JP2011186039A - Pickup device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a detection output of a pickup device without increasing the size thereof. <P>SOLUTION: A piezoelectric material vibration sensor of converting a string vibration of a stringed instrument to an electrical signal and for output of the electrical signal has the following configuration. The pickup device includes: a piezoelectric element 220 formed into plate; a piezoelectric element 120 supported on the piezoelectric element so as to be in bridge both ends of which are fixed; an oscillator 150 of transmitting a string vibration to the piezoelectric elements 120 and 220; and a signal output part 160 to output an electrical signal according to a combined electromotive force of a bending electromotive force generated in the piezoelectric element 120 by a bending wave according to the string vibration transmitted via the oscillator 150 and a compression electromotive force generated in the piezoelectric element 220 due to a pressure applied according to the string vibration. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a technique for converting string vibration of a stringed instrument into an electric signal, and more particularly to a technique for converting string vibration into an electric signal using a piezoelectric element.

  An example of an electric musical instrument that converts string vibration into an electric signal and outputs the electric signal is an electric acoustic guitar (hereinafter referred to as an electric acoustic guitar). The so-called acoustic guitar has a hollow body like a so-called acoustic guitar, and is different from a so-called electric guitar in that a performance sound can be emitted by resonance of the body. A pickup device using a piezoelectric element is often used to convert string vibration into an electric signal in an acoustic guitar. A piezoelectric element is a ceramic element that generates an electromotive force in response to an applied pressure, and is also called a piezoelectric element. For this reason, a pickup device using a piezoelectric element is sometimes called a piezo pickup device or a piezoelectric material vibration sensor. Note that Patent Documents 1 and 2 are cited as prior art documents related to this type of pick-up device.

  FIG. 9 is a diagram illustrating a configuration example of the pickup device 8 disclosed in Patent Document 1. In FIG. The pickup device 8 is embedded in a lower piece 6 (see FIG. 11) of a stringed musical instrument such as a guitar. 10A is a cross-sectional view (FIG. 11: cross-sectional view taken along line XX ′) of the lower piece 6 of the guitar in which the pickup device 8 is embedded, cut along a plane perpendicular to each string. FIG. It is sectional drawing (FIG. 11: YY 'line sectional drawing) which cut | disconnected the lower piece 6 by the plane along the longitudinal direction of a string. As shown in FIGS. 9, 10 (A), and 10 (B), the pickup device 8 is disposed so as to be sandwiched between the string receiving member 5 and the lower piece 6. As shown in FIG. 9, in the pickup device 8, the piezoelectric elements 22 are arranged in parallel on the upper surface side of the printed board 21 on which the electrodes 23 are provided so as to correspond to the respective strings 4. 24 is configured.

  When a performance operation such as repelling the string 4 is performed on the stringed musical instrument having such a pickup device 8, the vibration of the string 4 generated by the performance operation is transmitted to the piezoelectric element 22 through the string receiving member 5. Since the lower piece 6 is fixed to the body portion of the stringed instrument, a pressure corresponding to the string vibration is applied to the piezoelectric element 22 sandwiched between the string receiving member 5 and the lower piece 6, and an electromotive force corresponding to the pressure is applied. (Electromotive force represented by piezoelectric output constant G33: hereinafter, compression electromotive force) occurs. The compressed electromotive force generated in the piezoelectric element 22 is taken out as a potential difference between the electrode 23 and the electrode 24, and an electrical signal corresponding to the potential difference is output via the cable 15a or the like. Thereby, conversion of the string vibration into an electric signal is realized. The pickup device 8 disclosed in Patent Document 1 has an impedance conversion circuit 25 on the lower surface side of the printed circuit board 21, and the impedance impedance of the piezoelectric element 22 is lowered by the impedance conversion circuit 25. As a result, deterioration of sound quality due to induction hum and external noise is prevented. It should be noted that the piezoelectric elements 22 are not provided individually corresponding to the respective strings 4, but vibrations of a plurality of strings 4 may be detected collectively by one piezoelectric element 22 as shown in FIG. Of course it is good.

