Patent Description:
Water purifiers are apparatuses for filtering raw water supplied from the outside and providing potable water to users. To this end, a water purifier includes elements such as at least one filter configured to filter raw water, a plurality of pipes along which the raw water or clean water flows, and a valve configured to control the flow of the raw water or the clean water.

When the water purifier is used for a long period of time, foreign matter may be stuck in the pipes or the valve or microorganisms may be formed and attached to an inner wall, and thus a smooth flow of the raw water or the clean water may be impeded, and contaminated water may be provided to a user.

Here, in a case where the time during which the water purifier is not in use becomes long according to a pattern of using the water purifier, the time during which the raw water or the clean water inside the water purifier stagnates may become long, and contamination may be accelerated.

Therefore, the conventional water purifier has adopted a method of forming sterilizing water and letting the sterilizing water flow through the pipes to clean the elements, and a user manual of the conventional water purifier guides a user to discharge water from inside the water purifier and discard the water before using the water purifier.

Document <CIT> discloses a water purifier which processes natural water, such as a tap water, by a filtration cartridge, manufactures clean water, and stores clean water in a tank. An antimicrobial unit is disposed between the switching valve and the tank to elute an antimicrobial metal ion from the electrode for suppressing reproduction of standard bacteria in the stagnant water of the tank.

Document <CIT> discloses a self-cleaning water purifier for directly replacing a water filter for purifying raw water or for cleaning the inside of a water pipe downstream of the water filter.

It is an aspect of the present invention to provide a water purifier which automatically cleans the inside on the basis of external environment information, such as an installation environment and raw water contamination, or the remaining life of a filter.

A water purifier includes a communication device, a raw water flow path into which raw water is introduced from the outside, a clean water flow path connected to the raw water flow path and having a water discharge nozzle disposed at an end, a filter disposed in the clean water flow path to filter the raw water, a drain flow path branched off from the clean water flow path between the filter and the water discharge nozzle and connected to a drain port to drain a liquid in the clean water flow path to the outside, a drain valve configured to open or close the drain flow path, and a controller configured to determine the remaining life of the filter on the basis of a point in time at which the filter has been replaced and control the drain valve to perform a cleaning operation on the basis of external environment information received through the communication device or on the basis of the remaining life of the filter.

The water purifier may further include a flow rate sensor configured to detect a flow rate in the clean water flow path, and, in response to the flow rate in the clean water flow path being less than or equal to a predetermined value during a drainage reference time, the controller may control the drain valve to discharge stagnant water and perform the cleaning operation.

The controller may adjust the drainage reference time to decrease with a decrease in the remaining life of the filter.

The controller may adjust the drainage reference time to decrease in stages according to the remaining life of the filter.

The water purifier may further include a filter water passage flow path which includes one end connected to the filter and the other end connected to the drain port and through which raw water including impurities from the filter is drained and a filter water passage valve which is configured to open or close the filter water passage flow path.

In response to the flow rate in the clean water flow path being less than or equal to a predetermined value during the drainage reference time, the controller may control the drain valve and the filter water passage valve to drain stagnant water in the clean water flow path to the filter water passage flow path during a predetermined amount of time and may control the drain valve and the filter water passage valve to drain the stagnant water in the clean water flow path to the drain flow path after the predetermined amount of time.

In a case in which the controller receives information on an occurrence of contamination in the raw water as the external environment information through the communication device, the controller may control the filter water passage valve to open the filter water passage flow path.

The controller may control the filter water passage valve to repeat opening and closing in a predetermined cycle, and, in response to the remaining life of the filter being less than a predetermined value, the controller may stop controlling the filter water passage valve in the predetermined cycle.

In a case in which the controller receives information on an installation environment indicating an uncontaminated area as the external environment information through the communication device, the controller may control the filter water passage valve to close the filter water passage flow path.

The water purifier may further include a sterilizing water flow path which includes one end connected to the raw water flow path for the raw water to bypass the filter and the other end connected to the clean water flow path between the filter and the water discharge nozzle and in which a sterilizing water formation device configured to treat the raw water and form sterilizing water is disposed, a sterilizing water valve which is configured to open or close the sterilizing water flow path, and a clean water valve which is disposed in the clean water flow path and configured to adjust introduction of the raw water into the filter.

The controller may control the sterilizing water formation device, the sterilizing water valve, the clean water valve, and the drain valve to perform a sterilizing operation in which the sterilizing water is formed and passes through the clean water flow path and the drain flow path.

The controller may determine a cycle for repeating the sterilizing operation to be proportional to the remaining life of the filter.

In response to the flow rate in the clean water flow path being lower than or equal to a reference flow rate during drainage of water through the water discharge nozzle after an elapse of time corresponding to the determined cycle after the sterilizing operation is performed, the controller may re-perform the sterilizing operation.

In a case in which the controller receives information on an occurrence of contamination in the raw water as the external environment information through the communication device, the controller may perform the sterilizing operation or adjust the cycle for repeating the sterilizing operation to decrease.

The water purifier according to one embodiment may further include a display device, wherein the controller is configured to, in response to the remaining life of the filter being less than or equal to a first set value, control the display device to display a message requesting for replacement of the filter and, in response to the remaining life of the filter being less than or equal to a second set value which is lower than the first set value, block discharge of the clean water.

In response to the remaining life of the filter being less than or equal to a third set value which is higher than the first set value, the controller may control the display device to display the remaining life of the filter.

The controller may control the filter water passage valve to repeat opening and closing in a predetermined cycle.

In response to the remaining life of the filter being less than a predetermined value, the controller may stop controlling the filter water passage valve in the predetermined cycle.

By automatically cleaning the inside on the basis of external environment information, such as an installation environment and raw water contamination, or the remaining life of a filter, a water purifier according to one embodiment can keep the inside clean and provide clean potable water to a user and can suppress an unnecessary use of water and an overuse of a sterilizing water formation device during a cleaning process.

Embodiments described herein and configurations illustrated in the drawings are merely exemplary embodiments of the present invention.

Throughout the application, when a certain part is described as being "connected" to another part, both a case in which the certain part is indirectly connected to the other part as well as a case in which the certain part is directly connected to the other part are included therein, and the indirect connection includes a connection via a wireless network.

Terms used herein are for describing the embodiments and are not intended to limit and/or restrict the invention.

A singular expression includes a plural expression unless context clearly indicates otherwise. In the application, terms such as "include" or "have" should be understood as designating that features, number, steps, operations, elements, parts, or combinations thereof are present and not as precluding the possibility of the presence or addition of one or more other features, numbers, steps, operations, elements, parts, or combinations thereof in advance.

Terms including ordinals such as first and second may be used herein to describe various elements, but the elements are not limited by the terms. The terms are only used for the purpose of distinguishing one element from another element. For example, a first element may be referred to as a second element while not departing from the scope of the present invention, and likewise, a second element may also be referred to as a first element.

Terms such as "part," "-er/or," "block," "member," and "module" may refer to a unit of processing at least one function or operation. For example, the terms may refer to at least one hardware such as a field programmable gate array (FPGA) and an application-specific integrated circuit (ASIC), at least one software stored in a memory, or at least one process processed by a processor.

A reference numeral assigned to each step is used to identify each step and is not intended to represent an order of the steps. The steps may be performed in a different order from the stated order unless context clearly describes a specific order.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

<FIG> is a view illustrating a water purifier according to one embodiment.

Referring to <FIG>, a water purifier <NUM> according to one embodiment includes a raw water flow path <NUM> into which raw water such as tap water is introduced from the outside, a clean water flow path <NUM> connected to the raw water flow path <NUM> and having a water discharge nozzle <NUM> disposed at an end, a filter device <NUM> disposed in the clean water flow path <NUM> to filter the introduced raw water, a drain port <NUM> through which a liquid in the water purifier <NUM> is drained to the outside, and a drain flow path <NUM> branched off from the clean water flow path <NUM> between the filter device <NUM> and the water discharge nozzle <NUM> and connected to a drain port <NUM>. The flow paths disposed in the water purifier <NUM> may be formed by a plurality of pipes.

