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6568 results about "Voice coil" patented technology

A voice coil (consisting of a former, collar, and winding) is the coil of wire attached to the apex of a loudspeaker cone. It provides the motive force to the cone by the reaction of a magnetic field to the current passing through it. The term is also used for voice coil linear motors, such as those used to move the heads inside hard disk drives, which produce a larger force and move a longer distance but work on the same principle.

Position detection of an actuator using a capacitance measurement

Control system for devices such as an audio reproduction system, an actuator device, an electromechanical device and a telephony device. The system includes control circuitry which receives an input signal and a signal indicative of a position of a portion of the controlled apparatus. The control circuit provides an output signal to the controlled apparatus to affect an operation of the controlled apparatus. The output signal provides control of the apparatus to compensate for one or more of: motor factor; spring factor; back electromotive force; and impedance of a coil in a driver of the controlled apparatus. The signal indicative of position is derived by one or more position indicator techniques such as an infrared LED and PIN diode combination, position dependent capacitance of one portion of the controlled apparatus with respect to another portion of the controlled apparatus, and impedance of a coil in the controlled apparatus. The control circuitry is configurable to control transconductance and / or transduction of the system being controlled. A technique is disclosed to detect and measure a cant of a voice coil transducer, the technique including measuring a capacitance between one portion of the voice coil transducer with respect to another portion of the voice coil transducer over a range of movement of the voice coil during operation.
Owner:TYMPHANY HK

Self-heating disk drive

Disclosed is a self-heating disk drive that comprises a voice coil motor (VCM), a spindle motor, and a temperature sensor. The VCM includes a VCM coil and the VCM is configured to move an actuator having a head attached to a distal end of the actuator. The spindle motor includes a plurality of spindle coils to spin a disk of the disk drive. The temperature sensor is used to read an internal temperature of the disk drive. Circuitry is configured to: command the application of current to the VCM coil without loading the head onto the disk and to the spindle coils of the spindle motor in a manner so as not to spin the disk; and, if the internal temperature reading reaches a pre-determined spindle temperature, the spindle motor is allowed to spin-up the disk.
Owner:WESTERN DIGITAL TECH INC

Device for rotatably positioning a camera or similar article about two orthogonal axes

A positioning device is provided for rotatably positioning a camera or other article about orthogonal rotational axes. The positioning device includes a carriage supported for rotation about a horizontal axis by a yoke. The yoke is in turn rotatably coupled to a base assembly for rotation of the yoke about a vertical axis. Rotation of the camera about the horizontal and vertical axes is respectively effected by first and second voice coil actuators, each comprising a pair of magnets and at least one coil to which current is supplied. The amplitude and direction of the current supplied to the coil determines the speed and direction of rotation of the camera. The second voice coil actuator preferably includes a coil assembly comprising two opposed coils. This design overcomes the angular range limitations associated with prior art voice coil actuators and enables rotation of the camera about an extended angular range. The device can be advantageously utilized for adjustment of the pan and tilt angles of a video camera in a conferencing system.
Owner:POLYCOM INC

Speaker device and mobile phone

A speaker device includes: a magnetic circuit which includes two magnetic gaps; a diaphragm which is arranged at a position passing through at least the two magnetic gaps and includes a recessed part extending in a direction substantially orthogonal with respect to an extending direction of a magnetic flux in the magnetic gaps; and a voice coil, formed into an annular shape, which includes a first parallel part extending in one direction and a second parallel part extending in a direction in parallel with the first parallel part and opposite to the first parallel part with a constant space. Particularly, the first parallel part and the second parallel part are arranged in a direction in parallel with an extending direction of the recessed part, respectively, and the first parallel part and the second parallel part are arranged in the recessed part to be positioned in the two magnetic gaps, respectively.
Owner:PIONEER CORP +1

Calibration of an actuator

Control system for devices such as an audio reproduction system, an actuator device, an electromechanical device and a telephony device. The system includes control circuitry which receives an input signal and a signal indicative of a position of a portion of the controlled apparatus. The control circuit provides an output signal to the controlled apparatus to affect an operation of the controlled apparatus. The output signal provides control of the apparatus to compensate for one or more of: motor factor; spring factor; back electromotive force; and impedance of a coil in a driver of the controlled apparatus. The signal indicative of position is derived by one or more position indicator techniques such as an infrared LED and PIN diode combination, position dependent capacitance of one portion of the controlled apparatus with respect to another portion of the controlled apparatus, and impedance of a coil in the controlled apparatus. The control circuitry is configurable to control transconductance and / or transduction of the system being controlled. A technique is disclosed to detect and measure a cant of a voice coil transducer, the technique including measuring a capacitance between one portion of the voice coil transducer with respect to another portion of the voice coil transducer over a range of movement of the voice coil during operation.
Owner:TYMPHANY HK

