Patent ID: 8582399
Filing Date: 2013-11-12
Classification: G11B

Abstract:
1. An information storage medium for storing modulated data, comprising: a burst cutting area; a system lead-in area located outward of the burst cutting area; and a data area located outward of the system lead-in area, wherein the burst cutting area comprises a first area and a second area, the system lead-in area comprises a third area and a fourth area, the first area and the third area are configured to store same information relating to a version number, the second area and the fourth area are configured to store same information relating to a recorded mark polarity flag, the first area, the second area, the third area, and the fourth area comprise microscopic concave-convex shapes, the recorded mark polarity flag indicates a low-to-high characteristic or a high-to-low characteristic, the low-to-high characteristic indicates that recorded marks have a higher reflectivity than unrecorded portion, and the high-to-low characteristic indicates that recorded marks have a lower reflectivity than unrecorded portion, the modulated data has a minimum inversion length and a maximum inversion length, the minimum inversion length corresponds to 2T, T being a channel bit length T of the modulated data, the modulated data is configured to be reproduced by a reproducing apparatus, the modulated data is configured to produce a reproduction signal when the reproducing apparatus reproduces the modulated data, a high level value of a reproduction signal amplitude is a highest value reproduced from an area regarding the maximum inversion length, a low level value of the reproduction signal amplitude is a lowest value reproduced from an area regarding the maximum inversion length, a differential value is defined as a difference between the high level value and the low level value, and a ratio of the differential value to the high level value is more than 0.2.