| 摘要 |
PROBLEM TO BE SOLVED: To provide a mirror capable of remarkably changing the curvature by a small deformation amount, and to provide an optical pickup device capable of miniaturizing the device constitution, reducing the driving power, and reducing the running cost. SOLUTION: This mirror is a curvature variable mirror 10 provided with a mirror main body 1 having a curved surface part 1a and a flange part 1b, a deformation member 2 consisting of dielectric material, forming electrodes 3, 3' on its upper/lower both side surfaces and connected to the flange part 1b of the mirror main body 1 and a power source circuit provided with a DC power source 4 and a switch 5 and connected to the electrodes 3, 3', and when the switch 5 is turned ON, electric charges are loaded on the electrode 3, and an electric field occurs in the deformation member 2. Then, the deformation member 2 is deformed in the radial direction by a piezoelectric effect, and compression force is imparted from the deformation member 2 to the curved surface part 1a. Thus, since the curved surface part 1a is shrunk in the radial direction, and is expanded in the curved surface direction, the curvature of the curved surface part 1a is reduced. |
