Funai Electric Company Ltd.

Wataru Kuze

Hitoshi Fujii

Akira Ishii

Susumu Sugiyama

Katsuhiko Tanaka

Fuminori Tanaka

Kenji Nagashima

In a variable-shape mirror provided with 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, and piezoelectric elements that are sandwiched between the support base and the mirror portion and that vary the shape of the mirror surface, the piezoelectric elements are bonded, by means of a thin layer of metal, to at least one of the support base and the mirror portion by the application of heat and pressure.

Fabrication method for variable-shape mirror using thermo-compression bonding

The variable-shape mirror is provided with a support base and a minor portion that is disposed to face the support base and that has on a side thereof facing away from the support base a minor surface which is irradiated with a light beam. There are also provided piezoelectric elements that are sandwiched between the support base and the mirror portion and that vary the shape of the mirror surface. The piezoelectric elements are bonded, through a thin layer of metal that is separately provided for bonding, to at least one of the support base and the mirror portion. A driving voltage to the piezoelectric elements is supplied through the thin layer of metal.

Variable-shape mirror and optical pickup device therewith

In a variable-shape mirror of which the shape of the mirror surface can be varied, a mirror portion is bonded only to a fixed portion and not to a piezoelectric element. When the piezoelectric element is not operating, the mirror portion, receiving a predetermined force from the piezoelectric element, makes contact with the piezoelectric element. When the piezoelectric element contracts, the mirror portion tends to restore its original shape by its counterforce. Thus, even when the piezoelectric element contracts, the contact between the mirror portion and the piezoelectric element is held, and hence the electric conduction to the piezoelectric element is maintained.

A variable-shape mirror is provided with: 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; fixed portions that fix the mirror portion to the support base; and piezoelectric elements that are sandwiched between the support base and the mirror portion and that vary a shape of the mirror surface. Here, the piezoelectric elements are arranged closer to a center of the mirror portion than the fixed portions are.

In a variable-shape mirror () of which the shape of the mirror surface can be varied, four piezoelectric elements () are sandwiched between a support base () and a mirror portion (), and are arranged symmetrically in cross-shaped directions. The piezoelectric elements () are bonded to the mirror portion (), and serve both to vary the shape of the mirror portion () by being driven and to fix the mirror portion () to the support base (). Support portions () are arranged one inside each of the piezoelectric elements (). With this structure, a small movement that the piezoelectric elements () produce when driven can be converted into a large movement of the mirror portion ().

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Osaka, Japan

Wataru Kuze