1. Field of the Invention
The present invention relates to the storage and retrieval of data on magnetic tape, and more particularly, to a tape drive for automatic insertion, registration and ejection of a tape cartridge of the type having dual hub driven reels and a tape access door on a forward end which pivots about an axis perpendicular to a rigid mount plate of the cartridge.
2. Description of the Related Art
Magnetic tape has long been used as a storage media for audio, video and computer information. Tape cartridges have been used extensively because they provide a convenient way to house and support a length of magnetic tape for engagement by a transducer in a tape drive while protecting the tape upon removal of the cartridge. Tape cartridges with dual reels are widely used because they eliminate the need to thread a leader outside the cartridge or utilize an endless loop single reel arrangement. Examples of dual reel tape cartridges that have been extensively commercialized are the Phillips cassette used for audio recording, the VHS cassette used for video recording, and the DC600 data cartridge used for back-up storage of computer data files stored on hard disk drives. The latter data cartridge is disclosed in U.S. Pat. No. 3,692,255 of Von Behren assigned to Minnesota Mining and Manufacturing Corporation.
An improved magnetic tape cartridge particularly well suited for high capacity computer data storage is disclosed in U.S. Pat. No. 5,294,072 of Don G. East, et al. assigned to International Business Machines Corporation. That cartridge includes dual hub driven reels which lock upon disengagement with drive clutch assemblies and a pivoting tape access door with a pseudo-head for improved tape tension control. This eliminates the need to fully rewind the tape before reading or writing data which delays access to data with cartridges such as those embodying the invention of the aforementioned U.S. Pat. No. 3,692,255.
It would be desirable to provide a tape drive that utilizes the improved magnetic tape cartridge of the aforementioned U.S. Pat. No. 5,294,072. Preferably such a tape drive should include an automatic loader mechanism for fast and reliable insertion, registration and ejection of the improved magnetic tape cartridge. The loader mechanism must also be capable of opening the tape access door and registering a transducer with the tape. It is critical that the loader mechanism accurately register the tape cartridge at unique datum locations to provide repeatability in reading and writing multi-track data recorded at high densities and to enable exchange of data between different drives. The automatic loader mechanism must not be unduly complex in order to minimize failures and reduce manufacturing costs. It must also preferably be small enough to fit within the industry standard and five and one-quarter inch form factor for peripheral storage devices. No prior art tape drive has heretofore been developed with a cartridge loader mechanism adapted to achieve these objectives with the improved magnetic tape cartridge of the aforementioned U.S. Pat. No. 5,294,072.