Light beam condensing apparatus and method of driving optical recording medium by applying the apparatus

摘要

A light beam condensing apparatus is provided for introducing a condensing spot of a laser beam onto an optical recording medium such as optical disks, and a method of driving the optical recording medium by applying the apparatus. The apparatus can include a modulator disposed between a collimate lens and an objective lens. The modulator can be mechanically or electrically driven to control and vary the amplitude or phase of a collimate beam. Further, the modulator can be switched according to an operational mode of a drive unit or a type of a recording medium so as to provide a desired condensing spot shape.