Washing machine and method for controlling the same

Abstract

A washing machine having a steam generating device for directly heating wash water to generate optimum steam, and a method for controlling the same are provided. The method includes sensing a temperature of the steam generating device; controlling water supply means according to the temperature of the steam generating device such that wash water is supplied to the steam generating device; and controlling a quantity of wash water supplied from the water supply means. Further, the steam is supplied so as to rapidly soak laundry, thereby shortening overall washing time, and reducing energy consumption. Also, the steam is sprayed onto the laundry to provide sterilizing effects. Soaking effects of the laundry are improved, as well, so as to increase washing efficiency and eliminate wrinkling.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Korean Patent Application No. 2004-94773, filed Nov. 18, 2004, in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Apparatuses and methods consistent with the present invention relates to a washing machine with a steam generating device for generating steam directly from wash water, and more particularly, to a washing machine for rapidly heating supplied wash water to provide optimum steam and a method for controlling the same.

2. Description of the Related Art

Generally, a drum washing machine is an apparatus for washing laundry by means of force for elevating and then dropping the laundry in a cylindrical drum when the drum is rotated. Compared to a conventional pulsator washing machine, the drum washing machine has a long washing time, but keeps damage to the laundry to a minimum and consumes a small amount of wash water. Thus, demand for drum washing machines is increasing.

Japanese Patent Laid-open Publication No. 2001-149685 discloses a drum washing machine with a device for heating wash water to wash the laundry.

The washing machine disclosed by the above Patent comprises a tub containing wash water, a drum rotatably installed in the tub and rotated by rotary force supplied from a driving motor, and a heater installed below the tub for heating the wash water contained in the tub.

When the washing machine performs a washing operation under the condition that the wash water and the laundry are put into the tub, the laundry together with the wash water is elevated along the inner circumferential surface of the drum and dropped by the rotation of the drum in the tub, thereby washing the laundry. Here, since the wash water is heated by the heater, the washing efficiency of the washing machine is increased.

Since a large amount of wash water contained in the tub is heated by the heater installed below the tub after the wash water is supplied, the above conventional washing machine is disadvantageous in that it takes a long time to heat the wash water to a temperature required to wash the laundry, thereby requiring an increased overall washing time.

SUMMARY OF THE INVENTION

Therefore, one aspect of the present invention is to provide a washing machine and a method for controlling the same, in which supplied wash water is rapidly heated to supply optimum steam to the inside of a tub so that a washing time is shortened, the steam of a high temperature is directly sprayed onto laundry to have sterilizing and soaking effects so that washing performance is improved, and a consumption rate of energy for heating the wash water is reduced.

Another aspect of the present invention is to provide a washing machine and a method for controlling the same, in which steam of a high temperature is sprayed onto laundry to increase the temperature of the laundry in a short period of time, thereby improving detergency to increase washing effects and eliminating wrinkling of the laundry.

In accordance with one aspect, the present invention provides a method for controlling a washing machine, which heats supplied wash water using a steam generating device to generate steam, comprising: sensing a temperature of the steam generating device; controlling water supply means for supplying the wash water to the steam generating device according to the sensed temperature of the steam generating device; and performing a steam operation for controlling the steam generated from the steam generating device according to a time taken to control the water supply means.

Additionally, the water supply means may be controlled such that the wash water is supplied to the steam generating device when the temperature of the steam generating device is more than a predetermined reference temperature; and the water supply means may be controlled such that the wash water supplied to the steam generating device is cut off when the temperature of the steam generating device is not more than a predetermined reference temperature.

Further, the wash water supplied to the steam generating device may be cut off to stop the generation of the steam, when a time during which the water supply means is turned on to supply water exceeds a predetermined water supply time; and the wash water may be supplied to the steam generating device to generate the steam, when a time during which the water supply means is turned off to stop supplying water exceeds a predetermined water supply stop time.

