| 摘要 |
PROBLEM TO BE SOLVED: To obtain the optical pickup in which a CD and a DVD(digital video disk) are reproduced using a common optical system and a single light receiving element and a CD-R is reproduced without damaging its reflection film. SOLUTION: The pickup is provided with a first semiconductor laser 1, a second semiconductor laser 2 which has a longer wavelength than the laser 1, a prism 3 which leads the laser beams from the lasers 1 and 2 into a same direction, a collimating lens 4 which makes the laser beams, that passed the prism 3, into parallel beams, an objective lens 6 which converges the paralleled beams onto a recording medium 10 and a light receiving element 7 which receives the reflected light beams from the medium 10. The prism 3 has a first inclined plane 31 which partially reflects the laser beams from the laser 1 and a second inclined plane 32 which partially reflects the laser beams from the laser 2. The lasers 1 and 2 emit respective laser beams in opposite directions and in parallel. Note that the lasers 1 and 2 are arranged at their respective conjugate positions against the single light receiving element 7. |
