Abstract: A speaker device includes: a magnetic circuit which includes two magnetic gaps; a diaphragm which is arranged at a position passing through at least the two magnetic gaps and includes a recessed part extending in a direction substantially orthogonal with respect to an extending direction of a magnetic flux in the magnetic gaps; and a voice coil, formed into an annular shape, which includes a first parallel part extending in one direction and a second parallel part extending in a direction in parallel with the first parallel part and opposite to the first parallel part with a constant space. Particularly, the first parallel part and the second parallel part are arranged in a direction in parallel with an extending direction of the recessed part, respectively, and the first parallel part and the second parallel part are arranged in the recessed part to be positioned in the two magnetic gaps, respectively.

Abstract: A diaphragm of a speaker device, formed into an elongated configuration, has a recessed shape and includes a voice coil arrangement part extending in its longitude direction. The voice coil arrangement part has a gap with a constant width in its lateral direction and includes a voice coil supporting part for supporting a voice coil and an expanded part provided at a position along it.

Abstract: A speaker device includes a magnetic circuit which includes a magnetic gap, a diaphragm which has a recessed part arranged in the magnetic gap and extending in a direction substantially orthogonal with respect to an extending direction of a magnetic flux in the magnetic gap, and a voice coil which is formed into an annular shape and has a first parallel part extending in one direction and a second parallel part extending in a direction in parallel with the first parallel part and opposite to the first parallel part with a constant space. Particularly, the first parallel part and the second parallel part are arranged in a direction in parallel with an extending direction of the recessed part, respectively. The first parallel part is arranged in the recessed part to be positioned in the magnetic gap, and the second parallel part is positioned above the recessed part.

Abstract: A lead wire of a voice coil is wired along the surface of a diaphragm. The lead wire is bent toward a reverse side of the diaphragm at a peripheral edge portion of the diaphragm. The lead wire is led to the interior of a frame. An external terminal is provided to extend from outside to inside the frame. In addition, a connecting portion for connecting the lead wire and the external terminal is provided inside the frame. The connecting portion is prevented from coming into contact with another part and becoming short-circuited.

Abstract: A magnetic circuit for a speaker device includes: a yoke which has magnetism and has a center pole formed into a column shape; and plural flat plate-shaped magnets which are uniformly arranged around the center pole and form a magnetic gap with the center pole. Each of the magnets is magnetized in a direction in parallel with a thickness direction and in a direction of the center pole. The magnetic circuit for the speaker device is a radial-type magnetic circuit. Since each of the flat plate-shaped magnets is formed not into a circular arc shape but into a flat plate shape, it becomes easy to form the magnets, and the number of procedures of forming of the magnets can be reduced. Additionally, since each of the flat plate-shaped magnets is magnetized in the thickness direction, a special magnetization machine becomes unnecessary. Thus, the number of procedures of magnetizing of the flat plate-shaped magnets can be reduced. As a result, the manufacturing cost of the magnetic circuit can be reduced.

Abstract: A speaker device includes: a magnetic circuit which includes two magnetic gaps; a diaphragm which is arranged at a position passing through at least the two magnetic gaps and includes a recessed part extending in a direction substantially orthogonal with respect to an extending direction of a magnetic flux in the magnetic gaps; and a voice coil, formed into an annular shape, which includes a first parallel part extending in one direction and a second parallel part extending in a direction in parallel with the first parallel part and opposite to the first parallel part with a constant space. Particularly, the first parallel part and the second parallel part are arranged in a direction in parallel with an extending direction of the recessed part, respectively, and the first parallel part and the second parallel part are arranged in the recessed part to be positioned in the two magnetic gaps, respectively.

Abstract: A diaphragm of a speaker device, formed into an elongated configuration, has a recessed shape and includes a voice coil arrangement part extending in its longitude direction. The voice coil arrangement part has a gap with a constant width in its lateral direction and includes a voice coil supporting part for supporting a voice coil and an expanded part provided at a position along it.

Abstract: A speaker device includes a magnetic circuit which includes a magnetic gap, a diaphragm which has a recessed part arranged in the magnetic gap and extending in a direction substantially orthogonal with respect to an extending direction of a magnetic flux in the magnetic gap, and a voice coil which is formed into an annular shape and has a first parallel part extending in one direction and a second parallel part extending in a direction in parallel with the first parallel part and opposite to the first parallel part with a constant space. Particularly, the first parallel part and the second parallel part are arranged in a direction in parallel with an extending direction of the recessed part, respectively. The first parallel part is arranged in the recessed part to be positioned in the magnetic gap, and the second parallel part is positioned above the recessed part.