In accordance with another aspect, the present invention provides a method for controlling a washing machine, which heats supplied wash water using a steam generating device to generate steam, comprising: preheating the steam generating device before the wash water is supplied to the steam generating device; sensing a temperature of the preheated steam generating device; controlling water supply means for supplying the wash water to the steam generating device by comparing the sensed temperature of the steam generating device to a predetermined reference temperature; and controlling the generation of the steam by comparing a time, taken to control the water supply means, to a predetermined water supply time and a predetermined water supply stop time.

Also, the wash water supplied to the steam generating device may be cut off to stop the generation of the steam, when a time during the turning on of the water supply means exceeds the predetermined water supply time; and the wash water may be supplied to the steam generating device to generate the steam, when a time during the turning off of the water supply means exceeds the predetermined water supply stop time.

In accordance with yet another aspect, the present invention provides a washing machine having a steam generating device for heating supplied wash water to generate steam comprising: a temperature sensing unit for sensing a temperature of the steam generating device; water supply means for supplying the wash water to the steam generating device; and a control unit for controlling the water supply means such that the steam generated from the steam generating device is controlled according to the temperature of the steam generating device.

Additionally, the control unit may control the steam generating device such that the steam generating device is preheated before the wash water is supplied to the steam generating device; and the control unit may compare a time, taken to control the water supply means to a predetermined water supply time and a predetermined water supply stop time, and controls the generation of the steam according to the result of the comparison.

Further, the water supply means may be a steam valve capable of being turned on and off so as to control the wash water supplied to the steam generating device according to control of the control unit.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects of the invention will become apparent and more readily appreciated from the following description of the exemplary embodiments, taken in conjunction with the accompanying drawings in which:

FIG. 1 is a longitudinal sectional view of a washing machine according to an exemplary embodiment of the present invention;

FIG. 2 is a block diagram of a washing machine in accordance with an exemplary embodiment of the present invention;

FIG. 3 is a flow chart illustrating a method for controlling the washing machine according to an exemplary embodiment of the present invention; and

FIG. 4 is a flow chart illustrating a detailed process for heating wash water and laundry using steam in the method of FIG. 3.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Reference will now be made in detail to illustrative, non-limiting embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The exemplary embodiments are described below to explain aspects of the present invention by referring to the annexed drawings.

FIG. 1 is a longitudinal sectional view of a washing machine according to an exemplary embodiment of the present invention.

In FIG. 1, the washing machine comprises a drum-type tub 11 installed in a main body 10 for containing wash water, and a drum 12 rotatably installed in the tub 11.

The tub 11 meets the installation surface of the washing machine at a designated angle (α) such that a front surface 11a of the tub 11, through which an inlet 11b is formed, has a level higher than that of a rear surface 11c of the tub 11, and the drum 12 installed in the tub 11 is inclined in the same manner as the tub 11 such that a front surface 12a of the drum 12, through which an inlet 12b is formed, has a level higher than that of a rear surface 12c of the drum 12.

Thus, the front surface 12a of the drum 12, through which the inlet 12b is formed, turns upwards, and a rotational central line A of the drum 12 meets the installation surface of the washing machine at the designated angle (a). Here, a rotary shaft 13 connected to the center of the rear surface 12c of the drum 12 is rotatably supported to the center of the rear surface 11c of the tub 11, thereby allowing the drum 12 to be rotated in the tub 11.

A plurality of through holes 12d are formed through the circumferential surface of the drum 12. Also, a plurality of drain holes 12e, for discharging wash water in the drum 12 when the drum 12 is rotated at a high speed, are formed through the outer portion of the front surface 12a of the drum 12. Further, a plurality of lifters 14, for elevating and dropping laundry when the drum 12 is rotated, are installed along the inner surface of the drum 12.

A motor 15, serving as a driving device for rotating the rotary shaft 13 connected to the drum 12, is installed at the outer portion of the rear surface 11c of the tub 11. The motor 15 includes a stator 15a fixed to the rear surface 11c of the tub 11, a rotor 15b rotatably disposed outside the stator 15a, and a driving plate 15c for connecting the rotor 15b and the rotary shaft 13.

