Abstract: A disk drive power manager that compares energy usage with a predetermined profile to select one of several reduced-power operating modes. An energy usage register is updated at regular intervals according to the energy used during each time interval. An attenuated average energy usage value is obtained by attenuating the energy usage measures over time and integrating the results. The average energy level is compared with several predetermined energy threshold profiles to select a full- or reduced-power operating mode. Operating mode selection automatically adapts to the usage pattern to optimally balance power consumption with operational accessibility.

Abstract: A system for predicting the failure of a storage unit, such as a disk drive. In a most general sense, the inventive system includes a first mechanism (20, 22, 24) for moving an element (16) over a surface (12) which is moving relative to the element (16). The first mechanism includes an arm (18, 20) for supporting the element (16) over the surface (12) and a motor (24) connected to the arm (18, 20). A position error detector (42) is included for detecting a change in torque applied to the motor (24) due to friction between the element (16) and the surface (12). The position error detector (42) provides a signal in response to changes in torque which is processed to predict a head disk interaction or failure of the storage system. In a particular embodiment, the position error detector (42) senses a change in a lateral force applied to the element (12) in response to a change in friction between the surface and the element.

Abstract: A disk drive power manager that compares energy usage with a predetermined profile to select one of several reduced-power operating modes. An energy usage register is updated at regular intervals according to the energy used during each time interval. An attenuated average energy usage value is obtained by attenuating the energy usage measures over time and integrating the results. The average energy level is compared with several predetermined energy threshold profiles to select a full- or reduced-power operating mode. Operating mode selection automatically adapts to the usage pattern to optimally balance power consumption with operational accessibility.

Abstract: A disk drive power manager that compares energy usage with a predetermined profile to select one of several reduced-power operating modes. An energy usage register is updated at regular intervals according to the energy used during each time interval. An attenuated average energy usage value is obtained by attenuating the energy usage measures over time and integrating the results. The average energy level is compared with several predetermined energy threshold profiles to select a full- or reduced-power operating mode. Operating mode selection automatically adapts to the usage pattern to optimally balance power consumption with operational accessibility.

Abstract: To reduce disk drive power consumption, a reduced disk rotational velocity idle mode is used wherein in-situ components of the drive calibrate the landing (or take-off) speed of each head/disk combination and establish a transition speed incrementally above the highest landing speed to assure that the heads both fly above the confronting disk surfaces and avoid substantially all the asperities projecting from the disk surfaces. This can be accomplished using digital harmonic ratio flyheight (HRF) measurement techniques. This system optimizes the power savings to the characteristics of the particular drive. The power saving can be imposed in stages, initially to maintain the capability of quick return to operating conditions and a final stage that realizes maximum power savings. The transition speed is recalibrated periodically, which enables monitoring of the device for degradation or future imminent failure as sequential transition speeds change.

Abstract: The invention produces and maintains clearance and glide test results for a disk file, stores these results, and monitors head clearance and disk asperities over the useful life of the file using native disk file electronics. The disk file includes a predictive failure analysis component which utilizes clearance and glide test results to predict impending failure of a disk in the disk file.

Abstract: Amplitude information is derived from a periodic waveform by digitally sampling the periodic waveform, filtering a digital harmonic signal out of the digital sample sequence of the periodic waveform, and computing the root mean square of the digital Mth harmonic signal over a predetermined number of successive samplings of the periodic waveform. The digital sampling is done at a rate such that there will be an integer number of samples "L" over the period of the first harmonic component of the digital sample sequence of the waveform signal. The root mean square value computation is simplified by selecting the sampling window width N and the harmonic M so that there is a predetermined relationship to a critical sampling number L given by the expression, L=(4MN)/(2j+1) where j=0, 1, 2, . . . . As long as this relationship is satisfied, the RMS value can be computed by summing the absolute value of selected digital amplitude values of the selected harmonic component of the digitized signal.

Abstract: Apparatus and method of even harmonic distortion compensation are provided for digital data detection in a disk file. The disk file includes a magneto-resistive (MR) head or other magnetic transducer head and an analog-to-digital converter (ADC) for providing a sampled readback signal. An even harmonic filter is coupled to the ADC for providing a filtered readback signal having only even harmonic components. An adder subtracts the filtered readback signal from the sampled readback signal for providing a compensated output signal. The compensated output signal is applied to a digital channel of the disk file.

Abstract: A method and apparatus for minimizing the effects of non-stationary high-energy noise sources in magnetic data storage channel through the use of an oversampling and post-sampling filtering anti-aliasing procedure. The initial analog data is sampled at a rate sufficiently above the Nyquist rate to avoid aliasing. The high-frequency sampling stream is then digitally filtered to produce a lower-rate digital data stream having a reduced Nyquist rate introduced by the post-sampling digital filter. Because the anti-aliasing post-sampling filter is digital, no phase distortion is introduced in the readback data signal. Because the post-sampling digital filter lowers the Nyquist rate, late digital processing and decoding is accomplished without aliasing at a data rate below the initial Nyquist rate. High-energy noise pulses are preserved without smearing and can be simply removed by the usual error-correction method.

Abstract: A bias current servo loop for a magneto-resistive recording head detects distortion in the read signal from the MR head, and adjusts the operating point for the head to minimize the distortion. The distortion is detected by monitoring the second harmonic of a digitized sample of the read signal. A running average of the digitized amplitude of the second harmonic is generated by a digital bandpass filter. The root mean square of the running average of the digitized amplitude of the second harmonic is estimated. The estimated RMS value is compared against a reference value indicative of minimum distortion and the difference between the estimated RMS value and the reference value is used to adjust the bias current.

Abstract: A method and system includes digitally linearizing a digital output signal originating from a magnetoresistive sensor by detecting the digital output signal originating from the magnetoresistive sensor. A linearization factor is then correlated to the digital output signal. Then, the digital output signal is modified the linearization factor to linearize the digital output signal.

Abstract: A method and apparatus are provided for measuring flying height changes of a transducer head relative to a disk surface of a rotating disk in a disk file. A predetermined pattern is written on at least one predetermined region of the disk file. The predetermined region is normally not rewritten during operation of the disk file. At least one readback signal is sensed from at least one predetermined region of the disk surface. A plurality of sample values are identified corresponding to each readback signal. A change in the flying height is calculated utilizing the identified sample values. A frequency equalization number K can be utilized to calculate the magnitude and sign of the flying height change. Alternatively, real-time digital analysis of a predetermined pattern written on at least one predetermined region of the disk surface can be utilized to calculate the magnitude and sign of the flying height change.

Abstract: In an ink jet printing system wherein a drop generator emits ink droplets for printing on a recording media, deleterious ink mist or ink dust formed as a result of ink droplets impacting on the media is collected by a collecting container disposed relative to the zone whereat ink droplets contact the media. A vacuum system is coupled to the container and extracts ink mist which is returned to the ink supply system for reuse. Airborne contamination, to components such as the drop generator, charge electrodes and deflection electrodes, are prevented by encasing the components in a pressurized box.

Abstract: Disclosed is a droplet aspirator suitable for use with a multinozzle ink jet printer. The aspirator includes a housing with a flow channel therein. The flow channel includes an exit section having a substantially planar geometry with a constant cross-sectional area extending from a point where ink droplets are ejected into the channel to a point where the droplets exit said channel, an entry section having a relatively large cross-sectional area and an intermediate section with reduced cross-sectional area interconnecting the entry section with the exit section.