method for recording or reproduction of information on a magnetic intermediate forms) and intermediate forms and device for implementation of the procedure

摘要

1524187 Magnetic recording/playback EMI Ltd 2 Oct 1975 [16 Oct 1974] 44749/74 Heading G5R In a magnetic recording/playback arrangement using a "watermarked" recording medium, e.g. a tape which is formed with a layer of anisotropic particles which have their easy axes of magnetization in adjacent areas inclined in one of two different directions with respect to the direction of the length of the tape, the tape is driven in the direction of its length and a read/ record head is orientated such that the axes of magnetization are equally inclined to the width direction of the head gap. The areas may have a long dimension inclined at 45 degrees to the tape length and the magnetic easy axes in adjacent areas can be at right angles to each other at 45 degrees to the width of gap 21. The watermarked tape does not affect recording/playback by the head and the watermark can be detected by a head with its gap width dispersed at an angle other than 90 degrees to the tape direction. The tape may be prepared as described in Specification 1,331,604.