KR840001161B1 - Tuning a key - Google Patents

Abstract

A tuning device for a piano consists of an input part(A); a displayer (B); a multiplier/ counter(C), which multiplies the input frequency by 100-1000 times and counts the fre- quency down to three decimal places; a standard frequency generator, which generates the same frequencies as the 88Keys of a piano; an error detector (E), which compares the input signal with the output of (E) and sounds off when an error is detected; a displayer (F), which stores and shows each frequency corresponding to each piano key; and a vibrator (G) that vibrates the string being tuned continuously to allow the device to be used efficiently.

Description

Piano tuner

1 is a schematic diagram of the components of the present invention.

2 is a detailed schematic diagram illustrating a specific embodiment of the apparatus of the present invention.

The present invention relates to a novel apparatus for tuning the sound emanating from a piano. In more detail, the present invention aims to effectively tune the piano's sound using an electronic measuring device.

Since the tuning of the conventional piano has been mainly dependent on the human ear, in this case, there is a difference in the tuning effect according to the skill of the tuner, and even in the case of a skilled tuner, there is a limit in the precision or accuracy, so that a satisfactory effect can be obtained. none. (The accuracy required for the tuning of the current piano is at least two digits below the decimal point in the low range, but it is difficult to expect such accuracy when using the human ear.) Recently, the following two measurement methods or devices are It is also used in piano tuning.

First method: “Strobe strobe” which sets the interval of the interval on the rotating disk, rotates it at a constant speed, and then amplifies the sound of the instrument and projects the lamp as the amplified frequency on the driving rotating disk to observe the synchronization visually. strobe scope).

Second: The oscillation frequency of one crystal oscillator is divided into appropriate frequency dividers and 12 sounds are obtained.

However, the above two measurement methods have the following problems, which have not been effectively put to practical use yet.

(1) Problems with the first method:

A. In time, the synchronization point is not clear, and at least 12 bands are narrowly arranged in a disc, which causes confusion in observation.

N. Since the frequency of 12 sounds is not composed of integers, severe errors occur by removing and arranging dot or line number arrays within one circumference less than integers, which is worse than listening and adjusting by ear. It may also occur. (In general, an error of 0.5% or more may occur, but the error range required by the instrument is 0.1%.)

C. The error due to the rotational nonuniformity of the motor driving the disc can be added to the error of b so that the degree of the error can be further increased.

D. In the case of attenuated vibration instruments such as pianos, it is difficult to tune because of the short observation time.

M. Due to the high frequency mixed with the fundamental wave, in some cases, it is easy to cause a mistake by synchronizing with other notes or making the synchronization point unclear.

(2) Problems of the second method:

A. Although there is a progressive advantage such that the error is smaller than the above equation (1), in this case, too, there is an error due to the integer distribution, and especially in the low range, the observation error coming from the phase difference interval is severe and may be worse than returning home. Can be.

N. The observation time is very short and difficult to tune because a large input signal is required.

C. It cannot be used outside the quiet place.

D. Since you can't tune the whole range of the instrument, you'll have to train your ears, because you'll only have to tune the center first. (Only developed as an assistant of the existing tuner)

The present invention has provided a piano tuning device and an effective tuning method using the same device having the following advantages that can solve the conventional problems as described above.

A. It can be used without disturbing the measurement even in the noisy places.

N. Frequency accuracy is equal to Xtal's basic accuracy (0.002%).

C. It constantly accepts inputs without any keystrokes, so you can easily check the frequency in a stable state. You only need to adjust the tuning hammer, and you don't have to keep tapping the keys. Therefore, the tuning speed can be much faster.

D. No skill is required, so little time is required for pre-training, so anyone can use it in a short time.

M. The quantitative display of the frequency eliminates trouble between the coordinator and the client.

Iii. It can be used as a basic device in robotization for quantitative processing of production plants.

G. Tuning is possible with any reference frequency as standard, and can be tuned to quantitatively adjust the frequency correction, especially for the auditory function in the high region.

The main components of the present invention, their operation, and effects will be described schematically with reference to FIG.

(P) Pick-up: Sends only the sound from the piano to the input processing unit (A) and removes external noise. This pickup is detected using a known magnetic pickup or a condenser pickup using the capacitance between the wires of the piano and the pick-up pole, where the pickup is released by releasing the action mechanism of the piano, It can be installed in the center to make it easy to bring pickup to any string.

(A) Input processing unit: It receives the electric signal through the vibration of the strings of the piano to remove various disturbances mixed in the signal and makes the signal pure and of sufficient size. In Fig. 2, the input processing unit A is composed of a pickup 1, an amplifier 2, a low pass filter 3, an logarithmic amplifier 4, a waveform shaping circuit and the like.

