Patent ID: 8897107

Claim:
A playback device comprising: a light source; an objective lens that radiates light emitted by the light source onto an optical recording medium, and onto which is incident reflected light obtained from a recording surface of the optical recording medium in accordance with the radiated light; a condenser lens, onto which is incident the reflected light obtained via the objective lens, that condenses the reflected light; a photodetecting section configured in a manner that, provided that a confocal position is a focal position of the condenser lens when the light emitted by the light source is focused onto the recording surface by the objective lens, λ is a wavelength of light radiated onto the optical recording medium by the objective lens, and NA is a numerical aperture of the objective lens, the photodetecting section extracts and detects light within a range of a diameter less than 1.5λ/NA centered on an optical axis at the confocal position, the light being central light of the reflected light at the confocal position; and a phase difference imparting section, inserted on a light path from the light source to the photodetecting section, that imparts a designated phase difference between a reflected light component from a readout track and a reflected light component from a track neighboring the readout track from among tracks formed on the recording surface of the optical recording medium, wherein the photodetecting section extracts the central light of the reflected light with a pinhole disposed at the confocal position.