Kabushikikaisha Kenwood

Toyo Boseki Kabushiki Kaisha

Trio Kabushiki Kaisha

Namiki Precision Jewel Co., Ltd.

Shuhei Ohta

Shiro Iwakura

Hiroaki Toshima

Kaoru Yamazaki

Masakatsu Sakamoto

Yoichi Yaguchi

Tsugio Sato

Yoshio Sakamoto

Yoshikazu Shirasaki

Ichiro Yoshida

Masakatu Sakamoto

A high performance loudspeaker structure is provided which is of reduced thickness yet resistible to large vibration amplitudes. A repulsion magnetic circuit is formed by two magnets with the same poles being faced each other and a center plate interposed between the two magnets. The repulsion magnetic circuit is held in position by two frames. A diaphragm is mounted at the level flush with the center of the winding width of a voice coil. The outer periphery of an edge (suspension) bonded to the outer circumference of the diaphragm is held by flanges of the frames.

Loudspeaker structure

A speaker diaphragm is formed by heat-pressurized molding a composite structure of fabric cloth and resin sank into the fabric cloth. The fabric cloth is woven from high strength and high elasticity polyethylene fiber which has at least tensile modulus of 4,500 kg/mm.sup.2 (500 g/d).

Speaker diaphragm

A method of forming diamond-like carbon layer which is advantageously adaptable as a coating layer on acoustic diaphragms. In the method, carbon vaporized out of solid carbon source is deposited onto the surface of the diaphragm as the coating layer in the atomosphere of catalystic gas, for instance, H.sub.2 +Ar or H.sub.2 of about 10.sup.-4 Torr. The deposited carbon layer on the surface of the diaphragm is an amorphous carbon of inclusion of hybridized orbital SP.sup.2 bond and hybridized orbital SP.sup.3 bond and crystalline carbon particles of hybridized orbital SP.sup.3 bond dispersed in the amorphous carbon, or an amorphous carbon of inclusion of hybridized orbital SP.sup.2 bond and hybridized orbital SP.sup.3 bond.

Method for forming a hard carbon thin film on article and applications

A method of forming diamond-like carbon layer which is advantageously adaptable as a coating layer on acoustic diaphragms. In the method, carbon vaporized out of solid carbon source is deposited onto the surface of the diaphragm as the coating layer in the atmosphere of catalystic gas, for instance, H.sub.2 +Ar or H.sub.2 of about 10.sup.-4 Torr. The deposited carbon layer on the surface of the diaphragm is an amorphous carbon of inclusion of hybridized orbital SP.sup.2 bond and hybridized orbital SP.sup.3 bond and crystalline carbon particles of hybridized orbital SP.sup.3 bond dispersed in the amorphous carbon, or an amorphous carbon of inclusion of hybridized orbital SP.sup.2 bond and hybridized orbital SP.sup.3 bond.

Growing community of inventors

Hachiohji, Japan

Shuhei Ohta