Stringed instruments and pickups

Abstract

To provide a stringed instrument capable of correctly outputting a detection signal in response to movement of a saddle while eliminating need for formation of a buckling to the saddle and groove and adhesion of a piezoelectric element.SOLUTION: A stringed instrument comprises: an instrument body 2; strings; a saddle 5 inserted into a groove 9 formed in the instrument body 2 to support the strings; and a pickup 6 including a piezoelectric element 20 that has a porous layer expandable and deformable in the thickness direction and outputs a detection signal in response to expansion and contraction of the porous layer. The piezoelectric element 20 is disposed between a first inner side 9a of the groove 9 and a first side 5a of the saddle 5. Width W9 of the groove 9 from the first inner side 9a of the groove 9 to a second inner side 9b is greater than width W5 of the saddle 5 in an arrangement direction of the first inner side 9a and the second inner side 9b. Thickness T20 of the piezoelectric element 20 without load in the direction of the arrangement is greater than or equal to difference between the width W9 of the groove 9 and the width W5 of the saddle 5.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to stringed instruments and pickups. [Background technology]

[0002] Patent Document 1 discloses a stringed instrument in which a saddle that supports the strings is fitted into a groove formed in the body, and a piezo element is disposed between the side of the saddle and the inner surface of the groove. In this stringed instrument, the piezo element outputs an electric signal (detection signal) based on changes in the pressure acting on the piezo element as the strings vibrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-33806 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the piezoelectric element described in Patent Document 1 is stiff and has a small amount of expansion and contraction. For this reason, the thickness of the piezoelectric element placed between the side surface of the saddle and the inner surface of the groove must be set with high precision relative to the distance between the side surface of the saddle and the inner surface of the groove. In other words, it is difficult to install the piezoelectric element without leaving a gap between the side surface of the saddle and the inner surface of the groove. Furthermore, because the piezoelectric element has a small amount of expansion and contraction, when the distance between the side of the saddle and the inner surface of the groove increases due to changes in string vibration or string tension, the piezoelectric element is likely to separate from the side of the saddle or the inner surface of the groove, which may prevent it from outputting a correct detection signal.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a pickup and a stringed instrument that can easily install a piezoelectric element between the side of the saddle and the inner surface of the groove, and that can correctly output a detection signal corresponding to the movement of the saddle. [Means for solving the problem]

[0006] A first aspect of the present invention includes a musical instrument body, a string, a saddle that is inserted into a groove formed in the musical instrument body to support the string, and a pickup that has a porous layer that is expandable and contractible in a thickness direction and includes a piezoelectric element that outputs a detection signal in response to the expansion and contraction deformation of the porous layer, wherein the piezoelectric element includes at least a first piezoelectric element that is disposed between a first inner surface of the groove and a first side surface of the saddle, and the width of the groove from the first inner surface of the groove to a second inner surface of the groove that faces the first inner surface is greater than the width of the saddle in an arrangement direction of the first inner surface and the second inner surface, and the thickness of the first piezoelectric element in the arrangement direction when no load is applied is equal to or greater than the difference between the width of the groove and the width of the saddle. The first piezoelectric element is disposed between a first inner surface of the groove and a first side surface of the saddle in a state in which the porous layer is compressed in the thickness direction. It is a string instrument.

[0007] A second aspect of the present invention is a pickup comprising: a musical instrument body; a string; a saddle that is inserted into a groove formed in the musical instrument body to support the string; and a pickup having a porous layer that is expandable and contractible in a thickness direction and including a piezoelectric element that outputs a detection signal in response to the expansion and contraction deformation of the porous layer, wherein the piezoelectric element includes a first piezoelectric element that is disposed between at least a first inner surface of the groove and a first side surface of the saddle, and the width of the groove from the first inner surface of the groove to a second inner surface of the groove that faces the first inner surface is greater than the width of the saddle in an arrangement direction of the first inner surface and the second inner surface, and the thickness of the first piezoelectric element in the arrangement direction under no load is smaller than the difference between the width of the groove and the width of the saddle. The first piezoelectric element is disposed between a first inner surface of the groove and a first side surface of the saddle in a state in which the porous layer is compressed in the thickness direction. It is a string instrument.

[0008] A third aspect of the present invention is a piezoelectric element having a porous layer that is expandable and contractible in a thickness direction, and that outputs a detection signal in response to the expansion and contraction deformation of the porous layer, wherein the piezoelectric element includes a first piezoelectric element disposed at least between a first inner surface of a groove formed in a body of a stringed instrument and a first side of a saddle of the stringed instrument inserted into the groove, wherein the width of the groove from the first inner surface of the groove to a second inner surface of the groove facing the first inner surface is greater than the width of the saddle in an arrangement direction of the first inner surface and the second inner surface, and the thickness of the first piezoelectric element in the arrangement direction under no load is equal to or greater than the difference between the width of the groove and the width of the saddle. The first piezoelectric element is disposed between a first inner surface of the groove and a first side surface of the saddle in a state in which the porous layer is compressed in the thickness direction. It's a pickup.

