Patent Description:
Recently, a laundry treating apparatus that performs a drying cycle capable of removing moisture from laundry has appeared. A conventional laundry treating apparatus was able to not only greatly shorten a drying time of the laundry, but also perform sterilization and disinfection of the laundry by supplying hot air to a drum for accommodating therein the laundry to dry the laundry.

In one example, the laundry treating apparatus for performing the drying cycle also includes a conventional laundry treating apparatus for supplying steam to the laundry in order to remove wrinkles of the laundry, improve a drying efficiency, or perform the sterilization or the like.

<CIT>), which is a prior patent document, discloses a condensing dryer equipped with a heat pump system.

Such a condensing dryer has a problem of contamination caused by condensate. Specifically, foreign substances including lint generated from an object-to-be-dried may adhere to the drum, or the contamination may occur from bacteria present in a heat exchange assembly or the like due to prolonged use of the dryer.

The drum may be washed directly in order to solve such problem, but the washing of the drum disposed inside is inconvenient for a user because of a structure of the dryer.

<CIT>) relates to a control method for drying bedclothes in a laundry treatment apparatus including a steam generator.

<CIT>) relates to a laundry machine which has a steam applying facility for the treatment of the laundry with steam.

<CIT>) relates to an apparatus and a method for eliminating wrinkles in clothes by generating steam to the inside of a washing or a drying machine.

The present invention was created to resolve the problems of the conventional laundry dryer and method for controlling the laundry dryer as described above, and is to provide a configuration that may automatically wash a drum.

The present invention is specified by the independent claims.

As described above, according to the laundry dryer and the method for controlling the laundry dryer of the present disclosure, the temperature of the drum is controlled to become the temperature equal to or higher than the reference temperature at which the sterilization is performed, thereby sterilizing the drum.

In addition, the surface temperature of the drum is raised to the temperature equal to or higher than the reference temperature at which the sterilization is performed via the driving control of the compressor, so that the drum may be simply sterilized without a separate component/device for the sterilization.

Hereinafter, a preferred embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.

The present disclosure may be modified variously and may have several embodiments. Therefore, specific embodiments are to be illustrated in the drawings and are to be specifically described in the detailed description. This is not intended to limit the present disclosure to any particular embodiment, and it should be construed to include all changes, or substitutes included in the scope of the present disclosure.

In describing the present disclosure, terms such as first and second may be used to describe various components, but the components may not be limited by the terms. The above terms are only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present disclosure, a first component may be referred to as a second component, and similarly, the second component may also be referred to as the first component.

A term "and/or" may include a combination of a plurality of related listed items or any of the plurality of related listed items.

When a component is referred to as being "connected to" or "in connection with" another component, the component may be directly connected to or in connection with to said another component, but it may be understood that still another component may exist therebetween. On the other hand, when it is mentioned that a component is "directly connected to" or "directly in connection with" another component, it may be understood that there is no still another component therebetween.

The terms used herein are only used to describe a specific embodiment, and are not intended to limit the present disclosure. A singular expression may include a plural expression unless the context clearly dictates otherwise.

Herein, terms such as "comprise" or "include" are intended to specify that a feature, a number, a step, an operation, a component, a part, or combinations thereof described herein exists. It may be understood that an existence or an addition of one or more other features or numbers, steps, actions, components, parts, or combinations thereof is not precluded in advance.

Unless defined otherwise, all terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by one of ordinary skill in the technical field to which the present disclosure belongs. Terms such as those defined in a commonly used dictionary may be interpreted as having meanings consistent with meanings in the context of the related art, and may not be construed in an ideal or overly formal sense unless explicitly defined herein.

In addition, a following embodiment is provided to those with average knowledge in the art for more complete description. Shapes, sizes, and the like of elements in the drawings may be exaggerated for clearer description.

<FIG> discloses a view for illustrating an outer appearance of a laundry dryer according to an embodiment of the present disclosure, <FIG> discloses a cross-sectional view for illustrating an internal structure of a laundry dryer according to an embodiment of the present disclosure.

As shown in <FIG> and <FIG>, a cabinet <NUM> forming an outer body of a laundry dryer <NUM> includes a front panel <NUM> constituting a front surface of the laundry dryer <NUM>, a rear panel <NUM> constituting a rear surface of the laundry dryer <NUM>, a pair of side panels <NUM> constituting side surfaces of the laundry dryer <NUM>, and a top panel <NUM> constituting a top surface of the laundry dryer <NUM>.

The front panel <NUM> may include an inlet <NUM> defined therein to be in communication with a drum <NUM> to be described later, and a door <NUM> pivotably coupled to the cabinet <NUM> to open and close the inlet <NUM>.

A control panel <NUM> is disposed on the front panel <NUM>.

On the control panel <NUM>, input device <NUM> for receiving a control command from a user, output device <NUM> for outputting information such as the control command or the like selectable by the user, and a main controller (not shown) that controls a command to perform a cycle of the laundry dryer <NUM> may be installed.

In one example, the input device <NUM> may include power supply requesting device for requesting power supply to the laundry dryer, course input device for allowing the user to select a desired course among multiple courses, execution requesting device for requesting start of the course selected by the user, and the like.

The output device <NUM> may include at least one of a display panel capable of outputting characters and/or figures, and a speaker capable of outputting audio signals and sounds. The user may easily identify a current situation of the ongoing cycle, a remaining time, and the like via the information output via the output device <NUM>.

Inside the cabinet <NUM>, there are the drum <NUM> rotatably disposed and providing therein a space in which laundry (an object-to-be-dried) is accommodated, a duct assembly <NUM> for forming a flow path for re-supplying air discharged from the drum <NUM> to the drum <NUM>, and a heat exchange assembly <NUM> for dehumidifying and heating air introduced into the duct assembly <NUM> and then re-supplying the air to the drum <NUM>.

The drum <NUM> includes a cylindrical drum body <NUM> with an open front surface. Inside the cabinet <NUM>, a first support <NUM> for rotatably supporting the front surface of the drum body <NUM>, and a second support <NUM> for rotatably supporting a rear surface of the drum body <NUM> may be disposed.

