OPTICAL INFORMATION DEVICE, AND INFORMATION RECORDING/REPRODUCING DEVICE

摘要

It is possible to realize stable tracking control for an optical recording medium having a plurality of information recording surfaces. For this, an optical information device includes a light source for emitting an optical beam, converging means for collecting the optical beam emitted from the light source onto a predetermined information recording surface of the optical recording medium having a plurality of information recording surfaces, beam division means for dividing the optical beam reflected by the optical recording medium, and photo-detection means having a light reception unit for receiving the optical beam divided by the beam division means and outputting a signal in accordance with the light intensity of the optical beam received by the light reception unit. A guide groove is formed on at least one of the information recording surfaces. The light reception unit is arranged entirely in a map formed on the photo-detection means by the optical beam reflected from the information recording surface other than the predetermined information recording surface (hereinafter, referred to as non-light-collecting surface).