With Electrostatic Loudspeaker Patents (Class 381/116)
  • Patent number: 8284964
    Abstract: A compound membrane (100) for an acoustic device (200), the compound membrane (100) comprising a first layer (101) and a second layer (102), wherein a value of Young's modulus of the second layer (102) does not vary more than essentially 30% in a temperature range between essentially ?20° C. and essentially +85° C.
    Type: Grant
    Filed: October 16, 2007
    Date of Patent: October 9, 2012
    Assignee: Knowles Electronics Asia PTE. Ltd.
    Inventors: Susanne Windischberger, Josef Lutz, Ewald Frasl
  • Patent number: 8238580
    Abstract: The present invention provides a module for a powered speaker, such as a subwoofer that may be actuated to turn the speaker on and off remotely by energizing the auxiliary AC power supply provided with an audio device or other source unit. The main power of the module is provided via a wall outlet or suitable power supply that may adequately supply the necessary power.
    Type: Grant
    Filed: October 17, 2005
    Date of Patent: August 7, 2012
    Inventor: Richard Hofrichter
  • Patent number: 8238581
    Abstract: The present invention provides a powered speaker, such as a subwoofer that may be turned on and off remotely by energizing the auxiliary AC power supply provided with an audio device or other source unit. The main power of the powered subwoofer is provided via a wall outlet or suitable power supply that may adequately supply the necessary power.
    Type: Grant
    Filed: October 17, 2005
    Date of Patent: August 7, 2012
    Inventor: Richard Hofrichter
  • Patent number: 8204260
    Abstract: The present invention provides a sound producing apparatus which suppresses an increase in electric power consumption and cost, and an increase in a number of wiring when a plurality of speaker apparatuses is configured. A speaker driving apparatus supplies electric power to a speaker apparatus, acquires information about an electroacoustic characteristic and maximum input electric power of each speaker apparatus from the speaker apparatus, and executes characteristic correction and output electric power restriction according to the information.
    Type: Grant
    Filed: January 16, 2008
    Date of Patent: June 19, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventor: Noriaki Suzuki
  • Publication number: 20120148071
    Abstract: A digital loudspeaker includes a substrate, a first stator fixed with respect to the substrate, a second stator fixed with respect to the substrate and spaced at a distance from the first stator, and a membrane between the first stator and the second stator. The membrane is displaceable between a first position in which the membrane mechanically contacts the first stator and a second position in which the membrane mechanically contacts the second stator. The first stator and the second stator are arranged to electrostatically move the membrane from a rest position spaced apart from the first position and the second position to the first position and the second position, respectively.
    Type: Application
    Filed: December 10, 2010
    Publication date: June 14, 2012
    Inventor: Alfons Dehe
  • Patent number: 8184833
    Abstract: A speaker is integrally formed with a multi-layered printed circuit board. The printed circuit board includes a flexible membrane layer with a conductive pattern thereon. Positive and negative elements are disposed on opposing sides of the flexible membrane. A drive circuit connects to the flexible membrane layer and applies current to the flexible membrane layer responsive to an audio signal to generate audible sounds.
    Type: Grant
    Filed: December 14, 2007
    Date of Patent: May 22, 2012
    Assignee: Sony Ericsson Mobile Communications AB
    Inventor: Randolph Cary Demuynck
  • Patent number: 8175294
    Abstract: An electrostatic loudspeaker includes a front stator, first and second substantially conductive diaphragms, a center stator and a back stator. The front stator is connected to a safe reference potential such as earth ground. The first diaphragm, the center stator and the back stator are connected to individual positive, non equal DC bias voltages, referenced to the front stator. The second diaphragm is connected to a negative DC bias voltage. A high voltage audio signal, which is referenced to the front stator, is superimposed to the bias voltage of the center stator. The electrostatic loudspeaker can be driven by a single ended audio source. The electrostatic loudspeaker further features an improved electrical safety level.
    Type: Grant
    Filed: May 2, 2008
    Date of Patent: May 8, 2012
    Inventor: Arian M. Jansen
  • Patent number: 8150091
    Abstract: A flat-panel speaker is attached to an exterior surface of a printed circuit board (PCB) housed within a consumer electronic device. Rather than place the flat-panel speaker within a sealed speaker box and then attach the speaker box to the PCB, as is conventional, the present invention attaches the flat-panel speaker to the exterior surface of the PCB without the speaker box. Removing the speaker box allows designers to reduce the dimensions of the device, and to minimize the complexity of the device.
