Abstract: A speaker apparatus which can remove undesirable vibrations and can produce sounds of excellent quality of acoustic signals having high audio frequencies is presented by increasing a strength of a flat joint portion and by properly setting a mass ratio between a central dome-like diaphragm and an edge-like diaphragm of a speaker diaphragm. This speaker apparatus includes a diaphragm portion in which a mass ratio of the edge-like diaphragm relative to the dome-like diaphragm falls within a predetermined range near 1 and a fixed portion at which a bobbin of a voice coil or an end face of a conductive one turn ring is bonded to and fixed to a flat portion for joining the dome-like diaphragm and the edge-like diaphragm so that mechanical strength of a joint flat portion of the diaphragms can be increased.

Abstract: A speaker device includes a speaker diaphragm composed of a selected acoustic diaphragm material whose acoustic loss coefficient (tan &dgr;) is more than 0.02 in a frequency band over 20 kHz, and including a dome positioned at the center of the diaphragm and shaped to be substantially arcuate in its cross section, with an edge positioned outside the dome and formed integrally therewith through a link; and a conductive one-turn ring inserted into a magnetic gap and bonded fixedly, at one end thereof, to the link between the dome and the edge of the speaker diaphragm. In this device, signals of a frequency band over 20 kHz are reproduced by utilizing the split vibrations of the speaker diaphragm.

Abstract: A loudspeaker in which the input resistance is improved and the effect of humidity on the playback frequency response is suppressed, and a method for the preparation of the loudspeaker. A sheet-like product, containing glass particles with a particle size of 8 nm to 300 nm and polyamide resin, and prepared by application of a paper-making technique, is used as the diaphragm. The content of the glass particles in the compound material is 5 weight % to 70 weight %. In preparing the diaphragm, a phase of an aqueous solution containing diamine and water glass is contacted with a phase of an organic solution containing a dicarboxylic acid halide to generate a compound material containing glass particles and the polyamide resin. The compound material so prepared is formed into a sheet by a paper-making technique. In the process of the preparation by the paper-making technique, the compound material mixed with other fibrous material may also be used as a starting material.

Abstract: A speaker device includes a speaker diaphragm composed of a selected acoustic diaphragm material whose acoustic loss coefficient (tan &dgr;) is more than 0.02 in a frequency band over 20 kHz, and including a dome positioned at the center and shaped to be substantially arcuate in its cross section, and an edge positioned outside the dome and formed integrally therewith through a link; and a conductive one-turn ring inserted into a magnetic gap and bonded fixedly, at one end thereof, to the link between the dome and the edge of the speaker diaphragm. In this device, signals of a frequency band over 20 kHz are reproduced by utilizing the split vibrations of the speaker diaphragm.

Abstract: A loudspeaker in which the input resistance is improved and the effect of humidity on the playback frequency response is suppressed, and a method for the preparation of the loudspeaker. A sheet-like product, containing glass particles with a particle size of 8 nm to 300 nm and polyamide resin, and prepared by application of a paper-making technique, is used as the diaphragm. The content of the glass particles in the compound material is 5 weight % to 70 weight %. In preparing the diaphragm, a phase of an aqueous solution containing diamine and water glass is contacted with a phase of an organic solution containing a dicarboxylic acid halide to generate a compound material containing glass particles and the polyamide resin. The compound material so prepared is formed into a sheet by a paper-making technique. In the process of the preparation by the paper-making technique, the compound material mixed with other fibrous material may also be used as a starting material.

Abstract: A polymeric composite material contains a biodegradable polymeric material that can be biologically decomposed in soil. More specifically, it contains bacterial cellulose including ribbon-shaped micro-fibrils that can be biologically decomposed by microbes in addition to the biodegradable polymeric material and shows improved physical properties including tensile strength. Such a polymeric composite material can be prepared by a method including causing predetermined microbes cultured in a liquid culture medium to produce bacterial cellulose, collecting and drying the produced bacterial cellulose into a powdery state and mixing the powdery bacterial cellulose and a biodegradable polymeric material to produce a composite material.

Abstract: A method for manufacturing an acoustic vibration plate includes molding titanium metal into a shape of an acoustic vibration plate in order to obtain a titanium vibration plate, and performing a heat treatment on the titanium vibration plate by a ceramic-formation step, thereby to change entirely the titanium vibration plate into titanium oxide.

Abstract: A speaker apparatus which can remove undesirable vibrations and can produce sounds of excellent quality of acoustic signals having high audio frequencies is presented by increasing a strength of a flat joint portion and by properly setting a mass ratio between a central dome-like diaphragm and an edge-like diaphragm of a speaker diaphragm. This speaker apparatus includes a diaphragm portion in which a mass ratio of the edge-like diaphragm relative to the dome-like diaphragm falls within a predetermined range near 1 and a fixed portion at which a bobbin of a voice coil or an end face of a conductive one turn ring is bonded to and fixed to a flat portion for joining the dome-like diaphragm and the edge-like diaphragm so that mechanical strength of a joint flat portion of the diaphragms can be increased.

Abstract: A polymeric composite material contains a biodegradable polymeric material and hence can be biologically decomposed in soil. More specifically, it contains bacterial cellulose comprising ribbon-shaped micro-fibrils that can be biologically decomposed by microbes in addition to the biodegradable polymeric material and shows improved physical properties including tensile strength.

