Quality evaluation method, information recording medium, optical disc device and recording/reproducing system

摘要

When data is recorded on an optical disc, and stored for a long period of time, there is a need to periodically evaluate whether a quality of the recorded data is determined with time, or not. If the signal quality is lower than a given level as an evaluation result, a work for moving the data to a brand-new optical disc is required. However, in periodical inspection, if the number of optical discs is enormous, a large amount of time is required to evaluate all data recorded on the optical disc. In recording user data on the optical disc, a signal of a particular pattern having a lifetime shorter than a reference lifetime of the user data is recorded in a given area of the optical disc in advance, the particular pattern signal is reading at given time intervals, and processing on the user data is determined on the basis of the evaluation result of the signal quality.

主权项

1. A quality evaluation method comprising:
irradiating a particular pattern on a recording medium in a plurality of recording media to read a particular pattern signal therefrom, the particular pattern having a lifetime shorter than a reference lifetime of user data recorded in a user data area, the particular pattern recorded outside the user data area; evaluating a quality of the particular pattern signal; and determining a quality of the user data based on the evaluated quality of the particular pattern signal, wherein the reference lifetime is an intermediate value in a user data lifetime distribution that corresponds to a lifetime value for which user data recorded on a percentage of the recording media in the plurality of recording media is preserved.