Patent ID: 7298683
Filing Date: 2007-11-20
Classification: G11B

Abstract:
1. An optical information recording/reproducing apparatus that condenses a light flux from a light source on an optical recording medium and effects recording/reproduction of information, comprising: a light source; an objective lens for condensing a light flux from the light source; a spherical aberration generating mechanism, provided between the light source and the objective lens, for generating spherical aberration in the light flux; a sensor for receiving light reflected by an optical recording medium and converting the light into an electric signal; an equalization filter for effecting waveform equalization of an output from the sensor in accordance with a predetermined partial response characteristic; a quality evaluating circuit for measuring reproduction quality of an output signal from the equalization filter; and an adaptive equalization circuit for sequentially updating a coefficient for the equalization filter, wherein while the update of the coefficient for the equalization filter by the adaptive equalization circuit is stopped, the spherical aberration generating mechanism is driven on the basis of the reproduction quality measured by the quality evaluating circuit.