Abstract: In a backlight unit provided with a plurality of optical sheets, a first optical sheet is characterized by having different coefficients of linear expansion in two different directions (a first direction and a second direction) with the coefficient of linear expansion in the first direction larger than that in the second direction. A second optical sheet is arranged adjacently to the first optical sheet. The coefficient of linear expansion of the second optical sheet in approximately the same direction as the first direction of the first optical sheet is approximated to the coefficient of linear expansion of the first optical sheet in the first direction.

Abstract: A microwave oven determines an appropriate time to stop heating even if multiple food items are placed in the heating chamber. After any position on the bottom surface of the microwave oven reaches 75 deg C., a search is made for any other position having a temperature of at least 70 deg C. If such a position is detected, heating is concentrated on that position until it reaches 75 deg C. When all food-containing positions in the microwave oven have reached a temperature of at least 75 deg C., the heating operation performed by the magnetron is stopped.

Abstract: A microwave oven heats all food in an appropriate manner even if food items are simultaneously placed at multiple locations in a heating chamber. An auxiliary antenna is periodically stopped at an orientation corresponding to a position where a lowest temperature was detected at the start of the heating operation. Between stopped periods, the auxiliary antenna is rotated for a period to apply heat evenly to all food in the oven. If multiple low-temperature points are detected, the central position of these multiple low-temperature points is used for applying concentrated heat.

Abstract: A microwave oven heats all food in an appropriate manner even if food items are simultaneously placed at multiple locations in a heating chamber. An auxiliary antenna is periodically stopped at an orientation corresponding to a position where a lowest temperature was detected at the start of the heating operation. Between stopped periods, the auxiliary antenna is rotated for a period to apply heat evenly to all food in the oven. If multiple low-temperature points are detected, the central position of these multiple low-temperature points is used for applying concentrated heat.

Abstract: A microwave oven determines an appropriate time to stop heating even if multiple food items are placed in the heating chamber. After any position on the bottom surface of the microwave oven reaches 75 deg C., a search is made for any other position having a temperature of at least 70 deg C. If such a position is detected, heating is concentrated on that position until it reaches 75 deg C. When all food-containing positions in the microwave oven have reached a temperature of at least 75 deg C., the heating operation performed by the magnetron is stopped.

Abstract: In a cooking appliance, the foodstuff is placed on a turntable in a heating chamber. Infrared radiation emitted from the foodstuff is sensed by an infrared sense unit. The cooking appliance obtains the number of extrema of the amount of infrared radiation sensed over the period of one cycle of the turntable. The number of foodstuffs is determined according to the number of maxima. A control unit drives a heat unit according to the determined number of foodstuffs.

Abstract: After the initial temperature T0 of a heating chamber is sensed (S34), heating by microwaves is conducted until the sensor output of a humidity sensor exhibits a prescribed humidity change amount of 1.0 V (S35-S39). Then, an additional time period is operated based on initial temperature T0 and a time period passed for the elevation of 1.0 V (S40-S42, S50). Heating by microwaves is conducted for the additional time period (S43, S51), and then heating by a heater is conducted. As a result, the moisture included in the food is evaporated and finished crisp. In other words frozen precooked food may be thawed and cooked into a tasty state.