Washing machine and control method thereof

Abstract

The purpose of the present disclosure is to determine a time point at which a drying process is to be terminated, on the basis of the weight of objects to be dried in a washing machine that has a drying function. To this end, the washing machine may comprise: a heater for heating dry air to be supplied into a drum; a temperature sensor for detecting the temperature of the dry air; and a control unit for controlling the operation of the heater in response to activation of the drying function. Various other embodiments are possible.

Description

[Technical Field]

[0001] Various embodiments of the disclosure relate to a washing machine equipped with a drying device, and more particularly to a washing machine and a method thereof that adaptively performs a drying cycle based on a weight of a drying object.[Background Art]

[0002] A drying device is a device that dries clothes by rotating a drum including wet clothes (drying objects) at low speed while supplying hot air heated by a heater into the drum. Recently, a washing machine with a drying device capable of both drying and washing may perform a drying cycle alone or perform a drying cycle after completion of spinning in connection with a washing cycle.

[0003] A washing machine may determine when a drying cycle is performed and terminated according to a type of drying object or a type of washing cycle (washing course). Further, a washing machine may adjust an output of a drying device while a drying cycle is being performed. A washing machine may obtain information for performing a drying cycle and determining a termination point.

[0004] Meanwhile, in case that a drying object is not sufficiently dried, user experience may deteriorate due to insufficient drying. In case that a drying object is excessively dried, damage to the drying object may occur, an interior of the washing machine may overheat, and unnecessary power consumption may occur.[DISCLOSURE OF INVENTION] [Technical Problem]

[0005] Various embodiments of the disclosure may propose a washing machine and a control method that provides optimal drying performance and drying efficiency based on a weight of a drying object during a drying cycle.[Solution to Problems]

[0006] A washing machine according to an embodiment of the disclosure may include a heater heating dry air to be supplied into an interior of a drum, a temperature sensor for sensing a temperature of the dry air, and a controller controlling operation of the heater in response to activation of a drying function. The controller may control whether to operate the heater to maintain constant the temperature of the dry air with respect to a target control temperature in case that a drying cycle is initiated by the activation of the drying function, and terminate the drying cycle in response to arrival of a drying termination time within a preset reference operation section for initiation or termination of the drying cycle. The drying termination time may be identified by a weight of a drying object obtained in response to the activation of the drying function.

[0007] A method for controlling operation of a heater in response to activation of a drying function in a washing machine according to an embodiment of the disclosure may include controlling whether to operate the heater to maintain constant a temperature of dry air with respect to a target control temperature in case that a drying cycle is initiated by the activation of the drying function, and terminating the drying cycle in response to arrival of a drying termination time within a preset reference operation section for initiation or termination of the drying cycle. The drying termination time may be identified by a weight of a drying object obtained in response to the activation of the drying function.[Advantageous Effects]

[0008] A washing machine according to an embodiment of the disclosure may minimize power required for performing a drying cycle.

[0009] A washing machine according to an embodiment of the disclosure may provide drying performance independently of conditions required for drying components or target drying objects.[BRIEF DESCRIPTION OF DRAWINGS]

[0010] FIG. 1 is a cross-sectional view illustrating a washing machine according to an embodiment of the disclosure; FIG. 2 is a block diagram illustrating a washing machine according to an embodiment of the disclosure; FIG. 3 is an operation flowchart for a washing machine to control a drying cycle according to an embodiment of the disclosure; FIG. 4 is an operation flowchart for a washing machine to control a drying cycle according to an embodiment of the disclosure; FIG. 5 is an operation flowchart for a washing machine to control a drying cycle according to an embodiment of the disclosure; and FIG. 6 is a graph illustrating a current of a switching signal for operating a heater during a drying cycle and a graph illustrating temperature change of dry air according to an embodiment of the disclosure.

[0011] In relation to the description of the drawings, the same or similar reference numerals may be used for the same or similar components.[MODE FOR THE INVENTION]

[0012] Hereinafter, embodiments of the disclosure are described in detail with reference to the drawings so that those skilled in the art to which the disclosure pertains may easily practice the disclosure. However, the disclosure may be implemented in other various forms and is not limited to the embodiments set forth herein. The same or similar reference denotations may be used to refer to the same or similar elements throughout the specification and the drawings. Further, for clarity and brevity, no description is made of well-known functions and configurations in the drawings and relevant descriptions.

[0013] Further, the terms to be described below is defined as follows. Laundry introduced into washing machine 1 and disposed inside drum 12 before washing, rinsing, and spinning cycles are performed is referred to as "washing object." Laundry before washing machine 1 performs a drying cycle to dry the washing object is referred to as "drying object." The drying object that has been dried after washing machine 1 completes the drying cycle is referred to as "dried laundry." The mentioned terms may be used interchangeably as necessary, but in cases of a transition state between at least two states among "washing object," "drying object," and "dried laundry," or cases that do not correspond to any of the three states, they may be collectively referred to as "laundry."

[0014] FIG. 1 is a cross-sectional view illustrating a washing machine 1 according to an embodiment. In other words, FIG. 1 may be understood as a cross-sectional view cut in one direction to show a configuration of a washing machine equipped with a drying device 40.

[0015] Referring to FIG. 1, the washing machine 1 may include a drying device 40 for drying a drying object. Hereinafter, the washing machine 1 according to the disclosure is described focusing on a front-load type washing machine but, without limitations thereto, may be applied to a washing machine equipped with a pulsator and a drying device 40. In other words, the washing machine 1 may include a front-load type washing machine or a top-load type washing machine.

[0016] According to an embodiment, the washing machine 1 may include a drum-type tub 11 provided inside a main body 10 for storing water (e.g., washing water and rinsing water), and a drum 12 rotatably provided inside the tub 11 and having a plurality of drain holes formed therein.

[0017] According to an embodiment, a driving motor 13 that rotates the drum 12 and / or a pulsator (e.g., the pulsator 210 of FIG. 3) in forward or reverse directions to perform washing, rinsing, and spinning operations may be provided at a lower portion of the tub 11. The driving motor 13 may generate torque for rotating the drum 12 and / or the pulsator 210. One surface (e.g., an inner surface) of the drum may be connected to a rotation shaft of the driving motor 13.

[0018] According to an embodiment, the pulsator 210 may be rotatably provided on an inner surface of the drum 12. The pulsator 210 may rotate independently of the drum 12. In other words, the pulsator 210 may rotate in the same direction as the drum 12 or in a different direction. The pulsator 210 may rotate at the same speed as the drum 12 or at a different speed.

[0019] According to an embodiment, one or more driving motors 13 may be provided.

[0020] For example, in case that one driving motor 13 is provided, the driving motor 13 may be connected to the drum 12, the pulsator 210, and a blowing fan 41. The driving motor 13 may drive the drum 12, the pulsator 210, and the blowing fan 41 together.

[0021] For example, in case that multiple driving motors 13 are provided, the driving motors 13 may be connected to the drum 12, the pulsator 210, and the blowing fan 41, respectively. Each driving motor 13 may drive the connected drum 12, pulsator 210, and blowing fan 41.

[0022] According to an embodiment, a washing water heater 16 that heats water (e.g., washing water) to be supplied into the tub 11 corresponding to a temperature of washing water to be used in a washing cycle may be provided inside a lower portion of the tub 11.

[0023] According to an embodiment, an opening 14 may be formed at the front of the tub 11 and the drum 12 so that a user may remove laundry from the front of the main body 10. A door 15 for opening and closing the opening 14 may be provided at the front of the main body 10. The door 15 may be hingedly coupled to one side of the front of the main body 10. The door 15 may open and close the opening 14 by rotating around the one side of the front of the main body 10 as an axis.

[0024] According to an embodiment, a detergent supply device 18 for supplying detergent and a water supply portion 20 for supplying washing water and rinsing water may be provided at an upper portion of the tub 11.

[0025] For example, the detergent supply device 18 may be divided into one space or multiple spaces inside. The detergent supply device 18 may be provided on the front of the main body 10 for easy introduction of detergent and rinse aid. Detergent or rinse aid may be stored in the divided multiple spaces.

[0026] According to an embodiment, the water supply portion 20 may include a water supply pipe 22 that supplies water and a water supply valve 24 installed in the water supply pipe 22 to control water supply of the water supply pipe 22. The water supply pipe 22 may be connected to the detergent supply device 18 so that water supplied from outside may be supplied toward the detergent supply device 18. For the detergent in the detergent supply device 18 to be supplied to the tub 11 in a dissolved state in water, a separate connection pipe 26 may be provided between the detergent supply device 18 and the tub 11 so that water passing through the detergent supply device 18 may be supplied to the tub 11 together with detergent, and a water supply nozzle 28 may be provided at an outlet of the connection pipe 26.

[0027] According to an embodiment, the washing machine 1 may include a drainage portion 30 for draining water inside the tub 11. The drainage portion 30 may include a drainage pipe 31 connected to a lower portion of the tub 11 to guide water in the tub 11 to the outside, and a drainage pump 32 installed in the drainage pipe 31.

[0028] According to an embodiment, the washing machine 1 may include a drying device 40. The drying device 40 may include a blowing fan 41 installed at an upper portion of the tub 11, a drying duct 42 connecting between a discharge port 41b of the blowing fan 41 and an air inlet 45 formed above the opening 14 of the tub 11, a condensation duct 43 mounted at the rear of the tub 11 to connect between an air outlet 46 formed at a lower rear portion of the tub 11 and an intake port 41a of the blowing fan 41, and a heater 44 installed inside the drying duct 42 to generate high-temperature air supplied into the drum 12.

