Abstract: A damper for a speaker for vibratably supporting a voice coil to a static part includes a first damper and a second damper formed in an annular shape having an inner periphery part and an outer periphery part, respectively. The first and second dampers are formed in a shape expandable and contractable in a direction crossing a circumferential direction of the annular shape. The inner periphery part of the second damper is connected to the first damper between the inner periphery part and the outer periphery part of the first damper, and each outer periphery part of the first damper and the second damper is connected to each other such that annular space is formed between the first damper and the second damper.

Abstract: A substrate (580) made by a thin magnesium plate having a thickness of at most 60 ?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 (571) are formed on the surfaces thereof. A first treated substrate (581) having the anodic oxide coatings (571) is immersed in a bath of a dye (571B), which fills the pores (571A) of the anodic oxide coatings (571) and dyes the substrate, providing a second treated substrate (582). The second treated substrate (582) is subjected to electrodeposition using electrodeposition paint made mainly of acrylic resin, forming electrodeposition coatings (572) on the anodic oxide coatings (571). 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.

Abstract: In a rolling process, the level of rolling performed by a rolling mill for one operation is set to 1 ?m to 20 ?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 ?m to 100 ?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.

Abstract: A ribbon-shaped speaker device includes a magnetic circuit which has two magnetic gaps; two diaphragms which have conductive properties and which are arranged substantially in parallel with and opposite to each other in each of the magnetic gaps; and a driving part which supplies a driving current to each of the diaphragms. A direction of a magnetic flux in each of the magnetic gaps and a direction of the driving current supplied to each of the diaphragms are set such that each of the diaphragms moves in a same direction. Each of the diaphragms inclines in a direction adjacent to each other.

Abstract: A butterfly damper for supporting a voice coil bobbin of a speaker on a frame in a state that the damper is vibrative. The butterfly damper is made of olefinic resin material having an internal loss of 0.045 or greater, a tensile elongation of 200% or greater, and a flexural modulus of 300 MPa or greater.

Abstract: A speaker diaphragm and a method of fabricating the same with the reduced number of fabrication steps and high production efficiency, from which a stable rust-proof effect can be expected without generating any variation in rust resistance, are provided. After a diaphragm base material formation step, a diaphragm base material is molded at a molding step. Thereafter, a first trimming step for forming trim holes along an outer circumference is conducted. A molded diaphragm product is supported to a diaphragm base material through supporting sections. Then, at a surface treatment step, after an anodic oxidation coating is formed on a surface of the molded diaphragm product at an anodization substep, electrodeposition coating is formed at an electrodeposition coating substep. Subsequently, a second trimming step of cutting the supporting sections is conducted to form a magnesium diaphragm including convex portions on the outer circumference.

Abstract: It is an object of the present invention to provide a speaker device equipped with a damper having an improved durability. Namely, the speaker device is equipped with a damper containing aramid fiber. An adhesive material is interposed between the damper and a frame. A perimeter edge portion of the damper is clamped between the frame and a ring-shaped member arranged along the perimeter edge portion, with screws driven down trough related material layers, thereby fixing the damper on the frame.

Abstract: In the rolling process, a rolling amount at each time of rolling by a rolling machine is set to 1 ?m to 20 ?m, and a magnesium substrate is heated by a constant temperature oven and rolled by rollers. Thus, a magnesium sheet of 30 ?m to 100 ?m is produced. This magnesium sheet is used to form a bobbin and a diaphragm integrally molded with each other, and the diaphragm is molded into a semi-dome shape or a dome shape. Thus, a bobbin integrated type magnesium diaphragm having the semi-dome shaped diaphragm or the dome shaped diagram is manufactured. The bobbin integrated type magnesium diaphragm is applied to a dynamic speaker device. As a result, the high-quality dynamic speaker device, which realizes high rigidity, high sensibility, high internal loss, less distortion and the like, is obtained.

Abstract: A vibrating plate for a speaker, includes: a magnesium vibrating plate whose major component is magnesium; and an edge comprising a resin in which an inner peripheral edge of the edge is bonded to an outer peripheral edge of the magnesium vibrating plate for attaching the magnesium vibrating plate to a frame, in which the inner peripheral edge of the edge is constituted by a structure having a pinching groove which the outer peripheral edge of the magnesium vibrating plate is brought into close contact with and fitted to, and the edge is formed integrally with the magnesium vibrating plate by insert molding.

Abstract: A substrate (580) made by a thin magnesium plate having a thickness of at most 60 ?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 (571) are formed on the surfaces thereof. A first treated substrate (581) having the anodic oxide coatings (571) is immersed in a bath of a dye (571B), which fills the pores (571A) of the anodic oxide coatings (571) and dyes the substrate, providing a second treated substrate (582). The second treated substrate (582) is subjected to electrodeposition using electrodeposition paint made mainly of acrylic resin, forming electrodeposition coatings (572) on the anodic oxide coatings (571). 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.

Abstract: In a rolling process, the level of rolling performed by a rolling mill for one operation is set to 1 &mgr;m to 20 &mgr;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 &mgr;m to 100 &mgr;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.

Abstract: There is provided an electrically conductive damper device for a speaker in which local bending is reduced and break-downs of material of the damper and metallic wires incorporated in the damper are prevented, by additionally providing one or more sheets of damper fabric as a reinforcing damper 142 and by bonding it to a main damper 141 by way of various kinds of resin, in order to reinforce a neck portion of the electrically conductive damper. Further, properties of the damper can be adjusted by varying an outer diameter of the reinforcing damper 142, or by selecting the resin to be employed as an adhesive.

Abstract: A damper for a speaker includes an auxiliary damper 12 impregnated with a thermosetting resin, a laminate film 121 laminated on the auxiliary damper 12, and a primary damper formed on the auxiliary damper 12 or the laminate film 121. Alternatively, the damper may include the auxiliary damper 12 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 122. 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.

Abstract: A butterfly damper for supporting a voice coil bobbin of a speaker on a frame in a state that the damper is vibrative. The butterfly damper is made of olefinic resin material having an internal loss of 0.045 or greater, a tensile elongation of 200% or greater, and a flexural modulus of 300 MPa or greater.

Abstract: There is provided an electrically conductive damper device for a speaker in which local bending is reduced and break-downs of material of the damper and metallic wires incorporated in the damper are prevented, by additionally providing one or more sheets of damper fabric as a reinforcing damper 142 and by bonding it to a main damper 141 by way of various kinds of resin, in order to reinforce a neck portion of the electrically conductive damper. Further, properties of the damper can be adjusted by varying an outer diameter of the reinforcing damper 142, or by selecting the resin to be employed as an adhesive.

Abstract: A damper for a speaker includes an auxiliary damper 12 impregnated with a thermosetting resin, a laminate film 121 laminated on the auxiliary damper 12, and a primary damper formed on the auxiliary damper 12 or the laminate film 121. Alternatively, the damper may include the auxiliary damper 12 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 122. 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.