Abstract: A smaller-sized speaker cabinet developed in this invention is made of a mixture that is composed of a woody cellulose powder of proper physical properties and a synthetic resin blended with this powder. The resin is a non-chlorinated resin, and the cellulose powder consists of particles whose diameters are included in a range from about 5 ?m to 500 ?m. The cellulose powder is surface-treated to increase affinity for the resin, so that efficient manufacture of the cabinets of improved acoustic performance is now possible.

Abstract: A loudspeaker diaphragm manufacturing apparatus of the present invention comprises; a paper tank, a pulp dispersion reservoir tank connected to the paper tank, a stirring means provided in the paper tank, a water inlet unit connected to the paper tank, a drain unit disposed under the paper tank, and a paper mold disposed at the bottom of the paper tank or in the drain unit, wherein a sectional area of the drain unit is larger than the plane area of the paper mold. The drain unit may be further provided with a water flow control plate in a draining direction of the paper mold. According to the manufacturing apparatus and the manufacturing method of the present invention, diaphragms with very uniform internal composition and diaphragms with intentionally varied internal composition in accordance with required sound characteristics can be mass-produced with good reproducibility.

Abstract: A speaker is provided in which a coil wire can withstand a large amplitude motion caused by vibration of a voice coil bobbin and a diaphragm, and in which a bias of weight of the voice coil bobbin and the diaphragm caused by a constitution of the coil wire is reduced to a minimum. The coil wire, winding around the voice coil bobbin, is composed of a core thread having a bending strength and a heat-resistance and is wound by a conductive material. An end of the coil wire is directly connected to an external input terminal attached to a frame.

Abstract: A speaker diaphragm edge obtained by hot-forming into a desired edge shape, a resin-treated base material, which was prepared by using a silkscreen printing technique to apply a shaping agent layer only to the necessary portion of a base material.

Abstract: A piezoelectric loudspeaker includes: a diaphragm; a first piezoelectric material provided in a first area of the diaphragm; and a second piezoelectric material provided in a second area of the diaphragm different from the first area. The second area has a sound reproduction band different from that of the first area. This piezoelectric loudspeaker has a wide reproduction frequency range.

Abstract: The invention provides a speaker, in which a coil wire withstands a large amplitude motion caused by vibration of a voice coil bobbin and a diaphragm, and in which a bias of weight of the voice coil bobbin and the diaphragm caused by a constitution of the coil wire is reduced to a minimum, therewith a speaker is provided with reliability and a superior sound quality. The coil wire, winding around the voice coil bobbin (80), is composed of a core thread having a bending strength and a heat-resistance and is wound by a conductive material. An end of the coil wire is directly connected to an external input terminal (90) attached to a frame (50).

Abstract: A diaphragm is gained by the co-molded of a dome part, a voice coil junction part, a cone part and a peripheral part through the injection mold of thermoplastic resin. The thickness of the central part of the dome is made great so that the resonance amplitude in this part becomes small. In addition, an annular rib is integrally provided to the voice coil junction part so as to increase the junction strength between the diaphragm and the voice coil bobbin. Thus, the electromagnetic driving force of the voice coil can be effectively transmitted to the diaphragm so that a loud speaker with excellent characteristics can be gained.

Abstract: A loudspeaker diaphragm manufacturing apparatus of the present invention comprises; a paper tank, a pulp dispersion reservoir tank connected to the paper tank, a stirring means provided in the paper tank, a water inlet unit connected to the paper tank, a drain unit disposed under the paper tank, and a paper mold disposed at the bottom of the paper tank or in the drain unit, wherein a sectional area of the drain unit is larger than the plane area of the paper mold. The drain unit may be further provided with a water flow control plate in a draining direction of the paper mold. According to the manufacturing apparatus and the manufacturing method of the present invention, diaphragms with very uniform internal composition and diaphragms with intentionally varied internal composition in accordance with required sound characteristics can be mass-produced with good reproducibility.

Abstract: A speaker diaphragm edge obtained by hot-forming into a desired edge shape, a resin-treated base material, which was prepared by using a silkscreen printing technique to apply a shaping agent layer only to the necessary portion of a base material.

Abstract: A speaker edge is made of a thermosetting composition consisting of a polyurethane prepolymer and an inactivated solid polyamine as a latent hardener. A gas is dispersed in the thermosetting composition, prior to feed into a mold, so that it can foam and solidify to give the speaker edge. In a method of making the speaker edge, the composition will be injected into a female mold segment heated below the critical thermosetting temperature, foaming the composition. Then placed in the female segment is a male segment heated above the critical temperature, causing the ingredients to react with each other to solidify in the mold.

Abstract: A speaker edge is made of a thermosetting composition consisting of a polyurethane prepolymer and an inactivated solid polyamine as a latent hardener. A gas is dispersed in the thermosetting composition, prior to feed into a mold, so that it can foam and solidify to give the speaker edge. In a method of making the speaker edge, the composition will be injected into a female mold segment heated below the critical thermosetting temperature, foaming the composition. Then placed in the female segment is a male segment heated above the critical temperature, causing the ingredients to react with each other to solidify in the mold.