    Type: Grant
    Filed: December 14, 2007
    Date of Patent: April 3, 2012
    Assignee: Sony Ericsson Mobile Communications AB
    Inventors: William Chris Eaton, Eric Douglas Romesburg
  • Patent number: 8130973
    Abstract: A superdirectional acoustic system for reproducing a sound signal supplied from a real sound source by using a superdirectional speaker and producing a virtual sound source in a vicinity of a sound wave reflection surface. The system includes an ultrasonic speaker, which includes an ultrasonic transducer for oscillating a sound wave in an ultrasonic frequency band, for reproducing an audio signal in a relatively medium to high frequency sound range, which is included in the sound signal supplied from the real sound source; and a low frequency sound reproducing speaker for reproducing an audio signal in a relatively low frequency sound range, which is included in the sound signal supplied from the real sound source. Sound in the medium-high frequency range is reproduced in a manner such that the sound is produced from a virtual sound source which is formed in the vicinity of the sound signal reflection surface such as a screen.
    Type: Grant
    Filed: June 20, 2005
    Date of Patent: March 6, 2012
    Assignee: Seiko Epson Corporation
    Inventors: Akihito Uetake, Kinya Matsuzawa
  • Patent number: 8126171
    Abstract: An electrostatic ultrasonic transducer includes a first electrode that has through-holes, a second electrode that has through-holes, and a vibrating membrane that is disposed such that the through-holes of the first electrode and the through-holes of the second electrode form a pair, interposed between a pair of electrodes composed of the first electrode and the second electrode, and having a conductive layer applied with a direct current bias voltage. The first electrode and the second electrode each have counter electrode portions that are formed in the through-holes to face the vibrating membrane, and a modulated wave, which is obtained by modulating a carrier wave in an ultrasonic frequency band with a signal wave in an audible frequency band, is applied between the pair of electrodes.
    Type: Grant
    Filed: February 21, 2007
    Date of Patent: February 28, 2012
    Assignee: Seiko Epson Corporation
    Inventors: Hirokazu Sekino, Kinya Matsuzawa, Hideki Kojima
  • Patent number: 8121315
    Abstract: Disclosed is a condenser microphone chip, comprising: a substrate (21); a diaphragm (26) spaced from the substrate; a curved beam (27) connected with the diaphragm (26) to anchor the diaphragm (26) to the substrate (21); a curved beam connecting part (29) having a shape of a substantially circular plate. The curved beam (27) is arranged in the diaphragm (26). The curved beam (27) includes a plurality of sub beams, each of the plurality of sub beams including a first sub beam portion extending in a substantially radial direction from a circumference of the curved beam connecting part (29); a second sub beam portion extending in a substantially circumferential direction from an end of the first sub beam portion away from the circumference of the curved beam connecting part (29) and having a shape of a substantial arc; and a third sub beam portion extending in the radial direction from an end of the second sub beam portion away from the first sub beam portion and connected to the diaphragm (26).
    Type: Grant
    Filed: October 30, 2007
    Date of Patent: February 21, 2012
    Assignee: Goer Tek Inc.
    Inventors: Qinglin Song, Yongchun Tao, Shengli Pang, Tongqing Liu
  • Patent number: 8103037
    Abstract: A system for producing parameters for a bass-enhanced loudspeaker enclosure; meanwhile, a low-frequency extended frequency, a quality and quantity ratio and radius of a port need to be defined for the system. Also, the resonance frequency of a mechanical system and the quality and quantity of a mechanical system are fixed to obtain the parameters for the frequency ratio, the length of the duct and the cavity volume inside the device, etc. and to manufacture the bass-enhanced loudspeaker enclosure.
    Type: Grant
    Filed: February 21, 2008
    Date of Patent: January 24, 2012
    Assignee: National Chiao Tung University
    Inventors: Ming-Sian R. Bai, Huan-Sheng Zhang, Rong-Liang Chen
  • Patent number: 8085957
    Abstract: The invention relates to electroacoustic engineering, in particular to methods for converting electric signals into acoustic oscillations and to electroacoustic transducers. The method for converting electric signals into acoustic oscillations comprises exposing an oscillating system that is a gas medium pre-structured by a static electric field to an electric/electromagnetic field modulated in strength by an alternating electric signal in accordance with the shape and frequency of the modulating signal, and converting the energy of the field into acoustic energy to be released thereupon into the ambient. An electric gas-kinetic transducer developed to perform this method comprises a dielectric working element and at least two current-conducting plates that can be connected to the pole terminals of a direct voltage source and to a source of alternating electric signals.