The raw water flow path <NUM> according to one embodiment may be connected to an external water pipe to allow the raw water to be introduced, and a raw water valve <NUM> configured to control introduction of the raw water and a pressure reducing valve <NUM> configured to reduce the pressure of the raw water may be disposed in the raw water flow path <NUM>.

Also, according to embodiments, a sediment filter configured to filter sediment included in the raw water or a high-turbidity filter configured to filter relatively large particles may be further disposed in the raw water flow path <NUM>.

The clean water flow path <NUM> is connected to the raw water flow path <NUM> and is configured to receive the raw water from the raw water flow path <NUM>, and a clean water valve <NUM> configured to control introduction of the raw water from the raw water flow path <NUM> may be disposed in the clean water flow path <NUM>.

Also, the filter device <NUM> configured to filter the raw water is disposed in the clean water flow path <NUM>. The filter device <NUM> may include a plurality of filters, e.g., a pre-carbon filter which adsorbs volatile substances such as chlorine and chlorine by-products from the raw water, a membrane filter which filters contaminants of very small sizes using a reverse osmotic pressure, and a post-carbon filter which affects a taste of discharged clean water.

Here, as the plurality of filters, the pre-carbon filter, the membrane filter, and the post-carbon filter may be connected in that order, and the raw water introduced into the filter device <NUM> may be filtered while sequentially passing through the pre-carbon filter, the membrane filter, and the post-carbon filter.

The above description of the types of filters of the filter device <NUM> is only an example that may be applied to an embodiment of the water purifier <NUM>, and embodiments of the water purifier <NUM> are not limited to the above example. Therefore, of course, types of filters other than those mentioned above may be provided by as many as the number other than three and in various other arrangements.

Also, the water discharge nozzle <NUM> is disposed at the end of the clean water flow path <NUM>, and a water discharge valve <NUM> configured to control a flow of clean water may be disposed on a front end of the water discharge nozzle <NUM>. That is, in response to the water discharge valve <NUM> being opened, clean water obtained by filtering in the filter device <NUM> may be discharged to the outside through the water discharge nozzle <NUM> disposed on a downstream end portion of the clean water flow path <NUM>.

Meanwhile, in an embodiment of the water purifier <NUM>, upstream and downstream sides and front and rear ends are defined according to directions in which water introduced into the water purifier <NUM> flows. A side close to a direction in which the raw water is introduced from the outside is the upstream side or the front end, and a side close to a direction in which clean water is discharged or drained to the outside is the downstream side or the rear end.

Also, according to embodiments, a flow rate sensor <NUM> configured to detect a flow rate in the clean water flow path <NUM> may be disposed in the clean water flow path <NUM> and may be disposed between the filter device <NUM> and the water discharge nozzle <NUM>. In a case in which a liquid flows in the clean water flow path <NUM> as in a case in which the water discharge valve <NUM> is opened and clean water is discharged to the outside through the water discharge nozzle <NUM>, the flow rate sensor <NUM> may output a detected value of the corresponding flow rate.

The drain flow path <NUM> is connected to a downstream side of the clean water flow path <NUM>. That is, the drain flow path <NUM> is branched off from the clean water flow path <NUM> between the filter device <NUM> and the water discharge nozzle <NUM> and connected to the drain port <NUM> to allow the liquid in the clean water flow path <NUM> to be drained to the outside.

A drain valve <NUM> configured to open or close the drain flow path <NUM> and control the flow of the clean water and a check valve (not illustrated) configured to prevent a backflow of the clean water may be disposed in the drain flow path <NUM>.

Since the drain flow path <NUM> is branched off from the clean water flow path <NUM>, in response to the drain valve <NUM> being opened, the clean water flowing in the clean water flow path <NUM> may be introduced into the drain flow path <NUM> and be discharged to the outside through the drain port <NUM> of the water purifier <NUM> that is connected to an end portion of the drain flow path <NUM>.

Meanwhile, the water purifier <NUM> according to one embodiment may further include a hot and cold water device <NUM> configured to provide hot water or cold water, and the hot and cold water device <NUM> may include a heat exchanger. The hot and cold water device <NUM> may be disposed downstream of the clean water flow path <NUM>. That is, the hot and cold water device <NUM> may be disposed in the clean water flow path <NUM> between the filter device <NUM> and the water discharge nozzle <NUM>.

In a case in which the water purifier <NUM> includes the hot and cold water device <NUM> according to embodiments, the water purifier <NUM> may further include a first transfer flow path <NUM> which includes one end connected to the hot and cold water device <NUM> and the other end connected to the drain flow path <NUM> and which is configured to transfer the clean water discharged from the hot and cold water device <NUM> to the drain flow path <NUM> and a second transfer flow path <NUM> which is branched off from the clean water flow path <NUM> between the hot and cold water device <NUM> and the water discharge nozzle <NUM> and connected to the drain flow path <NUM> to transfer the clean water in the clean water flow path <NUM> to the drain flow path <NUM>.

Also, according to embodiments, the water purifier <NUM> may further include a filter water passage flow path <NUM> which includes one end connected to the filter device <NUM> and the other end connected to the drain port <NUM> and through which raw water including impurities from the filter device <NUM> is drained.

Specifically, the filter water passage flow path <NUM> may be connected to a filter housing of the membrane filter of the filter device <NUM> and allows raw water cleaning the inside of the membrane filter to be drained to the drain port <NUM> by passing through the inside of the membrane filter.

Here, a filter water passage valve <NUM> configured to open or close the filter water passage flow path <NUM> to control the flow of the raw water passing through the membrane filter may be disposed in the filter water passage flow path <NUM>.

Also, according to embodiments, the water purifier <NUM> may further include a sterilizing water flow path <NUM> which includes one end connected to the raw water flow path <NUM> for the raw water to bypass the filter device <NUM> and the other end connected to the clean water flow path <NUM> between the filter device <NUM> and the water discharge nozzle <NUM> and which is configured to treat the raw water and form sterilizing water.

In this case, at least one of the clean water flow path <NUM> and the sterilizing water flow path <NUM> may be branched off from the raw water flow path <NUM>. For example, the clean water flow path <NUM> may be integrally connected to the raw water flow path <NUM>, and the sterilizing water flow path <NUM> may be formed to bypass from the raw water flow path <NUM>.

In the sterilizing water flow path <NUM>, a sterilizing water valve <NUM> configured to control introduction of the raw water from the raw water flow path <NUM> may be disposed, and a sterilizing water formation device <NUM> configured form the sterilizing water may be disposed.

For example, the sterilizing water formation device <NUM> may be implemented as an electrolytic device which electrolyzes water to form a sterilizing substance.

The sterilizing water formation device <NUM> which is implemented as an electrolytic device may include a plurality of plate-type electrodes. In response to the supply of current to the plurality of plate-type electrodes, chlorine included in water flowing between the plurality of plate-type electrodes may be electrolyzed, and a sterilizing substance having sterilizing power may be formed. For example, hypochlorous acid, which is a sterilizing substance, may be formed.

However, the sterilizing water formation device <NUM> is not limited to the above example, and any other known type of device that can form sterilizing water may be applied. For example, the sterilizing water formation device <NUM> may be provided as an ultraviolet (UV) lamp, a light emitting diode (LED) lamp, or the like.

The sterilizing water flow path <NUM> may be re-connected to the clean water flow path <NUM> at a rear end of the filter device <NUM> that is disposed in the clean water flow path <NUM>. That is, the sterilizing water flow path <NUM> may be re-connected to the clean water flow path <NUM> between the filter device <NUM> and the water discharge nozzle <NUM>.

