Tactile sensation-granting device and tactile sensation-granting system
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- TAIYO YUDEN KK
- Filing Date
- 2024-11-13
- Publication Date
- 2026-05-25
AI Technical Summary
Existing devices for inducing gamma waves in users lack effective mechanisms to provide tactile sensations that enhance healing effects such as improving dementia and providing pleasant tactile experiences.
A tactile sensation-granting device and system that utilizes piezoelectric elements to apply amplitude-modulated or frequency-shift modulated vibrations at specific frequencies, including Solfeggio frequencies and gamma wave bands, to a housing, which is controlled by a computer system to induce desired tactile sensations.
The system provides users with tactile sensations that have healing effects, including improved dementia and a pleasant experience, by applying vibrations at specific frequencies, enhancing user interaction and sensory feedback.
Smart Images
Figure 2026085524000001_ABST
Abstract
Description
Technical Field
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[0001] The present disclosure relates to a tactile device and a tactile system.
Background Art
[0002] Various devices for inducing gamma waves in users have been proposed.
Prior Art Documents
Patent Documents
[0003] [Figure 1] This is a diagram showing a tactile feedback system according to the first embodiment. [Figure 2] This is a schematic diagram showing a tactile sensation-providing device in the first embodiment. [Figure 3] This is a cross-sectional view showing the actuator in the first embodiment. [Figure 4] This diagram shows the vibrations applied to the housing in the first example of the operation of the haptic feedback system. [Figure 5] This figure shows the vibrations applied to the housing in the second example of the operation of the haptic feedback system. [Figure 6] This is a cross-sectional view showing the actuator in the second embodiment. [Figure 7] This figure shows a tactile sensation-granting device in the third embodiment. [Figure 8] This is a cross-sectional view showing the actuator in the third embodiment. [Figure 9] This is a cross-sectional view showing a cylindrical body. [Figure 10] This is a cross-sectional view showing the fastening member. [Figure 11] This is a cross-sectional view showing a piezoelectric element in the third embodiment. [Modes for carrying out the invention]
[0009] The embodiments of this disclosure will be described in detail below, but this disclosure is not limited thereto. In this specification and drawings, components having substantially the same functional configuration may be denoted by the same reference numerals to avoid redundant descriptions. In the following description, the XYZ Cartesian coordinate system will be used, but this coordinate system is defined for illustrative purposes only and does not limit the orientation of the haptic device. Also, from any point, the +Z side may be referred to as upward, upper, or up, and the -Z side may be referred to as downward, lower, or down.
[0010] (First Embodiment) A first embodiment will be described. The first embodiment relates to a tactile sensation-granting system. Figure 1 is a diagram showing the tactile sensation-granting system according to the first embodiment. Figure 2 is a schematic diagram showing the tactile sensation-granting device in the first embodiment.
[0011] As shown in Figure 1, the tactile sensation imparting system 1 according to the first embodiment includes a tactile sensation imparting device 10 and a control device 20. The control device 20 controls the tactile sensation imparting device 10. The tactile sensation imparting device 10 is, for example, a fidget toy.
[0012] The control device 20 is a computer and includes a bus 21, an arithmetic processing unit 22, an input unit 23, an output unit 24, a storage device 25, and a memory device 26. The arithmetic processing unit 22, the input unit 23, the output unit 24, the storage device 25, and the memory device 26 are connected to the bus 21. The arithmetic processing unit 22, the input unit 23, the output unit 24, the storage device 25, and the memory device 26 are interconnected via the bus 21. The input unit 23 is a part for the user to input instructions, such as switches. The tactile feedback device 10 is connected to the output unit 24.
[0013] The storage device 25 stores a control program for controlling the haptic feedback device 10. The memory device 26 reads the control program from the storage device 25 and stores it when the control device 20 is started. The arithmetic processing unit 22 then, according to the control program stored in the memory device 26, causes the output unit 24 to output a drive signal to the haptic feedback device 10 in response to instructions input from the input unit 23.
