JPH0136237Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a tuning frequency measuring device used, for example, in tuning a musical instrument, and aims to propose a tuning frequency measuring device whose display can also be used as a clock.

<Background of the invention> The present applicant has already commercialized a number of frequency measuring instruments for tuning. As shown in FIG. 1, the tuning frequency measuring device currently on the market has a pointer-shaped indicator 102 attached to a case 101.
It is designed to display the amount of frequency deviation of the sound of the instrument you are trying to tune. Knob 103
is for operating a switch that changes the name of the note to be tuned, and the knobs 103 are surrounded by A, A#, B, C, C#, D, D#, E, F,
Twelve pitch name symbols F#, G, and G# are displayed, and depending on the switching position of the knob 103, which pitch name is currently being tuned is displayed.

The tuning frequency measuring instrument shown in FIG. 1 requires an operation to previously set the name of the pitch to be tuned using the knob 103. Furthermore, since it is unthinkable to use it for purposes other than tuning, it is used every day by, for example, orchestras whose job is to perform, but it is rarely used by general students, making it uneconomical.

<Purpose of the invention> This invention aims to provide a tuning frequency measuring instrument that can also be used as a clock.

Therefore, according to this invention, since it can be used as a watch during normal times, the product value can be improved and a convenient product can be provided.

<Summary of the invention> This invention has musical tones A, A#, B, C, C#, D,
Focusing on the fact that it is made up of 12 sounds: D#, E, F, F#, G, and G#, this display arranges the pitch name symbols of these 12 sounds to correspond to the time display from 1 to 12 on a clock. When using the instrument as a frequency measuring instrument for tuning, the display displays the time, and when used as a frequency measuring instrument for tuning, for example, the hour hand of the clock indicates the pitch name of the musical tone input, and the minute hand of the clock indicates the name of the musical note input. The device is configured to display the amount of frequency deviation of the sound.

<Example of the invention> An example of the invention is shown below in Figure 2. Second
The figure shows an example of a display used in the frequency measuring device of this invention. In this invention, the time display of the clock
12, 1, 2, 3, . . . Pitch name symbols A to G# representing pitch names are written at the positions corresponding to 11, and means for representing long and short hands are provided inside them. This example shows a case where analog display is performed using a liquid crystal display format. That is, electrode groups 201 and 202, for example, 60 electrodes, are provided along the circumference marked with pitch names A to G#. It is assumed that the outer electrode group 201 performs a display corresponding to a long hand. It is also assumed that the inner electrode group 202 performs a display corresponding to a short hand. When operating as a clock, for example, a clock is displayed in the center. Therefore, in this state, for example, the positions of the electrodes displayed in black in the outer electrode group 201 display the minutes of the time. Further, the position of the electrode displayed in black in the inner electrode group 202 indicates the time.

On the other hand, when operating as a tuning frequency measuring device, tuner is displayed in the center, indicating that it is operating as a tuning frequency measuring device. When operating as a frequency measuring device for tuning, a microphone captures a musical tone, the frequency of that tone is measured by a circuit described later, and it is determined which frequency corresponds to the frequency of the note name. , the results of the determination are displayed by the short hand electrode group 202.
The electrode group 201 for the long hand displays how much the frequency of the input sound deviates from the standard frequency of the note name specified by the electrode group 202 for the short hand. Generally, the ratio between the frequency of the input musical tone signal and the standard frequency of each note name is determined, and when the ratio is 1, zero cent is indicated. In the example in Figure 2, the pitch name symbol A written at the position corresponding to 12 o'clock on the clock is set as zero cents, and around this position +50 cents and -
This shows the case where instructions for 50 cents are given.
In other words, the 3 o'clock and 9 o'clock positions on the clock represent +50 and -50 cent positions.

FIG. 3 shows a block diagram of a device that implements the display method shown in FIG. 2. In the figure, 301 is a microphone, 30
2 is a fundamental wave extraction circuit. Fundamental wave extraction circuit 30
2 will explain its operation in detail with reference to FIG.
Here, it is simply defined as extracting the fundamental wave from various musical instrument sounds and outputting a signal with a period determined by the fundamental wave.

The signal output from the fundamental wave extraction circuit 302 is input to the microcomputer 303. As is well known, the microcomputer 303 includes, for example,
CPU304, RAM305, ROM306,
It can be configured by an input port 307 and an output port 308. CPU304 is ROM30
6 and measures the period of the signal input to the input port 307. When the period is measured, the reciprocal of the period is calculated and the frequency is calculated. Based on the obtained frequency and a frequency table stored in a part of the ROM 305, for example, it is determined which note name the input note corresponds to. This determination result is outputted from the output port 308 to, for example, a decoder 309, and the decoder 309 decodes which electrode in the electrode group 202 that constitutes the short hand is to be given the signal, and then the signal is sent to the electrode of the display 312 through the display drive circuit 311. For example, a display command of L logic is given to one of the group 202.