Control system

Control system for devices such as an audio reproduction system, an actuator device, an electromechanical device and a telephony device. The system includes control circuitry which receives an input signal and a signal indicative of a position of a portion of the controlled apparatus. The control circuit provides an output signal to the controlled apparatus to affect an operation of the controlled apparatus. The output signal provides control of the apparatus to compensate for one or more of: motor factor; spring factor; back electromotive force; and impedance of a coil in a driver of the controlled apparatus. The signal indicative of position is derived by one or more position indicator techniques such as an infrared LED and PIN diode combination, position dependent capacitance of one portion of the controlled apparatus with respect to another portion of the controlled apparatus, and impedance of a coil in the controlled apparatus. The control circuitry is configurable to control transconductance and / or transduction of the system being controlled. A technique is disclosed to detect and measure a cant of a voice coil transducer, the technique including measuring a capacitance between one portion of the voice coil transducer with respect to another portion of the voice coil transducer over a range of movement of the voice coil during operation.
Owner:TYMPHANY HK

Voice coil motor array module

A voice coil motor array module includes a carrier frame defining a plurality of receiving spaces and a plurality of magnet-mounting spaces disposed in pairs and in symmetry around the receiving spaces. Any two adjacent receiving spaces have only one magnet-mounting space therebetween. A plurality of magnetic components are respectively disposed in the magnet-mounting spaces. Each magnet-mounting space receives only one magnetic component. The magnetic components surrounding a corresponding receiving space have same magnetic poles facing each other. A plurality of displacement components are respectively disposed in the receiving spaces. Each displacement component includes a lens carrier and a coil.
Owner:LITE ON ELECTRONICS (GUANGZHOU) LTD +1

Position detection of an actuator using infrared light

Control system for devices such as an audio reproduction system, an actuator device, an electromechanical device and a telephony device. The system includes control circuitry which receives an input signal and a signal indicative of a position of a portion of the controlled apparatus. The control circuit provides an output signal to the controlled apparatus to affect an operation of the controlled apparatus. The output signal provides control of the apparatus to compensate for one or more of: motor factor; spring factor; back electromotive force; and impedance of a coil in a driver of the controlled apparatus. The signal indicative of position is derived by one or more position indicator techniques such as an infrared LED and PIN diode combination, position dependent capacitance of one portion of the controlled apparatus with respect to another portion of the controlled apparatus, and impedance of a coil in the controlled apparatus. The control circuitry is configurable to control transconductance and / or transduction of the system being controlled. A technique is disclosed to detect and measure a cant of a voice coil transducer, the technique including measuring a capacitance between one portion of the voice coil transducer with respect to another portion of the voice coil transducer over a range of movement of the voice coil during operation.
Owner:TYMPHANY HK

Disk drive computing repeatable run out while actuator arm is pressed against crash stop

A disk drive is disclosed comprising a voice coil motor (VCM) for rotating an actuator arm about a pivot in order to actuate a head over a disk. The disk is rotated by a spindle motor, and a feed-forward compensation value is computed that compensate for a non-centric alignment of the disk with respect to the spindle motor. During a calibration mode, the VCM is controlled to press the actuator arm against a crash stop, and the feed-forward compensation value is computed in response to a position error signal (PES). The PES is generated in response to embedded servo sectors recorded on the disk, wherein each embedded servo sector comprises a track address for coarse alignment and servo bursts for fine alignment.
Owner:WESTERN DIGITAL TECH INC

Speaker system for musical instruments

A speaker system for a musical instrument that detects the displacement of a voice coil of a speaker and provides feedback processing. The speaker system has a preamp that alters the frequency characteristics of the an electrical signal that has been input to an input terminal, and a power amplifier that amplifies the electrical signal. A speaker is driven by the power amplifier and a feedback unit detects the displacement of the speaker and provides a feedback signal to the power amplifier. The power amplifier amplifies the electrical signal in conformance with the output of the preamp and the feedback signal.
Owner:ROLAND CORP

