Patent ID: 6882614

Claim:
A recording and/or reproducing apparatus compatible with disks having different thicknesses, comprising: an optical pickup device comprising: a light source to emit a light beam along a common optical axis, an objective lens having a surface with regions which are optimized to selectively focus the light beam on the disks having the different thicknesses depending upon the thicknesses of the disks, with at least one region having an optical property to focus the light beam received at an angle relative to the common optical axis onto one of the disks but does not focus the light beam received at the angle onto another of the disks according to the thicknesses of the disks and at least one other region surrounding the common optical axis having an optical property to focus the light beam received at the angle onto the disks independent of the thicknesses of the disks, and a photo detector to detect the light beam reflected from the disks having the different thicknesses; and a processing unit to process an information signal to control the light beam generated by the light source, and to process the detected light beam from the photo detector.