Patent ID: 7355945
Filing Date: 2008-04-08
Classification: G11B

Abstract:
1. An adjustment apparatus for an optical pickup comprising: a disc rotating unit for rotationally driving an optical disc for adjustment mounted thereon, said optical disc being adapted for use in adjusting an optical pickup and having at least two signal recording layers, there being concentrically recorded in the respective signal recording layers data modulated in accordance with the same modulation system but with respective different physical formats; said optical pickup being configured for collecting a light beam radiated from a light source with an objective lens and for detecting a return light beam reflected back from said optical disc for adjustment by a photodetector, said optical pickup displacing said objective lens by an objective lens driving unit in a direction along an optical axis of said objective lens and in a direction perpendicular to said optical axis; adjustment means for adjusting relative positions of said light source and the objective lens and for adjusting a tilt of the optical axis of the objective lens; said adjustment means illuminating said light beam to one of said two signal recording layers of said optical disc for adjustment, arranged in a preset position relative to said optical disc for adjustment, for adjusting the relative positions of said light source and the objective lens, said objective lens driving unit displacing said objective lens along the optical axis thereof by said objective lens driving unit, said light beam being illuminated on another signal recording layer of the optical disc for adjustment in order to adjust the relative positions between said light source and the objective lens; and wherein the adjustment on the light beam that illuminates said one of the signal recording layers is carried out by rotationally adjusting said light source so that a phase difference of ± first order light, centered about zero order light, will be 180°, said zero order light and said ± first order light being illuminated from said optical pickup to said optical disc for adjustment.