Vibration Device

Abstract

To provide a vibration device capable of generating tactile feedback and sound in response to operation of a user in spite of compact configuration.SOLUTION: In a vibration device 1, an operation unit 3 includes an operation surface which is operated by a user. A plurality of piezoelectric elements 10 are disposed so as to overlap the operation surface in a view in a direction orthogonal to the operation surface. The plurality of piezoelectric elements 10 are disposed at positions which are different from each other, in a direction along the operation surface. The control unit 5 controls the plurality of piezoelectric elements 10. In response to operation of the operation surface by the user, the control unit 5 vibrates, in a first frequency, the piezoelectric element 10 corresponding to a first position where the operation is performed on the operation surface among the plurality of piezoelectric elements 10 and vibrates, in a second frequency which is different from the first frequency, the piezoelectric element 10 corresponding to a second position which is different from the first position on the operation surface among the plurality of piezoelectric elements 10. The second frequency is a frequency in an audible range.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vibration device. [Background technology]

[0002] There is known a vibration device that includes an operation unit operated by a user and a piezoelectric element that vibrates in response to the operation of the operation unit by the user (for example, Patent Document 1). Patent Document 1 describes an electronic device that includes a display and a piezoelectric element. This piezoelectric element vibrates in response to the operation of the display by the user. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2018-536359 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 describes that an electronic device is provided with a composite element including a speaker in addition to the piezoelectric element. When a user operates an operation surface of an operation unit such as a display, this electronic device performs tactile feedback in the piezoelectric element of the composite element, and generates sound vibration in the speaker of the composite element to generate sound. However, in the composite element, the piezoelectric element and the speaker are arranged in the thickness direction of the display. With this configuration, it is difficult to reduce the size of the electronic device in the thickness direction of the operation surface such as a display.

[0005] An object of one aspect of the present invention is to provide a vibration device that has a compact configuration yet is capable of generating haptic feedback and sound in response to a user's operation. [Means for solving the problem]

[0006] A vibration device according to one aspect of the present invention includes an operation unit, a plurality of piezoelectric elements, and a control unit. The operation unit has an operation surface operated by a user. The plurality of piezoelectric elements are arranged so as to overlap with the operation surface when viewed from a direction perpendicular to the operation surface. The plurality of piezoelectric elements are arranged at different positions in a direction along the operation surface. The control unit controls the plurality of piezoelectric elements. In response to an operation of the operation surface by a user, the control unit vibrates a piezoelectric element among the plurality of piezoelectric elements that corresponds to a first position on the operation surface where the operation is performed at a first frequency, and vibrates a piezoelectric element among the plurality of piezoelectric elements that corresponds to a second position on the operation surface that is different from the first position at a second frequency that is different from the first frequency. The second frequency is a frequency in the audible range.

[0007] This vibration device includes a plurality of piezoelectric elements arranged at different positions along a direction along the operation surface. The control unit vibrates a piezoelectric element among the plurality of piezoelectric elements that corresponds to a first position on the operation surface where a user operates the operation surface. Furthermore, the control unit vibrates a piezoelectric element among the plurality of piezoelectric elements that corresponds to a second position on the operation surface different from the first position, at a frequency in the audible range. This vibration device can generate haptic feedback for the user by vibration of the piezoelectric element corresponding to the first position, and can generate sound by the piezoelectric element corresponding to the second position. Since the piezoelectric element that generates haptic feedback and the piezoelectric element that generates sound are arranged at different positions along the operation surface, the size is reduced in a direction perpendicular to the operation surface.

[0008] In the above aspect, each piezoelectric element may have a resonance frequency in the audible range. With this configuration, the sound pressure level of the sound emitted from the piezoelectric element corresponding to the second position is further improved.

[0009] In the above aspect, the first frequency at which the piezoelectric element corresponding to the first position is vibrated may be lower than a resonant frequency of the piezoelectric element, thereby improving the sensitivity of the haptic feedback to the user and further improving the sound pressure level of the sound emitted from the piezoelectric element corresponding to the second position.

[0010] In one aspect, the plurality of piezoelectric elements may include at least two piezoelectric elements having different resonant frequencies. The control unit may output a signal in which at least one of a waveform of a drive signal for vibrating the piezoelectric element corresponding to the first position, a strength of the drive signal, and a frequency of the drive signal are determined based on the resonant frequency of the piezoelectric element corresponding to the first position. With this configuration, the sound pressure level of the sound emitted from the piezoelectric element corresponding to the second position is ensured, and the sensitivity of the tactile feedback to the user can be improved.

[0011] In one of the above aspects, the plurality of piezoelectric elements may include a plurality of piezoelectric elements having a first resonant frequency and a plurality of piezoelectric elements having a second resonant frequency different from the first resonant frequency. With this configuration, even if any one of the plurality of piezoelectric elements is vibrating tactilely, the remaining plurality of piezoelectric elements have different resonant frequencies. Therefore, the sound pressure level is ensured over a wider frequency band.

[0012] In one of the above embodiments, the plurality of piezoelectric elements may include at least three piezoelectric elements each having a different resonance frequency. With this configuration, even if any one of the plurality of piezoelectric elements vibrates tactilely, the remaining piezoelectric elements include a plurality of piezoelectric elements each having a different resonance frequency. Therefore, the sound pressure level is ensured over a wider frequency band.

