| 摘要 |
PROBLEM TO BE SOLVED: To enable piston vibration by arraying a plurality of small-sized and thin-shape speaker units on diaphragms of respective unit surfaces, in an indirectional speaker for approximating a sphere sound source with a dodecahedron comprised of regularly pentagonal unit surfaces, and performing full-surface driving to exclude partial vibration.SOLUTION: A speaker unit of each unit surface includes a plate-like magnetic circuit forming a plurality of annular magnetic gaps and a plurality of voice coils carried by a film-like diaphragm while being opposed to the magnetic gaps. In a development nearest to a straight line of twelve unit surfaces. all the voice coils are connected in series, from the first voice coil of the first unit surface to one end of the 72nd C-shaped voice coil of the twelfth unit surface, in one of bisected voice coils within each unit surface, and from the other end of the C-shaped voice coil to the first voice coil and by sequentially connecting, within one stroke, the other of the bisected voice coils. A signal line is attached to the first voice coil, a concatenation side of each unit surface is bent and adjacent sides are connected to provide a dodecahedron. |
