High-density magnetic tape recording by non-tracking method

Abstract

Conventional helical-scan magnetic recording requires precise head tracking, precise tape path and accurate servo control. We have developed a magnetic tape recording system based on a new concept, the ‘non-tracking method’, which requires less accuracy. By combining double density track scanning and data rearrangement through a memory device, all data can be reproduced in correct order without precise head tracking. When the track pitch is 9.8 μm, the non-tracking method expands the tolerance on head tracking to ±100 μm, while the head tracking tolerance of ±5 μm is needed in conventional recording. Using the non-tracking method, a newly developed rotary head drum loading system called ‘non-loading’ and also a newly developed metal-evaporated tape, we have developed an extremely high density digital audio tape recording system, including a stamp-sized tape cassette and a miniature digital audio recorder. Two hours stereo digital recording is achieved with the small cassette.