Patent Publication Number: US-8540822-B2

Title: Control method of a dishwasher

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     The present application claims priority under 35 U.S.C. §119 and 35 U.S.C. §365 to Korean Patent Application No. 10-2009-0118343, filed in Korea on Dec. 2, 2009, which is hereby incorporated by reference in its entirety. 
     BACKGROUND 
     1. Field 
     A control method of a dishwasher is disclosed to clean a filter. 
     2. Background 
     Generally, a dishwasher washes dishes by directing washing fluid onto dishes positioned therein. In detail, clean washing water received in a sump is directed onto dishes positioned in the washer by a washing fluid injecting unit, and is then returned to the sump and re-supplied to the washing fluid injecting unit via a filter apparatus in the sump. At the end of the wash cycle, the used washing fluid, together with foreign materials held in the filter apparatus, are drained to the outside of the dishwasher. 
     Foreign materials accumulated in the filter apparatus during operation may generate flow resistance, thus reducing flow rate of the washing fluid passing through the filter apparatus. This reduced flow rate may impact the washing performance of the dishwasher and overload the washing pump. In addition, foreign materials adhered to the filter are may not be easily removed, which may cause a pungent odor inside the washer due to decay of the foreign materials. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The embodiments will be described in detail with reference to the following drawings in which like reference numerals refer to like elements wherein: 
         FIG. 1  is a cross-sectional view of a dishwasher according to an embodiment as broadly described herein; 
         FIG. 2  is a bottom view of a sump of the dishwasher shown in  FIG. 1 ; 
         FIG. 3  is a cross-sectional view taken along line I-I′ of  FIG. 2 ; 
         FIG. 4  is a cross-sectional view taken along line II′-II′ of  FIG. 2 ; 
         FIG. 5  illustrates operation of washing fluid in the dishwasher shown in  FIG. 1 ; 
         FIGS. 6 and 7  are cross-sectional views of the sump shown in  FIGS. 2 and 3 , illustrating the operation of washing fluid in the dishwasher shown in  FIG. 1 ; 
         FIG. 8  is a flowchart of a control method of a dishwasher according to an embodiment as broadly described herein; 
         FIG. 9  is a flowchart of a control method of a dishwasher according to another embodiment as broadly described herein; 
         FIG. 10  is a flowchart of a control method of a dishwasher according to another embodiment as broadly described herein; 
         FIG. 11  is a cross-sectional view of a filter housing of a dishwasher according to an embodiment as broadly described herein; and 
         FIG. 12  is a cross-sectional view of a filter housing of a dishwasher according to another embodiment as broadly described herein. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a dishwasher  1  according to a first embodiment as broadly described herein may include a case  10 , a tub  11  received inside the case  10 , a door  12  provided on a front surface of the tub  11  to open and close the washer, and a sump  20  provided at a lower side of the tub  11  to store washing fluid. 
     A lower rack  14  and an upper rack  13  are provided inside the tub  11  to receive wash items therein. The upper rack  13  is disposed above the lower rack  14  spaced apart by a predetermined distance. The upper rack  13  and the lower rack  14  may be guided by a guide rail (not shown) provided at an inner side of the tub  11 , such that they may be drawn in and out through the front of the tub  11 . A lower nozzle  17 , an upper nozzle  16 , and a top nozzle  15  may direct washing fluid from the sump  20  into the inside of the tub  11 . 
     The lower nozzle  17  may be connected to an upper side of the sump  20  to direct washing fluid to the lower portion of the tub  11 , onto wash items that are mounted on the lower rack  14 . A lower nozzle connecting part  62  may connect the sump  20  to the lower nozzle  17 . The upper nozzle  16  may be positioned at a central portion of the washer to direct washing fluid toward the upper rack  13 , and the top nozzle  15  may be disposed at a ceiling portion of the tub  11  to direct washing fluid downward. 
     A washing fluid guide  40  may guide washing fluid toward the upper rack  13  through the top nozzle  15  or the upper nozzle  16 . A guide connecting part  64  may connect the sump  20  to the washing fluid guide  40 . 
       FIG. 2  is a bottom view of the sump  20 ,  FIG. 3  is a cross-sectional view taken along line I-I′ of  FIG. 2 , and  FIG. 4  is a cross-sectional view taken along line II-II′ of  FIG. 2 . The sump  20  may include a filter device  50  that filters foreign materials from the washing fluid, a washing pump  70  that pumps the washing fluid filtered by the filter device  50 , and a channel opening and closing device  80  that opens and closes a channel so as to direct washing fluid to the lower nozzle  17  or the washing fluid guide  40 . 