    Type: Grant
    Filed: November 10, 2006
    Date of Patent: December 27, 2011
    Inventors: Sergey Vladimirovich Shishov, Sergey Alexandrovich Andrianov, Sergey Pavlovich Dmitriev, Dmitriy Victorovich Ruchkin
  • Patent number: 8081779
    Abstract: An object is to provide an audio circuit in which flow of excessive current through a capacitive speaker and a drive circuit thereof can be prevented while degradation of sound quality of high-pitched tones is suppressed. The audio circuit for driving a capacitive speaker includes: a weighting circuit for performing weighting in conformity with frequency components of an audio signal; and a signal-voltage limiting compression circuit for compressing a signal, which is input to the drive amplifier or which has been output from the drive circuit, at a prescribed compression ratio in accordance with a difference voltage between the output signal of the weighting circuit and a preset threshold voltage when the weighted signal exceeds the threshold voltage.
    Type: Grant
    Filed: March 14, 2007
    Date of Patent: December 20, 2011
    Assignee: NEC Corporation
    Inventors: Jun Kuroda, Yukio Murata, Ukyo Mori, Satoshi Hosokawa
  • Patent number: 8068622
    Abstract: A method and apparatus for controlling a selectable voltage audio power output stage provides a mechanism for raising the selected power amplifier output voltage in time for the arrival of signal peaks to avoid clipping. Signal peaks may either be delayed by delaying an increase in volume control level or enabling signal compression for a predetermined time period, so that sufficient time is provided for the amplifier power supply to stabilize at a higher operating voltage when an increase of power supply voltage is selected. Alternatively, a signal level may be determined at an upstream source, such as a decoder or filter that provides information in sufficient advance of the arrival of the peaks, and used to control the power supply selection, so that the higher power supply voltage level is selected in advance of arrival of the signal peaks that would otherwise cause clipping at the power amplifier output.
    Type: Grant
    Filed: December 14, 2006
    Date of Patent: November 29, 2011
    Assignee: Cirrus Logic, Inc.
    Inventors: John L. Melanson, John Christopher Tucker
  • Patent number: 8064620
    Abstract: The present invention discloses a driver circuit for an electrostatic loudspeaker, comprising: a digital modulation encoder for receiving a digital audio signal and a fixed frequency pulse signal, and mixing them by modulation; a digital to analog converter for converting the output of the digital modulation encoder to an analog signal; a transformer for adjusting the voltage amplitude of the analog signal; and a demodulator for demodulating the adjusted analog signal to driver a speaker.
    Type: Grant
    Filed: August 22, 2008
    Date of Patent: November 22, 2011
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Pei-Cheng Huang, Jwin-Yen Guo, Kuo-Chi Liu
  • Patent number: 8054995
    Abstract: A system and method for modulating the sound pressure that is output from an audio transducer is disclosed. In one embodiment, the method includes receiving an audio signal and placing the audio signal across a voice coil of the transducer. In addition, a voltage is applied across a field coil of the transducer, the field coil being separate from the voice coil. And the voltage that is applied across the field coil is adjusted so as to modulate the sound pressure output from the audio transducer.
    Type: Grant
    Filed: June 26, 2007
    Date of Patent: November 8, 2011
    Assignee: Fluxtone, Inc.
    Inventor: Stephen L. Carey
  • Patent number: 8041059
    Abstract: 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.
    Type: Grant
    Filed: November 22, 2006
    Date of Patent: October 18, 2011
    Assignee: Seiko Epson Corporation
    Inventor: Shinichi Miyazaki
  • Patent number: 8027488
    Abstract: Ultrasonic signals are used to transmit sounds from a modulated ultrasonic generator to other locations from which the sounds appear to emanate. In particular, an ultrasonic carrier is modulated with an audio signal and demodulated on passage through the atmosphere. The carrier frequencies are substantially higher than those of prior systems, e.g., at least 60 kHz, and the modulation products thus have frequencies which are well above the audible range of humans; as a result, these signals are likely harmless to individuals who are within the ultrasonic fields of the system. The signals may be steered to moving locations, and various measures are taken to minimize distortion and maximize efficiency.
    Type: Grant
    Filed: July 13, 2005
    Date of Patent: September 27, 2011
    Assignee: Massachusetts Institute of Technology
    Inventor: F. Joseph Pompei
  • Patent number: 8023671
    Abstract: A piezoelectric buzzer driving circuit (200) for driving a piezoelectric buzzer (211) with two terminals includes a reverser (216). The reverser includes an output terminal and an input terminal (24) configured for receiving a controlling signal to control an output of the reverser. The two terminals of the piezoelectric buzzer respectively connected to the input terminal and the output terminal such that a D-value of the voltage across the piezoelectric buzzer is twice as large as the voltage of the controlling signal.
