Ricoh Company, Ltd.

Akitoshi Mochida

Tomohiko Kamatani

A light deflector includes a reflector having a reflection plane, a pair of movable parts that support the reflector, a supporting unit configured to support the pair of movable parts, a piezoelectric drive circuit provided for the pair of movable parts, the piezoelectric drive circuit being configured to drive the reflector in response to waveform of driving voltage, and circuitry configured to output two different driving voltages to the piezoelectric drive circuit. Each one of the two different driving voltages has waveform, and the waveform of each one of the two different driving voltages includes, in one cycle, a step-up period where voltage increases, a step-down period where voltage decreases, a first constant-voltage period where voltage is constant after the step-up period and before the step-down period, and a second constant-voltage period where voltage is constant before the step-up period and after the step-down period.

Light deflector, image projection apparatus, vehicle, and adjusting method

A light deflection device includes a reflector; a drive beam supporting the reflector such that the reflector is movable; a supporting section supporting the drive beam; and a piezoelectric drive circuit disposed on the drive beam. The light deflection device further includes circuitry configured to output a first drive-voltage waveform and a second drive-voltage waveform to the piezoelectric drive circuit. The first drive-voltage waveform has a period of a positive slope within one cycle, the period of the positive slope includes a period of a first slope and a period of a second slope different from the first slope. The second drive-voltage waveform has a period of a negative slope within one cycle, and the period of the negative slope includes a period of a third slope and a period of a fourth slope different from the third slope.

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Osaka, Japan

Akitoshi Mochida