| 摘要 |
PURPOSE:To reproduce or record a signal simultaneously or alternately from two surfaces by arranging a first identification information to identify the position of one information plane and a second identification information to identify the position of the other information plane both on a spiral or concentric track. CONSTITUTION:A recording carrier 1 has recording carriers 1a and 1b of the same format stuck together. A spiral guide track is divided into four sectors 2 per cycle of the carrier 1. The sectors 2 are each made up of an address signal area 3 preset at the head thereof and a recording area 4 for recording signals. The area 3 is provided to identify a radius-wise track position and a circumference-wise sector position. Thus, when reading heads, upper and lower, are provided on the carrier 1, a signal can be reproduced from two surfaces and recorded on both the surfaces as well with the carrier 1 rotating. |