[0029] According to an embodiment, a spray nozzle 47 that sprays condensation water (cold water) into the condensation duct 43 may be provided at an upper inner portion of the condensation duct 43 so that moisture may be condensed and removed as high-temperature and high-humidity air generated through drying of the drying object passes through the condensation duct 43. The spray nozzle 47 may be connected to the water supply portion 20 through a condensation water supply pipe 48 and a condensation water valve 49 to supply condensation water.

[0030] According to an embodiment, a spray nozzle 47 that sprays condensation water (cold water) into the condensation duct 43 may be provided at an upper inner portion of the condensation duct 43 so that moisture may be condensed and removed as high-temperature and high-humidity air generated through drying of the drying object passes through the condensation duct 43. An outlet 43a for discharging condensed water may be formed at a lower side of the condensation duct 43. Condensation water discharged through the outlet 43a may flow into a drainage pipe 31 of the drainage portion 30.

[0031] An example of operation of the washing machine 1 equipped with the drying device 40 is as follows.

[0032] According to an embodiment, the washing machine 1 may perform at least one of a washing cycle, a rinsing cycle, a spinning cycle, and a drying cycle. By user selection, the washing machine 1 may perform only one of a washing cycle, a rinsing cycle, a spinning cycle, and a drying cycle, or may perform a combination of at least two of a washing cycle, a rinsing cycle, a spinning cycle, and a drying cycle. The example to be described below may be understood as a case where the washing machine 1 performs all of a washing cycle, a rinsing cycle, a spinning cycle, and a drying cycle in sequence.

[0033] As a washing cycle begins, in case that the water supply valve 24 of the water supply device 20 opens, water (washing water) may be supplied to the tub 11 after passing through the water supply pipe 22 and the detergent supply device 18. In case that water supply is completed, the washing water heater 16 is operated to heat the washing water filled in the tub 11 to a temperature required for washing, and then the drum 12 rotates forward or backward by driving the driving motor 13, and a washing cycle may be performed by friction with the drum 12 and decomposition force of detergent.

[0034] As the washing cycle ends, a rinsing cycle may begin. The washing machine 1 may repeat spinning and water supply in the rinsing cycle. As the rinsing cycle ends, a spinning cycle may be performed. The washing machine 1 may operate the driving motor 13 at high speed in the spinning cycle to rotate the drum 12 at high speed.

[0035] As the spinning cycle ends, a drying cycle may begin. The washing machine 1 may operate the driving motor 13 at low speed to rotate the drum 12 at low speed. The washing machine 1 may operate the heater 44 and the blowing fan 41 so that air inside the drum 12 is drawn toward the blowing fan 41 through the condensation duct 43, and then circulated to be discharged back into the drum 12 through the drying duct 42. Accordingly, air in the drying duct 42 is heated by the heater 44 and flows into the drum 12 in a high-temperature dry state, and the drying object inside the drum 12 is heated by the high-temperature dry air (hot air), causing moisture included in the drying object to evaporate and be dried. In this case, air in the drying duct 42 is heated by the heater 44 and flows into the drum 12 in a high-temperature dry state, and the drying object inside the drum 12 is heated by the high-temperature dry air (hot air), causing moisture included in the drying object to evaporate and be dried. As the drying cycle progresses, the high-temperature dry air absorbs moisture from the drying object and changes to high-temperature humid air which is transferred to the condensation duct 43, and the high-temperature humid air transferred to the condensation duct 43 contacts condensation water (cold water) sprayed through the spray nozzle 47 to be condensed and changed to dry air, and the drying object may be dried by repeating the process of heating this dry air again in the heater 44 and flowing it into the drum 12.

[0036] FIG. 2 is a block diagram illustrating a washing machine 100 (e.g., the washing machine 1 of FIG. 1) according to an embodiment. At least some components of FIG. 2 may correspond to components illustrated in FIG. 1.

[0037] Referring to FIG. 2, a user interface 121 may include a user input for obtaining an input for an operation command of the washing machine 100. The input portion may be implemented as buttons (not illustrated) provided on an upper front portion of the main body (e.g., the main body 10 of FIG. 1). The buttons may include touch-type buttons or dial-type buttons.

[0038] For example, the input portion may receive preset operation methods for washing, rinsing, spinning, or drying cycles from a user. The input portion may receive commands for the number of times or operation time for the cycles from a user.

[0039] According to an embodiment, the input portion may transmit received information to a controller 110.

[0040] According to an embodiment, the user interface 121 may include an output portion for visually or audibly outputting operation information. The output portion may be implemented as a display (not illustrated) provided on an upper front portion of the main body 10. The display may be implemented as a light emitting diode (LED), an organic light emitting diode (OLED), or a liquid crystal display (LCD).

[0041] According to an embodiment, the output portion may visually output information obtained by the input portion.

[0042] For example, the output portion may visually output remaining execution time for the cycles.

[0043] For example, the output portion may also include a speaker for audibly outputting operation information. The output portion may output guide voices announcing the start or end of the cycles through the speaker.

[0044] According to an embodiment, the controller 110 may transmit information or control signals to be output to the output portion.

[0045] According to an embodiment, the user interface 121 may be implemented as a touch screen panel that simultaneously performs input and output functions.

[0046] According to an embodiment, a temperature sensor 123 may sense a temperature of air or water. The temperature sensor 123 may include a thermistor. The temperature sensor 123 may transmit an electrical signal corresponding to an electrical resistance value that changes with temperature of the thermistor to the controller 110.

[0047] According to an embodiment, multiple temperature sensors 123 may be implemented and provided at positions where temperature is to be sensed.

[0048] For example, the temperature sensor 123 may sense a temperature of washing water (or rinsing water) supplied inside the drum (e.g., the drum 12 of FIG. 1) during a washing cycle (or rinsing cycle).

[0049] For example, the temperature sensor 123 may sense a temperature of dry air (hot air) supplied to the drum 12 during a drying cycle. The temperature sensor 123 may be provided on the drying duct (e.g., the drying duct 42 of FIG. 1) or on the air inlet (e.g., the air inlet 45 of FIG. 1).

[0050] For example, the temperature sensor 123 may sense a temperature of dry air (hot air) discharged from the drum 12 during a drying cycle. The temperature sensor 123 may be provided on the drying duct 42 or on the air outlet (e.g., the air outlet 46 of FIG. 1).

[0051] According to an embodiment, based on information about temperature sensed by the temperature sensor 123, the controller 110 may control operation of the heater 44. The controller 110 may operate or stop operating the heater 44 so that the temperature satisfies a preset range based on a temperature inside the drum 12 or of the dry air.

[0052] According to an embodiment, a current sensor 125 may sense current flowing through a driving motor 13 (e.g., the driving motor 13 of FIG. 1) and transmit the corresponding current signal to the controller 110. The controller 110 may sense a weight of a drying object (or washing object) or sense a degree of drying of the drying object (or washing object) based on a current signal obtained from the current sensor 125.

[0053] For example, the controller 110 may repeatedly turn on / off the driving motor 13 to rotate the drum 12 and / or the pulsator 210. A weight of laundry may be measured based on a back electromotive force value generated in case that the driving motor 13 is turned off.

[0054] For example, the controller 110 may transmit a signal to the driving unit 200 to rotate the drum 12 and / or the pulsator 210 at a target operating speed, and may measure a weight of laundry based on time required for the drum 12 and / or the pulsator 210 to reach the target operating speed.

[0055] For example, the controller 110 may also measure a load inside the drum 12 based on a sensing value obtained from the driving motor 13.

[0056] Without limitation to the above-described method, the washing machine 100 may measure a load inside the drum 12 through various other methods. For example, the washing machine 1 may also measure a weight of laundry from information obtained from a weight measurement sensor provided below the drum 12.

[0057] According to an embodiment, the controller 110 may control the overall operation of the washing machine 1. The controller 110 may transmit information necessary for operation of the washing machine 1 or output information about an operation state of the washing machine 1.

[0058] According to an embodiment, the controller 110 may include a processor 111 that generates control signals for controlling operation of the washing machine 1 and memory 113 for storing or saving programs or data for generating the control signals. Hereinafter, control signals generated from the controller 110 may be understood as control signals generated by the processor 111.

[0059] According to an embodiment, at least some of the processor 111, the memory 113, and a timer 115 may be configured independently of the controller 110 or may be implemented integrally.

[0060] According to an embodiment, the processor 111 and the memory 113 may be implemented as separate chips or as a single chip. For example, the processor 111 may be implemented as a single processor or at least multiple processors, and the memory 113 may be implemented as one or multiple (e.g., volatile memory or nonvolatile memory).

[0061] According to an embodiment, the memory 113 may store or save programs and data for controlling operation of the washing machine 1.

[0062] For example, the memory 113 may store a course of a drying cycle according to a course of a selected washing cycle. For example, according to a type of course of a drying cycle, a total time for the washing machine 100 to perform a drying cycle, that is, time or operating power for the washing machine 100 to operate the heater 44, the blowing fan 41, the drum 12 and / or the pulsator 210 to perform a drying cycle may be stored. Here, the total time for the washing machine 100 to perform a preset drying cycle may be referred to as "target drying time" or "reference operation section."

[0063] For example, a setting value for a target operation time of the heater 44 according to a weight of a drying object may be stored in the memory 113 as a database (DB). The database may be stored in the memory 113 as a table of target operation times corresponding to weights of drying objects.

[0064] For example, a range of set temperatures inside the drum 12 according to a type of drying cycle (e.g., course of drying cycle) may be stored in the memory 113.

[0065] For example, an operation time of an additional drying cycle according to occurrence of an event for performing an additional drying cycle may be stored in the memory 113.

[0066] According to an embodiment, the memory 113 may store a user input received through the input portion or store information about operation of the washing machine 1 (e.g., remaining time for each cycle of the washing machine).

[0067] According to an embodiment, the timer 115 may count an operation time of the washing machine 1. The timer 115 may be implemented in hardware and provided as a separate module, or implemented in software and provided integrally with the controller 110.

