Texas Instruments Corporation

Mark W Heaton

Arthur Monroe Turner

Andrew Steven Dewa

David Patrick Magee

Michael K Masten

Tsen-Hwang Lin

John Walter Orcutt

Kurt Peter Wachtler

Philip A Congdon

Michael Thomas DiRenzo

Eric Gregory Oettinger

Mark David Heminger

Peter Joseph Maimone

Michael T Direnzo

Philip A Roden

Carter Bruce Simpson

Mark A Avery

Carter B Simpson

A pivoting device such as a MEMS mirror provides improved coupling between a permanent magnet on the device and an adjacent electrical coil that may provide a drive force or position sensing. The improved coupling is obtained by forming a cavity in the coil structure. The cavity receives the permanent magnet such that the spacing between the magnet and the electrical windings or coil is at a minimum.

Torsional hinged device with improved coupling between a magnet mounted to said device and an electrical coil

Apparatus and methods for removing jitter and stabilizing the feed back system of a torsional hinged device with minimal changes to the system. The stabilization is accomplished by spatially isolating the pivoting mirror structure from all drive, support and packaging structures to reduce air drag. The mirror structures may be further stabilized by tailoring the drive mechanism and the position of the mechanism to produce substantially pure rotational drive torque on the mirror.

Reduction of open loop jitter and control loop stabilization of a torsional hinged device by structural optimization

Apparatus and methods for removing jitter and stabilizing the feed back system of a torsional hinged device with minimal changes to the system. The stabilization is accomplished by introducing a selected amount of lateral motion (in addition to the rotational motion) by creating asymmetry in the oscillating device or the drive torque applied to the device.

Stabilization of closed loop operation of a torsional hinged device

Devices being controlled electronically via physical manipulation often display a resonance. In many circumstances, the frequency range of operation is not close to the resonance frequency. In these cases, the resonance can be removed through the use of simple compensation techniques such as filters. However, when the resonance frequency is close to the frequency range of operation and when the resonance frequency can change depending on temperature, time, and physical position of the device, simple compensation techniques cannot be used. The present invention presents a non-mechanical technique for providing compensation for devices with a shifting resonance. The non-mechanical technique allows for the compensation to be performed via computation.

High performance controller for shifting resonance in micro-electro-mechanical systems (MEMS) devices

A magnetic drive for providing pivotal motion to a functional surface, such as a mirror. The magnetic drive may be used to drive any torsional hinged device, but is particularly suitable for driving a torsional hinged mirror. According to a first embodiment, a dual axis functional surface uses a first pair of torsional hinges to provide primary movement to the functional surface and a second pair of torsional hinges provides movement orthogonal to the primary movement to allow positioning in two directions. The mass and movement of inertia of the functional surface is reduced by relocating permanent magnet sets to the axis of rotation. The reduced mass and movement of inertia results in a stiff robust hinge having a resonant frequency above about 120 Hz.

Pivoting mirror with improved magnetic drive

A system and method for providing a resonant beam sweep about a first axis. A mirror or reflective surface supported by a first pair of torsional hinges is driven into resonant oscillations about the first axis by inertially coupling energy through the first pair of torsional hinges. A light source reflects a beam of light from the mirror such that the oscillating mirror produces a beam sweep across a target area. The resonant beam sweep is moved orthogonally on the target area by a gimbals portion of the mirror pivoting about a second axis according to one embodiment. A second independent mirror provides the orthogonal movement according to a second embodiment.

Resonant scanning mirror with inertially coupled activation

A position sensor for a pivoting platform which has a first portion that flexes when the platform pivots and a second portion of the platform that is rigid, utilizes a piezoresistive element on the first portion of the platform. A connecting terminal for the piezoresistive element is on the second portion and thus not subject to the flexing stresses. The platform can have two symmetrical arms as the flexing portion, and a pair of piezoresistive elements can be formed on each of the arms in order to double the output voltage changes with changes in these positions of the platform. A temperature compensating piezoresistive element can be formed on the rigid portion of the platform and connected to the piezoresistive element or elements. The piezoresistive elements can be formed directly on the portions of the platform.