According to embodiments, the water purifier <NUM> may include a main body (not illustrated). In this case, the water discharge nozzle <NUM> may be disposed outside the main body, and the filter device <NUM>, the flow paths, and the valves may be disposed inside the main body.

Also, according to embodiments, the water purifier <NUM> may be disposed on a lower portion of a sink in a kitchen, and the water discharge nozzle <NUM> may be disposed on an upper portion of the sink.

The arrangement of elements such as pipes and valves disposed inside the water purifier <NUM> has been described in detail above. Hereinafter, a home appliance <NUM> including the water purifier <NUM> will be described.

<FIG> is a view illustrating the home appliance <NUM> according to one embodiment.

Referring to <FIG>, the home appliance <NUM> according to one embodiment may include a main body <NUM> and may include the water purifier <NUM> which includes the water discharge nozzle <NUM> disposed outside the main body <NUM>.

For example, as illustrated in <FIG>, the home appliance <NUM> may correspond to a refrigerator. However, the type of the home appliance <NUM> is not limited to the above example and may, without limitations, include other types of home appliances, such as a carbonated water maker or a beer maker, as long as the home appliances perform an operation other than water purification.

Each of the filter device <NUM>, the flow paths <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>, the valves <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>, the sterilizing water formation device <NUM>, and the hot and cold water device <NUM> of the water purifier <NUM> may be disposed inside the main body <NUM> of the home appliance <NUM>, and a display device <NUM> may be disposed on an outer surface of the main body <NUM> of the home appliance <NUM>.

According to embodiments, the water purifier <NUM> described below may be provided as a separate device that only performs a water purification function or may be disposed in the home appliance <NUM> which performs a function other than the water purification function.

Hereinafter, functions of elements of the water purifier <NUM> will be described in detail.

<FIG> is a control block diagram of the water purifier <NUM> according to one embodiment.

Referring to <FIG>, the water purifier <NUM> according to one embodiment includes the flow rate sensor <NUM> configured to detect a flow rate in the clean water flow path <NUM>, an input device <NUM> configured to receive an input from a user, a communication device <NUM> configured to perform communication with an external electronic device, a storage device <NUM> configured to store various pieces of information necessary for control of the water purifier <NUM>, a controller <NUM> configured to automatically perform a cleaning operation on the basis of the remaining life of the filter device <NUM>, a valve <NUM> configured to control a flow of raw water, clean water, or sterilizing water inside the water purifier <NUM>, the sterilizing water formation device <NUM> configured to form sterilizing water, the hot and cold water device <NUM> configured to form hot water or cold water through a heat exchange with the clean water, and the display device <NUM> configured to display information on the cleaning operation.

The flow rate sensor <NUM> according to one embodiment may be disposed between the filter device <NUM> and the water discharge nozzle <NUM> and detect the flow rate in the clean water flow path <NUM>.

In a case in which a liquid flows in the clean water flow path <NUM> as in a case in which the water discharge valve <NUM> is opened and clean water is discharged to the outside through the water discharge nozzle <NUM>, the flow rate sensor <NUM> may output a detected value of the corresponding flow rate.

The input device <NUM> according to one embodiment may receive an input for water discharge from a user. To this end, the input device <NUM> may be disposed outside the water purifier <NUM> and may be implemented as a button, a touchpad, a lever, or the like.

The communication device <NUM> according to one embodiment may transmit and receive data to and from an external electronic device. The communication device <NUM> is configured to receive external environment information, such as information on the quality of raw water or information on an installation environment of the water purifier <NUM>, for example from an external electronic device.

To this end, the communication device <NUM> may perform wired communication or wireless communication with an external electronic device, and a known type of wired communication or wireless communication may be applied.

The storage device <NUM> according to one embodiment may be implemented as a known type of storage medium to store various pieces of information necessary for control of the water purifier <NUM>.

For example, the storage device <NUM> may store information on the correlation between the remaining life of the filter device <NUM> and a drainage reference time which is a reference for drainage of stagnant water, information on the correlation between the remaining life of the filter device <NUM> and a sterilizing operation cycle, information on the life of the filter device <NUM>, information on a point in time at which the filter device <NUM> has been replaced, and the like.

The controller <NUM> determines the remaining life of the filter device <NUM> on the basis of a point in time at which the filter device <NUM> has been replaced. Here, the point in time at which the filter device <NUM> has been replaced may be automatically updated at the time of replacing a filter of the filter device <NUM> and stored in the storage device <NUM> or may be input by a user through the input device <NUM> and stored in the storage device <NUM>.

According to embodiments, the controller <NUM> may determine a ratio (%) between a value obtained by subtracting, from the entire life of the filter device <NUM>, an amount of time elapsed from a point in time at which the filter device <NUM> has been replaced and the entire life of the filter device <NUM> as the remaining life of the filter device <NUM>.

Also, according to embodiments, the controller <NUM> may determine a clean water amount L which is obtained by subtracting, from an amount of available clean water in the filter device <NUM>, an amount of clean water that corresponds to an amount of time elapsed from a point in time at which the filter device <NUM> has been replaced as the remaining life of the filter device <NUM>, or may determine a ratio (%) between a clean water amount obtained by subtracting, from an amount of available clean water in the filter device <NUM>, an amount of clean water that corresponds to an amount of time elapsed from a point in time at which the filter device <NUM> has been replaced and the amount of available clean water in the filter device <NUM> as the remaining life of the filter device <NUM>. Here, the controller <NUM> may use a predetermined amount of clean water per hour to determine the amount of clean water that corresponds to the amount of time elapsed from the point in time at which the filter device <NUM> has been replaced, or may, on the basis of an output of the flow rate sensor <NUM>, determine the amount of clean water that corresponds to the amount of time elapsed from the point in time at which the filter device <NUM> has been replaced.

The controller <NUM> is configured to control the drain valve <NUM> to perform the cleaning operation on the basis of the external environment information received through the communication device <NUM> or on the basis of the remaining life of the filter device <NUM>.

Specifically, according to embodiments, in a case in which the controller <NUM> receives information on an occurrence of contamination in the raw water as the external environment information through the communication device <NUM>, the controller <NUM> may control the filter water passage valve <NUM> to open the filter water passage flow path <NUM> or may, according to embodiments, perform a sterilizing operation or adjust a cycle for repeating the sterilizing operation to decrease.

Also, in a case in which the controller <NUM> receives information on an installation environment indicating an uncontaminated area, in which the possibility of an occurrence of contamination in the raw water is low, as the external environment information through the communication device <NUM>, the controller <NUM> may control the filter water passage valve <NUM> to close the filter water passage flow path <NUM>. A configuration of performing the cleaning operation using the external environment information will be described again in detail below.

According to embodiments, the controller <NUM> may, on the basis of the remaining life of the filter device <NUM>, control the drain valve <NUM> to perform a stagnant water discharge operation in which stagnant water is discharged or control the drain valve <NUM> to perform a sterilizing operation in which the flow paths of the water purifier <NUM> are sterilized using sterilizing water.

In a case in which there is no user input through the input device <NUM> and thus water is not discharged through the water discharge nozzle <NUM>, a flow rate in the clean water flow path <NUM> that is calculated through the flow rate sensor <NUM> may be negligible or less than or equal to a predetermined value. In this case, stagnant water which is not able to be discharged may be formed in the flow paths inside the water purifier <NUM>, and contamination due to the accumulation of foreign matter, the growth of microorganisms, and the like may be accelerated with an increase in the stagnation time of the stagnant water in the water purifier <NUM>.

Here, the accumulation of foreign matter or the growth of microorganisms in the water purifier <NUM> may vary according to a point in time at which the filter device <NUM> has been replaced. That is, at the point in time at which the filter device <NUM> has been replaced, foreign matter or microorganisms may hardly be present in the filter device <NUM>, and thus the degree of contamination of the stagnant water may be low. On the other hand, after the filter device <NUM> is replaced, foreign matter or microorganisms may be accumulated in the filter device <NUM> as time passes, and thus the degree of contamination of the stagnant water may be high.

