| 摘要 |
PROBLEM TO BE SOLVED: To protect the optical disk against recording and reproducing by restricting transmissively or intercepting irradiation of laser light for recording and reproducing the optical disk. SOLUTION: An optical shutter mechanism 12 using liquid crystal is installed partly or completely between an optical pickup 6 for projecting the laser light and an optical recording surface 5 of the optical disk. The optical shutter mechanism 12 is composed of transparent electrodes 1 and 3, polarizing plates 2 and 4 and a liquid crystal layer 14 disposed between these polarizing plates. Then, connecting terminals 9 and 10 to be electrically connected with the transparent electrodes 1 and 3 are disposed in an optical disk mounting part 11, and a voltage is impressed upon the transparent electrodes 1 and 3 by an electric circuit for connecting a power source 13 to the connecting terminals 9 and 10 by using a switch 8, so as to control the liquid crystal layer 14. By this method, the laser light 7 to the optical recording surface 5 of the optical disk is transmissively restricted or intercepted. |