[0068] According to an embodiment, the timer 115 may count time for operations where the washing machine 1 performs washing, rinsing, spinning, or drying cycles.

[0069] According to an embodiment, the timer 115 may count time during which the heater 44 operates during a drying cycle. For example, in case that the heater 44 repeatedly operates and stops operating, the timer 115 may count only the time during which the heater 44 operates.

[0070] According to an embodiment, the controller 110 may determine whether time counted by the timer 115 exceeds a preset target operation time. For example, the controller 110 may determine whether time during which the heater 44 has operated exceeds a preset target operation time. In case that the preset target operation time is exceeded, the controller 110 may terminate the drying cycle.

[0071] According to an embodiment, the controller 110 may control the overall operation of the washing machine 1. For example, the controller 110 may control to perform washing, rinsing, spinning, or drying cycles.

[0072] For example, the controller 110 may heat dry air supplied into the drum 12 to perform a drying cycle. To that end, the controller 110 may operate the heater 44 for a predetermined time.

[0073] For example, the controller 110 may operate the blowing fan 41 to supply dry air into the drum 12. Accordingly, dry air may be supplied into the drum 12 through the discharge port (e.g., the discharge port 41b of FIG. 1) of the blowing fan 41 and through the air inlet (e.g., the air inlet 45 of FIG. 1). The dry air may pass through the drum 12 and high-temperature humid air may be discharged through the air outlet (e.g., the air outlet 46 of FIG. 1).

[0074] According to an embodiment, the controller 110 may transmit control signals for operating components connected to the driving unit 200.

[0075] According to an embodiment, the driving unit 200 may be drivingly connected to the driving motor 13. The driving motor 13 may be connected to the drum 12, the pulsator 210, or the blowing fan 41 to operate the drum 12, the pulsator 210, or the blowing fan 41.

[0076] According to an embodiment, the controller 110 may determine a target operation time of the heater 44 to be operated during a drying cycle. The controller 110 may obtain a weight of a drying object before the drying cycle is performed. The drying object may be understood as laundry after washing, rinsing, and spinning cycles have been completed. The weight of the drying object may be referred to as a first weight.

[0077] According to an embodiment, the controller 110 may determine a target operation time of the heater 44 based on the first weight. For example, the controller 110 may determine a preset target operation time according to the first weight based on a database stored in the memory 113. The database may be understood as, e.g., a table in which a relationship between the first weight and the target operation time is set. The first weight and the target operation time may be linearly proportional.

[0078] According to an embodiment, the controller 110 may operate the heater 44 to heat dry air supplied into the drum 12 during a drying cycle. The controller 110 may transmit a control signal to the heater 44. For example, the control signal may be a switching signal. The switching signal may be a pulse signal having a predetermined current value that turns on (switching-on) or turns off (switching-off) the heater 44. The heater 44 that has received the control signal may repeat operation and stopping operation.

[0079] According to an embodiment, the controller 110 may operate or stop operating the heater 44 so that a temperature inside the drum 12 and / or a temperature of the dry air satisfies a preset temperature range during a drying cycle. To that end, the controller 110 may obtain a temperature inside the drum 12 or of the dry air from the temperature sensor 123.

[0080] For example, the controller 110 may repeat an operation cycle multiple times of operating the heater 44 for a predetermined time and then stopping operation for a predetermined time. Here, a predetermined time during which the heater 44 operates during a drying cycle may be referred to as "unit operation time," and a predetermined time during which operation stops after the unit operation time may be referred to as "unit idle time." The unit operation time and the unit idle time may be referred to as a "unit operation cycle."

[0081] For example, during a drying cycle, the heater 44 may be repeated for n unit operation cycles. The unit operation cycles may be composed of a first unit operation cycle, a second unit operation cycle, ..., a kth unit operation cycle, ..., an nth operation cycle in chronological order. Here, k and n are natural numbers of 1 or more, and n may be a natural number greater than or equal to k.

[0082] For example, the first unit operation cycle may include a first unit operation time and a first unit idle time.

[0083] For example, the second unit operation cycle may include a second unit operation time and a second unit idle time.

[0084] For example, the kth unit operation cycle may include a kth unit operation time and a kth unit idle time.

[0085] For example, the nth unit operation cycle may include an nth unit operation time and an nth unit idle time.

[0086] According to an embodiment, unit operation times and unit idle times constituting each unit operation cycle may be the same or different from each other.

[0087] According to an embodiment, as a drying cycle progresses, time of a unit operation cycle may decrease. In other words, as a drying cycle progresses, time for a temperature of dry air to reach a threshold range may decrease.

[0088] According to an embodiment, the controller 110 may operate the heater 44 for a unit operation time and then stop operation for a unit idle time so that a temperature of dry air satisfies a threshold range, and the controller 110 may count a total sum of unit operation times during which the heater 44 operates using the timer 115. A set of unit operation times may be referred to as "cumulative operation time."

[0089] According to an embodiment, the controller 110 may compare the cumulative operation time with the target operation time. The controller 110 may terminate a drying cycle in response to the cumulative operation time exceeding the target operation time.

[0090] According to an embodiment, a total sum of unit operation cycles may be less than or equal to time during which a drying cycle is substantially performed. In other words, the washing machine 1 may additionally perform a drying cycle for a predetermined time in case that a specific event occurs after the nth unit operation cycle ends. Specific events for additionally performing a drying cycle are described in detail in FIG. 4 and below.

[0091] According to an embodiment, because the controller 110 operates until the cumulative operation time of the heater 44 reaches the target operation time during a drying cycle, a termination point of the drying cycle may be determined without having a separate sensor. Because the controller 110 controls the heater 44 to operate so that the cumulative operation time reaches the target operation time during a drying cycle, the washing machine 100 may provide drying performance independently of factors affecting the drying cycle (e.g., amount of moisture included in laundry, temperature of cold water supplied into the condensation duct 43).

[0092] According to an embodiment, because the controller 110 operates until the cumulative operation time of the heater 44 reaches the target operation time, a drying cycle may be terminated at a point earlier than in case that a preset target drying time elapses. Accordingly, considering that most of the power consumed during a drying cycle is electrical energy required to operate the heater 44, the washing machine 100 may minimize power required to perform a drying cycle independently of factors affecting the drying cycle.

[0093] FIGS. 3 to 5 are operation flowcharts for the washing machine 1 (e.g., the washing machine 1 of FIG. 1 or the washing machine 100 of FIG. 2) to control a drying cycle according to an embodiment.

[0094] Referring to FIGS. 3 to 5, each control operation may be repeatedly performed as necessary, or some operations may be omitted. Further, the order of the control operations may be changed as necessary.

[0095] FIG. 3 is an operation flowchart for the washing machine 1 to control a drying cycle according to an embodiment.

[0096] According to an embodiment, the washing machine 1 may sense a weight of a drying object in operation 310.

[0097] For example, operation 310 may be performed after the washing machine 1 sequentially performs washing, rinsing, and spinning cycles. Here, the drying object may be understood as laundry that is introduced into the drum (e.g., the drum 12 of FIG. 1) and will undergo a drying cycle after washing, rinsing, and spinning cycles are performed.

[0098] For example, operation 310 may be performed independently of washing, rinsing, and spinning cycles. Here, the drying object may be understood as laundry on which a drying cycle is performed.

[0099] According to an embodiment, to sense a weight of a drying object, the washing machine 1 may obtain a current signal of the driving motor (e.g., the driving motor 13 of FIG. 1) obtained from the current sensor (e.g., the current sensor 125 of FIG. 2). The washing machine 1 may obtain a weight of the drying object based on a back electromotive force value generated in case that the driving motor 13 rotates the drum 12 and / or the pulsator (e.g., the pulsator 210 of FIG. 2). The weight of the drying object may be referred to as a first weight.

[0100] According to an embodiment, the washing machine 1 may determine a target operation time for operating the heater (e.g., the heater 44 of FIG. 1) based on the first weight in operation 320. Here, the target operation time may be understood as a time for which the washing machine 1 intends to operate the heater 44 in total during a drying cycle.

[0101] According to an embodiment, the target operation time may be proportional to the first weight. In other words, as a weight of a drying object sensed by the washing machine 1 increases, the target operation time may increase. For example, the target operation time may be linearly proportional to the first weight.

[0102] According to an embodiment, the washing machine 1 may retrieve a preset target operation time based on the first weight from the memory (e.g., the memory 113 of FIG. 2). The preset target operation time based on the first weight may be stored in the memory 113 in the form of a table.

[0103] According to an embodiment, the target operation time may be shorter than an initially preset time for which a drying cycle is performed.

[0104] According to an embodiment, the washing machine 1 may determine the target operation time based on a weight at the time when laundry was introduced into the drum before a washing cycle is performed (this is referred to as a third weight) and the first weight. In other words, the washing machine 1 may determine the target operation time by comparing the third weight, which is a weight of laundry before a washing cycle is performed, with the first weight.

[0105] For example, the washing machine 1 may predict an amount of moisture included in laundry before and after washing and spinning cycles are performed based on the first weight and the third weight. Accordingly, the washing machine 1 may also determine the target operation time based on the amount of moisture included in the laundry.

[0106] According to an embodiment, the washing machine 1 may operate the heater 44 so that a temperature of dry air satisfies a threshold range in operation 330. The washing machine 1 may operate or stop operating the heater 44 so that a temperature of dry air or the drum 12 satisfies a preset threshold range.

[0107] For example, the washing machine 1 may obtain a temperature of dry air supplied to the drum 12 from the temperature sensor 123. The temperature sensor 123 for obtaining the temperature of dry air may be provided on the drying duct (e.g., the drying duct 42 of FIG. 1) or on the air inlet (e.g., the air inlet 45 of FIG. 1).