(B) Waveform Observation Unit: This part enables the user to directly see the waveform made to observe through (A), and has the same function as the well-known "syncro scope". Through this section, it is possible to discriminate the abnormal state of the piano, which cannot be known only by frequency observation, for example, the failure of the strings, the rupture of the sound board, the abnormal resonance, and the sound quality. In FIG. 2, the corrugation observation portion B is composed of a synchroscope 28 or the like.

(C) Frequency multiplication and counting unit: Multiply the basic frequency received through (A) by 100 to 1,000 times to increase it, and then use the counter to accurately read up to three digits below the decimal point. It is possible to fall within the required tolerances. In FIG. 2, the frequency multiplying and counting unit C includes a phase comparator 8, an integrator 9, a voltage controlled oscillator 10, a 1/1000 divider 11, a counter 12, and a counter display 13 )

(D) Standard frequency generator, which produces the basic 88 frequencies required by the piano, which can be heard directly through the loudspeakers, or the sound and sound of the instrument. You can do it. 2, the standard frequency generator D includes a standard oscillator 17, a basic sound generator 18, a divider 19, and the like.

(E) Error detection and error display part: by comparing the signal coming from the instrument with the signal from the standard frequency of (D), the presence and the amount of error can be heard as a specific signal sound together with the display lamp. Without listening to every indicator attached to the device, you can listen to a specific signal with your ears and make your eyes easier to adjust while observing the contents of the piano. In FIG. 2, the error detection and error display unit E includes a phase comparator 20, a lamp 21, a modulator 22, an amplifier 23, a speaker 24, a frequency comparator 25, and an L lamp 26. And an H lamp 27 or the like.

(F) Standard frequency display part: A part that memorizes the frequencies of each keyboard (88 pieces) of the piano. It indicates the number of frequencies to be adjusted accordingly. Since the frequencies are slightly different, this section displays four strings of 88 sounds = 352 frequencies and the names of the sounds. In Fig. 2, the standard frequency display section F is composed of a standard frequency memory 54, a frequency coefficient display device 15, a memory drive circuit 16, and the like.

(G) Vibration section: The piano string vibrates once and then continues to vibrate without attenuation. It amplifies the input signal and sends mechanical vibration back to the string. In FIG. 2, the vibrator G is connected to the integrator 29, the large parabolic 30, the gite 31, the analog switch 32, the amplifier 6, and the resonant speaker or magnet 7, and the like. Consists of.

Specific embodiments and effects of the present invention will be described in detail with reference to the embodiment of FIG. 2.

Example: After amplifying an electric signal obtained from a pickup 1 into a signal having a sufficient magnitude (2), harmonics contained in a signal component are filtered by a low pass filter (3). At this time, since the low side does not interfere with the measurement, the filter 3 is filtered to have attenuation amount of about 20 decibels per dB using the filter 3. Since the signal passed through the filter 3 has a large amplitude fluctuation in the signal waveform, the signal has a certain amplitude signal through the logarithmic amplifier 4 and is then put into a square trigger (5). Make it.

On the other hand, in order to resonate the string from the log amplifier 4 through the amplifier 6, the resonance speaker or the magnet 7 is operated to keep the string continuously vibrating. The square wave produced by the waveform shaping circuit 5 is input to the phase comparator 8.

At this time, the voltage controlled oscillator 10 sets the time constant as about 1,000 times the input signal frequency of the independent frequency near the incoming frequency, which must be within a condition within a so-called capture range. When the frequency generated in the voltage sine oscillator 10 passes through the 1/1000 divider 11, the frequency becomes similar to the input frequency. The difference between the two frequencies is compared in the phase comparator 8 to output a signal proportional to the phase difference.

This output is integrated into the DC voltage in the integrator 9 and applied to the voltage controlled oscillator 10 to change the frequency frequently to follow the frequency from the waveform correcting circuit 5. Therefore, once the frequency of the voltage controlled oscillator 10 is locked, it is always followed by a frequency 1000 times higher than the input frequency.

This frequency is input to the counter 12 to read the frequency through the counting display device 13. In this case, for example, when 100 ms is subscribing, the counter 12 counts 100,000, enabling observation up to three digits after the decimal point.

On the other hand, since there are 88 notes on the piano, it is not possible to memorize all the frequencies. Therefore, the frequency table is stored in the standard frequency memory 14, and the input frequency and the frequency are displayed when the manipulation of the sound is performed. For comparison, they are driven by the memory driver circuit 16.

However, having to read the frequency at all times will make the tuning party tired, so the following arrangements are provided to facilitate identification by simply interrupting the ramp or modulated sound until near access.

After inputting the signal generated from the standard frequency oscillator 17 to the basic sound generator 18, the standard sound of 12 scales is obtained, and each octave is obtained through the divider 19 so that all 99 sounds can be drawn. The sound selected as the current matching and declining sound is put into the phase comparator 20 together with the input signal from the waveform correcting circuit 5 to obtain a phase difference signal, thereby operating the lamp 21. Then, since the lamp 21 is a gum buck as a difference with the input frequency, it can be easily visually discriminated.