  FIG. 12 is a perspective view illustrating a configuration example of the pickup device disclosed in Patent Document 2. In FIG. As shown in FIG. 12, the pickup device includes two piezoelectric crystals 58 that are arranged close to each other in the longitudinal direction for each string 20. A saddle 28 as a string receiving member is placed on the two piezoelectric crystals 58, and the string 20 is supported by the saddle 28. In this pickup device, the saddle 28 presses each piezoelectric crystal 58 in accordance with the string vibration, whereby a compression electromotive force is generated in the piezoelectric crystal 58, and an electric signal corresponding to the compression electromotive force is output.

Japanese Patent Application Laid-Open No. 7-239685 JP 2001-356774 A

As shown in FIG. 13A, both of the techniques disclosed in Patent Document 1 and Patent Document 2 are piezoelectric due to a compression wave (longitudinal wave corresponding to string vibration) transmitted through a string receiving member or the like. In this technique, a compressed electromotive force generated in an element is taken out as a potential difference generated in two electrodes attached to the piezoelectric element. This compression electromotive force is proportional to the thickness of the piezoelectric element to which the electrode is attached. For example, FIG. 13B is a graph showing the relationship between the compression electromotive force and the thickness of the piezoelectric element when compression is performed with a compression wave having a frequency of 1000 Hz. As is clear from FIG. 13B, in order to avoid the influence of noise or the like and to obtain a detection output (compression electromotive force) of a certain level or more, the thickness of the piezoelectric element is more than a certain level (see FIG. 13 (B), it is necessary to be 400 μm or more. Since the thickness of the piezoelectric element is directly related to the size of the pickup device, the conventional G33 output type pickup device can improve the detection output without increasing the pickup device (or while maintaining the detection output of the pickup device). There was a problem that it was difficult to reduce the size.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a technique that makes it possible to improve the detection output without increasing the size of the pickup device.

  In order to solve the above-described problems, the present invention provides a pickup device that converts string vibration of a stringed instrument into an electric signal and outputs the electric signal, and a first piezoelectric element formed in a plate shape and the first piezoelectric element on the first piezoelectric element. A bending wave corresponding to the string vibration transmitted through the vibrator, comprising: a second piezoelectric element supported in a bridge shape; and a vibrator for transmitting the string vibration to the first and second piezoelectric elements. To output an electric signal corresponding to a combined electromotive force of the compression electromotive force generated in the first piezoelectric element due to the bending electromotive force generated in the second piezoelectric element and the pressure applied according to the string vibration. A pickup device is provided.

  Since the magnitude of the bending electromotive force (electromotive force represented by the piezoelectric output constant G31) of the piezoelectric element depends on the amount of bending strain of the piezoelectric element, the piezoelectric element reaches the limit as long as the mechanical strength can be maintained to obtain a large detection output. Can be made thinner. According to such a pickup device, the detection output can be improved without increasing the pickup device (or while maintaining the detection output of the pickup device) as compared with the conventional pickup device that uses only the compressed electromotive force. Downsizing).

  In addition, the thickness of the second piezoelectric element is set to a thickness suitable for detecting the string vibration of a sound in a higher range than the derived sound of a stringed instrument (for example, an electric acoustic guitar) to which the piezoelectric material vibration sensor is incorporated. If so, it becomes possible to obtain a detection output higher than that in the conventional case in the high sound range, and it is possible to output a complex and rich sound. In addition, as a specific mode for supporting the second piezoelectric element in a bridge shape, the shape of the substrate carrying the second piezoelectric element is changed to a plurality of legs and a bridge supported by the plurality of legs. The second piezoelectric element and the substrate may be supported in a bridge shape on the electrode placed on the first piezoelectric element (that is, serve as a bridge pier). ) A mode in which convex portions are provided may be used.

  Another aspect for solving the above-described problem is a pickup device that converts a string vibration of a stringed instrument into an electric signal and outputs the electric signal, the first piezoelectric element formed in a plate shape, and the first A second piezoelectric element mounted on the first piezoelectric element via a plate-like electrode or supported by a plurality of legs and the plurality of legs. A second piezoelectric element having a bridge portion, a vibrator for transmitting the string vibration to the first and second piezoelectric elements, and a bending wave corresponding to the string vibration transmitted through the vibrator. A mode of outputting an electric signal corresponding to a combined electromotive force of a compression electromotive force generated in the first piezoelectric element due to a bending electromotive force generated in a bridge portion of the piezoelectric element of 2 and a pressure applied according to the string vibration And piezoelectric elements formed in a prismatic cylindrical shape, and the string vibration A vibrator that transmits to one of the side walls of the piezoelectric element, and the bending electromotive force generated in the piezoelectric element by the bending wave corresponding to the string vibration transmitted through the vibrator is applied according to the string vibration A mode of outputting an electric signal corresponding to a combined electromotive force of a compression electromotive force generated in the piezoelectric element due to pressure is conceivable. In such an embodiment, a conventional G33 output piezoelectric material vibration sensor can be used as a piezoelectric material vibration sensor portion that generates a compression electromotive force in response to string vibration.

