Abstract: A loudspeaker includes two first magnetic portions arranged in parallel and a second magnetic portion disposed between the two first magnetic portions on a bottom plate. An annular top plate is provided to the two first magnetic portions and disposed in such a manner as to form a magnetic gap with respect to the second magnetic portion. The first magnetic portions and the second magnetic portion are magnetized in the opposite directions in a direction in which the bottom plate, the first magnetic portions and the top plate are stacked. The top plate includes two main bodies provided to the two first magnetic portions and two bending portions connecting between two first magnetic portions and bending toward the bottom plate.

Abstract: A loudspeaker includes two first magnetic portions arranged in parallel and a second magnetic portion disposed between the two first magnetic portions on a bottom plate. An annular top plate is provided to the two first magnetic portions and disposed in such a manner as to form a magnetic gap with respect to the second magnetic portion. The first magnetic portions and the second magnetic portion are magnetized in the opposite directions in a direction in which the bottom plate, the first magnetic portions and the top plate are stacked. The top plate includes two main bodies provided to the two first magnetic portions and two bending portions connecting between two first magnetic portions and bending toward the bottom plate.

Abstract: A loudspeaker includes a back panel and a plurality of thin loudspeakers mounted onto the back panel. The back panel has an aspect ratio of 6 or higher, and has a wiring unit formed thereon and wire-connecting the thin loudspeakers. The thin loudspeakers are arranged on the back panel in series in a straight line. Accordingly, a thin-type loudspeaker can be realized.

Abstract: A loudspeaker includes a back panel and a plurality of thin loudspeakers mounted onto the back panel. The back panel has an aspect ratio of 6 or higher, and has a wiring unit formed thereon and wire-connecting the thin loudspeakers. The thin loudspeakers are arranged on the back panel in series in a straight line. Accordingly, a thin-type loudspeaker can be realized.

Abstract: A plate material is drawn into the shape of a rectangular dish and the peripheral border of each corner is press worked. A yoke is fabricated which has an outwardly projecting tongue-like flange provided at a position a predetermined distance below the top end surface. A frame made of resin is insert molded in a manner covering the flange. A magnet is secured inside the yoke and a magnetic circuit having magnetic gap is formed. A diaphragm joined with a voice coil is joined with the frame. By making a loudspeaker in this way, the bonding strength between the yoke and the frame is enhanced and a low-profile loudspeaker is achieved. Also, clearance at each corner of the yoke is eliminated, and a loudspeaker that is free from magnetic flux leakage and excellent both in quality and performance is obtained.

Abstract: An edge (29) for supporting a diaphragm assembly (100) with respect to a frame (26) is bonded to the frame (26) along the outer periphery thereof and joined to a diaphragm (27) in a position more peripherally inward than a voice coil (28) along the inner periphery thereof. The edge (29) partly overlaps diaphragm (27). This structure allows downsizing of the speaker, without reducing the sizes of a permanent magnet (21) and the edge (29).

Abstract: A loudspeaker includes a magnetic circuit having a magnetic gap, a frame coupled to the magnetic circuit, a voice coil having a first end positioned in the magnetic gap and a second end opposite to the first end, and a diaphragm coupled to the second end of the voice coil and the frame. The voice coil has a center axis provided through the first end and the second end. The diaphragm has a first portion in which the center axis of the voice coil is provided. The first portion of the diaphragm is provided inside the voice coil. The diaphragm further has a second portion outside the voice coil. One of the first portion and the second portion of the diaphragm has a cross section in a plane including the center axis, and the cross section of the one of the first portion and the second portion of the diaphragm has an elliptic-arc shape. This loudspeaker has a small thickness, has a high sound pressure level in a high frequency range, and secures a wide reproduction range in high frequencies.

Abstract: An electro-acoustic transducer has a magnetic circuit, a frame, a diaphragm, a voice coil, a terminal, and a stopper. The frame is joined to a magnetic circuit. The diaphragm is joined to a circumferential edge of the frame. The voice coil is joined to the diaphragm and is partially provided at a magnetic gap of the magnetic circuit. The terminal is composed of a metal plate having spring property and conductivity, is partially fixed to the frame, and is electrically connected to the voice coil. The stopper is provided at an outer periphery of the metal plate of the terminal and extends from a main section of the terminal to the frame. The stopper restricts a bending range of the metal plate constituting the terminal to a level equal to or lower than a reversibility limit value of a metal material constituting the terminal.

Abstract: A plate material is drawn into the shape of a rectangular dish and the peripheral border of each corner is press worked. A yoke is fabricated which has an outwardly projecting tongue-like flange provided at a position a predetermined distance below the top end surface. A frame made of resin is insert molded in a manner covering the flange. A magnet is secured inside the yoke and a magnetic circuit having magnetic gap is formed. A diaphragm joined with a voice coil is joined with the frame. By making a loudspeaker in this way, the bonding strength between the yoke and the frame is enhanced and a low-profile loudspeaker is achieved. Also, clearance at each corner of the yoke is eliminated, and a loudspeaker that is free from magnetic flux leakage and excellent both in quality and performance is obtained.

