Device for detecting key operation of keyboard device, method for detecting key operation of keyboard device, and keyboard device

Abstract

Provided is a key operation detection device (101) for a keyboard device, comprising: a key-side conductive part (20) provided to each of a plurality of keys (13); a circuit board (15) provided so as to face the plurality of keys (13) in the pressing direction of the plurality of keys (13); a plurality of sensor units (30), each of which has a coil, is provided on the circuit board (15) so as to correspond to each key (13), and outputs a signal corresponding to the distance from the key-side conductive unit (20) provided on the corresponding key (13); and a detection unit (50) that detects, on the basis of a signal output from the sensor unit (30), the position of the corresponding key (13) in the pressing direction and the displacement in the front-rear direction.

Description

[0001] This application is a divisional application of the Chinese national application No. 202180031662.3 (a detection device for key operations of a keyboard device, a method for detecting key operations, and a keyboard device) filed on April 28, 2021, and the content thereof is hereby incorporated by reference. Technical Field

[0002] The present invention relates to a detection device for key operations of a keyboard device, a method for detecting key operations, and a keyboard device having the detection device. Background Art

[0003] Conventionally, a keyboard device (Patent Document 1) is known in which a resonant circuit having a coil is provided between a key and a substrate as a non-contact sensor, and the position and speed of the key are detected based on a signal output from the resonant circuit of the substrate. Patent Document 1 can use a signal output unit (resonant circuit) having a coil to detect the position and speed of the key in the pressing direction. However, the key cannot be displaced in the front-rear direction.

[0004] On the other hand, Patent Documents 2 and 3 disclose keyboard devices having keys that can be displaced in the front-rear direction. Patent Documents 2 and 3 can detect the displacement of the key in the front-rear direction.

[0005] Patent Document 1: International Publication Patent Gazette WO2019 / 122867A1

[0006] Patent Document 2: US7723597

[0007] Patent Document 3: Japanese Utility Model Publication No. 49-004621 Summary of the Invention

[0008] However, in Patent Documents 2 and 3, the displacement of the key in the pressing direction and the displacement in the front-rear direction are detected at different positions. Therefore, it is necessary to provide signal output units separately for detecting the displacement in the pressing direction and the displacement in the front-rear direction.

[0009] An object of the present invention is to provide a detection device for key operations of a keyboard device that can detect not only the position of the key in the pressing direction but also the displacement of the key in the front-rear direction based on the output of the same signal output unit.

[0010] According to one aspect of the present invention, there is provided a detection device for key operations of a keyboard device, comprising: a conductive portion provided on each of a plurality of keys; a substrate provided to face the plurality of keys in the pressing and releasing direction of the plurality of keys; a plurality of signal output portions each having a coil, provided on the substrate corresponding to the plurality of keys respectively, and outputting a signal corresponding to a distance which is the distance between the signal output portion and the conductive portion provided on the corresponding key; and a detection portion which detects the position in the pressing and releasing direction of the corresponding key and the displacement in the front-back direction of the corresponding key based on the signals output from the plurality of signal output portions.

[0011] Effects of the Invention

[0012] According to one aspect of the present invention, it is possible to detect not only the position in the pressing and releasing direction of a key but also the displacement in the front-back direction of the key based on the output of the same signal output portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic side view of the keyboard device.

[0014] Figure 2 is a schematic diagram of a main part of the operation detection device.

[0015] Figure 3 is a schematic top view showing a structural example of the key-side conductive portion and the sensor portion.

[0016] Figure 4 is an enlarged view of the first conductive portion obtained by top view observation.

[0017] Figure 5 is an enlarged view of the first signal output portion obtained by top view observation.

[0018] Figure 6 is a circuit diagram of the first conductive portion.

[0019] Figure 7 is a circuit diagram of the first signal output portion.

[0020] Figure 8 is a schematic front view of one key and the corresponding sensor portion.

[0021] Figure 9 is a schematic top view showing a structural example of the key-side conductive portion and the sensor portion.

[0022] Figure 10 is a schematic top view showing a first structural example of the key-side conductive portion and the sensor portion of the second embodiment.

[0023] Figure 11 is a schematic top view showing a second structural example of the key-side conductive portion and the sensor portion.

[0024] Figure 12 is a schematic front view of a key and its corresponding sensor unit.

[0025] Figure 13 is a schematic front view of a key and its corresponding sensor unit.

[0026] Figure 14 is a schematic top view showing a structural example of a first modified example of the key-side conductive portion and the sensor unit.

[0027] Figure 15 is a schematic top view showing a structural example of a second modified example of the key-side conductive portion and the sensor unit. Detailed implementation mode

[0028] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0029] (First embodiment)

[0030] Figure 1 is a schematic side view of a keyboard device applying the key operation detection device according to the first embodiment of the present invention. Figure 1 is a view focusing on one key 13 among the plurality of keys 13 of the keyboard device 100. In Figure 1 , the front end side in the longitudinal direction of the key 13 is the front, and the key pressing surface (front surface) side is the upper side. The left-right direction is the direction indicated when observing from the front side of the key 13 where the performer is located. Therefore, the key arrangement direction is the same as the left-right direction. The longitudinal direction of the key 13 is also the front-rear direction. The keyboard device 100 is suitable for application to an electronic keyboard instrument and is also suitable for a device that outputs a sound signal without generating sound.