[0013] In one aspect, the control unit may determine, among the plurality of piezoelectric elements, a piezoelectric element corresponding to a first position, a piezoelectric element corresponding to a second position, and a piezoelectric element corresponding to a third position on the operation surface different from the first position and the second position. The control unit may not vibrate the piezoelectric element corresponding to the third position while vibrating the piezoelectric element corresponding to the first position and the piezoelectric element corresponding to the second position. With this configuration, sound is generated from an appropriate position depending on the situation.

[0014] In one aspect, the plurality of piezoelectric elements may be arranged in a matrix. When viewed from a direction perpendicular to the operation surface, the piezoelectric elements having the same resonance frequency may be adjacent to each other in the row direction. The piezoelectric elements having different resonance frequencies may be adjacent to each other in the column direction. With this configuration, the wiring for the piezoelectric elements can be simplified. Therefore, the size of the vibration device can be further reduced.

[0015] In one aspect, the plurality of piezoelectric elements may be arranged in a matrix such that the piezoelectric elements having different resonant frequencies are adjacent to each other in the row and column directions when viewed from a direction perpendicular to the operation surface. In this configuration, the piezoelectric elements having different resonant frequencies are positioned in a dispersed manner, so that the vibration device emits sound with an equal sound pressure level in each direction. Effect of the Invention

[0016] One aspect of the present invention provides a vibration device that has a compact configuration and is capable of generating haptic feedback and sound in response to a user's operation. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is a block diagram of a vibration device according to the present embodiment. [Diagram 2] FIG. 2 is a plan view of the vibration device. [Diagram 3] FIG. 2 is a cross-sectional view of a vibration device. [Figure 4]5 is a diagram for explaining control of a piezoelectric element by a control unit. FIG. [Diagram 5] 5(a) to 5(d) are diagrams illustrating a drive signal that drives a piezoelectric element. [Figure 6] FIG. 2 is a diagram for explaining the arrangement of piezoelectric elements. [Figure 7] FIG. 4 is a diagram for explaining wiring for a piezoelectric element. [Figure 8] 13A and 13B are diagrams for explaining the arrangement of piezoelectric elements in a modified example of the present embodiment. [Figure 9] 1A and 1B are diagrams illustrating an operation of a vibration device. [Figure 10] 1A and 1B are diagrams illustrating an operation of a vibration device. [Figure 11] 4A to 4D are diagrams illustrating the resonance frequency of a piezoelectric element. [Figure 12] 13A and 13B are diagrams for explaining the positions of operating piezoelectric elements in a vibration device according to a modified example of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or equivalent elements are designated by the same reference numerals, and duplicated explanations will be omitted.

[0019] First, the configuration of a vibration device according to this embodiment will be described with reference to Fig. 1 to Fig. 4. Fig. 1 is a block diagram of the vibration device. Fig. 2 is a plan view of the vibration device. Fig. 3 is a cross-sectional view of the vibration device.

[0020] The vibration device 1 generates haptic feedback and sound in response to a user's operation. The vibration device 1 is used in electronic devices such as mobile phone terminals, smartphones, personal computers, and tablet terminals. The vibration device 1 includes a housing 2, an operation unit 3, a plurality of vibration units 4, and a control unit 5. The vibration device 1 may further include a display and function as a touch panel display. In this case, the operation unit 3 may be the display. The vibration device 1 may be a tablet that does not include a display.

[0021] 2, the operation unit 3 is fitted into the housing 2. The vibration device 1 has an accommodation space S formed by the housing 2 and the operation unit 3. A plurality of vibration units 4 are accommodated in the accommodation space S. In this embodiment, the vibration device 1 has a plate shape, and the operation unit 3 also has a plate shape.

[0022] The operation unit 3 has an operation surface 3a operated by a user. The operation unit 3 outputs a signal according to the operation of the operation surface 3a by the user to the control unit 5. The operation unit 3 outputs a signal including position information on the operation surface 3a touched by the user to the control unit 5. The "operation of the operation surface" includes at least one of a case where the user operates the operation surface 3a with a part of the user's body such as a finger, and a case where the user operates the operation surface 3a with an operation member such as a stylus pen. The "touch operation" includes an operation in which the user's body or the operation member applies force to the operation surface, and an operation in which the user's body or the operation member touches the operation surface and does not apply force to the operation surface. The operation unit 3 includes, for example, an electrostatic touch sensor, and transmits information on the position on the operation surface 3a where a part of the user's body is touching to the control unit 5 by the above signal. The operation unit 3 may include a piezoelectric touch sensor instead of the electrostatic touch sensor.

[0023] The vibration units 4 perform haptic vibration for providing haptic feedback and sound vibration for emitting sound in response to a drive signal from the control unit 5. The vibration units 4 are arranged so as to overlap with the operation surface 3a when viewed from a direction perpendicular to the operation surface 3a. The vibration units 4 are arranged along the operation surface 3a in the accommodation space S. In this embodiment, the vibration units 4 are two-dimensionally arranged in a matrix along the operation surface 3a when viewed from a direction perpendicular to the operation surface 3a. In this embodiment, the operation surface 3a is rectangular, and 12 vibration units 4 are arranged in 3 rows and 4 columns. The vibration units 4 may be arranged on a straight line extending along the operation surface 3a.

