Yamaha Corporation

Yupo Corporation

Kunio Hiyama

Hideo Suzuki

Kunimasa Muroi

Toshiharu Fukushima

Hiroshi Koike

Seiichiro Iida

Hidekazu Kodama

Tomoya Miyata

Yasutaka Nakamura

Masuhiro Okada

Rento Tanase

Masahiro Sugiura

Yutaro Sugamata

Emiko Suzuki, Legal Representative

Masao Imanishi

Hiroshi Nakashima

Atsushi Yoshida

Eizi Abe

Masaru Matsushita

Susumu Ogino

Atsushi Ohtaka

Takanori Kawamura

Suguru Sasaki

Toshihari Fukushima

Kaoru Hashimoto

Eiji Abe

Yutarou Sugamata

A speaker diaphragm includes a first polymer and a second polymer. The first polymer and the second polymer undergo phase separation. The first polymer is a polyolefin, and the second polymer is a thermoplastic resin being immiscible with the polyolefin. One of either the polyolefin or the thermoplastic resin constitutes a sea phase, and another one of either the polyolefin or the thermoplastic resin constitutes island phases being interspersed in the sea phase.

Speaker diaphragm

A sensor unit capable of protecting a piezoelectric element and detecting vibration and sound is provided. The sensor unit comprises a sheet-like piezoelectric element having a porous layer, and a sound propagation sheet covering at least one face of the piezoelectric element and permitting transmission of sound from a first face toward a second face of the sound propagation sheet. A difference in acoustic pressure level between the sound incident on the sound propagation sheet and the transmitted sound is preferably no greater than 10 dB. A surface density of the sound propagation sheet is preferably from 0.03 g/mto 100 g/m. The sound propagation sheet is preferably flexible and preferably has voids. The sensor unit preferably further comprises a sound insulation sheet covering another face of the piezoelectric element and substantially preventing transmission of sound from a second face toward a first face of the sound insulation sheet.

Sensor unit and musical instrument

Provision of a piezoelectric element which uses a lightweight and flexible electret material and an electrode layer which is also lightweight, has high conductivity and good flexibility to easily receive electrical signals from an electret, and has good durability. Additionally, provision of a musical instrument provided with such a piezoelectric element. A piezoelectric element comprising an electrode layer (B) on at least one surface of an electret material (A) having pores inside, wherein a porosity of the electret material (A) is 20 to 80%, the electrode layer (B) contains 20 to 70 mass % of a carbon fine particle, and a thickness of the electrode layer (B) is 2 to 100 &#x3bc;m.

Piezoelectric element and musical instrument

A sound absorbing structure is constituted of a housing having a hollow portion and an opening and a vibration member composed of a board or diaphragm. The vibration member is a square-shaped material having elasticity composed of a synthetic resin and is bonded to the opening of the housing, thus forming an air layer closed inside the sound absorbing structure by the housing and the vibration member. In the sound absorbing structure, when the lateral/longitudinal dimensions of the air layer and characteristics of the vibration member (e.g. a Young's modulus, thickness, and Poisson's ratio) are set such that the fundamental frequency of a vibration occurring in a bending system falls within 5% and 65% of the resonance frequency of a spring-mass system, a vibration mode having a large amplitude occurs in a frequency band lower than the resonance frequency of the spring-mass system, this improving the sound absorption coefficient.

Sound absorbing structure and vehicle component having sound absorbing property

A method for manufacturing a probe unit includes: (a) preparing a substrate; (b) forming a hollow part in the substrate; (c) forming a sacrificial layer that buries the hollow part on the substrate; (d) forming a first layer on the substrate, wherein one end of the first layer is positioned on the sacrificial layer; (e) forming a second layer on the first layer at least excepting the one end; and (f) removing the sacrificial layer.

