| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical head device in which the light quantity on an optical recording medium is varied without changing the output of the outgoing light from a light source of an optical head device and the characteristics in a recording and a reproducing of information on an optical recording medium are made superior. <P>SOLUTION: In the optical path between a semiconductor laser 1 which is a light source of the optical head device and a condenser lens 5 which is a condensing means, a liquid crystal variable phase shifter 3, in which a liquid crystal layer is held between two transparent substrates having transparent electrodes, and a polarizer 4, which is provided on a light emitting side of the shifter 3 and used to vary the light quantity of the transmitted light beams in accordance with the polarization condition are arranged. A voltage controller 11 is connected to the respective transparent electrodes so as to apply voltages to the liquid crystal layer. <P>COPYRIGHT: (C)2004,JPO |