The first support <NUM> may include a first fixed body 22a fixed inside the cabinet <NUM>, a drum inlet 22b defined to extend through the first fixed body 22a to allow the inlet <NUM> and an interior of the drum body <NUM> to communicate with each other, and a first support body 22c disposed on the first fixed body 22a and inserted into the front surface of the drum body <NUM>.

The first support <NUM> may further include a connecting body 22d for connecting the inlet <NUM> and the drum inlet 22b to each other. As shown, the connecting body 22d may be formed in a pipe shape extending from the drum inlet 22b toward the inlet <NUM>. In addition, the connecting body 22d may have an air outlet 22e in communication with the duct assembly <NUM>.

As shown in <FIG>, the air outlet 22e as a passage that allows internal air of the drum body <NUM> to flow to the duct assembly <NUM> may be defined as a through-hole defined to extend through the connecting body 22d.

The second support <NUM> includes a second fixed body 23a fixed inside the cabinet <NUM>, and a second support body 23b disposed on the second fixed body 23a and inserted into the rear surface of the drum body <NUM>.

The second support <NUM> has an air inlet 23c defined to extend through the second fixed body 23a so as to allow the interior of the drum body <NUM> to be in communication with the interior of the cabinet <NUM>.

In this case, the duct assembly <NUM> is constructed to connect the air outlet 22e and the air inlet 23c to each other.

The cylindrical drum body <NUM> may be rotated via a driver <NUM> of various shapes.

Illustratively, in <FIG>, an embodiment in which the driver <NUM> includes a drum motor <NUM> fixed inside the cabinet <NUM>, a pulley <NUM> rotated by the drum motor <NUM>, and a belt <NUM> for connecting a circumferential surface of the pulley <NUM> and a circumferential surface of the drum body <NUM> to each other is shown.

In this case, the first support <NUM> may have a first roller R1 for rotatably supporting the circumferential surface of the drum body <NUM>, and the second support <NUM> may have a second roller R2 for rotatably supporting the circumferential surface of the drum body <NUM>.

However, the present disclosure is not limited thereto. A direct drive-type driver that rotates the drum as the drum motor <NUM> is directly connected to the drum without via the pulley and the belt is also applicable. This naturally falls within the scope of the present disclosure. For convenience, a description will be made based on the illustrated embodiment of the driver <NUM>.

The duct assembly <NUM> includes an exhaust duct <NUM> connected to the air outlet 22e, a supply duct <NUM> connected to the air inlet 23c, and a connecting duct <NUM> that connects the exhaust duct <NUM> and the supply duct <NUM> to each other and has the heat exchange assembly <NUM> installed therein.

The heat exchange assembly <NUM> may be formed as various apparatuses capable of sequentially dehumidifying and heating air introduced into the duct assembly <NUM>. For example, the heat exchange assembly <NUM> may be formed as a heat pump system.

As the heat pump system, the heat exchange assembly <NUM> may include a circulation fan <NUM> for moving air along the duct assembly <NUM>, a first heat exchanger (a heat absorber <NUM>) that performs a dehumidifying function by lowering humidity of air introduced into the duct assembly <NUM>, and a second heat exchanger (a heater <NUM>) that is disposed inside the duct assembly <NUM> and heats air that has passed through the first heat exchanger <NUM>.

The circulation fan <NUM> is constructed to include an impeller 43a disposed in the duct assembly <NUM>, and an impeller motor 43b for rotating the impeller 43a, and provides a flow force to the air moving along the duct assembly <NUM>.

The impeller 43a may be installed at any position among the exhaust duct <NUM>, the connecting duct <NUM>, and the supply duct <NUM>. <FIG> shows an embodiment in which the impeller 43a is disposed in the connecting duct <NUM>. The present disclosure is not limited thereto, but for convenience, a description will be made below based on the embodiment in which the impeller 43a is disposed in the connecting duct <NUM>.

The heat exchange assembly <NUM> exchanges heat with air circulated along the duct assembly <NUM>.

The heat absorber <NUM> and the heater <NUM> are sequentially arranged inside the connecting duct <NUM> along a direction from the exhaust duct <NUM> to the supply duct <NUM>, and are connected to each other via a refrigerant pipe <NUM> for forming a circulation flow path of a refrigerant.

The heat absorber <NUM> is a device for cooling air and evaporating the refrigerant by transferring a heat of air introduced into the exhaust duct <NUM> to the refrigerant.

The heater <NUM> is a device for heating air and condensing the refrigerant by transferring a heat of the refrigerant that has passed through a compressor <NUM> to air.

The compressor <NUM> compresses the refrigerant that exchanges the heat with air circulated along the duct assembly <NUM> by receiving a rotational force by the compressor motor 45a.

In this case, moisture contained in air moves along a surface of the heat absorber <NUM> when passing through the heat absorber <NUM> and is collected on a bottom surface of the connecting duct <NUM>.

As described above, as a configuration related to the heat exchange assembly <NUM> of the heat pump system type including the heat absorber <NUM> and the heater <NUM>, a configuration already known in the art is applicable, and a description of a detailed configuration related thereto will be omitted.

In one example, in order to collect condensate that is condensed from air passing through the heat absorber <NUM> and collected on the bottom surface of the connecting duct <NUM>, the laundry dryer <NUM> according to the present disclosure has a water collecting portion <NUM>.

The condensate condensed in the heat absorber <NUM> may be primarily collected in the water collecting portion <NUM>, and then may be secondary collected in a water storage <NUM>. The water collecting portion <NUM> may be located inside the connecting duct <NUM> as shown, or may be formed separately in a space spaced apart from the connecting duct <NUM>.

The condensate primarily collected via the water collecting portion <NUM> is supplied to the water storage <NUM> via a condensate supply pipe <NUM>. In this regard, the condensate supply pipe <NUM> has a drain pump <NUM> for smooth discharge of the condensate.

