JPH0617193Y2 - Electronic musical instrument pickup device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to improvement of a pickup device for an electronic musical instrument.

(Prior Art) Some electronic musical instruments are configured so that musical tones of various timbres can be generated from a sound source module by playing the musical instrument.

The conventional pickup device in this kind of electronic musical instrument is
The physical vibration of a musical instrument vibrating body accompanied by a performance is converted into an electric signal by a sensor such as a piezoelectric element or a microphone mechanism, and this electric signal is directly output as a trigger signal to a sound source module so that the musical sound can be produced. Met.

However, generally, in this type of electronic musical instrument, the vibration of the musical instrument is not physically induced only by playing, but the resonance of the vibration causes physical vibration, and the pickup device outputs a trigger signal. Then, there is a problem that a musical sound is produced from the sound source module.
Particularly in percussion instruments, the vibration of the drum head (vibrating body) is not limited to the striking along with the performance, but may be caused by the sound of the monitor, the striking sound of the adjacent drum, or the shaking of the violent stage action. When the vibration having a frequency close to the frequency is generated, the drum head may easily resonate, and there is a sufficient possibility that the sound source module may make an erroneous sound due to the trigger signal output of the pickup device.

In order to solve such a problem, conventionally, a gate circuit described below is provided on the sound source module side of an electronic musical instrument to prevent musical tones from being generated due to resonance of the vibrating body of the musical instrument. ing. In other words, the maximum output of the trigger signal generated by resonance is about 300 mV for the pickup device in which the maximum output of the trigger signal generated by hitting the drum is about 7 V. Output value (3
(00 mV) is set as a set value to cut off all trigger signals having an output value less than the set value so that no musical sound is produced due to resonance of the drum head.

However, when the trigger signal of the conventional pickup device is cut by the gate circuit, in addition to the trigger signal by resonance, if the output is 300 mV or less, even a trigger signal by hitting is cut by the gate circuit and a musical tone is generated. The dynamic range is restricted so that no sound is produced, that is, about 4% of the maximum output is not produced.
I could not express subtle tones.

(Problems to be Solved by the Invention) The present invention has been proposed in view of the above-mentioned problems in the related art, and the purpose thereof is to:
The output value of the trigger signal due to the resonance of the musical instrument vibrating body can be greatly reduced compared to the trigger signal due to performance,
An object of the present invention is to provide a pickup device capable of expanding a dynamic range of an electronic musical instrument and expressing subtle sounds.

(Means for Solving Problems) A pickup device according to the present invention converts a physical vibration of a vibrating body of a musical instrument into an electric signal by a sensor unit, and outputs a trigger signal for generating a musical sound from a sound source module. In this configuration, a filter for removing at least the resonance frequency band of the vibrating body of the electric signal from the electric signal is provided.

(Operation) That is, in the device of the present invention, among the electric signals from the sensor unit, the electric signal generated by the resonance of the vibrating body is
The filter greatly reduces (eliminates), and almost only the electric signal due to the performance passes through the filter and is output to the sound source module as a trigger signal.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.
1 of the accompanying drawings, FIG. 1 is a circuit diagram of a pickup device showing a first embodiment of the present invention, FIG. 2 is a bottom sectional view showing the structure of a sensor portion, and FIG. FIG. 4 is a block diagram of the second embodiment, FIG.
FIG. 5 is a circuit diagram showing the third embodiment, FIG. 6 is a circuit diagram showing the fourth embodiment, and FIG. 7 is a waveform diagram for explaining the processing contents of an electric signal by the device of the present invention.

As shown in FIG. 3, the pickup device of this embodiment is configured to output a trigger signal to the sound source module M by hitting the vibrating body of the drum D and the drum head DH to generate a musical sound. The main configuration is composed of a sensor unit 10 for converting the physical vibration of the drum head DH into an electric signal, and a filter 30 for removing at least the resonance frequency band of the drum head DH of the electric signal from the electric signal. Has become.

FIG. 1 shows a circuit diagram of the first embodiment device. This device comprises a sensor unit 10, a charge amplifier 20, a filter 30, and a power supply unit 40 for the charge amplifier 20 and the filter 30.

The sensor unit 10 may use a piezoelectric sensor 11 as shown in FIG. 2 instead of converting vibration into an electric signal by electric induction like a microphone mechanism. In the figure, reference numeral 13 is a piezoelectric element, 15 is a back side terminal plate, and 17 is a wiring code.

Since the piezoelectric element 13 has a large charge output in the resonance frequency band, it is preferable to use a piezoelectric sensor in which silicon rubber 19 or the like is applied around the piezoelectric element 13 to suppress output fluctuation. This sensor unit 10
As shown in FIG. 3, is attached by a double-sided tape or the like to the edge of the front surface (striking surface) or the back surface of the drum head of the percussion instrument.

