Abstract: A disk player system having a disk sucking function includes a disk sucking member of a configuration defining a suction space between it and a disk and a suction channel provided for communicating the suction space with an atmosphere about a center spindle or about a peripheral portion of the disk sucking member. A suction pump provided for sucking the disk is made detachable from a turntable so that a disk sucking operation is performed before the disk is played and the suction pump is detached when the disk is played. According to the system, deterioration of quality of the reproduced signal is prevented and a sucking efficiency is improved.

Abstract: An electro-acoustic transducer comprises a planar type diaphragm having a circular voice coil formed on its surface and a magnet plate assigned for magnetically biasing said voice coil, said circular voice coil having a plurality of circular turns formed with a pattern that the respective circular turns of the circular coil are concentric to each other in at least one half portions of these turns. This arrangement of transducer makes its assembling or the positioning of the voice coil and the magnet plate extremely easy without degrading the output capability of the transducer.

Abstract: A headphone comprising: two ear cups; a head band; and coupling means for rotatably coupling the ear cups to the head band, the ear cups having ear pads on those sides facing each other, respectively, the head band being positioned on that side of each of the ear cups away from the side where the ear pad is provided, said coupling means rotatably coupling the head band to that side of each of the ear cups located away from the side where the ear pad is provided, whereby the coupling means enables each of the ear cups to make vertical and horizontal rotations relative to the ear of the user. This headphone insures free rotation of the ear cups in universal directions, and the rotation angle can be controlled as required. Moreover, the headphone as a whole can be provided in a compact size.