The water storage <NUM> includes a water storage tank <NUM> that is constructed to be extended from one side of the front panel <NUM> to the outside. The water storage tank <NUM> collects the condensate delivered from the water collecting portion <NUM> to be described later.

The user may extend the water storage tank <NUM> from the cabinet <NUM> to remove the condensate and then re-install the water storage tank <NUM> in the cabinet <NUM>. Accordingly, the laundry dryer according to the present disclosure may be disposed at any place where a sewer or the like is not installed.

More specifically, the water storage <NUM> may include the water storage tank <NUM> that is detachably disposed in the cabinet <NUM> to provide a space for storing water, and an inlet 72a defined to extend through the water storage tank <NUM> to introduce water discharged from the condensate supply pipe <NUM> into the water storage tank <NUM>.

The water storage tank <NUM> may be formed as a tank in a form of a drawer extendable from the cabinet <NUM>. In this case, the front panel <NUM> of the cabinet has a water storage mounting hole defined therein into which the water storage tank <NUM> is inserted.

A panel <NUM> is fixed to the front surface of the water storage tank <NUM>. The panel <NUM> may be detachably coupled to the water storage mounting hole to form a portion of the front panel <NUM>.

The panel <NUM> may further include a groove 71a into which a user's hand is inserted to grip the panel <NUM>. In this case, the panel <NUM> also functions as a handle for extending the water storage tank <NUM> from the cabinet or retracting the water storage tank <NUM> into the cabinet.

The inlet 72a is defined to receive the condensate discharged from a condensate nozzle <NUM> fixed to the cabinet <NUM>. The condensate nozzle <NUM> may be fixed to the top panel <NUM> of the cabinet <NUM> so as to be located above the inlet 72a when the water storage tank <NUM> is inserted into the cabinet <NUM>.

The user may drain water inside the water storage tank <NUM> by extending the water storage tank <NUM> from the cabinet <NUM> and then turning or tilting the water storage tank <NUM> in a direction in which the inlet 72a is located. A communication hole 72b defined to extend through a top surface of the water storage tank <NUM> may be further included such that water inside the water storage tank <NUM> is easily discharged via the inlet 72a.

In addition, the laundry dryer <NUM> according to the present disclosure has first filtration device F1 and second filtration device F2 as device for removing foreign substances such as lint and dust generated in a drying process of an object to be washed such as the laundry.

The first filtration device F1 is disposed in the exhaust duct <NUM> to primarily filter foreign substances contained in air discharged from the drum <NUM>.

The second filtration device F2 is disposed downstream of the first filtration device F1 in a flow direction of air so as to secondarily filter foreign substances contained in air that has passed through the first filtration device F1. In more detail, as shown, the second filtration device F2 is preferably disposed upstream of the first heat exchanger <NUM> inside the connecting duct <NUM>. This is to prevent the foreign substances contained in air from accumulating in the first heat exchanger <NUM> acting as the heat absorber and contaminating the first heat exchanger <NUM> or causing performance degradation of the first heat exchanger <NUM>.

As for detailed configurations of the first filtration device F1 and the second filtration device F2, any devices known in the art may be applied, so that a description of the detailed configurations thereof will be omitted.

In one example, the laundry dryer <NUM> according to the present disclosure further includes a water supply <NUM> including an internal water supply <NUM> and an external water supply <NUM>, and steam device <NUM> for receiving water from the water supply <NUM> and generating steam.

The steam device <NUM> may generate steam by receiving fresh water, not the condensate. The steam device <NUM> may generate steam by heating water, using an ultrasonic wave, or vaporizing water.

The steam device <NUM> may be controlled to supply steam into the drum body <NUM> by receiving water via the external water supply <NUM> as well as the internal water supply <NUM> as needed.

The external water supply <NUM> may include a direct water valve 82a adjacent to the rear panel <NUM> or fixed to the rear panel <NUM>, and a direct water pipe 82b for supplying water transferred from the direct water valve 82a to the steam device <NUM>.

The direct water valve 82a may be coupled to an external water supply source. For example, the direct water valve 82a may be coupled to a water supply pipe (not shown) extending to the rear surface of the cabinet. Accordingly, the steam device <NUM> may receive water directly via the direct water valve 82a.

Therefore, even when the internal water supply <NUM> is omitted or no water is stored in the internal water supply <NUM>, the steam device <NUM> may receive water for the steam generation via the direct water valve 82a, when necessary.

The direct water valve 82a may be directly controlled by a controller <NUM>.

The controller <NUM> may be installed on the control panel <NUM>, but may be formed as a separate control panel as shown in <FIG> so as to prevent overload of the control panel <NUM> and so as not to increase a manufacturing cost.

In this regard, the controller <NUM> may be disposed adjacent to the steam device <NUM>. The controller <NUM> may be disposed on the side panel <NUM> on which the steam device <NUM> is installed so as to reduce a length of a control line or the like connected to the steam device <NUM>.

In one example, the steam device <NUM> is preferably installed adjacent to the direct water valve 82a. Accordingly, residual water may be prevented from unnecessarily remaining in the direct water pipe 82b, and water may be supplied immediately when necessary.

The controller <NUM> is configured to control an operation of the laundry dryer <NUM> based on an input of the user applied via the input device <NUM>. The controller <NUM> may be composed of a printed circuit board and elements mounted on the printed circuit board. When the user inputs the control command such as selecting a laundry treatment course, operating the laundry dryer <NUM>, or the like via the input device <NUM>, the controller <NUM> may control the operation of the laundry dryer <NUM> based on a preset algorithm.

Specific control content of the controller <NUM> in the present disclosure will be described later.

In one example, <FIG> is a block diagram for illustrating a control configuration in a laundry dryer according to an embodiment of the present disclosure.

Referring to <FIG>, the laundry dryer <NUM> according to an embodiment of the present disclosure may include at least one of the input device <NUM>, the output device <NUM>, communication device <NUM>, sensing device <NUM>, motors <NUM>, 43b, and 45a, a drain pump <NUM>, the steam device <NUM>, and the controller <NUM>.