  As still another aspect of the present invention, a bridge-like piezoelectric element supported at both ends, and a vibrator for transmitting string vibration to the piezoelectric element, the string vibration transmitted through the vibrator is provided. A mode in which an electric signal corresponding to a bending electromotive force generated in the piezoelectric element by a corresponding bending wave is output can be considered. According to such an aspect, it becomes possible to further reduce the size of the pickup device. However, in order to realize such an aspect, since the compression electromotive force is not used, it is necessary to configure the pickup device using a piezoelectric element capable of generating a sufficiently large bending electromotive force.

It is a figure for demonstrating the utilization aspect of the bending electromotive force of a piezoelectric element, and the bending electromotive force in this invention. It is a figure which shows the structural example of the pick-up apparatus of 1st Embodiment of this invention. It is a figure for demonstrating the manufacturing method of the G31 output piezoelectric material vibration sensor 100 which makes the principal part of the pick-up apparatus. It is a figure which shows the structural example of the pick-up apparatus of 2nd Embodiment of this invention. It is a figure which shows the structural example of the pick-up apparatus of 3rd Embodiment of this invention. It is a figure which shows the structural example of the pick-up apparatus of 4th Embodiment of this invention. It is a figure for demonstrating a modification (1). It is a figure for demonstrating a modification (3). It is a figure for demonstrating a prior art. It is a figure for demonstrating a prior art. It is a figure for demonstrating a prior art. It is a figure for demonstrating a prior art. It is a figure for demonstrating the problem of a prior art.

(A: Usage mode of bending electromotive force of piezoelectric element and bending electromotive force in the present invention)
The present invention is characterized in that a bending electromotive force of a piezoelectric element is used for converting a string vibration into an electric signal. As shown in FIG. 1A, the bending electromotive force is a film-like (or plate-like) piezoelectric element (hereinafter, supported in a bridge shape) in which both ends are fixed and the central portion is supported so as to be able to vibrate. This is an electromotive force generated when a bending wave is generated by applying vibration to the central portion of the piezoelectric element), and is expressed by a piezoelectric output constant G31. Hereinafter, a piezoelectric material vibration sensor that converts string vibration into bending electromotive force and outputs the result is referred to as “G31 output piezoelectric material vibration sensor”.

FIG. 1B is a cross-sectional view illustrating a configuration example of the G31 output piezoelectric material vibration sensor.
More precisely, FIG. 1B shows a case where the G31 output piezoelectric material vibration sensor embedded in the lower piece 6 of the electric acoustic guitar (see FIG. 11) is cut along the line XX ′ in FIG. FIG. As shown in FIG. 1B, this G31 output piezoelectric material vibration sensor has a substrate (for example, an insulating substrate formed of silicon, zirconia, or the like) on the spacers 110a and 110b arranged with a gap a. 130 is mounted, and the substrate 130 is fixed to the spacers 110a and 110b by the fixing members 140a and 140b (for example, a portion indicated by a dotted line in FIG. 1B is screwed). A piezoelectric element 120 is formed on the substrate 130 by forming a piezoelectric material such as lead zirconate titanate (hereinafter referred to as PZT) into a film shape having a thickness T1. In the example shown in FIG. 1B, the spacer 110a and the spacer 110b serve as bridge piers, and the substrate 130 is supported in a bridge shape. Since the film-like piezoelectric element 120 is provided on the substrate 130, the film-like piezoelectric element 120 is supported in a bridge shape (or a leaf spring shape) via the substrate 130.

