Designation address access manner null of videodisc pre- -

摘要

PURPOSE:To cancel reproduction mistake by interrupting the reproduction and returning the reproduction position near a preceding address when a clock generation circuit is identified to be incapable to execute acquisition of synchronism before a specified address is reproduced. CONSTITUTION:When the master clock generation circuit B does not reaches the acquisition state of synchronism and does not generate a lock impulse until a timing pulse is generated, as unlock output is inputted to a set pulse generation means 5 by a lock state detection means 14, an address comparator circuit 7 is reset and operated. As a result, a pickup is compulsorily returned to the preceding address and the regular reproduction is executed again. On the other hand, when the master clock generation circuit B finishes the acquisition of synchronism and generates the lock impulse before the timing pulse is generated, lock output is inputted to a switching circuit 11 and still picture video data is produced.