Abstract: A polymeric composite material contains a biodegradable polymeric material that can be biologically decomposed in soil. More specifically, it contains bacterial cellulose including ribbon-shaped micro-fibrils that can be biologically decomposed by microbes in addition to the biodegradable polymeric material and shows improved physical properties including tensile strength. Such a polymeric composite material can be prepared by a method including steps of causing predetermined microbes cultured in a liquid culture medium to produce bacterial cellulose, collecting and drying the produced bacterial cellulose into a powdery state and mixing the powdery bacterial cellulose and a biodegradable polymeric material to produce a composite material.

Abstract: An acoustic diaphragm production method including a step of filling a molten synthetic resin material through a sprue bush into a cavity defined by an injection molding metal mold according to a configuration of an acoustic diaphragm, a step of cooling the sprue bush with a cooling medium such as water, so as to solidify the resin in the sprue bush, a step of taking out a product from the metal mold, and a step of cutting off from the product a portion including a cold gate by way of press processing.

Abstract: This invention provides an acoustic vibrational material containing various fibers as the reinforcement material and having the epoxy resin as the matrix resin, wherein the epoxy resin is modified by a polybutadiene base elastomer containing not less than 90 mole percent of 1,2-linked units. The epoxy resin modified with the above polybutadiene elastomer exhibits a maximum value of loss coefficient at the temperature region near the room temperature. Thus compatibility between large internal loss and high elastic modulus is achieved.

Abstract: The present invention provides an optical disc recycling method for recycling optical disc including at least a light transmitting substrate and at least one metal layer containing a metal such as aluminium and gold provided on one side of the substrate. An adhesive member is adhered to the substrate side having the metal containing layer and the adhesive member adhered to the metal containing layer on the substrate is peeled off so as to separate the metal containing layer from the substrate.

Abstract: This invention provides an acoustic vibrational material containing various fibers as the reinforcement material and having the epoxy resin as the matrix resin, wherein the epoxy resin is modified by a polybutadiene base elastomer containing not less than 90 mole percent of 1,2-linked units. The epoxy resin modified with the above polybutadiene elastomer exhibits a maximum value of loss coefficient at the temperature region near the room temperature. This region is much higher than that of the conventional epoxy resin modified with polybutadiene elastomer mainly including 1,4-linked unit. Decrease in elastic modulus of the epoxy resin with increase of temperature is lesser in the epoxy resin of the present invention, whereas larger in the conventional one. Thus compatibility between large internal loss and high elastic modulus is achieved.

Abstract: A diaphragm for capacitance type loudspeaker is disclosed. The diaphragm uses a conductive high polymer layer as a conductor formed on a high molecular film of PET or the like by treating the high molecular film in a water solvent solution containing a conductive high molecular monomer, a chemical oxidizer and a dopant. The conductive high molecular monomer is selected from the group consisting of pyrrole, aniline, thiophene and derivatives thereof.

Abstract: A loudspeaker apparatus includes a diaphragm, a driving part driving a diaphragm, a detecting part and a coupling member. The driving part includes a voice coil bobbin mounted on the diaphragm, a voice coil wound about the voice coil bobbin and a driving magnetic circuit generating a driving power driving the diaphragm along with the voice coil. The detecting part has its terminal voltage changed responsive to the rate of displacement of the diaphragm or the voice coil bobbin. The detecting part has a detection bobbin about which a detection coil is wound and a detection magnetic circuit for detecting displacement of the diaphragm or the voice coil bobbin along with the detection coil. The connecting member is cup-shaped and formed of a liquid crystal polymer material. The coupling member has its surface smoothly curved from the outer lateral side towards the center.

Abstract: An acoustic diaphragm employed in a speaker or the like and a method for producing the acoustic diaphragm are disclosed. A diaphragm substrate is a diaphragm exhibiting air permeability such as a paper diaphragm. The substrate is processed with filling by microfibrilated pulp. For filling, the substrate is immersed in the liquid dispersion of the microfibrilated pulp and the pulp is deposited on the substrate under suction. When the microfibrilated pulp is deposited on the substrate under suction, any voids present in the substrate are closed by the microfibrilated pulp so that air tightness is improved without lowering the sound quality or detracting from desirable properties of the diaphragm, such as low density, high toughness and low losses.

Abstract: A surface (1S), on which a recording layer of an optical recording disk (1) consisting of a resin material having the recording layer is provided, is polished by a polishing member (2), obtained by processing into a cylindrical shape a polishing sheet produced by mixing a supporting material with abrasive grains and an adhesive agent for hot-pressing, while supplying water thereto, to thereby take out a resin material. One of a reaction modifier, a compatible resin and a rubber component is added to the reclaimed resin material.

Abstract: An acoustic diaphragm employed in a speaker or the like and a method for producing the acoustic diaphragm are disclosed. A diaphragm substrate is a diaphragm exhibiting air permeability, such as a paper diaphragm. The substrate is processed with filling by microfibrillated pulp. For filling, the substrate is immersed in the liquid dispersion of the microfibrillated pulp and the pulp is deposited on the substrate under suction. When the microfibrillated pulp is deposited on the substrate under suction, any voids present in the substrate are closed by the microfibrillated pulp so that air tightness is improved without lowering the sound quality or detracting from desirable properties of the diaphragm, such as low density, high toughness and low losses.

Abstract: An acoustic diaphragm is obtained by forming micro-fibrillated cellulose into a web by a process similar to a paper-making process. The micro-fibrillated cellulose is the cellulose obtained by beating to the Canadian standard freeness of not more than 300 ml, or bacterial cellulose. Since the micro-fibrillated cellulose is poor in wet strength, it is reinforced by a reinforcement element and, in this state, is formed into the web on a wire screen. The reinforcement element may be detached after forming the web, or may be left laminated with the cellulose web so that the resulting composite product is used as the acoustic diaphragm.