[0108] For example, the washing machine 1 may obtain a temperature of dry air discharged from the drum 12 from the temperature sensor 123. The temperature sensor 123 for obtaining the temperature of dry air discharged from the drum 12 may be provided on the drying duct 42 or on the air outlet (e.g., the air outlet 46 of FIG. 1).

[0109] For example, the washing machine 1 may obtain a temperature inside the drum 12 from the temperature sensor 123. The temperature sensor 123 for obtaining the temperature inside the drum 12 may be provided inside the drum 12.

[0110] According to an embodiment, the washing machine 1 may operate or stop operating the heater 44 so that a preset threshold range is satisfied based on a temperature inside the drum 12 and / or of dry air obtained from the temperature sensor 123.

[0111] For example, the washing machine 1 may operate the heater 44 so that a temperature of dry air obtained from the temperature sensor 123 satisfies between a first threshold temperature and a second threshold temperature. For example, the washing machine 1 may operate the heater 44 in case that a temperature of dry air becomes lower than the first threshold temperature, and may stop operating the heater 44 in case that the temperature of dry air becomes higher than the second threshold temperature. Here, time from time t1 in case that the heater 44 is operated because the temperature of dry air becomes lower than the first threshold temperature to time t1' when the heater 44 stops operating because the temperature of dry air becomes higher than the second threshold temperature may be referred to as "(first) unit operation time." At time t2 when the temperature of dry air becomes lower than the first threshold temperature again, the washing machine 1 may operate the heater 44 again. Time from the time t1' to the time t2 may be referred to as "(first) unit idle time." The (first) unit operation time and the (first) unit idle time combined may be referred to as a (first) unit operation cycle.

[0112] According to an embodiment, the washing machine 1 may operate and then stop operating the heater 44 repeatedly at least multiple times. For example, during a drying cycle, the washing machine 1 may operate the heater 44 for n unit operation cycles.

[0113] According to an embodiment, the washing machine 1 may terminate a drying cycle in case that a cumulative time of the heater 44 exceeds the target operation time in operation 340. To that end, the timer (e.g., the timer 115 of FIG. 2) may transmit to the washing machine 1 a cumulative operation time, which is time during which the heater 44 operates during a drying cycle. The washing machine 1 may terminate a drying cycle in response to the cumulative operation time of the heater 44 exceeding a preset target operation time.

[0114] According to an embodiment, the target operation time may be shorter than an initially preset time for which a drying cycle is performed. Therefore, the washing machine 1 may terminate the drying cycle at a point earlier than a preset drying cycle required time.

[0115] According to an embodiment, as the washing machine 1 determines a point to terminate a drying cycle based on the cumulative operation time of the heater 44, a termination point of a drying cycle may be determined without having a separate sensor. Further, the washing machine 1 may minimize power consumption independently of factors affecting a drying cycle (e.g., amount of moisture included in laundry, temperature of cold water supplied into the condensation duct 43).

[0116] FIG. 4 is an operation flowchart for the washing machine 1 to control a drying cycle according to an embodiment.

[0117] At least some operations of FIG. 4 may correspond to operations illustrated in FIG. 3. Therefore, differences are mainly described.

[0118] According to an embodiment, the washing machine 1 may sense a weight of a drying object, i.e., a first weight, in operation 410. Operation 410 may correspond to all or some of operation 310.

[0119] According to an embodiment, the washing machine 1 may determine a target operation time of the heater 44 based on the first weight in operation 420. Operation 420 may correspond to all or some of operation 320.

[0120] According to an embodiment, the washing machine 1 may operate the heater 44 so that a temperature of dry air satisfies a threshold range in operation 430. Operation 430 may correspond to all or some of operation 330.

[0121] According to an embodiment, the washing machine 1 may determine whether a cumulative operation time of the heater 44 exceeds the target operation time in operation 440. At least a portion of operation 440 may correspond to all or some of operation 340.

[0122] In response to the cumulative operation time of the heater 44 exceeding the target operation time, the washing machine 1 may determine whether a drive rate of the heater 44 is less than a threshold level in operation 450. Here, a drive rate of the heater 44 may be defined based on a unit operation time and a unit idle time included in a unit operation cycle. The drive rate may be defined as the unit operation time relative to the unit operation cycle. In other words, the drive rate may be defined as a value obtained by dividing the unit operation time by the unit operation cycle. However, not limited thereto, the drive rate may be defined in various ways. For example, the drive rate may be defined as a value obtained by dividing the unit operation time by the unit idle time. Hereinafter, this document will describe by defining the drive rate as a value obtained by dividing the unit operation time by the unit operation cycle.

[0123] According to an embodiment, the drive rate may include at least multiple drive rates corresponding to unit operation cycles. The drive rate may include, e.g., a first drive rate, a second drive rate, ..., a kth drive rate, ..., an nth drive rate. Here, n is a natural number of 2 or more.

[0124] For example, the first drive rate may be defined as a value obtained by dividing a first unit operation time by a first unit operation cycle.

[0125] For example, the second drive rate may be defined as a value obtained by dividing a second unit operation time by a second unit operation cycle.

[0126] For example, the kth drive rate may be defined as a value obtained by dividing a kth unit operation time by a kth unit operation cycle.

[0127] For example, the nth drive rate may be defined as a value obtained by dividing an nth unit operation time by an nth unit operation cycle.

[0128] For example, if a kth unit operation time included in a kth unit operation cycle is 80 seconds and a kth unit idle time included in the kth unit operation cycle is 60 seconds, the kth drive rate may be derived as about 0.57. For example, if the drive rate is defined as a value obtained by dividing the unit operation time by the unit idle time, the kth drive rate may be derived as about 1.33.

[0129] According to an embodiment, as a drying cycle is performed, the drive rate may decrease. In other words, as a drying cycle is performed, time (unit operation time) for which the washing machine 1 operates the heater 44 to heat dry air to a preset temperature (e.g., first threshold temperature) may decrease. Further, time (unit idle time) during which the washing machine 1 stops operating the heater 44 while dry air heated to the first threshold temperature cools to a second threshold temperature may increase or remain constant. Accordingly, as a drying cycle is performed, a ratio of unit operation time included in a unit operation cycle may decrease, causing the drive rate to decrease.

[0130] According to an embodiment, the washing machine 1 may store a drive rate of the heater 44 as a drying cycle is performed in the memory (e.g., the memory 113 of FIG. 2). The washing machine 1 may determine whether a drive rate of the heater 44 has reached below a preset threshold level. The preset threshold level may be, e.g., 0.5. In other words, the washing machine 1 may determine whether there was a unit operation cycle in which a unit operation time was smaller than a unit idle time during a drying cycle.

[0131] If there is no unit operation cycle in which a drive rate of the heater 44 reached below the threshold level, the washing machine 1 may perform an additional drying cycle in operation 460. If a drive rate of the heater 44 has not reached below the threshold level, the washing machine 1 may determine that a drying cycle should be additionally performed on the drying object. Therefore, even in case that the target operation time is exceeded, the washing machine 1 may perform a drying cycle for a preset target drying time and then terminate the drying cycle.

[0132] According to an embodiment, because the washing machine 1 determines a point to terminate a drying cycle based on a drive rate of the heater 44, a drying cycle may be additionally performed to remove moisture included in the drying object so that a target degree of drying for the drying object may be reached.

[0133] FIG. 5 is an operation flowchart for the washing machine 1 to control a drying cycle according to an embodiment.

[0134] At least some operations of FIG. 5 may correspond to operations illustrated in FIG. 3 or 4. Therefore, differences are mainly described.

[0135] According to an embodiment, the washing machine 1 may sense a weight of a drying object, i.e., a first weight, in operation 510. Operation 510 may correspond to at least a portion of operation 310 or operation 410.

[0136] According to an embodiment, the washing machine 1 may determine a target operation time of the heater 44 based on the first weight in operation 520. Operation 520 may correspond to at least a portion of operation 320 or operation 420.

[0137] According to an embodiment, the washing machine 1 may operate the heater 44 so that a temperature of dry air satisfies a threshold range in operation 530. Operation 530 may correspond to at least a portion of operation 330 or operation 430.

[0138] According to an embodiment, the washing machine 1 may determine whether a cumulative operation time of the heater 44 exceeds the target operation time in operation 540. Operation 540 may correspond to at least a portion of operation 340 or operation 440.

[0139] In case that the cumulative operation time of the heater 44 exceeds the target operation time, the washing machine 1 may determine whether there is a unit operation cycle in which a drive rate of the heater 44 reached below a threshold level in operation 550. Operation 550 may correspond to at least a portion of operation 450.

[0140] If there is a unit operation cycle in which a drive rate of the heater 44 reached below the threshold level, the washing machine 1 may sense a weight of a drying object stored in the drum 12 in operation 560. The weight of the drying object may be defined as a "second weight."

[0141] According to an embodiment, the second weight may be the same as or different from the first weight. For example, the second weight, which is a weight of the drying object after a drying cycle has been performed, may be smaller compared to the first weight.

[0142] According to an embodiment, the washing machine 1 may determine whether a degree of drying of the drying object satisfies a threshold level in operation 570. The degree of drying of the drying object may be determined based on a weight of wet laundry before a drying cycle is performed (i.e., after a spinning cycle is performed) and a weight of dried laundry after a drying cycle is performed.

[0143] According to an embodiment, the degree of drying may be defined as a change value of a weight of laundry relative to the first weight. In other words, degree of drying [%] = (first weight - second weight) / (first weight) * 100[%]. For example, if a weight of wet laundry after a spinning cycle ends (first weight) is 10kg and a weight of laundry after a drying cycle is performed (second weight) is 9.9kg, the degree of drying may be derived as (10-9.9) / 10*100=1%.