[0024] Each vibration section 4 has a piezoelectric element 10 and a vibration plate 15. The piezoelectric elements 10 are arranged so as to overlap with the operation surface 3a when viewed from a direction perpendicular to the operation surface 3a. The piezoelectric elements 10 are provided on the vibration plate 15. In this embodiment, one piezoelectric element 10 is bonded to one vibration plate 15. In this embodiment, the piezoelectric element 10 and the vibration plate 15 have a circular shape when viewed from a direction perpendicular to the operation surface 3a. The vibration plate 15 is larger than the piezoelectric element 10 in a plan view. When viewed from a direction perpendicular to the operation surface 3a, the edge of the vibration plate 15 surrounds the edge of the piezoelectric element 10 bonded to the vibration plate 15.

[0025] The piezoelectric elements 10 are displaced in response to a drive signal from the control unit 5. The direction of displacement of each piezoelectric element 10 by the drive signal from the control unit 5 includes a component in a direction perpendicular to the operation surface 3a. In other words, each piezoelectric element 10 is displaced in the thickness direction of the vibration device 1. The piezoelectric elements 10 repeat displacement in response to the frequency of the drive signal. The vibration plate 15 vibrates due to the force transmitted from the piezoelectric elements 10.

[0026] In the vibration device 1, each vibration section 4 includes one piezoelectric element 10. Therefore, in the vibration device 1, a plurality of piezoelectric elements 10 are arranged in the accommodation space S along the operation surface 3a. In other words, the plurality of piezoelectric elements 10 are arranged at different positions from each other in a direction along the operation surface 3a. In this embodiment, the plurality of piezoelectric elements 10 are two-dimensionally arranged in a matrix along the operation surface 3a when viewed from a direction perpendicular to the operation surface 3a.

[0027] Each piezoelectric element 10 has a resonant frequency in the audible range. The resonant frequency of the plurality of piezoelectric elements 10 is 20 Hz to 20,000 Hz. In this embodiment, each piezoelectric element 10 is configured to have a resonant frequency of 3,000 Hz to 10,000 Hz. The plurality of piezoelectric elements 10 are divided into a plurality of groups having mutually different resonant frequencies. That is, the plurality of piezoelectric elements 10 includes at least two piezoelectric elements 10 having mutually different resonant frequencies.

[0028] The piezoelectric element 10 has a piezoelectric body 11 and a pair of external electrodes 12, 13. The piezoelectric body 11 is configured by laminating a plurality of piezoelectric layers (not shown). Each piezoelectric layer is made of a piezoelectric material. In this embodiment, each piezoelectric layer is made of a piezoelectric ceramic material. For example, PZT [Pb (Zr, Ti) O3], PT (PbTiO3), PLZT [(Pb, La) (Zr, Ti) O3], or barium titanate (BaTiO3) is used as the piezoelectric ceramic material. Each piezoelectric layer is made of, for example, a sintered ceramic green sheet containing the above-mentioned piezoelectric ceramic material. In the actual piezoelectric body 11, each piezoelectric layer is integrated to such an extent that the boundaries between the piezoelectric layers cannot be recognized. A plurality of internal electrodes (not shown) are arranged in the piezoelectric body 11. Each internal electrode is made of a conductive material. For example, Ag, Pd, or an Ag-Pd alloy is used as the conductive material.

[0029] The vibration plate 15 is disposed between the corresponding piezoelectric element 10 and the housing 2. The vibration plate 15 has a pair of main surfaces 15a, 15b. The vibration plate 15 is bonded to the corresponding piezoelectric element 10 at the main surface 15a. The vibration plate 15 is supported by the housing 2 at the main surface 15b. A part of the main surface 15b of the vibration plate 15 is spaced apart from the housing 2. The vibration plate 15 is bonded to the housing 2 at an edge of the vibration plate 15. The center of the vibration plate 15 is spaced apart from the housing 2. The material of the vibration plate 15 includes at least one of brass, stainless steel, and nickel alloy, for example.

[0030] The control unit 5 controls the piezoelectric elements 10 of each vibration unit 4 in response to the operation of the operation surface 3a by the user. In this embodiment, the control unit 5 controls the vibration units 4 based on a signal output from the operation unit 3. The control unit 5 outputs a drive signal and controls the piezoelectric elements 10 by the drive signal. FIG. 4 is a diagram for explaining the control of the piezoelectric elements 10 by the control unit 5.

[0031] 4, the control unit 5, in response to the operation of the operation surface 3a by the user U, causes tactile vibration of the piezoelectric element 10 corresponding to a first position α where the operation is performed. The control unit 5, in response to the operation of the operation surface 3a by the user U, causes sound vibration of the piezoelectric element 10 corresponding to a second position β different from the first position α where the operation is performed. The first position α and the second position β are positions on the operation surface 3a. The first position α is a position on the operation surface 3a that is touched by the user U, and the second position β is a position on the operation surface 3a that is not touched by the user U.

