Pioneer Corporation

Tohoku Pioneer Corporation

Pioneer Electronic Corporation

Tohoku Pioneer Electronic Corporation

Other

Pioneer Electronics Corporation

Tohoku Pioneer Electronics Corporation

Masatoshi Sato

Satoshi Hachiya

Jiro Nakazono

Kunio Mitobe

Hiroyuki Tomiyama

Hiroyuki Kobayashi

Fumio Murayama

Koji Takayama

Yoshitaka Kobayashi

Takashi Suzuki

Masanori Ito

Shinichi Hayasaka

Shuichi Watanabe

Yoshimi Kudo

Shigeyuki Kousaka

Kouichi Honma

Yuichi Kasahara

Kazuhiko Saheki

Moriyuki Yokoyama

A Vibration system part for a speaker device includes a woven fabric or a non-woven fabric made of basalt fiber produced by twist yarn or roving yarn being a continuous long-fiber. The vibration system part for the speaker device may be a diaphragm, a center cap, an edge or a damper, for example. In a preferred example, the woven fabric or the non-woven fabric is impregnated with thermosetting resin or thermoplastic resin. Additionally, a lamination member, such as paper, foam material, resin or a film, is preferably laminated (coated) on the woven fabric or the non-woven fabric. Thus, the vibration system parts for the speaker device, having excellent acoustic property and reliability, can be obtained at a low price.

Vibration system part for speaker device and manufacturing method thereof

A method for manufacturing a diaphragm for use in an electroacoustic transducer in a multi-layer structure which includes a first diaphragm layer of synthetic resin molded in a predetermined shape by injection molding and a second diaphragm layer layered in intimate contact on the first diaphragm layer and made of substance different from the first diaphragm layer, includes executing successively a pre-molding step and an injection-molding step, thereby providing the multi-layer structure. The pre-molding step includes attaching a non-molded sheet-like material which is a raw material of the second diaphragm layer to a mating surface of one of the die part of an injection molding die, and closing thereafter the injection molding die to give the sheet-like material a predetermined diaphragm shape. The injection molding step includes injecting synthetic resin material constituting the first diaphragm layer into the injection molding die thus closed thereby to form the first diaphragm layer.

Method for manufacturing diaphragm for use in electroacoustic transducer

A substrate () made by a thin magnesium plate having a thickness of at most 60 &#x3bc;m and bent in a predetermined shape is subjected to anodic oxidation using an alkali-mixture aqueous solution containing metallic salt with a pH 12 or more so that porous anodic oxide coatings () are formed on the surfaces thereof. A first treated substrate () having the anodic oxide coatings () is immersed in a bath of a dye (B), which fills the pores (A) of the anodic oxide coatings () and dyes the substrate, providing a second treated substrate (). The second treated substrate () is subjected to electrodeposition using electrodeposition paint made mainly of acrylic resin, forming electrodeposition coatings () on the anodic oxide coatings (). A magnesium diaphragm is thereby produced, which is thin and has sufficient sensitivity and desired characteristics. The diaphragm thus dyed has metallic gloss and hence acquires a high decorative value.

Magnesium diaphragm, method of manufacturing the same, and speaker apparatus

In a rolling process, the level of rolling performed by a rolling mill for one operation is set to 1 &#x3bc;m to 20 &#x3bc;m. A magnesium substrate is rolled by rollers while being heated by a thermostatic chamber. As a result, there is manufactured a high-quality magnesium sheet which is less susceptible to influence of oxidation, which realizes a high internal loss, prevention of a drop in sensitivity, and low distortion, and which has a thickness of 30 &#x3bc;m to 100 &#x3bc;m. Further, as a result of the magnesium sheet being formed into a semi-dome shape or a dome shape, the sheet can be inexpensively manufactured as a speaker for high-tone playback. In particular, in the case of a magnesium diaphragm into which a dome section and an edge section are integrally formed, high-quality sound can be played back in a high frequency range without involvement of a drop in sensitivity.

Method of manufacturing a magnesium diaphragm

A molten resin is injected into a cavity together with long fibers. Opposite surfaces of the resin are solidified as a fiber-resin mixture temperature drops. These surface layers become non-foam layers. A foam layer is created between the non-foam layers. A pressure reduction process is applied to cause a spring back effect when the foam layer is created. A diaphragm having these three layers can be manufactured in an inexpensive process, but physical characteristics and appearances of the diaphragm are not sacrificed.

Diaphragm for electroacoustic transducer and method of making the same

A speaker's surround to be attached to an edge of a diaphragm in a speaker system is provided, which is capable of keeping its predetermined shape while repeating elastic deformation for accommodating large amplitude vibration of the diaphragm. Further, the surround is highly durable to withstand the repeated large amplitude vibration, and which can achieve high sound pressure levels. The surround for a speaker system includes a surround piece made of a rubber mold and a base member embedded in the surround piece. The base member is obtained by soaking a cloth material made of cotton or aramid fiber with a thermosetting resin such as phenol resin, and press-formed with heat into a predetermined shape. The surround thus has enhanced its shape maintaining capability.