On the other hand, the input signal from the logarithmic amplifier 4 is compared with the divider signal, and modulated by the modulator 22 to operate the speaker 24 through the amplifier 23, so that the sound as the ear can be seen without continuing to look at the device. The adjustment was made. On the other hand, in the case of approaching the standard sound very close, the standard sound through the frequency divider 19 and the input from the waveform shaping circuit 5 in consideration of when the current input sound is higher or lower than the standard sound is not easily distinguished. The L lamp 26 is turned on when the signal and the frequency comparator 25 is low, and the H lamp 27 is turned on when the signal and the frequency comparator 25 are high. However, since the display through the phase difference described above after the standard oscillator 17 involves an error (0.05%) of the synthesizer, the final confirmation is accurate through the counting display device 13. The synchronizer 28 is installed to directly observe the instrument's tone or string or abnormality through a waveform. In particular, when the continuous electrical signal such as an electron org can be directly extracted, it is tuned into a Lissajou type. The adjustment is particularly easy.

And sometimes, when the initial input signal is insufficient and there is no resonance, the following circuit operates. When the signal of the pickup 1 is weak, the low signal of the amplifier 2 turns on the comparator 30 via the integrator 29.

Then, the standard sound of the synthesizer (synthesizer) hanging on the gate 31 is input to the amplifier 6 to force the string to vibrate through the resonance speaker or the magnet 7. At this time, since the output of the comparator 30 closes the analog switch 32, the input signal is blocked. However, even if the string vibrates a little even by forced vibration, since the comparator 30 is turned off, the analog switch 32 is opened and the gate 31 is closed so that the input signal enters and eventually enters the resonance region. The power supply unit 31 is connected to electrically operate the above-described parts. Referring to the effects of the present invention configured as described above are as follows.

When the pickup (P) of the present invention is moved to the string of the piano which is currently tuned and deteriorated, the piano string is always vibrating, so the vibration sound is amplified (2) and filtered (3) in the input processing unit (A), and the pure water amplified. On the other hand, while the sound waves of the piano strings repeat the process of vibrating the vibrating unit G and transmitting the amplified sound waves to the piano strings on the one hand, a part of the pure sound waves of the amplified piano strings The sound wave, which is sent to the frequency multiplication and counting unit C, in which the coefficient 13 is sent together with the standard sound wave sent from the standard frequency generating unit D, enters the error detection and error display unit E simultaneously.

Here, in (E), the error of the positive sound is tuned by sending a visual signal to one of the lamps 21, 26 and 27, and at the same time sending an audio signal from the speaker 24 to the other. Enable visual and / or audio performance.

In this case, the L lamp 26 flashes when the difference between the positive sound waves entering here (E) is lower than the standard sound waves, and the H lamp 27 flashes when the sound wave is higher than the standard sound waves, and the lamp 21 flashes when the positive waves match by tuning. It is only turned on, and when the sound waves are different, the sound comes from the speaker 24, and the sound is not produced when the tone is matched. Therefore, according to the device of the present invention

A. Only the sound waves emitted from the piano strings are filtered and tuned, so they can be used without disturbing the measurement even in the noisy places b. Since the tuning is made to match the standard frequency, the frequency accuracy can be matched with the basic accuracy of Xtal (0.002%), so precise tuning is possible. The vibration part acts continuously without inputting, so the input can be continuously checked so that the frequency can be easily checked in a stable state. Only the tuning hammer can be adjusted and thus the tuning speed can be accelerated. Anyone can use it in a short time because no skill is required. Since the frequency is quantitatively displayed, it is convenient because there is no trouble between the coordinator and the client (tuner) as before. It can be used as a basic device in the robotization for the quantitative treatment of production plants, g. Tuning at any reference frequency can be a standard feature, and it can also be characterized by the ability to tune quantitatively to tune the frequency, especially in high-area auditory functions.

Claims (1)

The input processing unit A receives the vibration of the strings of the piano as an electrical signal through the pickup, and removes various disturbance components mixed into the signal, and makes the signal pure and sufficient in size, and observed through the input processing unit A. Waveform observation section (B) that allows you to visually see the waveforms that are good to make, and multiply by increasing the fundamental frequency received through (A) by 100 to 1000 times, and then use the counter to read up to three decimal places. The frequency multiplication and counting unit (C) and the standard frequency generator (D) for producing the basic 88 frequencies required by the piano, and the signal from the instrument and the signal from the standard frequency generated in the (D) Error detection and error display unit (E) to hear the presence and amount of errors together with a display lamp and a specific signal tone, and each keyboard of the piano (8) And a standard frequency display section (F) storing eight frequencies, and a vibration section (G) which allows the string string to vibrate without attenuation once the piano string vibrates once.

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