Abstract: A loudspeaker diaphragm includes a cone having a curved surface from the outer to the inner periphery, and an annular edge of which inner peripheral part is bonded to the front side of the outer peripheral part of the cone. When seen from the front, the outer periphery of the cone is defined by smooth connection of three larger-diameter parts tangent to a first circle with a larger diameter, and three smaller-diameter parts each located between adjacent two of the three larger-diameter parts and tangent to a second circle with a smaller diameter. In the cone, a shape defined by connecting together points at the same position on the central axis is more circular as the points approach the inner periphery from the outer periphery. The inner periphery of the edge has a smaller radius than the second circle.

Abstract: A loudspeaker diaphragm includes a cone having a curved surface from the outer to the inner periphery, and an annular edge of which inner peripheral part is bonded to the front side of the outer peripheral part of the cone. When seen from the front, the outer periphery of the cone is defined by smooth connection of three larger-diameter parts tangent to a first circle with a larger diameter, and three smaller-diameter parts each located between adjacent two of the three larger-diameter parts and tangent to a second circle with a smaller diameter. In the cone, a shape defined by connecting together points at the same position on the central axis is more circular as the points approach the inner periphery from the outer periphery. The inner periphery of the edge has a smaller radius than the second circle.

Abstract: A loudspeaker includes a frame, a magnetic circuit provided with a magnetic gap, a cone-shaped diaphragm, a voice coil, and an LED. The magnetic circuit is connected to a lower part of the frame. The diaphragm is connected to an outer periphery of the frame. A first end of the voice coil is connected to the diaphragm, and a second end thereof is inserted into the magnetic gap. The LED is provide on an upper part of the frame, and outputs light toward the center of the diaphragm. The LED is disposed such that the diaphragm reflects the light.

Abstract: A loudspeaker includes a frame, a magnetic circuit provided with a magnetic gap, a cone-shaped diaphragm, a voice coil, and an LED. The magnetic circuit is connected to a lower part of the frame. The diaphragm is connected to an outer periphery of the frame. A first end of the voice coil is connected to the diaphragm, and a second end thereof is inserted into the magnetic gap. The LED is provide on an upper part of the frame, and outputs light toward the center of the diaphragm. The LED is disposed such that the diaphragm reflects the light.

Abstract: The present invention relates to a loudspeaker in the acoustic field and the information communication field. The invention provides a loudspeaker that can realize a thinner size. To achieve this, the loudspeaker of the present invention is structured so that a part of a diaphragm is inserted to a dent or an opening formed at the center poles of a lower plate of a magnetic circuit. This structure allows the diaphragm to be stored within the height of the magnetic circuit, thus allowing the loudspeaker to have a thinner size.

Abstract: The present invention relates to a loudspeaker in the acoustic field and the information communication field. The invention provides a loudspeaker that can realize a thinner size. To achieve this, the loudspeaker of the present invention is structured so that a part of a diaphragm is inserted to a dent or an opening formed at the center poles of a lower plate of a magnetic circuit. This structure allows the diaphragm to be stored within the height of the magnetic circuit, thus allowing the loudspeaker to have a thinner size.

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 electroacoustic transducer has a magnetic circuit, a frame combined with the magnetic circuit, a diaphragm combined with a periphery of the frame, a voice coil, a terminal, and a holder covering the frame. The voice coil is combined with the diaphragm and a part of the voice coil is arranged in a magnetic gap of the magnetic circuit. The terminal, made of a metal plate having spring property and electric conductivity, electrically connects an outside circuit and the voice coil utilizing spring pressure generated when the metal plate is bent. The holder forms a stopper for restricting a bend of the metal plate forming the terminal to within a reversible limit of a metallic material.

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 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 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: In an electro-acoustic converter, a frame is bonded to the magnetic circuit, and the diaphragm is bonded to a circumferential edge of the frame. The voice coil is attached to the diaphragm and a part thereof is located in a magnetic gap of the magnetic circuit. The terminal is made of a sheet metal having spring property and electrical conductivity, and a part thereof is fixed to the frame. The terminal has a bent portion and a contact portion, and is electrically connected to the voice coil. The stopper is provided around a portion of the terminal at one side nearer to the frame than the bent portion, and protrudes from a surface of the frame where the contact portion of the terminal protrudes. The stopper restricts bending of the terminal to an extent within a threshold value of reversibility of a material the sheet metal.

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: The present invention relates to a loudspeaker in the acoustic field and the information communication field. The invention provides a loudspeaker that can realize a thinner size. To achieve this, the loudspeaker of the present invention is structured so that a part of a diaphragm is inserted to a dent or an opening formed at the center poles of a lower plate of a magnetic circuit. This structure allows the diaphragm to be stored within the height of the magnetic circuit, thus allowing the loudspeaker to have a thinner size.

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: An electroacoustic transducer has a magnetic circuit, a frame combined with the magnetic circuit, a diaphragm combined with a periphery of the frame, a voice coil, a terminal, and a holder covering the frame. The voice coil is combined with the diaphragm and a part of the voice coil is arranged in a magnetic gap of the magnetic circuit. The terminal, made of a metal plate having spring property and electric conductivity, electrically connects an outside circuit and the voice coil utilizing spring pressure generated when the metal plate is bent. The holder forms a stopper for restricting a bend of the metal plate forming the terminal to within a reversible limit of a metallic material.

Abstract: Electro-acoustic converter (35) such as a speaker includes frame (26) attached to magnetic circuit member (24), diaphragm (27) attached to frame (26), voice coil (28) attached to this diaphragm (27) and having a part of which disposed in magnetic gap (25) in magnetic circuit member (24), terminal (30) made by bending a metal plate and being brought into contact with a power supply unit of an electronic device in which electro-acoustic converter (35) is installed by utilizing a spring pressure of this metal plate, and stopper (29) restricting bending of the metal plate forming this terminal (30) within a reversible limit of its metal material.