An inlet 16 for allowing laundry to be put into or taken out of the drum 12 is formed through a position of the front surface of the main body 10 corresponding to the positions of the inlet 12b of the drum 12 and the inlet 11b of the tub 11. A door 17 for opening and closing the inlet 16 is installed at the inlet 16.

A detergent supply device 18 for supplying a detergent to the inside of the tub 11, a steam generating device 30 for generating optimum steam to the inside of the tub 11, and a water supply device 20 for supplying water to the tub 11 and the steam generating device 30 are installed above the tub 11.

The detergent supply device 18 includes a space for containing the detergent therein, and is installed close to the front surface of the main body 10 so that a user can easily put the detergent into the detergent supply device 18.

The water supply device 20 includes a water supply pipe 21 for supplying water to the inside of the tub 11, and a water supply valve 22 installed in the water supply pipe 21 for controlling the supply of the water to the inside of the water supply pipe 21. Here, the water supply pipe 21 is connected to the detergent supply device 18 so that the water supplied from the outside is supplied to the detergent supply device 18. A connection pipe 23 is installed between the detergent supply device 18 and the tub 11 such that the water having passed through the detergent supply device 18 is supplied to the tub 11. The connection pipe 23 causes water, which is supplied to the inside of the tub 11, to pass through the detergent supply device 18, thereby allowing the detergent contained in the detergent supply device 18 to be dissolved in the water and then supplied to the inside of the tub 11.

The water supply device 20 further includes a steaming water supply pipe 24 for supplying water to the steam generating device 30 as well as to the detergent supply device 18, and a steam valve 25 installed in the steaming water supply pipe 24 for controlling the supply of the water to the steam generating device 30.

Although the water supply device 20 includes the water supply valve 22 and the steam valve 25, which are separately installed as described above, the present invention is not limited thereto. For instance, the water supply device 20 may include an integrated assembly of the water supply valve 22 and the steam valve 25 using a conventional electric three-way or four-way valve.

The steam generating device 30 includes a U-shaped steam heater 32 installed therein for rapidly heating water passing therethrough to generate steam at a high temperature of at least 100° C., a temperature sensor 34 installed at one side of the steam generating device 30 for sensing the temperature of the steam generating device 30, a steam supply pipe 36 extended from the steam generating device 30 to the tub 11, and a discharge nozzle 38 installed at an outlet of the steam supply pipe 36.

Although the steam heater 32 is installed in the steam generating device 30, as described above, the present invention is not limited thereto. For example, the steam heater 32 may be an external heater having a structure contacting the external surface of an upper or lower portion of the steam generating device 30 or surrounding the external circumferential surface of the steam generating device 30.

A heater 40 for heating the wash water supplied to the inside of the tub 11 is installed in the lower portion of the tub 11. A heater receiving portion 41 for receiving the heater 40 and collecting a designated quantity of the wash water is formed in the lower surface of the tub 11 such that the heater receiving portion 41 has a downwardly protruded structure. This structure of the heater receiving portion 41 allows the heater 40 to be soaked in the wash water collected in the heater receiving portion 41. The heater 40 is received by the heater receiving portion 41, thereby being rotated without interfering with the drum 12.

The washing machine of the present invention further comprises a drain device 50 for discharging the wash water of the inside of the tub 11, and a wash water circulating device 60 for supplying the wash water in the tub 11, heated by the heater 40, to the inside of the drum 12.

The drain device 50 includes a first drain pipe 51 connected to a drain hole 42 formed through the heater receiving portion 41 at the lower surface of the tub 11 for guiding the water in the tub 11 to the outside, a drain pump 52 installed in the first drain pipe 51, and a second drain pipe 53 connected to an outlet of the drain pump 52.

