Abstract: A method of writing servo patterns on a disc in an external servo track writer (“STW”) includes enclosing the disc and an actuator arm within an internal enclosure, while additionally enclosing the internal enclosure and the remainder of the STW by an outer cover. The internal enclosure is filled with a low-density gas prior to writing the servo patterns on the disc. Gas overflowing from the internal enclosure is contained by the outer cover which further retains the low-density gas once the internal enclosure is opened at the conclusion of the servo writing process. The low-density gas is then purged from the STW for recycling before the outer cover is opened and the disc is removed. The internal enclosure may comprise two separate components moveable between an open and closed position to allow for loading and removal of the disc from a spindle motor of the STW.

Abstract: A method of detecting a leak of low-density gas from an enclosure containing a rotating storage disc includes monitoring a signal which varies in response to variations in the concentration of the low-density gas in the enclosure. Additional quantities of the low-density gas are added to the enclosure when the monitored signal indicates that the concentration has dropped below a predetermined level. Monitoring the concentration of the low-density gas may include monitoring actual concentration levels of the gas using a pressure sensor located within the enclosure or monitoring disc mode vibration amplitudes using an accelerometer attached to the enclosure. Indirect monitoring of the vibration amplitudes may also be accomplished using sensors such as a laser Doppler vibrometer, a capacitance probe or the servo head position feedback circuitry found within a disc drive or a dedicated servo track writer.

Abstract: A method of writing servo patterns on a disc in an external servo track writer (“STW”) includes enclosing the disc and an actuator arm within an internal enclosure, while additionally enclosing the internal enclosure and the remainder of the STW by an outer cover. The internal enclosure is filled with a low-density gas prior to writing the servo patterns on the disc. Gas overflowing from the internal enclosure is contained by the outer cover which further retains the low-density gas once the internal enclosure is opened at the conclusion of the servo writing process. The low-density gas is then purged from the STW for recycling before the outer cover is opened and the disc is removed. The internal enclosure may comprise two separate components moveable between an open and closed position to allow for loading and removal of the disc from a spindle motor of the STW.

Abstract: A mechanical signature analysis system for analyzing frequencies and magnitudes of vibrations in an operating test disc drive includes a test data acquisition module connected to the test disc drive to acquire time domain test data and convert it into frequency domain test data, a typical disc drive data module having frequency domain data for a typical disc drive, and a failure analysis module having failure limits associated with the typical disc drive frequency domain data to determine whether the test data are within the failure limits. An output module displays failure analysis results.

Abstract: A contamination resistant probe attachment device attaches over an opening in a top cover of a disc drive to couple a testing probe to the interior of the disc drive. The attachment device has a base for surrounding and attaching around the opening in the top cover in the disc drive and a centrally located aperture for communicating with an upwardly extending flexible tube. The flexible tube having a first and second end, the first end attaching to the base and a second end defining an engagement opening throughwhich a disc drive testing probe is inserted.

Abstract: A method of writing servo patterns on a disc in a servo track writer includes sealing the STW to form an enclosed interior environment and then filling the STW with a low-density gas. Once the servo patterns are written to the disc, the low-density gas may be purged from the STW and recycled by directing the purged gas to a recovery system that separates the low-density gas from air. The disc may be preinstalled within a disc drive which in turn is loaded within the STW. Alternatively, the STW may comprise a multi-disc writer having a plurality of dedicated servo writing heads. The servo writer includes a cover having a sealable opening for loading either the disc drive in the STW or for loading a disc stack within the MDW.

Abstract: A method of detecting a leak of low-density gas from an enclosure containing a rotating storage disc includes monitoring a signal which varies in response to variations in the concentration of the low-density gas in the enclosure. Additional quantities of the low-density gas are added to the enclosure when the monitored signal indicates that the concentration has dropped below a predetermined level. Monitoring the concentration of the low-density gas may include monitoring actual concentration levels of the gas using a pressure sensor located within the enclosure or monitoring disc mode vibration amplitudes using an accelerometer attached to the enclosure. Indirect monitoring of the vibration amplitudes may also be accomplished using sensors such as a laser Doppler vibrometer, a capacitance probe or the servo head position feedback circuitry found within a disc drive or a dedicated servo track writer.

Abstract: A mechanical signature analysis system for analyzing frequencies and magnitudes of vibrations in an operating test disc drive includes a test data acquisition module connected to the test disc drive to acquire time domain test data and convert it into frequency domain test data, a typical disc drive data module having frequency domain data for a typical disc drive, and a failure analysis module having failure limits associated with the typical disc drive frequency domain data to determine whether the test data are within the failure limits. An output module displays failure analysis results.

Abstract: A contamination resistant probe attachment device attaches over an opening in a top cover of a disc drive to couple a testing probe to the interior of the disc drive. The attachment device has a base for surrounding and attaching around the opening in the top cover in the disc drive and a centrally located aperture for communicating with an upwardly extending flexible tube. The flexible tube having a first and second end, the first end attaching to the base and a second end defining an engagement opening throughwhich a disc drive testing probe is inserted.

Abstract: A servo track writer used for the writing of servo information to a head disc assembly, the servo track writer including a tuned damper as part of a pusher block assembly, the tuned damper reducing the effects of errors in the written servo information as a result of resonant frequencies induced in the pusher block assembly. The pusher block assembly mechanically advances an actuator of the head disc assembly, the actuator including a head which selectively magnetizes portions of a rotating disc of the head disc assembly to write the servo information. The tuned damper portion of the pusher block assembly comprises a dampening block having a selected mass and a dampening pad comprising a layer of compliant material, the dampening pad isolating the dampening block from the rest of the pusher block assembly. The desired resonant frequency response of the pusher block assembly is achieved through selection of the mass of the dampening block and the compliance of the dampening pad.