The input device <NUM> may receive a control command related to the operation of the laundry dryer <NUM> from the user. The input device <NUM> may be composed of a plurality of buttons or may be composed of a touch screen.

Specifically, the input device <NUM> may be formed in a shape to receive selection of a driving course of the laundry treating apparatus or receive a control input related to execution of the selected driving course.

The output device <NUM> may output information related to the operation of the laundry dryer <NUM>. The output device <NUM> may include at least one display.

The information output by the output device <NUM> may include information related to an operating state of the laundry dryer <NUM>. That is, the output device <NUM> may output information related to at least one of the selected driving course, whether a failure has occurred, a driving completion time, and an amount of laundry accommodated in the drum <NUM>.

As an example, the output device <NUM> may be a touch screen integrally formed with the input device <NUM>.

The communication device <NUM> may be in communication with an external network. The communication device <NUM> may receive the control command related to the operation of the laundry treating apparatus from the external network. For example, the communication device <NUM> may receive an operation control command of the laundry dryer transmitted from an external terminal via the external network. This allows the user to remotely control the laundry dryer.

In addition, the communication device <NUM> may transmit information related to an operation result of the laundry treating apparatus to a predetermined server via the external network.

In addition, the communication device <NUM> may be in communication with another electronic device in order to establish an Internet of Things (IOT) environment.

The sensing device <NUM> may sense the information related to the operation of the laundry dryer.

Specifically, the sensing device <NUM> may include at least one of a current sensor, a voltage sensor, a vibration sensor, a noise sensor, an ultrasonic sensor, a pressure sensor, an infrared sensor, a visual sensor (a camera sensor), an electrode sensor, and a temperature sensor.

For example, the current sensor of the sensing device <NUM> may sense a current flowing at a point of a control circuit of the laundry dryer <NUM>.

As another example, the temperature sensor of the sensing device <NUM> may sense a temperature in the duct assembly <NUM> and may sense a temperature in the drum <NUM> according to an embodiment.

As another example, the electrode sensor of the sensing device <NUM> may sense moisture inside the drum <NUM>.

The sensing device <NUM> may include one or more temperature sensors that sense a temperature of the heat exchange assembly <NUM> and transmit the sensed result to the controller <NUM>.

As an example, the sensing device <NUM> may include the one or more temperature sensors to sense one or more of temperatures of air and the refrigerant respectively circulating in the first heat exchanger <NUM> and the second heat exchanger <NUM>.

As another example, the sensing device <NUM> may include the one or more temperature sensors to sense a temperature of the refrigerant circulating in the compressor <NUM>.

The sensing device <NUM> may further include a plurality of temperature sensors for sensing a temperature of air flowing into or out of the drum <NUM>.

As such, the sensing device <NUM> including the plurality of temperature sensors may be formed in a shape in which a sensing module for sensing the temperature is disposed in the heat exchange assembly <NUM> and a sensing module for receiving the sensed result of the plurality of temperature sensors and sensing the temperature is disposed in the controller <NUM>.

As described above, the sensing device <NUM> may include at least one of the various types of sensors, and the types of sensors equipped in the laundry dryer <NUM> are not limited. In addition, the number or installation locations of respective sensors may be designed in various ways depending on a purpose.

The motors <NUM>, 43b, and 45a may include a drum motor <NUM>, an impeller motor 43b, and a compressor motor 45a, and may vary at least one of power, current, voltage, and speed in response to a control command (a command) of the controller <NUM>.

For example, the drum motor <NUM> may vary a rotation speed (rpm) of the drum <NUM> in response to the control command of the controller <NUM>.

As another example, the impeller motor 43b may vary a rotation speed (rpm) of the circulation fan <NUM> in response to the control command of the controller <NUM>.

As another example, the compressor motor 45a may vary a frequency (Hz) of the compressor <NUM> in response to the control command of the controller <NUM>.

In one example, in the present disclosure, in order to drain the condensate condensed during the washing and sterilization process,.

the drain pump <NUM> serves to transfer the condensate collected in the water collecting portion <NUM> to the water storage <NUM>. That is, the drain pump <NUM> may provide the flow force to the condensate collected in the cabinet.

The controller <NUM> may control a driving speed (rpm) of the drain pump <NUM> to drain the condensate stored after being used for the washing and the sterilization.

The steam device <NUM> may include a steam generator <NUM> for generating steam by heating received water, a steam pipe <NUM> through which the generated steam flows, and a steam nozzle <NUM> for spraying steam into the drum body <NUM>.

As an example, the steam generator <NUM> is expressed to use a scheme (hereinafter, referred to as a 'whole heating scheme' for convenience) of generating steam by heating a certain amount of water contained therein with a heater (not shown in the drawing), but is not limited thereto.

The controller <NUM> may control the component included in the laundry dryer <NUM>.

First, the controller <NUM> may generate at least one of a power command value, a current command value, a voltage command value, and a speed command value in order to control rotation of the drum motor <NUM>, the impeller motor <NUM>, and the compressor motor 45a.

In this regard, in the present disclosure, the controller <NUM> may control the drum motor <NUM>, the impeller motor 43b, and the compressor motor 45a, independently.

Accordingly, the controller <NUM> may control an operation of at least one of the drum <NUM>, the circulation fan <NUM>, and the heat exchange assembly <NUM> based on the control input input to the input device <NUM>.

That is, the controller <NUM> may control the rotation speed and a rotation pattern of the drum <NUM> based on the control input of the user input to the input device <NUM>. In addition, the controller <NUM> may control the rotation speed or an operation time point of the circulation fan <NUM> based on the control input of the user input to the input device <NUM>.

In addition, the controller <NUM> may control the heat exchange assembly <NUM> to adjust the temperature inside the drum <NUM> based on the control input of the user input to the input device <NUM>.

For example, the controller <NUM> may control the driving frequency (Hz) of the compressor <NUM> based on the control input of the user input to the input device <NUM>.

In addition, the controller <NUM> may generate at least one of the power command value, the current command value, and the voltage command value to control the operation of the steam generator <NUM>.