     The filter device  50  may include a first filter  52  that filters relatively large foreign materials from the washing fluid, a second filter  54  that is provided on the outer side of the first filter  52  and filters relatively fine foreign materials from the washing fluid, and a filter housing  51  in which the first filter  52  and the second filter  54  are received. A filter inlet  51   a  may be provided at an upper portion of the filter housing  51  so as to supply washing fluid to the filter device  50 . The foreign materials are then filtered from the washing fluid as it passes through the first filter  52  and the second filter  54 . 
     A pump inlet  58  is positioned at side of the lower portion of the filter housing  51  to supply filtered washing fluid to the washing pump  70 . The washing fluid stored in the sump  20  may flow to the pump inlet  58  through the filter device  50  due to the suction force of the washing pump  70 . 
     The washing pump  70  includes a motor  71  that provides a driving force and an impeller  72  that rotates in response to the driving force of the motor  71 . A pump discharging device  78  discharges washing fluid from the pump  70 . Washing fluid is supplied to the impeller  72  through the pump inlet  58  and is discharged through the pump discharging device  78  via the impeller  72 . A heater  68  may heat the washing fluid so as to wash dishes with washing fluid heated to a relatively high temperature, thereby improving washing efficiency. 
     The pump discharging device  78  is connected to the channel opening and closing device  80 . The channel opening and closing device  80  may include an opening and closing valve  82  and an opening and closing driver  81  that drives the opening and closing valve  82 . Washing fluid supplied to the channel opening and closing device  80  may flow to the lower nozzle connecting part  62  or the guide connecting part  64  through the opening and closing valve  82 . In other words, the opening and closing valve  82  directs washing fluid to the lower nozzle  17  via the lower nozzle connecting part  62 , and directs washing fluid to the upper nozzle  16  or the top nozzle  15  via the guide connecting part  64 . 
     The washing fluid guide  40  may include separate channels that communicate with the top nozzle  15  or the upper nozzle  16 , respectively. For example, the washing fluid guide  40  may include a top nozzle channel and an upper nozzle channel so that washing fluid may be directed to the top nozzle channel or the upper nozzle channel by the opening and closing valve  82 . The top nozzle  15 , the upper nozzle  16 , and the lower nozzle  17  may be selectively opened such that washing may flow through only some of the nozzles  15 ,  16 , and/or  17 . Alternatively, all the nozzles  15 ,  16 , and  17  may be opened so that washing fluid flows through all the nozzles  15 ,  16 , and  17 . 
     A draining pump  90  may generate a suction force to drain the washing fluid and a draining device  59  provided between the filter device  50  and the draining pump  90  may drain the washing fluid and the foreign materials. When the draining pump  90  is driven, the washing fluid stored in the sump  20  may be discharged to the outside through the draining device  50  and the draining pump  90  together with the foreign materials captured in the filter device  50 . 
     Washing fluid, such as, for example, clean water, may be supplied from an external source and stored in the sump  20 . When the washing pump  70  is driven, the washing fluid may be simultaneously or selectively directed to the top nozzle  15 , the upper nozzle  16 , and the lower nozzle  17  through the washing pump  70  and the channel opening and closing device  80 . The washing fluid may be mixed with a wash agent in the tub  11  to wash the items received in the racks  13  and  14 , and may then be stored in the sump  20  again. The foreign materials may be filtered from the washing fluid by the suction force of the washing pump  70  while the washing fluid passes through the filter device  50 . Thereafter, the cleaned/filtered washing fluid may be again directed into the tub  11  through the washing pump  70  and the channel opening and closing device  80 . The washing process may be repeated several times. 
       FIG. 5  is a cross-sectional view of the dishwasher shown in  FIG. 1 , illustrating a flow of washing fluid, and  FIGS. 6 and 7  are cross-sectional views of the sump  20 , illustrating the flow of washing fluid. 
     When the washing pump  70  is driven, the washing fluid flows from the sump  20  to the washing fluid guide  40 . The washing pump  70  may be turned-off when the washing fluid reaches a predetermined height within the washing fluid guide  40 . After the washing pump  70  is turned off, the washing fluid in the washing fluid guide  40  falls downward due to its own potential energy (i.e., its own weight, or gravity) and may be therefore re-supplied to the sump  20 . The washing fluid back flows through the channel opening and closing device  80  and the washing pump  70  and may be thus supplied to the filter device  50 . 