On the other hand, the ratio of the frequency stored in the ROM 306 and the frequency of the input signal is calculated, and the calculation result is output from the output port 308 to the second decoder 313, which corresponds to the long hand of the display 312 through the display drive circuit 314. is applied to the electrode group 201.

In other words, when the ratio _1/2 between frequency ₁ of the input signal and frequency ₂ of the corresponding note name is ₁ , 0 cent is indicated. When _1/2 is _1/2 > 1 _, the cent value on the plus side is indicated _{. 1/2} When <1 _, indicate the cent value on the negative side. For example, as shown in Figure 2, when the hour hand points to A# and the long hand points to A, the input sound is A#, and the frequency of that sound exactly matches the frequency of A#. is displayed.

In addition, in FIG. 3, 315 indicates a mode changeover switch. By switching the mode selector switch 315, the microcomputer 303 is switched between operating as the above-mentioned tuning frequency measuring device, operating as a clock, operating as a stopwatch, and operating as a metronome, tempo meter, etc. be able to. When operating as a metronome, the indicated position of the long hand display electrode group 201 moves back and forth between, for example, B-A-G according to the time signature set in the setting device 316, thereby performing metronome display.

When operated as a tempo meter, the period of the acoustic signal captured by the microphone 301 is converted into a frequency value, and the frequency value is displayed, for example, on the numerical display section 203 shown in the center of the display shown in FIG. This value is used to display the tempo.

In addition, when operated as a tuning frequency measuring instrument, the standard tuning frequencies are 399Hz, 440Hz, and 441Hz.
It is necessary to select which Hz to set. This set frequency can be displayed on the numerical display section 203.

<Description of Fundamental Wave Extraction Circuit 302> FIG. 4 shows an example of the fundamental wave extraction circuit 302.
The fundamental wave extraction circuit 302 shown here is
This is one example proposed by the applicant in No. 60775.

In FIG. 4, reference numeral 401 indicates an input terminal, to which a musical tone signal or other signal is supplied. For example, a musical tone signal supplied to this input terminal 401 is amplified to a desired level by an amplifier 402 as necessary, and then supplied to a fundamental period extraction circuit 403.

The fundamental period extraction circuit 403 includes a so-called zero cross detection circuit 404 that detects when the input musical tone signal crosses a zero point or a certain level near zero, a positive or negative peak detection circuit 405, and these detection circuits 404 and 405. The flip-flop 406 is set and reset by the detection output of the flip-flop 406. Zero cross detection circuit 4
In this example, reference numeral 05 indicates a case in which an operational amplifier is used, and the amplified output of the amplifier 402 is applied to, for example, a non-inverting input terminal of the operational amplifier, and an inverting input terminal is connected to a common potential point in this example. Therefore, in this example, the polarity of the output of the operational amplifier is inverted every time the input musical tone signal crosses the zero point. The polarity of this zero-cross detection signal is inverted by an inverter 407 as required, and the signal is supplied to one input terminal of a flip-flop 406, for example, a reset terminal R.

On the other hand, in this example, the positive or negative peak detection circuit 405 is configured to detect a negative peak. That is, diode 408 and capacitor 40
9 constitute a peak hold circuit, this peak hold circuit holds a negative peak voltage, and the hold voltage is applied to, for example, a non-inverting input terminal of the operational amplifier 410. The amplified output of amplifier 402 is directly supplied to the inverting input terminal of operational amplifier 410 . A resistor 411 is connected in parallel to the capacitor 409 constituting the peak hold circuit to discharge the hold voltage charged in the capacitor 409 at a relatively slow rate, and a transistor 412 is also connected in parallel. This transistor 412 is instantaneously turned on by the differential pulse every time the flip-flop 406 is inverted by the zero-cross detection signal, so that the peak hold voltage is instantaneously lowered by a certain level. Capacitor 413 and resistor 41
4 and 415 constitute a differential circuit for this purpose, and a diode 416 represents a protection diode for the transistor 412. In this way, the negative peak detection circuit 4
By configuring 05, the output of the operational amplifier 410 is inverted each time the input musical tone signal approaches the negative peak value of the previous cycle, so that a detection pulse is obtained at each negative peak point. This detection pulse is supplied to the other input terminal of the flip-flop 406, for example, the set terminal S, with the polarity inverted through the inverter 417 as required.

