Abstract: The receiver unit includes a receiver body, a housing containing this receiver body, a cord connected to the receiver body, and a cord protector for protecting the cord. The cord protector is a plate-like member having a substantially rectangular shape, and includes an engaging portion and a semicircular portion. The cord protector is formed of soft material such as urethane rubber having Shore hardness of about A90, and its wall thickness is set to be 0.3 to 0.6 mm (0.5 mm, for example).

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: 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 receiver unit includes a receiver body, a housing containing this receiver body, a cord connected to the receiver body, and a cord protector for protecting the cord. The cord protector is a plate-like member having a substantially rectangular shape, and includes an engaging portion and a semicircular portion. The cord protector is formed of soft material such as urethane rubber having Shore hardness of about A90, and its wall thickness is set to be 0.3 to 0.6 mm (0.5 mm, for example).

Abstract: An electronic device is configured so that a top housing, in which a receiver is incorporated, and a bottom housing, in which a microphone is incorporated, are connected by a positive terminal to each other, and that the housings support each other through the positive terminal. A circuit board is disposed on the positive terminal. The receiver is incorporated into the top housing. The microphone is incorporated into the bottom housing. These housings are connected by the positive terminal. The incorporation of components and the wiring there among can be facilitated.

Abstract: An insert earphone which prevents a sound leakage and improves wearing comfort. An ear chip has a barrel portion and first and second annular flange portions having the shape of a parabola spreading from the top toward the middle and from the middle toward the base of the barrel portion respectively. The first annular flange portion has a smaller outer diameter than the second annular flange portion. The first annular flange portion has almost even thickness from the inner circumference to the outer circumference, and has the inner circumference neighborhood substantially formed in the shape of a sliced doughnut.

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: An insert earphone which prevents a sound leakage and improves wearing comfort. An ear chip has a barrel portion and first and second annular flange portions having the shape of a parabola spreading from the top toward the middle and from the middle toward the base of the barrel portion respectively. The first annular flange portion has a smaller outer diameter than the second annular flange portion. The first annular flange portion has almost even thickness from the inner circumference to the outer circumference, and has the inner circumference neighborhood substantially formed in the shape of a sliced doughnut.

Abstract: An insert earphone which attains desired acoustic characteristics. A receiver unit having a sound passage tube comprises a receiver main body and a housing accommodating the receiver main body. The sound passage tube includes an outer tube portion integrally formed with a frame of the housing and an inner tube member inserted into an inner space of the outer tube portion. The inner tube member is provided separately from the frame. A sound passage can be easily defined in any shape to obtain a desired acoustic characteristics. Plural kinds of insert earphones having different acoustic characteristics are manufactured by preparing plural kinds of inner tube members. This contributes to reduction in cost compared with a case of manufacturing plural kinds of frames.

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: An electroacoustic transducer, which has a diaphragm, a support member for supporting the diaphragm, a pole piece placed inside the support member and comprising a core and a base, a coil wound around the core, and a magnet placed between the support member and the coil, in which the diaphragm is made of resin to which a magnetization is applied.

Abstract: An electroacoustic transducer, which has a diaphragm, a support member for supporting the diaphragm, a pole piece placed inside the support member and comprising a core and a base, a coil wound around the core, and a magnet placed between the support member and the coil, in which the pole piece or at least the core thereof is made of resin to which a magnetization is applied.

Abstract: A printed circuit terminal includes a main terminal body and an integrally formed fixing portion that is coaxial with the terminal body for mounting the terminal to a printed circuit base member. A frusto-conical flange is integrally connected between the body and the fixing portion and has a peripheral surface located in radially outward relation to the body and the fixing portion. The flange includes two surface portions. The first surface portion is adapted to contact and extend from the base member for receiving solder deposited in electrical contact with the base member. A second surface portion is axially adjacent to the first portion and exposes a different surface material than the first portion in order to restrain solder adhesion to the second surface portion.

Abstract: The invention provides an electroacoustic transducer capable of preventing degradation in its acoustic performance as a result of the reflow soldering process applied. With the electroacoustic transducer, variation in the minimum resonance frequency Fo of a diaphragm is restrained, stabilizing the acoustic performance by causing a decrease in the minimum resonance frequency Fo of the diaphragm due to irreversible demagnetization of the magnet caused by the reflow soldering temperatures to cancel out an increase in the minimum resonance frequency Fo of the diaphragm due to thermal contraction of a holder member caused by the reflow soldering temperatures.

Abstract: The present invention provides a small electroacoustic transducer which is improved in sound characteristic by enlarging and adjusting a volume of a resonance space. A second resonant chamber as an auxiliary space is formed relative to a first resonant chamber formed in front of a resonance plate, wherein the first and second resonant chambers are connected with each other to enlarge the volume of the resonant volume.

Abstract: The invention provides a miniaturized and low-profile electroacoustic transducer. In the electroacoustic transducer, a space is formed underneath a magnet by diminishing a vertical thickness of the magnet in comparison with the height of a magnetic core, and also by disposing the magnet at a position trensversely aligned to an upper portion of the magnetic core, so that the space is utilized as a part of a back space at the back of a diaphragm, and for connection of terminals of a coil with external terminals, thereby realizing miniaturization and flattening in the shape of the electroacoustic transducer.

Abstract: The invention provides an electroacoustic transducer wherein the resonant chamber is given a space and volume necessary for resonance and the vibration system is given an efficient air damping effect and thereby undesired vibrations are suppressed with the resonant effect maintained. The electroacoustic transducer according to the invention is provided with a resonant chamber for resonating with the vibration of a diaphragm and a sound ejecting hole for communicating the resonant chamber with the outside air formed on a position off to the central axis of the diaphragm. Furthermore, an air damping means for compensating the lowering of the air damping effect due to the dislocation of the sound ejecting hole from the central axis of the diaphragm is provided on the inner wall of the resonant chamber so as to surround the central axis of the diaphragm.