Abstract: A microwave oven adapted to radiate microwaves of mutually reverse phases to minimize impedance variation of a waveguide in response to load change of foodstuff, thereby maintaining an output of the microwave at a constant level regardless of load amount of the foodstuff and maintaining an electric field distribution in a cavity at a constant level as well.

Abstract: A microwave oven for radiating microwaves generated from a magnetron into a cavity to heat and cook foodstuff disposed therein, the microwave oven comprising an antenna disposed between a magnetron and the cavity for converting the microwaves to circularly polarized waves to radiate same into the cavity, the microwave oven having the advantage in that the foodstuff in the cavity is heated by radiation of the circularly polarized waves, thereby enabling a uniform heating of the foodstuff and improving an absorption efficiency of microwave energy.

Abstract: A waveguide of a microwave oven is provided to keep constant output and electric field distribution at a cavity regardless of food load by minimizing change in impedance of waveguides depending on food load for cooking, the waveguide comprising radiating holes of first and second output waveguides formed at top and bottom parts of a lateral wall of the cavity centering the power supply hole of the input waveguide to spray microwaves having the electric fields of opposite phases, whereby change in impedance of the waveguide depending on the change in food load is minimized to keep the output from the microwave oven and the electric field distribution constant regardless of food load.

Abstract: A microwave oven is disclosed in which the structure of the wave guiding tube is improved such that the variation of the impedance is minimized in spite of the variation of the load of the food, thereby making it possible to maintain the output of the microwave oven at a constant level regardless of the load of the food. The microwaves are divided into a plurality of wave streams, and the wave streams are made to have different phases. The microwave oven includes an input wave guiding tube coupled with a magnetron, for receiving microwaves from the magnetron. A first output wave guiding tube communicates to the input wave guiding tube, for receiving the microwaves from the input wave guiding tube to diffusely irradiate the microwaves into a cavity. A second wave guiding tube communicates to the input wave guiding tube, for converting the microwaves to a phase different from that of the first wave guiding tube to irradiate them into the cavity.

Abstract: A microwave oven includes a cooking chamber in which a turn table is disposed for rotation about a vertical axis, and vertical up/down movement along the axis. The turn table has an axle extending downwardly therefrom along the axis. The lower end of the axle rests on a cam surface of a rotary cam member whereby the cam surface causes the axle (and thus the turn table) to alternately move up and down when the rotary cam member is rotated by a first motor. A second motor is connected to the axle to simultaneously rotate the axle and turn table. A traction member is fixed to the rotary cam and overlies a portion of the axle. The traction member extends along a portion of the cam surface which causes the axle to move downwardly, whereby the traction member can pull the axle downwardly if the axle does not properly gravitate downwardly.

Abstract: A microwave oven includes a heating space in which a motor-driven turn-table is disposed. A drive shaft for the turn-table extends upwardly through the floor. A shielding member is mounted to the underside of the floor and includes a horizontal wall portion having a second hole through which the drive shaft extends. A plurality of reflectors are upstanding from the horizontal wall portion and are circumferentially spaced about the second hole. The reflectors reflect microwaves toward the floor to dampen the microwaves. Slots formed in the horizontal wall portion outside of the reflectors conduct heat to a chamber located below the horizontal wall portion in which a motor is mounted for rotating the drive shaft.