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: A bobbin unit includes a base portion and a coil winding portion on which a conductor is wound. A hole is formed in a central part of the base portion to allow an armature to pass through. Coil side terminals to which ends of the conductor are fixed and signal input terminals to which an external signal is entered are provided at opposite ends of the base portion with the hole located in between. The coil side terminals are electrically connected to their corresponding signal input terminals inside the base portion. A coil is formed on the coil winding portion by winding the conductor. The ends of the conductor are fixed to the respective coil side terminals.

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: A bobbin unit includes a base portion and a coil winding portion on which a conductor is wound. A hole is formed in a central part of the base portion to allow an armature to pass through. Coil side terminals to which ends of the conductor are fixed and signal input terminals to which an external signal is entered are provided at opposite ends of the base portion with the hole located in between. The coil side terminals are electrically connected to their corresponding signal input terminals inside the base portion. A coil is formed on the coil winding portion by winding the conductor. The ends of the conductor are wound around the respective coil side terminals and fixed thereto by arc welding. Since the conductor is electrically connected to the signal input terminals when the ends of the conductor are fixed to the coil side terminals, connection of the ends of the conductor constituting the coil to the signal input terminals is made easy.

Abstract: A magnetic indication sheet printing method and a magnetic indication sheet printing apparatus for printing characters and such on a magnetic indication sheet being capable of carrying out an optimum printing process without being affected by the ambient temperature and the temperature of the magnetic indication sheet. The method and the apparatus magnetically indicates characters on the magnetic indication sheet by means of a magnetic field, where the sheet is heated to an appropriate temperature.

Abstract: A magnetic display erasing apparatus is provided in which an ideal erasing magnetic field can be realized by using a small-sized magnet. A magnet is formed by bending a rectangular plate-like magnet, having the N-pole on the surface and the S-pole on the back face, into a U-shape so that the N-pole of one end of the magnet confronts the N-pole of the other end thereof symmetrically with respect to a magnetic display sheet. The magnetic display sheet is conveyed by a conveying apparatus, which is not shown, in the U-shaped gap space which is formed by the magnet. Because the magnetic field is symmetrical with respect to the plane of the magnetic display sheet, an ideal planar magnetic field is attained on the disposition plane of the magnetic display sheet. There is no point where the strength of the magnetic field is zero. Therefore, the whole region of the empty space can be used for erasure and the space utilization efficiency of the magnet is enhanced.

Abstract: A magnetic display erasing apparatus is provided wherein the distance by which an erasing head is moved when an unerasing operation is to be performed can be made as short as possible, thereby allowing the apparatus to be miniaturized and various designs obtained. A magnetic stripe an a magnetic display sheet are formed on a magnetic card. An erasing head is disposed on the side of the back face of the magnetic card which is conveyed. During an erasing operation, a magnetic field which is substantially parallel is formed at the position where the magnetic display sheet passes. When the magnetic display sheet is not to be erased, the erasing head is retracted from a card conveying path and then housed in a magnetic shield so as to be hermetically sealed. Accordingly, the magnetic field from the erasing head is weakened and cannot reach the magnetic display sheet.