Variable frequency buzzer assembly
US6215391A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 22, 1999 |
| Grant date | Apr 10, 2001 |
| Priority date | — |
| Expiry date | Oct 22, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10K9/20
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
A buzzer assembly for a personal communications device changes geometry in order to emit sounds at a variety of frequencies at an approximately constant volume, such as for playing melodic alerts. The buzzer assembly incorporates a buzzer and gasket to create an air chamber with an associated acoustic impedance. A translational actuator moves a portion of either the buzzer or gasket, depending on the particular embodiment, to change the air volume and thus the associated acoustic impedance. By changing the acoustic impedance, the resonant frequency of the buzzer assembly is changed. When the buzzer is then operated at or near resonant frequency corresponding to the then-current acoustic impedance, the sound generated by the buzzer assembly is louder. By changing the resonant frequency of the buzzer assembly in this manner to correspond to the frequency of the tone to be generated, the sound volume generated by the buzzer assembly can be made approximately constant across a broader frequency range than is possible with conventional buzzer designs, such as 3 kHz or larger.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.