Position sensor for a pivoting platform

System and method for establishing and maintaining resonant oscillations of a torsional hinged device such as a pivotally hinged mirror. The system and methods comprise a permanent magnet mounted to the pivoting mirror that interacts with an electromagnetic coil. The magnetic coil is periodically connected and disconnected from a DC power supply in response to a series of drive pulses having a timing and duration such that the magnetic forces generated by the interaction of the permanent magnet and the electromagnetic coil maintains resonant oscillations of the device.

Pulse drive of resonant MEMS devices

A system and method for providing resonant movement about a first axis. A functional surface supported by a first pair of torsional hinges is driven into resonant oscillations about the first axis by inertially coupling energy through the first pair of torsional hinges. The resonant movement may be moved orthogonally on the target area by a gimbals portion of the functional surface pivoting about a second axis according to one embodiment. The resonant oscillation of the functional surface is monitored to detect changes in frequency due to mass changes of the functional surface.

Resonant pivoting surface with inertially coupled activation

A pivoted platform has two flexible arms having rigid end zones which are attached by means of spacers to piezoelectric elements. The piezoelectric elements are made to deflect in opposite directions upon the application of the electrical signal to cause the platform to pivot. Applying voltages of the opposite polarity causes the platform to pivot in the opposite direction. A mirror may be attached to the platform to produce a scanning mirror for the vertical deflection of a television image.

Pivoting platform having a piezoelectric drive

A movable mirror device driven by a reluctance force motor is provided. A sheet of material has a mirror portion, a hinge portion, and a frame portion formed therein. The mirror portion is coupled to the frame portion via the hinge portion. The reluctance force motor is formed from a magnetic flux channeling circuit. A wire coiled about a portion of the magnetic circuit is used to induce a magnetic field through the magnetic circuit. Air gaps in the magnetic circuit provide attractive forces between portions of the magnetic circuit when a magnetic field is present in the magnetic circuit. The air gaps and the magnetic circuit are configured so that the magnetic attractive forces at the air gaps exert torque on the mirror portion about the hinge portion. When the hinge portion is twisted, it acts as a torsional spring biasing the mirror portion toward a neutral relaxed position.

Scanning MEMS mirror with reluctance force motor

This invention comprises an architecture for voltage mode control of a voice coil motor in a hard disk drive. In contrast to conventional current mode control, coil current is not sensed or measured, which simplifies the feedback design with less hardware required in the implementation. Common design methodologies for the square root velocity profile, linear velocity profile and regulator/estimator control system designs can be migrated from the current mode architecture to the voltage mode architecture.

Digital servo control system for a hard disc drive using a voice coil motor in voltage mode

A method of adjusting a MEMS mirror control system is provided to calibrate a MEMS mirror control system to a particular MEMS mirror in a fashion that optimizes MEMS mirror control loop performance. This calibration is implemented by measuring the gain and resonant frequency of the particular MEMS mirror, and adjusting one or more of the parameters used in the implementation of a PID controller, a state estimator, and a feed forward component used to perform seeks.

System identification to improve control of a micro-electro-mechanical mirror

A position sensor includes a stationary platform and a moveable platform. The position sensor further includes at least one beam coupling the moveable platform to the stationary platform. The at least one beam includes piezoresistive material that is positioned tolprovide an indication of a movement of the moveable platform relative to the stationary platform.

System and method for determining the position of a device

A read/write head assembly ( ) is provided for use in a mass storage device such as a hard disk. drive. The read/write head assembly ( ) is positioned on a suspension arm ( ) and includes a read/write head ( ) and a head lifter ( ). The head lifter ( ) positions the read/write head ( ) in a first position and a second position.

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Irving, TX, United States of America

Mark W Heaton