Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Other

Shinya Tabata

Takashi Suzuki

Shinya Mizone

Yoshiyuki Takahashi

Kiyoshi Ikeda

Hiroko Yamazaki

Hiroyuki Takewa

Mitsukazu Kuze

Satoshi Koura

Toshihiro Shimizu

Masaharu Takada

Mikio Iwasa

Shinji Okuda

Hidekazu Tanaka

Teruo Doi

Michitaka Oda

Yasuhiro Nakanishi

Yukio Sone

Takenori Yamakawa

A loudspeaker includes the following components: a frame () that has a magnetic circuit () including a magnetic gap () therein; and a diaphragm () that is bonded to a voice coil () fitted into the magnetic gap () in the center thereof, and to the periphery of the frame () along the outer periphery thereof. The magnetic circuit () includes a yoke (), a magnet (), and a top plate (). Tongue-shaped flanges () are disposed at a substantially equidistant spacing in three positions to protrude from the top end face of the yoke (). The total area of these tongue-shaped flanges () in the three positions does not exceed a half of the total area corresponding to the flange part without flanges (). The frame () also includes engaging parts () each for receiving one of the tongue-shaped flanges () therein.

Loudspeaker

The present invention provides a loudspeaker including an edge formed in such manner that a thickness of a sectional shape in a radial direction increases from an inner peripheral portion toward an outer peripheral portion. Due to this structure, a mechanical impedance of the edge against a diaphragm is decreased and bad influences on a vibration mode of the diaphragm are suppressed, and also, vibration energy is absorbed by a thick portion of the outer peripheral portion, thereby suppressing standing waves of the diaphragm.

Loudspeaker edge

A speaker diaphragm edge obtained by hot-forming into a desired edge shape, a resin-treated base material, which was prepared by using a silkscreen printing technique to apply a shaping agent layer only to the necessary portion of a base material.

Speaker diaphragm edge and its manufacturing method

A diaphragm is gained by the co-molded of a dome part, a voice coil junction part, a cone part and a peripheral part through the injection mold of thermoplastic resin. The thickness of the central part of the dome is made great so that the resonance amplitude in this part becomes small. In addition, an annular rib is integrally provided to the voice coil junction part so as to increase the junction strength between the diaphragm and the voice coil bobbin. Thus, the electromagnetic driving force of the voice coil can be effectively transmitted to the diaphragm so that a loud speaker with excellent characteristics can be gained.

Loud speaker, diaphragm and process for making the diaphragm

A speaker edge is made of a thermosetting composition consisting of a polyurethane prepolymer and an inactivated solid polyamine as a latent hardener. A gas is dispersed in the thermosetting composition, prior to feed into a mold, so that it can foam and solidify to give the speaker edge. In a method of making the speaker edge, the composition will be injected into a female mold segment heated below the critical thermosetting temperature, foaming the composition. Then placed in the female segment is a male segment heated above the critical temperature, causing the ingredients to react with each other to solidify in the mold. An apparatus for making the speaker edge from the composition has: a device for intake of a gas, another device for injecting the composition into the gas, another device for mechanically dispersing the gas throughout the composition, still another device for injection of this gas-containing composition into a female mold segment, a further device for placing a male segment in the female segment, and a still further device for solidifying the composition, while foaming it.

Speaker edge, method of foam-molding the same, apparatus for foam-molding the same, speaker edge foam-molding system, and speaker employing the speaker edge

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Mie, Japan

Shinya Tabata