Therefore, according to embodiments, in response to the flow rate in the clean water flow path <NUM> being less than or equal to a predetermined value during a drainage reference time, the controller <NUM> may control the drain valve <NUM> to perform the stagnant water discharge operation in which the stagnant water is discharged.

Here, the controller <NUM> may determine the drainage reference time to be proportional to the remaining life of the filter device <NUM>. That is, the drainage reference time may shorten with a decrease in the remaining life of the filter device <NUM>. In other words, as time passes after the filter device <NUM> is replaced, the drainage reference time may shorten, and accordingly, the possibility that the stagnant water discharge operation is performed may increase.

That is, the controller <NUM> may adjust the drainage reference time to decrease with a decrease in the remaining life of the filter device <NUM>. Here, according to embodiments, the controller <NUM> may adjust the drainage reference time to decrease in stages according to the remaining life of the filter device <NUM>. This will be described again in detail below.

Also, according to embodiments, in a case of performing the stagnant water discharge operation, the controller <NUM> may change, in stages, a flow path through which the stagnant water is discharged.

Specifically, in a case in which a water discharge command is not input through the input device <NUM> during the drainage reference time and thus the flow rate in the clean water flow path <NUM> is less than or equal to a predetermined value, the controller <NUM> may control the drain valve <NUM> and the filter water passage valve <NUM> to drain the stagnant water in the clean water flow path <NUM> to the filter water passage flow path <NUM> for a predetermined amount of time and may control the drain valve <NUM> and the filter water passage valve <NUM> to drain the stagnant water in the clean water flow path <NUM> to the drain flow path <NUM> after the predetermined amount of time.

In this way, in the case of discharging the stagnant water, the water purifier <NUM> may change, in stages, a flow path through which the stagnant water is drained and thus prevent contamination at a front end of the membrane filter from spreading in a chain to the membrane filter and the post-carbon filter.

That is, the water purifier <NUM> may primarily discharge impurities at the front end of the membrane filter through the filter water passage flow path <NUM> connected to the membrane filter and then may secondarily discharge the stagnant water that has passed through the entire filter device <NUM> including the post-carbon filter.

Immediately after the filter device <NUM> is replaced, the accumulation of foreign matter or the growth of microorganisms is not enough to require sterilization, and thus the effect of sterilization is insignificant. In this case, considering that the life of the sterilizing water formation device <NUM> is limited, performing sterilization may be seen as repeating an unnecessary operation.

On the other hand, at a point in time at which the filter device <NUM> needs to be replaced due to an elapse of a large amount of time after the filter device <NUM> has been replaced, since the amount of foreign matter is large and an environment favorable for the growth of microorganisms is created, more frequent sterilization may be necessary.

Therefore, according to embodiments, the controller <NUM> may perform a sterilizing operation in which sterilizing water is formed in consideration of the remaining life of the filter device <NUM> and caused to pass through the flow paths inside the water purifier <NUM>. That is, the controller <NUM> may control the sterilizing water formation device <NUM>, the sterilizing water valve <NUM>, the clean water valve <NUM>, and the drain valve <NUM> to perform the sterilizing operation in which the sterilizing water is formed in consideration of the remaining life of the filter device <NUM> and passes through the clean water flow path <NUM> and the drain flow path <NUM>.

Specifically, the controller <NUM> may determine a cycle for repeating the sterilizing operation to be proportional to the remaining life of the filter device <NUM>. That is, the cycle of repetition of the sterilizing operation may shorten with a decrease in the remaining life of the filter device <NUM>. In other words, the cycle of repetition of the sterilizing operation may shorten as more time passes after the filter device <NUM> is replaced, and accordingly, the sterilizing operation may be repeated in a shorter cycle with a decrease in the remaining life of the filter device <NUM>.

Here, according to embodiments, the controller <NUM> may adjust the determined cycle of repetition of the sterilizing operation on the basis of information on the quality of raw water that is received through the communication device <NUM>.

That is, the controller <NUM> may adjust the cycle of repetition of the sterilizing operation to shorten with a decrease in the water quality indicated by the information on the quality of raw water (e.g., nephelometric turbidity unit (NTU)).

In a case in which a cleaning operation such as the stagnant water discharge operation or the sterilizing operation is performed, the controller <NUM> according to one embodiment may control the display device <NUM> to display information on the cleaning operation.

Here, the information on the cleaning operation may include information related to the cleaning operation, such as whether the cleaning operation is performed, progress of the cleaning operation, and history of performing the cleaning operation.

Also, the controller <NUM> may control the communication device <NUM> to transmit the information on the cleaning operation to an external electronic device, and in this case, the external electronic device may display the information on the cleaning operation through a display.

The controller <NUM> may include a program for performing the operations described above or operations to be described below, at least one memory configured to store various data necessary for running the program, and at least one processor configured to run a stored program.

The valve <NUM> according to one embodiment may, by being opened or closed according to control by the controller <NUM>, control a flow of raw water, clean water, or sterilizing water in a flow path in which the valve <NUM> is disposed.

According to embodiments, the valve <NUM> may include the raw water valve <NUM> disposed in the raw water flow path <NUM>, the drain valve <NUM> disposed in the drain flow path <NUM>, the filter water passage valve <NUM> disposed in the filter water passage flow path <NUM>, the sterilizing water valve <NUM> disposed in the sterilizing water flow path <NUM>, the clean water valve <NUM> disposed in the clean water flow path <NUM>, and the water discharge valve <NUM> disposed on the front end of the water discharge nozzle <NUM>. The control of the valve <NUM> will be described again in detail below.

The sterilizing water formation device <NUM> according to one embodiment may be disposed in the sterilizing water flow path <NUM> and treat introduced raw water to form sterilizing water.

According to embodiments, the sterilizing water formation device <NUM> may be implemented as an electrolytic device which electrolyzes raw water to form a sterilizing substance. According to embodiments, the sterilizing water formation device <NUM> may be provided as a UV lamp, an LED lamp, or the like.

The hot and cold water device <NUM> according to one embodiment may include a heat exchanger and be disposed downstream of the clean water flow path <NUM> and may provide hot water or cold water through a heat exchange with clean water on the basis of a user input through the input device <NUM>.

That is, the hot and cold water device <NUM> may be disposed in the clean water flow path <NUM> between the filter device <NUM> and the water discharge nozzle <NUM> and receive clean water from the filter device <NUM> and may convert the clean water to hot water or cold water through the heat exchange and transfer the hot water or cold water to the water discharge nozzle <NUM>.

The display device <NUM> according to one embodiment may display information on a cleaning operation such as the stagnant water discharge operation or the sterilizing operation. To this end, according to embodiments, the display device <NUM> may include a known type of display panel or include an LED lamp.

Corresponding to performance of the elements of the water purifier <NUM> illustrated in <FIG>, at least one element may be added or omitted. Also, it should be easily understood by those of ordinary skill in the art that positions of the elements may be changed according to the performance or structure of the system.

The elements of the water purifier <NUM> have been described in detail above. Hereinafter, the water purifier <NUM> performing a cleaning operation will be described in detail.

<FIG> is a view illustrating the correlation between the remaining life of the filter device <NUM> and the drainage reference time according to one embodiment, <FIG> is a view illustrating a case in which the water purifier <NUM> discharges stagnant water through the filter water passage flow path according to one embodiment, <FIG> is a view illustrating the membrane filter of the filter device <NUM> according to one embodiment, and <FIG> is a view illustrating a case in which the water purifier <NUM> discharges stagnant water through the drain flow path according to one embodiment.

