Patent Description:
A dryer is an apparatus for drying clothes (hereinafter, referred to as an object to be dried) by spinning a drum that accommodates the object to be dried and supplying hot air into the drum.

The existing dryer is installed and used in a washing room or a utility room separately partitioned off in the house, but the washing room or the utility room has no window and is narrow and small, thereby having bad ventilation. When the washing room or the utility room has high humidity, the dryer installed therein is more likely to be corroded, giving an unpleasant feeling to the user going in and out of the space. An extra dehumidifier may be installed in the space where the dryer is installed, but it is inefficient in terms of costs and spatial use.

In the meantime, heat pump dryers may dry the object to be dried using a refrigerant cycle. The aforementioned problems may be solved all at once by properly utilizing characteristics of the refrigerant cycle, although an essential function of the dryer is to dry the object to be dried. Exemplary embodiments of dryers of the prior art which include a dehumidifying function dehumidifying humid outside air are disclosed in <CIT>.

The invention provides a dryer that uses a function already equipped in the dryer to have better dehumidification efficiency.

According to an aspect of the disclosure, a dryer includes a main body; a drum arranged in the main body for receiving an object to be dried; a driving motor configured to rotate the drum; an input module configured to receive an input of a dry mode or a dehumidification mode from a user; a heat exchanger arranged in the main body; and a controller configured to control the driving motor to rotate the drum at a first rotation speed in response to the dry mode being input, and control the driving motor to rotate the drum at a second rotation speed different from the first rotation speed in response to the dehumidification mode being input.

The controller may control the driving motor to rotate the drum at a second rotation speed lower than the first rotation speed in the dehumidification mode.

The controller may control the driving motor to rotate the drum at a second rotation speed higher than the first rotation speed in the dehumidification mode.

The controller rotates the drum for air brought in from outside to reach an inner surface of the drum in response to receiving a command to select the dehumidification mode through the input module.

The dryer further includes a compressor configured to produce hot air, and the controller controls the compressor for temperature in the drum to be the first temperature in the dry mode, and control the compressor for temperature in the drum to be the second temperature different from the first temperature in the dehumidification mode.

The controller may control the compressor for the temperature in the drum to be a second temperature lower than the first temperature in the dehumidification mode.

The dryer further includes a fan configured to form a flow path through which air flows in from outside and air having passed the heat exchanger and the drum flows out.

The controller generates a control signal to drive the fan in response to receiving a command to select the dehumidification mode through the input module.

According to an aspect of the disclosure, a method of controlling the dryer of the invention includes receiving a command to select a dehumidification mode; controlling a fan to form a flow path to force air brought in from outside to pass a drum and flow out; and controlling a driving motor to rotate the drum at a second rotation speed in the dehumidification mode, wherein the second rotation speed is different from a first rotation speed at which the drum rotates in a dry mode.

The controlling of the driving motor may include controlling the driving motor to rotate the drum at a second rotation speed lower than the first rotation speed in the dehumidification mode.

The controlling of the driving motor may include controlling the driving motor to rotate the drum at a second rotation speed higher than the first rotation speed in the dehumidification mode.

The controlling of the driving motor includes rotating the drum for the air brought in from outside to reach an inner surface of the drum.

The method of controlling the dryer further includes controlling a compressor for temperature in the drum to be a first temperature in the dry mode, and controlling the compressor for the temperature in the drum to be a second temperature different from the first temperature in the dehumidification mode.

The controlling of the compressor may include controlling the compressor for the temperature in the drum to be a second temperature lower than the first temperature in the dehumidification mode.

The controlling of the driving motor includes generating a control signal to drive a fan in response to receiving a command to select the dehumidification mode through an input module.

According to the disclosure, dehumidification efficiency of a dryer may increase by preventing condensation of steam in the dryer by rotating a drum for dehumidification.

