. For example,
The open string fret position (Claim 9), or the open string fret position and at least one depressed string position at a predetermined distance from the open string fret position (Claim 10), or non-uniformity on the fingerboard according to 12 equal temperament At least one of a number of fret positions defined at intervals (Claim 11) and at least one of fret positions defined at equal intervals on the fingerboard (Claim 11)
12) is the string pressing position for checking the string tension state.

Claim 13 shows that the pitch determination device is used in an electronic stringed musical instrument having a plurality of strings. in this case,
Electronic tuning is performed for each of the plurality of strings.

Claim 14 shows an embodiment of a plurality of strings. In this embodiment, a single continuous string material is bent at a plurality of locations to form a plurality of strings.

Claim 15 shows a configuration example of the string vibration detecting means. An electromagnetic pickup device, an optical pickup device, or a piezoelectric element pickup device can be used as the string vibration detecting means.

Claim 16 exemplifies the structure of a string when an electromagnetic pickup device is used as the string vibration detecting means. The base material of the string is a non-magnetic string member, and a cylindrical magnetic member is formed at a position corresponding to the electromagnetic pickup device.

In the configuration of claim 17, as the pitch designation data, for data compression, using a key code that represents the pitch with a predetermined conversion function of the cycle, provided conversion table means for storing the data of the conversion function, Since the key code is generated by referring to the conversion table means in each of the initial and after pitch control means, data transfer to the means using the key code (tone generating means) is facilitated and the speed is increased. There are advantages.

On the other hand, in the configuration of claim 18, a key code expressing the pitch by a predetermined logarithmic function of the period is used as the pitch specifying data, and the key code tuned by the initial and after pitch control means is directly used. Therefore, there is an advantage that logarithmic conversion table means is not required.

Further, in the configuration of claim 19, since the key code for expressing the pitch in frequency is used as the pitch designation data, it is not necessary to perform the key code / frequency conversion in the phase generating section on the tone generating means side. There is an advantage that the configuration of the generating means can be simplified.

[Brief description of the drawings]

FIG. 1 is an external view of an electronic stringed instrument according to an embodiment of the present invention,
FIG. 2 is a diagram showing the overall circuit configuration of the first embodiment, FIG. 3 is a diagram showing the contents of a string pressing position versus period table memory in FIG. 2, and FIG.
Diagram showing the contents of 12 and the data format of the key code,
FIG. 5 is a flowchart showing the operation of the conversion coefficient calculating circuit 8 of FIG. 2, FIG. 6 is a flowchart showing the operation of the first embodiment during the play mode, and FIG. 7 is a string used in the description of FIG. Vibration waveform and music sound waveform time chart,
FIG. 8 is a flowchart showing the operation of the key code conversion circuit in FIG. 2, FIG. 9 is a diagram showing the overall circuit configuration of the second embodiment, and FIG. 10 is a diagram showing the contents of the tuning release period register 16 in FIG. FIG. 11 is a flowchart showing the operation of the calibration coefficient calculation circuit and the key code conversion circuit in FIG. 9;
FIG. 12 relates to a modification and is a diagram used to explain electronic tuning for a string having no regular string length. 4 Pitch extraction circuit, 5 Processing circuit, 6 Mode switch, 7a to 7f Measurement open cycle register, 8
… Conversion coefficient calculation circuit, 9a to 9f …… Conversion coefficient register, 10
…… String pressing position vs. cycle table memory, 11 …… Key code conversion circuit, 12 …… Open string key code register, 15 …… Calibration coefficient calculation circuit, 16 …… Tuning open cycle register, 17a-1
7f: calibration coefficient register; 11A: key code conversion circuit; 11A-1: logarithmic operation unit.

Claims (19)

