561results about "Electrostatic transducer loudspeakers" patented technology

The present invention relates to transducers, their use and fabrication. The transducers convert between mechanical and electrical energy. Some transducers of the present invention include a pre-strained polymer. The pre-strain improves the conversion between electrical and mechanical energy. The present invention also relates to devices including an electroactive polymer to convert between electrical and mechanical energy. The present invention further relates to compliant electrodes that conform to the shape of a polymer included in a transducer. The present invention provides methods for fabricating electromechanical devices including one or more electroactive polymers.

The present invention relates to electroactive polymers that are pre-strained to improve conversion from electrical to mechanical energy. When a voltage is applied to electrodes contacting a pre-strained polymer, the polymer deflects. This deflection may be used to do mechanical work. The pre-strain improves the mechanical response of an electroactive polymer. The present invention also relates to actuators including an electroactive polymer and mechanical coupling to convert deflection of the polymer into mechanical work. The present invention further relates to compliant electrodes that conform to the shape of a polymer. The present invention provides methods for fabricating electromechanical devices including one or more electroactive polymers.

The present invention relates to transducers, their use and fabrication. The transducers convert between mechanical and electrical energy. Some transducers of the present invention include a pre-strained polymer. The pre-strain improves the conversion between electrical and mechanical energy. The present invention also relates to devices including an electroactive polymer to convert between electrical and mechanical energy. The present invention further relates to compliant electrodes that conform to the shape of a polymer included in a transducer. The present invention provides methods for fabricating electromechanical devices including one or more electroactive polymers.

A pit (52) is formed in a substrate comprising a silicon wafer (51) on a surface of which a silicon oxide thin layer (53) is formed. A sandwich structure (60) comprising a piezoelectric layer (62) and lower and upper electrodes (61, 63) joined to both surfaces of the piezoelectric layer is disposed so as to stride over the pit (52). The upper surface of the lower electrode (61) and the lower surface of the piezoelectric layer (62) joined to the upper surface of the lower electrode are treated so that the RMS variation of the height thereof is equal to 25 nm or less. The thickness of the lower electrode (61) is set to 150 nm or less. According to such a structure, there is provided a high-performance thin film bulk acoustic resonator which are excellent in electromechanical coupling coefficient and acoustic quality factor.

The invention describes devices for controlling fluid flow, such as valves. The devices may include one or more electroactive polymer transducers with an electroactive polymer that deflects in response to an application of an electric field. The electroactive polymer may be in contact with a fluid where the deflection of the electroactive polymer may be used to change a characteristic of the fluid. Some of the characteristic of the fluid that may be changed include but are not limited to 1) a flow rate, 2) a flow direction, 3) a flow vorticity, 4) a flow momentum, 5) a flow mixing rate, 6) a flow turbulence rate, 7) a flow energy, 8) a flow thermodynamic property. The electroactive polymer may be a portion of a surface of a structure that is immersed in an external fluid flow, such as the surface of an airplane wing or the electroactive polymer may be a portion of a surface of a structure used in an internal flow, such as a bounding surface of a fluid conduit.

Described herein are compliant electroactive polymer transducers for use in acoustic applications. A compliant electroactive polymer transducer includes a compliant electroactive polymer at least two electrodes. For sound production, circuitry in electrical communication with the transducer electrodes is configured to apply a driving signal that causes the electroactive polymer to deflect in the acoustic range.

To provide an electrostatic ultrasonic transducer arranged so that sound wave is not radiated from the rear surface while utilizing advantages of a push-pull type electrostatic ultrasonic transducer. A push-pull type electrostatic ultrasonic transducer includes a vibrating film 11 having a conductive layer and a pair of fixed electrodes 12, 13 provided facing respective surfaces of the vibrating film, and applies a direct current bias voltage to the conductive layer of the vibrating film and applies an alternating current signal between the pair of fixed electrodes so as to allow the vibrating film to generate sound wave and outputting the sound wave generated from the vibrating film from two sound wave output surfaces via through holes provided in the respective pair of fixed electrodes. Plural through holes are provided in the front-side fixed electrode that sandwiches the vibrating film and through holes having the same shapes are provided in the rear-side fixed electrode in positions opposed to the respective through holes provided in the front-side fixed electrode, and a sound absorbing material 16 is provided facing the rear-side fixed electrode.