[0009] A fourth aspect of the present invention is a piezoelectric element having a porous layer that is expandable and contractible in a thickness direction, and that outputs a detection signal in response to the expansion and contraction deformation of the porous layer, wherein the piezoelectric element includes a first piezoelectric element disposed at least between a first inner surface of a groove formed in a musical instrument body of a stringed instrument and a first side surface of a saddle of the stringed instrument inserted into the groove, wherein the width of the groove from the first inner surface of the groove to a second inner surface of the groove facing the first inner surface is greater than the width of the saddle in an arrangement direction of the first inner surface and the second inner surface, and the thickness of the first piezoelectric element in the arrangement direction under no load is smaller than the difference between the width of the groove and the width of the saddle. The first piezoelectric element is disposed between a first inner surface of the groove and a first side surface of the saddle in a state in which the porous layer is compressed in the thickness direction. It's a pickup. [Effects of the Invention]

[0010] According to the present invention, the piezoelectric element can be easily installed between the side surface of the saddle and the inner surface of the groove, and the pickup can correctly output a detection signal corresponding to the movement of the saddle. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a perspective view showing a stringed instrument according to a first embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged cross-sectional view schematically showing a main part of the stringed instrument of FIG. 1. [Figure 3] 1 is a cross-sectional view schematically showing a pickup according to a first embodiment of the present invention. [Figure 4] FIG. 2 is an enlarged cross-sectional view showing a state in which no tension of the string is acting on the saddle in the first embodiment of the present invention. [Figure 5] FIG. 2 is an enlarged cross-sectional view showing a state in which tension of the string acts on the saddle in the first embodiment of the present invention. [Figure 6] FIG. 10 is an enlarged cross-sectional view showing a main part of a stringed instrument according to a second embodiment of the present invention. [Figure 7] FIG. 4 is a cross-sectional view schematically showing a pickup according to a second embodiment of the present invention. [Figure 8] FIG. 7 is an enlarged cross-sectional view showing a state in which the tension of the string acts on the saddle from the state shown in FIG. 6. [Figure 9] FIG. 10 is an enlarged cross-sectional view of a main part of a stringed instrument according to a third embodiment of the present invention, showing a state in which tension of the strings is not acting on the saddle. [Figure 10] FIG. 10 is an enlarged cross-sectional view of a main part of a stringed instrument according to a third embodiment of the present invention, showing a state in which tension of the string is applied to the saddle. DETAILED DESCRIPTION OF THE INVENTION

[0012] (First embodiment) A first embodiment of the present invention will be described below with reference to FIGS. As shown in FIGS. 1 and 2, the stringed instrument 1 of the first embodiment is a guitar, and includes an instrument body 2, a neck 3, strings 4, a saddle 5, and a pickup 6.

[0013] As shown in FIG. 1 , the instrument body 2 has a body 7 and a bridge 8 provided on the surface of the body 7. The neck 3 extends in one direction from the body 7 of the instrument body 2. A string 4 is stretched across the instrument body 2 and the neck 3. Specifically, a first end of the string 4 is fixed to a string fixing portion 11 provided on the bridge 8. A second end of the string 4 is wound by a winder 12 provided at the tip of the neck 3.

[0014] As shown in FIG. 2, the saddle 5 is inserted into a groove 9 formed in the bridge 8 of the instrument body 2. When inserted into the groove 9, the saddle 5 supports the string 4 stretched across the instrument body 2 and the neck 3. Specifically, the groove 9 is recessed from the surface 8a of the bridge 8. A portion of the saddle 5 inserted into the groove 9 protrudes from the surface 8a of the bridge 8. A tip portion 5T of the saddle 5 protruding from the surface 8a of the bridge 8 supports the string 4. The groove 9 of the bridge 8 and the saddle 5 inserted into the groove 9 are located between the neck 3 and the string fixing part 11 in the longitudinal direction of the string 4 (the left-right direction in FIG. 2).

[0015] The pickup 6 detects vibrations of the strings 4 stretched across the instrument body 2 and the neck 3, and outputs a detection signal corresponding to the vibrations of the strings 4. The detection signal is an electrical signal that is used to output sound from a speaker. The pickup 6 includes a piezoelectric element 20 that is provided between the groove 9 of the instrument body 2 and the saddle 5. 3, the piezoelectric element 20 is formed in a plate shape and includes a porous layer 21 and electrode layers 22 and 23. The piezoelectric element 20 generates a voltage in response to expansion and contraction deformation of the porous layer 21 in the thickness direction, and outputs an electric signal (detection signal).

[0016] The porous layer 21 is formed in a plate shape and is elastically expandable and contractible in the thickness direction. The porous layer 21 has a plurality of pores 24 therein. This allows the piezoelectric element 20 including the porous layer 21 to expand and contract more readily than a conventional piezoelectric element. The main component forming the porous layer 21 is preferably one that can be charged, such as polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polyvinyl chloride, polyolefin-based resins, fluorine-based resins, etc. The term "main component" refers to the component with the highest content, for example, a component with a content of 50% by mass or more.

[0017] The porous layer 21 is generally formed by subjecting a plate-like body whose main component is one of these synthetic resins to a polarization treatment. Examples of polarization treatment methods include a method of injecting a charge by applying a direct current or pulsed high voltage, a method of injecting a charge by irradiating with ionizing radiation such as gamma rays or electron beams, and a method of injecting a charge by corona discharge treatment.

