| 摘要 |
PURPOSE:To improve the S/N of a section with overlapped recording, by increasing a recording current at this section, in recording other new video signals on the way of a recorded magnetic tape. CONSTITUTION:A timing output regulating the start and end of recording as shown in figure (a) is obtained as an output of an FF28 by a switch 27. A counter 33 cleared at the trailing of an output signal (c) at a delay time T2 counts clock signals applied to a terminal 35 sequentially and when the count value is a set value or below, a high level output (e) is produced. A period T3 where the output (e) goes to high level is set to a time or over in driving the tape length from the position of an erasing head to a point where a rotary head and the magnetic tape are detached. The output (e) is applied to a gain control amplifier 25, the gain is increased by the time T3 to increase the recording current. Thus, a recording current larger than the optimum recording current is obtained for the period T3 in the amplifier 25. Then, the S/N of the section is improved by increasing the recording current for the section of duplicated recording. |