A sonic actuator including a multi-layer membrane having a non-metallic elastomeric dielectric polymer layer with a first surface and a second surface, a first compliant electrode layer contacting the first surface of the polymer layer, and a second compliant electrode layer contacting the second surface of the polymer layer. The actuator further includes a support structure in contact with the sonic actuator film. Preferably, the non-metallic dielectric polymer is selected from the group consisting essentially of silicone, fluorosilicone, fluoroelastomer, natural rubber, polybutadiene, nitrile rubber, isoprene, and ethylene propylene diene. Also preferably, the compliant electrode layer is made from the group consisting essentially of graphite, carbon, and conductive polymers. The support structure can take the form of grid having a number of circular apertures. When a voltage is applied to the electrodes, portions of the film held at the aperture of the support structure can bulge due to the electrostriction phenomenon. The resultant “bubbles” can be modulated to generate sonic vibrations, or can be used to create a variable surface for airflow control.

A solid-state transducer is disclosed. The transducer comprises a semi-conductor substrate forming a support structure and having an opening. A thin-film structure forming a diaphragm responsive to fluid-transmitted acoustic pressure is disposed over the opening. The transducer further includes a plurality of semi-conductor supports and tangential arms extending from the diaphragm edge for connecting the periphery of the diaphragm to the supports. The tangential arms permit the diaphragm to rotate relative to the supports to relieve film stress in the diaphragm. The transducer still further includes a plurality of stop bumps disposed between the substrate and the diaphragm. The stop bumps determine the separation of the diaphragm from the substrate when the transducer is biased.

The present invention relates to transducers, their use and fabrication. The transducers convert between mechanical and electrical energy. Some transducers of the present invention include a pre-strained polymer. The pre-strain improves the conversion between electrical and mechanical energy. The present invention also relates to devices including an electroactive polymer to convert between electrical and mechanical energy. The present invention further relates to compliant electrodes that conform to the shape of a polymer included in a transducer. The present invention provides methods for fabricating electromechanical devices including one or more electroactive polymers.

The present invention relates to transducers, their use and fabrication. The transducers convert between mechanical and electrical energy. Some transducers of the present invention include a pre-strained polymer. The pre-strain improves the conversion between electrical and mechanical energy. The present invention also relates to devices including an electroactive polymer to convert between electrical and mechanical energy. The present invention further relates to compliant electrodes that conform to the shape of a polymer included in a transducer. The present invention provides methods for fabricating electromechanical devices including one or more electroactive polymers.

The present invention is directed to a structure comprised of alternating layers of metal and sacrificial material built up using standard CMOS processing techniques, a process for building such a structure, a process for fabricating devices from such a structure, and the devices fabricated from such a structure. In one embodiment, a first metal layer is carried by a substrate. A first sacrificial layer is carried by the first metal layer. A second metal layer is carried by the sacrificial layer. The second metal layer has a portion forming a micro-machined metal mesh. When the portion of the first sacrificial layer in the area of the micro-machined metal mesh is removed, the micro-machined metal mesh is released and suspended above the first metal layer a height determined by the thickness of the first sacrificial layer. The structure may be varied by providing a base layer of sacrificial material between the surface of the substrate and the first metal layer. In that manner, a portion of the first metal layer may form a micro-machined mesh which is released when a portion of the base sacrificial layer in the area of the micro-machined mesh is removed. Additionally, a second layer of sacrificial material and a third metal layer may be provided. A micro-machined mesh may be formed in a portion of the third metal layer. The structure of the present invention may be used to construct variable capacitors, switches and, when certain of the meshes are sealed, microspeakers and microphones.

Described herein are compliant electroactive polymer transducers for use in acoustic applications. A compliant electroactive polymer transducer includes a compliant electroactive polymer at least two electrodes. For sound production, circuitry in electrical communication with the transducer electrodes is configured to apply a driving signal that causes the electroactive polymer to deflect in the acoustic range.

This invention relates to one flexible microphone and its process method, which forms sound to same direction with flexible piezoelectricity materials property by flexible driver parts, vibration film, and vibration electrode to overcome traditional technique defaults.

The present invention provides optical systems, devices and methods which utilize one or more electroactive polymer actuators to adjust an optical parameter of the optical device or system.

A capacitive load driving circuit includes an error amplification circuit that amplifies a difference between an external input signal provided to one input terminal and a negative feedback signal provided from the following negative feed back circuit to the other input terminal; a modulation circuit that pulse-modulates the signal outputted from the error amplification circuit; a power switching circuit that switches between a power supply voltage and a ground potential or between a positive power supply voltage and a negative power supply voltage; a gate driving circuit that generates a gate driving signal for switching-controlling a switching element configuring the power switching circuit, from a modulated signal outputted from the modulation circuit; a low-pass filter that is connected to an output side of the power switching circuit and removes switching carrier components included in an output signal of the power switching circuit; an output transformer that boosts an output signal of the low-pass filter and has a primary winding connected to an output terminal of the low-pass filter; a capacitive load that is connected in parallel with a secondary winding of the output transformer; and a negative feedback circuit that performs a negative feedback from the output terminal of the low-pass filter to an input side of the error amplification circuit.