Surround for speaker system and manufacturing method thereof

A frame of an electroacoustic transducer is made from a mixture of a thermoplastic resin and long fibers dispersed in the resin. The long fibers serve as reinforcing fibers. The long fibers have an average length sufficient to achieve a spring back effect. The spring back effect creases a foam structure. The electroacoustic transducer frame includes single-layer portions and three-layer portions. The single-layer portion is made of a non-foam layer. The three-layer portion is made of a pair of non-foam layers and a foam layer sandwiched by the non-foam layers. The electroacoustic transducer frame is lightweight, and has high internal loss, high rigidity and improved environmental resistance.

Electroacoustic transducer frame and method of making the same

A damper for a speaker includes an auxiliary damper impregnated with a thermosetting resin, a laminate film laminated on the auxiliary damper , and a primary damper formed on the auxiliary damper or the laminate film . Alternatively, the damper may include the auxiliary damper impregnated with the thermosetting resin (phenol) and coated with a coating agent, and the primary damper formed on the auxiliary damper and the coating agent . Thus, the dual damper which has enhanced reliability in resisting a high power and can be produced at a low cost without variation in the production can be obtained.

Damper for speaker and method of producing the same

A molded foam resin, surface of which can be designed easily at low cost, a process for forming a molded foam resin, and a speaker diaphragm made of molded foam resin are provided, in which a molded foam resin is formed by injection molding of foaming agent-containing resin and has a foamed zone having a three layer-structure consisting of a foamed layer inside and a non-foamed layer outside and a non-foamed zone having a single layer-structure consisting of a non-foamed layer. The process for forming the molded foam resin according to the present invention includes the steps of injecting a foaming agent-containing resin into a mold and opening the mold after a lapse of a designated period of time after the completion of the injection, in which a cavity of the mold contains a thick space corresponding to the foamed zone and a thin space corresponding to the non-foamed zone, and the designated period of time is chosen so that a curing of the resin filled into the thin space is completed and a curing of the resin filled into the thick space is not completed. Thus, a molded foam resin and a speaker diaphragm according to the present invention can be thinned, designed with different tone of color on surfaces thereof and lightened without deteriorating stiffness thereof.

Molded foam resin, process for forming the same and speaker diaphragm consisting of the same

A method of producing a loudspeaker vibrating diaphragm comprising the steps of injecting an amount of resin containing a foaming agent into a metallic mold of an injection molding machine, the mold including a fixed part and a movable part, reducing a mold pressing force of the injection molding machine upon completion of the resin injection, so as to enlarge a space formed between the fixed part and the movable part by a predetermined distance, so that the foaming agent is foamed to obtain a foam layer in the diaphgram.

Methods for making a loudspeaker vibrating diaphragm

A loudspeaker vibrating diaphragm with has a foam layer and two un-foamed skin layers formed on both sides of the foam layer. The average foaming magnification including the foam layer and two un-foamed skin layers is 1.1-3.0. The average foaming magnification is the ratio of the thickness of the resin after foaming (which equals the sum of the thicknesses of the foamed layer and the two un-foamed layers) to the thickness of the resin before foaming. The foam layer contains foaming bubble cells which are formed with their longer axes arranged in the thickness direction of the diaphragm. The thickness of each un-foamed skin layer is 0.05-0.20 mm.

Loudspeaker vibrating diaphragm and methods for its production

A butterfly damper for preventing an adhesion surface between a speaker frame (6) and an outer peripheral frame (12) from peeling off is provided. The butterfly damper comprises an inside peripheral flame (11), an outer peripheral flame (12) and a plurality of movable arms (13), all of which are formed in a single piece by injection molding of thermoplastic synthetic resin. The thickness T of the outer peripheral flame (12) is thicker than the thickness t of the movable arms (13). In addition, the front and back faces of the outer peripheral flame (12) are formed so that each face protrudes toward the thickness direction respectively from the front face and the back face of the movable arms (13).

Damper for speaker

A diaphragm used for a loudspeaker comprises polybutylene-terephthalate-polyester-elastomer. It has a flat audio spectrum property and excellent in internal loss, heat-resistance, light-resistance and water-resistance.

Diaphragm for electro-dynamic type loudspeakers

A lower die having a first recess corresponding to one of outer shapes of the element, and an upper die having a second recess are provided. The outer diameter of the upper dies is smaller than the inner diameter of the first recess so that a gap is formed between the inside wall of the first recess and the outside wall of the upper die. A workpiece is put between the lower and upper dies, and the upper die is pressed against the lower die to form the element.

Growing community of inventors

Yamagata, Japan

Masatoshi Sato