OPTICAL PICKUP, OPTICAL DRIVE DEVICE, LIGHT IRRADIATION METHOD

摘要

Disclosed are an optical pickup, an optical drive device, and a light irradiation method capable of suppressing the degree of a spot displacement ?x. The optical pickup irradiates an optical recording medium which includes a reference surface and a recording layer through a common object lens for irradiating a first light used to record or reproduce information in the recording layer and a second light which is different from the first light, and adjusts a focus position of the first light irradiated through the object lens by changing the collimation of the first light to be incident on the object lens so as to suppress the spot displacement ?x between the first light and the second light to be generated in response to an eccentricity of the recording medium, wherein the reference surface has a reflective membrane which has a position guiding portion formed in a spiral shape, and the recording layer is provided in a layer position which is different from that of the reference surface and records information by forming a mark corresponding to irradiated light. The magnification of the second light is within the magnification range of the first light.