Sound output device for lamp and lamp system including the same
AssigneeHyundai Mobis Co., Ltd.
InventorMyeong Je KIM
Life of this patent
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Abstract
The present invention relates to a sound output device for a lamp and a lamp system including the same, and more particularly, to a device including a piezoelectric element stack including a plurality of piezoelectric elements stacked together, a sound driving circuit configured to drive the piezoelectric element stack, and a signal processing circuit connected between the sound driving circuit and the piezoelectric element stack, wherein the signal processing circuit includes an impedance compensation filter configured to compensate for an impedance of the piezoelectric element stack that varies according to an output of the sound driving circuit, and the impedance compensation filter includes reactance components excluding resistive elements.
Claims19
A sound output device for a lamp, comprising:
- a piezoelectric element stack comprising a plurality of piezoelectric elements stacked together;
- a sound driving circuit configured to drive the piezoelectric element stack;
- and
- a signal processing circuit connected between the sound driving circuit and the piezoelectric element stack,
- wherein the signal processing circuit comprises an impedance compensation filter configured to compensate for an impedance of the piezoelectric element stack that varies according to an output of the sound driving circuit, and the impedance compensation filter comprises reactance components excluding resistive elements.
A lamp system comprising:
- a lamp housing;
- an outer lens coupled to the lamp housing;
- a piezoelectric element stack attached to the outer lens or the lamp housing, the piezoelectric element stack comprising a plurality of stacked piezoelectric elements and configured to vibrate the outer lens or the lamp housing to output sound;
- and
- a driving circuit coupled to the piezoelectric element stack via an impedance compensation circuit that includes only reactance components and is configured to prevent overcurrent in the piezoelectric element stack.
Dependencies are inferred from the claim text.