| 摘要 |
In a storage apparatus wherein signals recorded on tracks assigned addresses in advance on a rotary recording medium such as an optical video disk are randomly searched at high speed, a random access storage apparatus is provided in which erroneous searches attributed to a transient phenomenon due to a jump for the search, a drop-out, etc. are prevented. The storage apparatus includes an error check circuit. In a random access operation, a read head is mechanically moved to the vicinity of a target address, whereupon an address signal of a track to which the head has been moved is read. Whether or not the address signal is normal is determined by the error check circuit. If the address signal is determined to be normal, it is stored in a register as a reference address. A light spot is deflected by the number of tracks which corresponds to the address difference between the reference address of the register and the target address. If the address signal is determined to be abnormal, the light spot is unconditionally deflected onto the adjacent track and an address signal is read out at the new position of deflection. Thereafter, the error decision and the subsequent operation described above are carried out. |