Disk drive modifying estimated seek times for a rotational position optimization algorithm based on change in estimated seek time parameter

A disk drive is disclosed comprising a disk, a head, and a voice coil motor (VCM) for actuating the head over the disk. The disk drive executes a rotational position optimization (RPO) algorithm to select a next command to execute relative to an estimated seek time computed for each command in a command queue. A seek time parameter is estimated and a seek time delta computed in response to the estimated seek time parameter. The seek time delta is added to a nominal estimated seek time to generate a modified estimated seek time for each command in the command queue, thereby optimizing the RPO algorithm.
Owner:WESTERN DIGITAL TECH INC

Speaker device and mobile phone

A speaker device includes a magnetic circuit which includes a magnetic gap, a diaphragm which has a recessed part arranged in the magnetic gap and extending in a direction substantially orthogonal with respect to an extending direction of a magnetic flux in the magnetic gap, and a voice coil which is formed into an annular shape and has a first parallel part extending in one direction and a second parallel part extending in a direction in parallel with the first parallel part and opposite to the first parallel part with a constant space. Particularly, the first parallel part and the second parallel part are arranged in a direction in parallel with an extending direction of the recessed part, respectively. The first parallel part is arranged in the recessed part to be positioned in the magnetic gap, and the second parallel part is positioned above the recessed part.
Owner:PIONEER CORP +1

Process for position indication

Control system for devices such as an audio reproduction system, an actuator device, an electromechanical device and a telephony device. The system includes control circuitry which receives an input signal and a signal indicative of a position of a portion of the controlled apparatus. The control circuit provides an output signal to the controlled apparatus to affect an operation of the controlled apparatus. The output signal provides control of the apparatus to compensate for one or more of: motor factor; spring factor; back electromotive force; and impedance of a coil in a driver of the controlled apparatus. The signal indicative of position is derived by one or more position indicator techniques such as an infrared LED and PIN diode combination, position dependent capacitance of one portion of the controlled apparatus with respect to another portion of the controlled apparatus, and impedance of a coil in the controlled apparatus. The control circuitry is configurable to control transconductance and / or transduction of the system being controlled. A technique is disclosed to detect and measure a cant of a voice coil transducer, the technique including measuring a capacitance between one portion of the voice coil transducer with respect to another portion of the voice coil transducer over a range of movement of the voice coil during operation.
Owner:TYMPHANY HK

Macro-micro driven bidimensional integrated micro positioning platform

The invention provides a macro-micro driven bidimensional integrated micro positioning platform, which is characterized by including a base, a flexible platform body, two voice coil motors, four piezoelectric ceramic actuators, two displacement sensors and a controller, wherein the flexible platform body is fixed on the base; the two voice coil motors are connected with the flexible platform body; and the controller is in signal connection with the two voice coil motors, the four piezoelectric ceramic actuators and the two displacement sensors. The macro-micro driven bidimensional integrated micro positioning platform adopts a parallel decoupling totally flexible mechanism, and has the advantages of a parallel mechanism, a flexible mechanism and a decoupling mechanism; a macro-motion platform and a micro-motion platform are integrally designed; the same piece of material can be adopted to manufacture the macro-micro driven bidimensional integrated micro positioning platform integrally, and the manufacture is simple and convenient; and the motion decoupling design is applied to the macro-motion platform and the micro-motion platform, so that the motion control is facilitated and the positioning accuracy is improved.
Owner:UNIVERSITY OF MACAU

Method of modifying dynamics of a system

Control system for devices such as an audio reproduction system, an actuator device, an electromechanical device and a telephony device. The system includes control circuitry which receives an input signal and a signal indicative of a position of a portion of the controlled apparatus. The control circuit provides an output signal to the controlled apparatus to affect an operation of the controlled apparatus. The output signal provides control of the apparatus to compensate for one or more of: motor factor; spring factor; back electromotive force; and impedance of a coil in a driver of the controlled apparatus. The signal indicative of position is derived by one or more position indicator techniques such as an infrared LED and PIN diode combination, position dependent capacitance of one portion of the controlled apparatus with respect to another portion of the controlled apparatus, and impedance of a coil in the controlled apparatus. The control circuitry is configurable to control transconductance and / or transduction of the system being controlled. A technique is disclosed to detect and measure a cant of a voice coil transducer, the technique including measuring a capacitance between one portion of the voice coil transducer with respect to another portion of the voice coil transducer over a range of movement of the voice coil during operation. COMPUTER PROGRAM LISTING APPENDIX
Owner:TYMPHANY HK