Like numerals refer to like elements throughout the specification. Not all elements of embodiments of the disclosure will be described, and description of what are commonly known in the art or what overlap each other in the embodiments will be omitted. The term 'unit, module, member, or block' may refer to what is implemented in software or hardware, and a plurality of units, modules, members, or blocks may be integrated in one component or the unit, module, member, or block may include a plurality of components, depending on the embodiment of the disclosure.

It will be further understood that the term "connect" or its derivatives refer both to direct and indirect connection, and the indirect connection includes a connection over a wireless communication network.

The term "include (or including)" or "comprise (or comprising)" is inclusive or open-ended and does not exclude additional, unrecited elements or method steps, unless otherwise mentioned.

Throughout the specification, when it is said that a member is located "on" another member, it implies not only that the member is located adjacent to the other member but also that a third member exists between the two members.

Reference numerals used for method steps are just used for convenience of explanation, but not to limit an order of the steps. Thus, unless the context clearly dictates otherwise, the written order may be practiced otherwise.

Reference will now be made in detail to embodiments of the disclosure, which are illustrated in the accompanying drawings. A dryer <NUM> according to the disclosure may be used to dry and/or manage clothing, shoes, miscellaneous items, etc..

Referring to <FIG>, a direction along the X-axis may be defined as a front-back direction, a direction along the Y-axis may be defined as a left-right direction, and a direction along the Z-axis may be defined as an up-down direction The terms "front-back direction", "left-right direction", "up-down (vertical) direction", etc., as herein used are defined with respect to the drawings, but the terms may not restrict the shapes and positions of the respective components.

<FIG> is an exterior view of a dryer, according to an embodiment. <FIG> is a side cross-sectional view of a dryer in a dry mode, according to an embodiment, <FIG> is a side cross-sectional view of a dryer in a dehumidification mode, according to an embodiment, <FIG> illustrates rotation of a drum while a dryer is in a dehumidification mode, according to an embodiment, and <FIG> illustrates a base of a dyer, according to an embodiment.

Referring to <FIG>, a dryer <NUM> according to an embodiment of the disclosure may include a main body <NUM>. The main body <NUM> may include a front plate <NUM>, a top plate <NUM>, side plates <NUM>, a rear plate <NUM>, and a bottom plate <NUM>, which may form into an almost rectangular shape. The main body <NUM> may constitute a main frame of the dryer <NUM>.

A returnable bottle <NUM> may be arranged in the main body <NUM>. Specifically, the returnable bottle <NUM> may be arranged in an upper portion on the front plate <NUM> of the main body <NUM>. The returnable bottle <NUM> may store condensate water produced from the operation of a refrigerant cycle, which will be described later.

There may be an input module <NUM> provided on the main body <NUM> to operate the dryer. Specifically, the input module <NUM> may be arranged on an upper portion of the front plate <NUM> of the main body <NUM>. The input module <NUM> may include at least one of a turnable switch 17a, a display 17b, and buttons 17c. The turnable switch 17a may be arranged for the user to select a mode of the dryer <NUM> by grasping and turning the tunable switch 17a. The display 17b may be arranged to display an operation state and/or a user manipulation state of the dryer <NUM>. The display 17b may be provided to enable touch inputs. The buttons 17c may be arranged for the user to select a mode of the dryer <NUM> by pressing the button. It is not, however, limited thereto, and there may be various manipulation methods.

The main body <NUM> may include a base <NUM>. The base <NUM> may be arranged at the bottom of the main body <NUM>, forming the bottom plate <NUM>. There may be legs <NUM> (see <FIG>) at the bottom plate <NUM> to support the main body <NUM>.

The dryer <NUM> may include a drum <NUM> arranged to receive an object to be dried (also referred to simply as an object). The drum <NUM> may include an entrance of the drum, through which to throw in the object. The drum <NUM> may be rotationally arranged in the main body <NUM>.

