Diffraction element and optical pick-up assembly.

摘要

A diffraction element including a diffraction grating for dividing a light beam, emitted from a light source along a predetermined path, into a principal light beam and at least two auxiliary light b eams, and a hologram for separating the beam, which has been reflected from an optical information recording medium, from the predetermined path. The diffraction grating and the hologram are integrated together in the form as formed in opposite portions of a block of glass or plastics in alignment with each other. A slide provided in at least a portion of the diffraction element for sliding engagement with a cylindrical surface axial with an optical axis of the diffraction element to permit the diffraction element to be rotatable about the optical axis. <IMAGE>