| 摘要 |
PROBLEM TO BE SOLVED: To make the diameter of irradiating laser beams to be in a tolerance range even when the center of the irradiating beams is deviated from the center axis of optical elements by regulating the diameter of light beams to be irradiated on the magneto-optical recording layer of an optical recording medium with a light transmission hole. SOLUTION: The diameter of the laser light beams converged with a front lens 41 passes through a coil supporting substrate 44 in a state in which it is larger than the diameter of the center hole 47a of a magnetic core 47 and when it passes through the center hole 47a, one part of the circumferential side of the beams is kicked off by making the hole an aperture and the diameter of the laser light beams passing through the hole 47a is determined and the light beams are irradiated on the magneto-optical recording layer of the optical disk. As a result, when the center of the laser light beams is deviated from the center axis of a magneto-optical head part 25 due to the inclination of an optical axis and the assembling error of the part 25, the fluctuation of beam diameters can be made small in the degree of the tolerance range. Thus, it is not needed to set the diameter of the center hole of the coil part 46 larger by considering the inclination of the optical axis of the laser light beams and the assembling error of the part 25 and magnetic fields can be generated efficiently with a low power consumption and the suppressing of disconnections of thin film coils forming a coil part 46, or the like is made possible. |