[0018] The electrode layers 22 and 23 are laminated on both sides of the porous layer 21 in the thickness direction. These two electrode layers 22 and 23 are each connected to a lead wire (not shown). The material forming the electrode layers 22 and 23 may be at least a conductive material, such as various metals such as aluminum and silver, alloys of these metals, carbon, etc. The method for laminating the electrode layers 22 and 23 on the porous layer 21 is not particularly limited, and examples thereof include vapor deposition of aluminum, printing with carbon conductive ink, and coating and drying of silver paste.

[0019] The piezoelectric element 20 (first piezoelectric element) is disposed between the first inner side surface 9a of the groove 9 and the first side surface 5a of the saddle 5, as shown in FIG.

[0020] When the saddle 5 is inserted into the groove 9, the first inner surface 9a of the groove 9 and the first side surface 5a of the saddle 5 face each other in the longitudinal direction of the string 4 supported by the saddle 5. The first inner surface 9a of the groove 9 and the first side surface 5a of the saddle 5 are located on the neck 3 side in the longitudinal direction of the string 4. On the other hand, the second inner surface 9b of the groove 9, which faces the first inner surface 9a of the groove 9 in the longitudinal direction of the string 4, is located on the string fixing portion 11 side in the longitudinal direction of the string 4. The second inner surface 9b of the groove 9 faces the second side surface 5b of the saddle 5 inserted into the groove 9, which faces the opposite side to the first side surface 5a.

[0021] 4, the width W9 of the groove 9 from the first inner side surface 9a to the second inner side surface 9b is larger than the width W5 of the saddle 5 from the first side surface 5a to the second side surface 5b. Therefore, when the saddle 5 is inserted into the groove 9 so that the second side surface 5b of the saddle 5 contacts the second inner side surface 9b of the groove 9, a gap is formed between the first inner side surface 9a of the groove 9 and the first side surface 5a of the saddle 5.

[0022] The piezoelectric element 20 is disposed between the first inner surface 9a of the groove 9 and the first side surface 5a of the saddle 5 so that its thickness direction faces the arrangement direction of the first inner surface 9a of the groove 9 and the first side surface 5a of the saddle 5. In this embodiment, the thickness T20 of the piezoelectric element 20 when unloaded is equal to the difference between the width W9 of the groove 9 and the width W5 of the saddle 5. The unloaded state of the piezoelectric element 20 refers to a state in which no external force is acting on the piezoelectric element 20 and the piezoelectric element 20 is not elastically expanding or contracting. Therefore, when the piezoelectric element 20 is simply disposed between the first inner surface 9a of the groove 9 and the first side surface 5a of the saddle 5, the piezoelectric element 20 is not compressed in the thickness direction but is in contact with the first inner surface 9a and the first side surface 5a. In this state, the saddle 5 can only move toward the first inner surface 9a of the groove 9 and cannot move away from the first inner surface 9a of the groove 9. Therefore, contact between the piezoelectric element 20 and the first inner surface 9a of the groove 9 and the first side surface 5a of the saddle 5 is maintained.

[0023] With the saddle 5 and piezoelectric element 20 positioned in the groove 9 as described above, when the string 4 stretched between the string fixing portion 11 of the instrument body 2 and the neck 3 is supported by the tip portion 5T of the saddle 5, an external force based on the tension of the string 4 acts on the saddle 5. Specifically, the string 4 stretched between the string fixing portion 11 of the instrument body 2 and the neck 3 pushes the tip portion 5T of the saddle 5 toward the neck 3. This causes the saddle 5 to move so as to tilt toward the first inner surface 9a of the groove 9, resulting in the piezoelectric element 20 being compressed in its thickness direction. In this state, a gap is created between the second inner surface 9b of the groove 9 and the second side surface 5b of the saddle 5. The thickness of the piezoelectric element 20 compressed as described above may be, for example, 50% or more of the thickness T20 of the piezoelectric element 20 under no load, but is more preferably, for example, 70% or more. In other words, it is preferable that the amount of compression of the piezoelectric element 20 due to an external force is small. This is because the smaller the amount of compression of the piezoelectric element 20, the higher the sensitivity of the piezoelectric element 20.

[0024] In the stringed instrument 1 of this embodiment configured as described above, vibrations of the strings 4 are transmitted to the piezoelectric element 20 via the saddle 5, causing the porous layer 21 of the piezoelectric element 20 to expand and contract in its thickness direction. As a result, the piezoelectric element 20 outputs a detection signal (electrical signal) corresponding to the expansion and contraction deformation of the porous layer 21.

