Star Micronics Company Limited

Star Micronics., Ltd.

Motoaki Ito

Yoshio Imahori

Kentaro Yonehara

Hiroshi Fujinami

Yasunori Tsukuda

Yoshiaki Tsukiji

Yoshiyo Wada

A circuit board forming member, a case forming member, a spacer forming member, a diaphragm sheet and a diaphragm plate forming member are laminated to form a portion, as excepting a back plate and a contact spring, of a condenser microphone, in plurality in a laminate. Moreover, the back plate and the contact spring are arranged in the air chamber, which is defined by the individual forming members, to form a plurality of condenser microphone constituents in the laminate. Next, the laminate is cut to separate the individual condenser microphone constituents thereby to manufacture the condenser microphones.

Method for manufacturing condenser microphone

By integrating plural condenser microphone constituting bodies in an array state, a condenser microphone array is obtained. The condenser microphone array is formed by dicing a laminate of a circuit board forming member, a housing forming member, a spacer forming member, diaphragm sheet, diaphragm plate forming member and a cover forming member which form a part of the plural condenser microphone constituting bodies respectively. In an air chamber of each condenser microphone constituting body constituted in the laminate, a back plate and a contact spring are built.

Microphone array

A method for producing an electret capacitor microphone high in sensitivity and stable in acoustic characteristic. A PET film stretched with predetermined tension is bonded to a diaphragm support ring to perform stretch and fixation of a diaphragm to produce a diaphragm sub-assembly. The diaphragm sub-assembly is heated at a predetermined temperature (e.g. 200&#xb0; C.) higher than a second order transition point of PET. Then, the diaphragm sub-assembly is packed in a housing. Because the diaphragm sub-assembly is heated at the predetermined temperature before packed in the housing, the stiffness of the diaphragm is reduced. Because the stiffness of the diaphragmis reduced in such a manner, the tension at the time of stretch and fixation of the diaphragm can be set to a large value to prevent the diaphragm from being crinkled.

Electret capacitor microphone and method for producing the same

Electroacoustic transducer

In a microphone having a microphone body stored in a substantially cylindrical metal casing, the casing per se is formed as a ground terminal while a plus terminal is disposed in the center of a lower end surface of the microphone body. A holder is formed to have a bottom wall portion extending from a lower end portion of the holder to a lower end surface of the microphone. An outer circumferential edge portion and a center portion of the bottom wall portion are made of electrically conductive rubber so as to serve as first and second electrically conductive portions electrically connected to the two terminals respectively. Sufficient contact areas of the two electrically conductive portions with electrically conductive patterns of an external board is obtained while a sufficient gap is ensured between the two electrically conductive portions.

Holder used in the microphone unit

To provide an electret capacitor microphone in which change of sensitivity characteristic caused by thermal deformation of an electret layer can be prevented even in the case where a reflow process is carried out. An electret capacitor microphone includes: an electret capacitor portion including a diaphragm, and a back electrode plate disposed opposite to the diaphragm through a spacer; an electrically insulating bush for electrically insulating/supporting an outer circumferential edge portion of the back electrode plate; a metal cover in which the electret capacitor portion and the electrically insulating bush are stored; and a gate spring having a pressing function for elastically pressing the back electrode plate toward the diaphragm to form a predetermined gap between the electrically insulating bush and an inner surface of a rear wall of the metal cover. Consequently, collapse of a spacer-abutting portion of an electret layer is prevented from being caused by thermal expansion.

Electret capacitor microphone

An electret capacitor microphone includes an electret capacitor section having a diaphragm and a backplate, an impedance conversion element for converting a change in the electrostatic capacity of the electret capacitor section into an electric impedance, and a case for accommodating the electret capacitor section and the impedance conversion element. Part of the case is a synthetic resin-made base member formed integrally with a plurality of terminal members by insert molding. One end of the terminal member is exposed on an inner surface of the base member so as to form part of a conductive pattern. The other end of the terminal member is exposed on an outer surface of the base member as an external connection terminal portion. The impedance conversion element is mounted on the base member at a predetermined position in the conductive pattern.

A capacitor microphone includes a case having an end wall defining an opening for a sound hole, a capacitor portion comprising a diaphragm, a back plate and a spacer, the diaphragm opposing to the back plate via the spacer, the capacitor portion being accommodated in the case in such an manner as the diaphragm is placed on the side of the end wall, and a substrate accommodated in the case farther from the end wall than the capacitor portion, the substrate having an impedance conversion element mounted on a surface thereof facing the capacitor portion. A communicating opening is provided around the back plate in a position opposing to the impedance conversion element for communicating spaces on the front and back sides of the back plate. The communicating opening has a larger area than that of the top of the impedance conversion element to allow the spaces on both sides of the back plate to communicate with each other. It is possible to ensure that the impedance element and the back plate do not interfere with each other.

Capacitor microphone

An ultrasonic motor,comprises a stator-side elastic member,having a rotationally symmetrical shape, a rotor-side elastic member,having a rotationally symmetrical shape, a stator-side piezoelectric element,for imparting vibrations to the elastic member,a rotor-side piezoelectric element,for imparting vibrations to the elastic member,an output shaft,rotating integrally with the elastic member,a rotary transformer,for supplying power to the piezoelectric element,in non-contacting fashion, and housings,and,for accommodating therein the above-enumerated elements, wherein of three transformer circuits in the rotary transformer,a middle transformer circuit C,and an outermost transformer circuit C,are used as a two-phase drive power transformer circuit. This construction achieves stable power supply to the rotor side.

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Shizuoka, Japan

Motoaki Ito