| 摘要 |
PURPOSE:To detect a subtle change in the surface temperature of food in a microwave oven having an infrared ray sensor that intermittently heats the food by the intermittent microwave by causing a shutter to close when the food is heated by generating the microwave, and to open when the microwave is not generated to heat the food-stuff. CONSTITUTION:Since the shutter 4 is in a closed position when a magnetron is oscillating, noise due to the magnetron and microwave does not enter into an infrared ray sensor 5, and the S/N ratio of the output Vs of the infrared ray sensor 5. As a result, the food temperature Ts can accurately be detected. Moreover, since the shutter 4 is normally closed when the food temperature is rising, flying objects from the food will not smear the infrared ray sensor element 6 contained in the infrared ray sensor 5 to an extent that the sensing of the surface temperature of the food is not possible. |
