JP2003047094A - Battery-driven apparatus/tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery-driven apparatus/tool added with a novel function utilizing a sounding material. SOLUTION: When a wristwatch 100 is shaken strongly, the shaking is sensed with an acceleration sensor 110, and a data taking section 112 is notified of this. At this time, the section 112 takes in time data from a timer section 114, and outputs the data to a sound synthetic section 115. The section 115 generates a sound signal corresponding to the inputted time data, and supplies it to a piezoelectric speaker 102. As the result, the speaker 102 outputs a sound of the present time, like an example 'It's ○ o'clock ×× minute in the afternoon'. Since a stacked type piezoelectric element is used, low driving voltage may be used.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to various battery-powered devices and equipment, and more particularly to an improvement of equipment and equipment suitable for a low driving voltage. 2. Description of the Related Art Piezoelectric drivers are widely used as simple electro-acoustic transducers and actuators. Especially recently,
It is expected to be applied to mobile phones and portable information terminals. Basically, the piezoelectric driving body has a unimorph structure whose cross section is shown in FIG. 7A and a bimorph structure whose cross section is shown in FIG. First, a piezoelectric driver having a unimorph structure has a configuration in which a piezoelectric element 900 is bonded to a shim plate 910. The piezoelectric element 900 includes an electrode 904 on the surface of a piezoelectric layer 902 made of a piezoelectric ceramic {a ceramic mainly composed of lead zirconate titanate (PZT for short), barium titanate, lead zirconate, lead titanate, or the like}. 906 is formed. A predetermined polarization is applied to the piezoelectric layer 902 by applying a voltage using the electrodes 904 and 906. On the other hand, the shim plate 910 is made of metal or the like. The piezoelectric element 900 is joined to the shim plate 910 by, for example, an adhesive. A driving signal is applied between the electrode 904 and the electrode 906 (or the shim plate 910) of the piezoelectric element 900 thus obtained, that is, on the front and back surfaces of the piezoelectric layer 902. Note that the shim plate 910 side is usually a common terminal. Then, the piezoelectric element 900 expands and contracts in the direction indicated by the arrow FA. However, the presence of the shim plate 910 causes the entire body to be curved, and as a result, is driven in the direction indicated by the arrow FB. [0004] On the other hand, a piezoelectric driver having a bimorph structure shown in FIG. 7B has a structure in which a piezoelectric element 920 is provided on the back side of a shim plate 910 shown in FIG. Piezoelectric element 92
No. 0 has a laminated structure in which electrodes 924 and 926 are formed on the surface of the piezoelectric layer 922. For the piezoelectric layer 922,
A predetermined voltage is applied using the electrodes 924 and 926, and a predetermined polarization is performed. The electrode 926 has the same potential as the electrode 906 and is usually grounded. In the case of this bimorph structure, the piezoelectric element 90
Since the polarization directions of the piezoelectric layers 902 and 922 of the 0 and the piezoelectric element 920 are opposite to each other, the expansion and contraction indicated by the arrows FA and FC are opposite to each other. That is, when the piezoelectric element 900 expands in the direction of the arrow FA, the piezoelectric element 920 contracts in the direction of the arrow FC. Conversely, when the piezoelectric element 900 contracts in the direction of the arrow FA, the piezoelectric element 920 expands in the direction of the arrow FC. That is, when one surface of the shim plate 910 is contracted, the other surface is extended, and the shim plate 910 is driven in the direction of arrow FB as a whole. [0006] By the way, since various portable devices and appliances are powered by batteries, the driving voltage is not always high. Therefore, even if a sounding body is provided, the lower the driving voltage, the better. Further, from the viewpoint of being portable, the sounding body is preferably thin. Conversely, a sounding body that satisfies such conditions can be attached to various devices, and can be used in various ways. The present invention has been made in view of the above points, and it is an object of the present invention to provide various battery-powered devices / appliances to which a novel function utilizing a sounding body is added. In order to achieve the above object, the present invention provides a piezoelectric speaker using a piezoelectric element in which a plurality of piezoelectric layers and electrode layers are alternately laminated; a sound output from the piezoelectric speaker Voice signal generating means for generating the signal data of the above. The above and other objects, features, and advantages of the present invention will be apparent from the following detailed description and the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 First, FIG.
