Musical performance operation device

Abstract

To generate a detection signal on which fine movement of a movable member used for a musical performance is reflected with high precision.SOLUTION: A musical performance operation device comprises a movable member which is displaced according to musical performance operation, a detected part which is formed of a magnetic body or conductor, and installed at the movable member, and a signal generation unit which generates a detection signal from a reference signal with a low-pass filter using a coil, the filter varying in frequency response with the distance between the detected part and the coil. A high-pass filter includes an input terminal supplied with the reference signal, an output terminal outputting the detection signal, a first capacitive element connected between the input terminal and a connection point, a second capacitive element connected between the connection point and the output terminal, and coils including a first coil connected to the connection point and a second coil connected to the output terminal. A magnetic field generated by the first coil and a magnetic field generated by the second coil are in mutually opposite directions.SELECTED DRAWING: Figure 15

Description

Technical Field

[0001] The present disclosure relates to a performance operation device used for performance.

Background Art

[0002] For example, various techniques for detecting the displacement of movable members such as keys in a keyboard instrument have been proposed conventionally. Patent Document 1 discloses a configuration for detecting the position of each key by using a coil installed on the frame of a keyboard instrument and a metal plate installed on each key. In the above configuration, when the metal plate is displaced by pressing a key, the current flowing through the coil changes. By detecting the current flowing through the coil, a detection signal representing the presence or absence of pressing the key is generated.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the technique of Patent Document 1, it is not actually easy to sufficiently change the current of the coil due to the displacement of the metal plate by pressing the key. Therefore, it is difficult to generate a detection signal that accurately reflects the minute displacement of the key. In view of the above circumstances, one aspect of the present disclosure aims to generate a detection signal that accurately reflects the minute displacement of a movable member used for performance.

Means for Solving the Problems

[0005] In order to solve the above problems, a performance operation device according to one aspect of the present disclosure includes a movable member that is displaced according to a performance action, a detected portion formed of a magnetic material or a conductor and installed on the movable member, and a signal generation unit that generates a detection signal from a reference signal by a filter using a coil, the signal generation unit being configured such that a frequency response of the filter changes according to a distance between the detected portion and the coil.

Brief Description of the Drawings

[0006]

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Mode for Carrying Out the Invention

[0007] A: First Embodiment FIG. 1 is a block diagram illustrating the configuration of a keyboard instrument 100 according to the first embodiment of the present disclosure. The keyboard instrument 100 is an electronic musical instrument including a keyboard 10, a detection system 20, an information processing device 30, and a sound emission device 40. The keyboard 10 is composed of a plurality of keys 12 including white keys and black keys. Each of the plurality of keys 12 is a movable member that is displaced according to a playing operation by a user. The detection system 20 detects the displacement of each key 12. The information processing device 30 generates an acoustic signal V according to the result of detection by the detection system 20. The acoustic signal V is a signal representing a musical tone of a pitch corresponding to the key 12 operated by the user. The sound emission device 40 emits the sound represented by the acoustic signal V. For example, a speaker or headphones are used as the sound emission device 40.

[0008] FIG. 2 is a block diagram illustrating a specific configuration of the keyboard instrument 100 by focusing on one key 12 of the keyboard 10. The keyboard instrument 100 includes a support member 14. The support member 14 is a structure (frame) that supports each element of the keyboard instrument 100. The support member 14 includes a first surface 141 and a second surface 142. The first surface 141 is a surface facing the keyboard 10. The second surface 142 is a surface on the opposite side of the first surface 141. Each key 12 of the keyboard 10 is supported by the support member 14 with a support portion 13 installed on the first surface 141 as a fulcrum. An elastic body 15 is installed between the bottom surface of the key 12 and the first surface 141 of the support member 14. The elastic body 15 biases the key 12 upward in the vertical direction. The end portion 121 of each key 12 is displaced in the vertical direction by the user's key pressing and key releasing.

[0009] A connecting member 123 is installed on the bottom surface of the key 12. The connecting member 123 is a portion that protrudes downward in the vertical direction from the bottom surface of the key 12. The connecting member 123 penetrates a through hole 143 formed in the support member 14. That is, the connecting member 123 protrudes downward in the vertical direction from the second surface 142 of the support member 14. Further, a support portion 144 is installed on the second surface 142 of the support member 14. The support portion 144 protrudes downward in the vertical direction from the second surface 142.

[0010] A tuning weight 50 is installed for each key 12 in the space on the opposite side of the key 12 across the support member 14. The tuning weight 50 is a hammer weight for adjusting the operating feeling of the key 12 by the user. The tuning weight 50 is formed of a magnetic body (ferromagnetic body) or a conductor. Specifically, the tuning weight 50 is formed of a magnetic material such as iron or ferrite, for example.

[0011] The adjusting weight 50 is a structure in which a rotating part 51 and a load part 52 are integrally formed. The rotating part 51 is a columnar (for example, cylindrical or prismatic) part extending between a first end e1 and a second end e2. The load part 52 is a weight-shaped part formed with a predetermined weight and is installed at the first end e1 of the rotating part 51. The second end e2 is supported by the connecting member 123. The adjusting weight 50 is rotatably supported by the support part 144 between the first end e1 and the second end e2. With the above configuration, the adjusting weight 50 rotates about the support part 144 as a fulcrum in accordance with the displacement of the key 12. That is, the position of the load part 52 in the vertical direction changes in conjunction with the displacement of the key 12. Specifically, the load part 52 moves upward in the vertical direction by pressing the key and moves downward in the vertical direction by releasing the key. The user can perceive an appropriate sense of resistance when pressing the key by moving the load part 52 in conjunction with the displacement of the key 12 as described above.