[0144] According to an embodiment, the washing machine 1 may determine a termination point of a drying cycle based on a degree of drying of a drying object. Accordingly, the washing machine 1 may determine a termination point of a drying cycle to achieve a target degree of drying for a drying object. For example, the target degree of drying may be set to 0.2 to 0.3.

[0145] In case that a degree of drying of a drying object reaches below a threshold level, the washing machine 1 may terminate a drying cycle. For example, the washing machine 1 may terminate a drying cycle at a point earlier than when a target drying time elapses.

[0146] According to an embodiment, if there is no unit operation cycle in which a drive rate of the heater 44 reached below a threshold level, or if a degree of drying of a drying object does not satisfy a threshold level, the washing machine 1 may additionally perform a drying cycle in operation 580. Operation 580 may correspond to at least a portion of operation 460. The washing machine 1 may perform a drying cycle for a preset target drying time and then terminate the drying cycle.

[0147] According to an embodiment, the washing machine 1 may minimize power required to perform a drying cycle independently of factors affecting the drying cycle while simultaneously optimizing a degree of drying of a drying object.

[0148] FIG. 6 illustrates a graph of current of a switching signal for operating heater 44 (e.g., the heater 44 of FIG. 1) during a drying cycle and a graph illustrating temperature change of dry air according to an embodiment.

[0149] Referring to FIG. 6, while a drying cycle is performed, washing machine (e.g., the washing machine 1 of FIG. 1) may operate or stop operating the heater 44 so that a temperature of dry air satisfies a preset threshold range. Accordingly, the controller (e.g., the controller 110 of FIG. 2) may repeatedly output a control signal for operating the heater 44 in response to time elapse during a drying cycle. The control signal may be, e.g., a pulse-type signal having a predetermined current. The predetermined current may be, e.g., I h . Graph (a) may be understood as illustrating a pulse-type control signal that the controller 110 outputs to the heater 44. Graph (b) may be understood as illustrating a temperature of dry air measured by the temperature sensor (e.g., the temperature sensor 123 of FIG. 2) over time. However, graph (b) is not limited to a temperature of dry air and may also be a temperature inside the drum (e.g., the drum 12 of FIG. 1) measured by the temperature sensor 123.

[0150] According to an embodiment, the washing machine 1 may operate or stop operating the heater 44 based on a temperature of dry air obtained from the temperature sensor 123. For example, the washing machine 1 may operate the heater 44 so that a temperature of dry air satisfies a preset threshold range. The threshold range may be set to, e.g., a first threshold temperature T1 to a second threshold temperature T2.

[0151] According to an embodiment, in case that a temperature of dry air becomes lower than the first threshold temperature T1, the washing machine 1 may output a control signal for operating the heater 44. Accordingly, the heater 44 may heat the dry air. In case that the temperature of the dry air reaches the second threshold temperature T2, the washing machine 1 may stop outputting the control signal. As the operation of the heater 44 stops, the dry air may be cooled.

[0152] According to an embodiment, due to operation of the heater 44, the dry air may be gradually heated. The temperature of the dry air may increase in the form of a logarithmic function corresponding to an operation time of the dry air, for example. However, not limited thereto, the temperature of the dry air may increase in the form of an exponential function corresponding to an operation time of the dry air, or may increase in the form of a linear function with a constant slope corresponding to an operation time of the dry air.

[0153] According to an embodiment, as the operation of the heater 44 stops, the dry air may be gradually cooled. The temperature of the dry air may decrease in the form of a logarithmic function corresponding to an operation time of the dry air, for example. However, not limited thereto, the temperature of the dry air may decrease in the form of an exponential function corresponding to an operation time of the dry air, or may decrease in the form of a linear function with a constant slope corresponding to an operation time of the dry air.

[0154] According to an embodiment, at time t1, the washing machine 1 may output a control signal for operating the heater 44 in response to a temperature of the dry air reaching the first threshold temperature T1. The washing machine 1 may output the control signal until time t1' when the temperature of the dry air reaches the second threshold temperature T2. An interval from the time t1 to the time t1' may be defined as a first unit operation time d#1. An interval from the time t1' to the time t2 may be defined as a first unit idle time d#1'. An interval from the time t1 to the time t2 may be defined as a first unit operation cycle p#1. The washing machine 1 may derive a first drive rate, which is a ratio of the first unit operation time d#1 to the first unit operation cycle p#1.

[0155] According to an embodiment, at time t2, the washing machine 1 may output a control signal for operating the heater 44 in response to a temperature of the dry air reaching the first threshold temperature T1. The washing machine 1 may output the control signal until time t2' when the temperature of the dry air reaches the second threshold temperature T2. An interval from the time t2 to the time t2' may be defined as a second unit operation time d#2. An interval from the time t2' to the time t3 may be defined as a second unit idle time d#2'. An interval from the time t2 to the time t3 may be defined as a second unit operation cycle p#2. The washing machine 1 may derive a second drive rate, which is a ratio of the second unit operation time d#2 to the second unit operation cycle p#2.

[0156] According to an embodiment, at time t3, the washing machine 1 may output a control signal for operating the heater 44 in response to a temperature of the dry air reaching the first threshold temperature T1. The washing machine 1 may output the control signal until time t3' when the temperature of the dry air reaches the second threshold temperature T2. An interval from the time t3 to the time t3' may be defined as a third unit operation time d#3. An interval from the time t3' to the time t4 may be defined as a third unit idle time d#3'. An interval from the time t3 to the time t4 may be defined as a third unit operation cycle p#3. The washing machine 1 may derive a third drive rate, which is a ratio of the third unit operation time d#3 to the third unit operation cycle p#3.

[0157] According to an embodiment, at time t(n-2), the washing machine 1 may output a control signal for operating the heater 44 in response to a temperature of the dry air reaching the first threshold temperature T1. The washing machine 1 may output the control signal until time t(n-2)' when the temperature of the dry air reaches the second threshold temperature T2. An interval from the time t(n-2) to the time t(n-2)' may be defined as a n-2th unit operation time d#(n-2). An interval from the time t(n-2)' to the time t(n-1) may be defined as a n-2th unit idle time d#(n-2'). An interval from the time t(n-2) to the time t(n-1) may be defined as a n-2th unit operation cycle p#(n-2). The washing machine 1 may derive a n-2th drive rate, which is a ratio of the n-2th unit operation time d#(n-2) to the n-2th unit operation cycle p#(n-2).

[0158] According to an embodiment, at time t(n-1), the washing machine 1 may output a control signal for operating the heater 44 in response to a temperature of the dry air reaching the first threshold temperature T1. The washing machine 1 may output the control signal until time t(n-1)' when the temperature of the dry air reaches the second threshold temperature T2. An interval from the time t(n-1) to the time t(n-1)' may be defined as a n-1th unit operation time d#(n-1). An interval from the time t(n-1)' to the time tn may be defined as a n-1th unit idle time d#(n-1'). An interval from the time t(n-1) to the time tn may be defined as a n-1th unit operation cycle p#(n-1). The washing machine 1 may derive a n-1th drive rate, which is a ratio of the n-1th unit operation time d#(n-1) to the n-1th unit operation cycle p#(n-1).

[0159] According to an embodiment, at time tn, the washing machine 1 may output a control signal for operating the heater 44 in response to a temperature of the dry air reaching the first threshold temperature T1. The washing machine 1 may output the control signal until time tn' when the temperature of the dry air reaches the second threshold temperature T2. An interval from the time tn to the time tn' may be defined as an nth unit operation time d#n. An interval from the time tn' to the time tf may be defined as an nth unit idle time d#n'. An interval from the time tn to the time tf may be defined as an nth unit operation cycle p#n. The washing machine 1 may derive an nth drive rate, which is a ratio of the nth unit operation time d#n to the nth unit operation cycle p#n.

[0160] According to an embodiment, the washing machine 1 may derive a drive rate based on consecutive unit idle times and unit operation times.

[0161] For example, the washing machine 1 may derive a drive rate according to a ratio of the second unit operation time d#2 to a combined time of the first unit idle time d#1' and the second unit operation time d#2.

[0162] For example, the washing machine 1 may derive a drive rate according to a ratio of the third unit operation time d#3 to a combined time of the second unit idle time d#2' and the third unit operation time d#3.

[0163] For example, the washing machine 1 may derive a drive rate according to a ratio of the n-1th unit operation time d#(n-1) to a combined time of the n-2th unit idle time d#(n-2') and the n-1th unit operation time d#(n-1).

[0164] For example, the washing machine 1 may derive a drive rate according to a ratio of the nth unit operation time d#n to a combined time of the n-1th unit idle time d#(n-1') and the nth unit operation time d#n.

[0165] According to an embodiment, at time tf, the washing machine 1 may terminate a drying cycle.

[0166] According to an embodiment, as time elapses during a drying cycle, time for heating a temperature of dry air from the first threshold temperature T1 to the second threshold temperature T2 may decrease. Further, as time elapses during a drying cycle, time for a temperature of dry air to cool from the second threshold temperature T2 to the first threshold temperature T1 may remain constant or increase. Accordingly, as time elapses during a drying cycle, a unit operation rate may decrease.

[0167] According to an embodiment, the washing machine 1 may determine a target operation time based on the first weight, which is a weight of a drying object. The washing machine 1 may terminate a drying cycle in case that a cumulative operation time, which is a sum of at least multiple unit operation times, reaches the target operation time.

[0168] According to an embodiment, in case that the cumulative operation time reaches the target operation time, the washing machine 1 may determine whether there was a unit operation cycle during a drying cycle in which a drive rate of the heater 44 reached below a preset threshold level. The preset threshold level may be, e.g., 0.5. If there is a unit operation cycle in which a drive rate of the heater 44 reached below the threshold level, the washing machine 1 may terminate a drying cycle. If there is no unit operation cycle in which a drive rate of the heater 44 reached below the threshold level, the washing machine 1 may additionally perform a drying cycle for a preset time and then terminate the drying cycle.

