Abstract: A speaker diaphragm of the present invention is formed by mixing polylactic acid as a plant-derived resin, bamboo fibers and a natural binder. It is thereby possible to realize a speaker diaphragm capable of obtaining sufficient sound velocity, while having low environmental load and high sound quality.

Abstract: A loudspeaker includes a diaphragm, a voice coil fixed to the diaphragm, a first magnet having a first pole surface facing an inner side of the voice coil, a second magnet located inside the inner side of the voice coil, and a first magnetic fluid provided between the first pole surface of the first magnet and the voice coil. The first magnet has the first pole surface facing the inner side of the voice coil. The second magnet has a second pole surface located inside the inner side of the voice coil such that a magnetic flux passing through the first pole surface of the first magnet crosses the voice coil in a direction perpendicular to the voice coil and a vibration direction. The first magnetic fluid contacts the first pole surface and the voice coil. The loudspeaker has a small thickness but can produce a high audio output, while preventing rolling.

Abstract: A voice coil wound to have a loop having an inner side is fixed to a diaphragm vibrating in a vibration direction. A first magnet having a first pole surface is fixed to an upper case. A second magnet having a second pole surface is fixed to a lower case. A first magnetic fluid is attached to the first pole surface of the first magnet after fixing the first magnet to the upper case. The diaphragm is fixed to the upper case after fixing the voice coil to the diaphragm and after attaching the first magnetic fluid to the first pole surface of the first magnet, such that the first pole surface of the first magnet faces the inner side of the voice coil and that the first magnetic fluid is provided between the first pole surface of the first magnet and the voice coil and contacts the first pole surface and the voice coil.

Abstract: According to the present invention, there is provided a speaker for use in audio/video apparatuses and a small-sized speaker device capable of realizing preferable reproduction a bass sounds. In order to attain this, in the present invention, a pressure adjusting body is coupled to a portion of a magnetic circuit or a frame, which is a component of a speaker unit, to constitute the speaker unit. The speaker unit is mounted to a small-sized cabinet to constitute a speaker device, which enables realization of preferable reproduction of bass sounds.

Abstract: In a loudspeaker, three magnets are disposed with magnetic gaps formed between them for placing therein a voice coil. The magnets disposed at two sides are so magnetized that the confronting poles have the same polarity. The magnet in the center has its magnetic poles in a direction perpendicular to a direction connecting the poles of the magnets at two sides. A diaphragm has an aperture formed in a position confronting the center magnet. Also provided is a magnetic fluid kept mediating between the sides of the center magnet facing the magnetic gaps and the voice coil.

Abstract: A speaker diaphragm is configured by a compound mixed with resin and bamboo fiber. The diaphragm satisfying the advantage of the bamboo fiber of high sound quality and a large degree of freedom in the setting of the characteristic value of the diaphragm and the advantage of the diaphragm made of a resin with improved humidity resistance reliability and strength, excellent external appearance, and enhanced productivity and dimension stability is obtained.

Abstract: A manufacturing method of a paper making part for a loudspeaker has freedom of adjusting a characteristic and a sound quality, and has a higher productivity. Accordingly, a fibrillating step of a paper making material is achieved by an explosive crushing step. Alternatively, the step is achieved by a mixing step of a paper making material and a liquid, a material micro-fabricating step of applying a pressure to a mixed solution obtained by the mixing step so as to pass through an orifice and thereafter run into a device wall, and a paper making step including the micro-fabricated material.

Abstract: In a process for producing a loudspeaker diaphragm, pulp is deposited on a paper-making mold in the presence of vortex stream of water having pulp dispersed therein in a paper-making bath. Pulp is deposited on the paper-making mold while at least the water having pulp dispersed therein is rotated by the vortex stream in the paper-making bath. Consequently, variation of pulp fiber orientation is suppressed, and a loudspeaker diaphragm with high reproducibility and stable quality is produced with a high productivity.

Abstract: Provided is a loudspeaker using a resin with adhesiveness as a surface treatment agent that has already been applied onto either of a diaphragm and a voice coil before bonding. Because this structure can reduce the weight of an adhesive agent used for bonding the diaphragm to the voice coil, a sound pressure level can be improved.

Abstract: A loudspeaker of high sound quality is achieved by improving rigidity of a material used for a diaphragm, a dust cap and a sub-cone. The diaphragm, the dust cap and the sub-cone of the loudspeaker are made of a paper beaten with the material containing bamboo fibers obtained from a bamboo tree aged one year or older, of which the fibers are finely beaten to an extent of micro-fibrillated form. The diaphragm and the dust cap are also made with a beaten paper containing at least 2 wt % of “A fibers” having stems of no greater than 30 ?m in diameter, and surfaces of the stems are fibrillated into shaggy branches having diameters of 1 ?m or less.