[0014] As shown in Figure 2, the tactile feedback device 10 comprises a housing 11 and an actuator 100. The shape of the housing 11 is, for example, ellipsoidal. The housing 11 is large enough to be grasped by a person with one hand. The material of the housing 11 is, for example, polyacetal resin. The actuator 100 has a longitudinal direction along the Y axis. The actuator 100 is housed in the housing 11. For example, the actuator 100 is located at the center of the housing 11. The control device 20 may be located inside the housing 11, or it may be located outside the housing 11.
[0015] Here, the actuator 100 will be described. FIG. 3 is a cross-sectional view showing the actuator 100 in the first embodiment.
[0016] As shown in FIG. 3, the actuator 100 includes a diaphragm 12, an adhesive layer 13, and a piezoelectric element 110. The piezoelectric element 110 is fixed to one surface of the diaphragm 12 by the adhesive layer 13. The actuator 100 is an example of a first actuator. The piezoelectric element 110 is an example of a first piezoelectric element.
[0017] The piezoelectric element 110 includes a piezoelectric body 111, a first external electrode 114, a second external electrode 115, a plurality of first internal electrodes 112, a plurality of second internal electrodes 113, a first surface electrode 116, and a second surface electrode 117.
[0018] The piezoelectric body 111 has a plurality of piezoelectric body layers 118 laminated on each other. The piezoelectric body 111 has two end faces 111a and 111b perpendicular to the Y axis, two side faces (not shown) perpendicular to the X axis, and two main faces 111e and 111f perpendicular to the Z axis. For example, each face is configured in a substantially rectangular shape. The piezoelectric body 111 has a longitudinal direction along the Y axis.
[0019] The first external electrode 114 is disposed on the end face 111a of the piezoelectric body 111, and the second external electrode 115 is disposed on the end face 111b of the piezoelectric body 111. A plurality of first internal electrodes 112 and second internal electrodes 113 are disposed inside the piezoelectric body 111. The first surface electrode 116 is disposed on the main face 111e, and the second surface electrode 117 is disposed on the main face 1 / 1f.
[0020] The first internal electrode 112 and the second internal electrode 113 are alternately arranged along the Z-axis direction between a plurality of piezoelectric layers 118 stacked in the Z-axis direction. The first internal electrode 112 is connected to the first external electrode 114 and spaced apart from the second external electrode 115. The second internal electrode 113 is connected to the second external electrode 115 and spaced apart from the first external electrode 114. Adjacent first internal electrodes 112 and second internal electrodes 113 in the Z-axis direction can apply a driving voltage to the piezoelectric layer 118 between them. The first internal electrode 112 and the second internal electrode 113 are formed, for example, in a rectangular shape.
[0021] The first surface electrode 116 and the second surface electrode 117 are respectively arranged on the outermost piezoelectric layer 118. The first surface electrode 116 is located on the main surface 111e, and the second surface electrode 117 is located on the main surface 111f. The first surface electrode 116 is connected to the first external electrode 114 and spaced apart from the second external electrode 115. The second surface electrode 117 is connected to the second external electrode 115 and spaced apart from the first external electrode 114.
