179 results about "Piezoelectric speaker" patented technology

There are provided microphones <HIL><PDAT>11</BOLD><PDAT>A, <HIL><PDAT>11</BOLD><PDAT>B arranged at least any two different locations of edge portions of a touch panel <HIL><PDAT>10, </BOLD><PDAT>for sensing a ultrasonic signal propagated through a space, an input pen <HIL><PDAT>12 </BOLD><PDAT>containing a piezoelectric loudspeaker <HIL><PDAT>12</BOLD><PDAT>G, for oscillating a ultrasonic wave that is output from the piezoelectric loudspeaker <HIL><PDAT>12</BOLD><PDAT>G, and a touch position sensor <HIL><PDAT>13 </BOLD><PDAT>for calculating a coordinate of a touch position P by calculating distances between the microphones <HIL><PDAT>11</BOLD><PDAT>A, <HIL><PDAT>11</BOLD><PDAT>B and the touch position P of the input pen <HIL><PDAT>12 </BOLD><PDAT>on the touch panel <HIL><PDAT>10 </BOLD><PDAT>based on the ultrasonic wave sensed by the microphones <HIL><PDAT>11</BOLD><PDAT>A, <HIL><PDAT>11</BOLD><PDAT>B, whereby the microphones <HIL><PDAT>11</BOLD><PDAT>A, <HIL><PDAT>11</BOLD><PDAT>B have a sound collecting directivity characteristic in response to fitted positions of the edge portions of the touch panel <HIL><PDAT>10. </BOLD></PTEXT>

According to an aspect, a sound outputting device includes a front unit, a first side unit, a second side unit, a sound transmitting portion, and a piezoelectric speaker. The first side unit is coupled to one end portion of the front unit. The second side unit is coupled to another end portion of the front unit. The sound transmitting portion is provided in the first side unit for transmitting a sound via cartilage conduction. The piezoelectric speaker vibrates the sound transmitting portion.

There is provided a capacitive load driving circuit which applies a driving signal to a capacitive load. The driving circuit includes: an operational amplifier outputting a difference signal between signals from an inverting input terminal and a non-inverting input terminal, and setting a loop gain; a pulse width modulator pulse-width-modulating the difference signal outputted by the operational amplifier, and outputting resultant digital signal; a digital voltage amplifier amplifying a voltage of the digital signal; a first filter smoothing a digital signal from the digital voltage amplifier, and supplying a smoothed signal to the capacitive load as the driving signal; an impedance converting circuit converting an impedance of an output signal of the first filter; and a first feedback circuit feeding-back the driving signal, which is outputted from the first filter, to the inverting input terminal of the operational amplifier via the impedance converting circuit.

A piezoelectric speaker that includes an electrode formed on opposing main surfaces of a piezoelectric sheet having a predetermined stretching axis and made of a chiral polymer. The electrode is divided into four electrode portions by a plurality of dividing lines extending in a radiation direction. The four electrode portions are distributed along the outer peripheral portion except for the central portion of a vibration region. Voltage is applied to the respective four electrode portions in such a manner that electric field vectors generated in the thickness direction of the piezoelectric sheet direct in opposite directions between the adjacent ones of four sheet portions of the piezoelectric sheet to which voltage is applied by the electrode portions.

A piezoelectric device is provided with a sound source IC, an amplifier for amplifying a sound source from the sound source IC, a piezoelectric speaker for generating sound based on a drive signal from amplifier, an MPU for performing a predetermined control process on the drive signal, a memory for storing temperature dependency information about the piezoelectric constant (d₁₄) and Young's modulus E of the piezoelectric speaker, and a temperature sensor for detecting an ambient temperature. MPU has correcting unit, compares a detected result of the temperature sensor with the temperature dependency information, and performs temperature correction on the drive signal serving as an acoustic signal based on a compared result. The piezoelectric speaker outputs the acoustic signal temperature-corrected by correcting unit. Thus, it becomes possible to realize various piezoelectric devices, such as a piezoelectric speaker system, capable of preventing various input information from fluctuating even when there is a change in usage environmental temperature.

A piezoelectric speaker is a piezoelectric speaker which radiates acoustic waves by vibrating according to an applied voltage, including (i) a substrate which includes a first region having first bending stiffness against bending of a plane perpendicular to a vibration direction and a second region having second bending stiffness against bending of the perpendicular plane, the second bending stiffness being different from the first bending stiffness, (ii) a first piezoelectric element which is mounted on the first region and to which a voltage of a first frequency band is applied, and (iii) a second piezoelectric element which is mounted on the second region and to which a voltage of a second frequency band different from the first frequency band is applied.

