Patent Publication Number: US-2012036650-A1

Title: Laundry machine and control method thereof

Description:
TECHNICAL FIELD 
     The present invention relates to a laundry machine and a control method thereof. 
     BACKGROUND ART 
     In general, in the laundry machine, there are washing machines for washing, dryers for drying, and washing and drying machines for washing and drying. The laundry machine, provided with a washing course, a rinsing course, a spinning or drying course, processes washing objects. 
     DISCLOSURE OF INVENTION 
     Technical Problem 
     An object of the present invention is to provide a laundry machine and a control method thereof which can remove moisture from a washing object more effectively. 
     Solution to Problem 
     To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a laundry machine includes a cabinet, a tub in the cabinet for holding washing water, a drum rotatably mounted in the tub, a heater in the tub for heating the washing water, and a control unit for controlling the heater and the drum, wherein the control unit controls the heater to operate selectively in a spinning course for drying washing objects. 
     The control unit turns on/off the heater in predetermined periods, or the control unit controls the heater to operate below a predetermined temperature so that the heater is not overheated. 
     In the meantime, the control unit controls the drum to rotate higher than a predetermined speed. 
     In another aspect of the present invention, a method for controlling a laundry machine having a washing course, a rinsing course and a spinning course, includes the steps of driving a heater in the spinning course selectively, and rotating a drum higher than a predetermined speed. 
     ADVANTAGEOUS EFFECTS OF INVENTION 
     The laundry machine and the control method thereof of the present invention have following advantageous effects. 
     The preliminary drying step of the present invention permits to remove moisture from the washing objects more than a predetermined amount, thereby permitting drying the washing objects faster than drying the washing objects naturally, or with a laundry machine having a drying function. 
     Moreover, the laundry machine and the control method thereof of the present invention enable to remove moisture from the washing objects without providing heating means to the laundry machine additionally. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The accompanying drawings, which are included to provide further understanding of the disclosure and are incorporated in and constitute a part of this application, illustrate embodiments of the disclosure and together with the description serve to explain the principle of the disclosure. 
       In the drawings: 
         FIG. 1  illustrates a longitudinal section of a laundry machine in accordance with a preferred embodiment of the present invention; 
         FIG. 2  illustrates a flow chart showing the steps of a method for controlling a laundry machine in accordance with a preferred embodiment of the present invention; 
         FIG. 3  illustrates a longitudinal section of a laundry machine in accordance with another preferred embodiment of the present invention; and 
         FIG. 4  illustrates a flow chart showing the steps of a method for controlling a laundry machine in accordance with another preferred embodiment of the present invention. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Reference will now be made in detail to the specific embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
       FIG. 1  illustrates a longitudinal section of a laundry machine in accordance with a preferred embodiment of the present invention. 
     Referring to  FIG. 1 , the laundry machine includes a cabinet  110  which forms an exterior of the laundry machine, a tub  120  mounted in the cabinet  110  for holding washing water, a drum  130  rotatably mounted in the tub  120 , and a control unit (not shown) for controlling the laundry machine. 
     The cabinet  110  has a body  111  which forms sides, a rear and a bottom of the laundry machine, a front plate  112  which forms a front of the laundry machine, and a top plate  113  coupled to a top of the body  111  to form a top surface of the body. The front plate  112  which forms the front of the cabinet  110  has a laundry opening  112   a  for introduction of laundry therethrough. The laundry opening  112   a  is provided with a door for opening/closing the laundry opening  112   a.    
     Mounted to one side of the cabinet  110 , there may be an input unit  180  for user&#39;s operation of the laundry machine. The user can input a desired course of the laundry machine through the input unit  180 . Moreover, the input unit  180  has a display unit (not shown) for displaying information on the laundry machine. 
     In the meantime, the tub  120 , mounted in the cabinet,  110  has an upper portion suspended from an upper side of an inside of the cabinet  110  by springs  121 , and a lower portion supported on a damper  122 . The springs  121  and the dampers  122  support the tub  120  and attenuate vibration from the drum  130  to the tub  120  when the drum  130  rotates at a high speed. 
