MEASURING METHOD OF CHARACTERISTICS DATA TO MULTILEVEL OPTICAL STORAGE-MEDIUM AND MULTILEVEL OPTICAL STORAGE- MEDIUM TO WHICH PATTERN FOR MEASURING THE CHARACTERISTICS DATA IS RECORDED

摘要

PROBLEM TO BE SOLVED: To provide a method for simply and accurately measuring the asymmetry of a multilevel optical storage medium. SOLUTION: A step which measures a light reflectivity to a first virtual record cell row S00 in which more than one virtual record cell S0 is consecutively formed, a step which measures the light reflectivity to a second virtual record cell row S77 in which more than one virtual record cell S7 is consecutively formed and a step which measures the light reflectivity to a third virtual record cell row S07 in which the virtual record cell S0 and the virtual record cell S7 are alternately arranged are provided. The values of the light reflectivity obtained from the first and second virtual record cell rows S00 and S77 are values under the condition that the accordance of an adjacent virtual record cell with the contents of the virtual record cell concerned is guaranteed, and the value of the light reflectivity obtained from the third virtual record cell row is a value under the condition that the difference of the adjacent virtual record cell from the contents of the virtual record cell concerned is guaranteed.