[0025] As described above, in the pickup 6 and stringed instrument 1 of this embodiment, the piezoelectric element 20 has the porous layer 21. The piezoelectric element 20 is more elastic than a piezoelectric element (e.g., a conventional piezoelectric element) that does not have the porous layer 21. Therefore, by allowing the piezoelectric element 20 to expand and contract in its thickness direction, the piezoelectric element 20 can be installed without a gap between the first side surface 5a of the saddle 5 and the first inner surface 9a of the groove 9, even if the thickness T20 of the piezoelectric element 20 under no load does not need to be set with high precision relative to the distance between the first side surface 5a of the saddle 5 and the first inner surface 9a of the groove 9, as in the conventional case. In other words, even if the dimensional precision of the piezoelectric element 20 is low, the piezoelectric element 20 can be easily installed between the first side surface 5a of the saddle 5 and the first inner surface 9a of the groove 9. Furthermore, because the amount of expansion and contraction of the piezoelectric element 20 is large, even if the distance between the first side surface 5a of the saddle 5 and the first inner side surface 9a of the groove 9 increases due to string vibration or the like, the piezoelectric element 20 is less likely to separate from the first side surface 5a of the saddle 5 and the first inner side surface 9a of the groove 9. This allows the piezoelectric element 20 placed between the saddle 5 and the groove 9 to expand and contract in accordance with the movement of the saddle 5, and as a result, the piezoelectric element 20 can correctly output a detection signal.

[0026] Furthermore, in the pickup 6 and stringed instrument 1 of this embodiment, the width W9 of the groove 9 extending from the first inner surface 9a to the second inner surface 9b is greater than the width W5 of the saddle 5 extending from the first side surface 5a to the second side surface 5b. Furthermore, the thickness T20 of the piezoelectric element 20 disposed between the first inner surface 9a of the groove 9 and the first side surface 5a of the saddle 5 under no load is equal to the difference between the width W9 of the groove 9 and the width W5 of the saddle 5. Therefore, even if the saddle 5 moves in the direction of arrangement of the first side surface 5a of the saddle 5 and the first inner surface 9a of the groove 9, the piezoelectric element 20 does not move away from the first side surface 5a of the saddle 5 and the first inner surface 9a of the groove 9. This allows the piezoelectric element 20 to expand and contract in response to the movement of the saddle 5 without being bonded to the saddle 5 or the groove 9. As a result, a detection signal can be correctly output from the piezoelectric element 20. In other words, a detection signal can be correctly output from the pickup 6 in response to the movement of the saddle 5 without the need to bond the piezoelectric element 20 to the saddle 5 or the groove 9. Furthermore, since it is no longer necessary to adhere the piezoelectric element 20 to the saddle 5 or groove 9, the saddle 5 can be easily replaced or adjusted.

[0027] 5 , in the pickup 6 and stringed instrument 1 of this embodiment, the piezoelectric element 20 is disposed between the first inner surface 9a of the groove 9 and the first side surface 5a of the saddle 5, with the porous layer 21 compressed in the thickness direction by the tension of the string 4. In this state, when the saddle 5 is displaced in a direction toward the first inner surface 9a of the groove 9 in conjunction with the vibration of the string 4, the porous layer 21 of the piezoelectric element 20 is further compressed. Furthermore, when the saddle 5 is displaced in a direction away from the first inner surface 9a of the groove 9, the porous layer 21 of the piezoelectric element 20 is expanded. This allows the piezoelectric element 20 to detect displacement of the saddle 5 in a direction toward and away from the first inner surface 9a of the groove 9.

[0028] In the first embodiment, the thickness T20 of the piezoelectric element 20 under no load may be greater than, for example, the difference between the width W9 of the groove 9 and the width W5 of the saddle 5. In this case, the piezoelectric element 20 is disposed between the first inner surface 9a and the first side surface 5a with the porous layer 21 compressed in its thickness direction. Even with this configuration, the piezoelectric element 20 can detect displacement of the saddle 5 in the direction toward and away from the first inner surface 9a of the groove 9, similar to the first embodiment described above.

[0029] In the first embodiment, the piezoelectric element 20 may be bonded to, for example, the first side surface 5a of the saddle 5 or the first inner surface 9a of the groove 9. In this case, when the saddle 5 is displaced in a direction away from the first inner surface 9a of the groove 9 in response to string vibration, even if the piezoelectric element 20 elongates relative to its no-load state, the piezoelectric element 20 can detect the displacement of the saddle 5.

[0030] Second Embodiment Next, a second embodiment of the present invention will be described with reference to Figures 6 to 8. In the following description, components common to those already described will be assigned the same reference numerals and duplicated description will be omitted.

[0031] As shown in Fig. 6, in the stringed instrument of the second embodiment, similarly to the first embodiment, a saddle 5 inserted into a groove 9 of a bridge 8 supports a string 4 stretched across a string fixing portion 11 of an instrument body 2 and a neck 3. The relationship between the width W9 of the groove 9 and the width W5 of the saddle 5 is the same as in the first embodiment (see Fig. 4).

[0032] The pickup 6F of the second embodiment has three piezoelectric elements 20A, 20B, and 20C. The three piezoelectric elements 20A, 20B, and 20C include a first piezoelectric element 20A, a second piezoelectric element 20B, and a third piezoelectric element 20C. As shown in Fig. 7, each of the piezoelectric elements 20A, 20B, and 20C has a porous layer 21 and electrode layers 22 and 23 similar to those of the first embodiment. 6, the first piezoelectric element 20A is disposed between the first inner side surface 9a of the groove 9 and the first side surface 5a of the saddle 5, similar to the piezoelectric element 20 of the first embodiment. The thickness direction of the first piezoelectric element 20A is oriented in the arrangement direction of the first inner side surface 9a of the groove 9 and the first side surface 5a of the saddle 5.

