| 摘要 |
PURPOSE:To record with two heads alternately, and to attain small-sized, by holding a diameter of a rotary drum of two-head helical scanning system or a rotary plate, in a specified relation with the diameter of a rotary drum of the conventional system. CONSTITUTION:Video heads H3, H4 having a gap with different azimuth angle are fitted to a rotary drum 12 closely with a prescribed interval. A magnetic tape 1 is wound on the drum 12 over about 300 deg. with poles 3, 4 and 13-15. The relation of D2 180/alphaXD1 is obtained, where D2 is a diameter of the drum 12, alpha is an effective winding angle of the tape 1, and D1 is a diameter of the conventional two-head type helical system. The picture information having the horizontal scanning period numbers equal to the horizontal period numbers reproduced from one track and a vertical synchronizing signal are recorded on the tape 1 having the angle alpha or the vicinity with the heads H3, H4 by taking about 1.5 revolution of the drum 12 as the period, to attain small-sized. |
