| 摘要 |
PROBLEM TO BE SOLVED: To reproduce a high density optical disk and a low density optical disk with a general condenser lens designed for the high density optical disk by providing a plural optical path forming element and constituting so that a virtual light emission point is provided on one among plural luminous flux formed on that. SOLUTION: Light emitted from a light source 11 is separated to plural luminous flux by the plural optical path forming element 21, and are converged on different positions by the condenser lens 40. At this time, at least one among plural luminous flux formed by the plural optical path forming element 21 is made be provided with the virtual light emission point 12a different from a real light emission point 11a. Thus, the matter that wave front aberration caused on plural luminous flux due to the difference of light emission point positions is controlled to a proper size becomes possible, and plural kinds of recording media are reproduced by one condenser lens. |