[0169] According to an embodiment, in case that the cumulative operation time reaches the target operation time, the washing machine 1 may sense a third weight, which is a weight of a drying object. The washing machine 1 may derive a degree of drying of the drying object by calculating an amount of change of the third weight relative to the first weight. If a degree of drying of the drying object satisfies a threshold level, the washing machine 1 may terminate a drying cycle. If a degree of drying of the drying object does not satisfy the threshold level, the washing machine 1 may additionally perform a drying cycle for a preset time and then terminate the drying cycle.

[0170] A washing machine (e.g., the washing machine 1 of FIG. 1 or the washing machine 100 of FIG. 2) according to an embodiment of the disclosure may include a heater 44 heating dry air to be supplied into an interior of a drum 12, a temperature sensor 123 sensing a temperature of the dry air, and a controller 110 controlling operation of the heater 44 in response to activation of a drying function. The controller 110 may control (330) whether to operate the heater 44 so that the temperature of the dry air is maintained constantly with respect to a target control temperature in case that a drying cycle is initiated by the activation of the drying function, and may terminate (340) the drying cycle in response to arrival of a drying termination time within a preset reference operation section for initiation or termination of the drying cycle. The drying termination time may be identified by a weight of a drying object obtained in response to the activation of the drying function.

[0171] In the washing machine (1, 100) according to an embodiment of the disclosure, the controller 110 may determine that the drying termination time has arrived in case that a cumulative operation time of the heater 44 measured after the drying cycle is initiated reaches a threshold cumulative operation time. The threshold cumulative operation time may be set by the obtained weight of the drying object.

[0172] In the washing machine (1, 100) according to an embodiment of the disclosure, the controller 110 may determine (450) whether to resume the drying cycle based on a drive rate of the heater 44 upon terminating (340) the drying cycle.

[0173] In the washing machine (1, 100) according to an embodiment of the disclosure, the controller 110 may determine (460) to resume the drying cycle in case that the drive rate of the heater 44 exceeds a predetermined threshold.

[0174] In the washing machine (1, 100) according to an embodiment of the disclosure, the controller 110 may obtain the drive rate according to a ratio of a unit operation section of the heater 44 to a unit idle section of the heater 44. The unit idle section is continuous with the unit operation section, the unit operation section is an elapsed time between a start time and an end time indicating a unit section in which the heater 44 operates, and the unit idle section may be one of an elapsed time between the end time and a start time indicating a unit section in which the heater 44 does not operate, or an elapsed time between the end time and the drying termination time.

[0175] In the washing machine (1, 100) according to an embodiment of the disclosure, the controller 110 may obtain the drive rate according to a ratio of a unit operation section of the heater 44 to a unit idle section of the heater 44. The unit operation section is continuous with the unit idle section, the unit idle section is an elapsed time between an end time and a start time indicating a unit section in which the heater 44 does not operate, and the unit operation time may be an elapsed time between the start time and an end time indicating a unit section in which the heater 44 operates.

[0176] In the washing machine (1, 100) according to an embodiment of the disclosure, the controller 110 may terminate the resumed drying cycle at an end time of the preset reference operation section.

[0177] In the washing machine (1, 100) according to an embodiment of the disclosure, the controller 110 may terminate the resumed drying cycle in case that the drive rate is less than the predetermined threshold.

[0178] In the washing machine (1, 100) according to an embodiment of the disclosure, the controller 110 may measure the weight of the drying object in case that a weight sensing cycle is initiated by the activation of the drying function, and may initiate the drying cycle in case that the weight sensing cycle is completed.

[0179] In the washing machine (1, 100) according to an embodiment of the disclosure, the controller 110 may control the heater 44 to operate in case that the temperature of the dry air is substantially lower than the target control temperature, and may control operation of the heater 44 to stop in case that the temperature of the dry air is substantially higher than the target control temperature.

[0180] A control method of the washing machine (1, 100) according to an embodiment of the disclosure may include an operation (330) of controlling whether to operate the heater 44 so that the temperature of the dry air is maintained constantly with respect to a target control temperature in case that a drying cycle is initiated by the activation of the drying function, and an operation (340) of terminating the drying cycle in response to arrival of a drying termination time within a preset reference operation section for initiation or termination of the drying cycle. The drying termination time may be identified (320) by a weight of a drying object obtained in response to the activation of the drying function.

[0181] The control method of the washing machine (1, 100) according to an embodiment of the disclosure may include an operation (340) of determining that the drying termination time has arrived in case that a cumulative operation time of the heater 44 measured after the drying cycle is initiated reaches a threshold cumulative operation time. The threshold cumulative operation time may be set by the obtained weight of the drying object.

[0182] The control method of the washing machine (1, 100) according to an embodiment of the disclosure may include an operation of determining (450) whether to resume the drying cycle based on a drive rate of the heater 44 upon terminating (340, 440) the drying cycle.

[0183] The control method of the washing machine (1, 100) according to an embodiment of the disclosure may include an operation (460) of determining to resume the drying cycle in case that the drive rate of the heater 44 exceeds a predetermined threshold.

[0184] The control method of the washing machine (1, 100) according to an embodiment of the disclosure may include an operation of obtaining the drive rate according to a ratio of a unit operation section of the heater 44 to a unit idle section of the heater 44. The unit idle section is continuous with the unit operation section, the unit operation section is an elapsed time between a start time and an end time indicating a unit section in which the heater 44 operates, and the unit idle section may be one of an elapsed time between the end time and a start time indicating a unit section in which the heater 44 does not operate, or an elapsed time between the end time and the drying termination time.

[0185] The control method of the washing machine (1, 100) according to an embodiment of the disclosure may include an operation of obtaining the drive rate according to a ratio of a unit operation section of the heater 44 to a unit idle section of the heater 44. The unit operation section is continuous with the unit idle section, the unit idle section is an elapsed time between an end time and a start time indicating a unit section in which the heater 44 does not operate, and the unit operation time may be an elapsed time between the start time and an end time indicating a unit section in which the heater 44 operates.

[0186] The control method of the washing machine (1, 100) according to an embodiment of the disclosure may include an operation of terminating the resumed drying cycle at an end time of the preset reference operation section.

[0187] The control method of the washing machine (1, 100) according to an embodiment of the disclosure may include an operation of terminating the resumed drying cycle in case that the drive rate is less than the predetermined threshold.

[0188] The control method of the washing machine (1, 100) according to an embodiment of the disclosure may include an operation of controlling the heater 44 to operate in case that the temperature of the dry air is substantially lower than the target control temperature and an operation of controlling operation of the heater 44 to stop in case that the temperature of the dry air is substantially higher than the target control temperature.

[0189] The terms as used herein are provided merely to describe some embodiments thereof, but are not intended to limit the disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, each of such phrases as "A or B," "at least one of A and B," "at least one of A or B," "A, B, or C," "at least one of A, B, and C," and "at least one of A, B, or C," may include all possible combinations of the items enumerated together in a corresponding one of the phrases. As used herein, the term 'and / or' should be understood as encompassing any and all possible combinations by one or more of the enumerated items. As used herein, the terms "include," "have," and "comprise" are used merely to designate the presence of the feature, component, part, or a combination thereof described herein, but use of the term does not exclude the likelihood of presence or adding one or more other features, components, parts, or combinations thereof. As used herein, the terms "first" and "second" may modify various components regardless of importance and / or order and are used to distinguish a component from another without limiting the components.

[0190] As used herein, the terms "configured to" may be interchangeably used with the terms "suitable for," "having the capacity to," "designed to," "adapted to," "made to," or "capable of" depending on circumstances. The term "configured to" does not essentially mean "specifically designed in hardware to." Rather, the term "configured to" may mean that a device can perform an operation together with another device or parts. For example, a 'device configured (or set) to perform A, B, and C' may be a dedicated device to perform the corresponding operation or may mean a general-purpose device capable of various operations including the corresponding operation.

[0191] Meanwhile, the terms "upper side", "lower side", and "front and rear directions" used in the disclosure are defined with respect to the drawings, and the shape and position of each component are not limited by these terms.

[0192] In the disclosure, the above-described description has been made mainly of specific embodiments, but the disclosure is not limited to such specific embodiments, but should rather be appreciated as covering all various modifications, equivalents, and / or substitutes of various embodiments.

Examples

Embodiment Construction

[0012]Hereinafter, embodiments of the disclosure are described in detail with reference to the drawings so that those skilled in the art to which the disclosure pertains may easily practice the disclosure. However, the disclosure may be implemented in other various forms and is not limited to the embodiments set forth herein. The same or similar reference denotations may be used to refer to the same or similar elements throughout the specification and the drawings. Further, for clarity and brevity, no description is made of well-known functions and configurations in the drawings and relevant descriptions.

[0013]Further, the terms to be described below is defined as follows. Laundry introduced into washing machine 1 and disposed inside drum 12 before washing, rinsing, and spinning cycles are performed is referred to as "washing object." Laundry before washing machine 1 performs a drying cycle to dry the washing object is referred to as "drying object." The drying object that has been ...

[Technical Field]

[0001] Various embodiments of the disclosure relate to a washing machine equipped with a drying device, and more particularly to a washing machine and a method thereof that adaptively performs a drying cycle based on a weight of a drying object.[Background Art]

[0002] A drying device is a device that dries clothes by rotating a drum including wet clothes (drying objects) at low speed while supplying hot air heated by a heater into the drum. Recently, a washing machine with a drying device capable of both drying and washing may perform a drying cycle alone or perform a drying cycle after completion of spinning in connection with a washing cycle.

[0003] A washing machine may determine when a drying cycle is performed and terminated according to a type of drying object or a type of washing cycle (washing course). Further, a washing machine may adjust an output of a drying device while a drying cycle is being performed. A washing machine may obtain information for performing a drying cycle and determining a termination point.

