Star Micronics Company Limited

Naohiro Fujinami

Hajime Kitamura

Shigeru Sugiyama

Yoshio Imahori

Tomoyuki Sato

Fuminori Moritake

Hitoshi Yamashima

Hisashi Kubota

Katsuyoshi Omori

Masami Kushida

The diaphragm is supported by the frame at the outer edge thereof. The pair of terminal members is mounted on the frame, and a pair of lead wire drawn from the voice coil is fixed to the land portion of the terminal member for electrical continuity. Since the land portion is disposed on the upper side of the frame, fixation of the lead wire can be performed without turning the frame upside down. This simplifies the manufacturing process of the speaker and also prevents a breakage of the lead wire that conventionally happens when the frame is turned upside down. Further, this prevents the operator from touching the lead wire since no part of the lead wire is exposed outside the frame after the fixation.

Speaker

A pair of lead wire drawn from a voice coil is fixed to a land portion of a pair of terminal member by thermo-compression bonding. The pair of terminal member is integrally formed with the frame by insert molding. The frame made of synthetic resin has a pair of circular holes on the back side of the land portion to expose the land portion to the back space of the frame. In thermo-compression bonding, a supporting jig is pressed against the back side of the land portion via the circular hole. Thereby, generated heat is immediately transmitted to the supporting jig, preventing melting part of the frame around the land portion. Pressing force of a thermo-compression jig is received by the supporting jig, preventing sinking of the land portion in the frame.

Fixing of a voice coil ( ) to a diaphragm ( ) is performed by caulk-fixing a coil supporting member ( ) to the diaphragm ( ) and by fit-supporting the voice coil ( ) by the coil supporting member ( ). Hereby, the voice coil is physically fixed to the diaphragm ( ) and its fixing strength is heightened. The caulk-fixing is performed by subjecting a caulking projection of the coil supporting member ( ) to a plastic deformation thereby to provide a caulk-fixed portion ( ), whereby deformation injurious to the acoustic property does not occur in the diaphragm ( ). Further, the fit-supporting is performed by interposing a flange portion ( ) formed at an upper end portion ( ) of the voice coil ( ) between an engaging portion ( ) of the coil supporting member ( ) and a central flat portion ( ) of the diaphragm ( ) and holding it by them from upper and lower sides.

A frame ( ) supporting a diaphragm ( ) by its outer periphery is constructed by a connecting ring ( ) and a base ( ) which comprises a bottomed cylinder portion ( A) and a mounting portion ( B) which extends radially outward from the bottomed cylinder portion ( A) which is a part of the magnetic circuit unit ( ). The connection is achieved by the caulking of the ring ( ) and the mounting portion ( B) with the diaphragm ( ) clamped therebetween.

By forming a flange portion ( ) protruding inward in the radial direction at an upper end portion ( ) of a voice coil ( ), a coiling sectional shape of the voice coil ( ) is set to a L-shape. And, the upper end portion ( ) of this voice coil ( ), is bonded and fixed to a central flat portion ( ) of a diaphragm ( ). Hereby, by only increasing slightly the weight of the usual voice coil having an I-shaped coiling section, the large bonding area can be obtained between the voice coil ( ) and the diaphragm ( ), so that separation of the voice coil ( ) can be prevented. Further, since other portions of the voice coil ( ) than the upper end portion ( ) thereof have the usual coil thickness, it is not necessary to expand the width of a cylindrical magnetic gap G in a magnetic circuit unit ( ), whereby it is prevented that electroacoustic conversion efficiency of a speaker ( ) lowers.

Upon receipt of a direction indication control signal s , a sounding-body driving circuit generates a driving signal s for generating a flashing operation sound which is an artificial striking sound similar to a striking sound of a mechanical relay. The driving signal s is output to a speaker via an amplifier , and the flashing operation sound is outputted from the speaker , thereby obtaining the flashing operation sound which does not sound unusual to the driver. The sounding-body driving circuit enables a plurality of rectangular wave signals having the same amplitude and different frequencies to be synthesized in sequence of time by first and second synthetic signal generating circuits A and B to thus generate first and second synthetic signals s and s as artificial striking sounds.

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Shizuoka, Japan

Naohiro Fujinami