Cooking appliance

A cooking appliance comprising:

• a cooking chamber;
• a movable assembly disposed above the cooking chamber and supporting a heater, the movable assembly being configured to move downward from an original position into the cooking chamber and to return upward to the original position;
• a driver configured to move the movable assembly between the original position and a heating position in the cooking chamber;
• a shielding structure disposed around an opening through which the movable assembly passes, the shielding structure including multiple shielding members arranged such that, when the movable assembly is returned to the original position, the shielding members cooperate to close the opening and suppress microwave leakage from the cooking chamber;
• an original-position detector configured to detect whether the movable assembly has returned to the original position;
• a contact/overload detector configured to detect abnormal contact or overload of the movable assembly during downward movement toward food in the cooking chamber;
• and a controller configured to:
• (i) stop the driver in response to the contact/overload detector detecting the abnormal contact or overload;
• and
• (ii) inhibit microwave heating unless the original-position detector detects that the movable assembly is in the original position with the shielding structure closing the opening.