DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.

[0024] FIG. 1 shows a sectional view of a washing machine to which the present method of controlling a rinsing operation is applied.

[0025] The washing machine includes a water tub 2 which is positioned in the interior of a housing 1. A wash tub 3 is rotatably disposed in the water tub 2. A pulsator 4 is rotatably mounted on a bottom of the interior of the wash tub 3. A wash motor 5 is mounted beneath a peripheral portion of the bottom of the water tub 2, and rotates in forward and reverse directions. The wash motor 5 is connected to a clutch mechanism 8 via pulleys 6 and a belt 7.

[0026] The clutch mechanism 8 receives a rotating force of the wash motor 5 to rotate the pulsator 4 in the forward and reverse directions during washing and rinsing operations, and to rotate the wash tub 3 at a high speed in a forward direction during a spin-drying operation.

[0027] A water supply conduit 9 is installed in an upper portion of the housing 1 to be connected to an outside water pipe (not shown). A water supply valve 10 is disposed in the water supply conduit 9 to control a water supply.

[0028] A water discharge valve 11 is disposed under the water tub 2 to discharge the water contained in the water tub 2, and connected to a water discharge conduit 12.

[0029] FIG. 2 is a block diagram of an apparatus which controls a rinsing operation of the washing machine shown in FIG. 1.

[0030] The apparatus includes a function selecting switch 20, a temperature sensor 21, a water level detecting unit 22, a weight detecting unit 23, and a rotation number detecting unit 24 which are electrically connected to an input side of a control unit 30. The control unit 30 controls the overall operation of the washing machine. The function selecting switch 20 selects a desired washing function, such as a washing, rinsing or spin-drying function. The temperature sensor 21 senses a temperature of water supplied to the water tub 2. The water level detecting unit 22 detects a water level of the water tub 2. The weight detecting unit 23 detects a weight of laundry. The rotation number detecting unit 24 detects a rotation number of the wash motor 5.

[0031] In addition, a water supply valve drive unit 40, a water discharge valve drive unit 41, a display 42, and a washing motor drive unit 43 are electrically connected to an output side of the control unit 30. The water supply valve drive unit 40 selectively opens and closes the water supply valve 10. The water discharge valve drive unit 41 selectively opens and closes the water discharge valve 11. The display 42 displays various information including a current operating state of the washing machine. The washing motor drive unit 43 drives the wash motor 5.

[0032] Hereinafter, with reference to FIG S. 3A and 3B, a method of controlling the rinsing operation of the washing machine shown in FIG. 1 will be described.

[0033] FIG. 3A shows a flowchart illustrating the method of controlling the rising operation of the washing machine shown in FIG. 1.

[0034] With reference to FIGS. 1 and 2, the control unit 30 supplies wash water to the water tub 2 up to a water level preset by a user, and drives the wash motor 5 through the washing motor drive unit 43 in forward and reverse directions to rotate the pulsator 4 according to the kind and weight of laundry and the preset water level. Accordingly, the laundry is washed by water flows formed by the forward and reverse rotations of the pulsator 4 in a washing operation 100.

[0035] Where the washing operation 100 is completed, the control unit 30 performs washing water discharging, spin-drying and rinsing processes for a preset rinsing time, for example, 13 minutes.

[0036] That is, the control unit 30 controls the water discharge drive unit 41 so as to open the water discharge valve 41 to discharge the used wash water from the water tub 2 to the outside. In addition, the control unit 30 rotates the wash tub 3 at a high speed to remove the wash water absorbed into the laundry, and controls the water supply valve drive unit 40 so as to open the water supply valve 10 to supply fresh wash water to the water tub 2. Furthermore, the control unit 30 controls the washing motor drive unit 43 so as to rotate the wash motor 5 in forward and reverse directions to rotate the pulsator 4 in forward and reverse directions, thereby performing a rinsing process 101 of the rinsing operation.

[0037] Thereafter, the control unit 30 repeatedly performs the rinsing process for a preset number of times, for example, four times, in processes 102, 103, and 104.

[0038] Where the last rinsing process, for example, the rinsing process 104 is performed, the control unit 30 performs a wrinkle preventing rinsing process 105 by disentangling the laundry so as to have a fabric of the laundry absorb wash water and prevent wrinkles from forming in the laundry.

[0039] After performing the wrinkle preventing process 105, the control unit 30 completely discharges the wash water from the water tub 2 and spin-dries the laundry by rotating the wash tub 3 at a high-rotation speed to remove the wash water absorbed into the laundry in a spin-drying operation 106.

[0040] After performing the spin-drying operation 106, the control unit 30 controls the washing motor drive unit 43 so as to stop the wash motor 5 to end an overall washing procedure.

[0041] FIG. 3B is a flowchart showing the wrinkle preventing rinsing process 105 of FIG. 3A.

[0042] With reference to FIGS. 1 and 2, where the wrinkle preventing rinsing process is started, the control unit 30 performs washing water discharging, spin-drying and rinsing sub-processes for a set rinsing time.

[0043] That is, the control unit 30 controls the water discharging valve drive unit 41 so as to open the water discharging valve 11 to discharge the used wash water from the water tub 2 to the outside in a washing water discharging sub-process 200.

[0044] Where the wash water is discharged to the outside, the control unit 30 spin-dries the laundry by rotating the wash tub 3 at a high speed to remove the wash water absorbed into the laundry in a spin-drying sub-process 201.

[0045] Where the laundry is spin-dried, the control unit 30 controls the water supply drive unit 40 so as to open the water supply valve 10 to supply wash water to the water tub 2 to a preset water level in a washing water supplying sub-process 202.

[0046] Where the supplying of the wash water is completed, the control unit 30 controls the washing motor drive unit 43 so as to drive the wash motor 5 to rotate the pulsator 4 in forward and reverse directions for a first preset time (for example, one minute) in a sub-process 203.

[0047] Where the first preset time elapses, the control unit 30 stops the rotation of the pulsator 4 for a second preset time (for example, four minutes) which is set to be longer than the first preset time in a sub-process 204. As a result, the laundry is disentangled by wrinkle preventing water flows formed by a starting and stopping operations of the pulsator 4. Accordingly, the formation of wrinkles in the laundry is minimized.

[0048] Where the second preset time elapses, the control unit 30 may repeat the above-described sub-processes 203 and 204 once more in sub-processes 205 and 206. Accordingly, the entanglement of the laundry is further eliminated, and the formation of the wrinkles in the laundry is further minimized.

[0049] FIG. 4 shows a timing chart for the pulsator 4 at a general rinsing process and a wrinkle preventing rinsing process of the present invention.

[0050] As depicted in FIG. 4, a rinsing time T for the wrinkle preventing rinsing process is set to be longer than a rinsing time To for the general rinsing process (such as rinsing 1, rinsing 2, rinsing 3 and rinsing 4 of FIG. 3A).

[0051] During the wrinkle preventing rinsing process, the pulsator 4 is driven for a pulsator driving time T₁, and the pulsator is stopped for a pulsator stopping time T₂ which is set to be longer than the pulsator driving time T₁, thereby disentangling the laundry and allowing a fabric of the laundry to absorb the wash water. This, in effect, prevents the wrinkles from forming in the laundry.

[0052] As described above, the present invention provides a method of controlling a rinsing operation of a washing machine, wherein the method allows a spin-drying operation to be performed after an entanglement of laundry is eliminated, so as to minimize the formation of wrinkles in the laundry.

[0053] Although a few embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.