| 摘要 |
<p>PURPOSE: To attain a precise phase control and tracking by outputting a result to a control means when a count value coincides with a first and a second fixed values, and interrupting the control means when the count value coincides with a third fixed value. CONSTITUTION: A control means 10 outputs a first and a second fixed values and a third fixed value showing 50% duty. When a comparison means 40 compares the count value of a counter 20 with the third fixed value and both values coincide with each other, the means outputs this result to a gating means 50. By combining the output of the means 40 with the output of recording/reproducing terminal of the means 50 which is high only at the time of reproducing, the means 10 conducts the control of the reproducing system. On the other hand, a control head Hc picks up a control signal from a videotape, and supplies it to a second buffer 80 through a reproduction amplifier 90 and a second FF100. When the count value of the counter 20 approaches the first fixed value outputted from the means 10, the mans 40 recognizes the control signal of the means 10 as '1'. On the other hand, the count value approaches the second fixed value, the means comes to recognize the control signal as '0'. Thus, the control signal can be generated twice a reference frequency.</p> |