  One of the two fixing members shown in FIG. 1B (the fixing member 140a in FIG. 1B) is provided with an electrode in contact with the piezoelectric element 120, and transmits the string vibration to the piezoelectric element 120. An electrode that is in contact with the piezoelectric element 120 is also provided on the vibrator 150. In the G31 output piezoelectric material vibration sensor shown in FIG. 1B, the piezoelectric element 120 and the substrate 130 are bent and deformed according to the string vibration, and a bending electromotive force is generated in the piezoelectric element 120 according to the amount of bending distortion. The bending electromotive force is applied to the signal output unit 160 as a potential difference between the two electrodes, and an electric signal corresponding to the potential difference is output from the signal output unit 160.

  As described above, according to the G31 output piezoelectric material vibration sensor, the size is maintained as compared with the conventional piezoelectric material vibration sensor (hereinafter referred to as the G33 output piezoelectric material vibration sensor) that converts the string vibration into the compression electromotive force and outputs the converted vibration. It can be considered that a large detection output can be obtained while maintaining (or the device can be downsized while maintaining the detection output). Because the magnitude of the bending electromotive force depends on the amount of bending strain of the piezoelectric element, to obtain a large detection output, it is sufficient to make the piezoelectric element as thin as possible within the range where the mechanical strength can be maintained. This is because the piezoelectric vibration sensor can be downsized. Further, in the G31 output piezoelectric material vibration sensor shown in FIG. 1B, since the entire sensor is a leaf spring, a constant reaction force acts on the contact portion with the vibrator 150, and contact tuning is performed. The effect that it becomes easy is also acquired.

  Dimensions of the piezoelectric element 120 and the substrate 130 constituting the G31 output piezoelectric material vibration sensor (thickness, length in the chord direction (FIG. 11: YY ′ direction), width in the direction perpendicular to these (FIG. 11: XX ′ direction)) Various values can be considered as to what value should be set. For example, as long as one G31 output piezoelectric material vibration sensor is arranged for each of a plurality of strings, the length of the piezoelectric element 120 and the substrate 130 may be 1 to 10 mm, and the width is 2 to 2 mm. It may be 15 mm. Further, if the vibration of a plurality of strings is detected by a single G31 output piezoelectric material vibration sensor, the length of the piezoelectric element 120 and the substrate 130 may be 1 to 10 mm, and the width is 8 to 70 mm. If it is good. The thickness of the piezoelectric element 120 is preferably 1 to 1000 μm. On the other hand, the thickness T2 of the substrate 130 may be appropriately determined within a range of 0 (that is, T2 = 0 is an aspect in which the G31 output piezoelectric material vibration sensor is formed without the substrate 130) to about 2 mm. For example, as in the first embodiment described later, when a pickup device is configured by combining a G31 output piezoelectric material vibration sensor and a G33 output piezoelectric material vibration sensor, the rigidity when combined with the piezoelectric element 120 is detected. It is preferable to determine the thickness of the substrate 130 so as to be a value suitable for the sound range (for example, in the case of an electric guitar, a sound range higher than the derivative sound thereof). This is because, in this way, it is possible to obtain a detection output higher than that in the prior art in the high sound range, and it is considered possible to output a sound that is more complex and richer than in the past.

FIG. 1C shows the thickness T1 of the piezoelectric element 120 and the thickness T2 of the substrate 130 when a = 7 mm and b (width of the portion of the vibrator 150 in contact with the piezoelectric element 120) = 3.5 mm. It is a figure which shows the measurement result of the electromotive force about various combinations. More specifically, in case 1 of FIG. 1C, T1 = 100 μm and T2 = 100 μm, and in case 2, T1 = 100 μm and T2 = 500 μm. In case 3, T1 = 50 μm and T2 = 100 μm, and in case 4, T1 = 550 μm and T2 = 0 μm (that is, a bulk state without a substrate generally used for the G33 output piezoelectric material vibration sensor). Thus, it can be seen from the measurement example shown in FIG. 1C that a large electromotive force can be obtained in any of the cases 1, 2, and 3 as compared with the bulk state without the substrate.
The above is the configuration of the G31 output piezoelectric material vibration sensor.

  While the G31 output piezoelectric material vibration sensor has been described above, various modes are conceivable as a specific mode for constructing a pickup device for stringed instruments using the G31 output piezoelectric material vibration sensor. Hereinafter, specific embodiments of the present invention will be described.