    Type: Grant
    Filed: October 24, 2007
    Date of Patent: September 20, 2011
    Assignees: Premier Image Technology(China) Ltd., Hon Hai Precision Industry Co., Ltd.
    Inventor: Zhen Hou
  • Patent number: 8000483
    Abstract: Embodiments of an electrostatic loudspeaker utilize first and second stators and a diaphragm disposed therebetween, each of the stators and the diaphragm having an electrically conductive portion, wherein the conductive portions of the first stators are electrically coupled to each other; the conductive portions of the second stators are electrically coupled to each other; and the conductive portions of the diaphragms are electrically isolated from each other. The first stators and the second stators may be realized by common first and second stators may be mounted obliquely with respect to one another, so as to achieve differentially greater spacing between stators of the first one of the speaker elements than between stators of the second one of the speaker elements. Protective circuitry is also provided.
    Type: Grant
    Filed: December 29, 2006
    Date of Patent: August 16, 2011
    Assignee: Transparent Sound Technology B.V.
    Inventors: Hidde de Haan, James Tuomy, Ronald Buining, Gaston Bastiaens, Ton Hoogstraaten
  • Patent number: 7953460
    Abstract: A mobile terminal having a dual display unit, a dual speaker and a dual microphone, and a method of controlling the dual speaker and the dual microphone thereof are provided. The method of controlling a dual speaker and a dual microphone of a mobile terminal having a dual display unit including a first body having a first display unit and first speaker on a front surface and a second display unit and second speaker on a rear surface, a second body having a first and a second microphone, and a hinge module for rotatably connecting the first body and the second body, includes determining which of the first and second display units is activated; activating, if the first display unit is activated, the first speaker; and activating, if the second display unit is activated, the second speaker.
    Type: Grant
    Filed: November 20, 2007
    Date of Patent: May 31, 2011
    Assignee: Samsung Electronics Co., Ltd
    Inventor: Jeong Min You
  • Publication number: 20110116657
    Abstract: An electrostatic transducer loudspeaker includes a filterless class-D amplifier to modulate an audio input signal to generate a modulated signal containing a PWM switching carrier component, and a transformer directly connected at an output side of the filterless class-D amplifier and directly connected at an input side of an electrostatic transducer, whereby the equivalent capacitance of the electrostatic transducer and the equivalent inductance of the transformer establish a resonance circuit to demodulate the modulated signal to generate an AC voltage to drive the electrostatic transducer.
    Type: Application
    Filed: November 16, 2010
    Publication date: May 19, 2011
    Applicant: RICHTEK TECHNOLOGY CORP.
    Inventors: PEI-CHENG HUANG, JWIN-YEN GUO
  • Patent number: 7945059
    Abstract: A speaker device mixes an audible frequency band signal wave with a modulated wave obtained by modulating an ultrasonic frequency band carrier wave with an audible frequency band signal so as to generate a synthesis wave, and drives an ultrasonic transducer with the synthesis wave so as to reproduce a signal sound.
    Type: Grant
    Filed: March 2, 2007
    Date of Patent: May 17, 2011
    Assignee: Seiko Epson Corporation
    Inventor: Shinichi Miyazaki
  • Patent number: 7926163
    Abstract: An oscillator device having an oscillating member, a resilient support and a supporting member is produced. The oscillating member is supported by the resilient support for oscillation about an oscillation axis. The oscillating member is formed with a movable element having protrusions for adjusting its mass, the protrusions extending from the movable element parallel to the oscillation axis and being formed in pairs disposed at positions symmetrical with respect to the oscillation axis. A sectional area of each protrusion along a plane perpendicular to the oscillation axis is constant in the oscillation axis direction. A laser beam is projected to a cutting position of protrusions, so as to partly remove the protrusion. The protrusions are cut based on adjusting the cutting position. The sum of the lengths removed from the protrusions by the cutting becomes equal to a predetermined length to thereby adjust an inertia moment of the oscillating member.