[0031] A leaf spring 19 is provided on the frame 11. A fulcrum 12 is fixed to the upper end of the leaf spring 19. The leaf spring 19 can flex in the front-rear direction (Y direction). The leaf spring 19 does not flex and stands straight in the non-operating state where the key 13 is not operated. Along with the flexing of the leaf spring 19, the fulcrum 12 generates a displacement in the front-rear direction. As the fulcrum 12 generates a displacement in the front-rear direction, the entire key 13 also generates a displacement in the front-rear direction. The front end portion of the key 13 can rotate in the up-down direction (Z direction) with the fulcrum 12 as the center. Thus, by operation, a displacement in the front-rear direction and a rotation with the fulcrum 12 as the center can be generated in parallel on the key 13.

[0032] The key 13 has a protruding portion 16 and a protruding portion 17. A key-side conductive portion 20 described later is provided at the lower end of the protruding portion 16. A circuit board 15 is provided on the frame 11. The circuit board 15 is disposed opposite to each key 13 in the pressing direction of the plurality of keys 13. A sensor unit 30 described later is disposed corresponding to the key-side conductive portion 20 on the circuit board 15.

[0033] A coil spring 14 is installed between the key 13 and the frame 11 in a compressed state. The coil spring 14 always presses the key 13 upward. A lower stopper 18 is provided on the frame 11 opposite to the protruding portion 17. The key 13 in the non-operating state touches an upper stopper (not shown), and thus is restricted to Figure 1 the shown initial position (non-pressing position). If the performer presses the key 13, the coil spring 14 is compressed, and the protruding portion 17 touches the lower stopper 18. The lower limit position of the key stroke of the protruding portion 17 is restricted by the lower stopper 18. The lower stopper 18 can elastically deform within a specified range and elastically deforms when pressed by the protruding portion 17. The position where the lower stopper 18 elastically deforms within a specified range becomes the lowest limit position of the key stroke of the protruding portion 17. It is also possible to separately provide the lower stopper 18 and a stopper for defining the lowest limit position. If the performer releases the key 13 from the key-pressing end state where the lower stopper 18 is pressed by the protruding portion 17, the key 13 returns to the initial position due to the force of the coil spring 14.

[0034] During the key stroke of the key 13, the key-side conductive portion 20 approaches the sensor portion 30, and during the key-release stroke of the key 13, the key-side conductive portion 20 moves away from the sensor portion 30. Here, even when the protruding portion 17 reaches the lowest limit position, the key-side conductive portion 20 does not contact the sensor portion 30. Therefore, the key-side conductive portion 20 and the sensor portion 30 are always in a non-contact relationship. As will be described in detail later, the key-side conductive portion 20 is composed of a pair of conductive portions 21 and 22 ( Figure 3 ). The sensor portion 30 has, for example, two (a pair of) signal output portions 31 and 32 as a plurality of signal output portions that output signals corresponding to the following distance ( Figure 3 ), and this distance is the distance between the signal output portions 31 and 32 and the key-side conductive portion 20 of the corresponding key 13.

[0035] Among the plurality of keys 13, there are a plurality of white keys and a plurality of black keys. The plurality of keys 13 are arranged in the left-right direction (key arrangement direction) when viewed from the performer. The structures of each key 13 and its corresponding key-side conductive portion 20 and sensor portion 30 are common. The front end portion of the key 13 swings in the pressing and releasing direction, that is, the pitching direction, through the pressing operation and the releasing operation. In addition, if the performer applies a force to the key 13 in the forward and backward directions during the process of pressing the key 13 or in the pressed state, the leaf spring 19 deforms and the key 13 and the fulcrum 12 are displaced in the forward and backward directions together.

[0036] In the past, by further key operations in the key release stage, the after touch was detected and used for sound control to broaden the sound expression. Typically, as the after touch, the increase or decrease of the force in the pressing and releasing direction is detected in the key release stage. However, not only that, if the player can intentionally displace the key in the front-back direction in the key release stage to generate the after touch, the expressiveness will be improved. As will be described later in detail, in the present embodiment, through the combination of the key-side conductive portion 20 and the sensor portion 30, it is possible to non-contact detect not only the stroke position of the key 13 but also the displacement in the front-back direction. Moreover, they can be detected not only in the key release stage but also during the key press and key release.

[0037] Figure 2 It is a schematic diagram of the main part of the operation detection device 101. The operation detection device 101 includes, in addition to the key-side conductive portion 20 and the sensor portion 30, an addition portion 51, a subtraction portion 52, and a control portion 50. The detection portion of the present invention mainly includes the addition portion 51, the subtraction portion 52, and the control portion 50. Although the control portion 50 is not shown, it includes a CPU, a RAM, a ROM, a timer, etc. The sound generation portion 53 includes a sound source circuit and an effect circuit. The control portion 50 controls the sound generation realized by the sound generation portion 53 based on the detection results of the operations of the respective keys 13 detected by the operation detection device 101. For example, the control portion 50 controls the sound generation and muting based on the detection results in the pitch direction, and controls the effects of the generated sound based on the detection results related to the displacement in the front-back direction. The details of the effect imparting will be described later.

[0038] Figure 3 It is a schematic top view showing a structural example of the key-side conductive portion 20 and the sensor portion 30. In Figure 3 the key-side conductive portion 20 is shown as a projection view obtained by top view (planar view). Figure 3 To the left of Figure 3 is the rear of a certain key 13 of the fulcrum 12. In addition, in

[0039] The sensor unit 30 is provided corresponding to each key 13 and includes a pair of signal output units (the first signal output unit 31 and the second signal output unit 32). The first signal output unit 31 and the second signal output unit 32 are arranged in the front-rear direction. The first signal output unit 31 is a circuit having a coil in which two spiral portions are connected. The second signal output unit 32 is also a circuit having a coil in which two spiral portions (winding portions 35, 36) are connected. The structures of the first conductive portion 21 and the second conductive portion 22 are common. The structures of the first signal output unit 31 and the second signal output unit 32 are common. Using Figures 4 - 7 , the detailed structures of the first conductive portion 21 and the first signal output unit 31 will be described representatively.

