| 摘要 |
The speaker device (100, 200, 300) includes the magnetic circuit system (30) having an annular plate (3) and magnetic fluid (4), and a vibration system (31) having a voice coil bobbin (5) and a voice coil (6). When the speaker device is not driven, the voice coil (6) is located at a predetermined stationary position within the magnetic gap (9) filled with the magnetic fluid (4). Within the magnetic gap (9), a recess portion (60,5a,70) into which the greater part of the magnetic fluid (4) flows is formed in the voice coil (6) or voice coil bobbin (5). When the speaker device is not driven, the greater part of the magnetic fluid (4) enters the recess portion (60,5a,70) and forms a stable condition. Thereby, in the case where the edge is formed by soft material, the voice coil (6) is never affected by the buoyant force of the magnetic fluid (4) and reliably held at the predetermined stationary position within the magnetic gap (9). |