Auto-focusing device with voice coil motor for position feedback and method for using same

An auto-focusing device with voice coil motor for position feedback comprises a lens holder, a sensor holder, a permanent magnet set, a yoke and a base. The lens holder holds a lens barrel and is wound around with at least two coils wound in opposite directions. The sensor holder holds an image sensor. The permanent magnet set includes at least two permanent magnets stacked together with opposing poles to form a multi-pole permanent magnet set. The permanent magnet set is furnished on the periphery of lens holder and corresponds to the two coils on lens holder. The permanent magnet set is disposed on the yoke to form a close-loop magnetism so as to increase the density of magnetic lines and the efficiency of magnetic force, save power consumption, and extend the service life of device.
Owner:POWERGATE OPTICAL INC

Fully integrated amplified loudspeaker

A fully integrated, low cost, amplified electro-acoustic loudspeaker is disclosed in which an amplifier circuit (30, 130, 230, 330, 930, 1030), radio-frequency receiver amplifier circuit (430, 530), optical receiver amplifier circuit (630, 730), or network based amplifier circuit (830) is directly mounted on the loudspeaker's magnetic assembly (105, 505, 705, 805), contained within the loudspeaker's moving assembly (20, 29, 629, 42, 45, 50, 65), or a combination thereof. The amplified loudspeaker's magnetic assembly (5, 105, 405, 505, 705, 805, 905, 1005) is utilized as an electro-magnetic interference shield and / or a heat dissipating element for the attached electronic circuitry. In selected embodiments of the amplified loudspeaker system, the former (42) containing voice coil (45) is additionally utilized for convection cooling of the amplifier circuit (30, 230) or receiver / amplifier circuit combination (430, 630).
Owner:BILAN FRANK ALBERT +1

Method of measuring a cant of an actuator

Control system for devices such as an audio reproduction system, an actuator device, an electromechanical device and a telephony device. The system includes control circuitry which receives an input signal and a signal indicative of a position of a portion of the controlled apparatus. The control circuit provides an output signal to the controlled apparatus to affect an operation of the controlled apparatus. The output signal provides control of the apparatus to compensate for one or more of: motor factor; spring factor; back electromotive force; and impedance of a coil in a driver of the controlled apparatus. The signal indicative of position is derived by one or more position indicator techniques such as an infrared LED and PIN diode combination, position dependent capacitance of one portion of the controlled apparatus with respect to another portion of the controlled apparatus, and impedance of a coil in the controlled apparatus. The control circuitry is configurable to control transconductance and / or transduction of the system being controlled. A technique is disclosed to detect and measure a cant of a voice coil transducer, the technique including measuring a capacitance between one portion of the voice coil transducer with respect to another portion of the voice coil transducer over a range of movement of the voice coil during operation.
Owner:TYMPHANY HK

Disk drive comprising a pulse width modulated demand limit circuit for enhancing power management during spin-down

A disk drive is disclosed comprising a head, a disk and a spindle motor for rotating the disk. An internal supply voltage is generated from a back EMF (BEMF) voltage across the windings of the spindle motor. The internal supply voltage is applied to a voice coil motor for use in parking the head during a spin-down mode. The internal supply voltage is compared to a threshold in order to activate a demand limit control signal. A periodic signal periodically disconnects the internal supply voltage from the VCM while the demand limit control signal is active.
Owner:WESTERN DIGITAL TECH INC

Servo writing a disk drive by writing spiral tracks using a mechanical position sensor

A disk drive is disclosed including a disk, an actuator arm, a head attached to a distal end of the actuator arm, a mechanical position sensor operable to generate a position signal representing a position of the head relative to the disk, and a voice coil motor for rotating the actuator arm about a pivot. The disk is rotated at a predetermined velocity, a control signal is generated in response to the position signal generated by the mechanical position sensor, and the control signal is applied to the voice coil motor in order to seek the head radially over the disk while writing a spiral track to the disk. The spiral track is then processed to maintain the head along a servo track while writing product servo sectors along the servo track.
Owner:WESTERN DIGITAL TECH INC

Disk drive pulse width modulating a voice coil motor using model reference current feedback

