Washing Machine and Control Method Thereof

Abstract

A washing machine includes a cabinet; an outer basket in the cabinet and configured to contain wash water; an inner basket in the outer basket and configured to accommodate laundry; a water supply valve unit in the cabinet and connected to an external water supply source to receive wash water; a cabinet cover on an upper side of the cabinet and having an input hole for the laundry; and a micro-bubble generator configured to receive wash water from the water supply valve unit, generate micro-bubbles, and supply the micro-bubbles to a washing space. The micro-bubble generator includes a nozzle unit at or near the input hole and configured to generate micro-bubbles by receive wash water in which gas is dissolved or mixed and discharge wash water having the micro-bubbles therein into the inner basket after the micro-bubbles are generated.

What is claimed is: 
     
         1 . A washing machine comprising:
 a cabinet;   an outer basket in the cabinet and configured to contain wash water;   an inner basket in the outer basket and configured to accommodate laundry;   a water supply valve unit in the cabinet and connected to an external water supply source to receive wash water;   a main drain valve at a lower portion of the outer basket, configured to control draining the wash water in the outer basket;   a main drain hose connected to the main drain valve to transport the wash water;   a micro-bubble generator configured to receive the wash water from the water supply valve unit, generate micro-bubbles, and supply the wash water including the micro-bubbles to a washing space, the micro-bubble generator including a drain unit configured to discharge the wash water in a dissolving space; and   a control unit configured to control the drain unit to discharge the wash water in the dissolving space when the main drain valve drains the wash water in the outer basket.   
     
     
         2 . The washing machine according to  claim 1 , wherein the drain unit comprises an electronic valve, and the wash water from the drain unit is discharged through the main drain hose. 
     
     
         3 . The washing machine according to  claim 1 , wherein the micro-bubble generator further includes:
 a dissolving unit configured to dissolve or mix gas in the wash water from the water supply valve unit; and   a nozzle unit configured to receive the wash water in which the gas is dissolved or mixed from the dissolving unit and generate the micro-bubbles.   
     
     
         4 . The washing machine according to  claim 3 , wherein the control unit is configured to close the main drain valve and the drain unit so that drainage is not performed through the main drain hose when the wash water is supplied from the water supply valve unit to the dissolving unit and the inner basket. 
     
     
         5 . The washing machine according to  claim 1 , wherein the washing space is inside the outer basket, and the drain unit is configured to discharge the wash water after completing a supply of the wash water including the micro-bubbles. 
     
     
         6 . A washing machine comprising:
 a cabinet;   an outer basket in the cabinet and configured to contain wash water;   an inner basket in the outer basket and configured to accommodate laundry;   a water supply valve unit in the cabinet and connected to an external water supply source to receive wash water;   a main drain hose connected to the outer basket to transport wash water;   a main drain pump unit connected to the main drain hose and configured to forcibly drain wash water in the outer basket;   a micro-bubble generator configured to receive wash water from the water supply valve unit, generate micro-bubbles, and supply the wash water including the micro-bubbles to a washing space, the micro-bubble generator including a drain unit configured to discharge the wash water remaining in a dissolving space; and   a control unit configured to control the drain unit to discharge the wash water in the dissolving space when the main drain pump unit drains the wash water in the outer basket.   
     
     
         7 . The washing machine according to  claim 6 , wherein the main drain pump unit includes:
 a housing connected to the main drain hose and having a pressurizing space configured to pressurize the wash water;   a drain portion configured to drain pressurized wash water in the housing;   a driving portion connected to the housing and configured to pressurize the wash water; and   a drain line connected to the housing and configured to discharge (i) the wash water from the drain unit, and (ii) air bubbles generated when the wash water is pressurized in the housing toward the micro-bubble generator.   
     
     
         8 . The washing machine according to  claim 6 , wherein the control unit is configured to open a flow path so that the micro-bubble generator and the main drain pump unit communicate with each other when the main drain pump unit is driven. 
     
     
         9 . The washing machine according to  claim 8 , wherein the control unit is configured to control the main drain pump unit and the drain unit so that drainage is not performed through the main drain pump unit and the drain unit when the water supply valve unit supplies wash water to the dissolving space and the inner basket. 
     
     
         10 . The washing machine according to  claim 6 , wherein the micro-bubble generator further includes:
 a dissolving unit configured to dissolve or mix gas in the wash water supplied from the water supply valve unit; and   a nozzle unit configured to receive the wash water in which the gas is dissolved or mixed from the dissolving unit and generate the micro-bubbles,   wherein the control unit closes a drain flow path when the wash water is supplied from the water supply valve unit to the dissolving unit.   
     
     
         11 . The washing machine according to  claim 10 , wherein when the main drain pump unit is driven, the drain unit provides air bubbles in the main drain pump unit to the dissolving unit, and
 the air bubbles provided to the dissolving unit are discharged through the nozzle unit.   
     
     
         12 . The washing machine according to  claim 6 , wherein the washing space is inside the outer basket, and the drain unit is configured to discharge the wash water after completing a supply of the wash water including the micro-bubbles. 
     
     
         13 . A method of controlling a washing machine that includes a micro-bubble generator configured to dissolve or mix gas in wash water, generate micro-bubbles, and supply the wash water including the micro-bubbles to a washing space, the method comprising:
 supplying wash water to a dissolving unit of the micro-bubble generator from a water supply valve unit, closing a main drain hose for draining the wash water in an outer basket of the washing machine using a main drain control device, and closing a drain line of the micro-bubble generator; then   after supplying the wash water to the micro-bubble generator, opening the main drain hose to drain the wash water from the outer basket using the main drain control device, opening the drain line to drain the wash water remaining in the dissolving unit.   
     
     
         14 . The method according to  claim 13 , wherein the main drain control device is at a lower portion of the outer basket. 
     
     
         15 . The method according to  claim 13 , wherein the main drain control device comprises a main drain pump unit that is connected to the main drain hose and that forcibly drains wash water in the outer basket. 
     
     
         16 . The method according to  claim 15 , wherein the drain line is connected to a housing having a pressurizing space configured to pressurize the wash water in the main drain pump unit, and the method further comprises:
 providing air bubbles generated in the housing to the dissolving unit along the drain line, and   discharging the air bubbles provided to the dissolving unit through a nozzle unit of the micro-bubble generator.