    Type: Grant
    Filed: June 9, 2009
    Date of Patent: April 19, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takahisa Kato, Yukio Furukawa, Takahiro Akiyama
  • Patent number: 7925033
    Abstract: The present invention provides a stable and excellent electro-acoustic transducer having simple constitution with which a vibration pole does not contact with stator poles by a repulsive force acting between the vibration pole and the stator poles and the vibration pole can be stably positioned in place between the two stator poles. A vibration pole is disposed between two stator poles, and surfaces of the vibration pole and the two stator poles facing to each other have electrostatically same polarity to generate an electrostatic repulsive force as a restorative force acting between the vibration pole and the stator poles, so that the vibration pole is positioned in place and electro-acoustic conversion is performed by the vibration displacement of the vibration pole with respect to the stator poles. Whereby, the vibration pole does not contact substantially with the stator poles and the vibration pole is stably positioned in place.
    Type: Grant
    Filed: November 24, 2006
    Date of Patent: April 12, 2011
    Inventor: Hiroshi Okazawa
  • Patent number: 7909466
    Abstract: A projector includes an ultrasonic speaker, a visual information generation unit that generates visual information relating to a sound reproduction range of the ultrasonic speaker, and an image projection unit that displays the visual information generated by the visual information generation unit on a screen.
    Type: Grant
    Filed: February 16, 2005
    Date of Patent: March 22, 2011
    Assignee: Seiko Epson Corporation
    Inventors: Yoshiki Fukui, Akihito Uetake
  • Patent number: 7899197
    Abstract: Provided is an electrostatic transducer which is driven by a boosted driving signal by boosting a modulated signal obtained by modulating a carrier wave with an acoustic signal in an audio frequency band, the transducer including: an output transformer T which connects the electrostatic transducer to a secondary side winding thereof in parallel and boosts the modulated signal; and a resistor R and a coupling capacitance C1 connected in series to a primary side winding of the output transformer T, wherein a circuit constant of a primary side circuit of the output transformer T including a serial circuit of the resistor R and the coupling capacitance C1 and a circuit constant of a secondary side circuit of the output transformer including a self-inductance L2 and a load capacitance CL of the secondary side winding of the output transformer T are set such that a resonance frequency f0 of a circuit formed by the self-inductance L2 of the secondary side winding of the output transformer T and the load capacitance
    Type: Grant
    Filed: November 9, 2006
    Date of Patent: March 1, 2011
    Assignee: Seiko Epson Corporation
    Inventor: Shinichi Mayazaki
  • Patent number: 7804971
    Abstract: The present invention relates to a push-pull type electrostatic ultrasonic transducer, particularly, an electrostatic ultrasonic transducer capable of generating usual sound pressure with lower energy, and thereby, reducing voltage (lowering power); wherein the spacing between the electrodes and vibrating film is set to a specific distance.
    Type: Grant
    Filed: September 26, 2006
    Date of Patent: September 28, 2010
    Assignee: Seiko Epson Corporation
    Inventor: Kinya Matsuzawa
  • Patent number: 7716808
    Abstract: Electro-dynamic loudspeakers typically include a diaphragm having a conductor applied to one of its surfaces where the diaphragm is secured to a frame. The conductor is connected to a power supply for providing electrical current through linear traces of the conductor that interact with magnetic fields generated by magnets that are mounted to the frame. The diaphragm is driven by a motive force created when current passes through the conductor within the magnetic field. The electrical current is varied to create an acoustical output from the electro-dynamic loudspeaker. Different methods of attaching the diaphragm are provided for simplifying the manufacturing process and for obtaining a robust electro-dynamic loudspeaker.
    Type: Grant
    Filed: December 28, 2007
    Date of Patent: May 18, 2010
    Assignee: Harman International Industries, Incorporated
    Inventors: Steven W. Hutt, John F. Steere, David B. Garner, Louis A. Mango
  • Patent number: 7685696
    Abstract: The invention relates to a method for the manufacture of a sensor element and to a sensor element. In the method, both surfaces of a sensor film are provided with metallic electrodes. The sensor element is produced by cutting it from a larger amount of sensor element material. In the manufacture of the sensor element material, the electrodes are produced as a continuous process from roll to roll and the sensor element material is formed by laminating as a continuous process from roll to roll. At least the signal electrode consists of repeated electrode patterns (41) which are at least partially connected to each other via one or more narrow connecting strips (42), and a sensor element of a desired length and/or shape is produced by cutting the material across the region of the connecting strips.
    Type: Grant
    Filed: November 23, 2004
    Date of Patent: March 30, 2010
    Assignee: Emfitech Oy
    Inventor: Heikki Räisänen
  • Patent number: 7685695
    Abstract: A method of producing a speaker which is manufactured by bonding a plurality of speaker components, including steps of humidifying a joint portion which bonds at least two speaker components among the plurality of speaker components; and bonding the speaker components by humidifying the joint portion and thereafter painting a moisture-curable adhesive on the joint portion, to thereby reduce a time for bonding the speaker components by easily and quickly drying regardless of materials of the speaker components.