[0040] Figure 4 is an enlarged view of the first conductive portion 21 obtained by a top view. The first conductive portion 21 has a coil C21 having an overall figure-eight shape. The coil C21 is arranged in a planar shape at the lower end of the protruding portion 16. The coil C21 is continuous from the via hole 27 to the via hole 28 via the capacitor 29. And, the via hole 27 and the via hole 28 are directly connected on the back surface of the substrate. The winding portion 23 and the winding portion 24 are adjacent to each other. Let the centroid positions of the winding portions 23 and 24 be the centroids G1 and G2, respectively. In addition, the centroids G1 and G2 are defined as the centroid positions of the figures having an approximately circular contour shape of the winding portions 23 and 24. Alternatively, the centroids G1 and G2 can also be defined as the mass-based centroid positions of the winding portions 23 and 24, respectively. The straight line L1 passing through the centroids G1 and G2 is approximately parallel to the key arrangement direction. The straight line L2 ( Figure 3 ) passing through the centroids G1 and G2 of the winding portions 25 and 26 of the second conductive portion 22 is also approximately parallel to the key arrangement direction. Therefore, the first conductive portion 21 and the second conductive portion 22 are arranged such that the straight lines L1 and L2 are approximately parallel.

[0041] Figure 5 is an enlarged view of the first signal output unit 31 obtained by a top view. The first signal output unit 31 has a coil C31 having an overall figure-eight shape. The coil C31 is arranged in a planar shape on the circuit board 15. The coil C31 is continuous from the via hole 37 to the via hole 38 via the capacitors 39 and 40. And, the via hole 37 and the via hole 38 are directly connected on the back surface of the substrate. A resistor 41 is connected to the capacitor 39 and a resistor 42 is connected to the capacitor 40. It is not necessary to provide the resistors 41 and 42. The winding portion 33 and the winding portion 34 are adjacent to each other. Let the centroid positions of the winding portions 33 and 34 be the centroids G3 and G4, respectively. In addition, the definition of the centroids G3 and G4 is the same as that of the centroids G1 and G2. The straight line L3 passing through the centroids G3 and G4 is approximately parallel to the key arrangement direction. The straight line L4 ( Figure 3) is also approximately parallel to the key arrangement direction. Therefore, the first signal output unit 31 and the second signal output unit 32 are arranged such that the straight lines L3 and L4 are approximately parallel. Additionally, as Figure 3 shown, the interval between the straight lines L3 and L4 is wider than the interval between the straight lines L1 and L2.

[0042] As Figure 4 shown, the swirling directions of the winding portions 23 and 24 with respect to their centers are the same as each other. That is, when the through-hole 28 close to the center of gravity G1 is regarded as the starting point, the swirling direction of the winding portion 23 is the right-rotating (clockwise) direction. When the through-hole 27 close to the center of gravity G2 is regarded as the starting point, the swirling direction of the winding portion 24 is also the right-rotating direction. According to the relationship described above, when a current flows in a certain direction through the coil C21, the directions of the magnetic fluxes in the winding portion 23 and the winding portion 24 are opposite. Similarly, as Figure 5 shown, the swirling directions of the winding portions 33 and 34 with respect to their centers are the same as each other. When a current flows in a certain direction through the coil C31, the directions of the magnetic fluxes in the winding portion 33 and the winding portion 34 are opposite.

[0043] Figure 6 is the circuit diagram of the first conductive portion 21. Figure 7 is the circuit diagram of the first signal output unit 31. The first conductive portion 21 is configured as a resonant circuit on the passive side. The first conductive portion 21 is a closed circuit. The first signal output unit 31 is configured as a resonant circuit on the active side. The above-mentioned resonant circuit is basically the same as the structure disclosed in Patent Document 1 (WO2019 / 122867A1).

[0044] In the first signal output unit 31, the input-side terminal 44 is connected to a drive circuit (not shown). The detection signal is taken out from the output-side terminal 43. As Figure 2 shown, the detection signal from the second signal output unit 32 is input to the + terminal of the addition unit 51 and the + terminal of the subtraction unit 52. The detection signal from the first signal output unit 31 is input to the other + terminal of the addition unit 51 and the - terminal of the subtraction unit 52. In addition, in order to correct the phase deviation between the detection signal from the first signal output unit 31 and the detection signal from the second signal output unit 32, their respective outputs may also be input to the addition unit 51 and the subtraction unit 52 via a smoothing circuit (not shown). The addition unit 51 outputs the sum of the detection signals from the first signal output unit 31 and the second signal output unit 32 to the control unit 50. The subtraction unit 52 outputs the difference between the detection signal from the first signal output unit 31 and the detection signal from the second signal output unit 32 to the control unit 50. The above-mentioned detection signals are continuous quantities.

[0045] The outputs of the signal output units 31 and 32 are, for example, voltage values. When the signal output units 31 and 32 are driven at a specified resonance frequency, if the first conductive part 21 approaches the first signal output unit 31, then in the first conductive part 21, a current flows in a direction that cancels out the magnetic flux generated in the first signal output unit 31. As a result, the magnetic flux of the first signal output unit 31 changes and the voltage changes. Therefore, the detection signal can be taken out as a voltage value. Corresponding to the first conductive part 21 approaching the first signal output unit 31, the output of the first signal output unit 31 becomes smaller. Similarly, if the second conductive part 22 approaches the second signal output unit 32, then correspondingly the output of the second signal output unit 32 becomes smaller. That is, the outputs (voltages) of the signal output units 31 and 32 change corresponding to the distances from the corresponding conductive parts 21 and 22, and the shorter the distance, the smaller the output (voltage). In addition, as the outputs of the signal output units 31 and 32, changes in resonance signals and current values can also be used.

