Patent ID: 9111553
Filing Date: 2015-08-18
Classification: G11B

Abstract:
1. A read-only optical information recording medium on which a content is recorded as a pit group formed such that an average length Tm [nm] of a minimum mark length and a minimum space length becomes shorter than an optical system resolution limit of a reproduction apparatus in which a numerical aperture of an objective lens is 0.85 and a wavelength of a reproduction light is 405 [nm], wherein as a reading speed for reproducing the content, reading speed information designating a reading speed in a range from 2×(4.92×Tm/149) [m/s] to less than (10000/60)×2×π×(24/1000) [m/s] is recorded, reproduction light output information designating a reproduction light output corresponding to the reading speed indicated by the reading speed information is recorded, and a frequency of a reading clock corresponding to the reading speed indicated by the reading speed information is an n multiple (n is an integer of 2 or more) of a frequency of a reading clock corresponding to a reading speed for reading the pit group formed such that the average length of the minimum mark length and the minimum space length is not less than the optical system resolution limit.