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 process for producing an aluminum electrode foil for a capacitor, which includes a first step of preparing an emulsion from a mixture including a first phase of a liquid resin or a resin solution obtained by dissolving a resin in a solvent, a second phase of a liquid that is incompatible with the first phase, and an emulsifier; a second step of coating the emulsion on a surface of an aluminum foil; a third step of removing the second phase to form a resin film having a plurality of pores on its surface; a fourth step of etching the aluminum foil having the resin film formed thereon; and a fifth step of removing the resin film after etching. The production process can form high-density etching pits with high accuracy.

Abstract: Disclosed is a speaker comprising a frame connected with a magnetic circuit having a magnetic gap, a voice coil disposed adjacent to but not in contact with an upper side of the magnetic circuit, and a diaphragm bonded to a circumferential edge of the frame, wherein the frame and the diaphragm are configured into such peripheral shapes that conform to a mounting space allowed for the speaker inside an apparatus. This structure allows an external shape of the speaker to be freely configurable according to a limited space, yet the irregularly-shaped diaphragm is capable of being driven with an uniform amplitude, thereby providing an advantage of down-sizing and high performance.