Western Digital Technologies, Inc.

University of California

Government of the United States of America, As Represented by the Secretary of Commerce

Erik Jesper Eklund

Andrei M Shkel

Robert P Ryan

Duc T Phan

Timothy A Ferris

Albert J Guerini

Alain Chahwan

John Edward Scura

John Kitching

Hien T Chu

Michael K Liebman

May Ching Kung

Elizabeth Ann Donley

Eleanor Hodby

A method of tuning a notch filter in a data storage device (DSD) including the notch filter and a shock detection system includes: adjusting pulse width modulator (PWM) frequency settings of a spindle drive signal; detecting a maximum noise level of an output signal of the shock detection system while adjusting the PWM frequency settings; and selecting a notch filter frequency corresponding to a PWM frequency setting at which the maximum noise level of the output signal of the shock detection system is detected.

Shock sensor resonance detection for notch filter tuning

A data storage device is disclosed comprising a head actuated over a disk, and a sensor configured to generate a sensor signal representing at least one of a shock and a thermal popping affecting the data storage device. The sensor signal is first filtered based on a first frequency range corresponding to the shock to generate a shock signal, and second filtered based on a second frequency range corresponding to the thermal popping to generate a pop signal, wherein the second frequency range is different from the first frequency range. The shock signal and the pop signal are individually processed, for example, to log a disturbance event, to abort a write operation, or to generate a feed-forward servo compensation signal.

Data storage device filtering sensor signal to optimize shock and thermal pop detection

A disk drive includes a disk drive base, a disk drive top cover, and a head actuator pivotably attached to the disk drive base. The disk drive base and the disk drive top cover together form a disk drive enclosure that encloses the head actuator. At least one read head is attached to the head actuator. A disk drive printed circuit board (PCB) is attached to the disk drive base outside the disk drive enclosure. A motion sensor is attached to the disk drive base outside the disk drive enclosure. The motion sensor is disposed between the disk drive PCB and the disk drive base. The first motion sensor is electrically connected to the disk drive PCB by a plurality of resilient conductive prongs that are preloaded between the disk drive PCB and the first motion sensor.

Shock sensor on an external surface of a disk drive base adjacent a disk drive printed circuit board

A disk drive is disclosed comprising a head actuated over a disk, and control circuitry including a shock detector. A shock threshold of the shock detector is initialized, and a first number of shock events is detected in response to the shock detector operating at the initial shock threshold. When the first number of shock events exceeds an upper event threshold, a control signal is adjusted in order to adjust a frequency spectrum of noise affecting the shock detector. After adjusting the control signal, a second number of shock events is detected in response to the shock detector operating at the initial shock threshold. When the second number of shock events exceeds the upper event threshold, the shock threshold is increased.

Disk drive adjusting noise spectrum to reduce resonance excitation of shock detector

A method for glass-blowing on a microscopic level includes the steps of defining a plurality of microholes in a wafer, disposing a sheet of thermally formable material onto the wafer covering the microholes, heating the sheet of thermally formable material until a predetermined degree of plasticity is achieved, applying self-induced fluidic pressure by expansion of the heated trapped gas in the microholes to the sheet of thermally formable material, while the sheet is still plastic, and simultaneously forming a plurality of blown micro-objects in the sheet on the wafer by means of continued application of pressure for a predetermined time.

Self-inflated micro-glass blowing

An accelerometer and a method of fabricating an integrated accelerometer comprises the steps of providing an SOI wafer with a selected resistivity to eliminate any need for additional doping of the SOI wafer, providing a single mask on the SOI wafer, and simultaneously defining all components of the accelerometer in the SOI wafer without using any pn-junctions to define any piezoresistive components and to provide the same resistivity of all components. The step of simultaneously defining all components of the accelerometer in the SOI wafer comprises defining all components of a linear or angular accelerometer.

Single-mask fabrication process for linear and angular piezoresistive accelerometers

An atomic magnetometer that simultaneously achieves high sensitivity, simple fabrication and small size. This design is based on a diverging (or converging) beam of light that passes through an alkali atom vapor cell and that contains a distribution of beam propagation vectors. The existence of more than one propagation direction permits longitudinal optical pumping of atomic system and simultaneous detection of the transverse atomic polarization. The design could be implemented with a micro machined alkali vapor cell and light from a single semiconductor laser. A small modification to the cell contents and excitation geometry allows for use as a gyroscope.

Growing community of inventors

Costa Mesa, CA, United States of America

Erik Jesper Eklund