Patent ID: 7903509
Filing Date: 2011-03-08
Classification: G11B

Abstract:
1. An information recording medium comprising: a substrate having a microscopic pattern, having a continuous shape of approximately parallel grooves formed with alternating groove and land sections; a recording layer formed on the microscopic pattern; and a light transmission layer formed on the recording layer, wherein the microscopic pattern is formed so as to satisfy a relation of P<λ/NA and a thickness of the light transmission layer is within a range of 0.07 to 0.12 mm, wherein P is a pitch of the groove section or the land section, λ is a wavelength of reproducing light beam and NA is a numerical aperture of an objective lens; and wherein the land section is wobbled in the radial direction and having a wobbled shape corresponding to a signal to be recorded on the land section resulting from the modulation of a phase modulated wave that is further modulated by a single frequency wave, the single frequency wave having a frequency of integral multiples or one over integral multiples of a frequency of the phase modulated wave, and wherein the frequency of the single frequency wave is different from that of the phase modulated wave, and further wherein a record mark for recording information is formed on a recording layer that is formed in either one section of the land section and the groove section.