The dryer <NUM> may include a driver to rotate the drum <NUM>. Referring to <FIG>, the driver may include a driving motor <NUM> settled on the base <NUM>, a pulley <NUM> rotated by the driving motor <NUM>, and a belt (not shown) that connects the pulley <NUM> to the drum <NUM> for transferring power of the driving motor <NUM> to the drum <NUM>.

In the meantime, in an embodiment, the dryer <NUM> may suck in humid outside air while the door <NUM> is open, and dehumidify outdoor space by discharging the air dried by the refrigerant cycle of a heat exchanger <NUM>. In this case, as the door <NUM> of the dryer <NUM> is open, an open flow path may be formed. Furthermore, in an embodiment, the dryer <NUM> may further include a dehumidification unit <NUM> that may form the open flow path even while the door <NUM> is closed.

Referring to <FIG>, the drum <NUM> may include a flow-in port <NUM> through which air flows to the inside <NUM> of the drum, and a flow-out port <NUM> through which air flows out of the drum from the inside <NUM> of the drum. The flow-in port <NUM> may be formed on one side of the drum <NUM> and the flow-out port <NUM> may be formed on the other side of the drum <NUM>. Specifically, the flow-in port <NUM> may be a rear opening of the drum <NUM>, and the flow-out port <NUM> may be a front opening of the drum <NUM>. For example, the front opening of the drum <NUM> may be an entrance of the drum <NUM>.

Hot and dry air may flow into the drum <NUM> through the flow-in port <NUM>, and dry the object contained in the drum <NUM>. Furthermore, the air that has gotten to contain lots of water after the drying of the object may get out of the drum <NUM> through the flow-out port <NUM>.

A plurality of lifters <NUM> may be arranged inside the drum <NUM>. The lifters <NUM> may lift and drop the object so that the object contacts hot air while drifting in the space in the drum <NUM>.

To throw the object into the drum <NUM>, a first opening (or inlet) <NUM> may be formed on the front of the main body <NUM>, and a door <NUM> may be installed to open or close the first opening <NUM>. The door <NUM> may be hinged to one side of the first opening <NUM> to pivot from the one side.

The base <NUM> (see <FIG>) may be arranged at the bottom of the drum <NUM>. Referring to <FIG>, a heat exchanger <NUM>, a compressor <NUM>, an expansion device <NUM>, etc., which constitute the refrigerant cycle, may be settled on the base <NUM>. A fan <NUM>, the driving motor <NUM>, the pulley <NUM>, etc., may also be settled on the base <NUM>. A base cover <NUM> may be arranged above the base <NUM> to cover the heat exchanger <NUM> and so on. For example, the base cover <NUM> and the base <NUM> may form a duct structure.

The fan <NUM> may be arranged on the base <NUM>. The fan <NUM> may form an air flow path by generating wind power. For example, the fan <NUM> may discharge air in a radial direction. For this, the fan <NUM> may include a rotation shaft <NUM> formed at the center, and a plurality of blades <NUM> formed in a circumferential direction centered on the rotation shaft <NUM>.

Referring to <FIG>, in a dry mode, a closed flow path may be formed in the main body <NUM> of the dryer <NUM>. Herein, the closed flow path may be an air movement path (see arrows in <FIG>) arranged for air in the cabinet to circulate through the heat exchanger <NUM> and the drum <NUM>. The closed flow path may not be connected to the outside of the main body <NUM> to prevent the outside air from flowing in or out. That is, a flow of air may form a closed loop.

Referring to <FIG>, a filter unit <NUM> may be detachably installed in the dryer <NUM>. Specifically, the filter unit <NUM> may be detachably installed in the main body <NUM> through a second opening <NUM>. The filter unit <NUM> may be attached to or detached from a unit receiver <NUM>. The filter unit <NUM> may prevent air from leaking out of the closed flow path. In other words, the filter unit <NUM> may prevent declining of dry efficiency of the dryer <NUM>. The filter unit <NUM> may be placed on the base <NUM>.