That is, the controller <NUM> may control a heating time of the steam generator <NUM> based on the control input of the user input to the input device <NUM>.

In this regard, the controller <NUM> may adjust the heating time of the steam generator <NUM> using information such as external temperature, the laundry amount, or the like.

In one example, in a case of a conventional laundry dryer, the drum and the circulation fan are connected to one motor. Therefore, the drum and the circulation fan rotated at the same time and stopped rotating at the same time.

In this regard, when spraying steam to the laundry dryer, it was necessary to stop the rotation of the circulation fan in order to sufficiently supply the sprayed steam to the object-to-be-dried, and the drum was also stopped to stop the circulation fan.

However, when the drum stops rotating, the object-to-be-dried is not able to be inverted. In addition, even when steam is supplied to the object-to-be-dried, steam is supplied only to objects-to-be-dried located in a direction in which steam is sprayed. Therefore, there was a limit in supplying steam evenly to entire objects-to-be-dried.

In order to solve such problem, in the laundry dryer <NUM> according to an embodiment of the present disclosure, the drum motor <NUM> and the impeller motor 43b are formed separately from each other. In addition, the controller <NUM> may control the drum motor <NUM>, the impeller motor 43b, and the compressor motor 45a, independently.

Therefore, the controller <NUM> according to an embodiment of the present disclosure may stop the rotation of the circulation fan <NUM> while maintaining the rotation of the drum <NUM> when steam is sprayed from the steam device <NUM>.

In addition, the controller <NUM> of the present disclosure may stop the operation of the compressor <NUM> when operating the steam device <NUM> in order to prevent the power supply from being cut off due to an instantaneous and sudden increase in power consumption of the entire laundry dryer <NUM>.

Specifically, when operating the steam generator <NUM> to preheat water or generate steam, the controller <NUM> may stop the rotation of the compressor motor 45a.

In the present invention, the controller <NUM> increases the temperature inside the cabinet <NUM> so as to sterilize and dry the interior of the drum <NUM> and the duct assembly <NUM> and then operate the steam device <NUM> to supply steam into the drum <NUM> so as to sterilize the interior of the drum <NUM> and the duct assembly <NUM>.

While sterilizing and drying the interior of the drum <NUM> and the duct assembly <NUM>, the controller <NUM> may operate the compressor <NUM> to raise the temperature inside the cabinet <NUM>.

In this regard, the controller <NUM> may rotate (operate) the drum <NUM> and the circulation fan <NUM> while the compressor <NUM> is operating.

In one example, after stopping the operation of the compressor <NUM>, the controller <NUM> may operate the steam device <NUM> so as to supply steam to the drum <NUM>, thereby sterilizing the interior of the drum <NUM> and the duct assembly <NUM>.

While operating the steam device <NUM>, the controller <NUM> may rotate the drum <NUM> in order to evenly supply steam into the drum <NUM>, and stop the rotation of the circulation fan <NUM> to sufficiently supply steam to the drum <NUM>.

In one example, the controller <NUM> may supply a preset amount of water to the steam device <NUM> and operate the steam device <NUM> to heat the stored water when power is applied, thereby generating steam for a preset steam spray time ts.

In this regard, the controller <NUM> may spray steam from the steam device <NUM> after the operation of the circulation fan <NUM> is stopped.

In addition, after stopping the operation of the steam device <NUM>, the controller <NUM> may operate the circulation fan <NUM> again.

In one example, the controller <NUM> may drain the condensate by operating the drain pump <NUM> for a preset drain time after stopping the operation of the steam device <NUM>.

In one example, control of the controller <NUM> over time will be described later with reference to <FIG> and <FIG>.

<FIG> discloses a flowchart showing a sequence of a method for controlling the laundry dryer <NUM> according to an embodiment of the present disclosure, and (a) and (b) in <FIG> respectively disclose illustrative views according to a specific application example of a steam drying method related to an embodiment of the present disclosure.

Referring to <FIG>, the method for controlling the laundry dryer <NUM> according to an embodiment of the present disclosure is as follows.

The method for controlling the laundry dryer <NUM> according to an embodiment of the present disclosure may include a course input step (S10), a sterilization drying step (S20), a steam washing step (S30) and a blowing step (S40).

In the course input step (S10), a control input for performing a whole sterilization course for sterilizing the drum <NUM>, a filter F including the first filtration device F1 and the second filtration device F2, and the heat exchange assembly <NUM> is input.

That is, when the laundry dryer <NUM> of the present disclosure is turned on, the user may input the control input to the input device <NUM>. In this regard, the user may input the whole sterilization course to remove microorganisms that may exist in the drum <NUM>, the filter F, and the heat exchange assembly <NUM> by long-term use of the laundry dryer <NUM>.

In this regard, the microorganisms may include Staphylococcus, Pseudomonas aeruginosa, Escherichia coli, and house dust mites.

In one example, in the whole sterilization course, it is preferable that the sterilization operation for the drum <NUM>, the filter F, and the heat exchange assembly <NUM> is performed in a state in which a drying target (hereinafter, referred to as the object-to-be-dried) including clothes, towels, and the like is not accommodated in the drum <NUM>.

That is, in the method for controlling the laundry dryer <NUM> according to the present invention, the sterilization operation for the drum <NUM>, the filter F, and the heat exchange assembly <NUM> is performed in a no load condition.

The sterilization drying step (S20) increases the temperature inside the cabinet <NUM> for the sterilization.

Specifically, the sterilization drying step (S20) may heat the interior of the cabinet <NUM> for a preset drying time td.

For example, the sterilization drying step (S20) may heat the interior of the cabinet <NUM> for a duration of <NUM> minutes or longer and <NUM> minutes or shorter.

In the sterilization drying step (S20), the controller <NUM> may rotate the drum motor <NUM> at a reference speed Wr input in advance (S21). For example, the controller <NUM> may continuously rotate the drum motor <NUM> while maintaining the rotation speed of the drum motor <NUM> at a speed equal to or greater than <NUM> rpm and equal to or smaller than <NUM> rpm, thereby continuously rotating the drum <NUM> at a constant speed.

