JPS595926A - Electronic tuning apparatus - Google Patents

Abstract

PURPOSE:To enable the identification of the musical interval for a musical tone without any mechanical switch by automatically deciding and displaying the scale for a tone signal through a switched capacitor filter section, a musical tone measuring section, a scale searching circuit and a loop of the filter section. CONSTITUTION:This apparatus is provided with a switch capacitor filter section 2 for receiving an output from a musical tone detecting section 1, a musical tone measuring section 3 for receiving an output thereof, a musical scale searching circuit 5 for receiving another output thereof 3, an input means for inputting the output thereof to the filter section 2 and a reference clock generation section 6 for inputting a reference clock to the measuring section 3 and the searching circuit 5. A tone signal is automatically identified by a loop of the filter section 2, the measuring section 3, the searching circuit 5 and the filter section 2 and the scale identified is displayed.

Description

[Detailed Description of the Invention] The present invention relates to an electronic tuner, and in particular, it is capable of automatically determining pitches of musical tones without using a mechanical changeover switch, and is also capable of being miniaturized, reducing power consumption, and being made into a single-chip IT. It concerns possible new improvements.

This type of electronic tuner that has been used in the past has two types of scale selection: octave and
Some tuning machines have a scale selection switch, and by selecting these switches, the pitches of musical tones near the set scale are determined, and the pitch deviation is displayed using a meter or LED. With this type of tuner, it is necessary to change the scale manually, so it is only at the beginning of the wind performance that you need to know the pitch of an instrument such as a flute that requires both hands to play. It can only be used. In other words, as mentioned above, it is not possible to know whether the pitch of the flute being played is accurate or not by using the tuner.

Another type of tuner is a strobe type tuner as shown in FIG. This type of tuner has 12 windows, one for each 12-tone scale. The □ circle of each window rotates at a speed corresponding to the musical scale frequency. Each disk is rotated by a constant-speed rotary drive force from one motor and a gear, which is set to a frequency corresponding to each musical scale. On this disk, a matching window disk 1 whose light is modulated by a musical tone signal, appears as if it were static due to the strobe phenomenon. With this type of tuner, there is no need to switch between scales and you can learn the scale, but
When the pitch shifts, you can tell the direction of the pitch shift, but you cannot know the pitch quantitatively. In addition, since it uses a moku disk, the shape is large and the electroconvulsive capacity is large, so
There were drawbacks such as the difficulty of small 1-hi.

The purpose of this invention is to provide an extremely effective method for quickly eliminating the above-mentioned drawbacks, and in particular, by using a switched capacitor filter as the filter, the filter band can be It can be moved freely. In other words, the band of the switched capacitor filter can be moved according to the result of counting the pitches of the musical instrument and in response to the input signal, so it is possible to automatically find the scale, and it is highly accurate. We have achieved a tuner that can perform good input signal processing and can be miniaturized.

Hereinafter, preferred embodiments of the tuner according to the present invention will be described in detail with reference to the drawings.

In FIG. 1, the reference numeral 1 indicates a musical tone detection section, and the reference numeral 2 indicates a portion of a switched capacitor filter. Further, the reference numeral 3 is a musical tone measuring section, and the reference numeral 4
is a scale display section.

FIG. 2 is a block diagram of an embodiment of the basic block diagram of FIG. 1.

The musical instrument sounds are collected by the musical tone collecting section 11, amplified by the MF section 12, and inputted to the 10th bass filter 21 at the next stage. The output signal of this tenth bus filter part 21 is input to the switched capacitor filter part ρ,
band p wave, and the next stage LPII' section CTi) 23'fr
It passes through and is transmitted to the next stage. In the switched cano 5 jitter filter part 2, the 10th bass film part 21 C. Cuts the high frequency components of the musical tone, 1. The switched filter 4 creates a mixed key with the non-lock signal, This prevents the filter characteristics from deteriorating. or,
Part of the 20th low-pass filter downstream of the switched capitor 239 is reflected in the filter output. 7 is also used to remove high frequency switching and switching noise caused by the filter clock.

The output of the 20th filter field is inputted to the cycle counting section 32 via the sirlomite and trigger section 31'ft. The period counter 32 receives the coefficient 6a from the reference clock generator 6 as another input, and this reference clock p
, the period of the musical tone signal from the switched cabaret Z I part 2 is counted by 0° period, and the 9th output is:
The result of N judgment which is input to the scale judgment light 33 is as follows.
It is input to the scale display section 4. The sound lf display section 4 includes an octave display section 41, a scale display section 421, and a pitch display section 43.
It consists of an oak scale, a pitch, and a pitch. An external view showing this display pattern is shown in FIG. 3 or 4. The other output 33d of the scale judgment foot section 33 is compared with the scale - period before to determine whether it is the same scale or not, and is inputted to the scale judgment signal 33df and the scale search circuit section 52.

In the scale search circuit 52, the scale determination signal 33d is 1.
The sunset tone of the switched capacitor filter 22 is adjusted depending on four conditions: whether it matches the previous scale but is off to the lower end, off to the higher end, or no signal at all. A signal indicating whether to set the clock to the same level as 18 periods ago, or to set the clock low (or high) is input to the next stage filter clock generation section 51.This causes the output signal 51α of the filter clock generation section 51 to is applied to the switched cabaret filter n.In this way, it is possible to automatically search for the note 1'ift according to the input signal and find the correct scale.
・With this configuration, it is possible to realize an auto-tuning tuner that does not require a conventional mechanical switch for changing octave scales, and it is possible to dynamically discriminate pitches while playing an instrument. becomes. In addition, it is possible to create a small, thin tuner without using many parts, and it can accurately extract the fundamental wave of musical sounds, which is unprecedented.
It is possible to realize a tuner that is easy to tune.

[Brief explanation of the drawing]

FIG. 1 is a basic block diagram showing an electronic tuner according to the present invention, FIG. 2 is a detailed block diagram of the present invention for embodying the configuration of FIG. 1, and FIGS. FIG. 5 is a side view showing the external appearance of the device, and FIG. 5 is a perspective view showing the external appearance of the strobe type tuner. 10. Musical tone detection section 2! , switch, de, capacitor filter part 3
゜. Musical tone measurement section 4. . Children's floor display section 50. F-th floor search circuit section 6゜, reference clock generation section Above Figure 1

Claims (1)

[Claims] A switched capacitor filter for inputting the output from the musical tone detection section, a musical tone measuring section for inputting the output of the switched capacitor filter for inputting the output, and a section for inputting the output of one of the musical tone measuring sections. a scale display section,
a musical scale search circuit for inputting the other output of the musical tone measuring section; input means for inputting the output of the tone 11-1--ch circuit to a portion of the switched capacitor filter; and the musical tone measuring circuit. Part and scale search episode ii! It is equipped with a reference clock generator for inputting the iK reference clock, and sends the musical tone signal to a loop consisting of a part of the switched capacitor filter, a musical tone measuring part, a scale search circuit, and a part of the switched capacitor film. , automatically determines the scale,
An electronic tuner comprising a configuration that displays a determined scale.