Abstract: 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.

Abstract: In an electroacoustic transducer, a pair of coil terminals elongating from a voice coil are electrically connected to a pair of terminal members attached to a frame via a flexible printed circuit board, respectively. According to the configuration, even in a case where an electroacoustic transducer is used at a high sound pressure, breakage of the coil terminals hardly occurs. In the flexible printed circuit board, the width of an intermediate portion is set to be smaller than the widths of an end portion on the side of the coil terminals and an end portion on the side of the terminal members. Therefore, the flexibility of the intermediate portion can be enhanced, whereby transmission of characteristic vibration of the flexible printed circuit board to a diaphragm, and stress concentration in the vicinity of the end portions are effectively suppressed.

Abstract: The two coil spring terminals have the structure of double coil spring terminal including a small diameter coil spring terminal and a large diameter coil spring terminal. In this case, a terminal holder is provided with a clamping portion for clamping the large diameter coil spring terminal between the terminal holder and an internal circuit board. Specifically, the terminal holder is formed, in an upper end portion of its outer peripheral surface, with an annular groove which is adapted to be engaged with a small diameter portion formed in an upper end portion of the large diameter coil spring terminal. This omits fixation of the large diameter coil spring terminal to the internal circuit board, and necessity of soldering the two coil spring terminals respectively to the internal circuit board as a conventional art, enhancing mounting workability of the terminal holder.

Abstract: 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.

Abstract: 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.

Abstract: An electromagnetic receiver of a balanced armature type is employed as a receiver to be mounted in a portable telephone. The balance armature receiver has lower power consumption and higher electric acoustic conversion efficiency. The balanced armature receiver provides a required output even though small in size. The receiver occupies a considerably reduced space in the portable telephone, compared with a conventional portable telephone having a conventional dynamic receiver. The longitudinal wall of the receiver is parallel to the upper edge of a liquid crystal display panel, so that the liquid crystal display panel is extended upward and considerably enlarged.

Abstract: 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.

Abstract: A low cost dynamic speaker (10) prevents damage of the diaphragm (16) when the speaker (10) is mounted on a printed circuit board (2). An insulating ring (22) is attached to the front surface of the diaphragm (16) at the periphery. The insulating ring (22) has a pair of terminal pins (24) supported thereon for continuity of the lead wire (18a) with the conductor (4) of the printed circuit board (2). The conducting portion (24b) of each of the terminal pins (24) is protruded forward beyond the annular flat surface (22a) of the insulating ring (22).

Abstract: An electroacoustic transducer adapted to be mounted on a printed circuit board in which a coil spring is accommodated and supported in a cylindrical recess of a frame while it is fixed to neither a terminal plate nor the frame. Particularly, a protruding pin of the coil spring is passed through a though hole of the terminal plate to allow a leading portion of the protruding pin to be hooked thereon. When the electroacoustic transducer is mounted on the printed circuit board, any horizontal displacement between the compressed spring and the printed circuit board would not cause stress concentration on the coil spring since the coil spring is onlly horizontally shifted in the cylindrical recess until a coil portion of the coil spring hits against the wall of the cylindrical recess.

Abstract: A diaphragm subassembly comprises a voice coil, a diaphragm, a frame, and a pair of terminal members. A magnetic circuit unit comprises a yoke, a magnet, and a base. The diaphragm subassembly and the magnetic circuit unit are accommodated in a bottomed cylindrical cover. In the manufacturing process, the cover is placed with the open end directed upward. The diaphragm subassembly, the yoke, the magnet, and the base are dropped into the cover in this order. The manufacturing process of a dynamic electroacoustic transducer is thereby simplified.

Abstract: The diaphragm is supported by the frame at the outer edge thereof. The pair of terminal members is mounted on the frame, and a pair of lead wire drawn from the voice coil is fixed to the land portion of the terminal member for electrical continuity. Since the land portion is disposed on the upper side of the frame, fixation of the lead wire can be performed without turning the frame upside down. This simplifies the manufacturing process of the speaker and also prevents a breakage of the lead wire that conventionally happens when the frame is turned upside down. Further, this prevents the operator from touching the lead wire since no part of the lead wire is exposed outside the frame after the fixation.