This is to evenly heat the interior of the drum <NUM> by supplying hot air thereto while rotating the drum <NUM> at the constant speed.

In the sterilization drying step (S20), the controller <NUM> may drive (rotate) the compressor <NUM> in order to raise the internal temperature of the drum <NUM> (S32).

In this regard, the controller <NUM> may drive the compressor <NUM> by adjusting an operating frequency f of the compressor <NUM> to be within a range of a sterilization frequency fs.

As an example, the controller <NUM> may drive the compressor <NUM> at the operating frequency f that is a sterilization frequency fs equal to or higher than <NUM>.

When activating the sterilization drying step (S20), the controller <NUM> may drive the compressor <NUM> at the operating frequency f that is the sterilization frequency fs in order to rapidly increase the internal temperature of the drum <NUM>.

In this regard, the controller <NUM> may give a control command to increase an output for driving the compressor <NUM> to the sterilization frequency fs at once, but it is preferable to give a control command to increase the rotation speed of the compressor motor 45a over several steps in order to prevent malfunction caused by overload of the compressor motor 45a.

As an example, the controller <NUM> may primarily generate a control command for driving the compressor <NUM> at a frequency equal to or higher than <NUM> and equal to or lower than <NUM>, secondarily generate a control command for driving the compressor <NUM> at a frequency equal to or higher than <NUM> and equal to or lower than <NUM>, and finally generate a control command for driving the compressor <NUM> at the sterilization frequency fs.

Therefore, the refrigerant of the heat exchange assembly <NUM> may be compressed at a high temperature and with a high pressure by the driving of the compressor <NUM>, and may exchange the heat with air in the duct assembly <NUM>. As a result, the temperature of air in the duct assembly <NUM> may be increased.

In one example, in the present disclosure, in order to prevent a malfunction or blockage of the power supply caused by an excessive increase in the power consumption of the compressor <NUM>, the controller <NUM> may measure a refrigerant discharge temperature of the compressor <NUM> or the temperature of the compressor, and reduce the operating frequency of the compressor <NUM> when a preset reference temperature is reached.

For example, the controller <NUM> may measure a top surface temperature of the compressor <NUM>, lower the operating frequency f of the compressor <NUM> to a frequency equal to or higher than <NUM> and equal to or lower than <NUM> when the measured temperature of the compressor <NUM> reaches <NUM> degrees Celsius, and drive the compressor <NUM> at the sterilization frequency fs again when the temperature of the compressor <NUM> is lowered.

In the sterilization drying step (S20), the controller <NUM> may operate the circulation fan <NUM> to circulate air during the heating (S23).

Specifically, in the sterilization drying step (S20), the controller <NUM> may drive the circulation fan <NUM> at a preset circulation speed V while the compressor <NUM> is driven.

For example, in the sterilization drying step (S20), the controller <NUM> may drive (rotate) the circulation fan <NUM> at a speed equal to or higher than <NUM> rpm and equal to or lower than <NUM> rpm while the compressor <NUM> is driven.

Accordingly, air heated by the driving of the compressor <NUM> may be circulated while flowing through the drum <NUM> and the duct assembly <NUM> by the rotation of the circulation fan <NUM>.

As a result, a temperature T inside the cabinet <NUM> may increase to a temperature equal to or higher than a sterilization temperature Ts for sterilizing the microorganisms or the like present in the drum <NUM> and the duct assembly <NUM> by the driving of the compressor <NUM> and the circulation fan <NUM> (T≥ Ts).

For example, in the sterilization drying step (S20), the internal temperature of the cabinet <NUM> may be increased until a temperature of a heat exchanger (which may refer to an evaporator <NUM>) in a direction in which air is introduced from the drum <NUM> becomes a temperature equal to or higher than <NUM> degrees Celsius.

In the sterilization drying step (S20), the controller <NUM> may supply water from the water supply <NUM> to the steam device <NUM> (S24).

In this regard, controller <NUM> may determine whether to supply water by measuring a water level inside the steam generator <NUM>.

That is, the controller <NUM> does not supply water to the steam generator <NUM> when the amount of water stored in the steam generator <NUM> is equal to or greater than an amount to be sprayed in the steam washing step (S30) to be described later, but supplies water from the water supply <NUM> to the steam generator <NUM> when the amount of water stored in the steam generator <NUM> is smaller than the amount of water to be sprayed in the steam washing step (S30) to be described later.

When it is necessary to supply water to the steam generator <NUM>, the controller <NUM> may operate a water supply pump disposed in the internal water supply <NUM> according to an embodiment so as to supply water into the steam generator <NUM>, and may open the direct water valve 82a disposed in the external water supply <NUM> so as to supply water into the steam generator <NUM>.

For example, the controller <NUM> may supply water of an amount equal to or greater than <NUM> cc from the water supply <NUM> to the steam generator <NUM>, and a time required to supply water of the water supply <NUM> to the steam generator <NUM> may be <NUM> seconds or longer and <NUM> seconds or shorter.

As another example for supplying sufficient water, the controller <NUM> may supply water of an amount equal to or greater than <NUM> cc and equal to or smaller than <NUM> cc from the water supply <NUM> to the steam generator <NUM>, and a time required to supply water of the water supply <NUM> to the steam generator <NUM> may be <NUM> seconds or longer and <NUM> minute <NUM> seconds or shorter.

Therefore, in the sterilization drying step (S20), the controller <NUM> operates the drum <NUM>, the compressor <NUM>, and the circulation fan <NUM> to increase the temperature inside the cabinet <NUM> including the drum <NUM> and the duct assembly <NUM> and increase the temperatures of the drum <NUM>, the filter F, and the heat exchange assembly <NUM> to a temperature equal to or higher than the sterilization temperature Ts.

The steam washing step (S30) supplies steam into the drum <NUM> for the sterilization inside the drum <NUM> and the duct assembly <NUM> after the sterilization drying step (S20).