[0046] In particular, as described above, both the coil C21 and the coil C31 are in the shape of an "8". Therefore, the relationship between the first signal output unit 31 and the first conductive part 21 is as follows. First, in a state where upward magnetic flux has occurred from the winding part 33 of the first signal output unit 31 and downward magnetic flux has occurred from the winding part 34, it is assumed that the first conductive part 21 approaches the first signal output unit 31. Then, a current flows in the winding part 23 of the first conductive part 21 in a direction that cancels out the upward magnetic flux from the winding part 33. As a result, upward magnetic flux occurs in the winding part 24 of the first conductive part 21, and therefore, the downward magnetic flux of the winding part 34 of the first signal output unit 31 weakens. Therefore, compared with a structure in which the winding directions of the winding part 33 and the winding part 34 are opposite, the change amplitude of the output of the first signal output unit 31 is large. As a result, the sensitivity of the sensor becomes high.

[0047] In addition, from the viewpoint of crosstalk suppression, the resonance frequencies can also be made different between the first signal output unit 31 and the second signal output unit 32. Further, as disclosed in Patent Document 1 (WO2019 / 122867A1), the resonance frequencies can also be made different between multiple sensor units 30. In particular, the resonance frequencies can also be made different between the sensor units 30 corresponding to adjacent keys 13. Further, as disclosed in Patent Document 1 (WO2019 / 122867A1) and Japanese Patent No. 4375302, time-division processing can also be performed using a multiplexer and a demultiplexer when driving each sensor unit 30. For example, multiple sensor units 30 are grouped according to key domains so that physically adjacent sensor units 30 are not driven simultaneously. For example, in each group, starting from the sensor unit 30 in the low domain, they can be driven one by one simultaneously in each group.

[0048] Figure 8 is a schematic front view of a key 13 and a corresponding sensor unit 30. The stroke position (position in the pressing direction) and the displacement in the front-rear direction of the key 13 are detected in the following manner.

[0049] First, when the key-side conductive part 20 approaches the sensor unit 30 by a key operation, as Figure 2 shown, the detection signals of the signal output parts 31, 32 are input to the addition part 51 and the subtraction part 52. The control part 50 detects the stroke position of the key 13 based on the sum of the detection signals of the signal output parts 31, 32 input from the addition part 51. At this time, for example, the smaller the sum of the signals, the deeper the stroke position is detected.

[0050] In parallel with this, the control part 50 detects the magnitude of the displacement of the key 13 in the front-rear direction based on the difference between the detection signals of the signal output parts 31, 32 input from the subtraction part 52. At this time, the larger the difference between the signals, the larger the displacement in the front-rear direction is detected. As Figure 8 shown, if the key 13 is pressed and a force is applied in the forward direction, the key 13 generates a displacement in the forward direction. In this case, the overlapping area of the first conductive part 21 and the first signal output part 31 is larger than the overlapping area of the second conductive part 22 and the second signal output part 32. Therefore, the first signal output part 31 outputs a detection signal smaller than that of the second signal output part 32, and thus the difference between the detection signals becomes larger.

[0051] As described above, as Figure 3 shown, the interval between the straight lines L3, L4 is larger than the interval between the straight lines L1, L2. That is, the first signal output part 31 is offset and arranged forward with respect to the first conductive part 21, and the second signal output part 32 is offset and arranged backward (in the opposite direction of the first signal output part 31) with respect to the second conductive part 22. For example, consider the case where, as Figure 8 shown, the key 13 is subjected to a force in the forward direction and the key 13 generates a displacement in the forward horizontal direction. In this case, in the projection obtained by a top view, the overlapping area of the first conductive part 21 and the first signal output part 31 is larger than the overlapping area of the second conductive part 22 and the second signal output part 32. Therefore, the magnetic flux that the first conductive part 21 acts on the first signal output part 31 is stronger than the magnetic flux that the second conductive part 22 acts on the second signal output part 32. Then, the first signal output part 31 outputs a detection signal smaller than that of the second signal output part 32, and thereby the difference between the detection signals becomes larger. As a result, the control part 50 can detect the situation where the key 13 has generated a displacement in the forward direction and the magnitude of the displacement of the key 13 in the forward direction. When the key 13 generates a displacement in the backward direction, the difference between the above detection signals is reversed.

[0052] With the offset configuration described above, the difference between the signal output units 31 and 32 when the key 13 is displaced in the front-rear direction becomes larger, so the sensitivity of the detection related to the front-rear direction becomes higher. The control unit 50 controls the sound effect based on the detected displacement in the front-rear direction.

[0053] In addition, the direction of the offset can also be opposite to the illustrated direction. Further, it is not necessary to have an offset configuration, and the intervals between the straight lines L1 and L2 and between the straight lines L3 and L4 can be the same, and the straight lines L1 and L2 and the straight lines L3 and L4 can overlap respectively. In this case, from the viewpoint of crosstalk suppression, it is preferable to arrange the key-side conductive part 20 and the sensor part 30 such that the center of gravity G1 coincides with the center of gravity G3 and the center of gravity G2 coincides with the center of gravity G4.