    Type: Grant
    Filed: May 25, 2007
    Date of Patent: March 30, 2010
    Assignees: Pioneer Corporation, Tohoku Pioneer Corporation
    Inventor: Kawori Kishi
  • Patent number: 7668320
    Abstract: The present invention is directed towards a portable electronic equipment (10) comprising a speaker (16) and a receiver (18), wherein the receiver (18) is damped while the speaker (16) is active to provide good sound reproduction.
    Type: Grant
    Filed: January 21, 2005
    Date of Patent: February 23, 2010
    Assignee: Sony Ericsson Mobile Communications AB
    Inventor: Stefan Gustavsson
  • Patent number: 7630505
    Abstract: There is provided a low-cost loudspeaker system which can adjust attenuation and provide protection against an excessive input. Between input terminals and a loudspeaker unit is provided a serial circuit including a plurality of resistor elements. A switch is provided which can switch between connected and disconnected states of two points, which includes one or more resistor elements of the serial circuit therebetween, through an over-current protection element.
    Type: Grant
    Filed: December 17, 2004
    Date of Patent: December 8, 2009
    Assignee: Alpine Electronics, Inc.
    Inventor: Naoki Shimamura
  • Publication number: 20090154730
    Abstract: A speaker is integrally formed with a multi-layered printed circuit board. The printed circuit board includes a flexible membrane layer with a conductive pattern thereon. Positive and negative elements are disposed on opposing sides of the flexible membrane. A drive circuit connects to the flexible membrane layer and applies current to the flexible membrane layer responsive to an audio signal to generate audible sounds.
    Type: Application
    Filed: December 14, 2007
    Publication date: June 18, 2009
    Applicant: Sony Ericsson Mobile Communications AB
    Inventor: Randolph Cary Demuynck
  • Patent number: 7536769
    Abstract: An acoustic pressure type sensor is fabricated on a supporting substrate by depositing and etching a number of thin films on the supporting substrate and by machining the supporting substrate. The resulting structure contains a pressure sensitive, electrically conductive diaphragm positioned at a distance from an electrically conductive fixed electrode. In operation, the diaphragm deflects in response to an acoustic pressure and the corresponding change of electrical capacitance between the diaphragm and the fixed electrode is detected using an electrical circuit. Two or more such acoustic sensors are combined on the same supporting substrate with an interaural flexible mechanical connection, to form a directional sensor with a small surface area.
    Type: Grant
    Filed: May 25, 2006
    Date of Patent: May 26, 2009
    Assignee: Corporation for National Research Initiatives
    Inventor: Michael Pedersen
  • Publication number: 20090080676
    Abstract: The present invention discloses a driver circuit for an electrostatic loudspeaker, comprising: a digital modulation encoder for receiving a digital audio signal and a fixed frequency pulse signal, and mixing them by modulation; a digital to analog converter for converting the output of the digital modulation encoder to an analog signal; a transformer for adjusting the voltage amplitude of the analog signal; and a demodulator for demodulating the adjusted analog signal to driver a speaker.
    Type: Application
    Filed: August 22, 2008
    Publication date: March 26, 2009
    Inventors: Pei-Cheng Huang, Jwin-Yen Guo, Kuo-Chi Liu
  • Patent number: 7505600
    Abstract: A controller, either a microprocessor or finite state machine, is used to generate a pulse train whose frequency and duty cycle can be varied to alter the frequency and amplitude of the output of a driven audio transducer. The ability to control both frequency and amplitude allows programmatic synthesis of many audio effects such as steady tones, warbles, beeps, sirens and chimes with no hardware or circuit changes. The transducer can be a piezoelectric bender or a speaker. The output of the controller controls a switch that builds current in an inductor when the switch is on. When the switch is turned off, the energy stored in the inductor is dumped into the audio transducer, either directly or through intermediate capacitor storage. This allows the generation of voltages across the transducer many times the supply voltage.
    Type: Grant
    Filed: March 30, 2005
    Date of Patent: March 17, 2009
    Assignee: Floyd Bell, Inc.
    Inventor: Joseph E. Dryer
  • Publication number: 20080285777
    Abstract: A parametric audio system having increased bandwidth for generating airborne audio signals with reduced distortion. The parametric audio system includes a modulator for modulating an ultrasonic carrier signal with a processed audio signal, a driver amplifier for amplifying the modulated carrier signal, and an array of acoustic transducers for projecting the modulated and amplified carrier signal through the air along a selected projection path to regenerate the audio signal. The acoustic transducer array includes a backplate having a succession of depressions formed thereon with at least one varying feature and/or dimension, and a membrane disposed along the backplate. The feature and/or dimension of the respective depressions vary so that the center frequencies of the respective acoustic transducers span a desired frequency range, thereby broadening the frequency response of the acoustic transducer array.