[0032] In this embodiment, the piezoelectric element 10 corresponding to the first position α is a piezoelectric element 10 arranged at a position overlapping the first position α when viewed from a direction perpendicular to the operation surface 3a. The piezoelectric element 10 corresponding to the second position β is a piezoelectric element 10 arranged at a position overlapping the second position β when viewed from a direction perpendicular to the operation surface 3a. The piezoelectric element 10 corresponding to the first position α is one piezoelectric element 10, and the piezoelectric element 10 corresponding to the second position β is a plurality of piezoelectric elements 10. In this embodiment, the control unit 5 causes tactile vibration of the piezoelectric element 10 located directly below the position on the operation surface 3a that the user U touches in response to the operation of the operation surface 3a by the user U, and causes the plurality of piezoelectric elements 10 to vibrate to produce sound. In this embodiment, the control unit 5 outputs a drive signal so that the plurality of piezoelectric elements 10 that vibrate to produce sound play a melody by changing the vibration frequency. The control unit 5 may output a drive signal so that the plurality of piezoelectric elements 10 that vibrate to produce sound generate a single sound.

[0033] The control unit 5 outputs a drive signal to the piezoelectric element 10 corresponding to the first position α so as to vibrate at a first frequency. The control unit 5 outputs a drive signal to the piezoelectric element 10 corresponding to the second position β so as to vibrate at a second frequency. The first frequency that vibrates the piezoelectric element 10 corresponding to the first position α is lower than the resonance frequency of the piezoelectric element 10. The first frequency is smaller than the second frequency. At least the second frequency is a frequency in the audible range. The first frequency is, for example, 50 Hz to 200 Hz. In this embodiment, the first frequency is 160 Hz. The second frequency is, for example, 20 Hz to 20,000 Hz. In this embodiment, the second frequency is 3,000 Hz to 10,000 Hz, and changes depending on the pitch of the sound generated by the piezoelectric element 10.

[0034] The control unit 5 may be accommodated in the accommodation space S, or may be provided outside the accommodation space S. The control unit 5 may be separated from the housing 2 and the operation unit 3. The control unit 5 has an acquisition unit 21, a piezoelectric element determination unit 22, a tactile signal generation unit 23, and a sound signal generation unit 24.

[0035] The acquisition unit 21 acquires a signal corresponding to an operation on the operation surface 3a by the user U. The signal includes position information on the position on the operation surface 3a where the user U performed a touch operation. In this embodiment, the acquisition unit 21 acquires a signal output from the operation unit 3.

[0036] The piezoelectric element determination unit 22 selects the piezoelectric element 10 to be operated in response to the signal acquired by the acquisition unit 21. In other words, the piezoelectric element determination unit 22 determines the piezoelectric element 10 corresponding to the first position α and the piezoelectric element 10 corresponding to the second position β in response to the signal acquired by the acquisition unit 21.

[0037] The haptic signal generating unit 23 generates a drive signal that causes the piezoelectric element 10 to haptically vibrate. The haptic signal generating unit 23 outputs the generated drive signal to the piezoelectric element 10 that corresponds to the first position α determined by the piezoelectric element determining unit 22. In other words, the haptic signal generating unit 23 generates a drive signal that causes the piezoelectric element 10 to vibrate at a first frequency, and outputs the drive signal to the piezoelectric element 10 that corresponds to the first position α. ​​In this embodiment, the haptic signal generating unit 23 acquires the resonance frequency of the piezoelectric element 10 that corresponds to the first position α, and determines at least one of the waveform of the drive signal that causes the piezoelectric element 10 to haptically vibrate, the intensity of the drive signal, and the frequency of the drive signal according to the acquired resonance frequency.

[0038] As a modification of this embodiment, the haptic signal generating unit 23 may read out from the storage unit a drive signal determined based on the resonant frequency of the piezoelectric element 10 corresponding to the first position α and output the drive signal. In this case, the associated drive signal may be stored in the storage unit in advance, for example, with at least one of the waveform, intensity, and frequency of the drive signal and the resonant frequency associated with each other. The haptic signal generating unit 23 may obtain the drive signal determined based on the resonant frequency of the piezoelectric element 10 corresponding to the first position α from a device external to the vibration device and output the drive signal.

[0039] 5(a) to 5(d) show an example of a drive signal that causes the piezoelectric element 10 to vibrate in a tactile manner. FIG. 5(a) shows an example of a waveform of a reference drive signal. FIG. 5(b) shows an example of a drive signal whose waveform is changed from the reference drive signal. The drive signal shown in FIG. 5(b) has a triangular waveform, whereas the drive signal shown in FIG. 5(a) has a waveform closer to a sine wave than the drive signal shown in FIG. 5(b). FIG. 5(c) shows an example of a drive signal whose intensity is changed from the reference drive signal. The intensity of the drive signal shown in FIG. 5(c) is greater than the intensity of the drive signal shown in FIG. 5(b). FIG. 5(d) shows an example of a drive signal whose frequency is changed from the reference drive signal. The frequency of the drive signal shown in FIG. 5(d) is greater than the frequency of the drive signal shown in FIG. 5(a).

[0040] The sound signal generating unit 24 generates a drive signal that vibrates the piezoelectric element 10 to produce sound. The sound signal generating unit 24 outputs the generated drive signal to the piezoelectric element 10 corresponding to the second position β determined by the piezoelectric element determining unit 22. In other words, the tactile signal generating unit 23 generates a drive signal that vibrates the piezoelectric element 10 at the second frequency, and outputs the drive signal to the piezoelectric element 10 corresponding to the second position β.

[0041] Next, an example of the configuration of the piezoelectric element 10 in the vibration device 1 will be described in detail with reference to Fig. 6 and Fig. 7. Fig. 6 shows the arrangement of the piezoelectric element 10 as viewed from a direction perpendicular to the operation surface 3a. Fig. 7 shows a part of the wiring for the piezoelectric element 10 in this embodiment.