Abstract: There is provided a speaker unit comprising: an elliptical vibrating diaphragm; a cylindrical voice coil secured at one end thereof on the center of the elliptical vibrating diaphragm; a frame structure for movably supporting the vibrating diaphragm, said frame structure being formed into a rectangular or elliptical shape and having a through hole in the center thereof; a magnetic circuit formed by (1) a top plate having a rectangular shape and having a through hole in the center thereof, (2) a plate-shaped magnet having a rectangular shape and having a through hole in the center thereof, (3) a back plate having a rectangular shape and having an upright pole on the center thereof. In this speaker unit, the top plate, the plate-shaped magnet and the back plate each has a width which is narrower than that of the frame structure in its shorter axis.

Abstract: A speaker apparatus includes an elliptical-shaped or a round-edged rectangular-shaped vibration plate; an edge damper portion disposed on an outer peripheral edge portion of the vibration plate; a recessed portion formed between said vibration plate and said edge damper portion, having a caliber of a shape corresponding to the shape of said vibration plate; and an air core voice coil fitted into an interior of said recessed portion. The speaker apparatus further includes a frame for mounting said edge damper portion to support said vibration plate, having a stepped portion and a vertical wall portion; and an edge damper frame arranged on an outer periphery of said edge damper portion, having a support portion placed on the stepped portion and a rising portion being in contact with the vertical wall portion.

Abstract: A lead wire of a voice coil is wired along the surface of a diaphragm. The lead wire is bent toward a reverse side of the diaphragm at a peripheral edge portion of the diaphragm. The lead wire is led to the interior of a frame. An external terminal is provided to extend from outside to inside the frame. In addition, a connecting portion for connecting the lead wire and the external terminal is provided inside the frame. The connecting portion is prevented from coming into contact with another part and becoming short-circuited.

Abstract: There is provided a speaker or a speaker system which has no chance of disabled ventilating air in a space enclosed with a voice coil bobbin to outside of the magnetic circuit through a throughhole C formed in a magnetic circuit to communicate with the space enclosed with a voice coil bobbin, even if mounting a speaker between inner surfaces of a casing, because of enabled ventilating air from a space enclosed with a voice coil bobbin to outside of a magnetic circuit through an air path 3c formed in the magnetic circuit to communicate with the throughhole C.

Abstract: A speaker apparatus includes an elliptical-shaped or a round-edged rectangular-shaped vibration plate; an edge damper portion disposed on an outer peripheral edge portion of the vibration plate; a recessed portion formed between said vibration plate and said edge damper portion, having a caliber of a shape corresponding to the shape of said vibration plate; and an air core voice coil fitted into an interior of said recessed portion. The speaker apparatus further includes a frame for mounting said edge damper portion to support said vibration plate, having a stepped portion and a vertical wall portion; and an edge damper frame arranged on an outer periphery of said edge damper portion, having a support portion placed on the stepped portion and a rising portion being in contact with the vertical wall portion.

Abstract: There is provided a speaker or a speaker system which has no chance of disabled ventilating air in a space enclosed with a voice coil bobbin to outside of the magnetic circuit through a throughhole C formed in a magnetic circuit to communicate with the space enclosed with a voice coil bobbin, even if mounting a speaker between inner surfaces of a casing, because of enabled ventilating air from a space enclosed with a voice coil bobbin to outside of a magnetic circuit through an air path 3c formed in the magnetic circuit to communicate with the throughhole C.

Abstract: A dome speaker comprises a dome section including a vibrating diaphragm having a dome shape, an annular edge damper section provided surrounding the dome section, an annular coil holder provided between the dome section and the annular edge damper section for holding a voice coil. In particular, the dome section further includes a cap having substantially the same shape as the vibrating diaphragm, said cap being bonded on the said vibrating diaphragm.

Abstract: 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.

Abstract: A speaker unit has a cylindrical yoke, an annular frame secured to the yoke, and a diaphragm having a central spherical vibrating portion and an annular support portion formed around the vibrating portion and mounted on the annular frame. An annular vertical holding wall is formed on the annular frame, and an annular vertical abutment portion is formed on the annular support portion and abutted against the annular vertical holding wall.

Abstract: 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.

Abstract: A magnetic circuit has a yoke base, a pole formed on the yoke base, an annular magnet mounted on the yoke base, an annular plate having an inclined surface mounted on the magnet. The annular plate has an inwardly downwardly curved sectional shape toward a periphery. A frame for a conical diaphragm is secured to the plate. A plurality of platforms each having a flat surface are formed on the inclined surface, and a plurality of staking projections are formed on the flat surfaces of the platforms. The frame is secured to the plate by staking the staking projections.

Abstract: 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.