| 摘要 |
PURPOSE:To facilitate the correction of an error item, by displaying clearly the error item when an address which does not exist is accessed. CONSTITUTION:The output of a comparator 2 is inverted when an address read in the stage of the retrieval on every tracks corresponding to one rotation becomes larger or smaller than an object address. Values of addresses read in retrieval for normal reproducing just before and after this inversion are compared with the value of the object address inputted to an input part 1 to discriminate whether the object address exists or not. If the object address does not exist, a part in which the object address is different from a maximum address smaller than the object address (or a minimum address larger than the object address) is detected. This different part is displayed on a display part 4 to indicate that the inputted object address does not exist. |