[0004] Meanwhile, in case that a drying object is not sufficiently dried, user experience may deteriorate due to insufficient drying. In case that a drying object is excessively dried, damage to the drying object may occur, an interior of the washing machine may overheat, and unnecessary power consumption may occur.[DISCLOSURE OF INVENTION] [Technical Problem]

[0005] Various embodiments of the disclosure may propose a washing machine and a control method that provides optimal drying performance and drying efficiency based on a weight of a drying object during a drying cycle.[Solution to Problems]

[0006] A washing machine according to an embodiment of the disclosure may include a heater heating dry air to be supplied into an interior of a drum, a temperature sensor for sensing a temperature of the dry air, and a controller controlling operation of the heater in response to activation of a drying function. The controller may control whether to operate the heater to maintain constant the temperature of the dry air with respect to a target control temperature in case that a drying cycle is initiated by the activation of the drying function, and terminate the drying cycle in response to arrival of a drying termination time within a preset reference operation section for initiation or termination of the drying cycle. The drying termination time may be identified by a weight of a drying object obtained in response to the activation of the drying function.

[0007] A method for controlling operation of a heater in response to activation of a drying function in a washing machine according to an embodiment of the disclosure may include controlling whether to operate the heater to maintain constant a temperature of dry air with respect to a target control temperature in case that a drying cycle is initiated by the activation of the drying function, and terminating the drying cycle in response to arrival of a drying termination time within a preset reference operation section for initiation or termination of the drying cycle. The drying termination time may be identified by a weight of a drying object obtained in response to the activation of the drying function.[Advantageous Effects]

[0008] A washing machine according to an embodiment of the disclosure may minimize power required for performing a drying cycle.

[0009] A washing machine according to an embodiment of the disclosure may provide drying performance independently of conditions required for drying components or target drying objects.[BRIEF DESCRIPTION OF DRAWINGS]

[0010] FIG. 1 is a cross-sectional view illustrating a washing machine according to an embodiment of the disclosure; FIG. 2 is a block diagram illustrating a washing machine according to an embodiment of the disclosure; FIG. 3 is an operation flowchart for a washing machine to control a drying cycle according to an embodiment of the disclosure; FIG. 4 is an operation flowchart for a washing machine to control a drying cycle according to an embodiment of the disclosure; FIG. 5 is an operation flowchart for a washing machine to control a drying cycle according to an embodiment of the disclosure; and FIG. 6 is a graph illustrating a current of a switching signal for operating a heater during a drying cycle and a graph illustrating temperature change of dry air according to an embodiment of the disclosure.

[0011] In relation to the description of the drawings, the same or similar reference numerals may be used for the same or similar components.[MODE FOR THE INVENTION]

[0012] Hereinafter, embodiments of the disclosure are described in detail with reference to the drawings so that those skilled in the art to which the disclosure pertains may easily practice the disclosure. However, the disclosure may be implemented in other various forms and is not limited to the embodiments set forth herein. The same or similar reference denotations may be used to refer to the same or similar elements throughout the specification and the drawings. Further, for clarity and brevity, no description is made of well-known functions and configurations in the drawings and relevant descriptions.

[0013] Further, the terms to be described below is defined as follows. Laundry introduced into washing machine 1 and disposed inside drum 12 before washing, rinsing, and spinning cycles are performed is referred to as "washing object." Laundry before washing machine 1 performs a drying cycle to dry the washing object is referred to as "drying object." The drying object that has been dried after washing machine 1 completes the drying cycle is referred to as "dried laundry." The mentioned terms may be used interchangeably as necessary, but in cases of a transition state between at least two states among "washing object," "drying object," and "dried laundry," or cases that do not correspond to any of the three states, they may be collectively referred to as "laundry."

[0014] FIG. 1 is a cross-sectional view illustrating a washing machine 1 according to an embodiment. In other words, FIG. 1 may be understood as a cross-sectional view cut in one direction to show a configuration of a washing machine equipped with a drying device 40.

[0015] Referring to FIG. 1, the washing machine 1 may include a drying device 40 for drying a drying object. Hereinafter, the washing machine 1 according to the disclosure is described focusing on a front-load type washing machine but, without limitations thereto, may be applied to a washing machine equipped with a pulsator and a drying device 40. In other words, the washing machine 1 may include a front-load type washing machine or a top-load type washing machine.

[0016] According to an embodiment, the washing machine 1 may include a drum-type tub 11 provided inside a main body 10 for storing water (e.g., washing water and rinsing water), and a drum 12 rotatably provided inside the tub 11 and having a plurality of drain holes formed therein.

[0017] According to an embodiment, a driving motor 13 that rotates the drum 12 and / or a pulsator (e.g., the pulsator 210 of FIG. 3) in forward or reverse directions to perform washing, rinsing, and spinning operations may be provided at a lower portion of the tub 11. The driving motor 13 may generate torque for rotating the drum 12 and / or the pulsator 210. One surface (e.g., an inner surface) of the drum may be connected to a rotation shaft of the driving motor 13.

[0018] According to an embodiment, the pulsator 210 may be rotatably provided on an inner surface of the drum 12. The pulsator 210 may rotate independently of the drum 12. In other words, the pulsator 210 may rotate in the same direction as the drum 12 or in a different direction. The pulsator 210 may rotate at the same speed as the drum 12 or at a different speed.

[0019] According to an embodiment, one or more driving motors 13 may be provided.

[0020] For example, in case that one driving motor 13 is provided, the driving motor 13 may be connected to the drum 12, the pulsator 210, and a blowing fan 41. The driving motor 13 may drive the drum 12, the pulsator 210, and the blowing fan 41 together.

[0021] For example, in case that multiple driving motors 13 are provided, the driving motors 13 may be connected to the drum 12, the pulsator 210, and the blowing fan 41, respectively. Each driving motor 13 may drive the connected drum 12, pulsator 210, and blowing fan 41.

[0022] According to an embodiment, a washing water heater 16 that heats water (e.g., washing water) to be supplied into the tub 11 corresponding to a temperature of washing water to be used in a washing cycle may be provided inside a lower portion of the tub 11.

[0023] According to an embodiment, an opening 14 may be formed at the front of the tub 11 and the drum 12 so that a user may remove laundry from the front of the main body 10. A door 15 for opening and closing the opening 14 may be provided at the front of the main body 10. The door 15 may be hingedly coupled to one side of the front of the main body 10. The door 15 may open and close the opening 14 by rotating around the one side of the front of the main body 10 as an axis.

[0024] According to an embodiment, a detergent supply device 18 for supplying detergent and a water supply portion 20 for supplying washing water and rinsing water may be provided at an upper portion of the tub 11.

[0025] For example, the detergent supply device 18 may be divided into one space or multiple spaces inside. The detergent supply device 18 may be provided on the front of the main body 10 for easy introduction of detergent and rinse aid. Detergent or rinse aid may be stored in the divided multiple spaces.

[0026] According to an embodiment, the water supply portion 20 may include a water supply pipe 22 that supplies water and a water supply valve 24 installed in the water supply pipe 22 to control water supply of the water supply pipe 22. The water supply pipe 22 may be connected to the detergent supply device 18 so that water supplied from outside may be supplied toward the detergent supply device 18. For the detergent in the detergent supply device 18 to be supplied to the tub 11 in a dissolved state in water, a separate connection pipe 26 may be provided between the detergent supply device 18 and the tub 11 so that water passing through the detergent supply device 18 may be supplied to the tub 11 together with detergent, and a water supply nozzle 28 may be provided at an outlet of the connection pipe 26.

[0027] According to an embodiment, the washing machine 1 may include a drainage portion 30 for draining water inside the tub 11. The drainage portion 30 may include a drainage pipe 31 connected to a lower portion of the tub 11 to guide water in the tub 11 to the outside, and a drainage pump 32 installed in the drainage pipe 31.

[0028] According to an embodiment, the washing machine 1 may include a drying device 40. The drying device 40 may include a blowing fan 41 installed at an upper portion of the tub 11, a drying duct 42 connecting between a discharge port 41b of the blowing fan 41 and an air inlet 45 formed above the opening 14 of the tub 11, a condensation duct 43 mounted at the rear of the tub 11 to connect between an air outlet 46 formed at a lower rear portion of the tub 11 and an intake port 41a of the blowing fan 41, and a heater 44 installed inside the drying duct 42 to generate high-temperature air supplied into the drum 12.

[0029] According to an embodiment, a spray nozzle 47 that sprays condensation water (cold water) into the condensation duct 43 may be provided at an upper inner portion of the condensation duct 43 so that moisture may be condensed and removed as high-temperature and high-humidity air generated through drying of the drying object passes through the condensation duct 43. The spray nozzle 47 may be connected to the water supply portion 20 through a condensation water supply pipe 48 and a condensation water valve 49 to supply condensation water.

[0030] According to an embodiment, a spray nozzle 47 that sprays condensation water (cold water) into the condensation duct 43 may be provided at an upper inner portion of the condensation duct 43 so that moisture may be condensed and removed as high-temperature and high-humidity air generated through drying of the drying object passes through the condensation duct 43. An outlet 43a for discharging condensed water may be formed at a lower side of the condensation duct 43. Condensation water discharged through the outlet 43a may flow into a drainage pipe 31 of the drainage portion 30.

[0031] An example of operation of the washing machine 1 equipped with the drying device 40 is as follows.

[0032] According to an embodiment, the washing machine 1 may perform at least one of a washing cycle, a rinsing cycle, a spinning cycle, and a drying cycle. By user selection, the washing machine 1 may perform only one of a washing cycle, a rinsing cycle, a spinning cycle, and a drying cycle, or may perform a combination of at least two of a washing cycle, a rinsing cycle, a spinning cycle, and a drying cycle. The example to be described below may be understood as a case where the washing machine 1 performs all of a washing cycle, a rinsing cycle, a spinning cycle, and a drying cycle in sequence.