[0054] The control unit 50 also detects the stroke position of the key 13 at any time during the key press and during the key release. When the stroke position of the key 13 is deeper than the first specified position, the control unit 50 generates a note-on event and causes the sound generation unit 53 to start sounding. After the sounding starts, the control unit 50 performs post-control to impart effects such as vibrato based on the magnitude of the detected displacement in the front-rear direction. For example, the greater the displacement in the front-rear direction, the greater the degree of the imparted effect by the control unit 50 and the shorter the period. In addition, the detection result can be used for the control of effect imparting not only at the end stage of the key press of the key 13 but also during the key press and during the key release.

[0055] In addition, when the stroke position of the key 13 is shallower than the second specified position (shallower than the first specified position) during the sounding process, the control unit 50 causes the sound generation unit 53 to start muting. Further, the control unit 50 detects the key press speed based on the time required for the key 13 to reach the first specified position from the third specified position (shallower than the first specified position) and uses it for sound control such as volume. Similarly, the key release speed can also be detected during the key release operation and used for sound control. In addition, the effect parameters to be controlled are not limited.

[0056] The above-mentioned Figure 3 The illustrated configuration can be applied to either white keys or black keys, but it is difficult to implement if the key width is narrow. Figure 3 The illustrated configuration is suitable for white keys. In Figure 9 a configuration suitable for black keys with a narrow key width is described.

[0057] Figure 9 is a schematic top view showing a structural example of the key-side conductive part 20 and the sensor part 30. In Figure 9 the key-side conductive part 20 is shown as a projection view obtained by top view observation. In addition, in Figure 9 the illustration of the capacitor and the resistor is omitted. The structures of the first conductive part 21, the second conductive part 22, the first signal output unit 31, and the second signal output unit 32 are the same as those inFigure 3 The structure described is the same.

[0058] As Figure 9 shown, the conductive parts 21 and 22 are arranged in a straight line in the key length direction (front - rear direction). The signal output parts 31 and 32 are also arranged in the key length direction. In the front - rear direction (Y direction), the conductive parts 22 and 32 are closer to the fulcrum 12 than the conductive parts 21 and 31. On the other hand, the interval L6 between the first signal output part 31 and the second signal output part 32 is larger than the interval L5 between the first conductive part 21 and the second conductive part 22 in the front - rear direction. That is, the first signal output part 31 is offset forward relative to the first conductive part 21, and the second signal output part 32 is offset backward relative to the second conductive part 22. In addition, the intervals L5 and L6 can also be defined as the intervals between the centers of gravity of the respective conductive parts and the intervals between the centers of gravity of the respective signal output parts. In addition, in the white keys, the configuration shown in Figure 9 can also be adopted.

[0059] According to the present embodiment, a pair of conductive parts, i.e., key - side conductive parts 20, are provided for each of the plurality of keys 13. A sensor part 30 (a pair of signal output parts 31 and 32) is provided on the circuit board 15 corresponding to each key 13. The sensor part 30 outputs a signal corresponding to the distance from the corresponding key 13 to the key - side conductive part 20. The control part 50 obtains the signal output from the sensor part 30, and based on the obtained signal, detects the position in the pressing - down direction of the corresponding key 13 and the displacement in the front - rear direction of the corresponding key 13. For example, the control part 50 detects the stroke of the key 13 based on the sum of the signals respectively output from the signal output parts 31 and 32, and detects the displacement in the front - rear direction of the key 13 based on the difference between the respectively output signals. Thus, based on the output of the same (common) signal output parts 31 and 32, it is possible to detect not only the position in the pressing - down direction of the key 13 but also the displacement in the front - rear direction.

[0060] In particular, the displacement of the key 13 in the front - rear direction can be detected with high precision through the Figure 3 , Figure 9 shown offset configuration.

[0061] In addition, in each of the key - side conductive part 20 and the sensor part 30, the spiral directions of two adjacent spiral - shaped parts with respect to the center are the same, so crosstalk can be suppressed.

[0062] In addition, for the detection of the stroke position, it is not necessary to use the sum of the signals, and the stroke position can also be detected based on either one of the pair of signal output parts 31 and 32.

[0063] (Second Embodiment)

[0064] In the first embodiment, based on the signal output from the sensor unit 30, the position in the pressing direction and the displacement in the front-rear direction of the key 13 are detected. In the second embodiment of the present invention, on top of the above, the displacement in the yaw direction or the roll direction of the key 13 can also be detected.

[0065] First, the key 13 mainly generates displacement in the pitch direction, and strictly speaking, also generates displacement in the yaw direction and the roll direction. That is, when the key 13 is subjected to a force in the left-right direction, displacement may also occur in the yaw direction. Also, when the key 13 is subjected to a force in the left-right direction, or when the end position in the width direction is pressed, the key 13 can generate displacement in the direction of rotation (roll direction) about an axis along the length direction. In addition, although the key 13 mainly generates displacement in the pitch direction, the structure of the key 13 can be designed to generate displacement in the roll direction and the yaw direction as disclosed in, for example, Japanese Patent No. 4375302.

[0066] Figure 10 、 Figure 11 FIG. 10 is a schematic plan view showing first and second structural examples of the key-side conductive portion 20 and the sensor unit 30 according to the second embodiment. Figure 12 、 Figure 13 FIG. 11 is a schematic front view of one key 13 and the corresponding sensor unit 30 according to the first structural example.