[0022] The first surface electrode 116 can apply a driving voltage to the piezoelectric layer 118 between it and the second internal electrode 113 closest to the main surface 111e. The second surface electrode 117 can apply a driving voltage to the piezoelectric layer 118 between it and the first internal electrode 112 closest to the main surface 111f. The piezoelectric layer 118 between the first surface electrode 116 and the outermost second internal electrode 113 may be a single layer or multiple layers. Similarly, the piezoelectric layer 118 between the second surface electrode 117 and the outermost first internal electrode 112 may be a single layer or multiple layers. The first surface electrode 116 and the second surface electrode 117 can increase the piezoelectric active region of the piezoelectric body 111, allowing the entire piezoelectric body 111 to expand and contract. The first surface electrode 116 and the second surface electrode 117 may be formed in a rectangular shape similar to the first internal electrode 112 and the second internal electrode 113, but they may also have a predetermined pattern. By applying a voltage between the first external electrode 114 and the second external electrode 115, the piezoelectric body 111 expands and contracts in the Y-axis direction due to the inverse piezoelectric effect. That is, in the piezoelectric element 110, expansion and contraction along the Y-axis direction is dominant, and the piezoelectric element 110 has a piezoelectric constant of d31. The piezoelectric layer 118 is an example of the first piezoelectric layer, the first internal electrode 112 and the first surface electrode 116 are examples of the first electrodes, and the second internal electrode 113 and the second surface electrode 117 are examples of the second electrodes. The Z-axis is an example of the first axis, and the Y-axis is an example of the second axis.
[0023] For the piezoelectric layer 118, for example, lead zirconate titanate (PZT:Pb(Zr,Ti)O3), barium titanate-based materials (BaTiO3, where Ba may be Ca and Ti may be Zr), bismuth titanate-based materials (BiTiO3, where part of Bi may be Na), and alkali niobate-based materials (NaNbO3, where Na may be Li or K) can be used. For the materials of the first internal electrode 112, second internal electrode 113, first external electrode 114, second external electrode 115, first surface electrode 116, and second surface electrode 117, for example, metals such as Ag, Pd, Pt, Cu, Ni, and Au can be used.
[0024] In the haptic feedback system 1, the actuator 100 vibrates under the control of the control device 20, and the actuator 100 applies vibration to the housing 11. As a result, the housing 11 also vibrates, and the user touching the housing 11 can feel the vibration.
[0025] Here, we will describe a first example of the operation of the haptic feedback system 1. Figure 4 shows the vibrations applied to the housing 11 in the first example of the operation of the haptic feedback system 1.
[0026] In the first example, as shown in Figure 4, the actuator 100 applies amplitude-modulated (AM-modulated) vibration to the housing 11. Specifically, the vibration applied by the actuator 100 has a carrier wave at a Solfeggio frequency and a modulated wave in the gamma wave band. In the example shown in Figure 4, the Solfeggio frequency is 174 Hz and the frequency of the modulated wave is 40 Hz, but it is not limited to these. For example, the Solfeggio frequency may be 63 Hz, 285 Hz, 396 Hz, 417 Hz, 528 Hz, or 963 Hz. From the viewpoint of suppressing vibration noise, it is preferable that the Solfeggio frequency is 528 Hz or less.
[0027] When the actuator 100 applies the first example of vibration to the housing 11, the user can feel vibrations in the Solfeggio frequency range and vibrations in the gamma wave band. Therefore, the user can be provided with vibrations that have healing effects such as those of the Solfeggio frequency range, and vibrations in the gamma wave band that have effects such as those of improving dementia. In this way, the tactile sensation application device 10 and the tactile sensation application system 1 can provide the user with a pleasant tactile sensation.
[0028] Next, a second example of the operation of the haptic feedback system 1 will be described. Figure 5 shows the vibrations applied to the housing 11 in the second example of the operation of the haptic feedback system 1.
[0029] In the second example, as shown in Figure 5, the actuator 100 applies frequency-shift modulated (FSK modulated) vibrations to the housing 11. Specifically, the vibrations applied by the actuator 100 alternate between a first wave of Solfeggio frequencies and a second wave in the gamma wave band. For example, the duration of the first wave vibration and the duration of the second wave vibration are equal. In the example shown in Figure 5, the frequency of the first wave is 174 Hz, the frequency of the second wave is 40 Hz, and the frequency at which the first and second waves switch is 4 Hz, but this is not limited to these frequencies. For example, the Solfeggio frequencies may be 63 Hz, 285 Hz, 396 Hz, 417 Hz, 528 Hz, or 963 Hz. From the viewpoint of suppressing vibration noise, it is preferable that the Solfeggio frequency is 528 Hz or less. Also, the frequency at which the first and second waves switch may be between 0.4 Hz and 4 Hz.