In a case in which there is no user input and thus clean water is not discharged through the water discharge nozzle <NUM>, a flow rate in the clean water flow path <NUM> that is calculated through the flow rate sensor <NUM> may be negligible or less than or equal to a predetermined value. In this case, stagnant water which is not able to be discharged may be formed in the flow paths inside the water purifier <NUM>, and contamination due to the accumulation of foreign matter, the growth of microorganisms, and the like may be accelerated with an increase in the stagnation time of the stagnant water in the water purifier <NUM>.

Therefore, according to embodiments, the controller <NUM> may adjust a cycle of performing the stagnant water discharge operation on the basis of the remaining life of the filter device <NUM>.

Specifically, according to embodiments, in response to the flow rate in the clean water flow path <NUM> being less than or equal to a predetermined value during a drainage reference time, the controller <NUM> may determine that stagnant water is formed due to the absence of a user input for water discharge during the drainage reference time and may control the drain valve <NUM> to perform the stagnant water discharge operation for discharging the stagnant water.

Here, the controller <NUM> may determine the drainage reference time to be proportional to the remaining life of the filter device <NUM>. That is, the controller <NUM> may adjust the drainage reference time to decrease with a decrease in the remaining life of the filter device <NUM>.

For example, on the basis of the information on the correlation between the remaining life of the filter device <NUM> and the drainage reference time that is illustrated in <FIG>, the controller <NUM> may determine the drainage reference time as <NUM> hours in a case in which the remaining life of the filter device <NUM> is <NUM>% or more, may determine the drainage reference time as <NUM> hours in a case in which the remaining life of the filter device <NUM> is <NUM>% or more and less than <NUM>%, and may determine the drainage reference time as <NUM> hours in a case in which the remaining life of the filter device <NUM> is less than <NUM>%. In this way, according to embodiments, the controller <NUM> may adjust the drainage reference time to decrease in stages according to the remaining life of the filter device <NUM>.

That is, the drainage reference time may shorten with a decrease in the remaining life of the filter device <NUM>. In other words, the drainage reference time may shorten as more time passes after the filter device <NUM> is replaced, and accordingly, the possibility that the stagnant water discharge operation is performed may increase.

As described above, the degree of contamination of the stagnant water may vary according to a period of use of the filter device <NUM>. Therefore, taking into consideration that the degree of contamination of the stagnant water increases as more time passes from a point in time at which the filter device <NUM> has been replaced, the water purifier <NUM> may determine the drainage reference time to shorten to discharge the stagnant water more frequently with a decrease in the remaining life of the filter device <NUM>.

Here, according to embodiments, in a case of performing the stagnant water discharge operation, the controller <NUM> may change, in stages, a flow path through which the stagnant water is discharged.

As illustrated in <FIG>, the controller <NUM> may open the raw water valve <NUM> and the filter water passage valve <NUM> to drain the stagnant water to the filter water passage flow path <NUM> and may close the drain valve <NUM>, the sterilizing water valve <NUM>, and the clean water valve <NUM>. In this case, the stagnant water stagnating in the raw water flow path <NUM> and the clean water flow path <NUM> may be discharged through the drain port <NUM> on the basis of the pressure of the raw water.

Here, the stagnant water discharged to the filter water passage flow path <NUM> may pass through the membrane filter of the filter device <NUM> and thus remove impurities from the membrane filter.

Specifically, as illustrated in <FIG>, a membrane filter <NUM> of the filter device <NUM> includes a filter cap <NUM> and a filter housing <NUM>.

Here, the filter cap <NUM> may have the shape of a cap which is formed at one side of the membrane filter <NUM> and has an inner space formed therein, may include through-holes for connection to each of the flow paths, and may include a raw water inlet <NUM>, a clean water outlet <NUM>, and a drain outlet <NUM> as the through-holes.

The raw water inlet <NUM> may be provided to be connected to the clean water flow path <NUM> at the raw water flow path <NUM> side and allow introduction of raw water, and the clean water outlet <NUM> may be provided to be connected to the clean water flow path <NUM> at the water discharge nozzle <NUM> side and allow discharge of clean water obtained by filtering in the filter device. The drain outlet <NUM> may be provided to be connected to the filter water passage flow path <NUM> and, during the discharge of stagnant water, discharge stagnant water including contaminants to the outside.

Also, the filter housing <NUM> includes an outer housing <NUM> and an inner housing <NUM>, and the outer housing <NUM> forms an exterior of the membrane filter <NUM>.

The inner housing <NUM> may be formed to be spaced apart from the outer housing <NUM>, may have an accommodation space formed therein, and may include a filter body <NUM> disposed in the accommodation space to filter raw water.

As the stagnant water discharge operation is performed, in a case in which the filter water passage valve <NUM> is opened, raw water may be introduced through the raw water inlet <NUM> of the membrane filter <NUM> and remove impurities on an outer surface of the filter body <NUM>.

The water including impurities of the filter body <NUM> may flow from the accommodation space of the inner housing <NUM> to an opening below the inner housing <NUM>, and the stagnant water that has passed through the opening may flow upward again along a separation space between the inner housing <NUM> and the outer housing <NUM>. In this way, the stagnant water may be discharged to the outside of the membrane filter <NUM> through the drain outlet <NUM>, may flow to the filter water passage flow path <NUM> connected to the drain outlet <NUM>, and may be discharged to the outside through the drain port <NUM>.

In this way, in the case of performing the stagnant water discharge operation, the controller <NUM> may open the filter water passage valve <NUM> for a predetermined amount of time to allow the stagnant water to pass through the membrane filter <NUM>, remove impurities, and be transferred to the drain port <NUM> through the filter water passage flow path <NUM>.

Then, as illustrated in <FIG>, the controller <NUM> closes the filter water passage valve <NUM> and opens the raw water valve <NUM>, the drain valve <NUM>, and the clean water valve <NUM> to allow the stagnant water in the clean water flow path <NUM> to flow to the drain flow path <NUM> and be discharged. Here, the controller <NUM> may close the water discharge valve <NUM> and may, according to embodiments, also close the sterilizing water valve <NUM>.

According to embodiments, in a case in which the water purifier <NUM> further includes the hot and cold water device <NUM>, the stagnant water that has passed through the hot and cold water device <NUM> may flow to the drain flow path <NUM> through the first transfer flow path <NUM> and the second transfer flow path <NUM>.

In this way, in the case of discharging the stagnant water, the water purifier <NUM> may change, in stages, a flow path through which the stagnant water is drained and thus prevent contamination at a front end of the membrane filter <NUM> from spreading in a chain to the membrane filter <NUM> and the post-carbon filter.

That is, the water purifier <NUM> may primarily discharge impurities at the front end of the membrane filter <NUM> through the filter water passage flow path <NUM> connected to the membrane filter <NUM> and then may secondarily discharge the stagnant water that has passed through the entire filter device <NUM> including the post-carbon filter.

<FIG> is a view illustrating the correlation between the remaining life of the filter device <NUM> and a sterilizing operation cycle according to one embodiment, <FIG> is a view illustrating a case in which the water purifier <NUM> forms sterilizing water during the sterilizing operation according to one embodiment, and <FIG> is a view illustrating a case in which the water purifier <NUM> rinses out residual sterilizing water during the sterilizing operation according to one embodiment.

On the other hand, at a point in time at which the filter device <NUM> needs to be replaced due to an elapse of a large amount of time after the filter device <NUM> is replaced, since the amount of foreign matter is large and an environment favorable for the growth of microorganisms is created, more frequent sterilization may be necessary.

Accordingly, according to embodiments, the controller <NUM> may determine a cycle for repeating the sterilizing operation on the basis of the remaining life of the filter device <NUM>. Specifically, the controller <NUM> may determine the cycle of repetition of the sterilizing operation to be proportional to the remaining life of the filter device <NUM>.

For example, on the basis of the information on the correlation between the remaining life of the filter device <NUM> and the sterilizing operation cycle that is illustrated in <FIG>, the controller <NUM> may determine the sterilizing operation cycle as <NUM> days in a case in which the remaining life of the filter device <NUM> is <NUM>% or more, may determine the sterilizing operation cycle as <NUM> days in a case in which the remaining life of the filter device <NUM> is <NUM>% or more and less than <NUM>%, and may determine the sterilizing operation cycle as <NUM> days in a case in which the remaining life of the filter device <NUM> is less than <NUM>%.

That is, the cycle of repetition of the sterilizing operation may shorten with a decrease in the remaining life of the filter device <NUM>. In other words, the cycle of repetition of the sterilizing operation may shorten as more time passes after the filter device <NUM> is replaced, and accordingly, the sterilizing operation may be repeated in a shorter cycle with a decrease in the remaining life of the filter device <NUM>.

In this way, the controller <NUM> may control the sterilizing water formation device <NUM>, the sterilizing water valve <NUM>, the clean water valve <NUM>, and the drain valve <NUM> to perform the sterilizing operation in which the sterilizing water is formed in consideration of the remaining life of the filter device <NUM> and passes through the clean water flow path <NUM> and the drain flow path <NUM>.

Here, the sterilizing operation may be divided into a first sterilizing operation in which the sterilizing water is formed and a second sterilizing operation in which the residual sterilizing water is rinsed out.

Specifically, as illustrated in <FIG>, the controller <NUM> may open the raw water valve <NUM>, the sterilizing water valve <NUM>, and the drain valve <NUM> and turn on the sterilizing water formation device <NUM> so that raw water bypasses the filter device <NUM> and passes through the sterilizing water flow path <NUM> and thus sterilizing water is formed. Here, the controller <NUM> may close the clean water valve <NUM>.

The formed sterilizing water may sterilize the clean water flow path <NUM> and the drain flow path <NUM>, and according to embodiments, the controller <NUM> may, after the sterilizing water is formed, close the drain valve <NUM> for a predetermined amount of time to allow the formed sterilizing water to stay in the flow paths <NUM> and <NUM> for the predetermined amount of time and then open the drain valve <NUM> again.

Then, as illustrated in <FIG>, the controller <NUM> may close the sterilizing water valve <NUM> and open the raw water valve <NUM>, the clean water valve <NUM>, and the drain valve <NUM> to rinse out the sterilizing water remaining in the flow paths <NUM> and <NUM> using raw water or clean water and to allow clean water including the sterilizing water to be discharged through the drain port <NUM>.

As described above, the controller <NUM> may perform the sterilizing operation on the basis of a repetition cycle thereof which is determined on the basis of the remaining life of the filter device <NUM>.

That is, in a case in which an amount of time that corresponds to the determined repetition cycle passes after the sterilizing operation is performed, the controller <NUM> may automatically re-perform the sterilizing operation.

However, according to embodiments, the controller <NUM> may further consider whether the flow rate in the clean water flow path <NUM> has decreased, in addition to considering the repetition cycle determined on the basis of the remaining life of the filter device <NUM>, to determine whether to perform the sterilizing operation.

Specifically, in response to the flow rate in the clean water flow path <NUM> being lower than or equal to a reference flow rate during drainage of water through the water discharge nozzle <NUM> after an elapse of the time corresponding to the determined repetition cycle after the sterilizing operation is performed, the controller <NUM> may re-perform the sterilizing operation.

That is, in a case in which a new repetition cycle comes after the sterilizing operation is performed, the controller <NUM> may determine whether the flow rate in the clean water flow path <NUM> at the time the clean water is drained through the water discharge nozzle <NUM> is lower than or equal to a reference flow rate and may re-perform the sterilizing operation in response to the flow rate in the clean water flow path <NUM> becoming lower than or equal to the reference flow rate.

In this way, according to embodiments, the controller <NUM> may perform the sterilizing operation in a case in which the flow rate of the clean water in the clean water flow path <NUM> decreases due to the accumulation of foreign matter in the filter device <NUM> and the flow paths <NUM> and <NUM> and thus may ensure the flow rate of the clean water through foreign matter removal.

Also, according to embodiments, in a case in which the controller <NUM> receives information on an occurrence of contamination in the raw water as the external environment information through the communication device <NUM>, the controller <NUM> may perform the sterilizing operation or adjust the cycle for repeating the sterilizing operation to decrease.

In this way, even in a case in which biological contamination such as green algae formation occurs in the raw water, the water purifier <NUM> may provide the sterilizing operation immediately or repeat the sterilizing operation in a short cycle, thus keeping the inside of the water purifier <NUM> clean.

<FIG> is a view illustrating a case in which the water purifier <NUM> controls the filter water passage valve <NUM> according to one embodiment.

Referring to <FIG>, in a case in which the controller <NUM> according to one embodiment receives information on an occurrence of contamination in the raw water from an external server (not illustrated) through the communication device <NUM>, the controller <NUM> may control the filter water passage valve <NUM> to open the filter water passage flow path <NUM>.

Specifically, in a case in which the controller <NUM> receives information on an occurrence of contamination in the raw water (e.g., an occurrence of rust in tap water, an occurrence of green algae in a water supply source, introduction of contaminants into tap water, etc.), from an external server managing raw water such as tap water (e.g., a water resources corporation server), the controller <NUM> may open the filter water passage valve <NUM> to allow the raw water to pass through the filter water passage flow path <NUM>.

In this way, in response to receiving information on contamination in the raw water, the water purifier <NUM> may open the filter water passage valve <NUM> so that impurities accumulated in the membrane filter <NUM> of the filter device <NUM> are removed by the raw water, and in this way, the water purifier <NUM> can prevent a flow rate decrease and water purification performance drop which may occur due to the filter device <NUM> being blocked.

Also, the controller <NUM> according to one embodiment may control the filter water passage valve <NUM> to repeat opening and closing in a predetermined cycle. That is, according to embodiments, the controller <NUM> may repeat opening and closing of the filter water passage valve <NUM> in a predetermined cycle to periodically remove impurities accumulated in the membrane filter <NUM> of the filter device <NUM>. In this way, since the impurities in the membrane filter <NUM> may be periodically removed, the life of the filter device <NUM> can be extended.

However, in a situation in which the flow rate of clean water which passes through the filter device <NUM> and is transferred to the water discharge nozzle <NUM> decreases according to the life of the filter device <NUM>, the controller <NUM> may, in response to the remaining life of the filter device <NUM> being less than a predetermined value (e.g., <NUM>%), stop controlling the filter water passage valve <NUM> in the predetermined cycle and close the filter water passage valve <NUM> in order to prevent a further decrease in the flow rate due to the filter water passage valve <NUM> being opened. In this way, the water purifier <NUM> may ensure the flow rate of the clean water even in a situation in which the remaining life of the filter device <NUM> is shortened.

Also, according to embodiments, the water purifier <NUM> may control the filter water passage valve <NUM> in consideration of an installation environment of the water purifier <NUM>. That is, the controller <NUM> may control the filter water passage valve <NUM> on the basis of information on the installation environment of the water purifier <NUM> that is input by a user through the input device <NUM> or received through the communication device <NUM>. Here, the installation environment may correspond to an environment of an area around the position at which the water purifier <NUM> is installed.

Specifically, in a case in which the installation environment of the water purifier <NUM> corresponds to a contamination-prone area where contamination of raw water may occur, such as a densely populated area such as a large city or an area of concern for pollution such as an industrial district, as described above, the controller <NUM> may control the filter water passage valve <NUM> in response to receiving information on an occurrence of contamination or may open or close the filter water passage valve <NUM> according to the life of the filter device <NUM>.

Also, in a case in which the installation environment of the water purifier <NUM> corresponds to an uncontaminated area in which the possibility of contamination of raw water is low, such as a mountainous area, the controller <NUM> may close the filter water passage valve <NUM> from the beginning.

In this way, by utilizing the filter water passage flow path <NUM> adaptively according to the installation environment, the water purifier <NUM> can effectively prevent contamination of the water purifier <NUM>.