[0012] The detection system 20 generates a detection signal D at a level corresponding to the position Z of the end portion 121 in the vertical direction for each of the plurality of keys 12. The position Z is the amount of displacement of the end portion 121 based on the position of the end portion 121 in a state where no load acts on the key 12.

[0013] The detection system 20 includes a signal generation unit 60 and a signal processing circuit 21. The signal generation unit 60 is installed for each key 12 on the second surface 142 of the support member 14. The signal generation unit 60 includes a coil 61. The signal generation unit 60 and the load part 52 of the adjusting weight 50 face each other with a space therebetween in the vertical direction. The distance between the signal generation unit 60 and the load part 52 (the distance between the coil 61 and the load part 52) changes in accordance with the position Z of the end portion 121 in the key 12.

[0014] FIG. 3 is a circuit diagram illustrating the electrical configuration of the signal generation unit 60. The signal generation unit 60 is a filter including an input terminal T1, an output terminal T2, a coil 61, and a capacitive element 62. The coil 61 is connected between the input terminal T1 and the output terminal T2. The capacitive element 62 is connected between the output terminal T2 and the ground line. The signal generation unit 60 is a low-pass filter (LPF: Low-pass filter) that suppresses a band component exceeding the cut-off frequency Fc in the signal supplied to the input terminal T1. The cut-off frequency Fc is set to a numerical value (Fc = 1 / (2π√LC)) corresponding to the inductance L of the coil 61 and the capacitance coefficient C of the capacitive element 62.

[0015] The signal processing circuit 21 in FIG. 2 generates a detection signal D at a level corresponding to the distance between the coil 61 and the load unit 52. FIG. 4 is a block diagram illustrating the specific configuration of the signal processing circuit 21. The signal processing circuit 21 includes a supply circuit 22 and an output circuit 23. The supply circuit 22 supplies a reference signal Q to each of the plurality of signal generation units 60. The reference signal Q is a voltage signal whose level varies at a frequency Fref. For example, a periodic signal having an arbitrary waveform such as a sine wave is used as the reference signal Q. The frequency Fref of the reference signal Q is, for example, about 1 MHz. The supply circuit 22 supplies the reference signal Q to each signal generation unit 60 in a time-division manner. Specifically, the supply circuit 22 is a demultiplexer that sequentially selects each of the plurality of signal generation units 60 and supplies the reference signal Q to the selected signal generation unit 60. That is, the reference signal Q is supplied to each of the plurality of signal generation units 60 in a time-division manner. Note that the period of the reference signal Q is sufficiently shorter than the time length of the period during which the supply circuit 22 selects one signal generation unit 60.

[0016] As illustrated in FIG. 3, the reference signal Q is supplied to the input terminal T1 of the signal generation unit 60. The signal generation unit 60 generates a detection signal d from the reference signal Q by a filter using the coil 61. The detection signal d is a periodic signal whose level varies at the same period as the reference signal Q.

[0017] FIG. 5 shows the frequency response X (X1, X2) of the signal generation unit 60. The frequency response X1 is the frequency response X of the signal generation unit 60 when the load unit 52 is in the state closest to the coil 61 (hereinafter referred to as the "close state"). On the other hand, the frequency response X2 is the frequency response X of the signal generation unit 60 when the load unit 52 is in the state farthest from the coil 61 (hereinafter referred to as the "separated state").

[0018] The inductance L of the coil 61 decreases as the load unit 52 approaches. Therefore, the frequency response X of the signal generation unit 60 changes according to the distance between the load unit 52 and the coil 61. Specifically, the cut-off frequency Fc in the frequency response X changes according to the distance between the load unit 52 and the coil 61. For example, as the load unit 52 approaches the coil 61, the cut-off frequency Fc increases. Therefore, the gain G with respect to the frequency Fref of the reference signal Q changes according to the distance between the load unit 52 and the coil 61. For example, in the close state, the gain G with respect to the frequency Fref is the numerical value g1, while in the separated state, the gain G with respect to the frequency Fref is the numerical value g2 which is lower than the numerical value g1.

[0019] As understood from the above description, a detection signal d of the amplitude level δ according to the distance between the load unit 52 and the coil 61 is output from the output terminal T2 of the signal generation unit 60. That is, the load unit 52 is used as the detected unit detected by the detection system 20.

[0020] The frequency band B in FIG. 5 is a frequency band in which the gain G changes with respect to the frequency among the frequency bands exceeding the cut-off frequency Fc. The frequency Fref of the reference signal Q is located within the range W between the frequency fL and the frequency fH. The frequency fL is the lower limit value of the frequency band B in the frequency response X2 in the separated state, and corresponds to the cut-off frequency Fc in the frequency response X2. The frequency fH is the upper limit value of the frequency band B in the frequency response X1 in the close state, and corresponds to the frequency at which the gain G becomes 0 in the frequency response X1.

[0021] For example, the frequency Fref of the reference signal Q and the inductance coefficient L of the coil 61 and the capacitance coefficient C of the capacitance element 62 are set so that the frequency Fref of the reference signal Q is included in the frequency band B in both the approaching state and the separating state. That is, within the range W, the frequency Fref of the reference signal Q is located within the overlapping range wM of the frequency band B in the frequency response X1 and the frequency band B in the frequency response X2. However, a configuration in which the frequency Fref is located within the range wL where the gain G is constant (G = 1) in the frequency response X1 within the range W, or a configuration in which the frequency Fref is located within the range wH where the gain G is constant (G = 0) in the frequency response X2 within the range W is also assumed.

