| 摘要 |
<p>PURPOSE:To attain a servo to make a sampling frequency into a frame frequency and a servo to make it into the (n)-fold frequency by switching and using one phase control means. CONSTITUTION:A first switching means 15 automatically selectively switches and outputs a frame synchronizing signal S1 and the output S2 of a multiplying means 3 by a switching signal S8 from a terminal 2. An output control means 17 switches the frequency-dividing signal S5 of a rotation detector 12 or a head switching signal S4 in accordance with the polarity of the signal S8 and outputs it to a second switching means 18. A normalizing means 19 normalizes the switching signal S8 with the frame synchronizing signal S1, switches outputs S13 and S14 of the means 17 through the means 18 and outputs them to a phase control means 16. The means 16 switches the action condition by the signal S8, and when the signal S1 is inputted, comparing is executed with a frame frequency and when the signal S2 is inputted, the comparing is executed with the (n)-fold frequency. Consequently, the servo of the frame frequency and the (n)-fold frequency can be executed only by the means 16.</p> |
