High Response Twin-Objective Actuator with Radial Tilt Function for Blu-ray Disc Recorder

Abstract

We have developed Blu-ray Disc (BD) optical pick-up with a twin-objective lens actuator which is compatible with compact disc (CD) and digital versatile disc (DVD) in the high-speed BD-read only memory (ROM) and BD Recorder. In order to readout CD and DVD in BD Recorder, we adopted twin-objective lens actuator in consideration of optical utilization efficiency, optical performance and insurance of sufficient working distance (WD). This twin-objective lens actuator has two objectives in radial direction, one is for CD/DVD and the other is for BD. Through our careful investigation in design process, this actuator has extremely high AC sensitivities and good 2nd resonance characteristics in consideration of twin-objective actuator. Also, this actuator has linearity in wide focus range, that is to say, more than ±1.0 mm and has radial tilt function which is tilt range more than 7 deg.