HIGH-DENSITY MAGNETIC-TAPE RECORDING BY NONTRACKING METHOD

Conventional helical-scan magnetic recording requires precise head tra cking, precise tape path and accurate servo control. We have developed a magnetic tape recording system based on a new concept, the 'non-tra cking method', which requires less accuracy. By combining double densi ty 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 mum, the non-tracking method expands the tolerance on head tracking to +/- 100 mum, while the head tracking tol erance of +/- 5 mum is needed in conventional recording. Using the non -tracking method, a newly developed rotary head drum loading system ca lled 'non-loading' and also a newly developed metal-evaporated tape, w e have developed an extremely high density digital audio tape recordin g system, including a stamp-sized tape cassette and a miniature digita l audio recorder. Two hours stereo digital recording is achieved with the small cassette.