| 摘要 |
An optical information recording-reproducing apparatus for effecting at least one of recording of information on and reproducing of information from an optical recording medium. A light source emits a light beam. An objective lens and a solid immersion lens receive the light beam from the light source and approach the optical recording medium at a predetermined speed to focus the light beam onto the optical recording medium. An aperture element collects a portion of the light beam that is reflected by the recording medium, in which the portion of the light beam has a diameter that corresponds to an effective aperture number of the objective lens and the solid immersion lens of less than one. A detecting element detects the portion of the light beam collected by the aperture element and produces an output signal. A speed-generating circuit receives the output signal from the detecting element and determines the speed of approach of the solid immersion lens to the recording medium, in accordance with the output signal, and produces an output. A driver circuit drives the objective lens and the solid immersion lens and reduces the speed of approach of the solid immersion lens, in accordance with the output from the speed-generating circuit.
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