[0067] In Figures 10 - 13 , the conductive portions A1 and A2 are configured in the same manner as the conductive portions 21 and 22 shown in Figure 9 . The conductive portions A3 and A4 are also configured in the same manner as the conductive portions 21 and 22 shown in Figure 9 . The signal output portions B1 and B2 are configured in the same manner as the signal output portions 31 and 32 shown in Figure 9 . The signal output portions B3 and B4 are configured in the same manner as the signal output portions 31 and 32 shown in Figure 9 . In Figure 10 , Figure 11 , the conductive portions A1 to A4 are shown as projection views obtained by top-down observation (planar observation). In either the first or the second structural example, in the front-rear direction (Y direction), the conductive portion A2 and the signal output portion B2 are closer to the fulcrum 12 than the conductive portion A1 and the signal output portion B1.

[0068] In the first and second structural examples ( Figure 10 , Figure 11 ), the conductive portions A1 to A4 are offset in both the front-rear direction and the key arrangement direction with respect to the signal output portions B1 to B4. In the first structural example ( Figure 10) In [the structure], in the key arrangement direction, the intervals between the signal output parts B1 and B3 are larger than the intervals between the conductive parts A1 and A3, and the intervals between the signal output parts B2 and B4 are larger than the intervals between the conductive parts A2 and A4. In the front-rear direction, the intervals between the signal output parts B1 and B2 are larger than the intervals between the conductive parts A1 and A2, and the intervals between the signal output parts B3 and B4 are larger than the intervals between the conductive parts A3 and A4.

[0069] In the second structural example ( Figure 11 ) the signal output parts B1 to B4 are arranged in a straight line in the front-rear direction. In the key arrangement direction, the conductive parts A1 and A3 are offset from each other to opposite sides with the signal output parts B1 and B3 therebetween, and the conductive parts A2 and A4 are offset from each other to opposite sides with the signal output parts B2 and B4 therebetween. In the front-rear direction, the intervals between the signal output parts B1 and B2 are larger than the intervals between the conductive parts A1 and A2, and the intervals between the signal output parts B3 and B4 are larger than the intervals between the conductive parts A3 and A4.

[0070] Taking the first structural example ( Figure 10 ) as an example, a method for detecting the stroke position, displacement in the front-rear direction, and yaw (displacement in the deflection direction or roll direction) of the key 13 will be described.

[0071] First, for detecting the stroke position and displacement in the front-rear direction of the key 13, combinations of "the conductive part A1 and the signal output part B1" and "the conductive part A2 and the signal output part B2" are used. That is, the control unit 50 detects the stroke position of the key 13 based on the sum of the detection signals of the signal output parts B1 and B2. In addition, the control unit 50 detects the magnitude of the displacement in the front-rear direction of the key 13 based on the difference between the detection signals of the signal output parts B1 and B2. Furthermore, for detecting the stroke position and displacement in the front-rear direction of the key 13, combinations of "the conductive part A3 and the signal output part B3" and "the conductive part A4 and the signal output part B4" can also be used.

[0072] Next, for detecting yaw, combinations of "the conductive part A1 and the signal output part B1" and "the conductive part A3 and the signal output part B3" are used. That is, the control unit 50 detects the magnitude of the yaw of the key 13 based on the difference between the detection signals of the signal output parts B1 and B3 input from the subtraction unit 52. At this time, the greater the signal difference, the greater the yaw is detected as a value. If the signal output parts B1 and B2 are set as a pair of signal output parts for detecting the stroke position and displacement in the front-rear direction, then the signal output parts B1 and B3 correspond to another pair of signal output parts for detecting yaw.

[0073] As Figure 12As shown, if the right part of the key surface of key 13 is pressed, key 13 rolls to the right. In this case, the distance between the conductive part A1 and the signal output part B1 is shorter than the distance between the conductive part A3 and the signal output part B3. Therefore, the signal output part B1 outputs a detection signal smaller than that of the signal output part B3, so the difference in the detection signals becomes larger. As a result, the control unit 50 can detect the rolling direction and the magnitude of the rolling displacement of key 13.

[0074] In addition, as described above, the interval between the signal output parts B1 and B3 is wider than the interval between the conductive parts A1 and A3. As Figure 13 shown, if a force is applied to key 13 to the right, key 13 generates a displacement to the right side in the horizontal direction. In this case, in the projection obtained by top-down observation, the overlapping area between the conductive part A1 and the signal output part B1 is larger than the overlapping area between the conductive part A3 and the signal output part B3. Therefore, the magnetic flux of the conductive part A1 acting on the signal output part B1 is stronger than the magnetic flux of the conductive part A3 acting on the signal output part B3. Then, the signal output part B1 outputs a detection signal smaller than that of the signal output part B2, so the difference in the detection signals becomes larger. As a result, the control unit 50 can detect the magnitude of the displacement in the deflection direction of key 13. Through the offset configuration described above, the difference between the signal output parts B1 and B3 when key 13 is displaced in the horizontal direction becomes larger, so the sensitivity of the detection related to the deflection direction becomes higher.

[0075] In addition, the displacements in the deflection direction and the rolling direction (so-called yaw) are generated complexly, and it is difficult for the performer to be aware of both and perform. In the detection, it doesn't make much sense to distinguish between the two. Therefore, the control unit 50 can also capture both complexly and detect them as yaw, which is beneficial for effect control. However, it is possible to detect the yaw not only at the end of the key press but also during the key press and during the key release.

[0076] In addition, in the case of detecting the yaw, it is also possible to determine whether the yaw is mainly caused by the rolling displacement or the deflection displacement based on the difference between the difference between the signal output parts B1 and B3 and the difference between the signal output parts B2 and B4. For example, in the key arrangement direction, if the displacement is generated more significantly at the front end of the key than at the rear end of the key, and thus the difference value is large, it can be determined that the yaw is mainly caused by the deflection displacement. In addition, for the detection of the yaw, the combination of "the conductive part A2 and the signal output part B2" and "the conductive part A4 and the signal output part B4" can also be used.