(B: First embodiment)
(B-1: Configuration)
FIG. 2 is a diagram illustrating a configuration example of the pickup device according to the first embodiment of the present invention. This pickup device is embedded in the lower part of the electric acoustic guitar (the part indicated by reference numeral 6 in FIGS. 10 and 11) for converting the string vibration into an electric signal and outputting it. FIG. FIG. 12 is a cross-sectional view of the pickup device of this embodiment taken along the line XX ′ in FIG. As shown in FIG. 2, the pickup device has a configuration in which a G31 output piezoelectric material vibration sensor 100 is stacked on a G33 output piezoelectric material vibration sensor 200. In FIG. 2, the same components as those in FIG. 1 are denoted by the same reference numerals.

  In the G33 output piezoelectric material vibration sensor 200, a piezoelectric element 220 having a thickness (for example, 550 μm) thicker than the piezoelectric element 120 is bonded and laminated to an electrode 210 formed in a plate shape with a conductive metal, using a conductive adhesive or the like. The electrode 230 formed of a conductive metal so that the cross-section is U-shaped is bonded and laminated to the piezoelectric element 220 so that the recessed portion faces the substrate 130 of the G31 output piezoelectric material vibration sensor 100. ing. As shown in FIG. 2, the piezoelectric element 120 and the substrate 130 of the G31 output piezoelectric material vibration sensor 100 are supported in a bridge shape by the portion of the electrode 230 protruding toward the substrate 130. For this reason, the piezoelectric element 120 and the substrate 130 are bent and deformed according to the string vibration transmitted through the vibrator 150, and a bending electromotive force corresponding to the amount of bending strain is generated in the piezoelectric element 120. On the other hand, since the piezoelectric element 220 has a sufficient thickness, it does not bend and deform, and is pressed by the pressure of the string vibration transmitted through the vibrator 150, the piezoelectric element 120, the substrate 130, and the electrode 230, and generates a compression electromotive force. generate.

  In FIG. 2, the electrode of the fixing member 140a and the electrode 230 are electrically connected so as to be electrically connected to each other, and the electrode 210 is grounded. For this reason, it is assumed that a bending electromotive force of A [V] is generated in the piezoelectric element 120 according to the vibration of the vibrator 150, and a compression electromotive force of B [V] is generated in the piezoelectric element 220 due to the pressure corresponding to the string vibration. The potential of the electrode 230 is A [V], and the potential of the electrode provided in the vibrator 150 is A + B [V]. As a result, the signal output unit 160 outputs an electrical signal corresponding to the combined electromotive force (that is, A + B [V]) of the bending electromotive force generated in the piezoelectric element 120 and the compressed electromotive force generated in the piezoelectric element 220.

  As described above, since the thickness of the piezoelectric element 120 and the substrate 130 constituting the G31 output piezoelectric material vibration sensor 100 can be reduced within a range in which the mechanical strength can be maintained, according to the pickup device of the present embodiment, G33 is used. A larger detection output can be obtained if the size of the device is the same as compared with the case where the pickup device is configured using only the output piezoelectric material vibration sensor (in other words, the device while maintaining the size of the detection output) Can be reduced in size).

(B-2: Manufacturing method)
Next, a manufacturing method of the G31 output piezoelectric material vibration sensor 100 included in the pickup device of this embodiment will be described. As described above, in order to efficiently detect the bending electromotive force, it is necessary to reduce the thickness of the entire piezoelectric element. Therefore, in this embodiment, a method of forming the piezoelectric element 120 on the substrate 130 by screen printing is employed.

  Specifically, a paste containing PZT powder having a particle size of 0.1 to 50 μm is applied to the substrate 130 by screen printing so as to have a thickness of 25 to 50 μm, dried at 100 ° C. for 5 minutes, and then 950. Baking is performed at a temperature of 2 ° C. for 2 hours (see FIG. 3A). Thereby, the film-like piezoelectric element 120 is formed on the substrate 130. In addition, the said paste mixes PZT powder and the organic binder which plays the role of a fixing material in the organic solvent used as the base. As the organic solvent, a hydrocarbon-based or alcohol-based solvent may be used, and as the organic binder, a cellulose-based or epoxy-based solvent may be used. Moreover, the said drying process is a process for volatilizing the organic solvent contained in a paste, and the said baking process is a heat treatment process for crystallizing a PZT powder perovskite. The substrate on which the PZT layer is formed in this way is cut (diced) into a desired size and subjected to poling heat treatment to complete the G31 output piezoelectric material vibration sensor (see FIG. 3B). Thus, in this embodiment, since the piezoelectric element 120 is formed on the board | substrate 130 by screen printing, a several G31 output piezoelectric material vibration sensor can be manufactured collectively, and the manufacturing cost can be reduced.

