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: A net made of material containing at least metal is bonded to a protector of a loud speaker, and hence shields electromagnetic waves. Electromagnetic interference can be prevented in an electronic apparatus such as a portable phone employing the loud speaker.

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 net made of material containing at least metal is bonded to a protector of a loud speaker, and hence shields electromagnetic waves. Electromagnetic interference can be prevented in an electronic apparatus such as a portable phone employing the loud speaker.

Abstract: Net (30) made of material containing at least metal is bonded to protector (29) of a loud speaker, and hence shields electromagnetic wave. Electromagnetic interference can be prevented in an electronic apparatus such as a portable phone employing the loud speaker.

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: Shield cover (29) made of a magnetic material covers yoke (23) in internal magnetic circuit (24) of a speaker so as to reduce magnetic leakage from internal magnetic circuit (24).

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.