    Type: Application
    Filed: June 20, 2008
    Publication date: November 20, 2008
    Inventor: Frank Joseph Pompei
  • Publication number: 20080279398
    Abstract: An electrostatic loudspeaker includes a front stator, first and second substantially conductive diaphragms, a center stator and a back stator. The front stator is connected to a safe reference potential such as earth ground. The first diaphragm, the center stator and the back stator are connected to individual positive, non equal DC bias voltages, referenced to the front stator. The second diaphragm is connected to a negative DC bias voltage. A high voltage audio signal, which is referenced to the front stator, is superimposed to the bias voltage of the center stator. The electrostatic loudspeaker can be driven by a single ended audio source. The electrostatic loudspeaker further features an improved electrical safety level.
    Type: Application
    Filed: May 2, 2008
    Publication date: November 13, 2008
    Inventor: Arian M. Jansen
  • Patent number: 7447318
    Abstract: This invention provides a compensation system capable of compensating for power loss due to the power compression effects of the voice coil as the temperature of the voice coil increases. To compensate for the power compression effect, the invention predicts or estimates the temperature of the voice coil using a thermal-model, and adjusts the estimated temperature according to the cooling effect as the voice coil moves back and forth in the air gap. The thermal-model may be an equivalent electrical circuit that models the thermal circuit of a loudspeaker. With the input signal equating to the voltage delivered to the loudspeaker, the thermal-model estimates a temperature of the voice coil. The estimated temperature is then used to modify equalization parameters.
    Type: Grant
    Filed: September 7, 2001
    Date of Patent: November 4, 2008
    Assignee: Harman International Industries, Incorporated
    Inventors: Douglas J. Button, Paul Robert Williams
  • Patent number: 7443990
    Abstract: A voltage biased capacitor circuit (10) for a loudspeaker (14?) includes at least two audio circuit capacitors (32A, 32B) wired in series either on one of an audio connector or between audio connectors (16A?, 16B?). A direct current voltage source (34) is wired in electrical communication with the audio circuit capacitors (32A, 32B) for transmitting through direct current voltage connectors (36A, 36B) a direct current to provide a bias voltage to the audio circuit capacitors (32A, 32B). At least one resistor (37) is secured between the audio circuit capacitors (32A, 32B) and the voltage source (34), to prevent dissipation of an audio signal through the resistor (37) and direct current voltage connectors (36A, 36B). A voltage source capacitor (40) is also wired between the voltage source (34) and the audio connectors (16A? 16B?) to stabilize the direct current transmitted to the capacitors (32A, 32B).
    Type: Grant
    Filed: November 1, 2004
    Date of Patent: October 28, 2008
    Inventor: Daniel A. Chattin
  • Publication number: 20080152172
    Abstract: 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.
    Type: Application
    Filed: December 19, 2007
    Publication date: June 26, 2008
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Kinya MATSUZAWA
  • Patent number: 7321661
    Abstract: A loudspeaker is provided for receiving an incoming electrical signal and transmitting an acoustical signal. The loudspeaker may include a power amplifier that has an input and an output, where the input receives the incoming electrical signal. The loudspeaker may also include two or more passive filters, such as low-pass, band-pass, and/or high-pass filters, which are coupled to the output of the power amplifier. The passive filters may also be coupled to one or more speaker drivers. The arrangement of passive filters and speaker drivers may have a single input that has a combined input impedance. The output of the amplifier may have an output impedance. The output impedance may be between about 25% and about 400% of the combined input impedance. The power amplifier may include a current-feedback amplifier that is configured to maintain the desired output impedance.
    Type: Grant
    Filed: October 30, 2003
    Date of Patent: January 22, 2008
    Assignee: Harman International Industries, Incorporated
    Inventor: Gerald R. Stanley
  • Patent number: 7308750
    Abstract: In a rolling process, the level of rolling performed by a rolling mill for one operation is set to 1 ?m to 20 ?m. A magnesium substrate is rolled by rollers while being heated by a thermostatic chamber. As a result, there is manufactured a high-quality magnesium sheet which is less susceptible to influence of oxidation, which realizes a high internal loss, prevention of a drop in sensitivity, and low distortion, and which has a thickness of 30 ?m to 100 ?m. Further, as a result of the magnesium sheet being formed into a semi-dome shape or a dome shape, the sheet can be inexpensively manufactured as a speaker for high-tone playback. In particular, in the case of a magnesium diaphragm into which a dome section and an edge section are integrally formed, high-quality sound can be played back in a high frequency range without involvement of a drop in sensitivity.