     In this process, the washing fluid collides with the filter device  50  as it back flows, at a magnitude of force corresponding to the potential energy of the washing fluid, such that the foreign materials are separated from the filter device  50 , in particular, the first and second filters  52  and  54 . In other words, the foreign materials accumulated in the filters  52  and  54  may be separated from the surface of the filters  52  and  54  by the collision force of the washing fluid with the filter device  50 . 
     More specifically, the foreign materials attached to the surface of the first and second filters  52  and  54  by the suction force of the washing pump  70  may be separated from the first and second filters  52  and  54  by the collision force of the washing fluid. Hereinafter, the process of cleaning the filter using the back flow force of the washing fluid will be referred to as a “cleaning cycle”. 
     In detail, a height from the bottom surface of the dishwasher  1  to the lower nozzle  17  may be defined as hl, a height from the bottom surface of the dishwasher  1  to the top nozzle  15  may be defined as ht, and a height of the washing fluid rising through washing fluid guide  40  may be h 1 . Herein, the magnitude of h 1  may be greater than hl and less than ht. When h 1  is less than hl, the height of the washing fluid is too low, and the potential energy of the washing fluid is relatively small. As a result, the collision force of the washing fluid which may be applied to the filter device  50  is insignificant. 
     Therefore, the driving force of the washing pump  70  may control the washing fluid so that the washing fluid rises to the level h 1  in the washing fluid guide. 
     In addition, the pump inlet  58  may be inclined, or tilted upward toward the filter device  50  from the washing pump  70 . As shown in  FIG. 4 , the pump inlet  58  may be tilted upward at an angle α from the bottom surface of the sump  20 . In this case, the washing fluid flowing to the filter device  50  through the pump inlet  58  impinges on central portions, in a height direction, of the first filter  52  and the second filter  54 , such that the foreign materials may be easily separated from the filters  52  and  54 . 
       FIG. 8  is a flowchart of a control method of a dishwasher as embodied and broadly described herein. 
     The dishwasher  1  may perform a pre-washing cycle followed by a main washing cycle. The pre-washing cycle, which includes removing foreign materials from the wash items with the washing fluid at room temperature (without heating) may include fluid supply, washing, and draining cycles (S 11 ). 
     The main washing cycle may be performed after the pre-washing cycle. In the main washing cycle, washing fluid, such as, for example, clean water, may be supplied from an external source and mixed with detergent in a detergent box, and may then be in turn supplied to the sump  20  (S 12  and S 13 ). 
     When the washing pump  70  is driven (S 14 ), the washing fluid may be directed from the sump  20  to the washing fluid guide  40 , and an elapsed time after the driving of the washing pump  70  is initiated may be counted. If the driving time of the washing pump  70  exceeds a predetermined first set time (S 15 ), which may correspond to a time required to perform a main washing cycle, the draining pump  90  may be driven (S 16 ). When the draining pump  90  is driven, the washing fluid and the foreign materials stored in the sump  20  may be discharged to the outside through the draining device  59 . Therefore, as the draining pump  90  is driven, the level of the washing fluid stored in the sump  20  may be lowered. 
     The elapsed time after the driving of the draining pump  90  is initiated may be counted. It is determined whether the driving time of the draining pump  90  exceeds a predetermined second set time (S 17 ). The second set time may correspond to a particular degree to which the level of the washing fluid stored in the sump  20  is lowered, according to the performance of the draining cycle. Foreign materials separated from the filter device  50  may float to the upper surface of the sump  20  when a cleaning cycle is performed if the level of the washing fluid stored in the sump  20  is too high. 
     When the driving time of the draining pump  90  exceeds the second set time, the cleaning cycle may be performed. The cleaning cycle may include switching the opening and closing valve  82  so that the washing fluid can flow to the upper nozzle  16  or the top nozzle  15  (S 18 ). In other words, the washing fluid channel may be switched so that the washing fluid rises to a higher position than the lower nozzle  17  and may flow to the upper nozzle  16  or the top nozzle  15  through the guide connecting part  64 . At this point, the washing pump  70  may be turned-off (S 19 ). 
     When the washing pump  70  is turned off, the washing fluid rising along the washing water guide  40  due to the pumping force of the washing pump  70  falls downward due to its own weight and is supplied into the sump  20 . The washing fluid supplied into the sump  20  flows to the filter device  50  through the washing pump  70  and strongly collides with the first and second filters  52  and  54  such that the foreign materials attached to the first and second filters  52  and  54  may be separated from the first and second filters  52  and  54 . The separated foreign materials are directed to the draining device  59  by the suction force of the draining pump  90  together with the washing fluid so as to be discharged to the outside. 