Abstract: An electroacoustic transducer (1) includes a base (24) and magnetic core (22) a diaphragm (20) supported with a gap between the diaphragm and a forward end of the magnetic core, a magnet (25) constituting a magnetic circuit together with the base (24), the magnetic core (22) and the diaphragm (20) a coil (23) disposed around the magnetic core a coil bobbin (30) for holding the coil (23), a housing (10) for receiving the above-mentioned members, a filler (19) applied to an external surface side of the base (24), and lead terminals (41 and 42) for supplying an electric current. The lead terminals (41 and 42) have protrusion portions (41a and 42a, protruding into an internal surface side of the base (24) in the axial direction of the coil. A coil wire (23a) is wound around the protrusion portions (41a and 42a) so as to be connected to the lead terminals (41 and 42).

Abstract: 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.

Abstract: A speaker holder includes a speaker engagement portion (52) abutting the bottomed cylindrical portion (26A) of the frame (26) of the speaker (10) and a plurality of engagement legs (54) extending from the speaker engagement portion (52). The speaker (10) is disposed tightly between the speaker engagement portion (52) and the printed circuit board (2) and fixed thereto via the engagement legs (54).

Abstract: Fixing of a voice coil (16) to a diaphragm (12) is performed by caulk-fixing a coil supporting member (26) to the diaphragm (12) and by fit-supporting the voice coil (16) by the coil supporting member (26). Hereby, the voice coil 16 is physically fixed to the diaphragm (12) and its fixing strength is heightened. The caulk-fixing is performed by subjecting a caulking projection of the coil supporting member (26) to a plastic deformation thereby to provide a caulk-fixed portion (26b), whereby deformation injurious to the acoustic property does not occur in the diaphragm (12). Further, the fit-supporting is performed by interposing a flange portion (16a1) formed at an upper end portion (16a) of the voice coil (16) between an engaging portion (26a) of the coil supporting member (26) and a central flat portion (12b) of the diaphragm (12) and holding it by them from upper and lower sides.

Abstract: 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.

Abstract: An electroacoustic transducer adapted to be mounted on a printed circuit board in which a coil spring is accommodated and supported in a cylindrical recess of a frame while it is fixed to neither a terminal plate nor the frame. Particularly, a protruding pin of the coil spring is passed through a though hole of the terminal plate to allow a leading portion of the protruding pin to be hooked thereon. When the electroacoustic transducer is mounted on the printed circuit board, any horizontal displacement between the compressed spring and the printed circuit board would not cause stress concentration on the coil spring since the coil spring is onlly horizontally shifted in the cylindrical recess until a coil portion of the coil spring hits against the wall of the cylindrical recess.

Abstract: An electroacoustic transducer to be mounted on a board of a device, includes an anode conductive part which is in press contact with the board of the device, and a cathode conductive part which is in press contact with the board of the device, wherein the anode conductive part and the cathode conductive part are respectively placed at an axial center position or at predetermined positions in a radial direction to eliminate directionality in a circumferential direction.

Abstract: A frame (14) supporting a diaphragm (12) by its outer periphery is constructed by a connecting ring (30) and a base (28) which comprises a bottomed cylinder portion (28A) and a mounting portion (28B) which extends radially outward from the bottomed cylinder portion (28A) which is a part of the magnetic circuit unit (18). The connection is achieved by the caulking of the ring (30) and the mounting portion (28B) with the diaphragm (12) clamped therebetween.

Abstract: The diaphragm is supported by the frame at the outer edge thereof. The pair of terminal members is mounted on the frame, and a pair of lead wire drawn from the voice coil is fixed to the land portion of the terminal member for electrical continuity. Since the land portion is disposed on the upper side of the frame, fixation of the lead wire can be performed without turning the frame upside down. This simplifies the manufacturing process of the speaker and also prevents a breakage of the lead wire that conventionally happens when the frame is turned upside down. Further, this prevents the operator from touching the lead wire since no part of the lead wire is exposed outside the frame after the fixation.