The wash water circulation device 60 includes a channel change valve 61 installed in the second drain pipe 53 connected to the outlet of the drain pump 52, a wash water circulating pipe 62 extended from the channel change valve 61 to the inlet 12b of the drum 12, and a spray nozzle 63 installed at an outlet of the wash water circulating pipe 62. Here, the channel change valve 61 serves to change a channel such that the wash water at the outlet of the drain pump 52 is discharged to the outside or flows to the wash water circulating pipe 62, and is generally an electric three-way valve.

Hereinafter, the operation of the above-described washing machine will be described.

When the washing machine is operated under the condition that laundry is put into the drum 12 and the detergent is put into the detergent supply device 18, the water supply valve 22 of the water supply device 20 is opened so that wash water is supplied to the detergent supply device 18.

Here, the detergent of the detergent supply device 18 is dissolved in the wash water supplied to the tub 11 through the detergent supply device 18, and is then supplied to the inside of the tub 11. The washing machine according to an exemplary embodiment of the present invention, which comprises the wash water circulating device 60, does not need to supply the wash water to a level of the inside of the drum 12 for soaking the laundry in the drum 12, thereby reducing the quantity of wash water required as compared to the conventional washing machine.

After the supply of the wash water to the inside of the drum 12 is completed, the heater 40 is operated to heat the wash water filling the tub 11. Since the washing machine according to an exemplary embodiment of the present invention requires a small quantity of the supplied wash water compared to the conventional washing machine, the temperature of the wash water heated by the heater 40 is rapidly increased, thereby shortening an overall washing time and reducing the quantity of energy consumed to heat the wash water.

After the wash water is heated by the heater 40 to a temperature required to wash the laundry, the channel change valve 61 of the wash water circulating device 60 is operated. Then, the channel is formed such that the outlet of the drain pump 52 communicates with the wash water circulating pipe 62, and the wash water at the lower portion of the tub 11 is supplied to the inside of the drum 12 through the first drain pipe 51 and the wash water circulating pipe 62 by the operation of the drain pump 52.

Here, since the wash water supplied to the inside of the drum 12 is sprayed onto the laundry through the spray nozzle 63, the wash water uniformly soaks the laundry. The drum 12 is rotated at a low speed by the operation of the motor 15, thereby achieving a washing operation.

During the washing operation, when the level of the wash water contained in the drum 12 is more than the height of the drain holes 12e, the wash water flows into the tub 11 through the drain holes 12e. The wash water is circulated such that the wash water contained in the tub 11 is supplied again to the inside of the drum 12 through the first drain pipe 51 and the wash water circulating pipe 62 by the operation of the drain pump 52.

When a user selects a steam course, the steam valve 25 is opened so that the wash water is supplied to the steam generating device 30 through the steaming water supply pipe 24, and the wash water supplied to the steam generating device 30 is rapidly heated by the steam heater 32 to generate steam at a high temperature of at least 100° C.

The steam at high temperature is supplied to the inside of the tub 11 through the steam supply pipe 36 and the discharge nozzle 38, and serves to additionally heat the wash water and the laundry in the tub 11, which were previously heated by the heater 40.

When temperatures of the wash water and the laundry are increased to a designated temperature by the circulation of the wash water and the supply of the steam, the supply of the steam is stopped and the drum 12 is rotated at a low speed by the operation of the motor 15, thereby achieving the washing operation.

After the washing operation is completed, a rinsing operation, in which dehydration and repeated supply of wash water occurs, is performed. During the rinsing operation, the water supply valve 22 is opened so that water is supplied to the inside of the tub 11 through the water supply pipe 21. The channel change valve 61 is opened so that the outlet of the drain pump 52 is opened toward the external drain pipe 53, and the drain pump 52 is operated, thereby discharging the water in the tub 11. When a final dehydrating operation is performed after the rinsing operation, the drain pump 52 is operated under the condition that the outlet of the drain pump 52 is opened toward the external drain pipe 53, and the drum 12 is rotated at a high speed for a designated time, thereby dehydrating the laundry in the tub 11.