     When performing the cleaning cycle, it is determined whether an elapsed time after turning off the washing pump  70  exceeds a predetermined third set time (S 20 ). The third set time may be defined as an amount of time corresponding to a point at which the washing fluid collides with the filter device  50  after turning off the washing pump  70 . 
     When the elapsed time after turning off the washing pump  70  exceeds the third set time, the washing pump  70  may be driven at a predetermined set rotating speed (S 21 ). The set rotating speed may correspond to a driving force that that is capable of raising the washing fluid to a height of h 1  in the washing fluid guide  40 . The washing pump  70  is turned-off (S 22 ) and the draining pump  90  is turned off (S 23 ) after the washing pump  70  is driven at the set rotating speed. 
     As described above, driving the washing pump  70  at the set rotating speed (S 21 ) and then turning the washing pump  70  off (S 22 ) causes the cleaning cycle to be performed again, such that the washing fluid back flows from the washing fluid guide  40  to the washing pump  70  and is supplied to the filter device  50 . In this process, the foreign materials are separated from the first and second filters  52  and  54  and discharged to the draining unit  59  together with the washing fluid. When the discharge of the foreign materials is complete, the draining pump  90  is turned off (S 23 ). 
     As described above, the washing pump  70  is first driven at the set rotating speed and then turned off so that the level of the washing fluid is lowered by a predetermined height so that the cleaning mode may be performed and the foreign materials separated from the filter device  50  may be easily discharged. 
     In the embodiment shown in  FIG. 8 , the cleaning cycle is performed twice. However, in alternative embodiments, the cleaning cycle may be performed three times or more based on an operating time of the draining pump  90 . For example, in the embodiment shown in  FIG. 8 , the cleaning cycle is performed in the main washing cycle. However, the cleaning cycle may be performed in the pre-washing cycle. 
     In a control method of a dishwasher according to the embodiment shown in  FIG. 9 , the dishwasher  1  may perform a pre-washing cycle (S 31 ) followed by a main washing cycle (S 32 ). In the main washing cycle, the washing pump  70  is driven (S 34 ) after washing fluid is supplied (S 33 ) such that the washing fluid may be injected into the tub  11 . It is determined whether the driving time of the washing pump  70  exceeds a fourth set time (S 35 ). The fourth set time may be defined as a time at which foreign materials are accumulated in the filter device  50  to a certain degree while performing the washing cycle. When the driving time of the washing pump  70  exceeds the fourth set time, the cleaning cycle is performed. 
     Performing the cleaning cycle includes switching the opening and closing valve  82  so that the washing fluid may flow to the upper nozzle  16  or the top nozzle  15  (S 36 ). In other words, the washing fluid channel may be switched so that the washing fluid may rise to a higher position than the lower nozzle  17  and may flow to the upper nozzle  16  or the top nozzle  15  through the guide connecting part  64 . The washing pump  70  may then be turned-off (S 37 ). 
     When the washing pump  70  is turned off, the washing fluid rising along the washing fluid guide  40  due to the pumping force of the washing pump  70  falls downward due to its own weight and is supplied into the sump  20 . The washing fluid supplied into the sump  20  flows to the filter device  50  through the washing pump  70  and strongly collides with the first and second filters  52  and  54  such that the foreign materials attached to the first and second filters  52  and  54  may be separated from the first and second filters  52  and  54 . This prevents foreign materials from sticking or adhering to the surface of the filter during the washing cycle. 
     When performing the cleaning cycle, it is determined whether an elapsed time after turning off of the washing pump  70  exceeds a predetermined fifth set time (S 38 ). The fifth set time may be defined as a point in time at which, after turning off the washing pump  70 , the washing fluid collides with the filter device  50 . 
     When the elapsed time after turning off the washing pump  70  exceeds the fifth set time, the washing pump  70  is driven at a predetermined set rotating speed (S 39 ). The set rotating speed may correspond to a driving force that is capable of raising the washing fluid to a height of h 1  in the washing fluid guide  40 . The washing pump  70  may be turned-off (S 40 ) after being driven at the set rotating speed to perform the cleaning cycle again. This causes the washing fluid to back flow through the washing fluid guide  40  to the washing pump  70 , and to collide with the filters  52  and  54  again. In this process, the foreign materials adhered to the first and second filters  52  and  54  may be separated from the first and second filters  52  and  54 . 
