Patent Description:
A dishwasher is an appliance that removes dirt such as food waste or the like from dishes, cookware, etc. (hereinafter referred to as an "object to be washed") using a detergent and wash water.

Such a dishwasher typically includes a tub defining a washing compartment, a dish rack provided in the tub, in which an object to be washed is accommodated, a spray arm for spraying wash water toward the dish rack, a sump for storing wash water and supplying the wash water to the spray arm, and a filter for removing foreign substances from the wash water inside the sump.

In the dishwasher having the above construction, the wash water stored in the sump is sprayed toward an object to be washed through the spray arm, and the sprayed wash water is collected in the sump. The collected wash water passes through the filter so that foreign substances present in the wash water are removed therefrom, and the filtered wash water is again sprayed toward the object to be washed through the spray arm. Thereafter, all of the wash water that is present in the sump is discharged therefrom. At this time, the foreign substances collected in the filter may also be discharged along with the wash water.

In the above-described dishwasher, a constant amount of wash water circulates and is again sprayed toward an object to be washed. However, if foreign substances are not completely removed from wash water, an object to be washed that has already been completely washed may be recontaminated.

Further, foreign substances accumulated on the outer circumferential surface of the filter are not discharged along with wash water and adhere to the filter, which may deteriorate the performance of the filter.

<CIT> shows a dishwasher which incorporates a primary filter cleaning system for removing food debris from circulated wash water. The dishwasher having a sump formed in the floor of the dishwasher and a wash pump having an inlet in communication with the sump. A collection chamber is formed in the bottom of the sump and comprises at least one wall having filter media. A sprayer is disposed within the collection chamber and is in fluid communication with the pump. The sprayer has at least one nozzle aligned for spray contact with the filter media. When water is pumped from the sump to sprayer, the water is sprayed across the filter media to remove any debris from the filter media.

<CIT> shows a dishwasher with a washing tube and a receptable which is located at the lower portion of the washing tube having a hollow cylindrical microfilter that is placed at its mid. Inside the microfilter a sprayer is installed that supplies water from a pump to the inner surface of the microfilter to clean the microfilter.

An object of the present invention is to provide a dishwasher capable of diverting some or all of wash water that is supplied to a spray arm to the interior of a filter.

Another object of the present invention is to provide a method of removing foreign substances from wash water that is supplied to a spray arm using the above dishwasher.

A further object of the present invention is to provide a method of discharging foreign substances from a sump along with wash water using the above dishwasher.

A further object of the present invention is to provide a method of removing foreign substances accumulated on the filter using the above dishwasher.

The objects are solved by the method and the subject-matter of the independent claims.

To achieve the object and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a dishwasher includes a tub configured to accommodate an object to be washed, a spray arm rotatably provided inside the tub, the spray arm being configured to spray wash water toward the object to be washed, a sump configured to store wash water and to collect wash water sprayed into the tub therein, a filter separably mounted to the sump, the filter being configured to remove foreign substances from wash water, a wash pump configured to supply wash water stored in the sump to the spray arm, a supply passage configured to guide wash water, supplied by the wash pump, to the spray arm, and a circulation passage configured to divert at least a portion of wash water that is supplied to the spray arm by the wash pump to the sump. The circulation passage supplies wash water to a interior of the filter. The dishwasher further comprises a sensor for measuring the contamination of wash water mounted in the sump to control the amount of wash water that is diverted depending on the degree of contamination.

The filter may have an open bottom. The sump may include a filter support portion configured to support the bottom of the filter, a lower storage portion disposed under the filter support portion, the lower storage portion communicating with the interior of the filter through the open bottom of the filter, and an upper storage portion disposed on the filter support portion, the upper storage portion being separated from the lower storage portion by the filter support portion and being in contact with the outer surface of the filter.

The circulation passage may be connected to the lower storage portion.

The wash pump may be connected to the upper storage portion.

The dishwasher may further include a drain unit connected to the lower storage portion, the drain unit being configured to discharge wash water stored in the sump therefrom.

The dishwasher may further include a supply passage configured to guide wash water, supplied by the wash pump, to the spray arm. The circulation passage may be branched from the supply passage.

The dishwasher may further include a supply passage configured to guide wash water, supplied by the wash pump, to the spray arm, and a flow-switching unit configured to selectively open or close the supply passage and the circulation passage.

The flow-switching unit may include a flow-switching plate having therein at least one opening for opening the supply passage and the circulation passage, and a flow-switching motor configured to rotate the flow-switching plate.

The supply passage and the circulation passage may be opened simultaneously or selectively depending on rotation of the flow-switching plate.

The flow-switching unit may be a valve configured to selectively open the supply passage and the circulation passage.

The sump may further include a sump cover configured to separate the upper storage portion from the tub, the sump cover having therein a plurality of collection holes for collecting wash water sprayed into the tub therein.

The filter may include a mesh member extending into the sump through the sump cover and seated on the filter support portion, the mesh member being configured to remove foreign substances from wash water, and a core member covering the top of the mesh member, the core member being configured to remove foreign substances from wash water that flows to the mesh member from the region above the sump cover.

The filter may further include at least one support rib for supporting the mesh member so that the shape of the mesh member is maintained constant.

The filter may have an open bottom and may extend to the bottom surface of the sump.

The circulation passage may penetrate the bottom surface of the sump and may communicate with the interior of the filter.

The dishwasher may further include a drain unit for discharging wash water stored in the sump therefrom. The drain unit may penetrate the bottom surface of the sump and may communicate with the interior of the filter.

In another aspect of the present invention, there is provided a method of controlling a dishwasher comprising a tub for accommodating dishes, a spray arm for spraying wash water toward the dishes, a sump for storing wash water, a filter provided inside the sump in order to remove foreign substances from wash water, and a wash pump for supplying wash water stored in the sump to the spray arm.

