| 摘要 |
PROBLEM TO BE SOLVED: To deal with various optical master disks by converging laser beams at the incident side of an objective lens, varying the diameter of the beams and changing the central spot diameter of the converged beams on a photosensitive layer or a surface layer. SOLUTION: Parallel light beams 12 generated by a laser light beam generator 11 are converged while passing a convergence hole 15 of a convergence plate 14 of a convergence changing mechanism 13, reflected by a mirror 15 and converged on a photoresist 19 of a glass master disk 18 by an objective lens 17. The diameter of the central spot of the converged beams, which irradiate the photoresist 19 of the disk 18, become the value which is varied by changing the diameter of the incident light flux by the mechanism 13 which constitutes a variable convergence device and an optical master disk exposing recording is conducted correspondingly to many kinds of optical disks. |
