OPTICAL PICKUP CAPABLE OF REDUCING A FOCUS OFFSET, AND AN OPTICAL RECORDING AND PRODUCING APPARATUS ADOPTING THE OPTICAL PICKUP, ESPECIALLY CONCERNED WITH REDUCING AN INFLUENCE OF BEAM HAVING HIGH STRENGTH IN A SIGNAL DETECTED BY AN OPTICAL DETECTOR

摘要

PURPOSE: An optical pickup, and an optical record and regeneration apparatus are provided to reduce a focus offset though there remains aberration in a beam received by a light detector due to a phase difference generated from a compensation element for a compensation for a spherical aberration. CONSTITUTION: The optical pickup comprises an optical source(10), an object lens(30), an optical detector(40), a compensation device(20). The object lens(30) focuses a beam radiated by the optical source(10) on a recording medium so as to form an optical spot. The optical detector(40) receives the beam reflected on the recording medium, and detects data signals or error signals. The compensation element(20) compensates for spherical aberration caused by a thickness difference of the recording medium with respect to a beam emitted from the optical source(10) toward the recording medium.