A disk drive is disclosed comprising a voice coil motor (VCM) driven in a PWM mode using model reference current feedback. The PWM circuitry and VCM form a plant transfer function which varies with changes to the plant characteristics, such as the resistance of the voice coil fluctuating with temperature drift. A plant model having a model transfer function generates an estimated state of the VCM in response to a detected current flowing through the voice coil. A correction block, responsive to the detected current, adjusts PWM timing signals so that the plant transfer function substantially matches the model transfer function.
Owner:WESTERN DIGITAL TECH INC

Disk drive monitoring a supply current to protect motor driver circuits

A disk drive is disclosed comprising a spindle motor for rotating a disk and a voice coil motor (VCM) for actuating a head over the disk. The spindle motor comprises a plurality of windings, and the VCM comprises a voice coil. If the current flowing from a supply voltage exceeds a threshold, the windings are disconnected from the supply voltage, the voice coil is disconnected from the supply voltage, and the first and second ends of the voice coil are connected to ground.
Owner:WESTERN DIGITAL TECH INC

Disk drive controlling a voice coil motor during an emergency unload

A disk drive is disclosed including a disk, a spindle motor operable to rotate the disk, a head, and a voice coil motor (VCM) operable to actuate the head over the disk, wherein the VCM comprises a voice coil. The disk drive further comprises a capacitor, and a back electromotive force (BEMF) voltage generator operable to generate a BEMF voltage from the spindle motor. The disk drive further comprises switching circuitry operable to connect the voice coil to the capacitor while accelerating the VCM, and to disconnect the voice coil from the capacitor and connect the voice coil to the BEMF voltage while decelerating the VCM.
Owner:WESTERN DIGITAL TECH INC

Magnetic data storage fixed hard disk drive using stationary microhead array chips in place of flying-heads and rotary voice-coil actuators

A magnetic data storage fixed hard disk drive using stationary Microhead Array Chips in place of conventional Flying-Heads and Rotary Voice-Coil Actuators or other Servo-Tracking mechanisms. Every Microhead Array Chip has a minimum of one thousand or maximum of four billion individual and addressable microhead read and write data-transducers built into it. The hard disk drive unit assembly that uses the Microhead Array Chip approach will have within its assembly as few as two or as many as twenty-eight installed Microhead Array Chips. The Microhead Array Chip hard disk drive unit assemblies will have at least one storage disk-platter with two disk-platter data-surfaces containing a multiplicity of concentric data-tracks that rotates at a substantially constant angular velocity. While Microhead Array Chips are made stationary by specially designed circuit boards, that positions a Microhead Array Chip over each of two data-surfaces of every disk-platter within the hard disk drive assembly. The total number of microheads within a stationary positioned Microhead Array Chip's Microhead Array is what determines the total number of available tracks on and across a data-platter's data-surface (i.e., 65,000 microheads would equal 65,000 cylinder / tracks).
Owner:OPTICAL STORAGE DEVICES

Disk drive employing a velocity profile and back EMF feedback to control a voice coil motor

InactiveUS7068463B1Reduce maximum latching force of magnetDriving/moving recording headsRecord information storageDriving currentElectric machine
A disk drive is disclosed comprising a disk having a plurality of tracks, an actuator arm, a head connected to a distal end of the actuator arm, and a voice coil motor (VCM) for rotating the actuator arm about a pivot to actuate the head over the disk. A driving current is applied to the VCM to control the motion of the actuator arm. A back EMF voltage generated by the VCM is detected, and a velocity of the VCM is estimated in response to the back EMF voltage. The estimated VCM velocity is compared to a target velocity in a velocity profile, wherein the velocity profile comprises at least an acceleration component and a coast component. The driving current is adjusted in response to the comparison so that the velocity of the VCM substantially follows the velocity profile.
Owner:WESTERN DIGITAL TECH INC

Disk drive updating estimate of voice coil resistance to account for resistance change prior to unload operation

A disk drive is disclosed comprising a disk and a head actuated over the disk by a voice coil motor (VCM) comprising a voice coil, wherein the VCM is controlled by a VCM control loop comprising an IR voltage detector. The IR voltage detector is updated by measuring a first back EMF voltage of the voice coil, and after measuring the first back EMF voltage, applying a first control current to the voice coil for a first interval and applying a second control current to the voice coil for a second interval. After the second interval, a second back EMF voltage is measured, and a delta voltage is computed relative to a difference between the first back EMF voltage and the second back EMF voltage. The IR voltage detector is adjusted in response to the delta voltage and at least one of the first and second control currents.
Owner:WESTERN DIGITAL TECH INC
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