Referring both <FIG> and <FIG>, when the filter unit <NUM> is removed and the dehumidification unit <NUM> is mounted in the dryer <NUM>, the closed flow path may be changed to an open flow path. Accordingly, the dryer <NUM> may perform a dehumidification operation (dehumidification mode). That is, the dryer may be switched from the dry mode to the dehumidification mode.

Referring to <FIG> and <FIG>, the dehumidification mode creates an open flow path for air brought in from outside to pass through the heat exchanger <NUM> and the drum <NUM> and flow back to the outside. Air flows in the dehumidification mode and air flows according to drum control in the dehumidification mode will now be described with reference to <FIG> and <FIG>.

Referring to <FIG>, the dehumidification unit <NUM> may be arranged on the base <NUM>. Specifically, the dehumidification unit <NUM> may be detachably mounted on the base <NUM>.

Especially, as the dehumidification unit <NUM> is installed in the dryer <NUM>, the dryer <NUM> may have an open flow path. The open flow path may be an air movement path (see arrows of <FIG>) formed for the outside air to be sucked into the dryer <NUM>, pass through the heat exchanger <NUM> and the drum <NUM>, and be discharged out of the dryer <NUM>. Alternatively, the open flow path may be an air movement path formed for the outside air to be sucked into the dryer <NUM>, pass through the heat exchanger <NUM>, and be discharged out of the dryer <NUM>. An inlet port (not shown) and an outlet port (not shown) at both ends of the dehumidification unit <NUM> are connected to the outside of the main body <NUM>, forming an open loop of a flow of air.

Humid outside air, i.e., air before dehumidification, may flow to the inside of the body <NUM> of the dehumidification unit <NUM> through the inlet port of the dehumidification unit <NUM>. The air brought in may pass through an outlet (not shown) along a flow-in path formed in the body <NUM>. The air having passed through the outlet may pass through the heat exchanger <NUM>. Specifically, the air having passed the outlet may exchange heat with an evaporator <NUM> and a condenser <NUM> while passing through the evaporator <NUM> and the condenser <NUM>. Accordingly, the air that has passed through the heat exchanger <NUM> may turn hot and dry air. Herein, 'hot' means having relatively high temperature than the air before passing through the heat exchanger <NUM> and does not mean absolutely hot. The air from which moisture is removed while passing the heat exchanger <NUM> may pass the flow-in port <NUM> of the drum <NUM>, the inside <NUM> of the drum and the flow-out port <NUM>, and flow into the body <NUM> of the dehumidification unit <NUM> through a flow-in port <NUM> of the dehumidification unit <NUM>. In this case, the fan <NUM> may be arranged in a flow path connecting between the flow-out port <NUM> of the drum <NUM> and the flow-in port of the dehumidification unit <NUM>. The fan <NUM> may facilitate the dehumidified air to move smoothly. The air flowing into the body <NUM> may pass through the outlet port along a discharge flow path (not shown) of the dehumidification unit <NUM>, and may be discharged out of the main body <NUM>. As a result, the air before dehumidification flows into the dryer <NUM> from outside and may be dehumidified by exchanging heat with the heat exchanger <NUM>, and the dehumidified air may be discharged out of the dryer <NUM>. With the flows of air, the humidification operation (humidification mode) may be performed.

Referring to <FIG>, the dryer <NUM> according to the disclosure controls the driving motor <NUM> to rotate the drum <NUM> in the dehumidification mode. In general, the dryer <NUM> rotates the drum <NUM> to lift and drop the object with the plurality of lifters <NUM> so that the object contacts hot air while drifting in the space in the drum <NUM> in the dry mode.

Assuming that the drum <NUM> is rotated at a first rotation speed in the dry mode, the dryer <NUM> controls the driving motor <NUM> to rotate the drum <NUM> at a second rotation speed in the dehumidification mode. For example, in the dehumidification mode, the rotation speed of the drum <NUM> may be <NUM> revolutions per minute (rpm) to <NUM> rpm. However, it is noted that the rotation speed in the dehumidification mode is not always different from the speed in the dry mode or limited to the aforementioned examples of numerical values but may be various rotation speeds depending on the temperature and outside environment (indoor temperature, indoor humidity) in the drum <NUM>.