    Type: Grant
    Filed: May 12, 2004
    Date of Patent: December 18, 2007
    Assignees: Pioneer Corporation, Tohoku Pioneer Corporation
    Inventors: Hiroyuki Tomiyama, Masatoshi Sato, Yoshimi Kudo, Yuichi Kasahara
  • Patent number: 7305750
    Abstract: A loudspeaker and method of assembly according to this invention provides for precise alignment between the frame and motor structure before they are connected to one another, and employs a fixture to form the moving assembly of the speaker, i.e. the voice coil, upper and lower suspensions and diaphragm, outside of the frame so that concentric tolerance stack-up is minimized. The moving assembly, once formed, is mounted as a unit to the frame and motor structure to facilitate assembly and repair of the speaker.
    Type: Grant
    Filed: February 18, 2004
    Date of Patent: December 11, 2007
    Assignee: JL Audio, Inc.
    Inventor: Lucio Proni
  • Patent number: 7278200
    Abstract: Electro-dynamic loudspeakers typically include a diaphragm having a conductor applied to one of its surfaces. The diaphragm is secured to a frame. The conductor is connected to a power supply for providing electrical current through linear traces of the conductor that interact with magnetic fields generated by magnets that are mounted to the frame. The diaphragm is driven by a motive force created when current passes through the conductor within the magnetic field. The electrical current is varied to create an acoustical output from the electro-dynamic loudspeaker. Different methods of tensioning the diaphragm are provided for simplifying the manufacturing process and for assuring proper diaphragm tension.
    Type: Grant
    Filed: May 2, 2003
    Date of Patent: October 9, 2007
    Assignee: Harman International Industries, Incorporated
    Inventors: John F. Steere, David B. Garner
  • Publication number: 20070230718
    Abstract: An apparatus includes two DC/DC converters including two conversion circuits for converting a power supply voltage to first and second output voltages, respectively, two driving circuits for driving the respective conversion circuit based on first and second pulse wave modulated signals, and two pulse width modulation circuits for performing pulse width modulation on a thinned wave signal formed from a first wave signal and on a second wave signal to generate the pulse wave modulated signals, respectively. One DC/DC converter includes a thinning circuit for removing portions of a first wave signal to form the thinned wave signal. The apparatus includes a speaker for generating sound by inputting a signal based on the voltages.
    Type: Application
    Filed: March 29, 2007
    Publication date: October 4, 2007
    Applicant: BROTHER KOGYO KABUSHIKI KAISHA
    Inventor: Naoki Oda
  • Patent number: 7216417
    Abstract: Method for manufacturing an electromechanical sensor element for converting mechanical forces produced by the movements and vital functions or a person into electric signals, in which method a sensor film (11) is provided with metallic electrodes (15,16) placed on either side of it, at least one of said electrodes being a signal electrode, in which method is produced by cutting off a larger amount of sensor element material, in which method in the manufacture of sensor element material the electrodes are created in a continuous roll-to-roll process, and in which method the sensor element material is produced by laminating as a continuous roll-to-roll process. At least the sensor element material consists of repeated electrode patterns and a sensor element of a desired size and/or shape is formed by cutting the material between the patterns.
    Type: Grant
    Filed: October 4, 2002
    Date of Patent: May 15, 2007
    Assignee: Emfitech Oy
    Inventor: Heikki Raisanen
  • Patent number: 7210213
    Abstract: A speaker collective substrate with component insertion hole sections and electrode sections has a plurality of speaker forming areas. An electrical speaker section, which comprises a magnetic circuit section and a vibration section, is inserted into each of the component insertion hole sections. Then, a collective lid, in which a plurality of lids have been formed for sealing the electrical speaker sections, is attached onto the speaker collective substrate. After that, the speaker collective substrate and the collective lid are divided into individual speaker forming areas along partition lines extending in the directions of the X and Y axes to form individual dynamic speakers. Thus, it is possible to mass-produce dynamic speakers with uniform quality through a collectively manufacturing process.
    Type: Grant
    Filed: July 28, 2004
    Date of Patent: May 1, 2007
    Assignee: Citizen Electronics Co., Ltd.
    Inventors: Kazumi Miyamoto, Naoki Miura