(C: Second embodiment)
Next, a second embodiment of the present invention will be described. FIG. 4 is a cross-sectional view illustrating a configuration example of a pickup device according to the second embodiment of the present invention (similar to the first embodiment, FIG. 11XX ′ cross-sectional view). As shown in FIG. 4, the pickup device of this embodiment is configured by mounting a G31 output piezoelectric material vibration sensor 400 on a G33 output piezoelectric material vibration sensor 300. As shown in FIG. 4, the G33 output piezoelectric material vibration sensor 300 is configured by bonding and laminating electrodes 310, piezoelectric elements 320, and electrodes 330 each formed in a plate shape. Since the piezoelectric element 320 is for generating a compression electromotive force similarly to the piezoelectric element 220 in the first embodiment, it is preferable that the piezoelectric element 320 has a sufficient thickness (for example, 550 μm).

  On the other hand, the G31 output piezoelectric material vibration sensor 400 is formed of a film-shaped piezoelectric element 410 having a thickness of 100 μm, a substrate 420 that supports the piezoelectric element 410 in a bridge shape, a conductive metal, and the like. Coating members 430a and 430b covering the side surfaces are included. As shown in FIG. 4, the board | substrate 420 is formed in the shape which has a some leg part and the bridge part supported by these leg parts. When the substrate 420 is formed in such a shape, a technique such as DEEP, RIE (Reactive Ion Etching), or wet etching may be used. Also, the coating members 430a and 430b are electrically connected to the electrode 330 and play the same role as the electrodes provided on the fixing member 140a of the first embodiment.

  As shown in FIG. 4, the pickup device of this embodiment has a structure similar to the structure of a so-called membrane switch, and the central portion of the piezoelectric element 410 supported by the substrate 420 passes through the vibrator 150. The bending electromotive force A [V] corresponding to the bending strain is generated. On the other hand, the piezoelectric element 320 is pressed by the pressure transmitted through the vibrator 150, the piezoelectric element 410, the substrate 420, and the electrode 330, and generates a compression electromotive force B [V] corresponding to the pressure. Therefore, when the electrode 310 is grounded, the potential of the electrode 330 (and the coating members 430a and 430b) is B [V], and the potential of the electrode provided in the vibrator 150 is A + B [V]. . Therefore, the signal output unit 160 outputs an electrical signal corresponding to the combined electromotive force (A + B [V]) of the bending electromotive force and the compressed electromotive force.

  As described above, even in the present embodiment, a larger detection output can be obtained if the size of the device is the same as compared with the case where the pickup device is configured using only the G33 output piezoelectric material vibration sensor (in other words, The apparatus can be reduced in size while maintaining the magnitude of the detection output. In addition, the G33 output piezoelectric material vibration sensor 300 constituting the pickup device of the present embodiment is not different from that used in the conventional pickup device. That is, according to this embodiment, it is possible to manufacture the pickup device according to the present invention by diverting the existing G33 output piezoelectric material vibration sensor (or its manufacturing equipment).

(D: Third embodiment)
FIG. 5 is a diagram illustrating a configuration example of the pickup device according to the third embodiment of the present invention. As shown in FIG. 5 (A), the piezoelectric element 510 constituting the main part of the G31 output piezoelectric material vibration sensor of the pickup device of the present embodiment is formed of PZT on the piezoelectric member 510a formed in a plate shape. The piezoelectric members 510b and 510c that play the role of are sintered (or bonded and laminated). As shown in FIG. 5B, the pickup device of this embodiment is configured by bonding and laminating the piezoelectric element 510 of FIG. 5A to the G33 output piezoelectric material vibration sensor 300. Note that the signal output unit is not shown in FIG.

  In the pickup device shown in FIG. 5B, the G31 output piezoelectric material vibration sensor 500 is formed by the piezoelectric element 510, the electrode provided on the vibrator 150, and the electrode 330. That is, in the pickup device shown in FIG. 5B, the electrode 330 is shared by the G31 output piezoelectric material vibration sensor 500 and the G33 output piezoelectric material vibration sensor 300.