The charge output from the sensor unit 10 caused by the vibration of the drum head is input to the charge amplifier 20. The charge output from the piezoelectric element or the like is easily affected by the capacitance of the wiring cord or noise and fluctuates, so that the charge amplifier 20 outputs a constant electric signal.

FIG. 7 shows an electric signal output from the charge amplifier 20. The vertical axis of the figure indicates the magnitude of the electric signal (d
B), the horizontal axis represents time (t).

As shown by the thin line 25 in the figure, there are some differences depending on the type of drum, but 3K by striking the drum head
It is composed of a composite wave of a frequency component 25a of about Hz to 5 KHz and a resonance frequency component 25b of the drum head of 100 Hz to 200 Hz.

The electric signal 25 is input to the filter 30 shown in FIG. The filter 30 of this embodiment is an operational amplifier 3
2 is a second-order high-pass filter using 1. Of course, higher performance can be achieved by using a higher order filter. Reference numeral 33 in the drawing is its output end.

As shown in FIG. 7, in the filter 30,
Resonance frequency component 25 of the drumhead of the electrical signal 25
Since the passage of b through the filter is blocked and greatly reduced (removed), the frequency component 25a is almost generated by the striking of the drum head.
It becomes the electric signal 35 constituted by only. The electric signal 35 is output to the sound source module M as a trigger signal.

As is well known, the cut-off frequency of the filter 30 can be set by adjusting the capacitor C1 and the resistor R1. For example, if this is set to 1 KHz, the output in the frequency band of the resonance frequency of the head of 100 Hz to 200 Hz is about 24 dB. It can be reduced (to 1/16).

The power supply unit 40 is for the charge amplifier 20 and the filter 30, and a direct current Ev = 9V is applied to the input end 45 by a battery or the like.

According to experiments conducted by the inventors of the present invention on the device of the first embodiment, when the maximum output of the trigger signal is 4 V, the maximum output generated by the resonance of the drum head is 70 mV.
The maximum output is about 2 even if the gate circuit is used.
It has been found that it becomes possible to express even a small sound of about% (conventionally about 4%).

FIG. 4, FIG. 5, and FIG. 6 show the circuit diagrams of the other embodiments. These do not require the power supply unit as in the first embodiment. Reference numeral 10 in the figure is the sensor unit.

What is shown in FIG. 4 is a high-pass filter 50 similar to that of the first embodiment. The ones shown in FIGS. 5 and 6 are band stop filters 60 and 70.
This is because only the resonance frequency band of the musical instrument vibrating body of the electric signal from the sensor unit 10 is removed from the electric signal.

As is well known, the cut-off frequencies of these filters 50, 60 and 70 are the respective capacitors C2, C3.
It is set by adjusting C4 and reactances L2, L3 and L4.

(Effect) As described and illustrated above, according to the present invention, at least the resonance frequency band of the vibrating body of the electric signal obtained by the physical vibration of the vibrating body of the musical instrument is removed from the electric signal by the filter. Therefore, it is possible to greatly reduce the output of the electric signal due to the resonance of the musical instrument vibrating body caused by the sound of the monitor, the sound of the adjacent musical instrument, or the shaking due to the violent stage action, which does not depend on the performance. Therefore, the set output value of the trigger signal of the pickup device to be cut in the gate circuit on the sound source module side can be significantly reduced,
Now it is possible to pronounce even small sounds if they are actually played.

As described above, the pickup device of the invention can significantly reduce the output value of the trigger signal due to the resonance of the musical instrument vibrating body as compared with the trigger signal due to the performance, and it is possible to increase the dynamic range of the electronic musical instrument and make it delicate. It became possible to express sound.

[Brief description of drawings]

1 is a circuit diagram of a pickup device showing a first embodiment of the present invention, FIG. 2 is a bottom sectional view showing a structure of a sensor portion,
FIG. 3 is a block diagram illustrating a state in which the present apparatus is used in a percussion instrument, FIG. 4 is a circuit diagram showing a second embodiment, FIG. 5 is a circuit diagram showing a third embodiment, and FIG. FIG. 7 is a circuit diagram showing an embodiment, and FIG. 7 is a waveform diagram for explaining the processing contents of an electric signal by the device of the present invention. 10 ... Sensor section, 20 ... Charge amplifier, 30 ...
High-pass filter, 40 ... Power supply unit, 50 ... High-pass filter, 60 ... Band stop filter, 70 ... Band stop filter, D ... Drum, DH ... Drum head (vibrating body), M ... … Sound module.

Claims (1)

[Scope of utility model registration request] 1. A sensor in which physical vibration of a vibrating body of a musical instrument is converted into an electric signal by a sensor unit, and a trigger signal for producing a musical sound is output from a sound source module, wherein at least the vibration of the electric signal. A pickup device in an electronic musical instrument, comprising a filter for removing a resonance frequency band of a body from the electric signal.