Abstract: An edge (29) for supporting a diaphragm assembly (100) with respect to a frame (26) is bonded to the frame (26) along the outer periphery thereof and joined to a diaphragm (27) in a position more peripherally inward than a voice coil (28) along the inner periphery thereof. The edge (29) partly overlaps diaphragm (27). This structure allows downsizing of the speaker, without reducing the sizes of a permanent magnet (21) and the edge (29).

Abstract: An electro-acoustic transducer has a magnetic circuit, a frame, a diaphragm, a voice coil, a terminal, and a stopper. The frame is joined to a magnetic circuit. The diaphragm is joined to a circumferential edge of the frame. The voice coil is joined to the diaphragm and is partially provided at a magnetic gap of the magnetic circuit. The terminal is composed of a metal plate having spring property and conductivity, is partially fixed to the frame, and is electrically connected to the voice coil. The stopper is provided at an outer periphery of the metal plate of the terminal and extends from a main section of the terminal to the frame. The stopper restricts a bending range of the metal plate constituting the terminal to a level equal to or lower than a reversibility limit value of metal material constituting the terminal.

Abstract: An edge (29) for supporting a diaphragm assembly (100) with respect to a frame (26) is bonded to the frame (26) along the outer periphery thereof and joined to a diaphragm (27) in a position more peripherally inward than a voice coil (28) along the inner periphery thereof. The edge (29) partly overlaps diaphragm (27). This structure allows downsizing of the speaker, without reducing the sizes of a permanent magnet (21) and the edge (29).

Abstract: A portable electronic device includes an electronic component, a spring terminal extending from the electronic component to supply power to the electronic component, a circuit component having a power supply section contacting the spring terminal, and a stopper for restricting a movement of the electronic component. The spring terminal has a reversible deformation limit of elastic deformation. The stopper restricts the movement of the electronic component within the reversible deformation limit of the spring terminal. This portable electronic device prevents a spring pressure of the spring terminal from decreasing, hence supplying power to the electronic component stably.

Abstract: A loudspeaker used mainly for mobile communication equipment such as a mobile telephone and having two loudspeaker parts provided in one frame is provided. In the loudspeaker, a yoke has a groove portion and a second voice coil disposed in this groove portion drives a second diaphragm. Since the groove portion functioning as a magnetic gap is formed by processing the yoke, variation in the magnetic gap, which conventionally occurred at the time of incorporation, is eliminated and accuracy is improved, thus stabilizing the sound pressure frequency property.

Abstract: An electro-acoustic transducer wherein a stopper of a terminal is composed of an elastic body having an impulsive-force resistance and an excellent resilience. The stopper is mounted on the yoke or lower plate of magnetic circuit, which is made of a metallic material having an impulsive-force resistance. In this way, the stopper can restrict the terminal within the reversibility limit value of the spring force of the metallic material, and hence can enhance the reliability.

Abstract: A portable electronic device includes an electronic component, a spring terminal extending from the electronic component to supply a power to the electronic component, a circuit component having a power supply section contacting the spring terminal, and a stopper for restricting a movement of the electronic component. The spring terminal has a reversible deformation limit of elastic deformation. The stopper restricts the movement of the electronic component within the reversible deformation limit of the spring terminal. This portable electronic device prevents a spring pressure of the spring terminal from decreasing, hence supplying a power to the electronic component stably.

Abstract: An edge (29) for supporting a diaphragm assembly (100) with respect to a frame (26) is bonded to the frame (26) along the outer periphery thereof and joined to a diaphragm (27) in a position more peripherally inward than a voice coil (28) along the inner periphery thereof. The edge (29) partly overlaps diaphragm (27). This structure allows downsizing of the speaker, without reducing the sizes of a permanent magnet (21) and the edge (29).

Abstract: A loudspeaker includes a magnetic circuit having a magnetic gap, a frame coupled to the magnetic circuit, a voice coil having a first end positioned in the magnetic gap and a second end opposite to the first end, and a diaphragm coupled to the second end of the voice coil and the frame. The voice coil has a center axis provided through the first end and the second end. The diaphragm has a first portion in which the center axis of the voice coil is provided. The first portion of the diaphragm is provided inside the voice coil. The diaphragm further has a second portion outside the voice coil. One of the first portion and the second portion of the diaphragm has a cross section in a plane including the center axis, and the cross section of the one of the first portion and the second portion of the diaphragm has an elliptic-arc shape. This loudspeaker has a small thickness, has a high sound pressure level in a high frequency range, and secures a wide reproduction range in high frequencies.

Abstract: A loudspeaker used mainly for mobile communication equipment such as a mobile telephone and having two loudspeaker parts provided in one frame is provided. In the loudspeaker, a yoke has a groove portion and a second voice coil disposed in this groove portion drives a second diaphragm. Since the groove portion functioning as a magnetic gap is formed by processing the yoke, variation in the magnetic gap, which conventionally occurred at the time of incorporation, is eliminated and accuracy is improved, thus stabilizing the sound pressure frequency property.