| 摘要 |
PURPOSE: An optical pick-up and a reproduction device is to reliably reproduce information recorded on a high-density optical disc with a very small track pitch. CONSTITUTION: A laser beam generated from a light source(2) is converted to a parallel beam by a collimator lens(4) and is incident on a quarter wavelength plate(6), which is provided between the collimator lens and a half-reflective mirror(8) to convert the incident beam from the collimator lens into a circularly polarized light. The half-reflective mirror installed between the quarter wavelength plate and an objective lens(10) separates the circularly polarized light into linearly polarized light having different components in a track direction, and reflects it toward the objective lens. The half-reflective mirror is also located between the objective lens and a beam splitter(12) to transmit a beam reflected from an optical disc(1) toward the beam splitter. A central portion of the half-reflective mirror reflects a vertical linear polarized light or a horizontal one toward the objective lens corresponding to an object track on which information to be reproduced is recorded, while a peripheral portion thereof reflects them toward the objective lens corresponding to peripheral tracks adjacent to the object track.
|
