Abstract: A cylindrical magnetic pole portion of a rotor core is constituted by first and second cylindrical magnetic pole sub-portions prepared as solid bodies. First and second magnetic poles are formed on the first and second cylindrical magnetic pole portions so as to be arranged in a circumferential direction so as to be separated from each other on an inner peripheral side by first and second recessed grooves recessed into an inner peripheral surface, and linked to each other on an outer peripheral side by first and second thin layer portions constituted by floor portions of the first and second recessed grooves.

Abstract: A cylindrical magnetic pole portion of a rotor core is constituted by first and second cylindrical magnetic pole sub-portions prepared as solid bodies. First and second magnetic poles are formed on the first and second cylindrical magnetic pole portions so as to be arranged in a circumferential direction so as to be separated from each other on an inner peripheral side by first and second recessed grooves recessed into an inner peripheral surface, and linked to each other on an outer peripheral side by first and second thin layer portions constituted by floor portions of the first and second recessed grooves.

Abstract: A portable electronic device, such as a portable sound reproducing device, a portable sound recording/reproducing device, a portable radio receiver or a portable video tape recorder, comprising a case containing an electronic circuit assembly and having a front panel, a plurality of operating buttons for operating control switches for controlling the electronic circuit assembly, supported on the front panel is provided with a sliding cover assembly slidably provided on the front panel and capable of being shifted between a first position to cover the operating buttons and a second position to expose the operating buttons. The sliding cover assembly is retained at the first position by a retaining mechanism to prevent the accidental operation of the operating buttons.