FIG. 2 is a block diagram of a washing machine in accordance with an exemplary embodiment of the present invention. The washing machine comprises a signal input unit 100, a water level sensing unit 110, a temperature sensing unit 120, a control unit 130, and an operating unit 140.

The signal input unit 100 allows a user to input selected operating data, such as a washing course, a washing temperature, a dehydrating rotation speed, and an additional rinsing operation. The water level sensing unit 110 senses the level of the wash water supplied to the inside of the tub 11. The temperature sensing unit 120 includes a temperature sensor 34 for sensing the temperature of the wash water supplied to the tub 11 and the temperature of the steam generating device 30.

The control unit 130 is a microcomputer for controlling the washing machine according to the operating data inputted from the signal input unit 100. The control unit 130 controls operations of the steam valve 25 and the steam heater 32 based on the temperature sensed by the temperature sensing unit 120, thereby causing the steam generating device 30 to generate a large quantity of steam at a high temperature of at least 100° C.

The operating unit 140 operates the motor 15, the water supply valve 22, the steam valve 25, the steam heater 32, the heater 40, the drain pump 52, and the channel change valve 61 based on an operation control signal of the control unit 130.

Hereinafter, the operation and effects of the above-described washing machine and a method for controlling the same will be described in detail.

FIG. 3 is a flow chart illustrating the method for controlling the washing machine of the present invention. In FIG. 3, “S” denotes an operation.

The method for controlling the washing machine of the present invention comprises operations (S100˜S200) of supplying wash water to the inside of the tub 11 according to a steam washing course selected by a user; operations (S300˜S400) of heating the wash water supplied to the inside of the tub 11 using the heater 40; operations (S500˜S600) of heating the wash water and laundry in the tub 11, heated by the heater 40, by spraying steam of a high temperature of at least 100° C. thereonto; an operation (S700) of performing a washing operation according to a washing course selected by the user after the wash water and the laundry is heated by the heater 40 and the heater; and an operation (S800) of performing rinsing, dehydrating, and drying operations after the washing operation is completed.

Now, the method for controlling the above-described washing machine will be described in more detail.

When the user selects operating data, such as a washing course (for example, a steam washing course), a washing temperature, a dehydrating rotation speed, and an additional rinsing operation, the operating data selected by the user are inputted to the control unit 130 through the signal input unit 100 (S100).

Then, the control unit 130 turns the water supply valve 22 on so that wash water is supplied to the detergent supply device 18, and a detergent in the detergent supply device 18 is dissolved in the wash water supplied to the inside of the tub 11 through the detergent supply device 18, and is then supplied to the tub 11 (S200).

Here, the method for controlling the washing machine according to an exemplary embodiment of the present invention, which comprises the wash water circulating device 60, does not need to supply the wash water to a level of the inside of the drum 12 for soaking the laundry in the drum 12. Therefore, the quantity of wash water required is reduced as compared to conventional washing machines.

After a designated quantity of the wash water is supplied to the inside of the tub 11 through the water supply pipe 21, the control unit 130 turns the water supply valve 22 off so that the supply of the wash water to the water supply pipe 21 is stopped.

After the supply of the wash water is completed, the heater 40 is operated by the controlling operation of the control unit 130, thereby heating the wash water in the tub 11 (S300). Since the method for controlling the washing machine according to an exemplary embodiment of the present invention requires a small quantity of the supplied wash water compared to the conventional method, the temperature of the wash water heated by the heater 40 is rapidly increased, thereby shortening an overall washing time and reducing the quantity of energy consumed to heat the wash water.

An operating time of the heater 40 is checked, and it is determined whether or not a designated time (T1; a time taken to heat the wash water to a temperature required to perform a washing operation using the heater 40) elapses (S400). When it is determined that the designated time (T1) has elapsed, the operation of the heater 40 is stopped.