The method comprises washing the dishes, the washing including supplying wash water to the spray arm and diverting at least a portion of wash water that is supplied to the spray arm to the interior of the filter, collecting foreign substances present in wash water in the interior of the filter by diverting all of wash water that is introduced into the wash pump to the interior of the filter, the collecting being performed after the washing is completed, and discharging foreign substances collected in the interior of the filter outside along with wash water.

The wash water supplied to the interior of the filter may pass through the filter due to the operation of the wash pump.

The washing may include supplying wash water to the spray arm by operating the wash pump, and diverting at least a portion of wash water that is supplied to the spray arm to the interior of the filter.

The method further comprises measuring the degree of contamination of wash water. The amount of wash water that is diverted to the interior of the filter in the washing is proportional to the measured degree of contamination of wash water.

When the measured degree of contamination of wash water is equal to or greater than a predetermined value, all of wash water that is introduced into the wash pump may be diverted to the interior of the filter.

The method may further include measuring the degree of contamination of wash water. The collecting may be performed until the measured degree of contamination of wash water becomes equal to or less than a predetermined value.

The wash pump may be operated at a first number of revolutions per minute (RPM) in the washing, and may be operated at a second RPM in the collecting, the second RPM being greater than the first RPM.

In a further aspect of the present invention, a method of controlling a dishwasher includes supplying wash water to the spray arm by operating the wash pump, diverting at least a portion of wash water that is supplied to the spray arm to the interior of the filter, and collecting foreign substances present in wash water in the interior of the filter by diverting all of wash water that is introduced into the wash pump to the interior of the filter.

The wash water supplied to the interior of the filter may pass through the filter due to the operation of the wash pump and may move to the exterior of the filter.

The wash pump may be rotated at a higher speed in the collecting than in the diverting.

The method may further include discharging foreign substances collected in the interior of the filter outside along with wash water.

The supplying, the diverting and the collecting may be performed in at least one of a preliminary washing process of soaking foreign substances by spraying water toward the dishes, a washing process of removing foreign substances by spraying water and detergent toward the dishes, a rinsing process of removing foreign substances and detergent remaining on the dishes by spraying water toward the dishes, or a heating-rinsing process of spraying heated water toward the dishes.

According to the present invention, a dishwasher is capable of diverting some or all of wash water that is supplied to a spray arm to the interior of a filter. The wash water supplied to the interior of the filter passes through the filter, at which time foreign substances are collected in the filter. Accordingly, it is possible to prevent foreign substances separated from an object to be washed from being again sprayed along with the wash water toward the object to be washed.

In addition, after the spraying of wash water is completed, all of the wash water stored in a sump is diverted to the interior of the filter, whereby foreign substances present in the sump are collected in the filter. Accordingly, it is possible to discharge most foreign substances along with the wash water in a draining process and to minimize the amount of foreign substances that remain in the sump after the draining process. In addition, it is possible to separate foreign substances from the outer circumferential surface of the filter through the aforementioned circulation process and consequently to prevent foreign substances from accumulating on the filter.

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. In the drawings, the same or similar elements are denoted by the same reference numerals even though they are depicted in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Additionally, terms such as "first", "second", "A", "B", "(a)", "(b)", etc. may be used herein to describe the components of the embodiments of the present invention. These terms are only used to distinguish one element from another element, and the essence, order, or sequence of corresponding elements are not limited by these terms. It should be noted that if it is described in the specification that one component is "connected", "coupled", or "joined" to another component, the former may be directly "connected", "coupled", or "joined" to the latter, or may be "connected", "coupled", or "joined" to the latter via another component.

<FIG> is a cross-sectional view of a dishwasher. <FIG> are, respectively, a perspective view and a side view of a sump and a lower spray arm depicted in <FIG>. <FIG> is a cross-sectional view taken along line I-I in the sump depicted in <FIG>. <FIG> is a cross-sectional view taken along line II-II in the sump depicted in <FIG>. <FIG> is an enlarged view of portion "A" in <FIG>.

Referring to <FIG>, a dishwasher <NUM> includes a housing forming the external appearance of the dishwasher, a tub <NUM> forming a washing compartment <NUM> inside the housing, a door <NUM> for selectively opening or closing the washing compartment <NUM>, a sump <NUM> provided below the tub <NUM> to store wash water therein, a containing unit <NUM> provided inside the tub <NUM> to contain an object to be washed therein, a spray arm <NUM> for spraying wash water toward the object to be washed that is contained in the containing unit <NUM>, and a filter assembly <NUM> for removing foreign substances from wash water.

The tub <NUM> forms the washing compartment <NUM>, in which an object to be washed is placed. The containing unit <NUM> and the spray arm <NUM> may be accommodated in the washing compartment <NUM>. The tub <NUM> may have one open surface, and the open surface of the tub <NUM> may be opened or closed by the door <NUM>.

The door <NUM> may be rotatably connected to the housing, and may selectively open or close the washing compartment <NUM>. For example, the door <NUM> may be coupled to the lower portion of the housing via a hinge. In this case, the door <NUM> may open or close the tub <NUM> by rotating about the hinge. When the door <NUM> is open, the containing unit <NUM> may be withdrawn out of the dishwasher <NUM>, and the containing unit <NUM> withdrawn outside may be supported by the door <NUM>.

The sump <NUM> may include a storage unit <NUM> for storing wash water, a sump cover <NUM> for separating the storage unit <NUM> from the tub <NUM>, a water supply unit <NUM> for supplying water to the storage unit <NUM>, a drain unit <NUM> for discharging water outside from the storage unit <NUM>, and a wash pump <NUM> and a flow passage unit <NUM> for supplying the water stored in the storage unit <NUM> to the spray arm <NUM>.

The filter assembly <NUM> for removing foreign substances from wash water may be accommodated in the storage unit <NUM>. At this time, the filter assembly <NUM> may be supported by a filter support portion <NUM>.