[0042] In the vibration device 1 shown in Fig. 6, the plurality of piezoelectric elements 10 includes three groups of piezoelectric elements 10 having different resonant frequencies. In other words, the plurality of piezoelectric elements 10 includes at least three piezoelectric elements 10 each having a different resonant frequency. The plurality of piezoelectric elements 10 includes a plurality of piezoelectric elements A having a first resonant frequency, a plurality of piezoelectric elements B having a second resonant frequency, and a plurality of piezoelectric elements C having a third resonant frequency.

[0043] In the vibration device 1 shown in Fig. 6, the multiple piezoelectric elements 10 are arranged in a matrix of 3 rows and 4 columns. When viewed from a direction perpendicular to the operation surface 3a, the piezoelectric elements having the same resonance frequency are arranged adjacent to each other in the row direction. When viewed from a direction perpendicular to the operation surface 3a, the piezoelectric elements having different resonance frequencies are arranged adjacent to each other in the column direction and the row direction.

[0044] For example, multiple piezoelectric elements A are arranged in the row direction adjacent to each other without piezoelectric elements B and C sandwiched between them. Multiple piezoelectric elements B are arranged in the row direction adjacent to each other without piezoelectric elements A and C sandwiched between them. Multiple piezoelectric elements C are arranged in the row direction adjacent to each other without piezoelectric elements A and B sandwiched between them. A row in which multiple piezoelectric elements B are arranged is located adjacent to a row in which multiple piezoelectric elements A are arranged. A row in which multiple piezoelectric elements C are arranged is located adjacent to a row in which multiple piezoelectric elements B are arranged. Multiple piezoelectric elements 10 are arranged in the column direction in the order of piezoelectric element A, piezoelectric element B, and piezoelectric element C.

[0045] 7 shows a wiring structure for the piezoelectric elements 10 in the vibration device 1 shown in FIG. 6. FIG. 7 shows the vibration device 1 excluding the operation unit 3. Each piezoelectric element 10 is connected to a pair of wirings 31, 32 that transmit a drive signal for tactilely vibrating the piezoelectric element 10, and a pair of wirings 33, 34 that transmit a signal for sound-producing vibration of the piezoelectric element 10. Piezoelectric elements 10 having the same resonance frequency are connected in parallel by the same wirings 31, 33. The wirings 31, 32, 33, 34 connected to piezoelectric elements 10 having the same resonance frequency extend in the row direction between adjacent piezoelectric elements 10.

[0046] The wirings 32 and 34 connected to the piezoelectric elements A extend in the row direction between a group of the piezoelectric elements A and a group of the piezoelectric elements B. The wirings 31 and 33 connected to the piezoelectric elements B extend in the row direction between a group of the piezoelectric elements A and a group of the piezoelectric elements B. The wirings 32 and 34 connected to the piezoelectric elements B extend in the row direction between a group of the piezoelectric elements B and a group of the piezoelectric elements C. The different wirings 31, 32, 33, and 34 are arranged so as not to overlap each other when viewed from a direction perpendicular to the operation surface 3a. The direction in which the wirings 31 and 32 extend from each piezoelectric element 10 is opposite to the direction in which the wirings 33 and 34 extend from each piezoelectric element 10.

[0047] As a modified example of this embodiment, the plurality of piezoelectric elements 10 may be arranged so that the piezoelectric elements having the same resonance frequency are distributed. FIG. 8 shows the arrangement of the piezoelectric elements 10 in the modified example of this embodiment as viewed from a direction perpendicular to the operation surface 3a. In the vibration device 1 shown in FIG. 8, the plurality of piezoelectric elements 10 are arranged in a matrix such that the piezoelectric elements having different resonance frequencies are adjacent to each other in the row direction and the column direction as viewed from a direction perpendicular to the operation surface 3a. In the vibration device 1 shown in FIG. 8, a row in which the piezoelectric elements 10 are arranged in the row direction in the order of piezoelectric element C, piezoelectric element A, piezoelectric element B, piezoelectric element C is located next to a row in which the piezoelectric elements 10 are arranged in the row direction in the order of piezoelectric element A, piezoelectric element B, piezoelectric element C, piezoelectric element A. A row in which the piezoelectric elements 10 are arranged in the row direction in the order of piezoelectric element B, piezoelectric element C, piezoelectric element A, piezoelectric element B is located next to a row in which the piezoelectric elements 10 are arranged in the row direction in the order of piezoelectric element C, piezoelectric element A, piezoelectric element B, piezoelectric element C.

[0048] Next, the operation of the vibration device 1 will be described with reference to Fig. 4 and Fig. 9 to Fig. 12. Fig. 9 and Fig. 10 are diagrams for explaining the operation of the vibration device. Fig. 11(a) to Fig. 11(d) show frequency characteristics of the piezoelectric element. Fig. 12 is a diagram for explaining the position of the operating piezoelectric element.

[0049] 9, in the vibration device 1, when the user U operates the operation surface 3a of the operation unit 3, the piezoelectric element 10 located directly below the position on the operation surface 3a operated by the user U produces tactile vibration. The tactile vibration of the piezoelectric element 10 is transmitted to the user U via the operation unit 3. As a result, the user U receives tactile feedback in accordance with the operation of the operation unit 3.

