Abstract:
Disclosed herein are a dish washer which is capable of finishing a rinse mode within a predetermined time by changing an operation start time of a heater according to the temperature of washing water at the time of a final rinse mode of the dish washer, and a method of controlling the same. The method of controlling the dish washer including a washing tub for containing dishes to be washed using washing water and a heater for heating the washing water includes sensing a temperature of the washing water, determining an operation start time of the heater on the basis of the sensed temperature of the washing water, and operating the heater according to the determined operation start time of the heater.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the priority benefit of Korean Patent Application No. 2007-0062456, filed on Jun. 25, 2007 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    Embodiments relate to a dish washer and a method of controlling the same, and, more particularly, to a dish washer which is capable of performing a rinse mode within a predetermined time by changing an operation start time of a heater according to the temperature of washing water at the time of a final rinse mode, and a method of controlling the same. 
         [0004]    2. Description of the Related Art 
         [0005]    Generally, a dish washer for spraying cold or hot washing water to dishes at a high pressure and removing a contaminant (garbage) from the dishes is disclosed in Korean Unexamined Patent Publication No. 2005-0105721. 
         [0006]    The dish washer disclosed in the above Publication includes a washing tub which contains dishes to be washed, a plurality of dish baskets which is provided in the washing tub, for containing the dishes therein, spraying nozzles which are provided at the upper and lower sides of the plurality of dish baskets, for spraying washing water, and a sump which is connected to the spraying nozzles, for pumping the washing water to the spraying nozzles. 
         [0007]    In the dish washer, when washing water is supplied into the washing tub in a state in which dishes to be washed are contained in the dish baskets, a circulation pump included in the sump is operated so as to move the washing water to the spraying nozzles, and the washing water is then sprayed to the dishes at a high pressure so as to wash the dishes. A wash process (including a wash mode and a rinse mode) generally includes a main mode (a main wash mode or a final rinse mode) and a preliminary mode (a preliminary wash mode or a preliminary rinse mode), all of which are repeatedly performed four to six times according to a course. After the final rinse mode is finished, a drying mode for drying wet dishes using a heater is performed. 
         [0008]    In the conventional dish washer, the heater for heating the washing water is operated after a lapse of a predetermined time (after about 14 minutes) from starting of the final rinse mode such that the temperature of the washing water reaches a target temperature of about 60° C. (the temperature of the washing water necessary for improving rinse performance and drying performance). Thus, it is possible to improve the rinse performance of the rinse mode and the drying performance of the drying mode after the rinse mode is finished. 
         [0009]    In the conventional dish washer, since the operation of the heater is started after the lapse of the predetermined time from the starting of the final rinse mode (after about 14 minutes), if the temperature of the washing water supplied for the rinse mode is low, it takes much time for the temperature of the washing water to reach the target temperature (about 60° C.) and thus a final rinse time becomes longer than a predetermined time (about 30 minutes). Referring to  FIG. 1 , when the temperature of the washing water is equal to or greater than 49° C. and the heater is operated after the lapse of the predetermined time (after about 14 minutes) from the starting of the final rinse mode, the temperature of the washing water reaches the target temperature when the final rinse mode is finished (see (a) of  FIG. 1 ). In contrast, when the temperature of the washing water is less than 49° C. and the heater is operated after the lapse of the predetermined time (after about 14 minutes) from the starting of the final rinse mode, the temperature of the washing water does not reach the target temperature (about 60° C.) when the final rinse mode is finished. Accordingly, since the heater is continuously operated until the temperature of the washing water reaches the target temperature (about 60° C.), the operation time of the heater becomes longer and thus a rinse time becomes longer (see (b) of  FIG. 1 ). If the rinse time becomes longer, the subsequent drying mode is delayed and an actual washing time becomes different from a total washing time displayed to a user, thereby leading to dissatisfaction of the user. 
