Objective lens for optical recording/reproducing device
AssigneePENTAX Corporation
InventorWataru Kubo
Life of this patent
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Abstract
There is provided an objective lens which has positive refractive power and has a single lens element having an incident surface from which the collimated beam enters and an exit surface from which the collimated beam emerges. Further, the incident surface and the exit surface are configured to be rotationally symmetrical aspherical surfaces. At least within an effective diameter of the single lens element, the incident surface and the exit surface are symmetrical with respect to a plane perpendicular to an optical axis of the single lens element and have the same shape.
Claims6
An objective lens for an optical recording/reproducing device which records/reproduces information to/from a recording medium utilizing holography, said objective lens converging a collimated beam in the vicinity of a recording surface of the recording medium to record/reproduce the information, said objective lens comprising a single lens element having an incident surface to which the collimated beam enters and an exit surface being opposite to said incident surface, said incident surface and said exit surface being configured to be rotationally symmetrical aspherical surfaces, at least within an effective diameter of said single lens element said incident surface and said exit surface being symmetrical with respect to a plane perpendicular to an optical axis of said single lens element and having the same shape, said single lens element having positive refractive power.
Dependencies are inferred from the claim text.