Air blowing method for mold for a disk molding and a mold therefor

A mold for molding a disk, the disk having an inside and an outside, comprising:

• a fixed mold and a movable mold;
• a cavity formed between the fixed mold and the movable mold;
• a mirror plate provided as part of one of either the fixed mold or the movable mold;
• a stamper having an outer circumference disposed on the mirror plate facing the cavity formed between the fixed mold and the movable mold;
• a holding means disposed on the other of either the movable mold or the fixed mold for holding the outer circumference of the stamper;
• a plurality of air passages for blowing air from the inside and the outside of the disk to be formed in the cavity;
• the holding means including:
• the main body;
• a bottom side;
• an outer projection wall provided on the main body abutting the mirror plate;
• an inside projection wall spaced from the surface of the stamper so as to form a gap for blowing out air;
• a recessed portion formed between the outer projection wall and the inside projection wall;
• a seat portion opened toward the bottom side and accommodating a resilient means for biasing the holding means to the mirror plate through a biasing force;
• and
• a stopper means for determining a projection amount of the holding means while engaging with the main body in such a manner that the holding means has a stroke-length corresponding to the distance by the holding means by being pushed by the resilient means against the stopper means;
• the plurality of the air passages including:
• at least one of communication passages which comes through between the recessed portion of the holding means and the bottom side of the holding means and another of communication passages of which is formed on the mirror plate and between the outer circumference of the stamper and the outer projection wall of the holdings means.