In the steam washing step (S30), the controller <NUM> may continuously rotate the drum motor <NUM> at the reference speed Wr input in advance (S31). For example, the controller <NUM> may continuously rotate the drum motor <NUM> while maintaining the rotation speed of the drum motor <NUM> at a speed equal to or higher than <NUM> rpm and equal to or lower than <NUM> rpm, thereby continuously rotating the drum <NUM> at a constant speed.

Therefore, when steam is sprayed while the drum <NUM> continues to rotate, steam may be evenly supplied into the drum <NUM> and the interior of the drum <NUM> may be sterilized evenly.

In the steam washing step (S30), the controller <NUM> does not drive the compressor <NUM> in order to prevent the instantaneous increase in the power consumption of the laundry dryer <NUM> (S32).

In the steam washing step, the controller <NUM> may stop the operation of the circulation fan <NUM> that was operating in the sterilization drying step (S20) (S33).

Accordingly, the circulation of air circulating inside the drum <NUM> and the duct assembly <NUM> may be stopped, and steam sprayed from the steam device <NUM> may be sufficiently supplied to the drum <NUM>.

In the steam washing step (S30), the controller <NUM> operates the steam device <NUM> to supply steam into the drum <NUM> (S34).

The steam washing step (S30) includes a steam preheating step (S34a) and a steam spraying step (S34b).

In the steam preheating step (S34a), the controller <NUM> may apply power to the steam device <NUM> to heat water supplied for the steam generation for a preset preheating time th.

In detail, in the steam preheating step (S34a), the controller <NUM> may heat water supplied to the steam generator <NUM> by applying power to a heater (not shown in the drawing) disposed in the steam generator <NUM>. In this regard, the controller <NUM> may apply power to the heater during the preheating time th, and the preheating time th may be set to be equal to or longer than a time required for water to reach a boiling point.

For example, in the steam preheating step (S34a), the controller <NUM> may generate a control command to apply power to the steam device <NUM> for <NUM> minutes and <NUM> seconds or longer and <NUM> minutes and <NUM> seconds or shorter.

In the steam spraying step (S34b), the controller <NUM> may spray steam generated from the steam device <NUM> into the drum <NUM> as much as a preset spraying amount after the steam preheating step (S34a).

Specifically, in the steam spraying step (S34b), the controller <NUM> may generate a control command to the steam generator <NUM> such that water heated in the steam generator <NUM> and started to boil flows through the steam pipe <NUM> and is sprayed into the drum body <NUM> via the steam nozzle <NUM>.

For example, in the steam spraying step (S34b), the controller <NUM> may spray water of an amount equal to greater than <NUM> cc and equal to or smaller than <NUM> cc from the steam generator <NUM> into the drum <NUM>. In this regard, a time required for spraying steam may be <NUM> minute <NUM> seconds or longer and <NUM> minutes <NUM> seconds or shorter.

Therefore, in the steam washing step (S30), the controller <NUM> may operate the drum <NUM> and the steam device <NUM> to evenly supply high-temperature steam into the drum <NUM> to remove bacteria and the like.

The blowing step (S40) sterilizes the entire filter F and the entire heat exchange assembly <NUM> arranged in the duct assembly <NUM> at a high temperature by circulating air inside the drum <NUM> after the steam washing step (S30).

For example, the blowing step (S40) may circulate air inside the drum <NUM> and the duct assembly <NUM> for <NUM> minutes or longer and <NUM> minutes or shorter so as to supply heat and enthalpy to the filter F and the heat exchange assembly <NUM>.

In the blowing step (S40), the controller <NUM> may continuously rotate the drum motor <NUM> at the reference speed Wr input in advance (S41). For example, the controller <NUM> may continuously rotate the drum motor <NUM> while maintaining the rotation speed of the drum motor <NUM> at a speed equal to or higher than <NUM> rpm and equal to or lower than <NUM> rpm, thereby continuously rotating the drum <NUM> at the constant speed.

Therefore, air circulating in the drum <NUM> and the duct assembly <NUM> may sterilize the interior of the drum <NUM> evenly.

In the blowing step (S40), the controller <NUM> may not drive the compressor <NUM> in order to improve a power efficiency (S42).

In the blowing step (S40), the controller <NUM> may rotate the circulation fan <NUM> to circulate air that has obtained high heat or high enthalpy in the sterilization drying step (S20) and the steam washing step (S30) (S43).

Specifically, in the blowing step (S40), the controller <NUM> may drive the circulation fan <NUM> at the preset circulation speed V.

For example, in the blowing step (S40), the controller <NUM> may drive (rotate) the circulation fan <NUM> at a speed equal to or higher than <NUM> rpm and equal to or lower than <NUM> rpm while the compressor <NUM> is driven.

In the blowing step (S40), because sufficient moisture has been supplied to the object-to-be-dried, the controller <NUM> may not operate (stop the operation of) the steam device <NUM> (S44).

Therefore, air that has obtained the high heat or the high enthalpy in the sterilization drying step (S20) and the steam washing step (S30) may be circulated while flowing through the drum <NUM> and the duct assembly <NUM> by the rotation of the circulation fan <NUM>.

As a result, according to the blowing step (S40) of the present disclosure, surface temperatures of the drum <NUM>, the filter F, and the heat exchange assembly <NUM> may be increased to a temperature equal to or higher than the sterilization temperature Ts for removing the microorganisms or the like, and may be maintained for the reference time ts for the sterilization or longer.

For example, the blowing step (S40) may maintain the surface temperatures of the drum <NUM>, the filter F, and the heat exchange assembly <NUM> for <NUM> minutes or longer at a temperature equal to or higher than <NUM> degrees Celsius.

In one example, in the blowing step (S40), the controller <NUM> may operate the drain pump <NUM> to discharge the condensate collected in the cabinet <NUM> (S45).

In the blowing step (S40), the controller <NUM> may drain the condensate for a preset drainage time td when activating the blowing step (S40).

That is, the controller <NUM> may operate the drain pump <NUM> to move the condensate collected in the water collecting portion <NUM> to the water storage tank <NUM>.