Thereafter, the control unit 130 controls the steam valve 25 so that the wash water is supplied to the steam generating device 30 through the steaming water supply pipe 24, and the wash water supplied to the steam generating device 30 is rapidly heated by the steam heater 32 to generate steam at a high temperature of at least 100° C.

The steam at high temperature is supplied to the inside of the tub 11 through the steam supply pipe 36 and the discharge nozzle 38, and serves to additionally heat the wash water and the laundry in the tub 11, which were previously heated by the heater 40 (S500).

Since the method for controlling the washing machine according to exemplary embodiments of the present invention requires a small quantity of the supplied wash water due to the use of the wash water circulating device 60 and supplies a large quantity of the steam at a high temperature of at least 100° C. to the inside of the tub 11 through the steam generating device 30, the method rapidly increases the temperature of the wash water compared to the conventional method, in which the wash water is heated only by the heater 40 installed in the lower portion of the tub 11, thereby remarkably shortening an overall washing time and reducing the quantity of energy consumed to heat the wash water.

Further, since the method for controlling the washing machine according to exemplary embodiments of the present invention sprays the steam at high temperature onto the laundry, which is sufficiently soaked by the wash water, the temperature of the laundry is rapidly increased, thereby shortening the washing time and improving the detergency to increase the washing effects of the washing machine.

A steam supply time of the steam generating device 30 is checked, and it is determined whether or not a designated time (T2; overall operating time of the steam generating device 30 from a point of the time when the steam heater 32 is preheated, approximately 6˜10 minutes) elapses (S600). When it is determined that the designated time (T2) has elapsed, the operation of the steam heater 32 is stopped, and the drum 12 is rotated at a low speed by the operation of the motor 15 so that washing operation is performed according to the selected washing course (S700).

When the washing operation is completed, at least one or all of rinsing, dehydrating, and drying operations is performed according to the selected operating data, and the steam washing course is terminated (S800).

Hereinafter, with reference to FIG. 4, a process for heating the wash water and the laundry using the steam in the method for controlling the washing machine as shown in FIG. 3 will be described in more detail.

In order to supply a large quantity of the steam at a high temperature to the inside of the tub 11, the control unit 130 preheats the steam heater 32 installed in the steam generating device 30 (S510).

The steam heater 32 is preheated so that the steam generating device 30, at an initial operating state, supplies pure steam, which is not mixed with water at room temperature (23˜24° C.), to the inside of the tub 11.

The temperature sensing unit 120 senses a temperature (S_T) of the steam generating device 30 due to the preheating of the steam heater 32, and outputs the sensed temperature (S_T) to the control unit 130 (S520). The control unit 130 determines whether or not the temperature (S_T) of the steam generating device 30 inputted from the temperature sensing unit 120 is more than a predetermined reference temperature (S_TS; the lowermost temperature for heating the steam heater 32 to generate steam, approximately 100° C.) (S530).

As the result of the above comparison, when it is determined that the temperature (S_T) of the steam generating device 30 is more than the predetermined reference temperature (S_TS), the control unit 130 turns the steam valve 25 on (S540).

When the steam valve 25 is turned on, the wash water is supplied to the steam generating device 30 through the steaming water supply pipe 24, and the wash water supplied to the steam generating device 30 is rapidly heated by the steam heater 32 to generate steam at a high temperature of at least 100° C.

The steam of the high temperature is supplied to the inside of the tub 11 through the steam supply pipe 36 and the discharge nozzle 38, and additionally heats the wash water and the laundry in the tub 11, which were previously heated by the heater 40.

Thereafter, when a designated time (T3; a time taken to generate steam at a high temperature of at least 100° C., approximately 2 seconds) from the turning on of the steam valve 25 elapses (S550), the control unit 130 turns the steam valve 25 off (S560).

A time during the turning off of the steam valve 25 is checked, and when a designated time (T4; a time taken to increase the temperature of the steam generating device 30 to a high temperature of at least 100° C., approximately 10 seconds) has elapsed (S570), the control unit 130 turns the steam valve 25 on again until the designated time (T2) elapses, thereby repeating the above process.

