| 摘要 |
PROBLEM TO BE SOLVED: To provide a multi-focus optical beam forming device, as well as a multi-focus pickup and an information reproducing device, that emits a light beam having multiple focuses capable of reproducing both CD and DVD without the irradiation of the reflected light of unnecessary light beams to a photodeterctor. SOLUTION: The device is provided with a dual focus mirror 10 that is equipped with a half mirror face HM, which reflects a part of a light beam L entered from the outside as a partial light beam L1 , with the beam made incident on an objective lens 11 and converged on DVD 1, and which reflects other part of the light beam L as a partial light beam L2 , and that is equipped with a reflected face RM which reflects the partial light beam L2 , with the beam made incident on the objective lens 11 and converged on CD2. |
