Optical pickup head

Claim 1

An optical pickup head operating on an optical recording medium, comprising: a light source emitting a light beam; a reflecting section reflecting the light beam emitted from the light source and changing a direction of travel of the light beam emitted from the light source into a first predetermined optical path; a holographic optical element receiving the light beam from the reflecting section via the first predetermined optical path, diffracting the light beam which has been reflected by the reflecting section, and generating a forward diffraction light beam from the light beam which has been reflected by the reflecting section; means for focusing the forward diffraction light beam generated by the holographic optical element on the optical recording medium, wherein the forward diffraction light beam is reflected and diffracted by the optical recording medium so that a return light beam is generated by the optical recording medium from the forward diffraction light beam; the holographic optical element receiving the return light beam from the optical recording medium, diffracting the return light beam, generating a backward diffraction light beam from the return light beam, and directing the backward diffraction light beam in a second predetermined optical path which differs in position from the first predetermined optical path; the reflecting section receiving the backward diffraction light beam from the holographic optical element via the second predetermined optical path, reflecting the backward diffraction light beam, and changing a direction of travel of the backward diffraction light beam; and means for detecting the backward diffraction light beam which has been reflected by the reflecting section.