<FIG> is a view illustrating a case in which the water purifier <NUM> displays progress of a drainage operation through the display device <NUM> according to one embodiment.

Referring to <FIG>, in a case in which a cleaning operation such as the stagnant water discharge operation or the sterilizing operation is performed, the controller <NUM> according to one embodiment may control the display device <NUM> to display cleaning operation information <NUM>.

Here, the cleaning operation information <NUM> may include information related to the cleaning operation, such as whether the cleaning operation is performed, progress of the cleaning operation, and history of performing the cleaning operation.

<FIG> is a view for describing a case in which the water purifier <NUM> operates according to the remaining life of the filter device <NUM> according to one embodiment, <FIG> is a view illustrating a case in which the water purifier <NUM> provides a notification of the remaining life of the filter device <NUM> according to one embodiment, and <FIG> is a view illustrating a case in which the water purifier <NUM> provides a notification of a need to replace the filter device <NUM> according to one embodiment.

Referring to <FIG>, in response to the remaining life of the filter device <NUM> being less than or equal to a first set value (e.g., <NUM>%), the controller <NUM> according to one embodiment may control the display device <NUM> to display the remaining life of the filter device <NUM>.

That is, in response to the remaining life of the filter device <NUM> being less than or equal to the first set value (e.g., <NUM>%), the water purifier <NUM> may, as illustrated in <FIG>, display through the display device <NUM> a message <NUM> indicating the remaining life of the filter device <NUM> (e.g., <NUM>%).

In this way, a user may recognize in advance that not much remaining life of the filter device <NUM> is left and may prepare for replacement of the filter device <NUM> before no more remaining life of the filter device <NUM> is left.

Here, according to embodiments, in a situation in which the remaining life of the filter device <NUM> is decreased to less than or equal to the first set value, the water purifier <NUM> may display through the display device <NUM> the message <NUM> indicating the remaining life of the filter device <NUM>, every time the remaining life of the filter device <NUM> decreases by a predetermined percentage (e.g., <NUM>%).

According to embodiments, the water purifier <NUM> may always display the remaining life of the filter device <NUM>, regardless of the actual value of the remaining life of the filter device <NUM>.

Also, according to embodiments, in response to the remaining life of the filter device <NUM> being less than or equal to the first set value (e.g., <NUM>%), the water purifier <NUM> may control the communication device <NUM> to transmit to a user terminal (not illustrated) a message indicating the remaining life of the filter device <NUM>.

Also, in response to the remaining life of the filter device <NUM> being less than or equal to a second set value (e.g., <NUM>%), the controller <NUM> according to one embodiment may control the display device <NUM> to display a message notifying a user that replacement of the filter device <NUM> is necessary. Here, the second set value may be a value lower than the first set value.

That is, in response to the remaining life of the filter device <NUM> being less than or equal to the second set value (e.g., <NUM>%), the water purifier <NUM> may, as illustrated in <FIG>, display through the display device <NUM> a message <NUM> notifying a user that replacement of the filter device <NUM> is necessary.

In this way, a user may intuitively recognize that replacement of the filter device <NUM> is necessary and may prepare for the replacement of the filter device <NUM> before no more remaining life of the filter device <NUM> is left.

Here, according to embodiments, in a case in which no more remaining life of the filter device <NUM> is left, the water purifier <NUM> may display through the display device <NUM> a message indicating that the filter device <NUM> needs to be replaced immediately.

Also, according to embodiments, in response to the remaining life of the filter device <NUM> being less than or equal to the second set value (e.g., <NUM>%), the water purifier <NUM> may control the communication device <NUM> to transmit to the user terminal a message notifying a user that replacement of the filter device <NUM> is necessary.

Also, in response to the remaining life of the filter device <NUM> being less than or equal to a third set value (e.g., -<NUM>%), the controller <NUM> according to one embodiment may block water discharge. Here, the third set value may be a value lower than the second set value and may be a value less than or equal to <NUM>%.

That is, in response to the remaining life of the filter device <NUM> being less than or equal to the third set value, the water purifier <NUM> may determine that the filter device <NUM> is not able to fulfill its filtering function anymore and may control a valve to block water discharge. For example, the water purifier <NUM> may control at least one of the water discharge valve <NUM>, the raw water valve <NUM>, and the clean water valve <NUM> to block water discharge.

Also, in a case in which the controller <NUM> according to one embodiment receives information on an occurrence of contamination in the raw water as the external environment information through the communication device <NUM>, the controller <NUM> may block water discharge.

That is, in response to recognizing that contamination has occurred in the raw water, the water purifier <NUM> may determine that clean water is not able to be discharged anymore and may control a valve to block discharge of clean water. For example, the water purifier <NUM> may control at least one of the water discharge valve <NUM>, the raw water valve <NUM>, and the clean water valve <NUM> to block discharge of clean water.

However, according to embodiments, the water purifier <NUM> may control a normal open type high pressure solenoid (NOS) valve, in addition to the water discharge valve <NUM>, the raw water valve <NUM>, and the clean water valve <NUM>, to block discharge of clean water.

Hereinafter, an embodiment relating to a method of controlling the water purifier <NUM> according to one aspect will be described. The water purifier <NUM> according to the above-described embodiment may be used in the method of controlling the water purifier <NUM>. Therefore, the content described above with reference to <FIG> may identically apply to the method of controlling the water purifier <NUM>.

<FIG> is a flowchart of a case in which the drainage operation is performed in the method of controlling the water purifier <NUM> according to one embodiment.

Referring to <FIG>, the water purifier <NUM> according to one embodiment may determine the remaining life of the filter device <NUM> on the basis of a point in time at which the filter device <NUM> has been replaced (<NUM>).

Also, according to embodiments, the controller <NUM> may determine a clean water amount L which is obtained by subtracting, from an amount of available clean water in the filter device <NUM>, an amount of clean water that corresponds to an amount of time elapsed from a point in time at which the filter device <NUM> has been replaced as the remaining life of the filter device <NUM>, or may determine a ratio (%) between a clean water amount obtained by subtracting, from an amount of available clean water in the filter device <NUM>, an amount of clean water that corresponds to an amount of time elapsed from a point in time at which the filter device <NUM> has been replaced and the amount of available clean water in the filter device <NUM> as the remaining life of the filter device <NUM>.

The water purifier <NUM> according to one embodiment may determine the drainage reference time to be proportional to the remaining life of the filter device <NUM> (<NUM>).

That is, the drainage reference time may shorten with a decrease in the remaining life of the filter device <NUM>. In other words, as time passes after the filter device <NUM> is replaced, the drainage reference time may shorten, and accordingly, the possibility that the stagnant water discharge operation is performed may increase.

In a case in which the flow rate in the clean water flow path <NUM> is less than or equal to a predetermined value during the drainage reference time (yes in <NUM>), the water purifier <NUM> according to one embodiment may control the drain valve <NUM> and the filter water passage valve <NUM> to drain the stagnant water in the clean water flow path <NUM> to the filter water passage flow path <NUM> (<NUM>).

Specifically, the controller <NUM> may open the raw water valve <NUM> and the filter water passage valve <NUM> to drain the stagnant water to the filter water passage flow path <NUM> and may close the drain valve <NUM>, the sterilizing water valve <NUM>, and the clean water valve <NUM>. In this case, the stagnant water stagnating in the raw water flow path <NUM> and the clean water flow path <NUM> may be discharged through the drain port <NUM> on the basis of the pressure of the raw water. Here, the stagnant water discharged to the filter water passage flow path <NUM> may pass through the membrane filter of the filter device <NUM> and thus remove impurities from the membrane filter.

In a case in which a predetermined amount of time passes after controlling the drain valve <NUM> and the filter water passage valve <NUM> to drain the stagnant water in the clean water flow path <NUM> to the filter water passage flow path <NUM> (yes in <NUM>), the water purifier <NUM> according to one embodiment may control the drain valve <NUM> and the filter water passage valve <NUM> to drain the stagnant water in the clean water flow path <NUM> to the drain flow path <NUM> (<NUM>).