     When the cleaning cycle is completed, the draining pump  90  is driven (S 41 ) so that washing fluid may be discharged to the outside through the draining device  59  together with the foreign materials separated from the first and second filters  52  and  54 . When the draining cycle is completed, the draining pump  90  is turned-off (S 42 ), and the main washing cycle is completed. 
       FIG. 10  is a flowchart of a control method of a dishwasher according to another embodiment as broadly described herein. Steps S 51  to S 54  shown in  FIG. 10  are essentially the same as steps S 31  to S 34  shown in  FIG. 9  and therefore, a detailed description thereof will be omitted. 
     After the washing pump  70  is driven (S 54 ), it is determined whether the driving time of the washing pump  70  exceeds a sixth set time (S 55 ). The sixth set time may be defined as a point at which the foreign materials are accumulated to a certain degree in the filter device  50  during the washing cycle. 
     When the driving time of the washing pump  70  exceeds the sixth set time, the opening and closing valve  82  is switched (S 56 ) so that the washing pump  70  may be switched to a cleaning mode, that is, a mode that supplies washing fluid to the upper nozzle  16  or the top nozzle  15 . When the opening and closing valve  82  is switched to the upper or top nozzle mode, the washing fluid rises along the washing fluid guide  40  so that the washing fluid rises to a higher position than the lower nozzle  17 . The washing pump  70  may then be turned-off (S 57 ). 
     The washing fluid rising along the washing fluid guide  40  due to the pumping force of the washing pump  70  falls downward due to its own weight and is supplied into the sump  20 . The washing fluid supplied into the sump  20  flows to the filter device  50  through the washing pump  70  and strongly collides with the first and second filters  52  and  54  such that the foreign materials attached to the first and second filters  52  and  54  may be separated from the first and second filters  52  and  54 . 
     After the washing pump  70  is turned-off to perform the cleaning of the first and second filters  52  and  54 , the washing pump  70  is then re-started (S 58 ) so that washing fluid may be injected from the sump  20  into the tub  11 . 
     The draining pump  90  is then driven (S 59 ). When the draining pump  90  is driven, the washing fluid and the foreign materials stored in the sump  20  may be discharged to the outside through the draining device  59 . 
     An elapsed time after the driving of the draining pump  90  may be counted. It is determined whether the driving time of the draining pump  90  exceeds a predetermined seventh set time (S 60 ). The seventh set time may correspond to a degree to which a level of the washing fluid stored in the sump  20  is lowered, according to the performance of the draining cycle. 
     When the driving time of the washing pump  90  exceeds the seventh set time, the opening and closing valve  82  may be switched (S 61 ) so that the washing fluid may flow to the upper nozzle  16  or the top nozzle  15 . The washing pump  70  may then be turned-off (S 62 ). At this time, the washing fluid rising along the washing fluid guide  40  due to the pumping force of the washing pump  70  falls downward due to its own weight such that the washing fluid may be supplied into the sump  20 . 
     The washing fluid supplied into the sump  20  flows to the filter device  50  through the washing pump  70  and strongly collides with the first and second filters  52  and  54  such that the foreign materials attached to the first and second filters  52  and  54  may be separated from the first and second filters  52  and  54 . The separated foreign materials are directed to the draining device  59  due to the suction force of the draining pump  90  together with the washing fluid to be discharged to the outside. When the discharge of the foreign materials is completed, the draining pump  90  is turned off (S 63 ). 
     As described above, the draining pump  90  is driven before the driving of the washing pump  70  stops so that the level of the washing fluid may be lowered by a predetermined height. In this state, the filter cleaning cycle is performed so that the foreign materials may be easily discharged. 
       FIGS. 11 and 12  are cross-sectional views of filter housings of a dishwasher as embodied and broadly described herein. 
     Referring to  FIG. 11 , the pump inlet  58  is provided at one side of the filter housing  51  to supply washing fluid to the washing pump  70 . In this embodiment, the filter housing  51  may have an approximately cylindrical shape so as to receive the first and second filters  52  and  54  therein. In the above-mentioned cleaning cycle, the washing fluid, which back flows into the filter device  50  from the washing pump  70 , may flow to the center C of the filter housing  51  through the pump inlet  58 . The center C may correspond to the center of the first filter  52  and the second filter  54 , which may be concentrically aligned. In other words, in this embodiment, the pump inlet  58  may be oriented toward the center C of the filter housing  51  from the washing pump  70 . When so configured, washing fluid supplied from the pump inlet  58  to the filter device  50  collides with the first and second filters  52  and  54 , and foreign materials accumulated in the first and second filters  52  and  54  may be separated from the first and second filters  52  and  54 . 