Embodiment 1 of the present invention will be described with reference to FIG. In this embodiment, as shown in FIGS. 1A and 1B, the present invention is applied to a wristwatch. Figure (A)
Is an example of a piezoelectric speaker 10 housed in a wristwatch 100.
2 can be pulled out and used. In the example shown in FIG. 2B, the piezoelectric speaker 102 is provided on the side of the wristwatch 100. The piezoelectric speaker 102 uses a piezoelectric driver having a laminated structure as shown in FIG. First, FIG. 1A shows an example of a unimorph structure, in which a piezoelectric element 10 is bonded to a shim plate 20. Piezoelectric element 10
Has a structure in which piezoelectric layers 12A to 12C made of PZT or the like and electrode layers 14A to 14D are alternately laminated. These piezoelectric layers 12A to 12C and electrode layers 14A to 14D
After a predetermined number of laminations, the whole is fired at the same time, and then bonded to the approximate center of the shim plate 20 with an adhesive. Further, a voltage for polarization is applied to the piezoelectric layers 12A to 12C using the electrode layers 14A to 14D, and predetermined polarization is performed. The polarization is applied in opposite directions between adjacent piezoelectric layers. For example, if the piezoelectric layers 12A and 12C are polarized in the direction of the arrow F1, the piezoelectric layer 12B is polarized in the direction of the arrow F2 opposite to the arrow F1. For example, the electrode layers 14A, 1
When a voltage is applied such that 4C is negative and the electrode layers 14B and 14D are positive, polarization is performed in the directions of the arrows F1 and F2. On the other hand, the shim plate 20 is made of metal or the like. The piezoelectric element 10 is joined to the shim plate 20 by, for example, an adhesive. The periphery of the shim plate 20 is fixed and supported by appropriate means. A driving voltage such as an audio signal is applied between the electrode layers 14B and 14D and the electrode layers 14A and 14C, for example. Then, the piezoelectric layers 12 </ b> A to 12 </ b> C expand and contract simultaneously in the arrow FA direction because the voltage direction and the polarization direction match. However, due to the presence of the shim plate 20, the whole is curved, and as a result, it is driven in the direction indicated by the arrow FB. In this case, comparing the thickness of the piezoelectric layer with the above-described background art, the present embodiment is thinner,
In addition, since it has a laminated structure, it can be driven with a low driving voltage. FIG. 2B shows an example of a bimorph-type piezoelectric driver, in which a piezoelectric element 10 is provided on one surface of a shim plate 20 and a piezoelectric element 30 is provided on the other surface. . The piezoelectric element 30 includes the piezoelectric layers 32A to 32C and the electrode layer 3
4A to 34D are alternately laminated, and are joined to the shim plate 20 by an adhesive. Piezoelectric layer 32A
The polarization directions of to 32C are opposite to those of the piezoelectric layers 12A to 12C. A driving voltage such as an audio signal is applied to the electrode layer 14.
B, 14D, 34B, 34D and other electrode layers 14A, 1
4C, 34A, and 34C. For this reason,
The expansion and contraction of the piezoelectric element 10 in the direction of arrow FA and the expansion and contraction of the piezoelectric element 30 in the direction of arrow FC are opposite to each other. That is, when the piezoelectric element 10 extends in the direction of the arrow FA, the piezoelectric element 30
Contracts in the direction of arrow FC. Conversely, the piezoelectric element 10 has an arrow FA
When contracted in the direction, the piezoelectric element 30 extends in the direction of arrow FC. For this reason, it vibrates in the direction of arrow FB as a whole. Next, returning to FIG. 1, FIG. 1C shows a driving device of the piezoelectric speaker 102. As shown in the figure, an acceleration sensor 110 is provided inside the wristwatch 100, and its detection output side is connected to a data acquisition unit 112. The data acquisition unit 112 is connected to a clock unit 114 which is a function as an original clock.
The output side of the data acquisition unit 112 is connected to a voice synthesis unit 115, and the synthesized voice output side of the voice synthesis unit 115 is connected to the piezoelectric speaker 102. Electric power is supplied from a power supply 116 to each of the above units. A known circuit such as an amplifier for signal amplification is connected as necessary (the same applies to the following embodiments). Next, the operation of this embodiment will be described. When the user of the wristwatch 100 needs a time signal by voice, the wristwatch 100 is shaken strongly. Then, this is detected by the acceleration sensor 110, and the fact is notified to the data capturing unit 112. At this time, the data capturing unit 112 captures the time data from the clock unit 114 and outputs the time data to the voice synthesizing unit 115. The voice synthesizer 115 generates a voice signal corresponding to the input time data, and supplies the generated voice signal to the piezoelectric speaker 102. Then, the sound of the current time is output from the piezoelectric speaker 102, for example, "It is xx hours x pm". This is convenient when the watch 100 is hidden and cannot be seen. According to the present embodiment, a laminated piezoelectric element is used as the piezoelectric speaker 102.
