Vibration device and vibration method thereof

Abstract

The invention relates to a vibration device and a vibration method thereof. In the IC card, a control circuit includes a microcomputer for generating a square pulse-shaped drive signal and a transistor for boosting the square pulse-shaped drive signal generated by the microcomputer, and uses the drive signal boosted by the transistor as a drive signal for driving a piezoelectric element. The drive signal generated by the transistor is boosted than the drive signal generated by the microcomputer, whereby the intensity of the vibration of the piezoelectric element can be improved.

Description

Technical Field

[0001] The present invention relates to a vibration device and a vibration method thereof. Background Art

[0002] In Japanese Unexamined Patent Application Publication No. 2014-132404, as a type of vibration device, a non-contact IC card having a vibration mechanism is disclosed, and a piezoelectric element or a vibration motor is used as a vibration source of the vibration mechanism. Summary of the Invention

[0003] The inventors repeatedly studied the intensity of vibration of the vibration device, and as a result, newly discovered a technique capable of increasing the intensity of vibration.

[0004] According to various aspects of the present invention, there are provided a vibration device and a vibration method thereof, which achieve an increase in the intensity of vibration.

[0005] The vibration device according to one aspect of the present invention includes: a power receiving unit that receives non-contact power supply from a power supply device; a control unit that generates a drive signal by using the power received by the power receiving unit; and a piezoelectric vibrator that vibrates according to the drive signal generated by the control unit. The control unit includes: a first control unit that generates a square pulse signal; and a second control unit that boosts the square pulse signal generated by the first control unit to generate a drive signal.

[0006] The vibration method of the vibration device according to one aspect of the present invention is such that the vibration device includes a power receiving unit that receives non-contact power supply from a power supply device, a control unit that generates a drive signal by using the power received by the power receiving unit, and a piezoelectric vibrator. The control unit includes a first control unit that generates a square pulse signal and a second control unit that boosts the square pulse signal generated by the first control unit to generate a drive signal. In the vibration device, the piezoelectric vibrator vibrates according to the drive signal generated by the control unit.

[0007] In the above vibration device and vibration method, the control unit includes a first control unit that generates a square pulse signal and a second control unit that boosts the square pulse signal generated by the first control unit. By using the signal boosted by the second control unit as the drive signal for driving the piezoelectric vibrator, the intensity of vibration can be increased. Brief Description of the Drawings

[0008] Figure 1 is a schematic perspective view showing an IC card according to an embodiment.

[0009] Figure 2 is a view showing Figure 1 the state where the IC card shown is placed on a reader / writer.

[0010] Figure 3 is a view showing Figure 1Exploded perspective view of the stacked structure of the IC card shown.

[0011] Figure 4 It shows Figure 1 A diagram of the vibration circuit of the IC card shown.

[0012] Figure 5 A diagram showing the operation when the power supply to the IC card is appropriate.

[0013] Figure 6 A diagram showing the operation when the power supply to the IC card is weak.

[0014] Figure 7 A diagram showing the operation when the power supply to the IC card is insufficient. Detailed implementation manners

[0015] Hereinafter, various implementation manners and embodiments will be described with reference to the accompanying drawings. In addition, the same or corresponding parts are denoted by the same reference numerals in the respective drawings, and redundant descriptions are omitted.

[0016] As one kind of vibration device, taking Figure 1 the IC card 1 shown as an example for explanation. The IC card 1 incorporates an IC module 10 for performing arithmetic processing. The IC card 1 of this embodiment is non-contact type and incorporates the antenna coil 16 described below. As Figure 2 shown, the IC module 10 is placed over a reader / writer 2 which is a kind of power supply device (i.e., maintained in a state of being separated by a specified distance), receives non-contact power supply from the reader / writer 2, and communicates with the reader / writer 2. "Non-contact power supply" in this specification includes not only power transmission but also non-contact communication such as near field communication (NFC).

[0017] The IC card 1 has a plate-like outer shape with a front surface 1a and a back surface 1b. The IC module 10 is exposed on the front surface 1a. The IC card 1 has Figure 3 the stacked structure shown, and is stacked in the order of a plastic plate 11, an antenna sheet 12, a base material 13, and a metal plate 14 from the back surface 1b side. The layers of the IC card 1 are bonded by a known bonding layer (e.g., double-sided adhesive tape, adhesive material layer) not shown.

[0018] The plastic plate 11 is made of a resin material that does not obstruct magnetic flux. The front surface of the plastic plate 11 constitutes the back surface 1b of the IC card 1. The metal plate 14 is made of a metal material such as stainless steel or titanium. The front surface of the metal plate 14 constitutes the front surface 1a of the IC card 1. The IC module 10 is embedded in a part of the area of the metal plate 14.