  In the pickup device according to the present embodiment, the central portion of the piezoelectric member 510a supported in a bridge shape is bent and deformed according to the string vibration transmitted through the vibrator 150, and the bending electromotive force A [ V] is generated. On the other hand, the piezoelectric element 320 is pressed by the pressure transmitted through the piezoelectric element 510 and the electrode 330, and generates a compression electromotive force B [V] corresponding to the pressure. Therefore, if the electrode 310 is grounded, the potential of the electrode 330 is B [V], and the potential of the electrode provided in the vibrator 150 is A + B [V]. Therefore, an electric signal corresponding to the combined electromotive force (A + B [V]) of the bending electromotive force and the compressed electromotive force is output from the signal output unit (not shown).

  As described above, even in the present embodiment, a larger detection output can be obtained if the size of the device is the same as compared with the case where the pickup device is configured using only the G33 output piezoelectric material vibration sensor (in other words, The apparatus can be reduced in size while maintaining the magnitude of the detection output. In addition, in the present embodiment, the electrode 330 is shared by the G31 output piezoelectric material vibration sensor 500 and the G33 output piezoelectric material vibration sensor 300, and a substrate for supporting the piezoelectric element 510 is not necessary. The pickup device can be configured with a smaller number of parts than in the second embodiment.

(E: Fourth embodiment)
FIG. 6 is a diagram illustrating a configuration example of a pickup device according to the fourth embodiment of the present invention. As shown in FIG. 6A, the piezoelectric element 610, which is the main part of the G31 output piezoelectric material vibration sensor of the pickup device of this embodiment, has a donut-shaped cross section (ie, a cylindrical prism column). Is characteristic). As a method for generating the piezoelectric element 610 having such a shape, as shown in FIG. 6A, the piezoelectric members 610c and 610d each serving as a spacer are spaced apart from each other between the plate-like piezoelectric members 610a and 610b. A method of arranging and sintering (or bonding) each piezoelectric member is conceivable. In the pickup device of this embodiment, as shown in FIG. 6B, the piezoelectric element 610 is placed on the plate-like electrode 620 so that the electrode provided on the vibrator 150 is in contact with the piezoelectric element 610. It is comprised by arrange | positioning the vibrator | oscillator 150 in this. In FIG. 6B, the signal output unit is not shown.

  In the pickup device shown in FIG. 6B, the piezoelectric member 610a of the piezoelectric element 610 is bent and deformed according to the string vibration transmitted through the vibrator 150, and a bending electromotive force corresponding to the amount of bending strain is generated. The other parts (piezoelectric members 610b, 610c and 610d) of the piezoelectric element 610 are not bent and deformed, and generate a compression electromotive force according to the pressure of the string vibration. For this reason, assuming that the electrode 620 is grounded, an electric signal corresponding to the combined electromotive force of the bending electromotive force and the compressed electromotive force is output from a signal output unit (not shown).

  As described above, even in the present embodiment, a larger detection output can be obtained if the size of the device is the same as compared with the case where the pickup device is configured using only the G33 output piezoelectric material vibration sensor (in other words, The apparatus can be reduced in size while maintaining the magnitude of the detection output. In the present embodiment, the electrode 330 is not required when compared with the pickup device of the third embodiment described above, and the pickup device can be configured with a smaller number of parts.

(F: Other embodiments)
Although the first to fourth embodiments of the present invention have been described above, the following modifications may of course be added to these embodiments.
(1) In the first embodiment described above, the substrate 130 that supports the piezoelectric element 120 is an insulating substrate. However, the substrate 130 is formed of a metal having low electrical resistance, such as titanium, tungsten, or platinum, and functions as an electrode. You may let them. When the substrate is formed of a conductive material, a film-like piezoelectric element layer may be provided on both surfaces of the substrate by screen printing or sputtering film formation. In this way, if the piezoelectric element layers are provided on both surfaces of the substrate, the film stress is balanced and deformation of the substrate can be suppressed. In the case where the substrate 130 is formed of a conductive material, the two substrates 130a and 130b each having a piezoelectric element film formed on one surface thereof are, as shown in FIG. 7, a spacer 710a formed of a conductive material. And 710b may be bonded and laminated back to back (so that the surfaces on which the piezoelectric element film is not formed face each other), and further bonded and laminated to the plate-like electrode 720 to form a pickup device. . For example, in the pickup device shown in FIG. 7, the substrate 130b and the electrode 720 serve as a G33 output piezoelectric material vibration sensor, and the substrate 130a serves as a G31 output piezoelectric material vibration sensor.