As apparent from the above description, aspects of the present invention provide a washing machine and a method for controlling the same, in which supplied wash water is rapidly heated in a short period of time so that a large quantity of steam at a high temperature of at least 100° C. is supplied to the inside of a tub so as to rapidly increase the temperature of the wash water, thereby shortening an overall washing time and reducing a consumption rate of energy for heating the wash water.

Further, since the steam at the high temperature is sprayed onto laundry, which is sufficiently soaked by the wash water so as to rapidly increase the temperature of the laundry, the washing machine and the method for controlling the same according to aspects of the present invention are advantageous in that the overall washing time is shortened and sterilizing effects are improved. Moreover, the washing machine and the method for controlling the same according to aspects of the present invention increase soaking effects of the laundry, thereby increasing washing efficiency, reducing the quantity of energy consumed to perform the washing operation, and eliminating wrinkling of the laundry as a result of the use of steam.

Although exemplary embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made to the exemplary embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.

Claims

1. A method for controlling a washing machine, which heats supplied wash water using a steam generating device to generate steam, comprising:

sensing a temperature of the steam generating device;

controlling water supply means for supplying wash water to the steam generating device according to the sensed temperature of the steam generating device; and

performing a steam operation for controlling the steam generated from the steam generating device according to a time taken to control the water supply means.

2. The method as set forth in claim 1,

wherein the water supply means is controlled such that the wash water is supplied to the steam generating device when the temperature of the steam generating device is more than a predetermined reference temperature.

3. The method as set forth in claim 1,

wherein the water supply means is controlled such that the wash water supplied to the steam generating device is cut off when the temperature of the steam generating device is not more than a predetermined reference temperature.

4. The method as set forth in claim 1,

wherein the wash water supplied to the steam generating device is cut off to stop generation of the steam, when a time during which the water supply means is turned on to supply water exceeds a predetermined water supply time.

5. The method as set forth in claim 1,

wherein the wash water is supplied to the steam generating device to generate the steam, when a time during which the water supply means is turned off to stop supplying water exceeds a predetermined water supply stop time.

6. A method for controlling a washing machine, which heats supplied wash water using a steam generating device to generate steam, comprising:

preheating the steam generating device before wash water is supplied to the steam generating device;

sensing a temperature of the preheated steam generating device;

controlling water supply means for supplying the wash water to the steam generating device by comparing the sensed temperature of the steam generating device to a predetermined reference temperature; and

controlling the generation of the steam by comparing a time, taken to control the water supply means, to a predetermined water supply time and a predetermined water supply stop time.

7. The method as set forth in claim 6,

wherein the wash water supplied to the steam generating device is cut off to stop the generation of the steam, when a time during which the water supply means is turned on to supply water exceeds the predetermined water supply time.

8. The method as set forth in claim 6,

wherein the wash water is supplied to the steam generating device to generate the steam, when a time during which the water supply means is turned off to stop supplying water exceeds the predetermined water supply stop time.

9. A washing machine having a steam generating device for heating supplied wash water to generate steam comprising:

a temperature sensing unit for sensing a temperature of the steam generating device;

water supply means for supplying wash water to the steam generating device; and

a control unit for controlling the water supply means such that the steam generated from the steam generating device is controlled according to the temperature of the steam generating device.

10. The washing machine as set forth in claim 9,

wherein the control unit controls the steam generating device such that the steam generating device is preheated before the wash water is supplied to the steam generating device.

11. The washing machine as set forth in claim 9,

wherein the control unit compares a time, taken to control the water supply means to a predetermined water supply time and a predetermined water supply stop time, and controls the generation of the steam according to the result of the comparison.

12. The washing machine as set forth in claim 9,

wherein the water supply means is a steam valve capable of being turned on and off so as to control the wash water supplied to the steam generating device according to control of the control unit.