[0030] When the actuator 100 applies the vibrations of the second example to the housing 11, the user can feel vibrations of Solfeggio frequencies and vibrations in the gamma wave band, similar to the first example. Therefore, the user can be provided with vibrations that have healing effects such as those of Solfeggio frequencies, and vibrations in the gamma wave band that have effects such as improving dementia. Furthermore, since frequencies between 0.4Hz and 4Hz are close to the heartbeat frequency of small animals, if the frequency at which the first and second waves switch is between 0.4Hz and 4Hz, the user can be given a healing effect similar to that felt when holding a small animal.
[0031] (Second Embodiment) A second embodiment will now be described. The second embodiment differs from the first embodiment mainly in the configuration of the actuator. Figure 6 is a cross-sectional view showing the actuator in the second embodiment.
[0032] The vibration application system according to the second embodiment has an actuator 200 instead of actuator 100. As shown in Figure 6, the actuator 200 in the second embodiment includes a diaphragm 12, an adhesive layer 13, an adhesive layer 14, a piezoelectric element 110, and a piezoelectric element 120. The piezoelectric element 110 is fixed to one side of the diaphragm 12 by the adhesive layer 13. The piezoelectric element 120 is fixed to the other side of the diaphragm 12 by the adhesive layer 14. The piezoelectric element 120 has the same configuration as the piezoelectric element 110. Actuator 200 is an example of a first actuator. Piezoelectric element 120 is an example of a second piezoelectric element. In the piezoelectric element 120, the piezoelectric layer 118 is an example of a second piezoelectric layer, the first internal electrode 112 and the first surface electrode 116 are examples of a third electrode, and the second internal electrode 113 and the second surface electrode 117 are examples of a fourth electrode.
[0033] In the tactile feedback system according to the second embodiment, the control device 20 outputs a control signal to the tactile feedback device 10 such that the direction of expansion and contraction differs between the piezoelectric element 110 and the piezoelectric element 120. In other words, the actuator 200 is bimorph-driven.
[0034] Other configurations of the second embodiment are the same as those of the first embodiment, and, as in the first embodiment, AM-modulated or FSK-modulated vibrations are applied from the actuator 200 to the housing 11. The second embodiment also provides the same effects as the first embodiment.
[0035] (Third embodiment) A third embodiment will now be described. The third embodiment differs from the second embodiment mainly in the configuration of the tactile sensation-providing device. Figure 7 shows the tactile sensation-providing device in the third embodiment.
[0036] The vibration imparting system according to the third embodiment has a tactile imparting device 30 instead of the tactile imparting device 10. The tactile imparting device 30 is, for example, a fidget toy. As shown in Figure 7, the tactile imparting device 30 in the third embodiment has a housing 31, an actuator 200, and an actuator 300. The shape of the housing 31 is, for example, modeled after a rabbit. The housing 31 is large enough for a person to grasp with one hand. The material of the housing 31 is, for example, polyacetal resin. The actuators 200 and 300 are housed in the housing 31. For example, the actuator 200 is positioned at the center of the housing 31 in the Z-axis and X-axis directions, and offset from the center to the -Y side in the Y-axis direction, while the actuator 300 is positioned to the +Y side of the actuator 200. The actuator 300 has a longitudinal direction along the X-axis. Both ends of the actuator 300 in the longitudinal direction are roughly at the position of the rabbit's cheeks in the housing 31. The actuator 300 is an example of a second actuator.
[0037] Now, let's describe the actuator 300. Figure 8 is a cross-sectional view showing the actuator 300 in the third embodiment.