The present invention provides a sound producing device comprising: an air pulse generating element and a control unit. The air pulse generating element comprises an air chamber and an actuator. The control unit, configured to generate a driving voltage applied to the actuator of the air pulse generating element, such that the air pulse generating element generates a plurality of air pulses in response to the driving voltage. The plurality of air pulses are at a pulse rate, and the pulse rate of the plurality of air pulses is higher than a maximum audible frequency.

A vibrating device that can be applied to various purposes other than as a vibrator and that can achieve cost reduction, size reduction, and space saving by a reduction in the number of components, and a mobile phone using this vibrating device are provided. The vibrating device has a housing supported by a base and capable of oscillating in a vibration frequency range of a vibrator, and an expandable rod that can expand and contract, one end of which is fixed to the housing, and the other end of which is a free end contacting the base. The base is resonated by oscillation of the housing in the vibration frequency range of a vibrator, while the base is vibrated by expansion and contraction of the expandable rod in a sound frequency range other than the vibration frequency range of a vibrator.

An electrostatic ultrasonic transducer that includes: a first electrode that is formed with a plurality of holes; a second electrode that is formed with a plurality of holes, and is used in pair with the first electrode; an oscillation film formed with a conductor layer that is sandwiched between the pair of electrodes, and the conductor layer is applied with a direct-current (DC) bias voltage; and a retention member that keeps hold of the pair of electrodes and the oscillation film. In the transducer, an alternating signal is applied between the pair of electrodes, and the pair of electrodes each have a thickness t of about (λ / 4)·n (where k denotes a wavelength of ultrasound, and n denotes a positive odd number).

A two-port air pump speaker that includes at least two active, phase-modulated, bi-directional shutters and an ultrasonic pumping chamber having at least two ports; a first port facing towards the listener, the forward port, and a second port facing another direction, the backward port which may be behind an acoustic baffle or inside a speaker enclosure. A two-port speaker with two active steering shutters can create continuous bi-directional airflow which leads to low distortion reproduction of low audio frequencies. The same improved design can be used also for other applications where acoustic modulation is required, especially in ultrasonic frequencies.

A speaker device comprising an electrostatic emitter film which is responsive to an applied variable voltage to emit sonic output based on a desired sonic signal, used in combination with at least a first foam member having a forward face, an intermediate core section and a rear face. The forward face is composed of a composition having sufficient stiffness to support the electrostatic film and includes conductive properties which enable application of a variable voltage to supply the desired sonic signal. The surface of the forward face includes small cavities having surrounding wall structure defining each cavity which terminates at contacting edges approximately coincident with the forward face of the foam member. The film is applied to the forward face of the foam member and biased in direct contact with the contacting edges of the forward face.

An electrostatic ultrasonic transducer includes a first electrode having a through hole, a second electrode having a through hole, and an oscillation film disposed such that the through hole of the first electrode can be paired with the through hole of the second electrode and sandwiched between the pair of the first electrode and second electrode. The oscillation film has an electrode layer to which direct current bias voltage is applied. Each of the pair of the electrodes has an electrode portion at a position in the periphery of the through hole. An alternating current signal is applied between the pair of the electrodes and the electrode layer of the oscillation film.

An electrostatic transducer includes: a class-D power amplifier that amplifies an input signal; and a low pass filter that has a plurality of pairs of inductors and capacitors, is connected to an output side of the class-D power amplifier, and serves to eliminate switching carrier components included in an output of the class-D power amplifier. An electrostatic load capacitor of the electrostatic transducer serving as a driving load is disposed at a capacitor, which is closest to the output side of the class-D power amplifier, of circuit elements forming the low pass filter, an electrostatic coupling capacitor and an output transformer are interposed between the electrostatic load capacitor of the electrostatic transducer and an inductor closest to the output side of the class-D power amplifier of the low pass filter, and a damping resistor is connected in series to a primary coil of the output transformer.

A loudspeaker in which the voice coil diameter is so large that the voice coil is axially beneath the suspension roll of the surround. The surround has an overlapping suspension roll such that the inner portion of the surround is coupled to the diaphragm well inward of the bobbin. Such a transducer having greatly extended low frequency abilities by virtue of its wider, softer suspension roll enabling a much lower resonant frequency, and by virtue of its maximum sized magnet and voice coil yielding increased motor strength and power handling. Additionally, the dome diaphragm can now be vented through the portion of the dome that is beneath the surround roll, releasing the trapped back pressure below the diaphragm, thereby further lowering the resonant frequency.