As shown in <FIG>, the drum <NUM> may be rotated in the dehumidification mode <NUM>. Assuming that the drum <NUM> is in the stopped state in the dehumidification mode, the air flowing out through the flow-in port <NUM> is concentrated on a certain place on the surface of the drum <NUM>. However, when the drum <NUM> is rotated, the air flowing in through the flow-in port <NUM> is uniformly distributed on the surface of the drum <NUM> due to the rotation of the drum <NUM>.

<FIG> is a control block diagram of a dryer, according to an embodiment.

The input module <NUM> allows the user to select a mode through rotation of a dial, a button input, or a display touch input. In the embodiment, the input module <NUM> may provide an interface to select the dry mode or the dehumidification mode. Upon receiving a selection of the dry mode or the dehumidification mode from the user, the input module <NUM> sends a corresponding control signal to a controller <NUM>.

The display 17b displays an operation state and/or a user manipulation state of the dryer <NUM>.

The controller <NUM> may include a memory (not shown) for storing a program and data for controlling operation of the dryer <NUM>, and a processor (not shown) for generating control signals to control the operation of the dryer <NUM> according to the program and data stored in the memory.

Upon receiving a command for the dehumidification mode through the input module <NUM>, the controller <NUM> determines whether outside air is allowed to flow in through a flow path formed by the fan <NUM>. For example, the controller <NUM> may determine through a door sensor <NUM> that the door <NUM> is in an open state, and may generate a control signal to form the open flow path to perform the dehumidification mode. Furthermore, when the dehumidification unit <NUM> is installed in the dryer <NUM> and the door <NUM> is closed, the controller <NUM> may determine through a guide sensor <NUM> whether the dehumidification unit <NUM> has formed the open flow path. In this case, the controller <NUM> may generate a control signal to perform the dehumidification mode.

When the controller <NUM> determines that the open flow path is formed in the dryer <NUM> to allow the dehumidification mode to be performed, the controller <NUM> may control the drum <NUM>, the heat exchanger <NUM> and/or the fan <NUM> to be operated.

When the dehumidification mode is performed, the controller <NUM> controls the drum <NUM> to be rotated by providing a current to the driving motor <NUM> (see <FIG>). As the drum <NUM> is rotated, the temperature in the drum <NUM> rises, thereby increasing dehumidification effects.

The controller <NUM> applies a current to the driving motor <NUM> for a preset period of time to rotate the drum <NUM> until the end of the dehumidification mode.

The fan <NUM> may share the driving power of the driving motor <NUM> supplied to the drum <NUM>, and may be rotated along with the rotation of the drum <NUM>. Alternatively, by adding a device such as an extra clutch (not shown) onto the base <NUM> or arranging the driving motor <NUM> in the plural, the fan <NUM> may be arranged to be separately rotated from the drum <NUM>.

The heat exchanger <NUM> may exchange heat with air and may include the evaporator <NUM> (see <FIG>) and the condenser <NUM> (see <FIG>).

When the dehumidification mode is performed, the controller <NUM> may dehumidify humid outside air through the refrigerant cycle of the heat exchanger <NUM>. In this case, the controller <NUM> may control a rate of the compressor <NUM> (see <FIG>) to control the temperature in the drum <NUM>.

When the dehumidification mode is performed, the controller <NUM> may control the compressor <NUM> such that that the temperature in the drum <NUM> has a lower value than in the dry mode. For example, the compressor <NUM> may be controlled such that the temperature in the drum <NUM> is <NUM> degrees when the dryer <NUM> is in the dry mode and <NUM> degrees in the dehumidification mode. The controller <NUM> may control the temperature in the drum <NUM> to be maintained at a relatively low value, so that the temperature outside the dryer <NUM> does not deviate from the room temperature if possible. Such a temperature is merely an example, and may be set to various values depending on the external environment (temperature or humidity) of the dryer <NUM>.