[0038] As shown in Figure 8, the actuator 300 includes piezoelectric elements 311 and 312, support members 321 and 322, and a housing 310. The actuator 300 generates vibrations, for example, in the ultrasonic band. The frequency of the ultrasonic band is, for example, 20 kHz or higher. The frequency of the ultrasonic band may be between 20 kHz and 60 kHz.
[0039] The housing 310 includes a cylindrical body 350 and fastening members 330 and 340. Figure 9 is a cross-sectional view showing the cylindrical body 350. Figure 10 is a cross-sectional view showing the fastening members 330 and 340. Figure 10(a) shows the fastening member 330, and Figure 10(b) shows the fastening member 340.
[0040] As shown in Figure 9, the cylindrical body 350 has a through hole 370 extending along the X-axis. The through hole 370 has a central part 371 and ends 372 and 373. End 372 is located on the +X side of the central part 371, and end 373 is located on the -X side of the central part 371.
[0041] The cross-sectional shape of the central part 371 perpendicular to the X-axis is approximately rectangular, while the cross-sectional shapes of the ends 372 and 373 perpendicular to the X-axis are approximately circular. A female thread 374 is formed on the inner surface of end 372, and a female thread 375 is formed on the inner surface of end 373. No threads are formed on the inner surface of the central part 371.
[0042] As shown in Figure 8, the piezoelectric elements 311 and 312 are arranged side by side along the X-axis within the central part 371. Piezoelectric element 311 is positioned on the +X side of piezoelectric element 312. Support member 321 is provided within end 372 on the +X side of piezoelectric element 311. Support member 322 is provided within end 373 on the -X side of piezoelectric element 312.
[0043] Thus, within the through-hole 370, the support member 321, piezoelectric element 311, piezoelectric element 312, and support member 322 are arranged in this order along the X-axis. For example, the support member 321, piezoelectric element 311, piezoelectric element 312, and support member 322 are separated from the inner surface of the through-hole 370 and do not contact the inner surface.
[0044] As shown in Figure 10(a), the fastening member 330 has a head 331 and a threaded portion 332. The cross-sectional shape of the head 331 perpendicular to the X-axis is approximately circular. A male thread 333 is formed on the outer surface of the threaded portion 332. The thread 333 fits into the thread 374 of the end portion 372. As shown in Figure 10(b), the fastening member 340 has a head 341 and a threaded portion 342. The cross-sectional shape of the head 341 perpendicular to the X-axis is approximately circular. A male thread 343 is formed on the outer surface of the threaded portion 342. The thread 343 fits into the thread 375 of the end portion 373. By tightening the screw, the fastening member 330 presses the support member 321 to the -X side, and the fastening member 340 presses the support member 322 to the +X side. As a result, compressive stress along the X-axis acts on the piezoelectric elements 311 and 312.
[0045] The material of the cylindrical body 350 and the fastening members 330 and 340 is, for example, metal or resin. The Young's modulus of the support members 321 and 322 is greater than the Young's modulus of the piezoelectric elements 311 and 312, the cylindrical body 350, and the fastening members 330 and 340. The material of the support members 321 and 322 is, for example, stainless steel, aluminum, or aluminum alloy.
[0046] Next, piezoelectric elements 311 and 312 will be described. Figure 11 is a cross-sectional view showing piezoelectric element 311 in the third embodiment. Piezoelectric element 312 has the same configuration as piezoelectric element 311.