     The drum  130  is mounted in the tub  120  so as to be rotatable in a regular or reverse direction. The control unit makes the drum  130  to rotate for progressing washing, rinsing, and spinning. Mounted on an inside circumference of the drum  130 , there may be lifters  131  for lifting the laundry introduced to the drum  130  to a predetermined position. The drum  130  has a plurality of pass through holes  132  formed therein, for the washing water to enable to move in/out of the drum  130  in a washing course, and rinsing course. 
     Mounted in the cabinet  110 , there are a water supply hose  140  for supplying water to the tub  120  from an external water supply source, a water supply valve  141  mounted to the water supply hose  140  for controlling in/out of the water, and a detergent supply unit  142  for holding detergent therein such that the water being supplied through the water supply hose  140  is introduced to the inside of the tub  120  together with the detergent. The washing water or rinsing water is supplied from the water supply source to the inside of the tub  120  through the detergent supply unit  142  following the water supply hose  140 . Also, mounted in the cabinet  110 , there are a drain hose  150  and a drain pump  151  for draining the washing water used in the washing course or the rinsing course to an outside of the laundry machine. 
     In the meantime, mounted in a rear or the tub  120 , there is a driving unit  160 , such as a motor. The driving unit  160  coupled to the drum  130  through a rotation shaft  165 , for rotating the drum  130 . 
     In a case the washing course and the rinsing course are carried out by using the laundry machine, the course may be progressed by using water heated by selection of the user or a course selected by the user. In a case heated water is required thus, a heater  125  may be provided to the inside of the tub  120  for heating the water. Moreover, a temperature sensor (not shown) may be mounted to the inside of the tub  120  for measuring a temperature of the washing water, additionally. Accordingly, the control unit puts the heater  125  into operation to heat the water in the tub  120  if heated water is required, and measures the temperature of the water with the temperature sensor, for heating the water to a desired temperature. 
     In general, the laundry machine having above system washes the washing objects by introducing the washing objects into the drum  130 , supplying the washing water and the detergent into the drum  130  and the tub  120 , and rotating the drum  130 . Upon finishing the washing course, the washing objects are rinsed in the rinsing course to remove residual detergent from the washing objects, and moisture is removed from the washing objects in the spinning course, firstly. 
     However, even if the moisture is removed from the washing objects in the spinning course, the user can not put on the washing objects, the clothes, at once, but the user can put on the clothes only after the clothes is passed through a drying step. The drying step can be made outdoors naturally by sunshine or wind, or by a laundry machine having a drying function on the drying objects taken out of the laundry machine after finishing the spinning course. In a case the drying step is made outdoors naturally, though it has advantage in that no energy is consumed together with a sterilizing effect, it has disadvantage in that comparatively long drying time period is required. Therefore, if the moisture is removed from the washing objects before the drying step, the drying time period can be shortened even in the case the drying step is made naturally, which will be described in detail. 
     The present invention includes a preliminary drying step for removing a predetermined amount of moisture from the drying objects before starting the drying step of the drying objects. As described before, the drying step includes the drying made in outdoors naturally and the drying made at the laundry machine having a drying function. 
       FIG. 2  illustrates a flow chart showing the steps of a method for controlling a laundry machine in accordance with a preferred embodiment of the present invention. 
     Referring to  FIG. 2 , the control method includes a washing course S 210 , a rinsing course S 230 , and a spinning course, and in the spinning course, the preliminary drying step is performed at the same time S 250 . 
     Since the washing course and the rinsing course are similar to the related art laundry machine, detailed description of this will be omitted. 
     In detail, the preliminary drying step can be performed in the spinning course. If the preliminary drying step is performed in the spinning course, since no separate rotation of the drum  130  is required in the preliminary drying step in addition to the spinning course, it is favorable in view of energy saving. 
     Upon finishing draining at an end of the rinsing course, the control unit puts the heater  125  into operation. In this case, since there is almost no washing water remained in the tub  120  after the rinsing is almost finished, if the heater  125  is kept turned on for a long time period, the heater  125  is likely to be overheated to malfunction. Therefore, it is preferable that the control unit controls the heater  125  such that the heater  125  is turned on/off in predetermined periods for preventing the heater  125  from overheating. 
     If the heater  125  is turned on/off in predetermined periods, is possible to heat environmental air of the heater  125  while preventing the heater  125  from overheating. 