[0033] The second piezoelectric element 20B is disposed between the bottom surface 9c of the groove 9 and the lower surface 5c of the saddle 5. The thickness direction of the second piezoelectric element 20B is oriented in the arrangement direction of the bottom surface 9c of the groove 9 and the lower surface 5c of the saddle 5. The bottom surface 9c of the groove 9 and the lower surface 5c of the saddle 5 are aligned in the insertion / removal direction of the saddle 5 relative to the groove 9 (the up-and-down direction in FIG. 6). The third piezoelectric element 20C is disposed between the second inner side surface 9b of the groove 9 and the second side surface 5b of the saddle 5. The thickness direction of the third piezoelectric element 20C is oriented in the arrangement direction of the second inner side surface 9b of the groove 9 and the second side surface 5b of the saddle 5. The thickness direction of the third piezoelectric element 20C may be completely aligned with the thickness direction of the first piezoelectric element 20A, or may be slightly misaligned with respect to the thickness direction of the first piezoelectric element 20A.

[0034] When these three piezoelectric elements 20A, 20B, and 20C are disposed between the groove 9 and the saddle 5, the porous layers 21 (see FIG. 7) of the first piezoelectric element 20A and the third piezoelectric element 20C are preferably compressed in the thickness direction. The degree to which the first piezoelectric element 20A and the third piezoelectric element 20C are compressed is preferably set to satisfy the following three conditions. The first condition is that the first piezoelectric element 20A and the third piezoelectric element 20C are not compressed to their maximum extent when no external force, such as the tension of the string 4, is acting on the saddle 5. The second condition is that contact between the third piezoelectric element 20C and the second inner surface 9b of the groove 9 and the second side surface 5b of the saddle 5 is maintained even when the saddle 5 is moved close to the first inner surface 9a of the groove 9 to compress the first piezoelectric element 20A to its maximum extent. The third condition is that contact between the first piezoelectric element 20A and the first inner surface 9a of the groove 9 and the first side surface 5a of the saddle 5 is maintained even when the saddle 5 is brought close to the second inner surface 9b of the groove 9 and the second piezoelectric element 20B is compressed to the maximum extent.

[0035] The porous layer 21 of the second piezoelectric element 20B disposed between the groove 9 and the saddle 5 needs to be compressed in the thickness direction of the porous layer 21 by the force that the saddle 5 receives from the string 4 when the string 4, which is stretched across at least the string fixing portion 11 of the instrument body 2 and the neck 3, is supported by the tip portion 5T of the saddle 5. In other words, when no external force is acting on the saddle 5, the porous layer 21 of the second piezoelectric element 20B does not need to be compressed.

[0036] 6 and 7, in the pickup 6F of this embodiment, the polarization direction of the porous layer 21 in the third piezoelectric element 20C is opposite to the polarization direction of the porous layer 21 in the first piezoelectric element 20A. The polarization direction of the porous layer 21 in the second piezoelectric element 20B is the same as the polarization direction of the porous layer in the first piezoelectric element 20A. In this embodiment, the porous layers 21 of the first piezoelectric element 20A and the third piezoelectric element 20C have a positive electrode on the groove 9 side and a negative electrode on the saddle 5 side. On the other hand, the porous layer 21 of the second piezoelectric element 20B has a negative electrode on the groove 9 side and a positive electrode on the saddle 5 side. When the porous layer 21 is compressed in its thickness direction, a current flows from the positive electrode to the negative electrode in the porous layer 21. When the porous layer 21 is expanded in its thickness direction, a current flows from the negative electrode to the positive electrode.

[0037] 7, in this embodiment, the first piezoelectric element 20A, the second piezoelectric element 20B, and the third piezoelectric element 20C are integrally formed. Specifically, the porous layers 21 of the first piezoelectric element 20A and the second piezoelectric element 20B, which have the same polarization direction, are integrally formed. On the other hand, the porous layer 21 of the third piezoelectric element 20C, which has a polarization direction different from those of the first and second piezoelectric elements 20A and 20B, is formed separately from the porous layers 21 of the first and second piezoelectric elements 20A and 20B. The first and second piezoelectric elements 20A, 20B and the third piezoelectric element 20C are integrally formed by two electrode layers 22, 23 laminated on both sides of the porous layer 21. Of the two electrode layers 22, 23, the first electrode layer 22 is connected to the negative electrodes of the porous layers 21 of the first and second piezoelectric elements 20A, 20B and the positive electrode of the third piezoelectric element 20C. Of the two electrode layers 22, 23, the second electrode layer 23 is connected to the positive electrodes of the porous layers 21 of the first and second piezoelectric elements 20A, 20B and the negative electrode of the third piezoelectric element 20C.

[0038] The pickup 6F and the stringed instrument of the second embodiment have the same effects as those of the first embodiment. Furthermore, in the pickup 6F and string instrument of the second embodiment, the polarization direction of the porous layer 21 of the third piezoelectric element 20C is opposite to the polarization direction of the porous layer 21 of the first piezoelectric element 20A. Therefore, even if the electrode layers 22, 23 provided on both sides of the porous layer 21 of the first piezoelectric element 20A and the electrode layers 22, 23 provided on both sides of the porous layer 21 of the third piezoelectric element 20C are integrally formed, it is possible to prevent the detection signal output from the first piezoelectric element 20A and the detection signal output from the third piezoelectric element 20C from canceling each other out in response to the movement of the saddle 5. Furthermore, the detection signals output from the first piezoelectric element 20A and the third piezoelectric element 20C are added together in response to the movement of the saddle 5. This point will be described below.

