CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority to Korean Application No. 10-2019-0042785, filed on Apr. 12, 2019, the disclosure of which is incorporated by reference in its entirety.

BACKGROUND

Field

The present disclosure relates to a washing machine and control method thereof, and more particularly, to a washing machine capable of automatically providing the washing machine with various detergents.

Related Art

A washing machine is a device handling laundry through washing, dehydration and/or drying and the like. The washing machine is a device removing contamination of a laundry by using water and detergents.

Recently, there is a need to develop a device automatically mixing and providing various detergents according to various laundries, so technical features related therewith are under development.

During supplying various detergents, it is necessarily required to employ detecting function to let user refill detergent in case of lack of detergent in a cartridge.

U.S. Patent Publication No. 2010/0161143 A1 discloses detecting residual amount of detergent in the cartridge with a pair of sensors. However, in case of using a pair of sensors, there may be a problem that the sensor is electrified because the sensor is swayed by an external force even though lack of detergent, and a problem that the sensor is electrified because detergent is exposed to air so that the detergent is harden on the sensor. As the result of the foregoing, there may be a malfunction of the sensor detecting residual quantity of detergent.

SUMMARY

One object of the present disclosure is to provide a washing machine capable of precisely detecting a residual amount of detergent contained in a cartridge.

Another object of the present disclosure is to provide a washing machine capable of determining whether a cartridge is properly mounted or malfunctioned, or a cartridge sensor is malfunctioned or something.

Objects of the present disclosure should not be limited to the aforementioned objects and other unmentioned objects will be clearly understood by those skilled in the art from the following description.

In accordance with an embodiment of the present disclosure, the above and other objects can be accomplished by the provision of washing machine including a cabinet, a tub disposed in the cabinet so as to receive water, a drum rotatably disposed in the tub so as to accommodate a laundry and a detergent supply device disposed at the cabinet so as to supply detergent contained in a plurality of cartridges into the tub, the method including the steps of (a) detecting a first sensor value by a first two electrode sensors and a second sensor value by a second two electrode sensors having at least one electrode sensor which is placed at a higher position than the first two electrode sensors, the first and second two electrode sensors comprising at least three electrode sensors which are installed at at least one of the cartridges to detect an amount of detergent contained in a corresponding one of the plurality of cartridges, (b) comparing the first sensor value and the second sensor value with a first predetermined value, (c) passing a predetermined time when each of the first sensor value and the second sensor value is less than the first predetermined value, (d) redetecting the first sensor value and the second sensor value, and calculating a difference sensor value after the predetermined time is passed and (e) determining that detergent is filling to a height between the first two electrode sensors and the second two electrode sensors, when the difference value is greater than a second predetermined value after the predetermined time is passed.

The control method may further comprise determining that at least one of the electrode sensors is a malfunctioned, when the first sensor value is greater than the first predetermined value and the second sensor value is less than the first predetermined value.

The control method may further comprise determining that detergent is filling to a lower height than the first two electrode sensors, when each of the first sensor value and the second sensor value is greater than the first predetermined value.

The control method may further comprise determining that detergent is filling to a height between the first two electrode sensors and the second two electrode sensors, when the first sensor value is less than the first predetermined value and the second sensor value is greater than the first predetermined value.

The control method may further comprise determining that detergent is filling to a higher height than the second two electrode sensors, when the difference value is less than the second predetermined value.

The first and second two electrode sensors may comprise three electrode sensors, wherein the three electrode sensors include a first and second electrode sensors having a first height and a third electrode sensor having a height higher than the first height, wherein the first two electrode sensors comprises the first and second electrode sensors, and the second two electrode sensors comprises the first electrode sensor or the second electrode sensor and the third electrode sensor; and wherein the height between the first two electrode sensors and the second two electrode sensors is a height between the first or second electrode sensor and the third electrode sensor.

The control method may further comprise determining that detergent is filling to a lower height than the first two electrode sensors, when each of the first sensor value and the second sensor value is greater than the first predetermined value.

The control method may further comprise determining that detergent is filling to a height between the first two electrode sensors and the third electrode sensor, when the first sensor value is less than the first predetermined value and the second sensor value is greater than the first predetermined value.

The step (d) may further comprise determining that detergent is filling to a higher position than the at least one electrode sensor, when the difference value is less than the second predetermined value.

The washing machine may comprise a cabinet, a tub disposed in the cabinet so as to receive water, a drum rotatably disposed in the tub, the drum containing laundry, and a detergent supply device disposed at the cabinet to supply detergent into the tub, the detergent supply device comprising a plurality of cartridges containing detergent, a passage switching valve connecting to at least one of the plurality of cartridges, a pump connected to the at least one cartridge via the passage switching valve to pump detergent contained in the at least one cartridge to the tub and a passage guiding the detergent suctioned by the pump into the tub, wherein at least three electrode sensors are installed at each of the at least one of the plurality of cartridges, wherein at least one electrode sensor of the at least three electrode sensors has a different height from those of the other electrode sensors.

The detergent supply device may further comprise a housing accommodating the one of cartridges, wherein the electrode sensors are installed at a rear wall of the housing.

Each of the electrode sensors may comprise an electrode plate and a terminal connected to the electrode plate to transmit an electric signal.

An opening for the electrode plate may be formed at a rear surface of the at least one cartridge so that detergent contained in the at least one cartridge is contacted to the electrode plate.

The washing machine including the same according to the present disclosure provide at least the following effects.

First, the washing machine according to an exemplary embodiment of the present disclosure has an advantage of minimizing a misjudgment of an electrode sensor due to detergent hardened on the electrode sensor even in a case that a cartridge is not filled with enough detergent.

Second, the washing machine according to an exemplary embodiment of the present disclosure has an advantage of minimizing a misjudgment of an electrode sensor due to a inclined electrode sensor or sway of the electrode sensor even in a case that a cartridge is not filled with enough detergent.

Third, the washing machine according to an exemplary embodiment of the present disclosure has an advantage of determining whether an electrode sensor for detecting a residual amount of detergent is malfunctioned.

Fourth, the washing machine according to an exemplary embodiment of the present disclosure has an advantage of determining whether a cartridge is empty or unmounted without a need for installing an additional sensor.

It should be understood that advantageous effects according to the present disclosure are not limited to the effects set forth above and other advantageous effects of the present disclosure will be apparent from the detailed description of the present disclosure.

Details of other embodiments will be described in the detailed description with reference to the accompanying drawings.

