| 摘要 |
PURPOSE:To perform immediately recording and reproduction by resetting a reference pulse temporarily with a phase detection pulse when a rotating speed attains almost to a set speed and phase control is almost started. CONSTITUTION:For example, when a speed V0 different from the current cylinder rotating speed is supplied from a control part 9, the speed difference approximates to zero immediately, but a phase error remains. When the reference pulse phi is reset with a reset signal (r) generated from a phase detection pulse phi at time (t), the phase difference between the reference pulse phi0 and phase detection pulse phi becomes nearly zero. When the time up to the stabilization of the speed control over the cylinder 2 is known, a signal delayed through a timer, etc., by a specific time after the generation of a speed variation command is supplied from the control part 9 to a reset signal generating part 12 as a reset enabling signal (e). Consequently, the response of the phase control is speeded up greatly. |
