| 摘要 |
<p>PURPOSE:To prevent an error generated at an editing point in a slow motion editing mode by comparing the count value obtained by counting the pulses whose cycles are changed in accordance with the tape driving speed with the reference count value obtained by counting the pulses which are controlled in response to the set tape driving speed. CONSTITUTION:The drive of a magnetic tape 11 is detected by a timer roller 12, and double phase pulses whose frequencies are proportional to the tape driving speed with phases varying the tape driving direction are counted. Then the count value (f) is sent to a comparator 16. While a reference pulse (g), the initial value (i), the driving direction set value (j), etc. are supplied to a counter 21 from a frequency divider 20. Then the reference pulses are counted. The count value (f) showing the tape address, the reference count value (h) showing the reference address and the set value (j) are supplied to the comparator 16. If no coincidence is obtained between the values (f) and (h), the driving speed of the tape 11 is controlled to obtain the coincidence between both values. Then the driving quantity, i.e., the present address of the tape 11 is controlled.</p> |
