Pioneer Electronic Corporation

Pioneer Corporation

Tohoku Pioneer Corporation

Takashi Ohyaba

Shunichi Takahashi

Shinji Koyano

Takanobu Saito

Shouichiro Terauchi

Tatsuya Ando

Katsutoki Hanayama

Hiroyuki Kobayashi

Hiroyuki Dohi

Haruo Okada

Satoshi Kumada

Tomohiro Suenaga

Teruo Baba

Shozo Kinoshita

Yoko Sato

Junko Oba

Kohshiro Kogure

Yuichi Mohri

Yoshiya Usami

Ziging Zhang

Tohru Nagatani

Hiroyuki Kataoka

Takashi Morishige

Yoichi Suzuki

Minoru Kamishima

Makoto Sakakibara

Tetsuo Kawamura

Showichiro Terauchi

Koushirou Kogure

Hiroaki Matsuhisa

An internal magnetic circuit is formed by a plate forming a pole piece, a vertically magnetized magnet attached to a bottom face of the plate, and a yoke attached to a bottom face of the magnet. A magnetic gap is formed between the plate and the yoke. The yoke includes a bottom part attached to the bottom face of the magnet, a side part standing on the side of the plate, and a folded-back part folding downwards over the side part to face the magnetic gap. Thus, the internal magnetic circuit having a uniform magnetic flux density inside the magnetic gap along the direction of its length is provided.

Internal magnetic circuit and loudspeaker system incorporating the same

An audio device has an electroacoustic transducer mounted on a clamp for converting an electric signal into an acoustic signal, an electromechanical vibration transducer for converting the electric signal into a mechanical vibration, and an abutting member having the electromechanical vibration transducer therein and mounted on the clamp so that the electromechanical vibration transducer is contacted with a cervix of a user when the audio device is worn on the head of the user.

Acoustic device

A speaker apparatus has a damper for supporting vibrating elements including a vibrating diaphragm. The damper is formed by injecting a predetermined amount of a resin material into a metal mold of an injection molding equipment.

Damper for a speaker apparatus

A cylindrical frame is mounted in a cabinet and a magnetic circuit is provided at an end of the frame. A diaphragm having a peripheral free edge is connected to a coil bobbin and a cylindrical ring is secured to the free end edge and disposed in a cylindrical supporting portion of the frame. An annular sealing member is secured to the cylindrical ring so that an outside peripheral wall thereof is slidably contacted with an inside wall of the cylindrical supporting portion of the frame.

Surroundless loudspeaker

A duct is provided in a cabinet for radiating sound pressure emitted from a speaker unit. The duct comprises a first duct and a second duct. The first duct extends in a direction perpendicular to a radiating direction of the sound pressure radiated from a front side of the speaker unit. The second duct is connected to an end of the first duct. An inner end of of the second duct is communicated with the cabinet. The speaker unit is disposed at a connection of the first and second ducts.

Speaker system

A dynamic loudspeaker unit having a voice coil formed with two windings in which a capacitor is connected in series to a parallel circuit, one circuit arm being composed of a series circuit of one of the two windings and an inductor and the other circuit arm being composed of the remaining winding. The dynamic loudspeaker unit thus constructed is housed in a bass-reflex type cabinet, whereby a shoulder characteristic having a large Q in a bass zone can be obtained, and due to a combination of the inductor and the capacitor, a desired lowest resonance frequency lower than an actual lowest resonance frequency can be selected. Thus, the reproducible bass range can be extended.

Loudspeaker system

The ribbon-type loudspeaker that has the characteristics of large cooling effect such that electrical input power is increased. The ribbon-type loudspeaker comprises magnet means having plates positioned in facing relation to each other to form a gap therebetween; an electrically conductive diaphragm extended between said plates to complete a magnetic circuit, said diaphragm forming an electric circuit transversely of said magnetic circuit, at least one side of said diaphragm being formed with an electrically insulating layer; and a heat absorbing plate extended between said plates and attached in contacting relation thereto over an extended area, said heat absorbing plate being formed with an electrically insulating layer in facing relation to the electrically insulating layer of the diaphragm.

Ribbon-type loudspeaker

Growing community of inventors

Saitama-ken, Japan

Takashi Ohyaba