[0019] The base material 13 is a film made of an insulating resin material, for example, it can be made of acrylic. A voltage regulator 15, a piezoelectric element 18, and a control circuit 20 are mounted on the base material 13. The piezoelectric element 18 is a type of piezoelectric vibrator. The piezoelectric vibrator can be composed only of the piezoelectric element, or it can be a combination of the piezoelectric element and a vibration plate. The vibration plate can be a plate made of resin or a plate made of metal. In the present embodiment, the piezoelectric element 18 is housed in a through hole provided in the base material 13 and bonded to the back surface 14a of the metal plate 14. By bonding and fixing the piezoelectric element 18 to the metal plate 14, the displacement or vibration of the piezoelectric element 18 is transmitted to the metal plate 14. That is, the vibration generated in the piezoelectric element 18 is transmitted from the inside of the IC card 1 to the surface portion and is directly felt by the user of the IC card 1. The IC card 1 can vibrate as a whole or a part of the surface portion can vibrate locally.

[0020] The antenna sheet 12 is made of an insulating resin material or a magnetic material. An antenna coil 16 including a coil pattern wound along the outer edge is provided on the antenna sheet 12. The antenna coil 16 is electrically connected to the voltage regulator 15 of the base material 13. The antenna coil 16 is magnetically connected to the coil included in the IC module 10 of the metal plate 14.

[0021] The IC card 1 has a vibration circuit 30 having the structure shown in Figure 4 That is, the IC card 1 has a power receiving unit 17 that receives non-contact power supply from the reader / writer 2, a control circuit 20 (control unit) that generates a drive signal based on the power received by the power receiving unit 17, and a vibration circuit 30 configured to include a piezoelectric element 18 that vibrates based on the drive signal generated by the control circuit 20.

[0022] The power receiving unit 17 includes the above-mentioned voltage regulator 15 and antenna coil 16, receives non-contact power supply from the reader / writer 2, and outputs two drive voltages. The control circuit 20 includes a microcomputer 21 (first control unit) and a transistor 22 (more specifically, a field effect transistor (FET) or a bipolar transistor) (second control unit). Drive voltages are applied to the microcomputer 21 and the transistor 22 respectively from the power receiving unit 17. In the present embodiment, among the two drive voltages output from the power receiving unit 17, the drive voltage V1 (for example, +5V) applied to the microcomputer 21 is lower than the drive voltage applied to the transistor 22 (for example, +14V). The high-voltage drive voltage applied to the transistor 22 can be output from the diode bridge included in the power receiving unit 17. Through the square pulse-shaped drive signal V2 generated by the microcomputer 21, the transistor 22 performs a switching operation to generate a drive signal sent to the piezoelectric element 18. The piezoelectric element 18 vibrates with an element drive voltage V3 according to the square pulse-shaped drive signal sent from the control circuit 20.

[0023] Next, refer to Figure 5, the ideal drive voltage V1, drive signal V2, and element drive voltage V3 are described. Figure 5 It represents the operations of voltage, signal, and vibration. The horizontal axis represents the passage of time, and the vertical axis represents the amplitude. In addition, the ideal drive voltage V1, drive signal V2, and element drive voltage V3 are the states when the separation distance between the IC card 1 and the reader / writer 2 is sufficiently short (for example, in direct contact with a zero separation distance), and the power supply from the reader / writer 2 to the IC card 1 is properly conducted.

[0024] In Figure 5 this state, the drive voltage V1 applied from the power receiving unit 17 to the microcomputer 21 of the control circuit 20 always remains at a certain value (for example, +5V). At this time, in the microcomputer 21 of the control circuit 20, an ideal square-wave drive signal V2 is generated. Then, the piezoelectric element 18 vibrates with the element drive voltage V3 according to the drive signal from the control circuit 20. Specifically, the piezoelectric element 18 expands (or contracts) at the timing t1 when the drive signal V2 rises, and gradually starts to contract (or expand) at the timing t2 when the drive signal V2 falls, and vibrates by repeating such expansion and contraction. At this time, the period T (and the frequency 1 / T) of the piezoelectric element 18 is obtained based on the interval of the expansion timing t1 (or the interval of the start of contraction timing t2).

[0025] Next, Figure 6 It represents the operations of voltage, signal, and vibration when the distance between the IC card 1 and the reader / writer 2 is slightly farther (for example, the separation distance is 12 mm), and the power supply from the reader / writer 2 to the IC card 1 is weak. In Figure 6 this state, the drive voltage V1 applied from the power receiving unit 17 to the microcomputer 21 of the control circuit 20 is not always at a certain value, and is slightly lower compared to Figure 5 the state. Specifically, at the timing t1 when the piezoelectric element 18 expands, the drive voltage V1 decreases. In addition, the drive signal V2 of the control circuit 20 also has a voltage drop. Although the piezoelectric element 18 vibrates with the same period T as Figure 5 the state, the intensity of the vibration represented by the vertical axis is lower than that of Figure 5 the state.

