PURPOSE: To protect an optical component at a separated cross section from dust or dirt and to improve the reliability of the head and the practical performance in an unfavorable environment by approaching an optical system rotor and an optical system stator in nonoperation and covering a face of them approached together with a cover.

CONSTITUTION: A moving part 6 moves a rail 8 in nonoperation and is at a standstill or fixed at all times at a position closest to a stator 7 by a linear motor 9. A mirror 3 and a beam splitter 5 coupled optically are covered completely by a cover 10 being a container. The cover 10 is supported by the stator 7 and the drive main body is to be supported. Thus, the mirror 3 having the optical coupling face of the head and the beam splitter 5 are not exposed to the environmental atmosphere of the driver in nonoperation and the optical component is protected from dust and dirt. Moreover, in the operating state, since the moving part 6 is always moving, the probability of adhesion of dust and dirt is less.