Abstract: A process of core molding is disclosed, which permits increasing the positioning accuracy of a base core and a bonded core relative to each other and also avoids handling the first molded base core outside the die to preclude such trouble as breakage of the common die. By the process, a complete core is obtained, which comprises a base core and a bonded core positioned in and bonded to the base core. The base core is molded in a molding space which is defined by engaging a die element and a common die with each other. After removing the die element from the common die while leaving the molded base core in the common die, a different die element is engaged with the common die to define a different molding space for molding a bonded core. The bonded core is bonded to the base core as it is molded.

Abstract: The cleaning device comprises a dummy disc having at least a hole covering an area in which a control signal is to be recorded, a flexible disc member coaxially arranged on the dummy disc and secured thereto at an inner periphery thereof and a cleaning member attached on one surface of the flexible disc facing to the dummy disc and protruding downwardly through the hole of the dummy disc. The cleaning device is set on a turn table integrally attached to a rotary shaft of the disc player and made in light-pressure contact with an optical pick-up raised so that a lens surface of the pick-up is wiped away thereby during its horizontal movement. In a case where the lens collides with the cleaning member, the cleaning member is pushed up by the lens through the hole of the dummy disc due to the flexibility of the flexible disc, so that a mechanical damage of the lens surface is prevented.