| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup device equipped with a plurality of light sources having different wavelengths and different optical path lengths of emitted optical beams, and capable of reducing the number of optical elements by setting the number of pieces of photodecting means to 1, and preventing complex adjustment of optical components. <P>SOLUTION: The optical pickup device 1 includes a 2-wavelength compound light source 2 capable of emitting 2-wavelength optical beams, and a light source 3 for emitting a single wavelength optical beam. A laser beam emitted from the light source 3 has an optical length different from that of a laser beam emitted from the 2-wavelength compound light source 2. A lens effect for adjusting a difference in optical length between the light source 3 and the 2-wavelength compound light source 2 is imparted to one surface 8a of a hologram element 8 installed in the optical pickup device 1. A light control function for generating a servo signal is imparted to the other surface 8b of the hologram element 8. <P>COPYRIGHT: (C)2007,JPO&INPIT |