       SUMMARY 
       [0010]    In an aspect of embodiments, there is provided a dish washer which is capable of finishing a rinse mode within a predetermined time by sensing the temperature of washing water and changing an operation start time of a heater at the time of a final rinse mode, and a method of controlling the same. 
         [0011]    In another aspect of embodiments, there is provided a dish washer which is capable of preventing a mode from being delayed and improving drying performance by changing an operation start time of a heater according to the temperature of washing water at the time of a final rinse mode such that a start time of the drying mode is always uniformly maintained, and a method of controlling the same. 
         [0012]    In an aspect of embodiments, there is provided a method for controlling a dish washer including a washing tub for containing dishes to be washed using washing water and a heater for heating the washing water, the method including: sensing a temperature of the washing water; determining an operation start time of the heater based on the sensed temperature of the washing water; and operating the heater based on the determined operation start time of the heater. 
         [0013]    According to another aspect of embodiments, there is provided a method for controlling a dish washer, the method including: sensing a temperature of washing water while dishes are washed using the washing water; determining a heating start time of the washing water based on the sensed temperature of the washing water; and operating a heater based on the determined heating start time of the washing water and heating the washing water. 
         [0014]    The sensing of the temperature of the washing water may include sensing the temperature of the washing water at the time of a final rinse mode of the dish washer. 
         [0015]    The sensing of the temperature of the washing water may include sensing the temperature of the washing water immediately after the supply of the washing water necessary for the final rinse mode is finished. 
         [0016]    The determining of the operation start time of the heater may include determining the operation start time of the heater such that the temperature of the washing water reaches a target temperature when the final rinse mode is finished. 
         [0017]    The determining of the operation start time of the heater may include determining a heating start time of the washing water such that the operation start time of the heater after starting the final rinse mode is advanced as the temperature of the washing water is decreased. 
         [0018]    The determining of the heating start time of the washing water may include determining the operation start time of the heater such that the temperature of the washing water reaches a target temperature when the final rinse mode is finished. 
         [0019]    The determining of the heating start time of the washing water may include determining the heating start time of the washing water such that the operation start time of the heater after starting the final rinse mode is advanced as the temperature of the washing water is decreased. 
         [0020]    In an aspect of embodiments, there is provided a method for controlling a dish washer including a washing tub for containing dishes to be washed using washing water and a heater for heating the washing water, the method including: sensing a temperature of the dish washer while the dishes are washed using the washing water; and determining an operation start time of the heater such that the sensed temperature of the dish washer reaches a target temperature within a predetermined time. 
         [0021]    The sensing of the temperature of the dish washer may include sensing the temperature of the washing water at the time of a final rinse mode of the dish washer. 
         [0022]    The sensing of the temperature of the dish washer may include sensing the temperature of the washing tub at the time of a rinse mode of the dish washer. 
         [0023]    The predetermined time may be a rinse time. 
         [0024]    According to another aspect of embodiments, there is provided a dish washer including: a washing tub which contains dishes to be washed using washing water; a heater which heats the washing water; a temperature sensing unit which senses a temperature of the washing water; and a control unit which determines an operation start time of the heater based on the sensed temperature of the washing water and which controls an operation of the heater based on the determined operation start time of the heater. 
         [0025]    The temperature sensing unit may sense the temperature of the washing water at the time of a final rinse mode of the dish washer. 
         [0026]    The temperature sensing unit may sense the temperature of the washing water immediately after the supply of the washing water necessary for the final rinse mode is finished. 
         [0027]    The control unit may determine the operation start time of the heater such that the temperature of the washing water reaches a target temperature when the final rinse mode is finished. 
         [0028]    The control unit may determine a heating start time of the washing water such that the operation start time of the heater after starting the final rinse mode is advanced as the temperature of the washing water is decreased. 
         [0029]    According to another aspect of embodiments, there is provided a method for controlling dish washer having a heater and containing washing water, the method including determining an operation start time of the heater such that a temperature of the washing water of the dish washer reaches a target temperature within a predetermined time; and operating the heater based on the determined operation start time to heat the washing water. 
         [0030]    According to another aspect of embodiments, there is provided a dish washer including a washing tub which contains dishes to be washed using washing water; a heater to heat the washing water; a temperature sensor to sense a temperature of the washing water; and a control unit to determine an operation start time of the heater based on the sensed temperature of the washing water such that the temperature of the washing water reaches a target temperature within a predetermined time and to control an operation of the heater based on the determined operation start time of the heater to heat the washing water. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0031]    These and/or other aspects, features, and advantages will become apparent and more readily appreciated from the following description of exemplary embodiments, taken in conjunction with the accompanying drawings of which: 
           [0032]      FIG. 1  is a graph showing an operation start time of a heater of a conventional dish washer; 
           [0033]      FIG. 2  is a side cross-sectional view showing the configuration of a dish washer according to an exemplary embodiment; 
           [0034]      FIG. 3  is a block diagram showing the control configuration of the dish washer according to an exemplary embodiment; 
           [0035]      FIG. 4  is a flowchart illustrating a method of controlling the dish washer according to an exemplary embodiment; and 
           [0036]      FIG. 5  is a graph showing an operation start time of a heater of the dish washer according to an exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0037]    Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. Exemplary embodiments are described below by referring to the figures. 
         [0038]      FIG. 2  is a side cross-sectional view showing the configuration of a dish washer according to an exemplary embodiment. 
         [0039]    In  FIG. 2 , the dish washer according to an exemplary embodiment includes a main body  10  having a washing space therein and a door  12  for opening and closing a front surface of the main body  10 , both of which form an appearance. 
         [0040]    The main body  10  includes a washing tub  20  which contains dishes to be washed. The washing tub  20  includes upper and lower dish baskets  22   a  and  22   b  which contain dishes therein, racks  24   a  and  24   b  for slidably supporting the upper and lower dish baskets  22   a  and  22   b , and an upper spraying nozzle  26   a , a middle spraying nozzle  26   b  and a lower spraying nozzle  26   c  which are provided above and below the upper and lower dish baskets  22   a  and  22   b , for spraying washing water. 
         [0041]    The upper spraying nozzle  26   a  and the middle spraying nozzle  26   b  are connected to a sump  42  through a first supply pipe  28   a  and the lower spraying nozzle  26   c  is connected to the sump  42  through a second supply pipe  28   b , thereby receiving the washing water. 
         [0042]    The washing water supplied to the upper spraying nozzle  26   a  and the middle spraying nozzle  26   b  through the first supply pipe  28   a  and the washing water supplied to the lower spraying nozzle  26   c  through the second supply pipe  28   b  are separately sprayed according to the operation of the upper spraying nozzle  26   a  and the middle spraying nozzle  26   b  or the operation of the lower spraying nozzle  26   c . In this case, a channel switching device may be separately provided or valves may be provided to the first and second supply pipes  28   a  and  28   b.    
         [0043]    Meanwhile, a plurality of spraying holes for spraying the washing water to the upper side of the middle spraying nozzle  26   b  and a plurality of spraying holes for spraying the washing water to the lower side of the middle spraying nozzle  26   b  are formed in the middle spraying nozzle  26   b  such that the washing water is simultaneously sprayed to the upper and lower sides of the middle spraying nozzle  26   b.    
         [0044]    A heater  30  for heating the washing water is provided on the bottom of the washing tub  20  and is contained in a heater installation groove  32  formed in the bottom of the washing tub  20 . 
         [0045]    A mechanical chamber  40  is provided below the washing tub  20 . The sump  42  for collecting, pumping and moving the washing water to be supplied into the washing tub  20  to the upper, middle and lower spraying nozzles  26   a ,  26   b  and  26   c  is provided in the mechanical chamber  40 . A temperature sensor  44  for sensing the temperature of the washing water is provided in the sump  42 . 
         [0046]    A variety of channels and a circulation pump  46  for pumping water to the channels are provided in the sump  42 . A water draining pump  48  and a water draining valve  50  for draining contaminated washing water through a water draining pipe  52  are provided at one side of the sump  42 . 
         [0047]      FIG. 3  is a block diagram showing the control configuration of the dish washer according to an exemplary embodiment. The dish washer includes a water level detecting unit  58 , an input unit  60 , a control unit  62 , a driving unit  64  and a display unit  68  in addition to the elements shown in  FIG. 2 . 
         [0048]    The water level detecting unit  58  detects the amount (water level) of the washing water supplied to the washing tub  20 . The input unit  60  inputs a variety of washing courses (e.g., a standard course and a manual course) and operation information such as the temperature of the washing water and the addition of the rinse mode to the control unit  62  by a command of a user. 
         [0049]    The washing course includes a standard course for sequentially performing a water supplying mode for supplying washing water, a wash mode for spraying the washing water to the dishes and washing the dishes, a heating mode for heating the washing water to a temperature suitable for the wash and the rinse before spraying the washing water to the dishes, a water draining mode for draining the washing water after the wash, and a drying mode for drying the washed dishes after the wash. The washing course also includes a manual course for allowing the user to optionally select and operate the modes. 
         [0050]    The control unit  62  is a microprocessor which operates the dish washer according to the operation information input through the input unit  60  and controls the wash, rinse and drying modes. At the time of a final rinse mode, the control unit  62  senses the temperature of the washing water supplied into the washing tub  20  through the temperature sensor  44  and changes the operation start time of the heater  30  according to the sensed temperature of the washing water as follows. 
         [0051]    (1) If the temperature of the washing water is equal to or greater than 49° C., then the heater  30  is operated after 14 minutes from the starting of the final rinse. 
         [0052]    (2) If the temperature of the washing water is in a range from 45 to 48° C., then the heater  30  is operated after 12 minutes from the starting of the final rinse. 
         [0053]    (3) If the temperature of the washing water is in a range from 41 to 44° C., then the heater  30  is operated after 10 minutes from the starting of the final rinse. 
         [0054]    (4) If the temperature of the washing water is in a range from 35 to 40° C., then the heater  30  is operated after 8 minutes from the starting of the final rinse. 
         [0055]    (5) If the temperature of the washing water is in a range from 30 to 34° C., then the heater  30  is operated after 5 minutes from the starting of the final rinse. 
         [0056]    (6) If the temperature of the washing water is in a range from 25 to 29° C., then the heater  30  is operated after 3 minutes from the starting of the final rinse. 
         [0057]    (7) If the temperature of the washing water is less than 24° C., then the heater  30  is simultaneously operated when the final rinse mode is started. 
         [0058]    When the control unit  62  changes the operation start time of the heater  30  according to the temperature of the washing water, the temperature of the washing water reaches the target temperature (about 60° C.) when the final rinse mode is finished (after about 30 minutes). Accordingly, the operation of the heater  30  and the final rinse mode are simultaneously finished such that the rinse mode is not delayed and drying performance is improved. 
         [0059]    When the temperature of the washing water is equal to or greater than 49° C., the control unit  62  divides the temperature range of the washing water by 3° C. and delays the operation start time of the heater  30  by 3 minutes according to the divided temperature range of the washing water as follows. 
         [0060]    (8) If the temperature of the washing water is in a range from 49 to 52° C., then the heater  30  is operated after 17 minutes from the starting of the final rinse mode. 
         [0061]    (9) If the temperature of the washing water is in a range from 53 to 56° C., then the heater  30  is operated after 20 minutes from the starting of the final rinse mode. 
         [0062]    (10) If the temperature of the washing water is in a range from 57 to 60° C., then the heater  30  is operated after 23 minutes from the starting of the final rinse mode. 
         [0063]    The control unit  62  performs the water supplying mode for opening the water supply valve  66  and supplying the washing water into the washing tub  20  at the time of the wash and rinse modes, the heating mode for operating the heater  30  and heating the washing water supplied into the washing tub  20  after supplying the water, the wash (or the rinse) mode for driving the circulation pump  46 , spraying the washing water supplied into the washing tub  20  or heated washing water, and washing (or rinsing) dishes after supplying the water, and the water draining mode for opening the water draining valve  50 , driving the water draining pump  48  and draining the washing water from the washing tub  20  after the wash. 
         [0064]    The driving unit  64  drives the heater  30 , the circulation pump  46 , the water draining pump  48 , the water draining valve  50 , and the water supply valve  66  according to a drive control signal of the control unit  62 . The water supply valve  66  controls the supply of the washing water supplied into the washing tub  20 . 
         [0065]    The display unit  68  displays an operation state (e.g., a total mode time) and an error of the dish washer according to a display control signal of the control unit  62 . 
         [0066]    Hereinafter, the operation and the effect of the dish washer and the method of controlling the same will be described. 
         [0067]      FIG. 4  is a flowchart illustrating a method of controlling the dish washer according to an exemplary embodiment. 
         [0068]    When a user selects a wash course (e.g., the standard course) and desired operation information in a state in which dishes to be washed are contained in the dish baskets  22   a  and  22   b  of the washing tub  20 , the operation information selected by the user is input to the control unit  62  through the input unit  60 . 
         [0069]    Accordingly, the control unit  62  starts to sequentially perform a preliminary wash mode (a washing time of about 15 minutes), a main wash mode (a washing time of about 30 minutes and a temperature of washing water of about 50° C.), a preliminary rinse mode (a rinse time of about 5 minutes), a final rinse mode (a rinse time of about 30 minutes and a temperature of rinsing water of about 60° C.), and a drying mode. At this time, the control unit  62  displays the total washing time of the modes through the display unit  68  such that the user can easily confirm the washing time. 
         [0070]    Thereafter, the control unit  62  determines whether a mode which is currently being performed is the final rinse mode ( 100 ). If it is determined to be the final rinse mode, the control unit  62  operates the water supply valve  66  through the driving unit  64  such that the washing water necessary for the final rinse mode is supplied into the washing tub  20  and the washing water supplied into the washing tub  20  is collected in the sump  42  provided below the washing tub  20  ( 102 ). 
         [0071]    When the washing water necessary for the final rinse mode is supplied, the amount of washing water supplied into the washing tub  20  is detected by the water level detecting unit  58  such that the washing water is supplied up to a predetermined water level (a water level necessary for the final rinse mode). 
         [0072]    When the washing water is supplied up to the predetermined water level, the temperature Tw of the supplied washing water is sensed by the temperature sensor  44  provided in the sump  42  and is input to the control unit  62  ( 104 ). 
         [0073]    The control unit  62  determines the operation start time of the heater  30  according to the temperature Tw of the washing water sensed by the temperature sensor  44  as follows. 
         [0074]    (1) If the temperature of the washing water is equal to or greater than 49° C., then the heater  30  is operated after 14 minutes from the starting of the final rinse. 
         [0075]    (2) f the temperature of the washing water is in a range from 45 to 48° C., then the heater  30  is operated after 12 minutes from the starting of the final rinse. 
         [0076]    (3) If the temperature of the washing water is in a range from 41 to 44° C., then the heater  30  is operated after 10 minutes from the starting of the final rinse. 
         [0077]    (4) If the temperature of the washing water is in a range from 35 to 40° C., then the heater  30  is operated after 8 minutes from the starting of the final rinse. 
         [0078]    (5) If the temperature of the washing water is in a range from 30 to 34° C., then the heater  30  is operated after 5 minutes from the starting of the final rinse. 
         [0079]    (6) If the temperature of the washing water is in a range from 25 to 29° C., then the heater  30  is operated after 3 minutes from the starting of the final rinse. 
         [0080]    (7) If the temperature of the washing water is less than 24° C., then the heater  30  is simultaneously operated when the final rinse mode is started. 
         [0081]    After the control unit  62  determines the operation start time of the heater  30  according to the temperature Tw of the washing water, the washing water is moved to the upper spraying nozzle  26   a , the middle spraying nozzle  26   b  and the lower spraying nozzle  26   c  through the first and second supply pipes  28   a  and  28   b  by the pumping operation of the circulation pump  46 , and the washing water is sprayed to the dishes contained in the dish baskets  22  at a high pressure such that the final rinse mode for removing fine particles stuck to the dishes is started ( 108 ). 
         [0082]    When the temperature of the washing water is equal to or greater than 49° C., the control unit  62  divides the temperature range of the washing water by 3° C. and delays the operation start time of the heater  30  by 3 minutes according to the divided temperature range of the washing water as follows. 
         [0083]    (8) If the temperature of the washing water is in a range from 49 to 52° C., then the heater  30  is operated after 17 minutes from the starting of the final rinse mode. 
         [0084]    (9) If the temperature of the washing water is in a range from 53 to 56° C., then the heater  30  is operated after 20 minutes from the starting of the final rinse mode. 
         [0085]    (10) If the temperature of the washing water is in a range from 57 to 60° C., then the heater  30  is operated after 23 minutes from the starting of the final rinse mode. 
         [0086]    When the final rinse mode is started, the control unit  62  counts a rinse time and determines whether the time reaches the operation start time of the heater  30  determined according to the temperature Tw of the washing water ( 110 ). If it is determined that the time reaches the operation start time of the heater  30 , the heater  30  is operated by the driving unit  64  ( 112 ), as shown in  FIG. 5 . 
         [0087]    When the heater  30  is operated at the operation start time of the heater  30 , determined according to the temperature Tw of the washing water in the final rinse mode, the washing water collected in the sump  42  is heated such that the temperature of the washing water is increased. 
         [0088]    Thereafter, the control unit  62  counts a final rinse time and determines whether a predetermined final rinse time (about 30 minutes) elapses, that is, whether the final rinse mode is finished ( 114 ). If it is determined that the final rinse is not finished, then the final rinse mode is performed while the heater  30  is continuously operated until the final rinse time elapses. 
         [0089]    When the heater  30  is continuously operated from the operation start time of the heater  30 , determined according to the temperature Tw of the washing water during the final rinse time, the temperature Tw of the washing water reaches the target temperature when the final rinse mode is finished (after about 30 minutes) such that the operation of the heater  30  and the final rinse mode are simultaneously finished. Thus, the rinse mode is not delayed and the drying performance is improved. 
         [0090]    At this time, the control unit  62  displays a residual washing time through the display unit  68  as the modes progress, such that the user can easily confirm the residual washing time. 
         [0091]    Although the operation start time of the heater  30  is changed according to the temperature Tw of the supplied washing water in an exemplary embodiment embodiments are not limited to this. Even when the operation start time of the heater  30  is changed according to an internal temperature of the washing tub  20 , the same object and effect can be realized. 
         [0092]    If it is determined that the final rinse mode is finished in Operation  114 , the washing water and a fine contaminant stuck to the dishes are collected to the sump  42 . The control unit  62  drains the washing water containing the contaminant through the water draining pipe  52  according to the operation of the water draining pump  48  and the water draining valve  50  ( 116 ) and performs the drying mode ( 118 ). 
         [0093]    As described above, in the dish washer and the method of controlling the same according to an exemplary embodiment, since the temperature of the washing water is sensed to control the operation start time of the heater at the time of the final rinse mode, it is possible to finish the rinse mode within a predetermined time. 
         [0094]    Since the operation start time of the heater is controlled according to the temperature of the washing water at the time of the final rinse mode such that the start time of the drying mode is always uniformly maintained regardless of the temperature of the washing water, the mode is not delayed and the drying performance is improved. Since an actual washing time is equal to the total washing time displayed to the user, it is possible to eliminate the dissatisfaction of the user. 
         [0095]    Although a few exemplary embodiments have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these exemplary embodiments, the scope of which is defined in the claims and their equivalents.