| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an alarm speaker capable of maintaining a sound pressure while causing less change in physical properties, such as elastic modulus, even under a high temperature environment, and causing less deterioration of characteristics even when used for a long period of time. <P>SOLUTION: An alarm speaker 1 includes a speaker unit 3 which is housed in a housing 2, and outputs an alarm sound of a predetermined frequency band. The speaker unit 3 includes: a piezoelectric plate 31 that vibrates by piezoelectric effect according to a drive oscillation; and a diaphragm 32 driven by the piezoelectric plate 31. The diaphragm 32 is formed with aluminum. The housing 2 includes: sound holes 231 configured to output a sound wave outputted from the speaker unit 3 to outer space; and a cavity 211 that is space between the diaphragm 32 and the sound holes 231. <P>COPYRIGHT: (C)2013,JPO&INPIT |