In this regard, the drainage time td may be <NUM> seconds or longer and <NUM> seconds or shorter.

In one example, <FIG> discloses a view for illustrating a sterilization principle based on a method for controlling a laundry dryer of an embodiment of the present disclosure, <FIG> discloses a graph about a temperature of a filter based on a method for controlling a laundry dryer of an embodiment of the present disclosure, and <FIG> discloses a graph about a temperature of a front end of an evaporator based on a method for controlling a laundry dryer of an embodiment of the present disclosure.

Sterilization effects according to the present disclosure will be described with reference to <FIG> as follows.

First, an effect on each component of the present disclosure is as follows.

According to the method for controlling the laundry dryer <NUM> of an embodiment of the present disclosure, the drum <NUM> of the present disclosure is controlled to rotate while maintaining the constant speed in the sterilization drying step (S20), the steam washing step (S30), and the blowing step (S40) (S21, S31, S41).

That is, the drum <NUM> continues to rotate after the sterilization drying step (S20). Therefore, according to the present invention, hot air and steam for the sterilization may be evenly supplied to an inner surface of the drum <NUM>, and the drum <NUM> may be evenly sterilized.

In one example, the compressor <NUM> of the present disclosure is driven in the sterilization drying step (S20) (S22) so as to heat air inside the drum <NUM> and the duct assembly <NUM> and then the driving of the compressor <NUM> is terminated to reduce the power consumption (S32, S42).

The compressor <NUM> heats air flowing inside the drum <NUM> and the duct assembly <NUM> to provide hot air (heat) supplied into the drum <NUM> and the duct assembly <NUM>. Therefore, surfaces of the drum <NUM>, the filter F, and the heat exchange assembly <NUM> are heated via the driving of the compressor <NUM>, and the surfaces of the drum <NUM>, the filter F, and the heat exchange assembly <NUM> are sterilized by the supply of the high-temperature heat.

In one example, the circulation fan <NUM> of the present disclosure starts to rotate in the sterilization drying step (S20) (S23), stops rotating in the steam washing step (S30) (S33), and rotates again in the blowing step (S40) (S43).

The circulation fan <NUM> of the present disclosure is controlled independently of the rotation of the drum <NUM>, is rotated when the air heated by the driving of the compressor <NUM> is circulated, and stops rotating during the steam spray when the flow of air is unnecessary.

Therefore, because of the circulation fan <NUM> of the present disclosure, a supply efficiency of steam is improved, so that a sterilization efficiency of the drum <NUM> is improved.

The steam device <NUM> of the present disclosure is operated for the preheating and the steam spraying for the steam generation in the steam washing step (S30) (S34).

In the present disclosure, the sterilization effect of the steam spray is as follows.

When hot air is supplied to the drum <NUM> and the duct assembly <NUM> in the sterilization drying step (S20), the temperature inside the drum <NUM> reaches the sterilization temperature (which may be equal to or higher than <NUM> degrees Celsius) required for the sterilization. In this regard, when the steam device <NUM> sprays high-temperature steam to the drum <NUM> in the steam washing step (S30) of the present disclosure, the enthalpy of the air inside the drum <NUM> is increased, and the microorganisms including the bacteria are sterilized by being exposed to the high heat.

That is, according to the steam washing step (S30), as steam with high heat capacity is supplied into the drum <NUM> heated to have the temperature equal to or higher than the sterilization temperature Ts, the microorganisms such as the bacteria are exposed to high enthalpy, and as a result, the microorganisms such as the bacteria die as cell membranes thereof are destroyed (see <FIG>).

Thereafter, by circulating air of the drum <NUM> and the duct assembly <NUM> via the blowing step (S40), the surface temperatures of the drum <NUM>, the filter F, and the heat exchange assembly <NUM> may be maintained at the temperature equal to or higher than the sterilization temperature (<NUM> degrees Celsius) for the reference time (ts: <NUM> minutes) for the sterilization or longer (see <FIG> and <FIG>). Therefore, the microorganisms present on the surfaces of the drum <NUM>, the filter F, and the heat exchange assembly <NUM> may be exposed to energy of high heat, so that cells thereof may be destroyed and the microorganisms and the like will die.

Hereinabove, the present disclosure has been described in detail through a specific embodiment, but this is for specifically illustrating the present disclosure, and the present disclosure is not limited thereto. It is clear that the present disclosure may be modified or improved by a person having ordinary knowledge in the field within the technical scope of the present disclosure.

Claim 1:
A laundry dryer comprising:
a drum (<NUM>) rotatably installed inside a cabinet (<NUM>) for forming an outer appearance of the laundry dryer (<NUM>) and configured to accommodate an object-to-be-dried therein;
a duct assembly (<NUM>) provided to re-supply air discharged from the drum (<NUM>) to the drum (<NUM>);
a circulation fan (<NUM>) configured to provide a flow force to air moving along the duct assembly (<NUM>);
a heat exchange assembly (<NUM>) disposed in the duct assembly (<NUM>) and configured to exchange heat with air circulated along the duct assembly (<NUM>);
a compressor (<NUM>) configured to compress a refrigerant to exchange heat with air circulated along the duct assembly (<NUM>);
steam means (<NUM>) configured to supply steam into the drum (<NUM>); and
a controller (<NUM>) configured to control the drum (<NUM>), the circulation fan (<NUM>), the compressor (<NUM>), and the steam means (<NUM>),
wherein the controller (<NUM>) is configured to drive the compressor (<NUM>) to increase a temperature inside the cabinet (<NUM>) and then increase an amount of heat inside the drum (<NUM>) by operating the steam means (<NUM>) so as to sterilize the inside of the drum (<NUM>),
wherein the controller (<NUM>) is configured to operate the drum (<NUM>) and the circulation fan (<NUM>) while operating the compressor (<NUM>),
characterized in that
the controller (<NUM>) is configured to allow the sterilization operation for the drum (<NUM>) to be performed under a condition of no load on the drum (<NUM>).