[0022] The output circuit 23 in FIG. 4 generates the detection signal D by arranging the detection signals d sequentially output from each of the plurality of signal generation units 60 on the time axis. That is, the detection signal D is a voltage signal with an amplitude level δ corresponding to the distance between the load portion 52 and the coil 61 at each key 12. Since the distance between the load portion 52 and the coil 61 is linked to the position Z of each key 12 as described above, the detection signal D can be expressed as a signal corresponding to the position Z of each of the plurality of keys 12. The detection signal D generated by the output circuit 23 is supplied to the information processing apparatus 30.

[0023] The information processing apparatus 30 in FIG. 2 analyzes the position Z of each key 12 by analyzing the detection signal D supplied from the signal processing circuit 21. The information processing apparatus 30 is realized by a computer system including a control device 31, a storage device 32, an A / D converter 33, and a sound source circuit 34. The A / D converter 33 converts the detection signal D supplied from the signal processing circuit 21 from analog to digital.

[0024] The control device 31 is composed of one or more processors that control each element of the keyboard instrument 100. For example, the control device 31 is composed of one or more types of processors such as a CPU (Central Processing Unit), SPU (Sound Processing Unit), DSP (Digital Signal Processor), FPGA (Field Programmable Gate Array), or ASIC (Application Specific Integrated Circuit).

[0025] The storage device 32 is one or more memories that store the programs executed by the control device 31 and the data used by the control device 31. The storage device 32 is composed of a known recording medium such as a magnetic recording medium or a semiconductor recording medium, for example. Note that the storage device 32 may be configured by a combination of multiple types of recording media. Also, a portable recording medium that can be attached to and detached from the keyboard instrument 100, or an external recording medium (e.g., online storage) that the keyboard instrument 100 can communicate with may be used as the storage device 32.

[0026] The control device 31 analyzes the position Z of each key 12 by analyzing the detected signal D after conversion by the A / D converter 33. Also, the control device 31 instructs the sound source circuit 34 to generate a musical sound corresponding to the position Z of each key 12. The sound source circuit 34 generates an acoustic signal V representing the musical sound instructed by the control device 31. That is, the sound source circuit 34 generates an acoustic signal V corresponding to the amplitude level δ of the detected signal D. For example, the volume of the acoustic signal V is controlled according to the amplitude level δ. When the acoustic signal V is supplied from the sound source circuit 34 to the sound emitting device 40, a musical sound corresponding to the playing operation (key pressing or key release of each key 12) by the user is emitted from the sound emitting device 40.

[0027] FIG. 6 is a plan view illustrating the configuration of the coil 61 in the signal generation unit 60, and FIG. 7 is a cross-sectional view taken along line a-a in FIG. 6. The coil 61 is constituted by, for example, a wiring pattern formed on the surface of a wiring board. The coil 61 includes a first portion 611 and a second portion 612. The first portion 611 and the second portion 612 are formed in different regions in a plan view. Specifically, the first portion 611 and the second portion 612 are adjacent to each other along the longitudinal direction of the key 12.

[0028] The first portion 611 is a spiral portion that spirals from the inner peripheral side end Ea1 to the outer peripheral side end Ea2. Similarly, the second portion 612 is a spiral portion that spirals from the inner peripheral side end Eb1 to the outer peripheral side end Eb2. The end Ea2 is connected to the input terminal T1, and the end Eb2 is connected to the output terminal T2. Also, the end Ea1 and the end Eb1 are connected to each other via a relay wiring 614.

[0029] As understood from the above description, the direction of the current flowing in the first portion 611 and the direction of the current flowing in the second portion 612 are opposite. Specifically, when a current in the direction C1 flows in the first portion 611, a current in the direction C2 opposite to the direction C1 flows in the second portion 612. Therefore, as illustrated in FIG. 7, magnetic fields in opposite directions are generated in the first portion 611 and the second portion 612. That is, a magnetic field is formed from one of the first portion 611 and the second portion 612 toward the other. According to the above configuration, the diffusion of the magnetic field across each adjacent key 12 is reduced. Therefore, a detection signal D that accurately reflects the position Z of each of the plurality of keys 12 is generated.

[0030] The load portion 52 of the adjustment weight 50 faces both the first portion 611 and the second portion 612 of the coil 61. Specifically, the central axis of the first portion 611 and the central axis of the second portion 612 overlap the load portion 52. According to the above configuration, the load portion 52 is affected by both the magnetic field formed by the first portion 611 and the magnetic field formed by the second portion 612. Therefore, the above-described effect of being able to detect the detection signal D that accurately reflects the minute displacement of the key 12 is remarkable.

[0031] As described above, in the first embodiment, since the frequency response X of the signal generation unit 60 changes according to the distance between the load portion 52 and the coil 61, a detection signal D of the amplitude level δ corresponding to the distance is generated. That is, a detection signal D corresponding to the position Z of each key 12 is generated. In the above configuration, since the amplitude level δ of the detection signal D changes according to the frequency response X of the signal generation unit 60, it is possible to greatly change the level of the detection signal D with respect to the displacement of the key 12. Therefore, there is an advantage that a detection signal D reflecting minute displacements of each key 12 with high accuracy can be generated.

[0032] Particularly in the first embodiment, the distance between the load portion 52 and the coil 61 in the direction of the central axis of the coil 61 changes according to the displacement of the key 12. Therefore, compared with a configuration in which the load portion 52 and the coil 61 relatively move in a plane perpendicular to the central axis of the coil 61 (that is, a configuration in which the distance between the load portion 52 and the coil 61 in the direction of the central axis of the coil 61 does not change), it is possible to greatly change the amplitude level δ of the detection signal D with respect to the displacement of each key 12.

