| 摘要 |
PURPOSE:To sense a proper scorch and terminate a heating operation by a method wherein a heating device such as an electric oven etc. is provided with a lamp for radiating a visible light to the heated material and a light sensor for receiving reflected light from the heated material. CONSTITUTION:When a knob 21' of a volume of the operating unit 21 in a heating devide is set at a position shown in the drawing, resistance is transformed to a digital signal by a voltage transducer 24; temperature of the hot air is set by the micro computer 28 to send a signal to a power source 16 and to drive the lamp 10, electric heaters 5, 5', motor 8 and fan 9. The light sensor 14 senses a luminous intensity of the reflected light from the heated material and transmits the signal to the micro computer 28. Temperature of the hot air passed through the electric heaters 5, 5' and the fan 9 is sensed by the temperature sensor 20 and controlled to a predetermined temperature through the power source. Since, when the heated material is started to scorch, both a heating temperature and a variation in luminous intensity of the reflected light for each of the heated materials are already stored in the micro computer, so that a luminous intensity of the heated material is decreased and the heating operation is terminated at the desired value. Therefore, it is always possible to heat the material to a proper temperature depending on the king of the heated material. |
