抄録
We developed a spherical aberration correction mechanism for a multi-layer Blu-ray Disc(BD) optical pickup.Lager movable range of a collimate lens is needed to correct the spherical aberration caused by different disc-thickness as the number of recording layer increases.First characteristic structure is that movable range of the collimate lens is located below an objective lens actuator.This structure makes it possible to maintain the size of a multi-layer BD optical pickup same as that of a conventional DVD optical pickup.Secondary characteristic structure is that a main-guide shaft,a sub-guide shaft and a lead screw are arranged at different heights.This arrangement makes a moment of force to a holder of the collimate lens,therefore,reduces a displacement of the holder to less than 1μm.
