Dai-ichi Seiko Co., Ltd.

Yoshifumi Ikeda

Kenji Ogata

Shogo Kurogi

Kazuhiro Okada

Satoshi Era

Shinya Sakamoto

Yoshiyuki Watanabe

A piezoelectric driver () includes n piezoelectric layers (A toD) (where n is an integer equal to or greater than 2) that are stacked, with electrode layers (B toD) each interposed between any adjacent piezoelectric layers, and with electrode layers (A andE) further formed underneath the lowermost piezoelectric layer (A) and on top of the uppermost piezoelectric layer (D), and the piezoelectric driver () is bent and displaced in the direction in which the piezoelectric layers are stacked. A signal converter () converts an n-bit digital signal (IS) into n bits of a bit string data signal (BS) comprising of bit data indicating whether a drive voltage to be applied to each of the piezoelectric layers (A toD) via the electrode layers (A toB) is on or off. An output device () outputs, in accordance with values of the individual bits in the bit string data signal (BS) provided through conversion performed by the signal converter (), drive voltages to be applied to the individual piezoelectric layers (A toD).

Speaker system

Actuators (), which are a pair of members, are disposed one on either side of a movable frame () in the X-axis direction, and oscillate the movable frame () about the X axis in relation to a fixed frame () by deformation caused by stretching and contracting of piezoelectric elements. Actuators (), which are a pair of members, are disposed one on either side of a mirror () in the Y-axis direction, and oscillate the mirror () about the Y axis in relation to the movable frame () by deformation caused by stretching and contracting of the piezoelectric elements. The length of each actuator () extending in the Y-axis direction is longer than a distance between an inner side of the fixed frame () to which the actuator () is connected and the middle point of an outer side of the movable frame () in the Y-axis direction.

Movable reflective element and two-dimensional scanning device

A mirror with a reflective layer formed thereon is supported within a frame-shaped support by two U-shaped arms. A plate-like arm connects fixation points (Q, Q), and a plate-like arm connects fixation points (Q, Q). A pair of piezoelectric elements (E, E) disposed along a longitudinal axis (L) on an upper surface of an outside bridge of the arm, and a single piezoelectric element (E) disposed along the longitudinal axis (L) on the upper surface of an inside bridge. Similarly, a pair of piezoelectric elements (E, E) disposed on an upper surface of an outside bridge of the arm, and a single piezoelectric element (E) disposed on the upper surface of an inside bridge. When a positive drive signal is applied to the piezoelectric elements (E, E, E, E) and a negative drive signal is applied to the piezoelectric elements (E, E), the mirror is displaced efficiently.

Growing community of inventors

Ogori, Japan

Yoshifumi Ikeda