Pioneer Electronic Corporation

Tohoku Pioneer Electronic Corporation

Tsunehiro Tsukagoshi

Shinichi Yokozeki

Toshikazu Yoshino

Yasuyuki Arai

Sumio Hagiwara

Masataka Uchidoi

Masami Kimura

Teruo Tohma

Kunio Imai

Masahiko Naoe

Takashi Ujihara

Hiroshi Ito

Teruo Toma

Isao Yamamuro

Teruo Touma

Etsuro Nemoto

Kazuyoshi Kobayashi

Shin-ichi Suzuki

Hitomi Ogino

Shinichi Yokozseki

A vibrating diaphragm is disposed in a magnetic gap. The diaphragm comprises two organic films superimposed on each other, and two metal films overlaid on the organic films, respectively. One of the organic films has a smaller polarization and the other organic film has a large polarization. Both metal films are different in work function, and electrically connected by a metal film. Electric current is supplied to the vibrating diaphragm to vibrate it.

Ribbon speaker

An insulator substrate is held by a supporting member in an upright position. A plurality of heating members are formed on a top face of the substrate. A plurality of individual conductive patterns and a common electrode are provided on the substrate to be connected to the heating members so as to supply a current to each heating member.

Thermal head for a thermal printer

A photomagnetic memory medium of an amorphous thin film of a rare-earth transition metal alloy of non-columnar structure deposited on a substrate. In order to achieve the non-columnar structure, the alloy is sputtered in the presence of a plasma but the plasma is confined by a magnetic field so as not to touch the substrate. The alloy is preferably TbFeCo.

Photomagnetic memory medium having a non-columnar structure

An acoustic diaphragm formed of beryllium or an alloy composed mainly of beryllium. Said diaphragm has a crystal structure having its plane (1120) preferentially orientated in parallel with the surface of the diaphragm.

Acoustic diaphragm

A molding composition is obtained by blending flaky graphite with a resin component comprising a mixture of a thermoplastic resin having a glass transition temperature higher than room temperature and another thermoplastic resin having a glass transition temperature lower than room temperature. The composition is kneaded and rolled into a sheet to orient the graphite flakes parallel to the surface of the sheet. The rolled sheet is then molded into an article, for example, speaker diaphragm, arm pipe and head shell, which may be optionally be carbonized or graphitized. The resulting article exhibits improved physical properties, especially high specific modulus of elasticity comparable to aluminum and beryllium as well as good internal loss comparable to paper.

Molding compositions and diaphragms, arm pipes and head shells molded

An acoustic vibrating element, such a domed speaker diaphragm A or a phonographic pickup cantilever B, is formed by vapor deposition on an easily separable mold member 5 of tantalum or tantalum alloy when a mixture of a hydrocarbon gas and an inert gas is passed through a furnace heated to a temperature of 1150.degree. C.-1250.degree. C. at a flow rate in excess of 200 cm/min. The c-axis crystalline orientation of the resulting graphite element is substantially perpendicular to its surface, which provides a Young's modulus above 16,000 Kg/cm.sup.2.

Acoustic vibrating element of graphite and method of manufacturing same

Elements for a tone-arm system such as arm pipes, head shells, cartridge bodies, and arm bases are fabricated from a kneaded mixture comprising polypropylene and flaky graphite powder. The mixture may further include polymethyl methacrylate and/or rubber-like material. Graphite flakes are preferably oriented parallel to the surface of the element. The elements show improved temperature resistance.

Tone-arm elements

Vibratory elements for use in audio equipment are fabricated from a kneaded mixture comprising polypropylene and flaky graphite powder. The kneaded mixture is rolled into a sheet in which graphite flakes are oriented parallel to the surface, and the sheet is then formed into a desired shape, for example, a dome- or cone-shaped diaphragm and a cantilever, as by vacuum forming, air-pressure forming or press molding. The mixture may further include polymethyl methacrylate and/or rubber-like material. The elements are characterized by improved temperature resistance.

Vibratory elements for audio equipment

A honeycomb shaped diaphragm for use in acoustic instruments such as speakers is manufactured by kneading a mixture of flaky graphite powder and thermoplastic resin, preferably polyvinyl chloride, rolling the mixture into a plate, forming honeycomb recesses in the plate, and mating two recessed plates with each other so that the corresponding recesses form closed cavities. The formed plate may be carbonized before assembly. The resultant diaphragm shows a high Young's modulus, a low apparent density and a remarkably high specific modulus of elasticity ensuring improved acoustic characteristics.

Diaphragm for acoustic instruments and method of manufacturing the same

Vibratory elements for use in audio equipment are fabricated from a kneaded mixture comprising post-chlorinated polyvinyl chloride and flaky graphite powder. The kneaded mixture is rolled into a sheet in which graphite flakes are oriented parallel to the surface and the sheet is then formed into a desird shape, for example, a dome- or cone-shaped diaphragm and a cantilever, as by vacuum forming, air-pressure forming or press molding. The mixture may further include polymethyl methacrylate and/or rubber-like material. The elements are characterized by improved temperature resistance.

A molding composition comprising a thermoplastic resin in admixture with flaky graphite and carbon black is molded into an acoustic article which shows a high specific modulus of elasticity due to graphite and an increased internal loss due to carbon black. Preferred molding compositions contain 10-90 wt % of polyvinyl chloride or a vinyl chloride-vinyl acetate copolymer and 90-10 wt % of graphite flakes plus carbon black submicron particles. Carbon black is present in an amount of 0.1-2 parts per part of flaky graphite. Speaker diaphragms, arm pipes and head shells are fabricated from the molding composition. The composition is kneaded and rolled to orient the graphite flakes, and subsequently molded into an article, which is then optionally carbonized or graphitized.

A head shell for a record player tonearm comprises a composite material essentially consisting of a thermoplastic resin and graphite powder. The composite material is prepared by kneading the components, rolled to impart a degree of orientation to the graphite powder particles, which are in the form of flaky graphite and then molded into a shell, along the surface of which the graphite particles are oriented. Head shells wherein the composite material is oxidized at the surface and head shells wherein the composite material is carbonized or graphitized are also included. A light weight, rigid head shell having a high specific modulus of elasticity is obtained through a simple procedure at low cost.

Head shell for record player tonearms

An arm pipe for a record player tonearm comprises a composite material essentially consisting of a thermoplastic resin and graphite powder. The composite material is prepared by kneading the components, rolled to impart a degree of orientation to the graphite powder particles, which are in the form of flaky graphite and then molded into a pipe, along the surface of which the graphite particles are oriented. Arm pipes wherein the composite material is oxidized at the surface of the pipe and arm pipes wherein the composite material is carbonized or graphitized are also included. A light weight, rigid arm pipe having a high specific modulus of elasticity is obtained through a simple procedure at low cost.

Arm pipe for record player tonearms

A vibrating member made of a thin metal plate and adapted to be used in an acoustic transducer such as a loudspeaker or microphone is diffused at least partially with an inorganic substance to improve the acoustic characteristics thereof, particularly the high frequency range.

Vibrating member for acoustic transducer and method for manufacturing

A method of producing a diaphragm of an acoustic instrument having the steps of blending powders of carbon such as graphite, carbon black or the like and a thermoplastic or a thermosetting resin, shaping the resultant blend into a desired form and then carbonizing the shaped blend. As a result, it has become possible to produce a diaphragm of an acoustic instrument, having a light weight, high rigidity and a large ratio of Young's modulus to density.

Growing community of inventors

Tokyo, Japan

Tsunehiro Tsukagoshi