Abstract: The production equipment of paper-made components for loudspeakers includes a mixing device, a fining device, a paper-making device, and a shape processing device. The mixing device mixes material of a paper-made component for a loudspeaker into liquid to generate mixed liquid. The fining device includes a pressure unit, an orifice, and an inner wall. The pressure unit applies pressure on the mixed liquid to cause the mixed liquid to pass through the orifice, and the mixed liquid collides against the inner wall to cause the fining device to generate fined material. The paper-making device paper-makes the fined material to generate a paper-made component. The shape processing device processes the shape of the paper-made component. This structure provides production equipment of the paper-made components for loudspeakers, which prepares material for paper-making in a short time and reduces producing time.

Abstract: A loudspeaker damper, a manufacturing method thereof, and a loudspeaker, electronic equipment and device using the loudspeaker damper. The damper has flexibility. Therefore, even if a large input is applied and the damper oscillates with a large amplitude, a resin layer provided on the surface of the damper base material is not cracked due to partial interface peeling. Thus, the damper follows such a large amplitude and realizes high input-resistance. This loudspeaker damper material is obtained by impregnating a material with thermosetting resin including 2 to 20 wt % of flexibility imparting agent and heat-curing thereof.

Abstract: A diaphragm for a loudspeaker contains resin, aramid fibers, and an organic silicon compound binding the resin with the aramid fibers. By this structure, high elasticity and high internal loss as characteristics of the aramid fibers are maintained; flexibility in the setting of properties of the diaphragm is thus increased. Accordingly, a diaphragm securing humidity resistance reliability and strength, and having a superior appearance can be provided.

Abstract: In a process for producing a loudspeaker diaphragm, pulp is deposited on a paper-making mold in the presence of vortex stream of water having pulp dispersed therein in a paper-making bath. Pulp is deposited on the paper-making mold while at least the water having pulp dispersed therein is rotated by the vortex stream in the paper-making bath. Consequently, variation of pulp fiber orientation is suppressed, and a loudspeaker diaphragm with high reproducibility and stable quality is produced with a high productivity.

Abstract: A smaller-sized and acoustically excellent speaker diaphragm is inexpensively provided using the mixture of a specially surface-coated woody material and a mass-producible synthetic resin. The mixture is composed of a non-chlorinated synthetic resin and a powdery cellulose material whose particle size falls within a range of from 5 ?m to 500 ?m. The cellulose material has been subjected to a surface treatment to enhance its affinity to the non-chlorinated synthetic resin, and 30% to 70% by weight of the cellulose material is contained in the mixture.

Abstract: A diaphragm for an electro-acoustic converter is made of an aromatic polyimide film. A glass transition temperature of the film is 230° C.-300° C. The aromatic polyimide film is made from a carboxylic acid component containing dicarboxylic acid compound having two or more number of ether-linked benzene rings as the major component and a diamine component containing diaminophenyl ether as the major component.

Abstract: A screen printing ink includes micelle structural particles formed by aggregating molecules of ammonium acrylate to dispersed particles containing phenol resin, and a dispersion medium for dispersing the micelle structural particle.

Abstract: A speaker diaphragm or a dust cap formed by injection molding a mixture at least containing a resin material and a fiber material. The speaker diaphragm or the dust cap combines the advantages of both a paper diaphragm and a resin diaphragm. The advantage of a paper diaphragm is a large degree of freedom in setting physical properties. The advantages of a resin diaphragm are being excellent in moisture resistance reliability, strength, external appearance, productivity and dimension stability.

Abstract: [OBJECTS] To provide an elastic strip material that has a cross-sectional shape suited to intended uses such as seals or cushions, as well as a method of and an apparatus for mass-producing the strip material efficiently and inexpensively. [MEANS FOR ACHIEVING THE OBJECTS] A heat setting composition is used whose main ingredients are a polyurethane prepolymer and a latent solidifier obtained by deactivating a solid polyamine. A compressed gas is dispersed throughout the composition to give a fluid mixture ‘a’, that is then foamed and heated to or above a critical temperature to solidify as the strip material. The fluid mixture ‘a’ is extruded from an extruder (1), guided into a liquid or gaseous heating zone (2), caused to solidify during travel within the zone, and shaped at the same time into a desired configuration before discharged from the zone (2).

Abstract: The present invention is directed to a speaker using lightweight, highly rigid diaphragm having excellent frequency characteristic and improving resistance to environment (including resistance to UV and resistance to fading). For this end, the speaker utilizes a cone-shaped diaphragm made from foamed or cellular resin such as polyethylene terephthalate (PET) resin or polyethylene naphthalate (PEN) resin with 30 ?m average cell size. The use of such cone-shaped diaphragm is effective to improve sound quality of the speaker.