Therefore, as described above, the driving voltage of the piezoelectric speaker 102 may be low. Accordingly, even if the driving voltage of the power supply 116 is low, it can cope with the driving voltage and does not require a booster circuit. Also,
A large sound pressure can be obtained because of the stacked type. This embodiment can be applied to a calculator 120 and the like as shown in FIG. The example shown in the figure is a type driven by a solar battery 122, and a piezoelectric speaker 124 is provided on the operation / display panel side. When the user operates the key group 126 to perform an appropriate calculation input and finally presses the equal key 128, the calculation result is displayed on the piezoelectric speaker 124.
Is output as voice. <Second Embodiment> Next, a second embodiment will be described with reference to FIG. This embodiment is an embodiment for preventing a lost item or theft, and is constituted by a transmitting card 200 and a receiving card 210 as shown in FIG. The transmission card 200 includes a transmission unit 202 and an antenna 204 as shown in FIG. The receiving card 210 includes an antenna 212, a receiving unit 214, a receiving level detecting unit 216, and a piezoelectric speaker 218, as shown in FIG. The transmission card 200 is stored in, for example, a user's bag or outerwear. On the other hand, the receiving card 210
Is attached to an object to be prevented from being left behind or stolen, for example, a wallet, a commuter pass, a card holder such as a license or a credit card, a clock, a mobile phone, and the like. Calling card 200
Outputs a constant signal from the transmitting unit 202, which is transmitted from the antenna 204. This radio wave is received by receiving card 2
The signals are received by the ten antennas 212 and the receiving unit 214. Then, the reception signal level is detected by the reception level detection section 216. As a result, when the reception level is lower than a certain level, a detection signal to that effect is output to the piezoelectric speaker 218, and the piezoelectric speaker 218 emits sound. The received signal level is generally considered to be inversely proportional to the distance between the transmitting card 200 and the receiving card 210, though it depends on the situation. That is, both cards 200,
The further the distance 210 is, the lower the received signal level becomes, and the piezoelectric speaker 218 emits sound. For this reason, the user can know from this sound that the user has forgotten or stolen a portable item such as a wallet. According to the present embodiment, since the piezoelectric speaker is used, the receiving card 210 can be made thin and the driving voltage of the receiving card 210 can be kept low. FIG. 4 shows a specific example. First, FIG. 4A shows an example in which the receiving card 210 is stored in the wallet 220. When the wallet 220 is dropped or stolen and the distance from the calling card 200 increases, the receiving card 210 sounds. FIG. 7B shows an example in which the reception card 210 is carried by the child 230. The reception card 210 sounds when the child 230 gets out of the crowd at a department store or an amusement park, so that the child 230 can easily find it. FIG. 3C shows that the reception card 21
FIG. 2D is an example in which the function of the receiving card 210 is built in the key holder 250. In each case, the key 240 or the key 252 attached to the key holder 250 can be prevented from being lost or stolen. <Third Embodiment> Next, a third embodiment will be described with reference to FIG. This example is an example in which a piezoelectric speaker 302 is attached to a business card 300 as shown in FIG. The business card 300 includes a flash memory 304, a data acquisition unit 306, a DAC, as shown in FIG.
(Digital-analog converter) 308, diode 31
0 is built in, and a diode 310 is connected to the piezoelectric speaker 302. The recording terminal 305 of the flash memory 304 is exposed from the business card 300. When using the business card 300, first, a desired audio signal is digitally recorded in the flash memory 304 using the recording terminal 305 using an appropriate signal recording adapter. In use, the piezoelectric speaker 3
Press 02. Since the piezoelectric speaker 302 uses a piezoelectric material as described above, it outputs a signal when pressed. This signal is supplied to the data acquisition unit 306 by the diode 310. Then, the data capturing unit 30
The audio signal recorded in the flash memory 304 is captured by 6, converted into an analog signal by the DAC 308, and supplied to the piezoelectric speaker 302. As a result, sound corresponding to the sound signal is output from the piezoelectric speaker 302. For example, as shown in FIG. 5C, "I am a newcomer. Thank you." Of course, if a plurality of audio signals are stored in the flash memory 304 and data is captured in correspondence with the number of times the piezoelectric speaker 302 is pressed, the audio can be changed according to the situation. Become.