The storage unit <NUM> may be divided into an upper storage portion <NUM> and a lower storage portion <NUM> on the basis of the filter support portion <NUM>. As shown in <FIG>, the upper storage portion <NUM> may be in contact with the outer circumferential surface of the filter assembly <NUM>, and the lower storage portion <NUM> may communicate with the interior of the filter assembly <NUM>. When the wash water in the upper storage portion <NUM> moves to the lower storage portion <NUM>, as indicated by the arrow F1, the wash water passes through a mesh member <NUM> (refer to <FIG>) of the filter assembly <NUM>. In the same way, when the wash water in the lower storage portion <NUM> moves to the upper storage portion <NUM>, as indicated by the arrow F2, the wash water passes through the mesh member <NUM> of the filter assembly <NUM>.

The upper storage portion <NUM> may be connected with the water supply unit <NUM> and the wash pump <NUM>, and the lower storage portion <NUM> may be connected with the drain unit <NUM> and a circulation passage <NUM>. Through this component connection structure, foreign substances present in wash water may collect on the mesh member <NUM> of a filter <NUM>. A detailed description thereof will be made later.

Alternatively, the filter support portion <NUM> may not be provided inside the sump <NUM>, and the mesh member <NUM> may extend to the bottom surface of the storage unit <NUM>. In this case, the circulation passage <NUM> and the drain unit <NUM> may penetrate the bottom surface of the storage unit <NUM> and may communicate with the internal space in the mesh member <NUM>.

The sump cover <NUM> may be provided on the sump <NUM> and may separate the tub <NUM> and the sump <NUM> from each other. The sump cover <NUM> may have therein a through-hole <NUM> for mounting the filter assembly <NUM> thereto and a plurality of collection holes <NUM> (refer to <FIG>) for collecting the wash water, which was sprayed from the spray arm <NUM> to the washing compartment <NUM>. The wash water sprayed from the spray arm <NUM> may drop to the lower portion of the washing compartment <NUM> and may collect in the storage unit <NUM> of the sump <NUM> via the filter assembly <NUM> and the collection holes <NUM>.

The water supply unit <NUM> may be connected to an external water source and may supply water to the storage unit <NUM>. At this time, in order to prevent the wash water or foreign substances in the storage unit <NUM> from moving back to the water supply unit <NUM>, it is desirable for the water supply unit <NUM> to be connected to the upper portion of the storage unit <NUM>. As shown in <FIG>, in this embodiment, the water supply unit <NUM> is connected to the upper portion of the storage unit <NUM> and supplies water to the upper storage portion <NUM>.

The drain unit <NUM> may include a drain pump <NUM> and a drain passage <NUM> and may discharge the wash water in the storage unit <NUM> outside the dishwasher <NUM>. When the drain pump <NUM> operates, the wash water in the storage unit <NUM> is discharged outside through the drain passage <NUM>.

After a washing process is performed, foreign substances such as food waste or the like may be included in the water collected in the storage unit <NUM>. Therefore, if not all of the water in the storage unit <NUM> is discharged, it may lead to the propagation of bacteria, poor sanitation, and bad smells. In order to prevent this problem, it is desirable to connect the drain unit <NUM> to the lower portion of the storage unit <NUM>.

Further, foreign substances such as food waste or the like may be discharged along with wash water during a draining process. At this time, the foreign substances may block the drain unit <NUM>. As shown in <FIG> and <FIG>, in this embodiment, the drain passage <NUM> is connected to the lower storage portion <NUM>. Because the lower storage portion <NUM> communicates with the interior of the filter assembly <NUM>, relatively large foreign substances may be filtered out by the filter assembly <NUM>. Accordingly, it is possible to prevent the drain unit <NUM> from being blocked by foreign substances present in wash water.

The wash pump <NUM> may supply the wash water stored in the storage unit <NUM> to the spray arm <NUM>. In addition, the wash pump <NUM> may supply the wash water stored in the storage unit <NUM> to the circulation passage <NUM> so that the wash water flows back to the storage unit <NUM>.

One end of the wash pump <NUM> may be connected to the upper storage portion <NUM>, and the other end of the wash pump <NUM> may be connected to a flow-switching unit <NUM>. A connection pipe <NUM> may be provided to connect the storage unit <NUM>, the wash pump <NUM> and the flow-switching unit <NUM> to each other as needed.

The wash pump <NUM> may include a housing <NUM>, in which an impeller <NUM> is provided, an inlet port <NUM> connected with the storage unit <NUM>, an outlet port <NUM> connected with the flow-switching unit <NUM>, and a motor <NUM> for rotating the impeller <NUM>.

When power is supplied to the motor <NUM>, the impeller <NUM> may be rotated, and the wash water in the storage unit <NUM> may be supplied to the flow passage unit <NUM> via the flow-switching unit <NUM>.

The flow passage unit <NUM> may include a first supply passage <NUM> connected to a lower spray arm <NUM>, a second supply passage <NUM> connected to an upper spray arm <NUM> and a top nozzle <NUM>, and the circulation passage <NUM> connected to the storage unit <NUM>. When the first supply passage <NUM> is opened, wash water may be supplied to the lower spray arm <NUM>. When the second supply passage <NUM> is opened, wash water may be supplied to the upper spray arm <NUM> and the top nozzle <NUM>. In addition, when the circulation passage <NUM> is opened, wash water may be supplied back to the storage unit <NUM>.

As shown in <FIG> and <FIG>, the circulation passage <NUM> may be connected to the lower storage portion <NUM>. That is, the wash water that circulates through the circulation passage <NUM> may be supplied to the lower storage portion <NUM>, and may then move in the direction indicated by the arrow F2. In this process, foreign substances present in the wash water may collect on the inner surface of the mesh member <NUM>.

The flow-switching unit <NUM> may selectively or simultaneously open the first and second supply passages <NUM> and <NUM> and the circulation passage <NUM>. The flow-switching unit <NUM> may be embodied by a valve, a rotary plate, or the like. The flow-switching unit <NUM> may have various other configurations, as long as it can distribute wash water to various passages. For example, the flow-switching unit <NUM> may be an electronically controlled switch valve. In this case, the supply passages <NUM> and <NUM> and the circulation passage <NUM> may be selectively opened or closed by controlling the switch valve.