Specifically, the controller <NUM> closes the filter water passage valve <NUM> and opens the raw water valve <NUM>, the drain valve <NUM>, and the clean water valve <NUM> to allow the stagnant water in the clean water flow path <NUM> to flow to the drain flow path <NUM> and be discharged. Here, the controller <NUM> may close the water discharge valve <NUM> and may, according to embodiments, also close the sterilizing water valve <NUM>.

In this way, in the case of discharging the stagnant water, the water purifier <NUM> may change, in stages, a flow path through which the stagnant water is drained and thus prevent contamination at the front end of the membrane filter <NUM> from spreading in a chain to the membrane filter <NUM> and the post-carbon filter.

<FIG> is a flowchart of a case in which the sterilizing operation is performed in the method of controlling the water purifier <NUM> according to one embodiment.

Referring to <FIG>, the water purifier <NUM> according to one embodiment may determine the remaining life of the filter device <NUM> on the basis of a point in time at which the filter device <NUM> has been replaced (<NUM>) and may determine the cycle of repetition of the sterilizing operation to be proportional to the remaining life of the filter device <NUM> (<NUM>).

Accordingly, according to embodiments, the controller <NUM> may determine the cycle for repeating the sterilizing operation on the basis of the remaining life of the filter device <NUM>. Specifically, the controller <NUM> may determine the cycle of repetition of the sterilizing operation to be proportional to the remaining life of the filter device <NUM>.

In a case in which a new repetition cycle comes after the sterilizing operation is performed (yes in <NUM>), the water purifier <NUM> according to one embodiment may control the sterilizing water formation device <NUM>, the sterilizing water valve <NUM>, the clean water valve <NUM>, and the drain valve <NUM> to perform the sterilizing operation (<NUM>).

<FIG> is a flowchart of a case in which the filter water passage valve <NUM> is controlled on the basis of data from an external server in the method of controlling the water purifier <NUM> according to one embodiment.

Referring to <FIG>, in response to receiving information on an occurrence of contamination in the raw water from an external server (yes in <NUM>), the water purifier <NUM> according to one embodiment may open the filter water passage valve <NUM> (<NUM>).

That is, in a case in which the controller <NUM> receives information on an occurrence of contamination in the raw water from an external server (not illustrated) through the communication device <NUM>, the controller <NUM> may control the filter water passage valve <NUM> to open the filter water passage flow path <NUM>.

Also, in response to receiving information on an occurrence of contamination in the raw water from an external server (yes in <NUM>), the water purifier <NUM> according to one embodiment may perform the sterilizing operation or adjust the cycle of repetition of the sterilizing operation to decrease (<NUM>).

<FIG> is a flowchart of a case in which the filter water passage valve <NUM> is controlled according to the remaining life of the filter device <NUM> in the method of controlling the water purifier <NUM> according to one embodiment.

Referring to <FIG>, the water purifier <NUM> according to one embodiment may control the filter water passage valve <NUM> to repeat opening and closing in a predetermined cycle (<NUM>).

That is, according to embodiments, the controller <NUM> may repeat opening and closing of the filter water passage valve <NUM> in a predetermined cycle to periodically remove impurities accumulated in the membrane filter <NUM> of the filter device <NUM>. In this way, since the impurities in the membrane filter <NUM> may be periodically removed, the life of the filter device <NUM> can be extended.

However, in a situation in which the flow rate of clean water which passes through the filter device <NUM> and is transferred to the water discharge nozzle <NUM> decreases according to the life of the filter device <NUM>, the water purifier <NUM> may, in response to the remaining life of the filter device <NUM> being less than a predetermined value (e.g., <NUM>%) (yes in <NUM>), stop controlling the filter water passage valve <NUM> in the predetermined cycle (<NUM>) in order to prevent a further decrease in the flow rate due to the filter water passage valve <NUM> being opened. That is, the water purifier <NUM> may close the filter water passage valve <NUM>. In this way, the water purifier <NUM> may ensure the flow rate of the clean water even in a situation in which the remaining life of the filter device <NUM> is shortened.

<FIG> is a flowchart of a case in which an operation is performed according to the remaining life of the filter device <NUM> in the method of controlling the water purifier <NUM> according to one embodiment.

Referring to <FIG>, the water purifier <NUM> according to one embodiment may determine the remaining life of the filter device <NUM> on the basis of a point in time at which the filter device <NUM> has been replaced (<NUM>) and may, in response to the remaining life of the filter device <NUM> being less than or equal to a first set value (e.g., <NUM>%) (yes in <NUM>), display the remaining life of the filter device <NUM> (<NUM>).

That is, in response to the remaining life of the filter device <NUM> being less than or equal to the first set value (e.g., <NUM>%), the water purifier <NUM> may display through the display device <NUM> the message <NUM> indicating the remaining life of the filter device <NUM> (e.g., <NUM>%).

Also, in response to the remaining life of the filter device <NUM> being less than or equal to a second set value (e.g., <NUM>%) (yes in <NUM>), the water purifier <NUM> may display a message indicating that replacement of the filter device <NUM> is necessary (<NUM>). Here, the second set value may be a value lower than the first set value.

That is, in response to the remaining life of the filter device <NUM> being less than or equal to the second set value (e.g., <NUM>%), the water purifier <NUM> may display through the display device <NUM> the message <NUM> notifying that replacement of the filter device <NUM> is necessary.

Also, in response to the remaining life of the filter device <NUM> being less than or equal to a third set value (e.g., -<NUM>%) (yes in <NUM>), the water purifier <NUM> may block discharge of clean water (<NUM>). Here, the third set value may be a value lower than the second set value and may be a value less than or equal to <NUM>%.

<FIG> is a flowchart of a case in which discharge of clean water is blocked according to external environment information in the method of controlling the water purifier <NUM> according to one embodiment.

Referring to <FIG>, in response to receiving information on an occurrence of contamination in the raw water from an external server (yes in <NUM>), the water purifier <NUM> according to one embodiment may block discharge of clean water (<NUM>).

Meanwhile, the embodiments disclosed herein may be implemented in the form of a recording medium that stores computer-executable instructions. The instructions may be stored in the form of a program code, and when executed by a processor, the instructions may generate a program module and perform operations of the embodiments disclosed herein. The recording medium may be implemented as a computer-readable recording medium.

The computer-readable recording medium may include all types of recording media in which computer-decodable instructions are stored. Examples of the computer-readable recording medium may include a read-only memory (ROM), a random access memory (RAM), a magnetic tape, a magnetic disk, a flash memory, and an optical data storage.

Claim 1:
A water purifier (<NUM>) comprising:
a communication device (<NUM>) to receive external environment information, which is information on the quality of raw water or information on an installation environment of the water purifier (<NUM>), being used to perform a cleaning operation of the water purifier (<NUM>);
a raw water flow path (<NUM>) into which raw water is introduced from the outside;
a clean water flow path (<NUM>) connected to the raw water flow path (<NUM>) and having a water discharge nozzle (<NUM>) disposed at an end thereof;
a filter device (<NUM>) disposed in the clean water flow path (<NUM>), and which may include a plurality of filters;
a drain port (<NUM>);
a drain flow path (<NUM>) branched off from the clean water flow path (<NUM>), and having one end connected between the filter device and the water discharge nozzle (<NUM>) and an other end connected to the drain port (<NUM>) to drain water in the clean water flow path (<NUM>) to the outside;
a drain valve (<NUM>) configured to open or close the drain flow path (<NUM>);
a controller (<NUM>) configured to determine a remaining life of the filter device (<NUM>) based on a point in time at which the filter has been replaced, and control the drain valve (<NUM>) to perform a cleaning operation based on the external environment information received through the communication device (<NUM>) or based on the determined remaining life of the filter device.