Strengthened glass manufacturing apparatus and strengthened glass manufacturing method using the same

A strengthened glass manufacturing apparatus comprising:

• a strengthening chamber comprising a first chamber having a first space;
• a preheating chamber comprising a second chamber having a second space, the second space being different from the first space;
• a first induction coil in the preheating chamber, the first induction coil in a shape of a horizontal plane spirally wound pancake coil defined by a horizontal plane parallel to a horizontal direction, the horizontal plane spirally wound pancake coil being above the second space, and the first induction coil in the shape of the horizontal plane spirally wound pancake coil being buried within an upper portion of the preheating chamber and surrounding a hole in the upper portion of the preheating chamber;
• a guide part extending in the horizontal direction from the strengthening chamber, and
• a cassette transfer part to move a cassette from the preheating chamber to the strengthening chamber, the cassette transfer part being arranged to pass a cable through the hole in the upper portion of the preheating chamber,
• wherein the preheating chamber is configured to move along the guide part from a first position where the preheating chamber does not overlap the strengthening chamber to a second position where the preheating chamber overlaps the strengthening chamber, and
• wherein the first induction coil is not horizontally coplanar with the second space and does not surround sidewalls of the preheating chamber.