Patent ID: 8116188
Filing Date: 2012-02-14
Classification: G11B

Abstract:
1. A plastic objective lens configured to collect a light beam with at least a wavelength λ on a recording layer of an optical disk and used in an optical pickup for recording and/or reproducing an information signal by illuminating a light beam on the optical disk having one or more of recording layers in an incident direction of the light beam, wherein: an amount of 3rd order comatic aberration [λrms], which is caused when the objective lens is tilted by 1 degree, is a lens tilt sensitivity; the lens tilt sensitivity at an image height sensitivity of 0 is positive; and wherein under an environment in which a temperature range is 0° C. to 70° C. and a range of the wavelength λ of the light beam is 400 to 410 nm,