| 摘要 |
PURPOSE:To form a drum used in different systems, by providing heads at intervals, which are determined on a basis of the ratio of the diameter of a rotary drum of one system to that of a drum of another system, for this rotary drum of one system and providing tape guides which give lead angles adapted to both systems. CONSTITUTION:When data of the VHS system is recorded in, for example, the two-head (A1 and B1) type beta system in case that rotary head drum diameters phiB and phiV of the beta system and the VHS system are 74.487mm. and 62mm. respectively, 180 deg.xP=149.82 deg. is true if phiV/phiB=P, and heads A11-A16 and B11- B16 are arranged at intervals of 149.82 150 deg. in the VHS system though intervals of heads are 180 deg. in the beta system. Heads A1 and A11 and heads B1 and A14 become combination heads. A lower rotary drum RD1 is provided with a tape guide G1 of the beta system, and an upper rotary drum RD2 is provided with a tape guide G2 of the VHS system. When the data of the beta system is recorded and reproduced in the two-head VHS system, 180 deg./P=216.18-220 deg. is true, and the processing is performed similarly. Thus, the drum is used in both systems. |