[0026] Figure 7 It represents the operations of voltage, signal, and vibration when the distance between the IC card 1 and the reader / writer 2 is far (for example, the separation distance exceeds 18 mm), and the power supply from the reader / writer 2 to the IC card 1 is insufficient. In Figure 7 this state, the drive voltage V1 applied from the power receiving unit 17 to the microcomputer 21 of the control circuit 20 is not always at a certain value, and is compared to Figure 6is further reduced compared to the state. Specifically, at the timing t1 when the piezoelectric element 18 elongates, the drive voltage V1 decreases significantly. As a result, an insufficient drive voltage V1 is not applied to the microcomputer 21 of the control circuit 20, and the microcomputer 21 temporarily stops at the timing t1, and the microcomputer 21 resumes after the timing t2 when the drive voltage V1 recovers. The intensity of the vibration of the piezoelectric element 18 represented by the vertical axis is lower than that in the Figure 5 state. Due to power shortage and the subsequent stop of the microcomputer 21, the piezoelectric element 18 is different from Figure 5 , 6 state, the intensity of vibration weakens, and the period T extends (i.e., the frequency decreases).

[0027] In the IC card 1, the control circuit 20 includes a microcomputer 21 that generates a square pulse-shaped drive signal V2 and a transistor 22 that switches the square pulse-shaped drive signal V2 generated by the microcomputer 21. The drive voltage applied to the transistor 22 from the power receiving unit 17 can be output from the diode bridge included in the power receiving unit 17 and is a voltage higher than the drive signal V1 sent from the power receiving unit 17 to the microcomputer 21. By switching the transistor 22 with the square pulse-shaped drive signal V2 generated by the microcomputer 21, it is possible to drive the piezoelectric element 18 with an element drive voltage V3 higher than the drive signal V2 output from the microcomputer 21 (i.e., boosted) (V2 < V3), and it is possible to increase the intensity of the vibration of the piezoelectric element 18.

[0028] In addition, in the IC card 1, the vibration mode (first vibration mode) of the piezoelectric element 18 when the separation distance between the reader / writer 2 and the power receiving unit 17 is close (at the first distance) is different from the vibration mode (second vibration mode) of the piezoelectric element 18 when the separation distance is longer than the first distance (at the second distance). In the present embodiment, Figure 5 the first vibration mode of the piezoelectric element 18 when the separation distance is close as shown is different from Figure 7 the second vibration mode of the piezoelectric element 18 when the separation distance is far as shown, the intensity (amplitude) of the vibration is larger, and the period T is shorter. Therefore, the user can sense the difference in the distance between the IC card 1 and the reader / writer 2 based on the difference in the vibration mode (for example, whether it is the first distance or the second distance). That is, the user can obtain information related to the above separation distance, and the amount of information transmitted to the user is increased.

[0029] In addition, if the first vibration mode and the second vibration mode are different, it may not necessarily be a way in which both the amplitude and the period of the vibration are different, and it may also be a way in which only one of them is different.

[0030] The square pulse signal generated by the microcomputer 21 may be a signal with a uniform pulse width or a signal with a modulated pulse width (i.e., a PWM signal). By generating a PWM signal by the microcomputer 21, the vibration of the piezoelectric element 18 that vibrates according to the drive signal of the control circuit 20 is modulated, whereby a desired sound can be emitted from the piezoelectric element 18.

[0031] The present invention is not limited to the above-described embodiments and can be variously modified. For example, the first control unit is not limited to a microcomputer and may be an IC chip such as a timer IC. The second control unit is not limited to an FET and may be other transistors.

[0032] In addition, the vibration device is not limited to the card type and may be in the form of various small parts (fashion items, tools, accessories, etc.). The power supply device is not limited to a reader and may be a settlement terminal or the like.

Claims

1. A vibration device, wherein: have: a power receiving unit that receives contactless power from the power supply device; a control unit that generates a drive signal using the power received by the power receiving unit; and a piezoelectric vibrator that vibrates according to a drive signal generated by the control unit, The control unit includes a first control unit that generates a square pulse signal and a second control unit that generates the drive signal by boosting the square pulse signal generated by the first control unit.

2. The vibration device according to claim 1, wherein A first vibration mode of the piezoelectric vibrator when the power supply device and a power receiving unit are separated by a first distance differs from a second vibration mode of the piezoelectric vibrator when the separation distance is a second distance longer than the first distance.

3. The vibration device according to claim 2, wherein: The first vibration mode and the second vibration mode are different in at least one of amplitude and period.

4. The vibration device according to claim 3, wherein: The amplitude of the first vibration mode is greater than the amplitude of the second vibration mode.

5. The vibration device according to claim 3, wherein: A period of the first vibration pattern is shorter than a period of the second vibration pattern.

6. The vibration device according to any one of claims 1 to 5, wherein: The vibration device is an IC card.

7. The vibration device according to any one of claims 1 to 6, wherein: The square pulse signal generated by the first control unit is a PWM signal.

8. The vibration device according to any one of claims 1 to 7, wherein: The second control unit includes a transistor.

9. A vibration method for a vibration device, wherein: The vibration device comprises a power receiving unit that receives contactless power from a power supply device, a control unit that generates a drive signal using the power received by the power receiving unit, and a piezoelectric vibrator, wherein the control unit includes a first control unit that generates a square pulse signal, and a second control unit that generates the drive signal by boosting the square pulse signal generated by the first control unit. In the vibration device, the piezoelectric vibrator vibrates according to the drive signal generated by the control unit.

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