Denso Ten Limited

Fujitsu Ten Limited

Keiichiro Tanaka

Masahiko Kubo

Shigeki Kato

A speaker device according to an embodiment includes a panel, a plurality of vibration elements, and a driving unit. The plurality of vibration elements vibrate the panel. The driving unit applies, to a first vibration element, a first driving signal that includes a modulated wave provided in such a manner that a carrier wave in an ultrasonic wave band is modulated by a sound signal in an audible wave band and applies, to a second vibration element, a second driving signal that includes the carrier wave and is different from the first driving signal, so that a vibrational region is formed on the panel.

Speaker device and control method for a speaker device

A speaker apparatus according to an embodiment includes a panel, one or more vibration elements, a drive unit, and a reflection part. The one or more vibration elements vibrate the panel. The drive unit applies a driving signal to the one or more vibration elements to form a striped vibration region on the panel. The driving signal is obtained by modulating a carrier wave of an ultrasonic band by a sound signal of an audible frequency band. The reflection part reflects at least one of first and second ultrasonic waves, which are generated from the vibration region and advancing in respective different directions, so as to bring an advancing direction of the first ultrasonic wave and that of the second ultrasonic wave close to each other.

Speaker apparatus including a panel and vibration elements

An audio amplifier and a warning sound amplifier are connected in parallel to each other, relative to a voice coil of a loudspeaker. A resistor having an impedance greater than an impedance of the voice coil is connected to the voice coil and is also connected to the warning sound amplifier. An audio signal from the warning sound amplifier is input to the voice coil via the resistor. Thus, since the warning sound amplifier is connected to the resistor having the impedance greater than the impedance of the voice coil of the loudspeaker, even in a case where only the audio amplifier is operated, a large current is prevented from flowing into the warning sound amplifier.

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Kobe, Japan

Keiichiro Tanaka