| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical pickup device which can improve the optical spots to two types of recording media of different substrate thickness via a single objective lens, can deal with these different types of recording media, can decrease the number of component parts and also can use an inexpensive light source. SOLUTION: This device synthesizes the luminous flux received from light source 1 used for the recording medium of the 1st substrate thickness with the luminous flux received from a light source 9 used for the recording medium of the 2nd substrate thickness via a luminous flux synthesizing element 3 and irradiates the recording media with this synthetic luminous flux via an objective lens 6. A 1st aperture element 5 decides the NA of the luminous flux received from the source 1 between the lens 6 and the element 3, and a 2nd aperture element 11 decides the NA of the luminous flux received from the source 9 between the element 3 and the source 9 respectively. |