[0047] As shown in Figure 11, the piezoelectric element 311 has a piezoelectric body 360 consisting of a plurality of piezoelectric layers 361, a plurality of third internal electrodes 362, and a plurality of fourth internal electrodes 364. The plurality of piezoelectric layers 361 are stacked in the X-axis direction. The piezoelectric layers 361, the third internal electrodes 362, and the fourth internal electrodes 364 are flat plates extending in the YZ plane. The plurality of third internal electrodes 362 and the plurality of fourth internal electrodes 364 are arranged alternately in the X-axis direction. One piezoelectric layer 361 is sandwiched between one third internal electrode 362 and one fourth internal electrode 364 in the X-axis direction. A third external electrode 363 is provided on the +Z side of the piezoelectric body 360, and a fourth external electrode 365 is provided on the -Z side of the piezoelectric body 360. The plurality of third internal electrodes 362 are electrically connected to the third external electrodes 363. Multiple fourth internal electrodes 364 are electrically connected to the fourth external electrode 365. By applying a voltage between the third external electrode 363 and the fourth external electrode 365, the piezoelectric body 360 expands and contracts in the X-axis direction due to the inverse piezoelectric effect. That is, in the piezoelectric element 311, expansion and contraction along the X-axis direction is dominant, and the piezoelectric element 311 has a piezoelectric constant of d33. Piezoelectric elements 311 and 312 are examples of third piezoelectric elements. Piezoelectric layer 361 is an example of a third piezoelectric layer, third internal electrode 362 is an example of a fifth electrode, and fourth internal electrode 364 is an example of a sixth electrode. The X-axis is an example of a third axis.
[0048] The piezoelectric element 360 comprises a fourth region 366, a fifth region 367, and a sixth region 368. The fourth region 366 and the fifth region 367 are arranged alternately in the X-axis direction. The sixth region 368 is located outside the outermost fourth region 366 in the X-axis direction. The fourth region 366 is a region in which the third internal electrode 362 and the fourth internal electrode 364 are arranged alternately at regular intervals in the X-axis direction. The number of piezoelectric layers 361 in the fourth region 366 is, as an example, 50 layers. The fifth region 367 and the sixth region 368 are regions in which the third internal electrode 362 and the fourth internal electrode 364 are not provided. The fifth region 367 may be omitted. Providing the fifth region 367 may improve reliability in some cases.
[0049] The material for the piezoelectric layer 361 can be the same as the material for the piezoelectric layer 118. The materials for the third internal electrode 362, the fourth internal electrode 364, the third external electrode 363, and the fourth external electrode 365 can be the same as the materials for the first internal electrode 112, the second internal electrode 113, the first external electrode 114, the second external electrode 115, the first surface electrode 116, and the second surface electrode 117.
[0050] Other configurations of the third embodiment are the same as those of the second embodiment, and similar to the second embodiment, AM-modulated or FSK-modulated vibrations are applied from the actuator 200 to the housing 31. Therefore, the same effects as the second embodiment can be obtained with the third embodiment. Furthermore, if a user touches the housing 31 near the longitudinal end of the actuator 300, ultrasonic vibrations generated by the actuator 300 are transmitted to the user. For example, the actuator 300 transmits a smooth, sliding sensation to the user.
[0051] The tactile feedback device 30 may also have an actuator 100 instead of actuator 200.
[0052] Although embodiments have been described in detail above, this disclosure is not limited to any particular embodiment, and various modifications and changes are possible within the scope of the claims.
[0053] The aspects of this disclosure are, for example, as follows:
[0054] <1> The casing and A first actuator housed in the aforementioned housing and which applies amplitude-modulated vibration to the housing, It has, The aforementioned vibration is The carrier wave of the Solfeggio frequencies, Modulated waves in the gamma wave band, A tactile sensory input device having the following features.
[0055] <2> The casing and A first actuator housed in the aforementioned housing and which applies frequency-shift modulated vibration to the housing, It has, The aforementioned vibration is The first wave of the Solfeggio frequencies, The second wave in the gamma wave band, A tactile sensory input device having alternating elements.
[0056] <3> In the vibration described above, the frequency at which the first wave and the second wave switch is between 0.4 Hz and 4 Hz. <2> The tactile sensation-granting device described above.
[0057] <4> The aforementioned Solfeggio frequencies are 528 Hz or lower. <1> from <3> A tactile sensation-granting device as described in any of the following.