Hereinafter, the case in which the flow-switching unit <NUM> has a rotary-plate configuration will be described in detail.

As shown in <FIG> and <FIG>, the flow-switching unit <NUM> may include a flow-switching plate <NUM>, having therein a plurality of openings <NUM> and <NUM>, and a flow-switching motor <NUM> for rotating the flow-switching plate <NUM> via a rotary shaft <NUM>. The flow-switching plate <NUM> may be rotated by the flow-switching motor <NUM>, and the first and second supply passages <NUM> and <NUM> and the circulation passage <NUM> may be selectively opened or closed depending on the location of the flow-switching plate <NUM>.

For example, when the flow-switching plate <NUM> moves to the location shown in <FIG>, the first supply passage <NUM>, the second supply passage <NUM> and the circulation passage <NUM> may be opened simultaneously. In this case, the wash water in the storage unit <NUM> may be supplied to the spray arms <NUM>, <NUM> and <NUM>, and a portion of the wash water may be diverted to the lower storage portion <NUM> through the circulation passage <NUM>.

The wash water supplied to the lower storage portion <NUM> through the circulation passage <NUM> may move in the direction indicated by the arrow F2. In this process, foreign substances present in the wash water may collect on the inner circumferential surface of the mesh member <NUM>. The wash water, from which foreign substances have been removed, may move to the upper storage portion <NUM>, and may then be supplied to the spray arm <NUM> via the wash pump <NUM>. Therefore, it is possible to prevent an object to be washed from being recontaminated with foreign substances present in wash water.

The foreign substances, which have been removed from wash water, may accumulate on the outer circumferential surface of the mesh member <NUM>. The foreign substances accumulated on the outer circumferential surface of the mesh member <NUM> may hinder the flow of wash water, and may deteriorate the filtering performance of the mesh member <NUM>. However, the wash water circulating through the circulation passage <NUM> moves from the interior of the mesh member <NUM> to the exterior of the mesh member <NUM> in the direction indicated by the arrow F2, thereby separating the foreign substances from the outer circumferential surface of the mesh member <NUM>. That is, it is also possible to obtain an effect of removing foreign substances accumulated on the outer circumferential surface of the mesh member <NUM> using the circulation of wash water.

When the flow-switching plate <NUM> moves to the location shown in <FIG>, only the circulation passage <NUM> may be opened. That is, the first supply passage <NUM> and the second supply passage <NUM> may be closed, and wash water may not be supplied to the spray arm <NUM>. In this case, all of the wash water that is supplied from the wash pump <NUM> to the flow-switching unit <NUM> is supplied to the lower storage portion <NUM> through the circulation passage <NUM>. The wash water supplied to the lower storage portion <NUM> through the circulation passage <NUM> may move in the direction indicated by the arrow F2. In this process, foreign substances present in the wash water may collect on the inner circumferential surface of the mesh member <NUM>.

Unlike the state described above with reference to <FIG>, in the state in which the flow-switching plate <NUM> is located as shown in <FIG>, all of the wash water that is supplied from the upper storage portion <NUM> to the flow-switching unit <NUM> may return into the upper storage portion <NUM> via the circulation passage <NUM> and the mesh member <NUM>. Therefore, the amount of foreign substances present in the wash water, which is stored in the upper storage portion <NUM>, may be rapidly reduced. In addition, the foreign substances accumulated on the outer circumferential surface of the mesh member <NUM> may also be removed more rapidly.

It is illustrated in <FIG> and <FIG> that the first opening <NUM> has a size capable of opening both the first supply passage <NUM> and the circulation passage <NUM> at the same time and that the second opening <NUM> is smaller than the first opening <NUM>. However, this is merely illustrative, and the present invention is not limited thereto. For example, the flow-switching plate <NUM> may have therein three openings, each of which corresponds to a respective one of the supply passages <NUM> and <NUM> and the circulation passage <NUM>.

Although it is illustrated in <FIG> and <FIG> that the circulation passage <NUM> is formed separately from the supply passages <NUM> and <NUM>, the present invention is not limited thereto. For example, the circulation passage <NUM> may be branched from the first supply passage <NUM> or from the second supply passage <NUM>. In this case, when the first supply passage <NUM> is opened, a portion of the wash water that is supplied to the lower spray arm <NUM> is always diverted to the sump <NUM> through the circulation passage <NUM>. When the second supply passage <NUM> is opened, a portion of the wash water that is supplied to the upper spray arm <NUM> and the top nozzle <NUM> is always diverted to the sump <NUM> through the circulation passage <NUM>.

At least one containing unit <NUM> for containing an object to be washed may be provided inside the washing compartment <NUM>. Although it is illustrated in <FIG> that the dishwasher <NUM> is provided with two containing units, the present invention is not limited thereto. For example, the dishwasher <NUM> may include a single containing unit, or may include three or more containing units. In this case, the number of spray arms may vary depending on the number of containing units. Hereinafter, an explanation of the dishwasher <NUM> having two containing units will be made for convenience of description.

The containing unit <NUM> may include a lower rack <NUM> and an upper rack <NUM>, which are configured to contain an object to be washed. The lower rack <NUM> may be disposed above the sump <NUM>, and the upper rack <NUM> may be disposed above the lower rack <NUM>. The lower rack <NUM> and the upper rack <NUM> may be withdrawn outside through the open surface of the tub <NUM>. To this end, the tub <NUM> may be provided on the inner circumferential surface thereof with rails (not shown), and the racks <NUM> and <NUM> may be provided at the lower portions thereof with wheels. A user can place an object to be washed in the containing unit <NUM>, or can take an object to be washed, which has been completely washed, out of the containing unit <NUM> by withdrawing the containing unit <NUM> outside.

The spray arm <NUM> may be provided inside the tub <NUM> in order to spray wash water toward an object to be washed placed in the containing unit <NUM>.