(2) In the first and second embodiments described above, the piezoelectric element of the G31 output piezoelectric material vibration sensor (or the G33 output piezoelectric material vibration sensor) has a single layer structure, but may have a multilayer structure. Similarly, all or part of the piezoelectric members 510a, 510b and 510c of the third embodiment may have a multilayer structure, and all or part of the piezoelectric members 610a, 610b, 610c and 610d of the fourth embodiment may have a multilayer structure. Also good.

(3) In each of the embodiments described above, the width of the vibrator 150 is made smaller than the width of the piezoelectric element, but the width of the vibrator may be made wider than the width of the piezoelectric element as shown in FIG. FIG. 8 illustrates a case where the width of the vibrator 150 is made larger than the width of the piezoelectric element 510 in the pickup device of the third embodiment described above.

(4) In each of the above-described embodiments, the pickup device is configured by combining the G31 output piezoelectric material vibration sensor and the G33 output piezoelectric material vibration sensor. However, the pickup device may be configured by only the G31 output piezoelectric material vibration sensor shown in FIG.

(5) In each of the above-described embodiments, the application example of the present invention to the pickup device that converts the string vibration of the electric acoustic guitar into an electric signal and outputs the electric signal has been described, but the application target of the present invention is the pickup device for the electric acoustic guitar. Needless to say, the present invention can be applied to pickup devices for other types of stringed instruments such as acoustic guitars.

  100, 400 ... G31 output piezoelectric material vibration sensor, 200, 300 ... G33 output piezoelectric material vibration sensor, 110a, 110b, 710a, 710b ... Spacer, 120, 220, 410, 510, 610 ... Piezoelectric element, 130, 420 ... Substrate 140a, 140b ... fixing member, 150 ... vibrator, 160 ... signal output unit, 210, 230, 310,330 ... electrode,

Claims (4)

In a pickup device that converts string vibration of a stringed instrument into an electrical signal and outputs it,
A first piezoelectric element formed in a plate shape;
A second piezoelectric element supported in a bridge shape on the first piezoelectric element;
A vibrator for transmitting the string vibration to the first and second piezoelectric elements;
With
A compression electromotive force generated in the first piezoelectric element due to a bending electromotive force generated in the second piezoelectric element by a bending wave corresponding to the string vibration transmitted through the vibrator and a pressure applied in accordance with the string vibration. A pickup device that outputs an electric signal corresponding to a combined electromotive force of electric power. In a pickup device that converts string vibration of a stringed instrument into an electrical signal and outputs it,
A first piezoelectric element formed in a plate shape;
A second piezoelectric element placed on the first piezoelectric element or on the first piezoelectric element via a plate-like electrode, wherein a plurality of legs and the plurality of legs A second piezoelectric element having a bridge portion supported by
A vibrator for transmitting the string vibration to the first and second piezoelectric elements;
Due to the bending electromotive force generated in the bridge portion of the second piezoelectric element by the bending wave according to the string vibration transmitted through the vibrator and the pressure applied according to the string vibration, the first piezoelectric element A pickup apparatus that outputs an electric signal corresponding to a combined electromotive force of a generated compression electromotive force. In a pickup device that converts string vibration of a stringed instrument into an electrical signal and outputs it,
A piezoelectric element formed in the shape of a cylindrical prism;
A vibrator for transmitting the string vibration to one of the side walls of the piezoelectric element;
With
A combined electromotive force of a bending electromotive force generated in the piezoelectric element due to a bending wave corresponding to the string vibration transmitted through the vibrator and a compression electromotive force generated in the piezoelectric element due to a pressure applied according to the string vibration. A pickup device that outputs an electrical signal in response. In a pickup device that converts string vibration of a stringed instrument into an electrical signal and outputs it,
A bridge-like piezoelectric element supported at both ends;
A vibrator that transmits the string vibration to the piezoelectric element,
An electric signal corresponding to a bending electromotive force generated in the piezoelectric element by a bending wave corresponding to a string vibration transmitted through the vibrator is output.

Images