[0058] <5> The first actuator has a first piezoelectric element, The first piezoelectric element is The first piezoelectric layer, A first electrode and a second electrode sandwich the first piezoelectric layer along the first axis, It has, By applying a voltage between the first electrode and the second electrode, the first piezoelectric layer expands and contracts along a second axis perpendicular to the first axis. <1> from <4> A tactile sensation-granting device as described in any of the following.
[0059] <6> The first actuator is A diaphragm having a first surface on which the first piezoelectric element is fixed and a second surface opposite to the first surface, A second piezoelectric element fixed to the second surface, It has, The second piezoelectric element is The second piezoelectric layer, A third electrode and a fourth electrode sandwich the second piezoelectric layer along the first axis, It has, By applying a voltage between the third electrode and the fourth electrode, the second piezoelectric layer expands and contracts along the second axis. <5> The tactile sensation-granting device described above.
[0060] <7> The housing has a second actuator housed within it, which applies vibration to the housing, The second actuator has a third piezoelectric element, The third piezoelectric element is The third piezoelectric layer, A fifth electrode and a sixth electrode sandwich the third piezoelectric layer along the third axis, It has, By applying a voltage between the fifth electrode and the sixth electrode, the third piezoelectric layer expands and contracts along the third axis. <1> from <6> A tactile sensation-granting device as described in any of the following.
[0061] <8> <1> from <7> A tactile sensation-granting device as described in any of the following, A control device for controlling the tactile sensation device, A tactile feedback system having the following features. [Explanation of Symbols]
[0062] 1. Tactile sensation granting system 10, 30 Tactile sensing devices 11, 31 cabinets 12 Diaphragm 13, 14 Adhesive layer 20 Control device 30. Tactile sensation-providing device 100, 200, 300 actuators
Claims
1. The casing and A first actuator housed in the aforementioned housing and which applies amplitude-modulated vibration to the housing, It has, The aforementioned vibration is The carrier wave of the Solfeggio frequencies, Modulated waves in the gamma wave band, A tactile sensory input device having the following features.
2. The casing and A first actuator housed in the aforementioned housing and which applies frequency-shift modulated vibration to the housing, It has, The aforementioned vibration is The first wave of the Solfeggio frequencies, The second wave in the gamma wave band, A tactile sensory input device having alternating elements.
3. The tactile sensation-providing device according to claim 2, wherein the frequency at which the first wave and the second wave switch in the vibration is 0.4 Hz or more and 4 Hz or less.
4. The tactile sensation-providing device according to any one of claims 1 to 3, wherein the Solfeggio frequency is 528 Hz or less.
5. The first actuator has a first piezoelectric element, The first piezoelectric element is The first piezoelectric layer, A first electrode and a second electrode sandwich the first piezoelectric layer along the first axis, It has, The tactile sensation-providing device according to any one of claims 1 to 3, wherein the first piezoelectric layer expands and contracts along a second axis perpendicular to the first axis by applying a voltage between the first electrode and the second electrode.
6. The first actuator is A diaphragm having a first surface on which the first piezoelectric element is fixed and a second surface opposite to the first surface, A second piezoelectric element fixed to the second surface, It has, The second piezoelectric element is The second piezoelectric layer, A third electrode and a fourth electrode sandwich the second piezoelectric layer along the first axis, It has, The tactile sensation-providing device according to claim 5, wherein the second piezoelectric layer expands and contracts along the second axis by applying a voltage between the third electrode and the fourth electrode.
7. The housing has a second actuator housed within it, which applies vibration to the housing, The second actuator has a third piezoelectric element, The third piezoelectric element is The third piezoelectric layer, A fifth electrode and a sixth electrode sandwich the third piezoelectric layer along the third axis, It has, The tactile sensation-providing device according to any one of claims 1 to 3, wherein the third piezoelectric layer expands and contracts along the third axis by applying a voltage between the fifth electrode and the sixth electrode.
8. A tactile sensation-granting device according to any one of claims 1 to 3, A control device for controlling the tactile sensation device, A tactile feedback system having the following features.