[0039] When the vibration of the string 4 is transmitted to the saddle 5, the saddle 5 vibrates in the longitudinal direction of the string 4 (the direction in which the first inner surface 9a and the second inner surface 9b of the groove 9 are arranged). When the saddle 5 vibrates in this manner, as shown in Fig. 8, when the first piezoelectric element 20A compresses, the third piezoelectric element 20C expands. Also, when the first piezoelectric element 20A expands, the third piezoelectric element 20C compresses. 7, the first electrode layer 22 is connected to the negative electrode of the porous layer 21 of the first piezoelectric element 20A and the positive electrode of the third piezoelectric element 20C. Meanwhile, the second electrode layer 23 is connected to the positive electrode of the porous layer 21 of the first piezoelectric element 20A and the negative electrode of the third piezoelectric element 20C. Therefore, when the first piezoelectric element 20A compresses and the third piezoelectric element 20C expands, a current flows from the second electrode layer 23 to the first electrode layer 22 in both the first and third piezoelectric elements 20A and 20C. Furthermore, when the first piezoelectric element 20A expands and the third piezoelectric element 20C compresses, a current flows from the first electrode layer 22 to the second electrode layer 23 in both the first and third piezoelectric elements 20A and 20C. As a result, the detection signals output from the first piezoelectric element 20A and the third piezoelectric element 20C are added together. By adding together the detection signals output from the first and third piezoelectric elements 20A and 20C, the S / N ratio of the detection signal output from the piezoelectric element 20 in accordance with the movement of the saddle 5 can be further increased.

[0040] Furthermore, in the pickup 6F and stringed instrument of the second embodiment, the polarization direction of the porous layer 21 in the second piezoelectric element 20B is the same as the polarization direction of the porous layer 21 in the first piezoelectric element 20A. Therefore, the detection signals output from the first and second piezoelectric elements 20A and 20B as they compress can be added together. This point will be described below.

[0041] When playing a stringed instrument, for example, pressing the string 4 against the neck 3 with a finger pulls the string 4 toward the neck 3. At this time, as shown in FIG. 8 , the saddle 5 receives force from the string 4 and moves toward the first inner surface 9a and bottom surface 9c of the groove 9. As a result, the first and second piezoelectric elements 20A, 20B located between the first inner surface 5a and bottom surface 5c of the saddle 5 and the groove 9 are compressed. Here, because the polarization directions of the porous layers 21 of the first and second piezoelectric elements 20A, 20B are the same, the detection signals output from the first and second piezoelectric elements 20A, 20B as the first and second piezoelectric elements 20A, 20B are compressed can be added together. By adding together the detection signals output from the first and second piezoelectric elements 20A and 20B, the S / N ratio of the detection signal output from the piezoelectric element 20 in accordance with the movement of the saddle 5 can be further increased.

[0042] Furthermore, in the pickup 6F of the second embodiment, the first piezoelectric element 20A, the second piezoelectric element 20B, and the third piezoelectric element 20C are integrally formed. Therefore, the pickup 6F including these three piezoelectric elements 20A, 20B, and 20C can be more easily installed between the groove 9 and the saddle 5 than when these three piezoelectric elements 20A, 20B, and 20C are formed separately.

[0043] (Third embodiment) Next, a third embodiment of the present invention will be described with reference to Figures 9 and 10. In the following description, components common to those already described will be assigned the same reference numerals and duplicated description will be omitted.

[0044] 9 and 10, in the stringed instrument of the third embodiment, a saddle 5 is inserted into a groove 9 of a bridge 8, as in the first embodiment. The saddle 5 supports a string 4 stretched across a string fixing portion 11 of the instrument body 2 and the neck 3. The relationship between the width W9 of the groove 9 and the width W5 of the saddle 5 is the same as in the first embodiment.

[0045] The pickup 6G of the third embodiment includes a piezoelectric element 20 (first piezoelectric element) similar to that of the first embodiment. The piezoelectric element 20 is disposed between the first inner surface 9a of the groove 9 and the first side surface 5a of the saddle 5 so that the thickness direction of the piezoelectric element 20 faces the arrangement direction of the first inner surface 9a of the groove 9 and the first side surface 5a of the saddle 5. However, in the third embodiment, the first inner surface 9a of the groove 9 and the first side surface 5a of the saddle 5 are located on the string fixing portion 11 side in the longitudinal direction of the string 4. On the other hand, the second inner surface 9b of the groove 9 and the second side surface 5b of the saddle 5 are located on the neck 3 side in the longitudinal direction of the string 4.

[0046] Furthermore, the thickness T20 of the piezoelectric element 20 under no load is smaller than the difference between the width W9 of the groove 9 and the width W5 of the saddle 5. The piezoelectric element 20 is bonded to the first inner surface 9a of the groove 9 and the first side surface 5a of the saddle 5. Therefore, as shown in FIG. 9 , in a state in which the piezoelectric element 20 is simply disposed between the first inner surface 9a of the groove 9 and the first side surface 5a of the saddle 5, the saddle 5 can move in a direction toward the first inner surface 9a of the groove 9 and in a direction away from the first inner surface 9a. This movement of the saddle 5 causes the piezoelectric element 20 to expand and contract in its thickness direction.