Therefore, according to the above-described configuration, a musical tone signal Sa having a waveform as shown in FIG. 5A, for example, is input to the input terminal 401.
is input, zero cross detection circuit 404
The zero cross detection signal as shown in Figure B
Sb is output. According to this zero-cross detection signal Sb, various cycles such as cycles T ₁ , T ₂ , T ₃ , and T ₄ are possible as shown in the figure. Therefore, it is not possible to specify the fundamental period of the input musical tone signal Sa only using this zero-cross detection signal.

On the other hand, an input musical tone signal is output from the operational amplifier 410 of the negative peak detection circuit 405 as shown in FIG.
A pulse Sc is obtained each time Sa reaches a negative peak. Assuming that the flip-flop 406 is triggered by the falling edge of the input pulse in this example, the polarity of the zero-crossing detection signal Sb and the negative peak detection signal Sc is inverted by the inverters 407 and 417 and applied to the flip-flop 406. Diagram B
The flip-flop 406 is triggered by the rise of the detection signals Sb and Sc shown at and C. Therefore, if the flip-flop 406 is set by the rise of the negative peak detection signal Sc, the flip-flop 406 is reset by the next rise of the zero-cross detection signal Sb. flipflop 4
06 is once reset, the flip-flop 406 will not be inverted even if the zero-crossing detection signal Sb rises thereafter. Yotte Flip Flop 4
06, a pulse Sd as shown in FIG. 5D is obtained. It will be understood that the period T ₁ ' of this output pulse Sd coincides with the fundamental period T ₁ of the input musical tone signal Sa, so that the output of the flip-flop has a period equal to the fundamental period T ₁ of the input musical tone signal Sa.

FIG. 6 shows an example of another display method of this invention.
In this example, the pitch name symbols A to G# are arranged in a ring, and when a liquid crystal display electrode is provided in the pitch name symbol section to operate as a frequency measuring instrument for tuning, the pitch name of the input musical tone can be displayed, for example, as shown in the figure. A case is shown in which the sound is displayed in white and the shift in the frequency of the sound is displayed by a group of pointer electrodes 601.

When operating as a clock, the minute hand is displayed by the electrode group 601, and the hours are displayed by the hour hand by displaying the pitch name symbol in white, for example.

As explained above, according to this invention, by combining a clock and a tuning frequency measuring device, it can be used normally as a clock, so it can be used without waste.
We can provide tuning frequency measuring instruments with high commercial value. In addition, since the time display uses the display part of the tuning frequency measuring device, it can be manufactured at low cost. Furthermore, even if it can be used as a clock, frequency measuring device for tuning, metronome, tempo meter, etc., all of these are handled by the microcomputer 303.
It can be configured with a simple configuration and can have a wide variety of functions. The microcomputer 303 is currently a single-chip type.
Since it is commercially available as an IC, the device according to this invention can be incorporated into various types of timepieces such as wristwatches, table clocks, and pendant types.

[Brief explanation of drawings]

Fig. 1 is a perspective view for explaining a conventional tuning frequency measuring instrument, Fig. 2 is a plan view showing an embodiment of a display device used in this invention, and Fig. 3 is an illustration of an embodiment of this invention. The block diagram shown in Figure 4 is a connection diagram for explaining the fundamental wave extraction circuit used in this invention.
Figure 5 is a waveform diagram to explain its operation, and Figure 6 is a waveform diagram to explain its operation.
The figure is a front view showing another example of the display device used in this invention. A, A#, B,...G#... pitch name symbol, 201...
... Electrode group for long hand display, 202 ... Electrode group for short hand display, 301 ... Microphone, 302 ... Fundamental wave extraction circuit, 303 ... Microcomputer, 3
12...Indicator.

Claims (1)

[Scope of Claim for Utility Model Registration] A. A means for extracting the fundamental wave contained in a musical tone signal and measuring the frequency of this fundamental wave, and B. The frequency of the fundamental wave measured by this frequency measuring means and the name of each tone of the musical tone. A means for obtaining the ratio of the frequency assigned to each note name by comparing it with the frequency of the C12 note name, and a method in which the note name symbols representing the note names of C12 are arranged in a ring similar to a clock face, and the clock hands are A tuning device comprising: a display device which, on one side, indicates a pitch name symbol corresponding to the frequency measured by the frequency measuring means, and on the other hand of the watch, indicates the value obtained by the means for obtaining the frequency ratio; frequency measuring instrument.