摘要 |
A reflective plate 72 is arranged so as to reflect infrared rays, radiated from a heating wire 71, outside of a heater 70 and may be made of steel. A number of cavities 73 are arranged on the surface of the reflective plate 72. Since the cavities 73 have an aspect ratio of 0.17 to 0.7, the infrared reflectance can be increased compared to a reflector with no cavities.
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