[0050] 10, in the vibration device 1, when the user U operates the operation surface 3a of the operation unit 3, a piezoelectric element 10 different from the piezoelectric element 10 that has undergone haptic vibration vibrates to produce sound. In this embodiment, a melody is generated from the operation surface 3a by the multiple piezoelectric elements 10 vibrating to produce sound. The multiple piezoelectric elements 10 that vibrate to produce sound include piezoelectric elements A, B, and C having different resonance frequencies from each other.

[0051] FIG. 11(a) shows the frequency characteristic of the piezoelectric element A. FIG. 11(b) shows the frequency characteristic of the piezoelectric element B. FIG. 11(c) shows the frequency characteristic of the piezoelectric element C. As shown in FIG. 11(a) to FIG. 11(c), the frequency characteristics of the piezoelectric elements A, B, and C have peaks at different frequencies. Therefore, when the frequency characteristics of the piezoelectric elements A, B, and C are synthesized, a waveform as shown in FIG. 11(d) is obtained. This synthesized waveform has a larger peak width than the waveforms of the frequency characteristics of each of the piezoelectric elements A, B, and C. Therefore, when the control unit 5 simultaneously vibrates the piezoelectric elements A, B, and C to generate sound, a sound pressure level is ensured in a wider frequency band than when the piezoelectric elements A, B, and C are vibrated individually to generate sound.

[0052] 4, in this embodiment, the piezoelectric element determination unit 22 of the control unit 5 determines the piezoelectric element 10 arranged at a position overlapping with the first position α where the user U has performed an operation, as the piezoelectric element 10 corresponding to the first position α, as viewed from a direction perpendicular to the operation surface 3a. The piezoelectric element determination unit 22 determines all the piezoelectric elements 10, except for the piezoelectric element 10 corresponding to the first position α, among the multiple piezoelectric elements 10 included in the vibration device 1, as the piezoelectric element 10 corresponding to the second position β. In other words, the second position β is the entire region on the operation surface 3a except for the first position α.

[0053] As a modification of this embodiment, the control unit 5 may not vibrate some of the piezoelectric elements 10 included in the vibration device 1. For example, as shown in FIG. 12, the control unit 5 vibrates the piezoelectric element 10 corresponding to the first position α for tactile vibration, vibrates the piezoelectric element 10 corresponding to the second position β for sound vibration, and does not vibrate the piezoelectric element 10 corresponding to a third position γ different from the first position α and the second position β on the operation surface 3a. While vibrating the piezoelectric element 10 corresponding to the first position α and the piezoelectric element 10 corresponding to the second position β, the control unit 5 does not vibrate the piezoelectric element 10 corresponding to the third position γ. For example, the control unit 5 prohibits the vibration of the piezoelectric element 10 corresponding to the third position γ until the position operated by the user U is changed.

[0054] In this modification, the second position β is a position previously associated with the first position α. ​​For example, the vibration device 1 stores relative position information of the second position β with respect to the first position α in a memory (not shown) in advance. When the piezoelectric element 10 corresponding to the first position α is determined, the piezoelectric element determination unit 22 of the control unit 5 acquires the relative position information, and determines the piezoelectric element 10 corresponding to the second position β based on the relative position information and the determined first position α or the piezoelectric element 10 corresponding to the first position α.

[0055] For example, the piezoelectric element determination unit 22 of the control unit 5 determines the piezoelectric element 10 arranged at a position overlapping with the first position α where the user U performed the operation as viewed from a direction perpendicular to the operation surface 3a as the piezoelectric element 10 corresponding to the first position α. ​​The piezoelectric element determination unit 22 determines, for example, the piezoelectric elements 10 adjacent to the piezoelectric element 10 corresponding to the first position α in four or eight directions as the piezoelectric element 10 corresponding to the second position β among the plurality of piezoelectric elements 10 included in the vibration device 1 as the piezoelectric element 10 corresponding to the second position β. The "four directions" refers to the vertical and horizontal directions on the operation surface 3a. The "eight directions" refers to the vertical, horizontal and diagonal directions on the operation surface 3a. The piezoelectric element determination unit 22 determines all the piezoelectric elements 10 except the piezoelectric element 10 corresponding to the first position α and the piezoelectric element 10 corresponding to the second position β among the plurality of piezoelectric elements 10 included in the vibration device 1 as the piezoelectric element 10 corresponding to the third position γ.

[0056] As described above, the vibration device 1 includes a plurality of piezoelectric elements 10 arranged at different positions in a direction along the operation surface 3a. The control unit 5 vibrates the piezoelectric element 10 corresponding to the first position α on the operation surface 3a where the user U has performed an operation, among the plurality of piezoelectric elements 10. Furthermore, the control unit 5 vibrates the piezoelectric element 10 corresponding to the second position β on the operation surface 3a, which is different from the first position α, among the plurality of piezoelectric elements 10, at an audible frequency. This vibration device 1 can generate haptic feedback for the user U by the vibration of the piezoelectric element 10 corresponding to the first position α, and can generate sound by the piezoelectric element 10 corresponding to the second position β. Since the piezoelectric element 10 that generates haptic feedback and the piezoelectric element 10 that generates sound are arranged at different positions in a direction along the operation surface 3a, the size is reduced in a direction perpendicular to the operation surface 3a.