Method for manufacturing a probe unit

In order to provide a sound-absorbing body which has both a thin thickness and improved sound-absorption characteristics with regard to a low tone range sounds, the sound-absorbing body () includes: an organic hybrid sheet () constituted from an organic low-molecular material which is spread in a matrix polymer; and a gastight air cell () which is closely provided at a backside () of the organic hybrid sheet, wherein the organic hybrid sheet indicates both a sound-absorption peak of a random incidence sound-absorption coefficient at a frequency band of 400 Hz or lower and another sound-absorption peak when the organic hybrid sheet is vibrated by applying air vibration caused by sound, because of adhering the organic hybrid sheet to the gastight air cell.

Sound absorbing body

A ribbon-shaped material for FRTP molded objects 1 having a laminate 4 in which a ribbon-shaped reinforcing fiber tow 2 is placed between thermoplastic resin films for supplying matrix resin which are wider than the ribbon-shaped reinforcing fiber tow 2, and in which the thermoplastic resin films 3,3 are fused in side portions 5,5 of the laminate 4, which are along the longitudinal direction of the laminate 4; and a wide material for FRTP molded objects 30,40 obtained by arranging a plurality of the ribbon-shaped materials for FRTP molded objects 1 whereby adjacent ribbon-shaped materials for FRTP molded objects 1,1 overlap each other in a manner such that the side portion 5 of one of the adjacent ribbon-shaped materials for FRTP molded objects 1 is placed on the side portion 5 or the middle portion 6 of the other along the longitudinal direction, and fusing together each overlapping portion 31,41 of the ribbon-shaped materials for FRTP molded objects 1, whereby the reinforcing fiber tows 2 are arranged in parallel; are advantageous in providing excellent impregnation of the reinforcing fiber with the thermoplastic resin, giving a great freedom of design, providing easy handling, creating no fuzz of the reinforcing fiber, and being flexible. Using such a material for FRTP molded objects 1,30,40, an inexpensive FRTP tubular molded object having a superior strength can be produced.

Material for FRTP molded objects and FRTP tubular molded object

A pre-impregnation has a ribbon-shaped tow of reinforcing fibers and a ribbon of thermoplastic resin laminated on the ribbon-shaped tow and fixed thereto at intervals, and the thermoplastic resin is allowed to uniformly impregnate into the ribbon-shaped tow under heat application so that a void does not take place in the ribbon-shaped tow.

Stong flexible pre-impregnation of fiber reinforced thermoplastic resin

A prepreg for a sleeve member of fiber reinforced thermoplastic resin available for a tennis racket or a golf club is woven by using ribbon-shaped reinforcing fiber tows/uni-directional commingle yarns and matrix fiber tows, and the ribbon-shaped reinforcing fiber tows/commingle yarns make the prepreg and, accordingly, the sleeve product thin, light, highly dense, economical and large in mechanical strength.

Prepreg available for fiber reinforced thermoplastic resin and process

Strong flexible pre-inpregnation of fiber reinforced thermoplastic resin

Strong flexible pre-impregnation of fiber reinforced thermoplastic resin

In the production of a hollow FRP article such as a wood type carbon black golf club head, a hollow resin shell is formed via blow molding, heat-resistant fine particles are filled as a filler into the interior of the resin shell, the interior of the resin shell is decompressed to form an inner mold, the inner mold is covered with FRP prepreg including thermoplastic resin to form a prepreg composite, the prepreg composite is heated in a metallic mold under pressure and the fine articles are removed after demolding. A golf club shaft is formed by heating a mandrel, applying thermoplastic resin powder to the mandrel and then winding a lamellar prepreg around the mandrel to thereby form a hollow shaft. A golf club is formed from a head and shaft formed as described above by enlarging the end of the shaft, placing the shaft and the head in a mold and heating the mold under pressure.

Method for producing a hollow FRP article

In construction of a liquid crystal display including an alignment film and generally used for video display panels such as television sets, the orientation wafer is given in the form of a porous alumina layer. Substantially vertical molecular orientation is resulted from penetration of liquid crystal molecules into pores in the alignment film. Optical application of rubbing process in production enables free adjustment of the value of pretilt angle. Good reproduction and stability is assured even in the case of large fields of vision.

Growing community of inventors

Hamamatsu, Japan

Kunio Hiyama