NEAR INFRARED RAY HEATING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a means for heating a metal plate-like object with near infrared rays while suppressing reduction in absorption rate even when the output ratio is reduced as the whole near infrared ray heating device.SOLUTION: A near infrared lamp to be lighted is selected according to heating temperature, and the selected near infrared lamp is lighted by the output ratio not less than 40% according to the heating temperature. For selecting the near infrared lamps to be lighted, a distance in the plate-width direction between the near infrared lamps to be lighted should not exceed 50 mm.