[0057] The piezoelectric elements 10 are arranged so as to overlap with the operation surface 3a when viewed from a direction perpendicular to the operation surface 3a. This allows the user U to feel as if sound is being emitted from the operation surface 3a. In other words, the vibration device 1 has a compact configuration, yet can provide the user U with tactile feedback and a sense of realism through sound.

[0058] Each piezoelectric element 10 has a resonance frequency in the audible range. With this configuration, the sound pressure level of the sound emitted from the piezoelectric element 10 corresponding to the second position β is further improved.

[0059] The first frequency that vibrates the piezoelectric element 10 corresponding to the first position α is lower than the resonance frequency of the piezoelectric element 10. With this configuration, the sensitivity of the tactile feedback by the user U is improved, and the sound pressure level of the sound emitted from the piezoelectric element 10 corresponding to the second position β is further improved.

[0060] The plurality of piezoelectric elements 10 includes at least two piezoelectric elements 10 having different resonant frequencies. The control unit 5 outputs a signal in which at least one of the waveform of a drive signal for vibrating the piezoelectric element 10 corresponding to the first position α, the intensity of the drive signal, and the frequency of the drive signal are determined based on the resonant frequency of the piezoelectric element 10 corresponding to the first position α. ​​With this configuration, the sound pressure level of the sound emitted from the piezoelectric element 10 corresponding to the second position β is ensured, and the sensitivity of the user U to haptic feedback can be improved.

[0061] The plurality of piezoelectric elements 10 includes a plurality of piezoelectric elements 10 having a first resonant frequency and a plurality of piezoelectric elements 10 having a second resonant frequency different from the first resonant frequency. With this configuration, even if any one of the plurality of piezoelectric elements 10 is vibrating tactilely, the remaining piezoelectric elements 10 include a plurality of piezoelectric elements 10 having different resonant frequencies. Therefore, the sound pressure level is ensured over a wider frequency band. Therefore, the vibration device 1 can ensure the sound pressure level of each pitch and can also emit a melody from the piezoelectric element 10 corresponding to the second position β.

[0062] The plurality of piezoelectric elements 10 includes at least three piezoelectric elements 10 each having a different resonant frequency. According to this configuration, even if any one of the plurality of piezoelectric elements 10 is vibrating tactilely, the remaining piezoelectric elements 10 include a plurality of piezoelectric elements 10 each having a different resonant frequency. Therefore, the sound pressure level is ensured in a wider frequency band. Therefore, the vibration device 1 can ensure the sound pressure level of each pitch and can also emit a melody from the piezoelectric element 10 corresponding to the second position β.

[0063] The control unit 5 determines, among the multiple piezoelectric elements 10, the piezoelectric element 10 corresponding to the first position α, the piezoelectric element 10 corresponding to the second position β, and the piezoelectric element 10 corresponding to a third position γ on the operation surface 3a that is different from the first position α and the second position β. While the control unit 5 vibrates the piezoelectric element 10 corresponding to the first position α and the piezoelectric element 10 corresponding to the second position β, it does not vibrate the piezoelectric element 10 corresponding to the third position γ. With this configuration, sound is generated from an appropriate position depending on the situation.

[0064] The piezoelectric elements 10 are arranged in a matrix. When viewed from a direction perpendicular to the operation surface 3a, the piezoelectric elements 10 having the same resonance frequency are adjacent to each other in the row direction. The piezoelectric elements 10 having different resonance frequencies are adjacent to each other in the column direction. With this configuration, the wiring 31, 32, 33, and 34 for the piezoelectric elements 10 can be simplified. Therefore, the size of the vibration device 1 can be further reduced.

[0065] The piezoelectric elements 10 are arranged in a matrix such that the piezoelectric elements 10 having different resonance frequencies are adjacent to each other in the row and column directions when viewed from a direction perpendicular to the operation surface 3a. In this configuration, the piezoelectric elements 10 having different resonance frequencies are positioned in a scattered manner, so that the vibration device 1 emits sound with an equal sound pressure level in each direction.

[0066] Although the embodiments and modifications of the present invention have been described above, the present invention is not necessarily limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present invention.

[0067] For example, the piezoelectric element 10 may be displaced by a force transmitted through the operation unit 3 pressed by the user U, and an electric signal generated by this displacement may be output to the control unit 5. In this case, the control unit 5 may control a plurality of vibration units 4 based on the signals output from the piezoelectric elements 10. For example, the control unit 5 detects from which piezoelectric element 10 the signal is output from the signal output from the piezoelectric element 10, and acquires position information on the operation surface 3a where the user U performed the touch operation. The acquisition unit 21 of the control unit 5 acquires the signal output from the piezoelectric element 10 or the position information of the piezoelectric element 10. The piezoelectric element determination unit 22 of the control unit 5 determines the piezoelectric element 10 corresponding to the first position α and the piezoelectric element 10 corresponding to the second position β based on the position information.

[0068] In the vibration device 1 shown in Figures 6, 7, and 8, the multiple piezoelectric elements 10 are made up of three groups of piezoelectric elements 10 having different resonant frequencies. However, the multiple piezoelectric elements 10 may be made up of two groups of piezoelectric elements 10 having different resonant frequencies. The multiple piezoelectric elements 10 may be made up of four or more groups of piezoelectric elements 10 having different resonant frequencies.