The spray arm <NUM> may include the lower spray arm <NUM>, the upper spray arm <NUM>, and the top nozzle <NUM>. The lower spray arm <NUM> may be rotatably mounted on the sump cover <NUM> in order to spray wash water toward an object to be washed contained in the lower rack <NUM>. The upper spray arm <NUM> may be disposed above the lower spray arm <NUM> in order to spray wash water toward an object to be washed contained in the upper rack <NUM>. The top nozzle <NUM> may be disposed at the top of the washing compartment <NUM> in order to spray wash water toward the lower rack <NUM> and the upper rack <NUM>. As described above, the first supply passage <NUM> may supply wash water to the lower spray arm <NUM>, and the second supply passage <NUM> may supply wash water to the upper spray arm <NUM> and the top nozzle <NUM>.

The filter assembly <NUM> may be removably mounted to the sump <NUM> through the through-hole <NUM> formed in the sump cover <NUM>. If a large amount of foreign substances accumulates in the filter assembly <NUM> due to repetition of the washing process, a user can separate the filter assembly <NUM> from the sump <NUM> and can remove foreign substances from the filter assembly <NUM>. Hereinafter, the configuration of the filter assembly <NUM> will be described in detail with reference to <FIG> and <FIG>.

<FIG> and <FIG> are views illustrating the filter assembly depicted in <FIG>.

Referring to <FIG> and <FIG>, the filter assembly <NUM> may include the filter <NUM>, which is inserted into the sump <NUM> in order to filter out foreign substances, and a handle member <NUM>, which is coupled to the top of the filter <NUM>. The handle member <NUM> is provided to facilitate mounting and demounting of the filter <NUM>. The handle member <NUM> may be omitted as needed.

Although it is illustrated in <FIG> that the handle member <NUM> is separably coupled to the filter <NUM>, the present invention is not limited thereto. For example, the handle member <NUM> and the filter <NUM> may be formed integrally with each other.

The filter <NUM> may include a seat portion <NUM>, which is seated on a portion of the sump cover <NUM> around the through-hole <NUM>, the mesh member <NUM>, which extends downwards from the seat portion <NUM> in order to remove foreign substances from the wash water stored in the storage unit <NUM>, a support rib <NUM>, which extends downwards from the seat portion <NUM> in order to support the mesh member <NUM>, a support rim <NUM>, which is provided at the lower end of the support rib <NUM> and is seated on the filter support portion <NUM>, and a core member <NUM>, which is provided on the seat portion <NUM> in order to remove foreign substances from the wash water that flows to the mesh member <NUM> from the region above the sump cover <NUM>.

The seat portion <NUM> may have therein an insertion hole <NUM> for fixing the handle member <NUM>. An extension rib <NUM> of the handle member <NUM> may be inserted into the insertion hole <NUM>. The shape and number of insertion holes <NUM> may be set so as to correspond to the shape and number of extension ribs <NUM>.

The support rib <NUM> may be inserted into the sump <NUM>, and may support the mesh member <NUM> so that the shape of the mesh member <NUM> can be maintained constant. In order to support the mesh member <NUM> more securely, there may be further provided a reinforcement ring <NUM>, which is formed so as to intersect with the support rib <NUM>. At this time, the number of support ribs <NUM> and the number of reinforcement rings <NUM> may be set properly depending on the size and material of the mesh member <NUM>.

The support rim <NUM> may be in contact with the filter support portion <NUM> of the sump <NUM>, and may support the filter <NUM>. That is, the filter <NUM> may be securely fixed inside the sump <NUM> in a manner such that the seat portion <NUM> and the support rim <NUM> are in contact with the sump cover <NUM> and the filter support portion <NUM>, respectively. Accordingly, even when wash water moves inside the sump <NUM>, the filter <NUM> may be prevented from being moved.

In addition, although not illustrated, in order to fix the filter <NUM> to the sump <NUM> more securely, the support rim <NUM> may be provided at the bottom or the side portion thereof with a fastening member. For example, the filter support portion <NUM> may be provided with a fastening hole (not shown) having therein threads, and the fastening member, which is inserted into the fastening hole, may be provided at the bottom of the support rim <NUM>. The fastening member may also have threads formed in the outer surface thereof. The fastening member may be inserted into the fastening hole and may be rotated so as to be securely engaged with the fastening hole. Accordingly, it is possible to fix the filter <NUM> to the sump <NUM> more securely.

The mesh member <NUM> may be mounted between the seat portion <NUM> and the support rim <NUM> and may remove foreign substances from wash water. Since the mesh member <NUM> is mounted in a cylindrical shape along the support rib <NUM> and the reinforcement ring <NUM>, the top and bottom of the mesh member <NUM> may be open. The top of the mesh member <NUM> may be covered with the core member <NUM>, and the bottom of the mesh member <NUM> may communicate with the lower storage portion <NUM>. This is illustrated in <FIG>.

When wash water moves into the filter <NUM> from the exterior of the filter <NUM>, foreign substances present in the wash water may collect on the outer circumferential surface of the mesh member <NUM>. Conversely, when wash water moves out of the filter <NUM> from the interior of the filter <NUM>, foreign substances present in the wash water may collect on the inner circumferential surface of the mesh member <NUM>.

Specifically, as shown in <FIG>, the wash water that is supplied into the filter <NUM> through the core member <NUM> and the circulation passage <NUM> may pass through the mesh member <NUM> in the direction indicated by the arrow F2. Accordingly, foreign substances present in the wash water may be caught on the inner circumferential surface of the mesh member <NUM>, and the wash water, from which foreign substances have been removed, may be supplied to the spray arm <NUM> through the wash pump <NUM>.

The wash water sprayed from the spray arm <NUM> may be introduced into the storage unit <NUM> through the core member <NUM>, and may also be introduced into the storage unit <NUM> through the collection holes <NUM> formed in the sump cover <NUM>. In this case, the wash water may be introduced into the upper storage portion <NUM>. The wash water introduced into the upper storage portion <NUM> may pass through the mesh member <NUM> in the direction indicated by the arrow F1, and foreign substances present in the wash water may collect on the outer circumferential surface of the mesh member <NUM>.

The core member <NUM> may cover the top of the mesh member <NUM> and may remove foreign substances from wash water.

As shown in <FIG>, the core member <NUM> may include a core <NUM> provided above the seat portion <NUM> and a plurality of ribs interconnecting the core <NUM> and the seat portion <NUM>. The ribs may include radial ribs <NUM> and reinforcement ribs <NUM>, which intersect with each other. The core <NUM>, the radial ribs <NUM> and the reinforcement ribs <NUM> may define first and second holes <NUM> and <NUM> therebetween, which communicate with the interior of the filter <NUM>. Wash water may be introduced into the filter <NUM> through the first and second holes <NUM> and <NUM>. At this time, stick-type foreign substances such as toothpicks or the like may be filtered out.

The core <NUM> may have a guide hole <NUM> formed in the top thereof, into which a guide rib <NUM> of the handle member <NUM> is fitted.

The handle member <NUM> may include a ring-shaped body <NUM>, a plurality of extension ribs <NUM>, which extend downwards from the body <NUM> and are coupled to the filter <NUM>, and a handle <NUM>, which is formed across the body <NUM>. The handle member <NUM> may be separably coupled to the filter <NUM>. A user can insert the filter <NUM> into the sump <NUM> or take the filter <NUM> out of the sump <NUM> while grabbing the handle <NUM>.

Each of the extension ribs <NUM> may be inserted into the insertion hole <NUM> formed in the seat portion <NUM> of the filter <NUM>. In order to prevent the extension rib <NUM> from being separated from the seat portion <NUM>, the extension rib <NUM> may be provided at the lower end thereof with a hook <NUM>. The hook <NUM> may include an inclined surface <NUM>, which extends at an incline from the lower end of the extension rib <NUM> toward the center of the body <NUM>, and a latching surface <NUM>. When the hook <NUM> is inserted into the insertion hole <NUM>, the latching surface <NUM> comes into contact with the bottom surface of the seat portion <NUM>. Accordingly, the extension rib <NUM> may be fixed on the seat portion <NUM>.

In order to adjust the depth to which the extension rib <NUM> is inserted into the insertion hole <NUM>, the body <NUM> may be provided with gap-maintaining protrusions <NUM>. The gap-maintaining protrusions <NUM> protrude from the bottom surface of the body <NUM>. When the handle member <NUM> is coupled to the seat portion <NUM>, the gap-maintaining protrusions <NUM> may come into contact with the top surface of the seat portion <NUM>, thereby preventing the extension rib <NUM> from being inserted into the insertion hole <NUM> beyond a predetermined depth.

In addition, the handle <NUM> may be provided at the bottom surface thereof with the guide rib <NUM>, which guides the coupling of the handle member <NUM> to the filter <NUM>. The guide rib <NUM> may be inserted into the guide hole <NUM> formed in the core member <NUM>, whereby the handle member <NUM> can be coupled to the filter <NUM> in a correct direction.

As described above, the dishwasher <NUM> according to the embodiment of the present invention is capable of diverting some or all of the wash water that is supplied from the wash pump <NUM> to the sump <NUM>. In particular, the diverted wash water is supplied to the interior of the filter <NUM>, whereby foreign substances present in the wash water are filtered out inside the filter <NUM>. In addition, when the diverted wash water passes through the filter <NUM>, it can separate foreign substances from the outer surface of the filter <NUM>. Accordingly, it is possible to prevent an object to be washed from being recontaminated with foreign substances present in wash water and to prevent the filter <NUM> from being blocked by foreign substances present in wash water.

Hereinafter, a method of washing dishes using the above-described dishwasher <NUM> will be described in detail.

<FIG> is a flowchart for explaining a method of controlling the dishwasher depicted in <FIG>.

First, when power is applied to the dishwasher <NUM>, at least one of a course or an option for washing dishes is loaded (S100).

Here, the course may include at least one selected from among a preliminary washing process (S200), a washing process (S300), a rinsing process (S400), a heating-rinsing process (S500), a drying process (S600), and combinations thereof. For example, a first course may be set to include the washing process and the rinsing process, and a second course may be set to include the preliminary washing process, the washing process, the rinsing process, the heating-rinsing process, and the drying process.

The preliminary washing process may be a process of spraying water toward an object to be washed that is accommodated in the washing compartment <NUM> and of soaking the same so as to easily remove foreign substances from the object to be washed.

The washing process may be a process of removing foreign substances from the object to be washed by spraying water and detergent toward the same.

The rinsing process may be a process of removing foreign substances and detergent remaining on the object to be washed by spraying water toward the same. At this time, a rinsing agent may be sprayed along with water in order to disinfect the object to be washed. In addition, the rinsing agent may serve to weaken the surface tension of the water on the surface of the object to be washed, thereby making the water run down easily and consequently shortening the time taken to dry the object to be washed.

The heating-rinsing process may be a process of heating the object to be washed by spraying water that was heated to a predetermined temperature toward the same so as to shorten the time taken to dry the object to be washed and to disinfect the same.

The drying process may be a process of removing moisture from the surface of the object to be washed. In this case, the object to be washed may be dried passively. Alternatively, a drying fan (not shown) may be operated in order to discharge the air in the tub <NUM> to the outside, thereby shortening the drying time.

The option may be the operating conditions under which each process of the selected course is operated. For example, the operating conditions may be information about the temperature of water that is supplied to the object to be washed in the heating-rinsing process, an operating time of the drying fan in the drying process, the number of repetitions of each process, or the like.

When power is applied to the dishwasher <NUM>, information about the most-recently performed course and related options may be loaded, or information about the course that has been performed most frequently during a predetermined period and related options may be loaded. Alternatively, a user may directly input information about the course and the option. The loading type may be set variously depending on the user's selection.

