Patent ID: 6660986
Filing Date: 2003-12-09
Classification: G11B

Abstract:
An information reading and recording apparatus for recording media, comprising:a semi-conductor laser; a photo-detector adapted to detect reflection light from two types of recording media having respective recording densities different from each other; a collimating lens adapted to collimate a light beam from the semi-conductor laser; two objective lenses adapted to converge the light beam onto the two types of recording media, respectively, and having respective numerical apertures adapted for recording and reading of the respective recording media; and a super-resolution cut-off means disposed immediately before one of the two objective lenses adapted for one recording medium with a high density of the two types, the super-resolution cut-off means adapted to partly block the light beam thereby limiting a diameter of a focal spot, wherein the two objective lenses and the super-resolution cut-off means are integrated with means for switching between the two objective lenses and with an actuator driving system enabling a position of the two lenses to be controlled with respect to a recording surface of the recording medium, and whereby information is read and recorded in the two types of recording media having respective recording densities different from each other.