[0077] In adopting the second structural example ( Figure 11) In the case of, it is possible to detect the stroke position, displacement in the front - rear direction, and yaw of the key 13. For example, for the detection of the stroke position and displacement in the front - rear direction of the key 13, a combination of "conductive part A1 and signal output part B1" and "conductive part A2 and signal output part B2" is used. Alternatively, a combination of "conductive part A3 and signal output part B3" and "conductive part A4 and signal output part B4" can also be used. In addition, for the detection of yaw, a combination of "conductive part A1 and signal output part B1" and "conductive part A3 and signal output part B3" is used. Alternatively, a combination of "conductive part A2 and signal output part B2" and "conductive part A4 and signal output part B4" can also be used.

[0078] According to the present embodiment, regarding the detection of not only the position in the pressing - releasing direction of the key 13 but also the displacement in the front - rear direction based on the output of the same (common) signal output part, the same effect as that of the first embodiment can be achieved. Moreover, based on the output of the same (common) signal output part, it is also possible to detect the displacement in the deflection direction or roll direction of the key during the key - pressing process.

[0079] In addition, in the first structural example ( Figure 10 ), the second structural example ( Figure 11 ), for any of them, two spiral - shaped parts of each of the conductive parts A1 - A4 and signal output parts B1 - B4 are arranged in the front - rear direction. However, two spiral - shaped parts of each of the conductive parts A1 - A4 and signal output parts B1 - B4 can also be arranged in the key - arrangement direction.

[0080] In addition, in the present embodiment, for the detection of the stroke position, displacement in the front - rear direction, and yaw, the sensor parts used can be made common, so the structure is simple and there is no need to provide an optical sensor. However, an optical or contact - type position sensor and speed sensor can also be provided separately for detecting the stroke position and key - pressing speed. In addition, it is not necessary to detect the stroke position by a pair of signal output parts.

[0081] Next, in Figure 14 , Figure 15 , modified examples of the above - mentioned respective embodiments will be described. Figure 14 is a schematic top - view showing a structural example of a first modified example of the key - side conductive part 20 and the sensor part 30. In the example shown in Figure 14 , relative to Figure 3In the example shown, the winding directions of the winding portions 23 and 24 of the first conductive portion 21 are opposite. Therefore, the swirl directions with the center as the reference point of the winding portions adjacent to each other in the front-rear direction, that is, the winding portion 23 of the first conductive portion 21 and the winding portion 25 of the second conductive portion 22, are opposite to each other. Similarly, the swirl directions with the center as the reference point of the winding portions 24 and 26 adjacent to each other in the front-rear direction are also opposite to each other.

[0082] In addition, similarly, in Figure 14 the example shown, relative to Figure 3 the example shown, the winding directions of the winding portions adjacent to each other in the front-rear direction, that is, the winding portions 33 and 34 of the first signal output portion 31, are opposite. Therefore, the swirl directions with the center as the reference point of the winding portion 33 and the winding portion 35 adjacent to each other in the front-rear direction are opposite to each other. Similarly, the swirl directions with the center as the reference point of the winding portions 34 and 36 adjacent to each other in the front-rear direction are opposite to each other. As described above, in each of the key-side conductive portion 20 and the sensor portion 30, the swirl directions with the center as the reference point between the winding portions adjacent to each other in the front-rear direction are opposite to each other. With this structure, not only in the key arrangement direction, but also between the winding portions adjacent to each other in the key length direction, the directions of the magnetic fluxes generated are opposite, so it is more beneficial to suppress crosstalk.

[0083] In addition, in each of the above-described embodiments, the conductive portions 21 and 22 and the signal output portions 31 and 32 do not necessarily have to be approximately parallel to the key arrangement direction or the key length direction. The conductive portion and the corresponding signal output portion may be inclined in the same direction, but do not necessarily have to be inclined in the same direction.

[0084] Figure 15 is a schematic top view showing a structural example of a second modified example of the key-side conductive portion 20 and the sensor portion 30. In each of the above-described embodiments, as Figure 15 shown, the conductive portions 21 and 22 (or conductive portions A1 to A4) and the signal output portions 31 and 32 (or signal output portions B1 to B4) may each be formed by a coil formed of a single swirl instead of two swirls. In addition, either the group of the conductive portion 21 and the signal output portion 31 or the group of the conductive portion 22 and the signal output portion 32 may be formed as a group of coils formed of a single swirl.

[0085] In addition, the key-side conductive portion is preferably a reactive component, not limited to an induction coil, and a conductive member may also be used for the key-side conductive portion. For example, regarding the key-side conductive portion, as shown for the key-side conductive portion 20-2, conductive metal plates 54 and 55 may be provided in place of the conductive portions 21 and 22. The metal plates 54 and 55 are made of iron or the like. The metal plates 54 and 55 are plate members approximately parallel to the key surface. If the distance between the metal plates 54 and 55 from the signal output portions 31 and 32 changes, the capacitance of the signal output portions 31 and 32 changes, and thus a signal corresponding to the distance can be extracted.

[0086] Alternatively, as shown for the key-side conductive portion 20-3, one conductive metal plate 56 having the same conductivity as the metal plates 54 and 55 may be provided in place of the conductive portions 21 and 22. In addition, when the key-side conductive portion 20-2 or the key-side conductive portion 20-3 is adopted, the coil shape of the signal output portions 31 and 32 may be two vortices or a single vortex.

