METHOD AND APPARATUS FOR MEASURING OPTICAL RECORDING MEDIUM OR THE LIKE

摘要

PROBLEM TO BE SOLVED: To provide a method and an apparatus for measuring an optical recording medium or the like which mainly clarify the relation between the displacement of a DVD disk and an adhesive layer (adhesive layer). SOLUTION: An optical sensor 8 in a displacement read mode detects a reflected light beam 12a which is a measuring light beam 12 from the sensor 8 reflected by the 1st reflective surface (a) of the disk layer of a 1st disk layer 2, and the displacement value A of the 1st reflective surface of the disk layer is measured. Then, the sensor 8 is automatically changed into a thickness read mode, and moves to a region where the sensor 8 cannot measure the 1st reflective surface (a) of the disk layer 2 (the sensor 8 approaches a disk surface). The displacement value B (the displacement value B of the 1st reflective surface (b) of an adhesive layer 3) of the 2nd reflective surface of the disk layer which is a distance to the 2nd reflective surface (b) of the disk layer (the 1st reflective surface (b) of the adhesive layer 3), and the displacement value C of the 2nd reflective surface of the adhesive layer which is a distance to the 2nd reflective surface (c) of the adhesive layer are measured to calculate the thickness E of the adhesive layer 3.