[0047] With the saddle 5 and piezoelectric element 20 disposed in the groove 9 as described above, when the string 4 stretched across the string fixing portion 11 of the instrument body 2 and the neck 3 is supported by the tip portion 5T of the saddle 5, the tension of the string 4 pushes the tip portion 5T of the saddle 5 toward the neck 3, as shown in Fig. 10. This causes the saddle 5 to move so as to tilt toward the second inner surface 9b of the groove 9, and the first side surface 5a of the saddle 5 moves away from the first inner surface 9a of the groove 9. As a result, the piezoelectric element 20 is stretched in its thickness direction. The thickness of the piezoelectric element 20 stretched as described above may be, for example, 150% or less of the thickness T20 of the piezoelectric element 20 when no load is applied, but is more preferably, for example, 130% or less. In other words, it is preferable that the amount of stretch of the piezoelectric element 20 due to an external force is small. This is because the smaller the amount of stretch of the piezoelectric element 20, the higher the sensitivity of the piezoelectric element 20.

[0048] In the stringed instrument of the third embodiment configured as described above, vibrations of the strings 4 are transmitted to the piezoelectric element 20 via the saddle 5, causing the porous layer 21 of the piezoelectric element 20 to expand and contract in its thickness direction. This causes the piezoelectric element 20 to output a detection signal (electrical signal) according to the expansion and contraction deformation of the porous layer 21. When the piezoelectric element 20 expands and contracts in response to the string vibration, the piezoelectric element 20 may expand or contract relative to its unloaded state.

[0049] According to the third embodiment, the same effects as those of the first embodiment are achieved. That is, even in the pickup 6G and stringed instrument of the third embodiment, the piezoelectric element 20 is more elastic than a piezoelectric element (e.g., a conventional piezoelectric element) that does not have the porous layer 21. Therefore, even if the thickness T20 of the piezoelectric element 20 under no load does not need to be set with high precision relative to the distance between the first side surface 5a of the saddle 5 and the first inner surface 9a of the groove 9, as in the conventional case, the piezoelectric element 20 can be made to expand and contract in its thickness direction, so that the piezoelectric element 20 can be installed without a gap between the first side surface 5a of the saddle 5 and the first inner surface 9a of the groove 9. In the third embodiment, by bonding the piezoelectric element 20 to the first side surface 5a of the saddle 5 and the first inner surface 9a of the groove 9, the piezoelectric element 20 can be easily installed without a gap between the first side surface 5a of the saddle 5 and the first inner surface 9a of the groove 9. Furthermore, because the amount of expansion and contraction of the piezoelectric element 20 is large, even if the distance between the first side surface 5a of the saddle 5 and the first inner side surface 9a of the groove 9 increases due to string vibration or the like, it is possible to suppress or prevent the piezoelectric element 20 from moving away from the first side surface 5a of the saddle 5 and the first inner side surface 9a of the groove 9. This allows the piezoelectric element 20 placed between the saddle 5 and the groove 9 to expand and contract in accordance with the movement of the saddle 5, and as a result, the piezoelectric element 20 can correctly output a detection signal.

[0050] 10 , in the pickup 6G and stringed instrument of the third embodiment, the piezoelectric element 20 is disposed between the first inner surface 9a of the groove 9 and the first side surface 5a of the saddle 5, with the porous layer 21 stretched in the thickness direction by the tension of the string 4. In this state, when the saddle 5 is displaced in a direction toward the first inner surface 9a of the groove 9 in conjunction with the vibration of the string 4, the porous layer 21 of the piezoelectric element 20 is compressed. Furthermore, when the saddle 5 is displaced in a direction away from the first inner surface 9a of the groove 9, the porous layer 21 of the piezoelectric element 20 is further stretched. This allows the piezoelectric element 20 to detect displacement of the saddle 5 in a direction toward and away from the first inner surface 9a of the groove 9.

[0051] In the third embodiment, the piezoelectric element 20, whose thickness T20 under no load is smaller than the difference between the width W9 of the groove 9 and the width W5 of the saddle 5, may be disposed, for example, between the second inner surface 9b of the groove 9 located on the neck 3 side in the longitudinal direction of the string 4 and the second side surface 5b of the saddle 5. In this case, by tensioning the string 4 across the string fixing portion 11 of the instrument body 2 and the neck 3 and supporting the string 4 on the tip portion 5T of the saddle 5, the tension of the string 4 presses the tip portion 5T of the saddle 5 toward the neck 3. This compresses the piezoelectric element 20 between the groove 9 and the saddle 5. Therefore, the piezoelectric element 20 can be sandwiched between the second inner surface 9b of the groove 9 and the second side surface 5b of the saddle 5 without being glued to the groove 9 or the saddle 5.

[0052] The piezoelectric element 20 of the third embodiment, whose thickness T20 at no load is smaller than the difference between the width W9 of the groove 9 and the width W5 of the saddle 5, may be applied, for example, to the three piezoelectric elements 20A, 20B, and 20C of the second embodiment (particularly, the first and third piezoelectric elements 20A and 20C).