[0033] Also, in the first embodiment, the adjustment weight 50 (load portion 52) for adjusting the operation feeling of the key 12 by the user is also used as a detected portion for detecting the position Z of the key 12. Therefore, there is also an advantage that the configuration of the keyboard instrument 100 is simplified as compared with a configuration in which a detected portion is provided separately from the adjustment weight 50.

[0034] B: Second Embodiment The second embodiment of the present disclosure will be described. Note that for elements having the same functions as those in the first embodiment in each configuration exemplified below, the reference numerals used in the description of the first embodiment are reused and detailed descriptions thereof are appropriately omitted.

[0035] FIG. 8 is a circuit diagram illustrating the electrical configuration of the signal generation unit 60 in the second embodiment. The signal generation unit 60 of the second embodiment is a filter including an input terminal T1, an output terminal T2, a coil 61, and a resistance element 63. The coil 61 is connected between the input terminal T1 and the output terminal T2. Similar to the example shown in FIG. 6, the coil 61 includes a first portion 611 and a second portion 612 in which the directions of the currents are opposite to each other. The resistance element 63 is connected between the output terminal T2 and the ground line.

[0036] Similar to the first embodiment, the signal generation unit 60 is a low-pass filter that suppresses components of the reference signal Q supplied to the input terminal T1 that exceed the cut-off frequency Fc. The cut-off frequency Fc is set to a numerical value (Fc = R / (2πL)) corresponding to the inductance L of the coil 61 and the electrical resistance R of the resistance element 63. The same effect as that of the first embodiment is achieved also in the second embodiment.

[0037] C: Third Embodiment FIG. 9 is a circuit diagram illustrating the electrical configuration of the signal generation unit 60 in the third embodiment. The signal generation unit 60 of the third embodiment is a filter including an input terminal T1, an output terminal T2, a coil 61, and a capacitance element 62. The capacitance element 62 is connected between the input terminal T1 and the output terminal T2. The coil 61 is connected between the output terminal T2 and the ground line. Similar to the example shown in FIG. 6, the coil 61 includes a first portion 611 and a second portion 612 in which the directions of the currents are opposite to each other.

[0038] FIG. 10 shows the frequency response X (X1, X2) of the signal generation unit 60 in the third embodiment. The frequency response X1 in the approaching state and the frequency response X2 in the separated state are shown together in FIG. 10. The signal generation unit 60 is a high-pass filter (HPF: High-pass filter) that suppresses band components of the reference signal Q supplied to the input terminal T1 that are below the cut-off frequency Fc. The cut-off frequency Fc is set to a numerical value (Fc = 1 / (2π√LC)) corresponding to the inductance L of the coil 61 and the capacitance coefficient C of the capacitance element 62.

[0039] The cut-off frequency Fc in the frequency response X changes according to the distance between the load portion 52 and the coil 61. For example, as the load portion 52 approaches the coil 61, the cut-off frequency Fc of the signal generation unit 60 increases. Therefore, the gain G with respect to the frequency Fref of the reference signal Q changes according to the distance between the load portion 52 and the coil 61. For example, in the approaching state, the gain G with respect to the frequency Fref is the numerical value g1, while in the separated state, the gain G with respect to the frequency Fref is a numerical value g2 that exceeds the numerical value g1. Therefore, a detection signal d of the amplitude level δ corresponding to the distance between the load portion 52 and the coil 61 is output from the output terminal T2 of the signal generation unit 60. The same effects as those of the first embodiment are also achieved in the third embodiment.

[0040] The frequency band B in FIG. 10 is a range in the frequency band below the cut-off frequency Fc where the gain G changes with respect to the frequency. The frequency Fref of the reference signal Q is located within a range W between the frequency fL and the frequency fH. The frequency fL is the lower limit value of the frequency band B in the frequency response X2 in the separated state and corresponds to the frequency at which the gain G becomes 0 in the frequency response X2. The frequency fH is the upper limit value of the frequency band B in the frequency response X1 in the approaching state and corresponds to the cut-off frequency Fc in the frequency response X1.

[0041] For example, the frequency Fref, the inductance coefficient L of the coil 61, and the capacitance coefficient C of the capacitive element 62 are set so that the frequency Fref of the reference signal Q is included in the frequency band B in both the approaching state and the separated state. That is, within the range W, the frequency Fref of the reference signal Q is located within a range wM where the frequency band B in the frequency response X1 and the frequency band B in the frequency response X2 overlap each other. However, a configuration in which the frequency Fref is located within a range wL where the gain G is constant (G = 0) in the frequency response X1 within the range W, or a configuration in which the frequency Fref is located within a range wH where the gain G is constant (G = 1) in the frequency response X2 within the range W is also assumed.

[0042] D: Fourth Embodiment FIG. 11 is a circuit diagram illustrating the electrical configuration of the signal generation unit 60 in the fourth embodiment. The signal generation unit 60 of the fourth embodiment is a filter including an input terminal T1, an output terminal T2, a coil 61, a capacitive element 62, a resistive element 63A, and a resistive element 63B. The resistive element 63A is connected between the input terminal T1 and the output terminal T2. The coil 61, the capacitive element 62, and the resistive element 63B are connected between the output terminal T2 and the ground line. Similar to the example illustrated in FIG. 6, the coil 61 includes a first portion 611 and a second portion 612 in which the directions of current are opposite to each other.

[0043] FIG. 12 shows the frequency response X(X1, X2) of the signal generation unit 60 in the fourth embodiment. The frequency response X1 in the approaching state and the frequency response X2 in the separated state are shown together in FIG. 12. The signal generation unit 60 of the fourth embodiment is a band elimination filter (BEF) that suppresses components in the frequency band (stop band) B of the reference signal Q. Specifically, the signal generation unit 60 is a notch filter in which the frequency band B is sufficiently narrow.

[0044] The frequency response X of the signal generation unit 60 changes according to the distance between the load unit 52 and the coil 61. Specifically, the position of the frequency band B on the frequency axis changes according to the distance. For example, as the load unit 52 approaches the coil 61, the frequency band B of the signal generation unit 60 moves to the high-frequency side. Therefore, the gain G with respect to the frequency Fref of the reference signal Q changes according to the distance between the load unit 52 and the coil 61. For example, in the approaching state, the gain G with respect to the frequency Fref is the numerical value g1, while in the separated state, the gain G with respect to the frequency Fref is a numerical value g2 that exceeds the numerical value g1. Therefore, similarly to the first embodiment, the detection signal d of the amplitude level δ corresponding to the distance between the load unit 52 and the coil 61 is output from the output terminal T2 of the signal generation unit 60. Note that the frequency Fref, the inductance coefficient L of the coil 61, and the capacitance coefficient C of the capacitive element 62 are set so that the frequency Fref of the reference signal Q is included in the frequency band b in both the approaching state and the separated state. The frequency band b is a range in which the gain G increases with respect to the frequency within the frequency band B. Note that the frequency band b may be a range in which the gain G decreases with respect to the frequency. Also, the frequency Fref of the reference signal Q may be set within a range where the gain G is constant in one of the frequency responses X1 and X2.

[0045] In the fourth embodiment, the same effects as those of the first embodiment are realized. The band-stop filter is characterized in that the gradient of the gain G with respect to the frequency is steeper than that of the low-pass filter or the high-pass filter. Therefore, according to the fourth embodiment, it is easier to secure the change amount of the gain G (and thus the change amount of the amplitude level δ) between the approaching state and the separated state compared to the first embodiment. That is, there is an advantage that the detection signal D reflecting the minute displacement of each key 12 with high accuracy can be generated.

[0046] E: Fifth Embodiment FIG. 13 is a circuit diagram illustrating the electrical configuration of the signal generation unit 60 in the fifth embodiment. The signal generation unit 60 of the fifth embodiment is a low-pass filter including an input terminal T1, an output terminal T2, a coil 61A, a coil 61B, a capacitive element 62A, and a capacitive element 62B. Specifically, the signal generation unit 60 of the fifth embodiment has a configuration in which a plurality of stages (specifically, two stages) of the low-pass filter illustrated in the first embodiment are connected to each other.

[0047] The coil 61A and the coil 61B are connected between the input terminal T1 and the output terminal T2. Specifically, the coil 61A is connected between the input terminal T1 and the connection point N, and the coil 61B is connected between the connection point N and the output terminal T2. The coil 61A is the first portion 611 illustrated in FIG. 6, and the coil 61B is the second portion 612 illustrated in FIG. 6. That is, the direction of the current flowing through the coil 61A and the direction of the current flowing through the coil 61B are opposite to each other. As described in the above example, the coil 61A and the coil 61B correspond to the single coil 61 illustrated in the first embodiment. The capacitive element 62A is connected between the connection point N and the ground line, and the capacitive element 62B is connected between the output terminal T2 and the ground line.

[0048] FIG. 14 shows the frequency response X (X1, X2) of the signal generation unit 60 in the fifth embodiment. The frequency response X1 in the approaching state and the frequency response X2 in the separated state are shown together in FIG. 14.

[0049] As understood from FIG. 14, in the fifth embodiment in which the signal generation unit 60 is configured by a multi-stage low-pass filter, the gradient of the gain G with respect to the frequency is steeper than that in the first embodiment in which the signal generation unit 60 is configured by a single low-pass filter. Therefore, according to the fifth embodiment, it is easier to ensure the change amount ΔG of the gain G (and thus the change amount of the amplitude level δ) between the approaching state and the separated state as compared with the first embodiment. According to the above configuration, there is an advantage that the detection signal D reflecting the minute displacement of each key 12 with high accuracy can be generated.

[0050] F: Sixth Embodiment FIG. 15 is a circuit diagram illustrating the electrical configuration of the signal generation unit 60 in the sixth embodiment. The signal generation unit 60 of the sixth embodiment is a high-pass filter including an input terminal T1, an output terminal T2, a coil 61A, a coil 61B, a capacitive element 62A, and a capacitive element 62B. Specifically, the signal generation unit 60 of the fifth embodiment has a configuration in which a plurality of stages (specifically, two stages) of the high-pass filter illustrated in the third embodiment are connected to each other.

[0051] The capacitive element 62A and the capacitive element 62B are connected between the input terminal T1 and the output terminal T2. Specifically, the capacitive element 62A is connected between the input terminal T1 and the connection point N, and the capacitive element 62B is connected between the connection point N and the output terminal T2. The coil 61A is connected between the connection point N and the ground wire. The coil 61B is connected between the output terminal T2 and the ground wire. The coil 61A is the first part 611 illustrated in FIG. 6, and the coil 61B is the second part 612 illustrated in FIG. 6. That is, the direction of the current flowing through the coil 61A and the direction of the current flowing through the coil 61B are opposite to each other. As described in the above example, the coils 61A and 61B correspond to the single coil 61 illustrated in the first embodiment.

[0052] FIG. 16 shows the frequency response X (X1, X2) of the signal generation unit 60 in the sixth embodiment. The frequency response X1 in the approaching state and the frequency response X2 in the separated state are shown together in FIG. 16.

