| 摘要 |
A thermomagnetic layer on a slave tape has a Curie temperature above which it loses, and below which it stores, an image. Such layer is heated above the Curie temperature just before such layer records an image. To compensate for image stretching in such layer by the heat, the lines in a raster scan on the mirror-master tape are lengthened relative to such lines on a master tape during an image transfer between the tapes. To accomplish this, a rotary member holding the mirror-master tape has a larger diameter than, and rotates at the same angular speed as, a rotary member holding the master tape. To inhibit the slave tape separation from the heater by water vaporization in the thermomagnetic layer, (1) the heater heats such layer while the slave tape moves in a direction opposite to its movement during the image transfer or (2) a microwave oven heats such layer. The slave tape length may be determined from (1) the capstan revolutions for a reference tape of a given length and for the full length of the slave tape or (2) the angular revolutions of the slave tape supply and take-up reels at successive time instants, and the radius of the slave tape supply and take-up reels without tape on such reels. A sufficiently long slave tape may then be wound on the supply reel through an angular revolution of the particular reel dependent upon the image length on the master tape.
|
