Abstract: An apparatus for reducing head wear in a helical scan tape transport passes a flow of relatively clean, dry air through a transport housing without allowing the flow of air to flow directly across the rotary head assembly. Air from a fan positioned at a rear portion of the transport cools a power supply and creates a positive air pressure within the transport housing. The air is heated by the power supply before it passes through the transport housing, so that only relatively "dry" air reaches the rotary head assembly. The air is exhausted out the opening through which a tape is loaded. This arrangement substantially reduces the possibility of contaminants entering the transport housing. Additionally, the air cleans a magnetic recording tape on a tape cartridge as the tape is passes through the transport housing so that only relatively "clean" tape reaches the rotary head assembly.

Abstract: A cassette for a high performance tape drive is disclosed. A cassette shell having the same general external dimensions as an industry standard leader block tape cartridge (3480/3490) includes both a tape supply spool and a take-up spool. Two tape guides present a segment of tape to a cassette access port which can be closed by a sliding door to prevent contamination when the tape is not in use. A tape cleaning device and a spool locking device are incorporated into the cassette mechanism.

Abstract: A tape cartridge or other physical volume includes a housing configured to accommodate magnetic data storage media, such as a reel of magnetic tape. A magnetic field detector is coupled to the housing for indicating whether the housing has been exposed to a magnetic field of sufficient intensity to corrupt or bulk erase the magnetic media. In a first embodiment, the detector is implemented as a magnetic media element having a predefined pattern of magnetic domains recorded thereon. In a second embodiment, the detector is implemented with a magnetic film element having a predefined pattern of magnetic domains recorded thereon and a polarizing filter stacked on top of the magnetic film element to polarize light incident upon the magnetic film element. Based on the Kerr effect, light incident upon the magnetic domains will undergo a shift in polarization angle before being reflected back to the polarizing filter. Erasure or alteration of the magnetic domains will modify the polarization shift.

Abstract: For primary use in a storage and retrieval subsystem in a data processing system, a robotic transfer system acts to transfer selected electronic magnetic storage cartridges between their storage and transducing positions, typically between vertically stacked concentric tape storage holders and a selected tape drive. The robotic transfer system for handling tape cartridges includes two hands, each mounted on a separate vertical axis disposed at opposite ends of a balanced rotating horizontal axis, such that no tape cartridge is ever more than 90.degree. away from the nearest hand. The use of two hands also provides a redundant data retrieval capability without concentrating the weight of two hands at a single end of a revolving horizontal arm, thus reducing the moments generated by angular movement and providing for faster tape access time and greater long-term system reliability.

Abstract: The self sealing data storage element presents a uniform form factor data storage element that can be used to house any one of a plurality of types of tape media. The tape media is wound around a single reel contained within a housing of predefined external dimensions. The housing includes an opening in one corner thereof through which the tape media is extracted by an associated drive element. In order to enable the drive element to securely grasp the tape media, a leader block is affixed to the end of the tape media nearest the opening in the housing. In order to provide the self-sealing capability, a length of leader tape is provided between the leader block and tape media in order to completely encapsulate the tape media once it is wound around the reel contained within the housing. The leader block is of width at least as great as that as the tape media and preferably slightly larger in order to automatically compensate for any lack of uniformity in the winding of the tape media on the reel.

Abstract: A first signal to be stabilized in a magnetic record member is recorded via a head having a given maximal gap length and pole pieces of high saturation induction. After the first signal is recorded, the magnetic record member is surface erased for stabilizing the just recorded signal. In a preferred form, the surface erasing is performed by AC erasing via a transducer having a gap length less than said maximal gap length. The pole pieces of the erasing head need not have the high saturation induction of the first mentioned head. After such stabilization, signals can be easily recorded and recovered from the magnetic record member by using transducers with gap lengths less than such given maximal gap length and using the normal ferrite heads having a lower saturation induction than the first mentioned heads. The first signal can be advantageously employed as a position indicating signal in a magnetic record member, such as a storage disk or tape.

Abstract: An AC magnetic erase head having improved AC erase characteristics, the magnetic head being formed of two half core elements of a magnetic material, preferably ferrite, defining an irregular edged or jagged-edged gap, and including a non-magnetic substance, preferably glass, within the gap. The magnetic head is preferably produced by thermally etching ferrite magnetic material forming the half core elements by means of relatively prolonged heat soak at an elevated temperature.