Mitsumi Electric Company Ltd.

Takahiko Nishiyama

Tsukasa Yamada

Toyoki Tanaka

Soumei Takahashi

Yoichi Sakaue

An optical scanning device includes an optical scanner including a mirror that includes a light reflection surface, a driving source that causes the mirror to rotate around a rotation axis passing through the center of the light reflection surface in response to a driving signal, and a piezoelectric sensor that outputs a sensor signal corresponding to a rotational angle of the mirror around the rotation axis; and an impedance conversion circuit that receives the sensor signal from the piezoelectric sensor, performs impedance conversion on the received sensor signal, and outputs the impedance-converted sensor signal.

Optical scanning device and head-up display

An optical scanning device includes a mirror part including a mirror reflecting surface to reflect incident light, a pair of torsion bars configured to support the mirror part from both sides and configured to form a first axis around which to swing the mirror part by a torsional motion thereof so as to deflect the reflected light, and at least one stress alleviation area configured to alleviate a stress generated by the torsional motion of the torsion bars. The alleviation area is provided between an intersection of a second axis perpendicular to the first axis and passing through the center of the mirror reflecting surface and an edge of the mirror reflecting surface, and at least one of the torsion bars.

Optical scanning device

An optical scanning device includes a mirror part including a mirror reflecting surface to reflect incident light, a pair of torsion bars configured to support the mirror part from both sides and configured to forma first axis around which to swing the mirror part by a torsional motion thereof so as to deflect the reflected light, and at least one stress alleviation area configured to alleviate a stress generated by the torsional motion of the torsion bars. The alleviation area is provided between an intersection of a second axis perpendicular to the first axis and passing through the center of the mirror reflecting surface and an edge of the mirror reflecting surface, and at least one of the torsion bars.

A driving device includes an electro-mechanical transducer having first and second end portions opposite to each other in an expansion/contraction direction, a stationary member coupled to the first end portion of the electro-mechanical transducer, a vibration friction portion mounted to the second end portion of the electro-mechanical transducer, and a moving portion frictionally coupled to the vibration friction portion, whereby moving the moving portion in the expansion/contraction direction of the electro-mechanical transducer. The moving portion is driven by equalizing a constant expanding speed of the electro-mechanical transducer with a constant contracting speed of the electro-mechanical transducer and by setting a constant rest time interval after one of contraction of the electro-mechanical transducer and expansion of the electro-mechanical transducer.

Method of driving a driving device

A driving device includes an electro-mechanical transducer having first and second end portions opposite to each other in an expansion/contraction direction, a stationary member coupled to the first end portion of the electro-mechanical transducer, a vibration friction portion mounted to the second end portion of the electro-mechanical transducer, and a rod-shaped moving portion frictionally coupled to the vibration friction portion, whereby moving the moving portion in the expansion/contraction direction of the electro-mechanical transducer. The stationary member consists essentially of a base alloy which consists of, by weight, 88 to 97% tungsten, 2 to 11% nickel as a binder, and, as the balance, 0.1 to 2% at least one metal having an ionization tendency which is higher than that of tungsten. The stationary member has a surface without nickel plating.

Driving device having suitable stationary member as material

A driving device includes an electro-mechanical transducer having first and second end portions opposite to each other in an expansion/contraction direction, a static member coupled to the first end portion of the electro-mechanical transducer, a vibration friction portion coupled to the second end portion of the electro-mechanical transducer, and a rod-shaped moving portion frictionally coupled to the vibration friction portion, whereby moving the moving portion in the expansion/contraction direction of the electro-mechanical transducer. An outer sheath is for covering the driving device. An attitude retaining arrangement retains an attitude of the driving device with respect to the outer sheath.

Driving device capable of improving a shock and vibration resistance thereof

A driving device includes an electro-mechanical transducer having first and second end portions opposite to each other in an expansion/contraction direction, a static member coupled to the first end portion of the electro-mechanical transducer, a vibration friction portion coupled to the second end portion of the electro-mechanical transducer, and a rod-shaped moving portion frictionally coupled to the vibration friction portion, whereby moving the moving portion in the expansion/contraction direction of the electro-mechanical transducer. The driving device is covered with a cabinet. An elastic member lies between the cabinet and the static member.

Driving device capable of obtaining a stable frequency characteristic

A driving device includes an electro-mechanical transducer having first and second end portions opposite to each other in an expansion/contraction direction, a stationary member coupled to the first end portion of the electro-mechanical transducer, a vibration friction portion coupled to the second end portion of the electro-mechanical transducer, and a rod-shaped moving portion frictionally coupled to the vibration friction portion, whereby moving the moving portion in the expansion/contraction direction of the electro-mechanical transducer. The vibration friction portion is made of a material having a vibration transfer rate of 4900 meters/second or more. The moving portion is made of a material which has a vibration transfer rate of 4900 meters/second or more and which is different from that of the vibration friction portion.

Driving device capable of transferring vibrations generated by an electro-mechanical transducer to a vibration friction portion with a high degree of efficiency

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Kanagawa, Japan

Takahiko Nishiyama