Abstract: A diaphragm is gained by the co-molded of a dome part, a voice coil junction part, a cone part and a peripheral part through the injection mold of thermoplastic resin. The thickness of the central part of the dome is made great so that the resonance amplitude in this part becomes small. In addition, an annular rib is integrally provided to the voice coil junction part so as to increase the junction strength between the diaphragm and the voice coil bobbin. Thus, the electromagnetic driving force of the voice coil can be effectively transmitted to the diaphragm so that a loud speaker with excellent characteristics can be gained.

Abstract: A damper for a loud speaker is produced by molding a substrate into a desired shape in which a fabric or knitted cloth composed of core-sheath type conjugate fibers composed of filaments having a core-sheath type structure is used as the substrate. A resin used for forming a core material in the core-sheath type structure functions as a matrix of the substrate. A sheath material having a lower melting point than that of the core material functions as an excipient, and is fused by a heat treatment and then solidified during the molding process, so as to bond together the intersections of fibers constituting the substrate and to cover the surface of the fibers. Thus, only a simple substrate production process is required and a damper for a loud speaker having excellent moldability, water-proofness, and durability is obtained.

Abstract: Water-proofed natural pulp or organic synthetic fibers are with polyester-type fibers having a low melting point, and subjected to a paper fabrication process. The fabricated product is dried with hot air at a temperature higher than the melting point of the polyester-type fibers, thereby melt-bonding only intersections of the fibers without completely fusing the polyester-type fibers. The pressure of the hot air contributes to the formation of a predetermined shape. Thus, a water-proof diaphragm for a loudspeaker, having a large thickness, a low density, a high internal loss and a high stiffness, is obtained. By incorporating the thus formed diaphragm, a high-performance loudspeaker having a low distortion and a broad reproducing range is obtained.

Abstract: A damper for a loud speaker is produced by molding a substrate into a desired shape in which a fabric or knitted cloth composed of core-sheath type conjugate fibers composed of filaments having a core-sheath type structure is used as the substrate. A resin used for forming a core material in the core-sheath type structure functions as a matrix of the substrate. A sheath material having a lower melting point than that of the core material functions as an excipient, and is fused by a heat treatment and then solidified during the molding process, so as to bond together the intersections of fibers constituting the substrate and to cover the surface of the fibers. Thus, only a simple substrate production process is required and a damper for a loud speaker having excellent moldability, water-proofness, and durability is obtained.

Abstract: Water-proofed natural pulp or organic synthetic fibers are with polyester-type fibers having a low melting point, and subjected to a paper fabrication process. The fabricated product is dried with hot air at a temperature higher than the melting point of the polyester-type fibers, thereby melt-bonding only intersections of the fibers without completely fusing the polyester-type fibers. The pressure of the hot air contributes to the formation of a predetermined shape. Thus, a water-proof diaphragm for a loudspeaker, having a large thickness, a low density, a high internal loss and a high stiffness, is obtained. By incorporating the thus formed diaphragm, a high-performance loudspeaker having a low distortion and a broad reproducing range is obtained.

Abstract: There is provided a speaker damper for use in an acoustic output device, which exhibits excellent shape retaining property at the time of molding, is highly safe to work environment and has excellent water resistance, heat resistance an durability. The speaker damper is obtained by impregnating cloth formed of mixed yarn of a wholly aromatic polyamide fiber and an aromatic polyester fiber with a polyester resin, and molding the cloth under heat and pressure.

Abstract: The loudspeaker of the invention includes: a frame; a diaphragm, a planar shape thereof being non-axisymmetric having a larger diameter and a smaller diameter when the diaphragm is viewed from a vibration direction thereof; a band-shaped edge portion provided around an outer periphery of the diaphragm, an outer periphery of the edge portion being connected to the frame and an inner periphery of the edge portion being connected to the diaphragm; a cylindrical voice coil bobbin in a non-axisymmetric shape having a larger diameter and a smaller diameter which includes a pair of opposed faces parallel to each other in a larger diameter direction, one end portion of the voice coil bobbin being connected to the diaphragm; a voice coil wound around the voice coil bobbin; a plurality of voice coil bobbin reinforcing members in a plate shape which are bridged between the pair of opposed faces parallel to each other of the voice coil bobbin; and a plurality of magnetic circuits having a gap for applying magnetic fluxes

Abstract: A diaphragm for an electroacoustic transducer comprising stratiform mineral of layers into which a hardener or an agent for facilitating hardening is adsorbed between the layers, thermosetting resin monomer, and carbonfibers which constitute a composite material which is formed under heat and pressure. The diaphragm is increased in rigidity which is required as physical properties therefor and is easy in forming.