Furthermore, when the dehumidification mode is performed, the controller <NUM> may control the driving motor <NUM> such that the rotation speed of the fan <NUM> has a lower value than in the dry mode. For example, the magnitude of a current applied to the driving motor <NUM> may be controlled such that the rotation speed of the driving motor <NUM> is XXX in the dry mode and YYY in the dehumidification mode. As described above, as the drum <NUM> shares the driving power from the driving motor <NUM>, a driving source for the fan <NUM>, with the fan <NUM>, the rotation speed of the drum <NUM> may depend on the rotation speed of the fan <NUM>.

The controller <NUM> may control the rotation speed of each of the drum <NUM> and the fan <NUM> to have a lower value than in the dry mode, thereby preventing the outside temperature from deviating from the room temperature. Specifically, as the rotation speed of the drum <NUM> increases, the temperature in the drum <NUM> rises and the air discharged out of the dryer <NUM> may have a higher temperature value than the room temperature. Furthermore, as the rotation speed of the fan <NUM> increases, the volume of air discharged through the flow path increases, contributing to a rise in temperature outside the dryer <NUM>.

Accordingly, when the dehumidification mode is performed, the controller <NUM> controls the driving motor <NUM> such that the rotation speed of the driving motor <NUM> has a lower value than the rotation speed in the dry mode. Such a condition is merely an example, and may be set to have various values depending on the external environment (temperature or humidity) of the dryer <NUM>.

The compressor <NUM> compresses the refrigerant, and convey the compressed refrigerant to the condenser <NUM>. The compressor <NUM> may be implemented as an inverter compressor having variable dry volume, without being limited thereto. For example, the compressor <NUM> is operated by rotating a motor equipped therein based on an operation frequency provided from the controller <NUM>.

Increasing the number of revolutions of the compressor <NUM> may produce hot air sooner. The controller <NUM> may control the operation frequency of the compressor <NUM> based on at least one of a setting of a dry course, a drying period of time, temperature of air in the drum <NUM> and temperature of the compressor.

Configuration and associated operations of the dryer <NUM> have thus far been described with reference to <FIG>. Based on the aforementioned configuration, a control procedure for performing the dehumidification mode of the dryer <NUM> will now be described in detail.

<FIG> is a flowchart of a method of controlling a dryer, according to an embodiment.

The controller <NUM> receives a dehumidification mode, in <NUM>. The input module <NUM> receives an input from the user to perform the dehumidification mode and sends a control signal for the dehumidification mode to the controller <NUM>.

On receiving a command to select the dehumidification mode from the user, the controller <NUM> controls the fan <NUM> to force the air brought in from outside to pass the drum <NUM> and flow out, in <NUM>. Air flows in such a manner that humid outside air flows through an open flow path back to the outside through a dehumidification procedure of the dryer. The air may flow in various paths. In this case, the paths have in common that humid outside air passes the drum <NUM> via the heat exchanger <NUM>, but may slightly differ depending on whether the dehumidification unit <NUM> is installed. Specifically, when the dehumidification unit <NUM> is not installed, the air is moved and discharged in a direction from the front opening of the drum <NUM> to the heat exchanger <NUM> to the flow-in port <NUM> to the drum <NUM> to the front opening. When the dehumidification unit <NUM> is installed, the air is moved and discharged from an inlet port <NUM> of the dehumidification unit <NUM> to the heat exchanger <NUM> to the flow-in port <NUM> to the drum <NUM> to an outlet port <NUM>.