Subsequently, according to the set course and option, at least one of the preliminary washing process (S200), the washing process (S300), the rinsing process (S400), the heating-rinsing process (S500), or the drying process (S600) is performed.

In all of the preliminary washing process (S200), the washing process (S300), the rinsing process (S400), and the heating-rinsing process (S500), wash water may be sprayed from the spray arm <NUM>. The sprayed wash water may collect in the sump <NUM>, and foreign substances, which were removed from the object to be washed, may be included in the collected wash water.

The present invention is capable of removing foreign substances present in wash water by diverting a portion of sprayed wash water to the interior of the filter <NUM> and of removing foreign substances accumulated on the outer circumferential surface of the filter <NUM> by diverting all of wash water stored in the sump <NUM> to the interior of the filter <NUM> after the process is completed. Therefore, the present invention can be applied in the same or a similar way to every process in which the spraying of wash water is performed.

For convenience of description, the washing process (S300), to which the present invention is applied, will now be described in detail with reference to <FIG>. However, the present invention should not be construed as being applied only to the washing process (S300). The present invention can be applied in the same or a similar way to every process in which wash water is sprayed toward an object to be washed.

<FIG> is a flowchart showing the washing process of <FIG>. <FIG> is a flowchart showing a dish-washing step of <FIG>. <FIG> is a flowchart showing a filter-washing step of <FIG>.

First, the water supply unit <NUM> supplies water to the interior of the sump <NUM> (S310). At this time, detergent or the like may be supplied along with the water in order to improve washing performance.

Dishes are washed using the water (hereinafter referred to as "wash water") stored in the sump <NUM> (S320).

For example, the wash water in the storage unit <NUM> is supplied to the flow-switching unit <NUM> by operating the wash pump <NUM> (S321). The flow-switching unit <NUM> may selectively open or close the first supply passage <NUM> and the second supply passage <NUM> according to the selected option and may supply the wash water to the spray arm <NUM> through the opened passage (S322). If the first supply passage <NUM> is opened, the wash water may be supplied to the lower spray arm <NUM>. If the second supply passage <NUM> is opened, the wash water may be supplied to the upper spray arm <NUM> and the top nozzle <NUM>.

The wash water supplied to the spray arm <NUM> is sprayed toward dishes contained in the containing unit <NUM>. The sprayed wash water may collide with the dishes, may fall to the sump cover <NUM>, and may collect in the upper storage portion <NUM> through the through-hole <NUM> and the collection holes <NUM>. The wash water introduced into the through-hole <NUM> may collect in the interior of the filter <NUM> through the core member <NUM>, and the wash water introduced into the collection holes <NUM> may collect in the exterior of the filter <NUM>. Here, the interior of the filter <NUM> is a region that is contiguous with the inner circumferential surface of the mesh member <NUM>, and the exterior of the filter <NUM> is a region that is contiguous with the outer circumferential surface of the mesh member <NUM>.

The collected wash water may be again sprayed toward the dishes via the wash pump <NUM> and the spray arm <NUM> in that order. Through this circulation mechanism, wash water may be consistently sprayed toward the dishes.

As shown in <FIG>, the wash pump <NUM> may be connected to the upper storage portion <NUM>. Therefore, the wash water stored in the interior of the filter <NUM> may be moved to the exterior of the filter <NUM> in the direction indicated by the arrow F2, and may then be supplied to the wash pump <NUM>. At this time, since the wash water passes through the mesh member <NUM> of the filter <NUM>, foreign substances present in the wash water may collect on the inner circumferential surface of the mesh member <NUM>.

On the other hand, the wash water stored in the exterior of the filter <NUM> may be directly introduced into the wash pump <NUM> without passing through the mesh member <NUM>. Thus, the wash water, in which foreign substances are included, may be sprayed toward the dishes through the spray arm <NUM>.

In order to prevent this, in the present invention, a portion of the wash water that is supplied to the spray arm <NUM> is diverted to the interior of the filter <NUM>, thereby removing foreign substances from the wash water (S323).

Specifically, a portion of the wash water that is supplied from the wash pump <NUM> to the spray arm <NUM> is supplied to the storage unit <NUM> through the circulation passage <NUM>. At this time, the flow-switching unit <NUM> may be controlled so as to open the circulation passage <NUM>. For example, the flow-switching plate <NUM> may be rotated to the location shown in <FIG> by operating the flow-switching motor <NUM> so as to open the circulation passage <NUM>.

As shown in <FIG>, the circulation passage <NUM> is connected to the lower storage portion <NUM>, which communicates with the interior of the filter <NUM>. Therefore, the wash water supplied through the circulation passage <NUM> may pass through the mesh member <NUM> of the filter <NUM> in the direction indicated by the arrow F2, and foreign substances present in the wash water may collect on the inner circumferential surface of the filter <NUM>. If this circulation is repeated while the wash water is sprayed, foreign substances present in the wash water may collect on the inner circumferential surface of the filter <NUM>. Accordingly, the wash water, from which foreign substances have been removed, may be supplied to the spray arm <NUM>, thereby preventing recontamination of the dishes.

In this case, the amount of wash water that is diverted to the interior of the filter <NUM> may be adjusted variously as needed. A sensor (not shown) for measuring the contamination of wash water is mounted in the sump <NUM>, and the amount of wash water that is diverted is controlled depending on the degree of contamination of the wash water. Particularly, when the contamination of wash water is severe, the supply of wash water to the spray arm <NUM> may be stopped for a predetermined time period, and all of the wash water that is introduced into the wash pump <NUM> may be diverted through the circulation passage <NUM>.

After the spraying of wash water through the spray arm <NUM> is performed for a predetermined time period (S324), the operation of the wash pump <NUM> is stopped (S325) and the dish-washing step (S320) is terminated.

