How did the rice cooker develop?

1956 before Christmas, Toshiba tried 700 electric cookers with so-called "timing function". The timing principle is to add water to the outer pot and control the heating time. When the water in the outer pot evaporates, stop heating, and the rice in the inner pot is cooked into rice. Toshiba adopted door-to-door sales, and the promotion of rice cookers was successful. A month later, Toshiba produced 200,000 rice cookers. Four years later, half of Japanese families bought this kind of pot. Nine years later, this timing design was replaced by other timing designs. New rice cookers are generally equipped with a temperature control device at the bottom of the outer pot. Before the temperature of the inner pot reaches 100 degrees Celsius (2 12 degrees Fahrenheit), the heating device will work at full load. The temperature of the inner pot will not exceed 100℃ until the excess water in the pot is absorbed and evaporated by the rice. At this time, the temperature control device will stop the heating device, or turn it to the heat preservation state of about 65 degrees Celsius (150 degrees Fahrenheit). The invention reduces the time and manpower spent by many families on cooking.