The controller <NUM> controls the driving motor <NUM> to rotate the drum <NUM> when the dehumidification mode of the dryer <NUM> is started. The humid air brought in from outside is subject to a stirring action of being mixed with dry air inside due to rotation of the drum <NUM>. Hence, remaining moisture in the drum <NUM> may be evaporated faster than when the drum <NUM> is not rotated. Furthermore, when the drum <NUM> is rotated, temperature in the drum <NUM> rises and thus, humidity in the drum <NUM> may be evaporated at relatively high speed.

The air that has passed the heat exchanger <NUM> is concentrated on a certain area on the surface of the drum <NUM> through the flow-in port <NUM> when the drum <NUM> is not rotated, but the air may be uniformly distributed on the entire surface of the drum <NUM> when the drum <NUM> is rotated.

The controller <NUM> controls the driving motor <NUM> to rotate the drum <NUM> at a preset speed. In this case, the preset speed may be set based on the rotation speed of the drum <NUM> in the dry mode.

In an embodiment, the controller <NUM> may control the driving motor <NUM> to rotate the drum <NUM> at a second rotation speed in the dehumidification mode, which is lower than a first rotation speed in the dry mode. The temperature in the drum <NUM> may increase as the drum <NUM> rotates faster. Taking this into account, the controller <NUM> may control the temperature in the drum <NUM> to be maintained at a relatively low value, so that the temperature outside the dryer <NUM> does not deviate from the room temperature if possible. Furthermore, the dryer <NUM> may have lower noise from rotation of the drum in the dehumidification mode than in the dry mode.

Moreover, in an embodiment, the controller <NUM> may control the driving motor <NUM> to rotate the drum <NUM> at a second rotation speed in the dehumidification mode, which is higher than the first rotation speed in the dry mode. In this case, the dryer <NUM> may allow the air in the drum <NUM> to be discharged relatively faster.

The drum <NUM> continues to rotate until the end of the dehumidification mode for a preset period of time from when the dehumidification is started by being selected by the user. When the preset period of time has elapsed in <NUM>, the dehumidification mode is terminated along with stopping of the drum <NUM>.

In the meantime, in the disclosure, in addition to controlling rotation of the drum <NUM> to increase the dehumidification efficiency, the compressor may be controlled to increase the temperature in the drum <NUM>. This will be further described with reference to <FIG>.

<FIG> is a flowchart of a method of controlling a dryer, according to another embodiment.

The controller <NUM> receives the dehumidification mode, in <NUM>. The input module <NUM> receives an input from the user to perform the dehumidification mode and sends a control signal for the dehumidification mode to the controller <NUM>. Operations of the fan <NUM> related to air flows in the dehumidification mode are the same as what are described above in connection with <FIG> and <FIG>.

On receiving a command to select the dehumidification mode from the user, the controller <NUM> controls the driving motor <NUM> at a second rotation speed lower than a first rotation speed, which is the rotation speed of the drum in the dry mode, in <NUM>. The temperature in the drum <NUM> may increase as the drum <NUM> rotates faster. Taking this into account, the controller <NUM> may control the temperature in the drum <NUM> to be maintained at a relatively low value, so that the temperature outside the dryer <NUM> does not deviate from the room temperature if possible. Furthermore, the dryer <NUM> may have lower noise from rotation of the drum in the dehumidification mode than in the dry mode.

While the dehumidification mode goes on by rotation of the drum <NUM>, the controller <NUM> controls the compressor <NUM> to control the temperature in the drum <NUM>.

Specifically, the controller <NUM> may control the compressor to control the temperature in the drum <NUM> to be a second temperature lower than a first temperature, which is the temperature in the drum <NUM> in the dry mode, in <NUM>. The temperature in the dryer <NUM> is generally higher than the room temperature, and this temperature difference may cause the air in the dryer <NUM> to be condensed into steam. Hence, in the embodiment, the dryer <NUM> may perform additional compressor control to reduce the temperature in the drum <NUM> during the dehumidification mode.

