| 摘要 |
<p>PURPOSE:To obtain invariable optimum sound quality by allowing two heads to scane on the same track during after recording operation in the same position relation with recording operation. CONSTITUTION:During reproduction (Qs=0), pulse Pg from a pulse generating means 43 are passed through a shaping amplifier 91 and delayed through a delay circuit by time corresponding to width DELTAW/2 to be supplied to a comparing circuit 95 through a switch circuit 92. Control pulses Pr from a head 45 are supplied through a regenerative amplifier 96 to the comparing circuit 95, whose comparison output is supplied to a motor 4 through an amplifier 95. Therefore, heads 1A and 1B scan on tracks 2A and 2B so that the centers coincide with each other. For after recording, when a switch 31 is turned on, Qs=1 and a switch 92 is changed over to supply undelayed pulses Pg to the comparator 95, thereby allowing the heads 1A and 1B to scan on the centers of the tracks 2A and 2B after a specific time depending upon the response time of a servo circuit. Thus, invariably optimum sound quality is obtained.</p> |