     Alternatively, as shown in  FIG. 12 , the pump inlet  58  may extend in a tangential direction of the filter housing  51 . In the cleaning cycle, the washing fluid, which back flows from the pump inlet  58  which is spaced by a distance l 1  from the center C of the filter housing  51 , flows inside the filter housing  51  tangentially. The washing fluid flowing along the inner circumferential surface of the filter housing  51  removes foreign materials accumulated in the first and second filters  52  and  54  from the first and second filters  52  and  54 , thus preventing the first and second filters  52  and  54  from clogging due to the foreign materials. 
     A control method of a dishwasher may prevent a filter from being clogged by foreign materials by controlling an operation of a washing pump and a draining pump. 
     A control method of a dishwasher may clean foreign materials accumulated in a filter using washing water. 
     A control method of a dishwasher including a washing space that includes a first injecting nozzle and a second injecting nozzle having a higher height than that of the first injecting nozzle, a sump that is supplied with washing water injected into the washing space and passes the washing water to a filter, a washing pump that pressurizes the washing water supplied from the sump, a draining pump that is communicated with the sump and discharges the washing water in the sump to the outside, a channel controller that controls a channel to supply the washing water to the first injecting nozzle and the second injecting nozzle from the washing pump, and a washing water guide whose at least a part is adjacently disposed on one side of the washing space, as embodied and broadly described herein may include driving the washing pump; setting the channel controller to move the washing water to the second injecting nozzle direction; raising the washing water in the washing water guide; stopping the driving of the washing pump; back flowing the washing water to the washing pump from the washing water guide; and separating foreign materials attached to the filter by colliding the back flowing washing water with the filter. 
     A control method of a dishwasher including a washing space that includes a plurality of injecting nozzles, a sump that is supplied with washing water injected into the washing space and passes the washing water to a filter a washing pump that pressurizes the washing water supplied from the sump, a draining pump that is communicated with the sump and discharges the washing water in the sump to the outside, and a washing water guide that guides the washing water discharged from the washing pump to arrive at the injecting nozzle, in accordance with another embodiment as broadly described herein may include injecting the washing water into the washing space by driving the washing pump; driving the draining pump when the driving time of the washing pump elapses a first setting time; interrupting power supplied to the washing pump when the driving time of the draining pump elapses a second setting time; and separating foreign materials attached to the filter from the filter by back flowing the washing water to the sump from the washing water guide. 
     A control method of a dishwasher including a washing space that includes a first injecting nozzle and a second injecting nozzle having a higher height than that of the first injecting nozzle, a sump that is supplied with washing water injected into the washing space and passes the washing water to a filter, a washing pump that pressurizes the washing water supplied from the sump, a draining pump that is communicated with the sump and discharges the washing water in the sump to the outside, a channel controller that controls a channel to supply the washing water to the first injecting nozzle and the second injecting nozzle from the washing pump, and a washing water guide whose at least a part is adjacently disposed on one side of the washing space, in accordance with another embodiment as broadly described herein may include driving the washing pump; stopping the driving of the washing pump in the state where the driving time of the washing pump elapses a first setting time and the setting height of the washing water rises in the washing water guide; back flowing the washing water, which passes through the sump, to the sump; and separating foreign materials attached to the filter from the filter by the back flowing washing water. 
     In a control method of a dishwasher as embodied and broadly described herein, the washing water pumped by the washing pump may be strongly applied to the filter by the back flowing, thereby making it possible to separate the foreign materials from the filter. 
     In addition, the filter may be cleaned by controlling the operation of the washing pump or the draining pump without needing a separate filter cleaning unit, thereby making it possible to increase the cleaning efficiency of the filter at low cost. 
     Further, the foreign materials existing in the filter may be effectively cleaned and the flowing of the washing water is smoothly performed, thereby making it possible to improve the washing performance of the dishes. 
     Moreover, the foreign materials are removed from the filter surface to prevent the filter from clogging, thereby making it possible to improve the filtering performance of the washing water. 
     Further, the foreign materials separated from the filter may be discharged to the outside of the dishwasher in a draining cycle, thereby making it possible to prevent the occurrence of a bad smell due to the decay of the foreign materials. 
     Also, the washing performance and resulting cleanliness level of the dishes is improved and the foreign materials may be easily discharged, thereby making it possible to improve the reliability of the product. 
     Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments. 
     Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.