Dishwasher and control method thereof

Abstract

Disclosed a control method of a dishwasher comprising a main-washing cycle for washing one or more washing objects which are held in a tub; a rinsing cycle for rinsing the washing objects washed in the main-washing cycle by injecting wash water; a normal drying cycle for drying the washing objects rinsed in the rinsing cycle, wherein the main-washing cycle comprises a pre-steam water supply step for supplying steam water to a sump so as to supply steam to the tub; a pre-steam supply step for generating steam by heating a heater and supplying the steam to the tub; a main-wash water supply step for supplying wash water for washing to the sump, without draining the steam water supplied to the sump; a main-washing step for washing the washing objects by circulating the supplied wash water; and a main-wash water drainage step for draining the wash water.

What is claimed is: 
     
         1 . A control method of a dishwasher, comprising:
 washing one or more objects which are held in a tub in a main-washing cycle;   rinsing the objects washed in the main-washing cycle in a rinsing cycle by injecting wash water;   drying the objects rinsed in the rinsing cycle in a normal drying cycle,   wherein the main-washing cycle comprises:   supplying steam water to a sump in a pre-steam water supply step;   generating steam in a pre-steam supply step by heating a heater and supplying the steam to the tub;   supplying wash water in a main-wash water supply step to the sump, without draining the steam water supplied to the sump;   washing the objects in a main-washing step by circulating the supplied wash water; and   draining the wash water in a main-wash water drainage step.   
     
     
         2 . The control method of  claim 1 , wherein the amount of the steam water supplied in the pre-steam water supply step is less than the amount of the wash water supplied in the main-wash water supply step. 
     
     
         3 . The control method of  claim 1 , wherein the dishwasher comprises:
 a pump supplying the wash water stored in the sump to an injection arm;   a pump heater provided in the pump for heating the wash water; and   a steam outlet hole provided in the pump for exhausting steam, and   wherein a water level of the steam water supplied in the pre-steam water supply step is lower than the steam outlet hole.   
     
     
         4 . The control method of  claim 3 , wherein a water level of the wash water supplied in the main-wash water supply step is higher than the steam outlet hole. 
     
     
         5 . The control method of  claim 1 , wherein the pre-steam supply step comprises:
 supplying steam in a first steam step from a front side of the tub by using a first steam nozzle.   
     
     
         6 . The control method of  claim 5 , wherein the pre-steam supply step comprises:
 supplying steam in a third steam step by using one or more injection arms provided in the tub.   
     
     
         7 . The control method of  claim 1 , wherein the main-washing cycle injects the wash water mixed with dishwashing liquid toward the objects, and
 wherein the control method further comprises a pre-washing cycle for injecting the wash water mixed with no dishwashing liquid to the objects,   wherein the pre-washing cycle is before the main-washing cycle.   
     
     
         8 . The control method of  claim 1 , further comprising a steam drying cycle after the rinsing cycle, the steam drying cycle comprising:
 supplying drying steam water in a drying steam water supply step; and   supplying steam to the tub in a drying steam supply step.   
     
     
         9 . The control method of  claim 1 , wherein the steam water supply step of the pre-steam water supply step comprises:
 supplying wash water to the pump in a first water supply step to wash the sump and the pump; and   draining the supplied wash water in a first drainage step.   
     
     
         10 . The control method of  claim 9 , further comprising:
 circulating wash water inside the sump and the pump in a first circulating step by driving the pump and washing internal spaces of the sump and pump,   wherein the first circulating step is before the first drainage step.   
     
     
         11 . The control method of  claim 9 , further comprising:
 supplying steam water for generating steam in a second water supply step to the sump,   wherein the second water supply step is after the first drainage step, and   wherein the first drainage step drains all of the wash water supplied in the first water supply step.   
     
     
         12 . The control method of  claim 9 , wherein the first drainage step drains a predetermined amount of the wash water supplied in the first water supply step and generates steam by using the remaining wash water. 
     
     
         13 . The control method of  claim 1 , further comprising:
 selecting a course or an option in a course/option selecting step for adding steam to the selected course,   wherein the course/option selecting step is before the main-washing cycle.   
     
     
         14 . The control method of  claim 13 , wherein steam is supplied by selecting an option for steam in the course/option selecting step, even when a non-steam course is selected. 
     
     
         15 . The control method of  claim 13 , wherein when a steam course is selected in the course/option selecting step, the steam course is implemented and comprises a main washing cycle, a rinsing cycle, a steam drying cycle, and a normal drying cycle which supply steam. 
     
     
         16 . The control method of  claim 13 , wherein when a steam drying course is selected, the steam drying course is implemented and comprises a main-washing cycle, a rinsing cycle, a steam drying cycle, and a normal drying cycle. 
     
     
         17 . The control method of  claim 8 , wherein the steam water supply step of the drying steam water supply step comprises:
 supplying wash water to the pump in a first water supply step to wash the sump and the pump; and   draining the supplied wash water in a first drainage step.   
     
     
         18 . The control method of  claim 17 , further comprising:
 circulating wash water inside the sump and the pump in a first circulating step by driving the pump and washing internal spaces of the sump and pump,   wherein the first circulating step is before the first drainage step.   
     
     
         19 . The control method of  claim 17 , further comprising:
 supplying steam water for generating steam in a second water supply step to the sump,   wherein the second water supply step is after the first drainage step, and   wherein the first drainage step drains all of the wash water supplied in the first water supply step.   
     
     
         20 . The control method of  claim 17 , wherein the first drainage step drains a predetermined amount of the wash water supplied in the first water supply step and generates steam by using the remaining wash water.