| 摘要 |
An optical pickup device, an optical recording/reproducing apparatus and a gap control method are provided to control the gap between the condensing optical system and an optical recording medium with high precision when irradiating near-field light to the optical recording medium and to implement both feed-forward servo control and tilt servo control using tangential push-pull signal. An optical pickup device comprises a light source(2), a condensing optical system irradiating near field light to an optical recording medium(20), an optical detector(9) detecting the entire reflection amount of light returned from the optical recording medium, a controller(10) producing control signal in response to the detection signal obtained from the optical detector, and a driving part(11) operating the condensing optical system at the specific location on the optical recording medium. The controller includes a repetitive controller producing gap servo signal and preserving a certain amount of push-pull signal.
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