| 摘要 |
PROBLEM TO BE SOLVED: To solve a matter that the radius of a roll portion must be increased in order to increase the vertical amplitude of a damper but since the shape of the roll itself increases stiffness when the radius of the roll portion is increased it becomes difficult to achive with a damper of small diameter, and to solve a problem when a means for increasing the roll partially is employed that vertical asymmetry worsens or stress concentrates on the increased roll portion and thereby the risk of destruction due to fatigue caused by vertical amplitude becomes high. SOLUTION: The damper formed of at least two roll portions is provided with an elastic body at least on one side or both sides or in the material of outer circumferential portion including the movable portion of the damper. Consequently, resonance is reduced at the roll portion of the damper without reducing sound pressure and since characteristics of good linearity are imparted, a speaker of high sound quality is achieved. COPYRIGHT: (C)2008,JPO&INPIT
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