[0053] Although the present invention has been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

[0054] The pickup of the present invention is not limited to application to guitars, but can be applied to at least any stringed instrument in which the strings are supported by a saddle inserted into a groove formed in the body of the instrument. [Explanation of symbols]

[0055] 1...stringed instrument, 2...instrument body, 4...string, 5...saddle, 5a...first side, 5b...second side, 5c...bottom, 6, 6F...pickup, 9...groove, 9a...first inner surface, 9b...second inner surface, 9c...bottom, 20...piezoelectric element (first piezoelectric element), 20A...first piezoelectric element, 20B...second piezoelectric element, 20C...third piezoelectric element, 21...porous layer, T20...thickness of piezoelectric element 20, W5...width of saddle 5, W9...width of groove 9

Claims

1. The instrument itself, Strings and a saddle inserted into a groove formed in the instrument body to support the strings; a pickup having a porous layer that is expandable and contractible in a thickness direction, the pickup including a piezoelectric element that outputs a detection signal in response to the expansion and contraction deformation of the porous layer; The piezoelectric elements include a first piezoelectric element disposed between at least a first inner surface of the groove and a first side surface of the saddle; a width of the groove from a first inner surface of the groove to a second inner surface of the groove facing the first inner surface is larger than a width of the saddle in an arrangement direction of the first inner surface and the second inner surface, a thickness of the first piezoelectric element in the arrangement direction under no load is equal to or greater than a difference between a width of the groove and a width of the saddle; A stringed instrument, wherein the first piezoelectric element is positioned between a first inner surface of the groove and a first side surface of the saddle in a state in which the porous layer is compressed in the thickness direction.

2. The instrument itself, Strings and a saddle inserted into a groove formed in the instrument body to support the strings; a pickup having a porous layer that is expandable and contractible in a thickness direction, the pickup including a piezoelectric element that outputs a detection signal in response to the expansion and contraction deformation of the porous layer; The piezoelectric elements include a first piezoelectric element disposed between at least a first inner surface of the groove and a first side surface of the saddle; a width of the groove from a first inner surface of the groove to a second inner surface of the groove facing the first inner surface is larger than a width of the saddle in an arrangement direction of the first inner surface and the second inner surface, a thickness of the first piezoelectric element in the arrangement direction under no load is smaller than a difference between a width of the groove and a width of the saddle; A stringed instrument, wherein the first piezoelectric element is positioned between a first inner surface of the groove and a first side surface of the saddle in a state in which the porous layer is compressed in the thickness direction.

3. a piezoelectric element having a porous layer that is expandable and contractible in a thickness direction and that outputs a detection signal in response to the expansion and contraction deformation of the porous layer; The piezoelectric element includes a first piezoelectric element disposed at least between a first inner surface of a groove formed in a body of the stringed instrument and a first side surface of a saddle of the stringed instrument inserted into the groove; a width of the groove from a first inner surface of the groove to a second inner surface of the groove facing the first inner surface is larger than a width of the saddle in an arrangement direction of the first inner surface and the second inner surface, a thickness of the first piezoelectric element in the arrangement direction under no load is equal to or greater than a difference between a width of the groove and a width of the saddle; The first piezoelectric element is a pickup that is disposed between a first inner surface of the groove and a first side surface of the saddle in a state in which the porous layer is compressed in the thickness direction.

4. a piezoelectric element having a porous layer that is expandable and contractible in a thickness direction and that outputs a detection signal in response to the expansion and contraction deformation of the porous layer; The piezoelectric element includes a first piezoelectric element disposed at least between a first inner surface of a groove formed in a body of the stringed instrument and a first side surface of a saddle of the stringed instrument inserted into the groove; a width of the groove from a first inner surface of the groove to a second inner surface of the groove facing the first inner surface is larger than a width of the saddle in an arrangement direction of the first inner surface and the second inner surface, a thickness of the first piezoelectric element in the arrangement direction under no load is smaller than a difference between a width of the groove and a width of the saddle; The first piezoelectric element is a pickup that is disposed between a first inner surface of the groove and a first side surface of the saddle in a state in which the porous layer is compressed in the thickness direction.

5. The piezoelectric element includes: the first piezoelectric element disposed between a first inner surface of the groove and a first side surface of the saddle; a second piezoelectric element disposed between the bottom surface of the groove and the lower surface of the saddle; a third piezoelectric element disposed between a second inner surface of the groove and a second side surface of the saddle; 5. The pickup according to claim 3 or 4, wherein:

6. 6. The pickup according to claim 5, wherein the polarization direction of the porous layer of the third piezoelectric element is opposite to the polarization direction of the porous layer of the first piezoelectric element.

7. the first side of the saddle is a surface positioned on the neck side of the stringed instrument, a second side surface of the saddle located on the opposite side from the neck and on the side of a string fixing portion of the instrument body that fixes a first end of a string of a stringed instrument, 7. The pickup according to claim 6, wherein the polarization direction of the porous layer in the second piezoelectric element is the same as the polarization direction of the porous layer in the first piezoelectric element.

8. The pickup according to claim 5 , wherein the first piezoelectric element, the second piezoelectric element, and the third piezoelectric element are integrally formed.

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