Variable-shape mirror and optical pickup device therewith

A variable-shape mirror comprising:

• a support base;
• a mirror portion that is disposed to face the support base and that has, on a side thereof facing away from the support base, a mirror surface which is irradiated with a light beam;
• piezoelectric elements that are sandwiched between the support base and the mirror portion and that vary a shape of the mirror surface;
• and
• fixed portions, each of which corresponding to one of the piezoelectric elements, sandwiched between the support base and the mirror portion, and disposed closer to an outer edge of the mirror portion than said each of the corresponding piezoelectric elements is,
• wherein each of the piezoelectric elements has first and second thin layers of metal on both ends thereof, respectively,
• the mirror portion has first projections provided on a side facing the support base and third thin layers of metal, each of which is provided on a bottom face of each of the first projections, and each of the third thin layers of metal making contact with the first thin layer of metal,
• the support base has individual electrodes, each of which electrodes comprises a second projection provided on the support base and a fourth thin layer of metal provided on a top face of the second projection, the fourth thin layer of metal making contact with the second thin layer of metal,
• each of the fixed portions is bonded to the mirror portion without interposing a thin layer of metal therebetween,
• each of the piezoelectric elements is bonded to the support base through the second and fourth thin layers of metal and the second projection, and bonded to the mirror portion through the first and third thin layers of metal and the first projection, and
• when a driving voltage is applied to each of the piezoelectric elements through the first, second, third, and fourth thin layers of metal, the piezoelectric elements expand and contract vertically to thereby deform the mirror surface.