Patent ID: 7499389
Filing Date: 2009-03-03
Classification: G11B

Abstract:
1. An information storage medium capable of reproducing information recorded thereon as marks with a size less than a resolution limit of an incident light beam, wherein: the information storage medium contains a plurality of marks of various sizes recorded thereon, excluding marks with a size near the resolution limit, the resolution limit depends on a wavelength of a light source irradiating light on the information storage medium and a numerical aperture of an object lens focusing the light irradiated from the light source on the information storage medium, and when λ denotes the wavelength of the light source, NA denotes the numerical aperture of the object lens, and mT (where m is a real number) denotes at least one mark with a size in the vicinity of the resolution limit among the marks, mT has a size in the following range: