Washing machine and method for controlling the same

Abstract

Method for controlling a washing machine having a drum of which rotation speed is adjustable, including a first step for rotating the drum at a first rotation speed set at control unit, a second step for detecting whether resonance occurs or not at the drum rotating at the first rotation speed, and a third step for changing the rotation speed of the drum if the resonance is detected at the drum.

1 . A method for controlling a washing machine having a drum of which rotation speed is adjustable, comprising: 
 a first step for rotating the drum at a first rotation speed set at control unit;    a second step for detecting whether resonance occurs or not at the drum rotating at the first rotation speed; and    a third step for changing the rotation speed of the drum if the resonance is detected at the drum.    
   
   
       2 . The method as claimed in  claim 1 , wherein the third step includes the step of storing the changed rotation speed in the control unit.  
   
   
       3 . The method as claimed in  claim 2 , wherein the drum is rotated at the changed rotation speed when the washing machine is put into operation again after the washing machine is stopped.  
   
   
       4 . The method as claimed in  claim 1 , wherein the third step further includes the step of measuring eccentricity of laundry held in the drum rotating at the changed rotation speed.  
   
   
       5 . The method as claimed in  claim 4 , wherein the step of decreasing the rotation speed of the drum again after increasing the rotation speed of the drum is repeated, if the eccentricity is greater than a preset value.  
   
   
       6 . The method as claimed in  claim 4 , wherein the drum is rotated in regular/reverse directions alternately for a plurality of times, if the eccentricity exceeds a preset value.  
   
   
       7 . The method as claimed in  claim 4 , wherein, in a case the eccentricity is below the preset value, the third step further includes the steps of; 
 rotating the drum at the set second rotation speed for extracting water from the laundry,    detecting whether the resonance occurs at the drum rotating at the second rotation speed or not,    changing the rotation speed of the drum, if the resonance is detected at the drum, and    storing the changed rotation speed in the control unit.    
   
   
       8 . The method as claimed in  claim 1 , further comprising the step of measuring the eccentricity of the laundry held in the drum, if no resonance occurs in the second step.  
   
   
       9 . The method as claimed in  claim 8 , wherein the step of decreasing the rotation speed of the drum again after increasing the rotation speed of the drum is repeated, if the eccentricity is greater than a preset value.  
   
   
       10 . The method as claimed in  claim 8 , wherein the drum is rotated in regular/reverse directions alternately for a plurality of times, if the eccentricity exceeds a preset value.  
   
   
       11 . The method as claimed in  claim 8 , wherein, in a case the eccentricity is below the preset value, further includes the steps of; 
 rotating the drum at the set second rotation speed for extracting water from the laundry,    detecting whether the resonance occurs at the drum rotating at the second rotation speed or not,    changing the rotation speed of the drum, if the resonance is detected at the drum, and    storing the changed rotation speed in the control unit.    
   
   
       12 . The method as claimed in  claim 1 , wherein the rotation speed of the drum increases in the third step.  
   
   
       13 . The method as claimed in  claim 1 , wherein the rotation speed of the drum decreases in the third step.  
   
   
       14 . The method as claimed in  claim 1 , wherein the rotation speed of the drum changes by predetermined magnitudes each greater than 50 rpm in the third step.  
   
   
       15 . The method as claimed in  claim 1 , wherein the resonance of the drum is detected by a resonance detecting device automatically in the second step.  
   
   
       16 . The method as claimed in  claim 15 , wherein the third step is performed automatically by the control unit which receives a signal from the resonance detecting device.  
   
   
       17 . The method as claimed in  claim 1 , wherein the second step includes the step of sounding alarm through a speaker if the resonance of the drum is detected.  
   
   
       18 . The method as claimed in  claim 1 , wherein the steps are performed in a state a test mode is selected.  
   
   
       19 . A method for controlling a washing machine having a drum of which rotation speed is adjustable for extracting water from laundry, comprising: 
 a first step for rotating the drum at a second rotation speed set at a control unit;    a second step for increasing the rotation speed from the second rotation speed by predetermined magnitudes of rpm in succession, and whether resonance occurs or not at every rotation speed section is detected;    a third step for changing the rotation speed of the drum when resonance of the drum is detected; and    a fourth step for storing the changed rotation speed in the control unit.    
   
   
       20 . The method as claimed in  claim 19 , wherein the first step includes the steps of; 
 selecting one of course relevant to a kind of laundry, and    rotating the drum at the second rotation speed for the selected course.    
   
   
       21 . The method as claimed in  claim 19 , wherein the rotation speed of the drum increases in the third step.  
   
   
       22 . The method as claimed in  claim 19 , wherein the rotation speed of the drum decreases in the third step.  
   
   
       23 . The method as claimed in  claim 19 , wherein the rotation speed of the drum changes by predetermined magnitudes each greater than 50 rpm in the third step.  
   
   
       24 . The method as claimed in  claim 19 , wherein the steps are performed in a state a test mode is selected.  
   
   
       25 . The method as claimed in  claim 24 , wherein the drum is rotated at the changed rotation speed when the washing machine is put into operation again after the test mode is finished.  
   
   
       26 . The method as claimed in  claim 25 , wherein, not the changed rotation speed, but the second rotation speed is displayed on a display, when the washing machine is put into operation again after the washing machine is stopped.  
   
   
       27 . The method as claimed in  claim 19 , wherein the fourth step includes the step of sounding an alarm from a speaker when the changed rotation speed is stored.  
   
   
       28 . The method as claimed in  claim 19 , wherein the third step is performed automatically by the control unit having the signal received from a resonance detecting device.  
   
   
       29 . The method as claimed in  claim 19 , wherein the second step includes the step of automatic detection of resonance occurrence at the drum by the resonance detecting device.  
   
   
       30 . The method as claimed in  claim 19 , wherein the second step further includes the step of storing a preset maximum rotation speed in the control unit in a case no resonance occurs until the drum rotates up to the preset maximum speed.  
   
   
       31 . The method as claimed in  claim 19 , wherein the second step further includes the step of sounding an alarm from a speaker if the resonance of the drum is detected.  
   
   
       32 . A washing machine comprising: 
 a motor for generating rotating force;    a drum for being rotated upon receiving driving force from the motor;    a sensor for sensing rotation speed of the drum;    a vibration detecting device for transmitting a signal if vibration greater than a preset value is detected at the drum; and    a control unit for adjusting the rotation speed of the motor to prevent the resonance of the drum from occurring upon reception of the signal.    
   
   
       33 . The washing machine as claimed in  claim 32 , further comprising a rotary key electrically connected to the control unit for a user to turn to change the rotation speed of the drum.  
   
   
       34 . The washing machine as claimed in  claim 32 , further comprising a selection button connected to the control unit for selecting a course for a kind of laundry.  
   
   
       35 . The washing machine as claimed in  claim 32 , further comprising a storage button connected to the control unit for storing an adjusted rotation speed.  
   
   
       36 . The washing machine as claimed in  claim 32 , further comprising a test mode button connected to the control unit for performing a test mode to search a rotation speed at which the resonance of the drum occurs.  
   
   
       37 . The washing machine as claimed in  claim 32 , further comprising a speaker connected to the control unit for sounding an alarm when a working rotation speed is stored.  
   
   
       38 . The washing machine as claimed in  claim 32 , further comprising a display for displaying a rotation speed of the drum sensed at the sensor.