| 摘要 |
PROBLEM TO BE SOLVED: To obtain a sound image having an extent extensively over a wide range, by abutting a transmitter transmitting a displacement output from an actuator against an acoustic diaphragm, and exciting the acoustic diaphragm with vibration component in at least the face direction. SOLUTION: In a loudspeaker device, a driving rod 103a for the actuator 103 is abutted against the end face on the lower-end side of a pipe 102. The actuator 103 excites the pipe 102 by the vibration component in the direction (face direction) orthogonal to the end face on the lower-end side of the pipe 102 from the end face. The end face on the lower-end side of the pipe 102 is excited by longitudinal waves, and elastic waves (vibrations) are propagated gradually in the face direction on the pipe 102. The mode conversion of longitudinal waves, transverse waves, longitudinal waves and transverse waves is repeated, when the elastic waves are propagated on the pipe 102, and the mixed waves of longitudinal waves and transverse waves are obtained. Vibrations in the in-plane direction (direction vertical to a face) of the pipe 102 are excited by transverse waves, and sound waves are emitted. Large transverse waves are not generated at the excitation point of the pipe 102, and the sound waves from the excitation point will not be listened to as a sound that is very much larger than sound waves from other locations, thus obtaining the sound image having a sense of extent. COPYRIGHT: (C)2007,JPO&INPIT
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