[0069] 6 and 7, the piezoelectric elements 10 having different resonant frequencies are arranged in each row. However, the piezoelectric elements 10 having different resonant frequencies may be arranged in multiple rows. For example, the multiple piezoelectric elements 10 may be arranged in the following order in the column direction: piezoelectric element A, piezoelectric element A, piezoelectric element B, piezoelectric element B, piezoelectric element C, and piezoelectric element C.

[0070] 6 and 7, the long side direction of the operation surface 3a is the row direction, and the short side direction is the column direction. However, the long side direction of the operation surface 3a may be the column direction, and the short side direction may be the row direction.

[0071] In the vibration device 1 shown in Fig. 8, the piezoelectric elements 10 having the same resonant frequency are arranged regularly so as to be spaced apart. However, the piezoelectric elements 10 having the same resonant frequency may be arranged irregularly. For example, the arrangement of the multiple piezoelectric elements 10 may be randomly determined by software or the like.

[0072] The control unit 5 may cause the piezoelectric element 10 corresponding to the first position α to perform sound vibration together with the haptic vibration. For example, the control unit 5 may cause the piezoelectric element 10 located immediately below the position operated by the user U to perform vibration that emits sound together with other piezoelectric elements 10, and this vibration may be transmitted to the user U via the operation surface 3a. The control unit 5 may cause the piezoelectric element 10 located immediately below the position operated by the user U to perform sound vibration immediately after performing the haptic vibration. [Explanation of symbols]

[0073] 1...vibration device, 3...operation unit, 3a...operation surface, 5...control unit, 10, A, B, C...piezoelectric element, U...user, α...first position, β...second position, γ...third position.

Claims

1. an operation unit having an operation surface operated by a user; The piezoelectric element includes a plurality of first piezoelectric elements and a plurality of second piezoelectric elements having frequency characteristics with mutually different peak frequencies, the plurality of piezoelectric elements being arranged so as to overlap with the operation surface when viewed from a direction perpendicular to the operation surface, and being arranged at mutually different positions in a direction along the operation surface; A control unit that controls the plurality of piezoelectric elements, Each of the plurality of piezoelectric elements is a piezoelectric element that performs tactile vibration and sound vibration in response to control of the control unit, The control unit, in response to operation of the operation surface by the user, tactilely vibrates, at a first frequency, a piezoelectric element among the plurality of piezoelectric elements that is arranged at a position that overlaps with the operation position on the operation surface where the operation is performed by the user, when viewed from a direction perpendicular to the operation surface, and in parallel with the tactile vibration, simultaneously audibly vibrates, at a second frequency that is different from the first frequency and is an audible frequency having a waveform that is a combination of the waveform of the frequency characteristics of the first piezoelectric element and the waveform of the frequency characteristics of the second piezoelectric element.

2. The vibration device according to claim 1 , wherein each of the piezoelectric elements has a resonant frequency in the audible range.

3. The vibration device according to claim 2 , wherein a first frequency for vibrating the piezoelectric element disposed at a position overlapping the operation position is lower than a resonant frequency of the piezoelectric element.

4. The plurality of piezoelectric elements includes at least two piezoelectric elements having different resonant frequencies, A vibration device as described in any one of claims 1 to 3, wherein the control unit outputs a drive signal in which at least one of the waveform of the drive signal that vibrates the piezoelectric element located at a position overlapping with the operation position, the intensity of the drive signal, and the frequency of the drive signal are determined based on the resonant frequency of the piezoelectric element located at a position overlapping with the operation position.

5. A vibration device as described in any one of claims 1 to 4, wherein the plurality of piezoelectric elements include a plurality of piezoelectric elements having a first resonant frequency and a plurality of piezoelectric elements having a second resonant frequency different from the first resonant frequency.

6. The vibration device according to claim 1 , wherein the plurality of piezoelectric elements includes at least three piezoelectric elements each having a different resonant frequency.

7. the control unit determines, among the plurality of piezoelectric elements, a piezoelectric element that is arranged at a first position that overlaps with the operation position, a plurality of piezoelectric elements that are arranged at a plurality of second positions that do not overlap with the operation position, and a piezoelectric element that is arranged at a third position that does not overlap with the operation position and is different from the first position and the plurality of second positions; A vibration device as described in any one of claims 1 to 6, wherein a piezoelectric element corresponding to the third position is not vibrated while a piezoelectric element corresponding to the first position and a piezoelectric element corresponding to the plurality of second positions are vibrated.

8. A vibration device as described in any one of claims 1 to 7, wherein the multiple piezoelectric elements are arranged in a matrix such that, when viewed from a direction perpendicular to the operating surface, piezoelectric elements having the same resonant frequency are adjacent to each other in the row direction and piezoelectric elements having different resonant frequencies are adjacent to each other in the column direction.

9. A vibration device as described in any one of claims 1 to 7, wherein the multiple piezoelectric elements are arranged in a matrix so that piezoelectric elements having different resonant frequencies are adjacent to each other in the row and column directions when viewed from a direction perpendicular to the operation surface.

10. The vibration device according to claim 1 , wherein the piezoelectric elements are spaced apart from one another.

11. a plurality of vibration plates each provided with a corresponding one of the plurality of piezoelectric elements; The piezoelectric element and the vibration plate are disposed in a housing that is disposed between the housing and the operation unit to form a housing space for housing the piezoelectric element and the vibration plate. Each of the plurality of diaphragms includes a main surface supported by the housing, The vibration device according to claim 1 , wherein a portion of the main surface is spaced apart from the housing.

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