According to the present embodiment, a novel function that a business card speaks can be given, and a unique and strong impression can be given. <Fourth Embodiment> Next, a fourth embodiment will be described with reference to FIG. In this example, as shown in FIG. 1A, a piezoelectric speaker 402 is attached to a remote control such as a television or an air conditioner, or a keyless remote control 400 for an automobile. The remote controller 400 is provided with an audio signal data memory 404 storing audio signal data, a data reading unit 406, and a DAC 408, as shown in FIG. When any of the buttons 410 of the remote controller 400 is operated, the operation button information is input to the data reading unit 406. Then, the data reading unit 406 stores the audio signal data corresponding to the operation button in the audio signal data memory 4.
Read from 04. The read audio signal is the DAC4
08, the digital signal is converted into an analog signal and supplied to the piezoelectric speaker 402. As a result, sound corresponding to the sound signal is output from the piezoelectric speaker 402. For example, when the channel is switched from "1" to "3" with the remote controller of the television, the sound "switch the channel to 3" is output. By doing so, voice guidance corresponding to the button operation can be performed. The voice guidance may be provided based on a reception confirmation signal from the other party. For example, when the button of channel "3" is operated on the remote controller of the television, the channel is switched to "3" based on this, and the reception confirmation signal is sent from the television to the remote controller. This reception confirmation signal is
At the time of reception at 00, the data is read out, and voice guidance of “channel has been switched to 3” is given. By doing so, the user can confirm at hand that the other party has received the operation signal, and the remote control operation can be reliably performed. <Other Embodiments> The present invention is not limited to the above embodiments, and can be applied to various portable and portable devices and appliances driven by batteries. As described above, according to the present invention,
The use of a piezoelectric speaker using a piezoelectric element with a laminated structure allows the sounding body to be driven satisfactorily even in battery-powered equipment and appliances, and the novel function can be added. There is.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a first embodiment of the present invention. FIG. 2 is a main cross-sectional view showing a laminated structure of the piezoelectric driver according to the embodiment. FIG. 3 is a diagram showing a second embodiment of the present invention. FIG. 4 is a diagram showing an application example of the second embodiment. FIG. 5 is a diagram showing a third embodiment of the present invention. FIG. 6 is a diagram showing a fourth embodiment of the present invention. FIG. 7 is a diagram showing a structure of a conventional piezoelectric driving body. DESCRIPTION OF SYMBOLS 10 Piezoelectric elements 12A to 12C Piezoelectric layers 14A to 14D Electrode layer 20 Shim plate 30 Piezoelectric elements 32A to 32C Piezoelectric layers 34A to 34D Electrode layer 100 Wristwatch 102 Piezoelectric speaker 110 Acceleration sensor 112 Data acquisition unit 114 Clock unit 115 Voice synthesis unit 116 Power supply 120 Calculator 122 Solar cell 124 Piezoelectric speaker 126 Key group 128 Equal key 200 Transmission card 202 Transmission unit 204 Antenna 210 receiving card 212 antenna 214 receiving unit 216 receiving level detecting unit 218 piezoelectric speaker 220 wallet 230 child 240 key 250 key holder 252 key 300 business card 302 piezoelectric speaker 304 flash memory 305 recording Terminal 306 data acquisition unit 308 DAC 310 Eau 400 ... keyless remote control 402 ... piezoelectric speaker 404 ... audio signal data memory 406 ... data reading part 408 ... DAC 410 ... button

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Hiroaki Uenishi             6-16-20 Ueno, Taito-ku, Tokyo Taiyo Invitation             Denden Co., Ltd. F term (reference) 5D004 AA01 AA09 DD01                 5D107 BB08 CC03 DD03 FF03

Claims (1)

Claims: 1. A piezoelectric speaker using a piezoelectric element in which a plurality of piezoelectric layers and electrode layers are alternately stacked; an audio signal generating means for generating audio signal data output from the piezoelectric speaker A battery-operated device or device comprising: