a deck with a central hole provided on a central portion of the deck;

a pair of guide shafts provided on the deck on opposite sides of the central hole;

a spindle motor provided at a predetermined position on the deck and coupled to a turntable on which an optical disk is placed;

an optical pickup movably supported at opposite sides thereof by the pair of guide shafts, with an objective lens provided in the optical pickup; and

an optical pickup actuating unit to reciprocate the optical pickup in a radial direction of the optical disk, and including:

a drive motor provided on the deck on a predetermined side of the central hole; and

an optical pickup conveying body coupled at a first surface thereof to the optical pickup and coupled at a second surface thereof to the drive motor through a gear train to move said optical pickup along said pair of guide shafts, wherein said coupling includes a rack-and-pinion member including a first rack attached to a disk reader and having with a first set of rack teeth and a first gear attached to said driving motor to reciprocate said disk reader, the coupling further includes a second rack-and-pinion member with a second rack disposed perpendicularly to the first rack and a second gear engaging said second rack to reciprocate a cover;

an objective lens protective unit, including a cover to cover the objective lens and being linearly reciprocated by the drive motor in a direction crossing the pair of guide shafts, thus covering and uncovering the objective lens.