It is designed to restrain vibration of a casing, efficiently drive a piezoelectric sounding body (such as a piezoelectric speaker) and flatten sound pressure characteristic within the electronic instrument requiring the miniaturized type, light weight, and thin type in the electronic instrument, in particular the portable telephone. For accomplishing these objects, at a back side of a mass part within the casing of the electronic instrument, the piezoelectric sounding body is mounted via a ring shaped cushioning material. At a part not overlapping with the mass part, a partition is provided. A main air-chamber is tightly formed by the mass part, the piezoelectric sounding body, and the partition, and in the casing within the main air-chamber, a sound issuing hole is formed. The sound outputted from the upper face into the main air-chamber is outputted outside of the casing from the sound issuing hole. Vibration generated from the piezoelectric sounding body interferes with the mass part, so that transmission of vibration to the casing is restrained, and since the space of the inside and outside of the piezoelectric sounding body is served as the air-chamber, the sound pressure characteristic is made flat.

A thin film circuit substrate is provided with a voice-output-section driving section, formed of a thin film layer on an insulative substrate, for driving a voice output section. An antisurge section, provided on a wiring between the voice-output-section driving section and an output terminal section thereof, includes an antisurge element. When a surge voltage is applied to the wiring, the antisurge element, monolithically formed on the thin film circuit substrate, connects the wiring to the ground so as to pass a current (surge current), generated by the surge voltage applied to the wiring, to the ground. This makes it possible to provide a thin film circuit substrate which is monolithically provided with a function which can protect a circuit section when a voltage exceeding a predetermined range is applied to the wiring linking the circuit section with an input terminal section or an output terminal section.

A piezoelectric speaker and a method of manufacturing the same that can obtain a high sound pressure using a piezoelectric thin film are provided. The piezoelectric speaker includes a piezoelectric thin film, electrodes formed on an upper surface or upper and lower surfaces of the piezoelectric thin film, a damping material layer formed on the lower surface of the piezoelectric thin film, and a frame attached around at least one of the piezoelectric thin film and the damping material layer using an adhesive.

The present invention relates to a piezoelectric speaker comprising a membrane, and an actuating layer comprising at least one piezoelectric element mounted to the membrane, which at least one piezoelectric element is adapted to, when actuated, cause the membrane to vibrate in order to generate sound. The speaker is characterized by means for varying the fraction of the actuating layer that is actuated depending on the sound frequency to be generated, wherein a smaller fraction of the actuating layer is actuated for higher sound frequencies. Varying the fraction of the actuating layer that is actuated depending on the sound frequency to be generated allows reduction of the power consumption of the speaker with maintained sound pressure level. The invention also relates to a method for driving a piezoelectric speaker.

An input pen has an oscillator and a piezoelectric loudspeaker, a frequency/output-level setting circuit for setting a frequency or an output level of a ultrasonic wave oscillated from the oscillator, and a touch sensor for changing a set value of the frequency/output-level setting circuit. A touch panel device comprises microphones for sensing the frequency or the output level of the ultrasonic wave oscillated from the oscillator of the input pen at a touch position on a touch panel by the input pen; a microcomputer for setting attributes of input information in response to the frequency or the output level of the ultrasonic wave sensed by the microphones; and a PDP displaying device for displaying the input information on the flat display device based on the set attributes.

In a piezoelectric speaker, an acoustic diaphragm is thicker than a piezoelectric thin film and is formed of a more flexible and higher elasticity material than the piezoelectric thin film, thereby greatly improving output sound pressure in a low frequency band and reducing sound distortion. Further, the piezoelectric thin film is attached to the acoustic diaphragm in an inclined structure in which the piezoelectric thin film is horizontally turned from the acoustic diaphragm, thereby preventing a standing wave from being created by structural symmetry and minimizing sound distortion.

The invention discloses a piezoelectric speaker based on a piezoelectric cantilever beam, belonging to the technical filed of piezoelectricity. The piezoelectric speaker is structured by bonding an upper layer piezoelectric ceramic piece and a lower layer piezoelectric ceramic piece of opposite polarization directions at both sides of a middle layer fiber sheet, thereby forming a piezoelectric cantilever beam; one end of the piezoelectric cantilever beam is fixed with an external frame so as to form a fixed end from which electrodes are led out; the movable end of the piezoelectric cantilever beam is connected with a vibration sheet by a link block with a damp function; and the vibration sheet is bonded to the external frame through a vibration film. The vibration sheet can serve as the main medium for driving air around the speaker and also the counter weight of the speaker, can reduce the first-order resonance frequency of the speaker effectively, and improve the effect of low pitch replay. The piezoelectric speaker provided by the invention has the characteristics of low resonance frequency, simple vibration mode and large vibration range and the like, and has the advantages of good low pitch performance, stable sound pressure output and high sound output and the like compared with a conventional surface mount type piezoelectric speaker.

