1. Field of the Invention
The present invention relates to a washing machine, and more particularly to a washing machine that is capable of washing delicate cloths with steam. The present invention also relates to a method of controlling such a washing machine.
2. Description of the Related Art
For a conventional washing machine, a washing process is set on the basis of materials of the laundry. The washing temperature and the number of rinsing times are also set on the basis of materials of the laundry. Water is heated by means of a heater disposed in a water tub of the washing machine so that the heated water is used as wash water.
After a prescribed amount of water is supplied to the conventional washing machine, the washing machine heats water supplied into the washing tub using the heater until the temperature of the water reaches a prescribed washing temperature. As the reverse turn of the washing tub is repeated, a detergent supplied along with the water is dissolved, whereby the washing operation is carried out.
The conventional washing machine requires an installation space of the heater, which is provided at the lower part of the washing tub for heating water. As a result, the size of the conventional washing machine is increased, which requires a corresponding increase in water. Also, a large amount of water is necessary to dissolve the detergent, which leads to further consumption of electric energy and increase of the washing time.
To this end, a washing machine has been developed that is capable of washing the laundry with steam to reduce the amount of water to be used. When hot steam contacts the laundry, however, the laundry may be damaged due to the high temperature of the steam. Furthermore, when the hot steam contacts the surfaces of the poor heat-resistant laundry, such as wool, silk, or delicate clothes, the laundry is easily damaged. When the hot steam contacts the detergent applied to the clothes, on the other hand, the detergent sticks to the clothes. As a result, the washed clothes are stained. Therefore, it is required that the washing process be carried out at a suitable washing temperature when the laundry is to be washed using steam.