| 摘要 |
<p>RANDOM ACCESS STORAGE DEVICE WITH A MOVABLE RECORDING MEDIUM A random access storage device has signals recorded on tracks (assigned addresses in advance) on a rotary recording medium such as an optical video disk. These addresses are randomly searched for at high speed. Erroneous searches attributable to a transient phenomenon such as a jump for the search, a drop-out, etc. are prevented. To this end the device has 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 moved is read. Whether or not the address signal is normal is decided by the error check circuit. If the address signal is decided to be normal, it is stored in a register as a reference address. A light spot is deflected by the number of tracks that correspond to the difference between the reference address of the register and the target address. If the address signal is decided to be abnormal, the light spot is unconditionally deflected onto the adjacent track. An address signal is again read out at the new position. Thereafter, the error decision and the other above described operation are again carried out.</p> |
