| 摘要 |
PROBLEM TO BE SOLVED: To provide a magnetic shield type loudspeaker with a simple structure and to increase a magnetic force for driving a diaphragm by effectively utilizing a magnetic force of a magnet. SOLUTION: This loudspeaker has a pot-shaped yoke 20 consisting of a bottom face yoke 20a and a sidewall yoke 20b, a first ring-shaped magnet 21, a yoke 22 arranged on the magnet 21 and where a center pole 22a and a flange 22b are integrated, a second ring-shaped magnet 23 magnetized in the same direction as the first ring-shaped magnet 21, a first plate 24 which forms a first magnetic space 25 between the inner peripheral surface of the plate 24 and the outer peripheral surface of the center pole on the second ring- shaped magnet 23, a third ring-shaped magnet 26 magnetized in a direction opposite to the first ring-shaped magnet 21 on this plate, and a second plate 27 which is arranged on the third magnet so as to form a magnetic space 28 between the inner peripheral surface of the plate 27 and the outer peripheral surface of the center pole 22a and whose outer peripheral part is continuous with the upper parts of the side wall yoke of the pot-shaped yoke. Both the first and the second magnetic space 25 and 28 or either of them drive a diaphragm.
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