[0053] As understood from FIG. 16, in the sixth embodiment in which the signal generation unit 60 is configured by a multi-stage high-pass filter, the gradient of the gain G with respect to frequency is steeper than that in the third embodiment in which the signal generation unit 60 is configured by a single high-pass filter. Therefore, according to the sixth embodiment, it is easier to secure the change amount ΔG of the gain G (and thus the change amount of the amplitude level δ) between the approaching state and the separated state as compared with the third embodiment. According to the above configuration, there is an advantage that the detection signal D that accurately reflects the minute displacement of each key 12 can be generated.

[0054] In FIGS. 13 and 15, a configuration is illustrated in which the first portion 611 is used as the coil 61A and the second portion 612 is used as the coil 61B. However, each of the coil 61A and the coil 61B may be constituted by a coil 61 including the first portion 611 and the second portion 612.

[0055] G: Modification Specific modified aspects added to each of the aspects illustrated above are exemplified below. Two or more aspects arbitrarily selected from the following examples may be appropriately combined within a non - conflicting range.

[0056] (1) In each of the above - mentioned forms, the hammer weight connected to the key 12 via the connecting member 123 is exemplified as the adjusting weight 50, but the adjusting weight 50 is not limited to the above examples. For example, as illustrated in FIG. 17, a counterweight directly installed on the key 12 may be used as the adjusting weight 50. The adjusting weight 50 is formed of, for example, a magnetic material or a conductor. In the configuration of FIG. 17, the signal generation unit 60 is installed on the first surface 141 of the support member 14. The distance between the adjusting weight 50 and the signal generation unit 60 changes according to the position Z of the key 12. Therefore, similar to each of the above - mentioned forms, a detection signal D corresponding to the position Z of each key 12 is generated by the signal processing circuit 21.

[0057] (2) In each of the above - mentioned forms, the adjusting weight 50 for adjusting the operating feel of each key 12 is also used as a detected part for detecting the position Z of the key 12, but a configuration in which an element constituting the keyboard instrument 100 is also used as a detected part is not essential. That is, a detected part may be installed separately from the elements necessary for the keyboard instrument 100.

[0058] For example, as illustrated in FIG. 18, a coil 55 installed on the key 12 may be used as the detected part. The coil 55 is installed on the bottom surface of the key 12 so as to face the coil 61 of the signal generation unit 60 installed on the first surface 141 of the support member 14. The coil 55 is constituted by, for example, a wiring pattern formed of a magnetic material or a conductor on the surface of a wiring board, and constitutes a resonance circuit that resonates by mutual induction with the coil 61.

[0059] FIG. 19 is a plan view illustrating the configuration of the coil 55. The coil 55 includes a first portion 551 and a second portion 552. The first portion 551 and the second portion 552 are formed in different regions in a plan view. Specifically, the first portion 551 and the second portion 552 are adjacent to each other along the longitudinal direction of the key 12.

[0060] The first portion 551 is a spiral portion that turns from the inner peripheral side end Ec1 to the outer peripheral side end Ec2. Similarly, the second portion 552 is a spiral portion that turns from the inner peripheral side end Ed1 to the outer peripheral side end Ed2. The end Ec2 and the end Ed2 are connected to each other. Further, the end Ec1 and the end Ed1 are connected to each other via the relay wiring 553.

[0061] In the above configuration, an induced current is generated in the coil 55 by electromagnetic induction due to the magnetic field generated in the coil 61 by the supply of the reference signal Q. Therefore, a magnetic field in a direction that cancels the change in the magnetic field of the coil 61 is generated in the coil 55. The magnetic field generated in the coil 61 changes according to the distance between the coil 55 and the coil 61. Therefore, a detection signal d with an amplitude level δ corresponding to the distance between the coil 55 and the coil 61 is output from the output terminal T2 of the signal generation unit 60. That is, similar to the above-described embodiments, a detection signal D corresponding to the position Z of the key 12 is generated.

[0062] As understood from the example of FIG. 19, the direction of the current flowing in the first portion 551 and the direction of the current flowing in the second portion 552 are opposite. Therefore, magnetic fields in opposite directions are generated in the first portion 551 and the second portion 552. That is, a magnetic field is formed from one of the first portion 551 and the second portion 552 toward the other. According to the above configuration, the diffusion of the magnetic field across the adjacent keys 12 is reduced. Therefore, a detection signal D that accurately reflects the position Z of each of the plurality of keys 12 is generated.

[0063] (3) In each of the above-described embodiments, a configuration for detecting the displacement of the key 12 of the keyboard instrument 100 has been exemplified. However, the movable member whose displacement is detected by the detection system 20 is not limited to the key 12. Specific embodiments of the movable member are exemplified below.

[0064] [Aspect A] FIG. 20 is a schematic diagram of a configuration in which the detection system 20 is applied to the string striking mechanism 91 of the keyboard instrument 100. The string striking mechanism 91 is an action mechanism that strikes a string (not shown) in conjunction with the displacement of each key 12 of the keyboard 10, similar to an acoustic piano. Specifically, the string striking mechanism 91 includes, for each key 12, a hammer 911 that can strike the string by rotation, and a transmission mechanism 912 (such as a wippen, jack, repetition lever, etc.) that rotates the hammer 911 in conjunction with the displacement of the key 12. In the above configuration, the detection system 20 detects the displacement of the hammer 911. Specifically, a detected portion 54 formed of a magnetic body or a conductor is installed on the hammer 911 (such as the hammer shank). On the other hand, the signal generation unit 60 is installed on the support member 913. The support member 913 is a structure that supports the string striking mechanism 91, for example. Also, the detected portion 54 may be installed on a member other than the hammer 911 in the string striking mechanism 91.

