Method of manufacturing glass molding

A method of manufacturing a glass molding using a lower mold and an upper mold, the method comprising:

• preparing an upper mold and a lower mold, wherein said lower mold comprises:
• a recess comprising a bottom portion and a side portion surrounding said bottom portion;
• and
• an outer peripheral planar portion surrounding an upper end of said side portion, wherein a crossing angle between said side portion and said outer peripheral planar portion being set at more than or equal to 45 degrees;
• dropping a molten glass drop onto said lower mold, and
• press molding said molten glass drop dropped onto said lower mold with said lower mold and said upper mold;
• wherein a first part of said molten glass drop fills said recess and a second part of said molten glass drop is located above said outer peripheral planar portion, and wherein a volume of said dropped molten glass drop being such that, when dropped onto said lower mold, a volume of said second part of said molten glass drop is 4.0 times to 6.0 times a volume of said first part of said molten glass drop so that said second part of said molten glass drop is rounded with centripetal force generated by surface tension of said molten glass drop acting on said first part of said molten glass drop, so that a contact of said molten glass with said outer peripheral planar portion is restrained at a time when said molten glass drop is dropped toward said lower mold.

A method of manufacturing a glass molding using an upper mold and a lower mold, the method comprising:

• preparing an upper mold and a lower mold, wherein said lower mold comprises:
• a recess comprising a bottom portion and a side portion surrounding said bottom portion;
• and
• an outer peripheral planar portion surrounding an upper end of said side portion, wherein a crossing angle between said side portion and said outer peripheral planar portion being set at more than or equal to 45 degrees;
• dropping a molten glass drop onto said lower mold, and
• press molding said molten glass drop dropped onto said lower mold with said lower mold and said upper mold;
• wherein a first part of said molten glass drop fills said recess and a second part of said molten glass drop is located above said outer peripheral planar portion, and wherein a volume of said dropped molten glass drop being such that, when dropped onto said lower mold, a volume of said second part of said molten glass drop is 4.0 times to 6.0 times a volume of said first part of said molten glass drop so that said second part of said molten glass drop is rounded with centripetal force generated by surface tension of said molten glass drop acting on said first part of said molten glass drop, so that a gap between molten glass filling said recess and said inner surface of said recess is not present at a time when said molten glass drop is dropped toward said lower mold.