Variably sound-absorbing device
US6075308A · kind A · utility
Assignees
Inventor
Key dates
| Filing date | Nov 25, 1998 |
| Grant date | Jun 13, 2000 |
| Priority date | — |
| Expiry date | Nov 25, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10K11/16
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
A variably sound-absorbing device comprises a piezoelectric material 32 the peripheral portion of which is fixed to a frame 31 or the like, at least one pair of electrodes 34 formed on opposite surfaces of the piezoelectric material, and at least one circuit element 36 through which the electrodes are connected to each other. The piezoelectric material 32 is boardlike and curved, and an electrical characteristic of the circuit element 36 (a circuit showing a negative capacitance for example) is variable. The modulus of elasticity (the real number part of the modulus of elasticity) and the loss factor (the imaginary number part of the modulus of elasticity) of the piezoelectric material are thereby varied and the sound-absorbing characteristic is electrically varied to a considerable extent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.