Patent ID: 9633688
Date: 2017-04-25
CPC Classifications: G11B

Claim:
1. A reproducing device capable of reproducing content from an optical information recording medium in which the content is recorded in a form of a pit group including one or more pits shorter than an optical system resolution limit of the reproducing device, comprising: an irradiation section for irradiating the optical information recording medium with reproduction light; a conversion section for converting, into reproduction signal indicative of the content, light which reflected off the optical information recording medium; a signal quality evaluating section for evaluating quality of the reproduction signal converted by the conversion section; and a spherical aberration correcting section for correcting a spherical aberration caused by the irradiation section, by using a result of evaluation of the quality of the reproduction signal which quality has been evaluated by the signal quality evaluating section; wherein the signal quality evaluating section is an i-MLSE (Integrated-Maximum Likelihood Sequence Estimation) detecting section for (a) detecting an i-MLSE which is an evaluation index for evaluating a signal characteristic of the reproduction signal and (b) evaluating quality of the reproduction signal.