PURPOSE: To make the optical system light weighted, to quicken and make various operations stable, by providing a sub-arm for a main arm having the 1st optical system, and a sub-drive means and the 2nd optical system having a condenser lens opposing to the 1st optical system for the sub-arm.

CONSTITUTION: The radial feeding is performed by a main driving means 1. The beam of the 1st optical system 3 is made incident to a condeser lens of the 2nd optical system 5 at the opposing position and forms the spot of a disc. Thus, the spot can be moved with the main drive means 1. The reflected beam returns to the 1st optical system 3 via the 2nd optical system 5 and obtains recording information and a control signal. A sub-drive means 7 receives the said control signal for focusing and tracking. This drive is performed with coils 9,10 and 11 for three axis drive fitted with a driving arm 8 of a sub-arm.