     Then, the control unit makes the drum  130  to rotate at a speed higher than a predetermined speed for performing the spinning course. If the drum  130  is rotated at the speed higher than a predetermined speed, the moisture is removed from the washing objects by centrifugal force, firstly. Moreover, the rotation of the drum  130  generates an air flow in the drum  130 . According to this, the air heated by the heater  125  can flow following the rotation of the drum  130  and can be supplied to the washing objects. As the heated air is supplied to the washing objects, the moisture remained at the washing objects can be removed, secondly. 
     In the meantime,  FIG. 3  illustrates a longitudinal section of a laundry machine in accordance with another preferred embodiment of the present invention. The laundry machine in  FIG. 3  is different from the foregoing laundry machine in that the laundry machine in  FIG. 3  includes an air flow passage  170  which makes an inside and an outside of the tub  120  into communication. 
     Accordingly, the laundry machine of the embodiment may be provided with a fan  172  mounted to the air flow passage  170  for causing an air flow in the tub  120  and the drum  130 . That is, it is possible that the heater is put into operation for heating the air, and the fan on the air flow passage  170  is put into operation to cause the air flow in the drum  130 . By this, it is made possible that the heated air is supplied to the washing objects. 
     Eventually, the laundry machine of the present invention does not remove the moisture from the washing objects merely by centrifugal force owing to rotation of the drum like the spinning course in the related art, but, in addition to this, removes the moisture from the washing objects more effectively by supplying the heated air to the washing objects. 
     In the meantime, the preliminary drying step can be performed before or after the spinning course. 
       FIG. 4  illustrates a flow chart showing the steps of a method for controlling a laundry machine in accordance with another preferred embodiment of the present invention.  FIG. 4  illustrates an embodiment in which the preliminary drying step is performed after finishing the spinning course. For an example, according to the user&#39;s course selection, a course can be set such that the preliminary drying step is performed at an end of the course after the spinning course is finished, automatically. Or, the preliminary drying step may be performed according to user&#39;s selection after a selected course is finished. The user can select to perform the preliminary drying step at the input unit  180 . 
     Thus, if the preliminary drying step is added to an end of the selected course, the preliminary drying step can be performed while the drum is rotating by inertia after the spinning course is finished. In this case, the drum  130  can rotate at a predetermined speed, for an example, 40 to 100 RPM. Though the drum  130  rotates at a rotation speed of the spinning course since the preliminary drying step is performed in the middle of the spinning course in the foregoing embodiment described with reference to  FIG. 2 , since the preliminary drying step is performed after finishing the spinning course in the embodiment described with reference to  FIG. 4 , the rotation speed of the drum  130  can be lower than the rotation speed of the spinning course. 
     In the meantime, if temperature control of the heater  125  provided to the laundry machine is possible, it is also possible that the heater  125  can heat the air while the heater  125  is kept turned on below a predetermined temperature at which the heater  125  is overheated. Even in a case the heater  125  is kept turned on below the predetermined temperature, it is preferable that the heater  125  is turned off periodically in a case the heater  125  is kept turned on more than a certain time period for preventing the heater  125  from overheating. 
     In the meantime, instead of rotating the drum  130  for generating the air flow in the preliminary drying step, a flow generating member may be provided at one side of the tub  120  adjacent to the heater  125  which can generate the air flow. It is preferable that the flow generating member is of a screw type that can be submerged in water taking that the washing water is held in the tub  120 . 
     Though the foregoing embodiment suggests heating the air with the heater which heats the washing water, the preliminary drying step of the present invention is not limited to the foregoing embodiment. For an example, since a laundry machine having a drying function is provided with a hot air supply unit in the laundry machine for supplying hot air to the inside of the tub, the preliminary drying step can be made by supplying the hot air by using the hot air supplying unit. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. 
     INDUSTRIAL APPLICABILITY 
     The preliminary drying step of the present invention permits to remove moisture from the washing objects more than a predetermined amount, thereby permitting drying the washing objects faster than drying the washing objects naturally, or with a laundry machine having a drying function. 
     Moreover, the laundry machine and the control method thereof of the present invention enable to remove moisture from the washing objects without providing heating means to the laundry machine additionally.