| 摘要 |
PROBLEM TO BE SOLVED: To provide a small-sized and light bone conduction type receiver capable of obtaining a sufficient output level in a low frequency region even when used in the state of opening the external acoustic meatus. SOLUTION: A first acoustic vibration generation source 2A and a second acoustic vibration generation source 2B are provided on both end parts of an arm part 1 which is an elastic body configured such that both ends can be brought into press contact with the periphery of the external acoustic meatus entrance of a human body by elastic force and bent in arcuate shape. A third acoustic vibration generation source 3 is provided on the center part of the arm part 1. The resonance frequency of a vibration system including the third acoustic vibration generation source 3 and the arm part 1 is set to be lower than the resonance frequency of the first and second acoustic vibration generation sources 2A and 2B. Also, at least the center part of the arm part 1 is in a belt shape, and the third acoustic vibration generation source 3 is a piezoelectric bimorph formed by bonding a piezoelectric ceramic to the part of the belt shape. COPYRIGHT: (C)2008,JPO&INPIT
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