OPTICAL DISK BIT ERROR MEASURING INSTRUMENT

PURPOSE:To attain bit error ratio measuring at high speed at which an effect such as data transfer speed is negligible by recording data from a memory in units of a sector while circulating the data at every recording. CONSTITUTION:A first control means 11 adds address offset corresponding to at least one sector at every track recording by means of an address offset applying means 13 to the read address of a memory 12 by a recording means, repeats the recording for prescribed times while circulating the test data, next, activates a reproducing means, the data after repeated recording are reproduced, and a second control means 5 measures the bit error of the reproduced data. In such a way, the repeated bit error ratio of the recording of the erasing optical disk can be measured at high speed without using a special computer at high performance.