Microwave oven

摘要

A high frequency heating apparatus is provided with a hood so constructed as to limit infrared ray energy reaching an infrared ray detecting element for detecting infrared rays radiated from an object to be heated within a heating chamber. In heating apparatus, the influence by the reflection of infrared rays is minimized by making the absorption factor approach to about "1" with blackening the inner surface of the hood. Also, the rotation of a chopper to detect infrared rays radiated from the object through chopping operation is detected by a mechanical switch. The output signal from the infrared ray detecting element is synchronous-rectified in synchronism with the switching operation of the mechanical switch.