Abstract: A method and apparatus are provided to compensate for the runout that commonly occurs during the reading from or writing of information on the surface of a disk medium using a read/write head. The runout relates to the distance the head is located away from a disk track center during the rotation of the disk. To maintain the head in alignment with the track center during the complete revolution of the disk, position information is obtained. This position information is used with discrete fourier transform techniques to provide a representation of the disk runout. From this representation, a compensating signal can be generated to provide movement of the head that compensates for the runout and keeps the head positioned in alignment with the track center at all times during the disk rotation.

Abstract: An apparatus is provided for removing invalid read signal peaks which are detected during a disk read operation. In one embodiment, the apparatus converts the analog read-back signal from the disk into a pair of signals, a raw data signal being indicative of the signal peaks read from the disk and a raw polarity signal being indicative of the polarity of such peaks. The raw data signal is inputted to a phase lock loop, which outputs a strobe signal. The raw data signal and the raw polarity signal are made synchronous with the strobe signal in a reclocking circuit. The data and polarity signals outputted by the reclocking circuit are synchronously applied to a qualifying circuit, the output therefrom being free of invalid data.

Abstract: A method and apparatus are provided in an embedded servo system for controllably moving, using a linear motor, a carriage assembly and one or more accompanying heads relative to one or more disk surfaces. Each disk surface includes sectors for reading and writing information. Each disk surface also includes servo fields spaced between the read/write sectors. The servo fields have preset servo or position information for each of the tracks on the disk. The position information is in the form of Normal and Quadrature generated signals used to determine the exact position of the head when it is located between track centers. Using the determined position of the head and knowing a target position on the disk surface, the distance remaining to the target position is found. Using the value of the distance remaining to the target position, a head velocity can be determined and the proper amount of current can be supplied to the linear motor so that the head arrives at the target position in minimal time.

Abstract: An apparatus is provided for loading a head onto a spinning disk and unloading the head from the spinning disk so that contact between the head and the disk is essentially prevented. The apparatus includes a Whitney-size head joined to the flexure of a Whitney-type suspension arm. A triangular-shaped ramp is fixed to a face of the suspension arm for engagement with a stationary cam. The stationary cam is located along the path of movement of the head, suspension arm and flexure. The contact between the cam and ramp causes movement of the head relative to the disk. In the case of loading the head, this movement results in a desired approach of the head towards the disk and enhances loading of the head onto the disk.

Abstract: A way is provided for protecting disks used in a computer peripheral system from contamination while allowing for purging air flow through the system during operation. When no cartridge is in the system a seal is in sealing engagement around a hub in a housing of the system preventing contamination from contacting a disk in the system and preventing the clean air from leaking out of the housing. With the cartridge in the system, a seal is formed between the cartridge and the housing preventing contamination from entering into the system thus protecting disks in the system from contamination and at the same time opening passageways so that purging air may be passed through the system.