Focusing lens system for an optical head assembly

摘要

A focusing lens system for an optical head has a plurality of objective lenses and a lens actuator including a cylindrical housing and a lens holder rotatably and slidably mounted by a shaft within the cylindrical housing. A switching mechanism selects one of the first and second lens for effecting tracking of the optical head depending on the type of an optical disk. The switching mechanism includes a pair of magnets mounted on the lens holder and a pair of associated coils secured on the inner wall of the cylindrical housing. The lens holder is further driven along the shaft for focusing of the selected lens.