[0065] [Aspect B] FIG. 21 is a schematic diagram of a configuration in which the detection system 20 is applied to the pedal mechanism 92 of the keyboard instrument 100. The pedal mechanism 92 includes a pedal 921 that is operated by the user's foot, a support member 922 that supports the pedal 921, and an elastic body 923 that biases the pedal 921 upward in the vertical direction. In the above configuration, the detection system 20 detects the displacement of the pedal 921. Specifically, the detected portion 54 is installed on the bottom surface of the pedal 921. On the other hand, the signal generation unit 60 is installed on the support member 922 so as to face the detected portion 54. Note that the instrument in which the pedal mechanism 92 is used is not limited to the keyboard instrument 100. For example, a pedal mechanism 92 having a similar configuration is used in any instrument such as a percussion instrument.

[0066] As can be understood from the above examples, the object of detection by the detection system 20 is generally expressed as a movable member that is displaced in response to a performance action. The movable member includes performance operators such as the key 12 or pedal 921 that are directly operated by the user, as well as structures such as the hammer 911 that are displaced in conjunction with the operation of the performance operator. However, the movable member in this disclosure is not limited to a member that is displaced in response to a performance action. In other words, the movable member is generally expressed as a member that can be displaced regardless of the trigger that causes the displacement.

[0067] (4) In each of the above-described embodiments, the keyboard instrument 100 includes the sound source circuit 34. However, in a configuration in which the keyboard instrument 100 includes a sound generating mechanism such as a string striking mechanism 91, the sound source circuit 34 may be omitted. The detection system 20 is used to record the performance of the keyboard instrument 100.

[0068] As can be understood from the above description, the present disclosure is also specified as a device (performance operation device) that controls musical tones by outputting operation signals corresponding to performance actions to the sound source circuit 34 or the sound generation mechanism. In addition to musical instruments (keyboard instruments 100) equipped with the sound source circuit 34 or the sound generation mechanism as exemplified in each of the above-mentioned forms, the concept of a performance operation device includes devices that do not have a sound source circuit 34 or a sound generation mechanism (for example, a MIDI controller or the above-mentioned pedal mechanism 92). In other words, the performance operation device in the present disclosure is comprehensively expressed as a device that a performer (operator) operates for performance.

[0069] (5) In each of the above-described embodiments, the coil 61 includes the first portion 611 and the second portion 612. However, the coil 61 does not necessarily have to be formed of two coils. The coil 61 may be formed of one coil (for example, only one of the first portion 611 and the second portion 612).

[0070] (6) In each of the above-described embodiments, an example configuration has been illustrated in which the sound source circuit 34 generates an acoustic signal V according to the position Z of the key 12. However, the control device 31 may realize the function of the sound source circuit 34 by executing a program (sound source software, for example) stored in the storage device 32. An element (the sound source circuit 34 or the control device 31) that generates an acoustic signal V representing a sound according to the level of the detection signal D is comprehensively expressed as a "sound control unit".

[0071] (7) In each of the above-described embodiments, an example configuration has been illustrated in which the entire adjustment weight 50 is formed of a magnetic material. However, the configuration of the adjustment weight 50 is not limited to the above examples. For example, the adjustment weight 50 may be configured by installing a detected portion formed of a magnetic material or a conductive material on a base formed of an insulating material such as a resin material or wood. The detected portion may be integrally formed with the base, for example, or may be fixed to the base with an adhesive or the like.

[0072] (8) In each of the above-described embodiments, an example configuration has been illustrated in which the distance between the coil 61 and the detected portion changes according to the playing operation. However, instead of the above configuration, a configuration in which the area where the coil 61 and the detected portion face each other (hereinafter referred to as the "opposing area") changes according to the playing operation is also assumed. That is, in the present disclosure, any configuration in which the distance or the opposing area between the coil 61 and the detected portion changes according to the playing operation and the frequency response of the filter changes due to the change is acceptable.

[0073] H: Supplementary Note From the embodiments exemplified above, for example, the following configurations can be grasped.

[0074] A performance operation device according to one aspect (Aspect 1) of the present disclosure includes a movable member that is displaced according to a performance operation, a detected portion formed of a magnetic material or a conductor and installed on the movable member, and a signal generation unit that generates a detection signal from a reference signal by a filter using a coil, the signal generation unit being such that a frequency response of the filter changes according to a distance between the detected portion and the coil. According to the above aspect, since the frequency response of the filter with respect to the reference signal changes according to the distance between the detected portion and the coil, a detection signal at a level corresponding to the distance is generated. That is, a detection signal corresponding to the position of the movable member is generated. In the above configuration, since the level of the detection signal changes according to the frequency response of the filter, it is possible to greatly change the level of the detection signal with respect to the displacement of the movable member. Therefore, there is an advantage that a detection signal reflecting a minute displacement of the movable member with high accuracy can be generated.

[0075] The "movable member" includes not only performance operation elements such as keys or pedals directly operated by a user, but also structures such as hammers that are displaced in conjunction with an operation on the performance operation element. Further, the "distance between the detected portion and the coil" typically means the shortest distance between the detected portion and the coil. Therefore, even in a configuration where the detected portion rotates about a fixed central axis (that is, a configuration where the central axis does not move), the distance between the detected portion and the coil can change.

[0076] In a specific example (Aspect 2) of Aspect 1, the distance between the detected portion and the coil in the direction of the central axis of the coil changes according to the displacement of the movable member. According to the above aspect, compared with a configuration in which the detected portion and the coil relatively move in a plane perpendicular to the central axis of the coil (that is, a configuration in which the distance between the detected portion and the coil in the direction of the central axis of the coil does not change), it is possible to greatly change the level of the detection signal with respect to the displacement of the movable member.