The present invention detects whether the supply voltage applied to the power supply terminal (3) is used for the dynamic speaker or for the piezoelectric speaker by the power supply voltage detection circuit (10), switches the gain of the amplifier circuit (8) in accordance with the detection result by the gain switching circuit (11) so that the same output power is produced for the same input signal in the respective speaker driving, and amplifies the input signal from the input terminal (5) by the amplifier circuit (8) having the gain to drive a speaker (1) that is connected to the output terminals (6, 7).

A driver circuit for a piezoelectric speaker is described, wherein charge is transferred from a charge reservoir to the speaker. In a first embodiment a delta sigma circuit uses a pulse width modulated digital audio signal to control a push-pull circuit to drive the piezoelectric speaker. High frequency harmonics are introduced to the delta sigma drive signals to enhance the low frequency response of the speaker. A charge recovery mechanism recovers charge from the speaker to reduce the frequency of replenishing the charge reservoir and to provide additional drive current for the speaker. In a second embodiment the pulse width modulated signal is used to drive a voltage quadrupling circuit that drives the piezoelectric speaker, wherein the reservoir capacitor is integrated with the capacitors of quadrupling circuit, which provides charge recovery.

The invention discloses a combined coaxial full-frequency loudspeaker in a double-transduction mode, which includes a magnetic circuit structure, a voice coil is provided on the upper part of the magnetic circuit structure, and a vibration plate is provided at the output end of the voice coil, and the vibration plate is A disc made of piezoelectric material is used, and the disc is fixed on the magnetic circuit structure through a ring and a washer. The present invention combines the dynamic speaker and the piezoelectric speaker, and uses the transducer device of the piezoelectric speaker - the piezoelectric disc as the vibrating plate (cone) of the dynamic speaker to work in the low frequency band as an electrodynamic transducer. Working with piezoelectric transducers in the high-frequency band, a new type of unique combined full-range speaker is formed. Full frequency band work. The invention can be widely used in the field of loudspeakers.

The invention belongs to the technical field of speakers, particularly relating to a thin piezoelectric speaker with a novel diaphragm structure. The structure of the speaker comprises a diaphragm, a piezoelectric ceramic wafer, an electrode, an electrode leading wire and a edge frame, wherein the piezoelectric ceramic wafer is adhered on the diaphragm; the electrode is arranged on the surface ofthe piezoelectric ceramic wafer; the electrode leading wire is connected with the electrode and an outer circuit; and the edge frame is used for restricting the diaphragm. The characteristics of the medium and low frequency section of the piezoelectric speaker are regulated through introducing single holes, single hole arrays, multiple holes, multiple hole arrays and porous symmetrical structureson the rectangular or round diaphragm, thus the distortion rate is reduced; the phase cancellation of medium-frequency range sound irradiation in space is lowered or eliminated; the evenness of the acoustic pressure level frequency response curve of the piezoelectric speaker is greatly improved; even if the acoustic pressure level at the distortion position is improved by above 25db, which is generated by the fact that the voltage applied on the frequency bandwidth of the distortion position is improved by 17 times, so that the sound quality of the piezoelectric speaker is better; and in addition, the rigidity and quality distribution of the diaphragm are improved, thus the output of the acoustic pressure of the speaker at the medium frequency range is obviously increased.

The present invention intends to provide a piezo-electric speaker which can generate a sound from the low frequency range to the high frequency range as well as transmit the acoustic vibration to a sound-board with a high efficiency. This is achieved by providing a piezo-electric speaker comprising a piezo-electric member generating a strain according to an electric signal applied thereto; a piezo-electric vibration plate converting the strain to the acoustic vibration; and a sound-board resonating to the acoustic vibration; the piezo-electric plate being supported on the sound-board; the acoustic vibration caused by the piezo-electric vibration plate being propagated from the sound-board to the ambient air to generate a sound.

An electroacoustic transducer has a housing, piezoelectric speaker, dynamic speaker, and support member. The piezoelectric speaker includes a vibration plate having a first surface and a second surface on the opposite side of the first surface, as well as a piezoelectric element joined to at least one of the first surface and second surface, and divides the interior of the housing into a first space facing the first surface and a second space facing the second surface. The dynamic speaker is placed in the first space. The support member is constituted by a part of the housing or by a member different from the housing, has a supporting part facing the first surface or second surface, and supports the periphery of the first surface or second surface with the supporting part.

Methods and apparatus for improving the acoustical performance associated with a speaker, such as a piezoelectric speaker, are disclosed. According to one aspect, an apparatus includes a substrate, a can mounted on the substrate, and a piezoelectric speaker arrangement. The piezoelectric speaker arrangement is at least partially mounted on the can. In one embodiment, the substrate is a printed circuit board (PCB) and the can is an electromagnetic interference (EMI) shielding can.