When the dish-washing step is terminated, the wash water stored in the storage unit <NUM> is discharged outside. At this time, foreign substances present in the wash water are also discharged outside along with the wash water. However, as shown in <FIG>, because the lower storage portion <NUM>, to which the drain passage <NUM> is connected, communicates with the interior of the filter <NUM>, foreign substances present in the exterior of the filter <NUM> may not be discharged along with the wash water. That is, when the drain pump <NUM> is operated, the wash water stored in the exterior of the filter <NUM> moves to the drain passage <NUM> in the direction indicated by the arrow F1, and at this time, foreign substances present in the wash water may collect on the outer circumferential surface of the mesh member <NUM>. Thus, the foreign substances collected on the outer circumferential surface of the mesh member <NUM> may not be discharged outside and may remain inside the sump <NUM>. This may be a cause of recontamination of the dishes in the rinsing process (S300) that is subsequently performed. In addition, the filter <NUM> may be blocked, or may not perform its role normally due to the foreign substances accumulated on the mesh member <NUM>.

In order to solve this problem, in the present invention, before the wash water is discharged, foreign substances present in the wash water are collected in the interior of the filter <NUM> (S330), and the collected foreign substances are discharged outside along with the wash water (S340).

Specifically, the wash pump <NUM> is operated (S331), and all of the wash water stored in the storage unit <NUM> is diverted to the interior of the filter <NUM> (S332). For example, the flow-switching plate <NUM> is moved to the location shown in <FIG> in order to open only the circulation passage <NUM>. Since the first and second supply passages <NUM> and <NUM> are closed, the wash water is not supplied to the spray arm <NUM>, and all of the wash water introduced into the wash pump <NUM> moves to the lower storage portion <NUM> through the circulation passage <NUM>. The wash water introduced through the circulation passage <NUM> passes through the mesh member <NUM> of the filter <NUM> in the direction indicated by the arrow F2, and foreign substances present in the wash water are collected on the inner circumferential surface of the filter <NUM>. Subsequently, the wash pump <NUM> is consistently operated for a predetermined time period, and thus most foreign substances present in the wash water are collected on the inner circumferential surface of the filter <NUM>.

While the foreign-substance-collecting step (S330) is performed, the wash water moves in the direction indicated by the arrow F2. At this time, the wash water collides with the mesh member <NUM> of the filter <NUM>. The force generated by this collision separates foreign substances from the outer circumferential surface of the mesh member <NUM>. The separated foreign substances collect inside the mesh member <NUM> after passing through the wash pump <NUM> and the circulation passage <NUM>, and are then discharged outside in the draining step (S340). As such, the foreign-substance-collecting step (S330) may also have an effect of removing foreign substances accumulated on the outer circumferential surface of the mesh member <NUM>.

In one embodiment, the wash pump <NUM> may be operated at a higher speed in the foreign-substance-collecting step (S330) than in the dish-washing step (S320).

For example, assuming that the impeller <NUM> of the wash pump <NUM> is rotated at a first number of revolutions per minute (RPM) in the dish-washing step (S320) and is rotated at a second RPM in the foreign-substance-collecting step (S330), the second RPM may be greater than the first RPM. The reason for this is to increase the pressure at which the wash pump <NUM> sucks the wash water and consequently to remove foreign substances adhering to the outer circumferential surface of the mesh member <NUM> more easily. In this case, it is possible to enhance an effect of removing foreign substances accumulated on the outer circumferential surface of the mesh member <NUM> and to shorten the operating time of the foreign-substance-collecting step (S330).

After the collection of foreign substances using the circulation of the wash water is performed for a predetermined time period (S333), the operation of the wash pump <NUM> is stopped (S334) and the foreign-substance-collecting step (S330) is terminated. Subsequently, the drain pump <NUM> is operated in order to discharge the wash water and foreign substances outside the dishwasher <NUM> (S340).

Unlike the above configuration, in the case in which a sensor (not shown) for measuring the contamination of wash water is provided at the dishwasher <NUM>, when the degree of contamination of the wash water is equal to or drops below a predetermined value, the operation of the wash pump <NUM> may be stopped (S334), and the foreign-substance-collecting step (S330) may be terminated.

As described above, the method of controlling the dishwasher according to the present invention is capable of removing foreign substances from wash water by diverting some or all of the wash water that is supplied to the spray arm <NUM> to the interior of the filter <NUM>. Accordingly, it is possible to prevent foreign substances separated from the dishes from being again sprayed along with the wash water toward the dishes.

In addition, after the spraying of wash water through the spray arm <NUM> is completed, all of the wash water stored in the sump <NUM> may be diverted to the interior of the filter <NUM>, whereby foreign substances present in the wash water may collect in the filter <NUM>. Accordingly, it is possible to discharge most foreign substances along with the wash water in the draining process and to minimize the amount of foreign substances that remain in the sump <NUM> after the draining process. In addition, it is possible to separate foreign substances from the outer circumferential surface of the filter <NUM> through the aforementioned circulation process and consequently to prevent foreign substances from accumulating on the filter <NUM>.

Various embodiments have been described in the best mode for carrying out the invention.

Claim 1:
A method of controlling a dishwasher (<NUM>) comprising a tub (<NUM>) for accommodating dishes,
a spray arm (<NUM>) for spraying wash water toward the dishes,
a sump (<NUM>) for storing wash water,
a filter (<NUM>) provided inside the sump (<NUM>) in order to remove foreign substances from wash water, and
a wash pump (<NUM>) for supplying wash water stored in the sump (<NUM>) to the spray arm (<NUM>), the method comprising:
washing the dishes, the washing including supplying wash water to the spray arm (<NUM>) and diverting at least a portion of wash water that is supplied to the spray arm to the interior of the filter;
collecting foreign substances present in wash water in an interior of the filter (<NUM>) by diverting all of wash water that is introduced into the wash pump (<NUM>) to the interior of the filter (<NUM>), the collecting being performed after the washing is completed; discharging foreign substances collected in the interior of the filter (<NUM>) outside along with wash waters
characterized by measuring a degree of contamination of wash water,
wherein an amount of wash water that is diverted to the interior of the filter (<NUM>) in the washing is proportional to the measured degree of contamination of wash water.