[0077] In a specific example (Aspect 3) of Aspect 1 or Aspect 2, the movable member is a performance operator operated by a user, and the detected portion is a weight for adjusting the operating feeling of the performance operator by the user. According to the above aspect, since the weight for adjusting the operating feeling of the performance operator is also used as the detected portion, the configuration of the performance operating device is simplified as compared with a configuration in which the detected portion is provided separately from the weight.

[0078] In a specific example (Aspect 4) of any one of Aspect 1 to Aspect 3, the coil includes a first portion and a second portion, and the direction of the current flowing through the first portion and the direction of the current flowing through the second portion are opposite directions. According to the above aspect, since magnetic fields in opposite directions are generated in the first portion and the second portion, the diffusion of the magnetic field from the coil to the surroundings is reduced. Therefore, in a configuration in which a plurality of coils corresponding to different movable members are close to each other, detection signals that accurately reflect the displacement of each of the plurality of movable members can be generated.

[0079] In a specific example (Aspect 5) of Aspect 4, the detected portion faces both the first portion and the second portion. According to the above aspect, since the detected portion faces both the first portion and the second portion of the coil, the above-described effect of being able to generate a detection signal that accurately reflects the minute displacement of the movable member is particularly remarkable. Note that it is not necessary for the detected portion to face both the first portion and the second portion over the entire range in which the movable member is displaced. That is, it is sufficient that the detected portion faces both the first portion and the second portion when the movable member is in a specific position (for example, the position where the detected portion is closest to the coil).

[0080] In a specific example (Aspect 6) of any one of Aspect 1 to Aspect 5, the filter is a low-pass filter that suppresses components exceeding the cut-off frequency in the reference signal, and the cut-off frequency changes according to the distance between the detected portion and the coil.

[0081] In a specific example (Aspect 7) of any one of Aspect 1 to Aspect 5, the filter is a high-pass filter that suppresses components below the cut-off frequency in the reference signal, and the cut-off frequency changes according to the distance between the detected portion and the coil.

[0082] In a specific example (Aspect 8) of any one of Aspect 1 to Aspect 7, the filter is a band-stop filter that suppresses components in the stop band in the reference signal, and the stop band changes according to the distance between the detected portion and the coil.

[0083] The performance operation device according to a specific example (Aspect 9) of any one of Aspect 1 to Aspect 8 includes a sound control unit that generates an acoustic signal representing a sound corresponding to the level of the detection signal. According to the above aspect, since a detection signal that accurately reflects the minute displacement of the movable member is generated, an acoustic signal that reflects the minute displacement of the movable member can be generated.

[0084] In a specific example (Aspect 10) of any one of Aspect 1 to Aspect 9, the detected portion includes a coil.

Description of Reference Numerals

[0085] 100... Keyboard instrument (performance operation device), 10... Keyboard, 12... Keys, 20... Detection system, 21... Signal processing circuit, 22... Supply circuit, 23... Output circuit, 30... Information processing device, 31... Control device, 32... Storage device, 33... A / D converter, 34... Sound source circuit, 40... Sound playback device, 50... Tuning weight, 51... Rotating portion, 52... Load portion, 60... Signal generation portion, 61, 61A, 61B... Coils, 62, 62A, 62B... Capacitive elements, 63, 63A, 63B... Resistive elements, 91... String striking mechanism, 911... Hammer, 912... Transmission mechanism, 913... Support member, 92... Pedal mechanism, 921... Pedal, 922... Support member, 923... Elastic body.

Claims

1. A movable member that displaces according to a playing action, A detected part formed of a magnetic body or a conductor and installed on the movable member, A signal generation unit that generates a detection signal from a reference signal by a high-pass filter using a coil, and the frequency response of the high-pass filter changes according to the distance between the detected part and the coil Comprising, The high-pass filter is, An input terminal to which the reference signal is supplied, An output terminal that outputs the detection signal, A first capacitor element connected between the input terminal and the connection point, A second capacitor element connected between the connection point and the output terminal, The coil including a first coil connected to the connection point and a second coil connected to the output terminal, The magnetic field generated in the first coil and the magnetic field generated in the second coil are in opposite directions to each other A playing operation device.

2. A movable member that displaces according to a playing action, A detected part formed of a magnetic body or a conductor and installed on the movable member, A signal generation unit that generates a detection signal from a reference signal by a band-stop filter using a coil, and the frequency response of the band-stop filter changes according to the distance between the detected part and the coil Comprising, The band-stop filter is, An input terminal to which the reference signal is supplied, An output terminal that outputs the detection signal, A first resistor element connected between the input terminal and the output terminal, The coil connected to the output terminal, A second resistor element, Including a capacitor element connected between the coil and the second resistor element A playing operation device.

3. The coil includes a first part and a second part, The magnetic field generated in the first part and the magnetic field generated in the second part are in opposite directions to each other The playing operation device according to claim 2.

4. The movable member is a playing operation element operated by a user, The detected part is an adjustment weight for adjusting the operation feeling of the playing operation element by the user The playing operation device according to any one of claims 1 to 3.

5. Further comprising a support member for supporting the movable member, The adjustment weight is installed on the opposite side of the playing operation element with the support member interposed therebetween and displaces in conjunction with the movable member The playing operation device according to claim 4.

6. The support member includes a first surface and a second surface, The movable member is supported on the first surface, The signal generation unit is installed on the second surface The playing operation device according to claim 5.

7. A sound control unit that generates an acoustic signal representing a sound corresponding to the level of the detection signal The performance operation device according to any one of claims 1 to 3, comprising the same

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