[0087] In addition, it is also possible to detect the parallel movement of the key in the horizontal direction or the up-and-down direction based on the output of the same (common) signal output portion. For example, in a keyboard configured to enable the entire key to be displaced parallel to the key arrangement direction, it may also be configured to be able to detect the parallel movement of the key in the key arrangement direction. Or, in a keyboard configured to enable the entire key to be displaced parallel in the up-and-down direction, it may also be configured to be able to detect the parallel movement of the key in the up-and-down direction. At this time, based on the detection objects illustrated in the above embodiments, or in place of the illustrated detection objects, it may also be possible to detect the parallel movement of the key in the horizontal direction or the up-and-down direction.

[0088] In addition, in each of the examples including the above-described modification examples, the signal output portion that outputs a signal corresponding to the distance from the corresponding key-side conductive portion 20 may also be provided such that two or more signal output portions correspond to a plurality of respective keys 13, not limited to two. For example, two or more pairs of signal output portions may be provided, and displacement may be detected using the signals from each pair. Or, three signal output portions may be arranged, and the middle signal output portion may be dedicated to detecting the stroke position.

[0089] In addition, the key operation detection device of the present invention does not necessarily have to be able to detect the operations of all the keys 13 of the keyboard device 100, and only a part of the keys 13 may be used as the detection object.

[0090] In addition, the contour shapes of the spiral-shaped portions of the coils C21 and C31 that constitute the conductive portions 21 and 22 and the signal output portions 31 and 32 are not limited to circular shapes, and may also be oval or rectangular. Further, the coils C21 and C31 are planar, and if the arrangement space permits, they do not need to be limited to planar shapes.

[0091] In addition, the present invention is not limited to the keyboard device 100, and can also be applied to pedals, keyboards for personal computers, and the like.

[0092] In addition, in the present embodiment, the addition of the content "approximate" does not mean complete exclusion. For example, "approximately parallel" and "approximately circular" respectively include the meanings of parallel and circular.

[0093] As described above, the present invention has been described in detail based on its preferred embodiments. The present invention is not limited to the above specific embodiments, and various modes within the scope not departing from the gist of the present invention are also included in the present invention. It is also possible to appropriately combine a part of the above embodiments.

[0094] This application is based on a Japanese application (Japanese Patent Application No. 2020-085055) filed on May 14, 2020, the content of which is incorporated herein by reference.

[0095] Description of Reference Numerals

[0096] 13 Keys

[0097] 15 Circuit Board

[0098] 20 Key-Side Conductive Portion

[0099] 21, 22 Conductive Portions

[0100] 31, 32 Signal Output Portions

[0101] 30 Sensor Portion

[0102] 50 Control Portion

[0103] 101 Operation Detection Device

Claims

1. A detecting device for key operations of a keyboard device, comprising: A conductive part provided on each of a plurality of keys; A substrate, which is arranged to be opposite to the plurality of keys in the pressing and releasing direction of the plurality of keys; A plurality of signal output units, each having a coil, are arranged on the substrate corresponding to the plurality of keys respectively, and output signals corresponding to the following distance, which is the distance between the signal output unit and the conductive part arranged on the corresponding key; And A detection unit, which detects the displacement of the corresponding key in the front-back direction based on the signals output from the plurality of signal output units.

2. The detecting device for key operations of a keyboard device according to claim 1, wherein At least one pair of the signal output units is arranged corresponding to one of the plurality of keys, The detection unit detects the displacement of the corresponding key in the front-back direction based on the difference between the signals output from each of the pair of signal output units.

3. The detecting device for key operations of a keyboard device according to claim 2, wherein The pair of signal output units are arranged in the front-back direction of the key.

4. The detecting device for key operations of a keyboard device according to claim 3, wherein The first signal output unit of the pair of signal output units is arranged to be offset in the first direction in the front-back direction with respect to the conductive part, The second signal output unit of the pair of signal output units is arranged to be offset in the second direction with respect to the conductive part, and the second direction is the direction opposite to the first direction of the first signal output unit in the front-back direction.

5. The detecting device for key operations of a keyboard device according to claim 2, wherein The detection unit detects the position of the corresponding key in the pressing and releasing direction based on the sum of the signals output from each of the pair of signal output units.

6. The detecting device for key operations of a keyboard device according to any one of claims 1 to 5, wherein The coils respectively included in the signal output units each have two spiral parts that are adjacent to and connected to each other, The spiral directions of the two spiral parts with respect to their respective centers are the same.

7. The detecting device for key operations of a keyboard device according to any one of claims 1 to 5, wherein The conductive part is a metal plate that is approximately parallel to the surface of the corresponding key.

8. The detecting device for key operations of a keyboard device according to any one of claims 1 to 5, wherein The conductive part is a circuit having a coil formed by connecting two spiral parts, The spiral directions of the two spiral parts of the conductive part with respect to their respective centers are the same.

9. A keyboard device, comprising: The detecting device for key operations according to any one of claims 1 to 5; and The plurality of keys.

10. A method for detecting key operations of a keyboard device, the keyboard device comprising: a conductive part provided on each of a plurality of keys; a substrate provided opposite to the plurality of keys in the pressing direction of the plurality of keys; and a plurality of signal output parts each having a coil, provided on the substrate corresponding to each of the plurality of keys, and outputting a signal corresponding to the following distance, which is the distance between the signal output part and the conductive part provided on the corresponding key. In the method for detecting key operations of the keyboard device, obtain signals output from the plurality of signal output units, based on the obtained signals, detect displacements in the front-rear direction of the corresponding keys.

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