(57) [Claims] 1. A finger board, at least one string stretched on the finger board, string vibration detecting means for detecting vibration of the string, and a string detected by the string vibration detecting means. Pitch extraction means for extracting the basic period data from the vibration, and a sounding start instruction for instructing a sounding start of a musical sound when the vibration of the string detected by the string vibration detecting means is equal to or higher than a predetermined vibration level. Means for determining the pitch used in an electronic stringed musical instrument, comprising: when the string is vibrated at a predetermined string-pressing position prior to playing, based on the basic period extracted by the pitch extracting means. A string state inspection means for discriminating and inspecting a string tension state; and a sound extraction means which operates during performance and which is extracted by the pitch extraction means when a sound generation start instruction is issued by the sound generation start instruction means. Initial pitch control means for converting the basic cycle data, which has been tuned, into corresponding pitch designation data tuned in accordance with the string stretching state determined by the string state inspection means; In response to the fact that new fundamental period data is extracted by the pitch extracting unit after the sounding start instruction is issued by the sounding start instructing unit, the new fundamental period data is sent to the string state inspection unit. An after-pitch control means for controlling to convert to tuned corresponding pitch designation data in accordance with the determined stretched state of the string. 2. The pitch determining apparatus according to claim 1, wherein said string state inspection means specifies a relationship between an arbitrary pressed position of said string and a basic period corresponding thereto, and based on said specified relationship. The initial pitch control means and the after-pitch control means, the basic pitch data extracted by the pitch extraction means, According to the relationship identified by
First converting means for converting the corresponding string pressing position data to string pressing position data; and second converting means for converting the string pressing position data from the first converting means to tuned corresponding pitch designation data. Pitch determining device. 3. The pitch determining apparatus according to claim 1, wherein said string state detecting means includes: when said string is vibrated at said predetermined string pressing position, said basic period data extracted by said pitch extracting means; The initial pitch control means and the after-pitch control means calculate a ratio between the tuned basic cycle data at the string-pressing position and the basic pitch data extracted by the pitch extraction means. A tuning period deriving unit that derives tuned basic period data according to the corrected basic period data according to the ratio calculated by the ratio calculating unit; anda basic period data tuned by the tuning period deriving unit. Conversion means for converting the data into corresponding pitch designation data. 4. The pitch determining apparatus according to claim 1, wherein the string state inspecting means is configured to calculate the string condition from the basic period data extracted by the pitch extracting means for each of a plurality of different predetermined string pressing positions of the string. Pitch determining means for specifying a relationship between an arbitrary string pressing position of a string and a corresponding basic period, and based on the specified relationship, there is provided a relationship defining means for defining the string stretching state. apparatus. 5. The pitch determining apparatus according to claim 1, wherein the string state inspection means performs a performance based on basic period data extracted by the pitch extraction means for each of a plurality of different predetermined string pressing positions of the string. During this process, the relationship between arbitrary basic period data to be extracted by the pitch extracting means and the tuned basic period data is specified, and based on the specified relation, the string extending state is determined. A pitch determining device comprising a relationship defining means for defining. 6. The pitch determining device according to claim 1, wherein when a sound generation start instruction is issued by said sound generation start instruction means, said basic pitch extracted by said pitch extraction means is transmitted to said initial pitch control means. It is instructed to convert the cycle data into the corresponding tuned pitch designation data at the first resolution, and after the tone generation start instruction means issues a tone generation start instruction, the after tone pitch control means is instructed. On the other hand, a resolution selection instruction for instructing to convert the fundamental period data newly extracted by the pitch extraction means into tuned corresponding pitch designation data at a second resolution higher than the first resolution. A pitch determining device comprising means. 7. The pitch determining apparatus according to claim 1, further comprising a tone generating means for generating a tone having a corresponding pitch in accordance with the pitch designation data converted and controlled by said pitch control means. Pitch determining device. 8. The pitch determining apparatus according to claim 1, further comprising a tremolo operator for changing a state in which the strings are stretched in accordance with an operation during performance. 9. A pitch determining apparatus according to claim 1, wherein said predetermined string pressing position is an open string fret position of said string. 10. The pitch determining apparatus according to claim 1, wherein
The pitch determining device according to claim 1, wherein the predetermined string pressing position is a plurality of string pressing positions including an open string fret position of the string and at least one string pressing position separated by a predetermined distance from the open string fret position. 11. A pitch determining apparatus according to claim 1,
The pitch determining apparatus according to claim 1, wherein the predetermined string pressing position is at least one string pressing position among a plurality of fret positions defined at unequal intervals on the fingerboard according to 12 equal temperament. 12. A pitch determining apparatus according to claim 1,
The pitch determining device according to claim 1, wherein the predetermined string pressing position is at least one string pressing position among a plurality of fret positions defined at equal intervals on the finger board. 13. A pitch determining apparatus according to claim 1,
The pitch determining device according to claim 1, wherein the strings include a plurality of strings. 14. A pitch determining apparatus according to claim 13,
The pitch determining device according to claim 1, wherein the plurality of strings are formed by bending a single continuous string at a plurality of locations to form a plurality of string portions. 15. The pitch determining apparatus according to claim 1, wherein
The pitch determining device is characterized in that the string vibration detecting means is selectively used among an electromagnetic pickup device, an optical pickup device, and a piezoelectric element pickup device. 16. A pitch determining apparatus according to claim 1, wherein:
The string vibration detecting means includes an electromagnetic pickup device, and the string is provided at a portion of the nonmagnetic string member fixedly supported at both ends, and at a portion of the nonmagnetic string member facing the electromagnetic pickup device. A pitch determining device comprising a cylindrical magnetic member. 17. The pitch determining apparatus according to claim 1, wherein each of the initial pitch control means and the after-pitch control means sets a pitch in a cycle to compress the pitch designation data. Key code generation means for generating a key code expressed by a predetermined conversion function as the pitch designation data, the key code generation means comprising: a conversion table means for storing data of the predetermined conversion function; Means for generating a tuned key code by referring to the data of the conversion table means from the basic period data extracted by the pitch extraction means and the string extension state determined by the string state inspection means. A pitch determining device comprising: 18. The pitch determining apparatus according to claim 1, wherein each of said initial pitch control means and said after-pitch control means includes a key code for expressing a pitch by a predetermined logarithmic function of a period. Key code generating means for generating as pitch designation data, wherein the key code generating means is configured to calculate the basic period data extracted by the pitch extracting means and the string extending state determined by the string state inspecting means. And a key code calculating means for directly calculating a tuned key code. 19. The pitch determining apparatus according to claim 1, wherein each of the initial pitch control means and the after pitch control means uses a key code expressing a pitch in frequency as the pitch designation data. Key code generating means for generating the key code, wherein the key code generating means is tuned from the basic period data extracted by the pitch extracting means and the string extension state determined by the string state inspecting means. A means for generating a key code representing the frequency of the pitch.