Patent ID: 8144565
Filing Date: 2012-03-27
Classification: G11B

Abstract:
1. An optical head comprising: a light-emitting element for emitting a light beam; a first polarized light diverging element wherein among all the light beams emitted from said light-emitting element, the light beam of a first polarization direction is transmitted, and the light beam of a second polarization direction orthogonal to the first polarization direction is reflected in a direction different from said optical axis of the light beam of the first polarization direction; a second polarized light diverging element for transmitting or reflecting the light beam of the first polarization direction that has been transmitted through said first polarized light diverging element; a converging element for converging, on an information recording medium, the light beam transmitted through or reflected on said second polarized light diverging element; a reflection element for reflecting the reflected light beam reflected on said information recording medium and reflected on or transmitted through said second polarized light diverging element; and a detection element for detecting the reflected light beam reflected on said reflection element and transmitted through or reflected on said second polarized light diverging element; wherein said information recording medium includes a plurality of information lavers; and wherein said reflection element includes a separation means for separating the reflected light beam reflected on a predetermined information layer of said information recording medium from the unreguired reflected light beam reflected on a different information layer from said predetermined information layer.