Furthermore, the controller <NUM> may control the temperature in the drum <NUM> by controlling the compressor <NUM> based on the difference between the temperature in the drum <NUM> and the room temperature. When the difference between the temperature in the drum <NUM> and the room temperature is big, the controller <NUM> may control the compressor <NUM> to reduce the difference. Specifically, the controller <NUM> may control heat produced by the compressor <NUM> by controlling the operation frequency of the compressor motor that drives the compressor <NUM>.

Furthermore, the controller <NUM> may control the compressor <NUM> to control the temperature in the drum <NUM> to be a second temperature higher than the first temperature, which is the temperature in the drum <NUM> in the dry mode. Unlike in <NUM>, the operation frequency of the compressor <NUM> is controlled to be higher than in the dry mode to control the temperature in the drum <NUM> to be relatively high. For example, when the outside humidity is higher than usual, the dryer <NUM> may increase dehumidification efficiency of the drum <NUM> by increasing the temperature in the drum <NUM>.

The drum <NUM> continues to rotate until the end of the dehumidification mode for a preset period of time from when the dehumidification is started by being selected by the user. When the preset period of time has elapsed in <NUM>, the dehumidification mode is terminated along with stopping of the drum <NUM> and the compressor <NUM>.

Although not shown in <FIG> and <FIG>, the controller <NUM> may control the dryer <NUM> not to perform the dehumidification mode when there is an object to be dried in the drum <NUM>. The controller <NUM> does not generate a control signal to drive the fan <NUM> while the drum <NUM> contains the object. When there is the object in the drum <NUM>, moisture contained in the outside air may permeate into the object. Furthermore, when the moisture that has evaporated from the object is supplied back to the outside, it makes the dehumidification inefficient. Accordingly, when the current flowing to the driving motor <NUM> exceeds a predetermined current magnitude (a current applied when there is nothing in the drum), the controller <NUM> may hold off the dehumidification mode.

Meanwhile, the embodiments of the disclosure may be implemented in the form of a recording medium for storing instructions to be carried out by a computer. The instructions may be stored in the form of program codes, and when executed by a processor, may generate program modules to perform operations in the embodiments of the disclosure. The recording media may correspond to computer-readable recording media.

The computer-readable recording medium includes any type of recording medium having data stored thereon that may be thereafter read by a computer. For example, it may be a read only memory (ROM), a random access memory (RAM), a magnetic tape, a magnetic disk, a flash memory, an optical data storage device, etc..

Claim 1:
A dryer (<NUM>) comprising:
a main body (<NUM>);
a drum (<NUM>) arranged in the main body (<NUM>) for receiving an object to be dried;
a driving motor (<NUM>) configured to rotate the drum (<NUM>);
an input module (<NUM>) configured to receive an input from a user of a dry mode or a dehumidification mode to dehumidify humid outside air;
a heat exchanger (<NUM>) arranged in the main body (<NUM>);
a compressor (<NUM>) configured to produce hot air;
a fan (<NUM>) configured to form a flow path through which air flows in from outside and air having passed the heat exchanger (<NUM>) and the drum (<NUM>) flows out; and
a controller (<NUM>);
characterized in that the controller (<NUM>) is configured to:
- control the driving motor (<NUM>) to rotate the drum (<NUM>) at a first rotation speed in response to the dry mode being input, and control the driving motor (<NUM>) to rotate the drum (<NUM>) at a second rotation speed different from the first rotation speed in response to the dehumidification mode being input;
- rotate the drum (<NUM>) for air brought in from outside to reach an inner surface of the drum (<NUM>) in response to receiving a command to select the dehumidification mode through the input module (<NUM>);
- control the compressor (<NUM>) for temperature in the drum (<NUM>) to be the first temperature in the dry mode, and control the compressor (<NUM>) for temperature in the drum (<NUM>) to be the second temperature different from the first temperature in the dehumidification mode; and
- generate a control signal to drive the fan (<NUM>) in response to receiving a command to select the dehumidification mode through the input module (<NUM>).