[0033] As a washing cycle begins, in case that the water supply valve 24 of the water supply device 20 opens, water (washing water) may be supplied to the tub 11 after passing through the water supply pipe 22 and the detergent supply device 18. In case that water supply is completed, the washing water heater 16 is operated to heat the washing water filled in the tub 11 to a temperature required for washing, and then the drum 12 rotates forward or backward by driving the driving motor 13, and a washing cycle may be performed by friction with the drum 12 and decomposition force of detergent.

[0034] As the washing cycle ends, a rinsing cycle may begin. The washing machine 1 may repeat spinning and water supply in the rinsing cycle. As the rinsing cycle ends, a spinning cycle may be performed. The washing machine 1 may operate the driving motor 13 at high speed in the spinning cycle to rotate the drum 12 at high speed.

[0035] As the spinning cycle ends, a drying cycle may begin. The washing machine 1 may operate the driving motor 13 at low speed to rotate the drum 12 at low speed. The washing machine 1 may operate the heater 44 and the blowing fan 41 so that air inside the drum 12 is drawn toward the blowing fan 41 through the condensation duct 43, and then circulated to be discharged back into the drum 12 through the drying duct 42. Accordingly, air in the drying duct 42 is heated by the heater 44 and flows into the drum 12 in a high-temperature dry state, and the drying object inside the drum 12 is heated by the high-temperature dry air (hot air), causing moisture included in the drying object to evaporate and be dried. In this case, air in the drying duct 42 is heated by the heater 44 and flows into the drum 12 in a high-temperature dry state, and the drying object inside the drum 12 is heated by the high-temperature dry air (hot air), causing moisture included in the drying object to evaporate and be dried. As the drying cycle progresses, the high-temperature dry air absorbs moisture from the drying object and changes to high-temperature humid air which is transferred to the condensation duct 43, and the high-temperature humid air transferred to the condensation duct 43 contacts condensation water (cold water) sprayed through the spray nozzle 47 to be condensed and changed to dry air, and the drying object may be dried by repeating the process of heating this dry air again in the heater 44 and flowing it into the drum 12.

[0036] FIG. 2 is a block diagram illustrating a washing machine 100 (e.g., the washing machine 1 of FIG. 1) according to an embodiment. At least some components of FIG. 2 may correspond to components illustrated in FIG. 1.

[0037] Referring to FIG. 2, a user interface 121 may include a user input for obtaining an input for an operation command of the washing machine 100. The input portion may be implemented as buttons (not illustrated) provided on an upper front portion of the main body (e.g., the main body 10 of FIG. 1). The buttons may include touch-type buttons or dial-type buttons.

[0038] For example, the input portion may receive preset operation methods for washing, rinsing, spinning, or drying cycles from a user. The input portion may receive commands for the number of times or operation time for the cycles from a user.

[0039] According to an embodiment, the input portion may transmit received information to a controller 110.

[0040] According to an embodiment, the user interface 121 may include an output portion for visually or audibly outputting operation information. The output portion may be implemented as a display (not illustrated) provided on an upper front portion of the main body 10. The display may be implemented as a light emitting diode (LED), an organic light emitting diode (OLED), or a liquid crystal display (LCD).

[0041] According to an embodiment, the output portion may visually output information obtained by the input portion.

[0042] For example, the output portion may visually output remaining execution time for the cycles.

[0043] For example, the output portion may also include a speaker for audibly outputting operation information. The output portion may output guide voices announcing the start or end of the cycles through the speaker.

[0044] According to an embodiment, the controller 110 may transmit information or control signals to be output to the output portion.

[0045] According to an embodiment, the user interface 121 may be implemented as a touch screen panel that simultaneously performs input and output functions.

[0046] According to an embodiment, a temperature sensor 123 may sense a temperature of air or water. The temperature sensor 123 may include a thermistor. The temperature sensor 123 may transmit an electrical signal corresponding to an electrical resistance value that changes with temperature of the thermistor to the controller 110.

[0047] According to an embodiment, multiple temperature sensors 123 may be implemented and provided at positions where temperature is to be sensed.

[0048] For example, the temperature sensor 123 may sense a temperature of washing water (or rinsing water) supplied inside the drum (e.g., the drum 12 of FIG. 1) during a washing cycle (or rinsing cycle).

[0049] For example, the temperature sensor 123 may sense a temperature of dry air (hot air) supplied to the drum 12 during a drying cycle. The temperature sensor 123 may be provided on the drying duct (e.g., the drying duct 42 of FIG. 1) or on the air inlet (e.g., the air inlet 45 of FIG. 1).

[0050] For example, the temperature sensor 123 may sense a temperature of dry air (hot air) discharged from the drum 12 during a drying cycle. The temperature sensor 123 may be provided on the drying duct 42 or on the air outlet (e.g., the air outlet 46 of FIG. 1).

[0051] According to an embodiment, based on information about temperature sensed by the temperature sensor 123, the controller 110 may control operation of the heater 44. The controller 110 may operate or stop operating the heater 44 so that the temperature satisfies a preset range based on a temperature inside the drum 12 or of the dry air.

[0052] According to an embodiment, a current sensor 125 may sense current flowing through a driving motor 13 (e.g., the driving motor 13 of FIG. 1) and transmit the corresponding current signal to the controller 110. The controller 110 may sense a weight of a drying object (or washing object) or sense a degree of drying of the drying object (or washing object) based on a current signal obtained from the current sensor 125.

[0053] For example, the controller 110 may repeatedly turn on / off the driving motor 13 to rotate the drum 12 and / or the pulsator 210. A weight of laundry may be measured based on a back electromotive force value generated in case that the driving motor 13 is turned off.

[0054] For example, the controller 110 may transmit a signal to the driving unit 200 to rotate the drum 12 and / or the pulsator 210 at a target operating speed, and may measure a weight of laundry based on time required for the drum 12 and / or the pulsator 210 to reach the target operating speed.

[0055] For example, the controller 110 may also measure a load inside the drum 12 based on a sensing value obtained from the driving motor 13.

[0056] Without limitation to the above-described method, the washing machine 100 may measure a load inside the drum 12 through various other methods. For example, the washing machine 1 may also measure a weight of laundry from information obtained from a weight measurement sensor provided below the drum 12.

[0057] According to an embodiment, the controller 110 may control the overall operation of the washing machine 1. The controller 110 may transmit information necessary for operation of the washing machine 1 or output information about an operation state of the washing machine 1.

[0058] According to an embodiment, the controller 110 may include a processor 111 that generates control signals for controlling operation of the washing machine 1 and memory 113 for storing or saving programs or data for generating the control signals. Hereinafter, control signals generated from the controller 110 may be understood as control signals generated by the processor 111.

[0059] According to an embodiment, at least some of the processor 111, the memory 113, and a timer 115 may be configured independently of the controller 110 or may be implemented integrally.

[0060] According to an embodiment, the processor 111 and the memory 113 may be implemented as separate chips or as a single chip. For example, the processor 111 may be implemented as a single processor or at least multiple processors, and the memory 113 may be implemented as one or multiple (e.g., volatile memory or nonvolatile memory).

[0061] According to an embodiment, the memory 113 may store or save programs and data for controlling operation of the washing machine 1.

[0062] For example, the memory 113 may store a course of a drying cycle according to a course of a selected washing cycle. For example, according to a type of course of a drying cycle, a total time for the washing machine 100 to perform a drying cycle, that is, time or operating power for the washing machine 100 to operate the heater 44, the blowing fan 41, the drum 12 and / or the pulsator 210 to perform a drying cycle may be stored. Here, the total time for the washing machine 100 to perform a preset drying cycle may be referred to as "target drying time" or "reference operation section."

[0063] For example, a setting value for a target operation time of the heater 44 according to a weight of a drying object may be stored in the memory 113 as a database (DB). The database may be stored in the memory 113 as a table of target operation times corresponding to weights of drying objects.

[0064] For example, a range of set temperatures inside the drum 12 according to a type of drying cycle (e.g., course of drying cycle) may be stored in the memory 113.

[0065] For example, an operation time of an additional drying cycle according to occurrence of an event for performing an additional drying cycle may be stored in the memory 113.

[0066] According to an embodiment, the memory 113 may store a user input received through the input portion or store information about operation of the washing machine 1 (e.g., remaining time for each cycle of the washing machine).

[0067] According to an embodiment, the timer 115 may count an operation time of the washing machine 1. The timer 115 may be implemented in hardware and provided as a separate module, or implemented in software and provided integrally with the controller 110.

[0068] According to an embodiment, the timer 115 may count time for operations where the washing machine 1 performs washing, rinsing, spinning, or drying cycles.

[0069] According to an embodiment, the timer 115 may count time during which the heater 44 operates during a drying cycle. For example, in case that the heater 44 repeatedly operates and stops operating, the timer 115 may count only the time during which the heater 44 operates.

[0070] According to an embodiment, the controller 110 may determine whether time counted by the timer 115 exceeds a preset target operation time. For example, the controller 110 may determine whether time during which the heater 44 has operated exceeds a preset target operation time. In case that the preset target operation time is exceeded, the controller 110 may terminate the drying cycle.

[0071] According to an embodiment, the controller 110 may control the overall operation of the washing machine 1. For example, the controller 110 may control to perform washing, rinsing, spinning, or drying cycles.

[0072] For example, the controller 110 may heat dry air supplied into the drum 12 to perform a drying cycle. To that end, the controller 110 may operate the heater 44 for a predetermined time.

[0073] For example, the controller 110 may operate the blowing fan 41 to supply dry air into the drum 12. Accordingly, dry air may be supplied into the drum 12 through the discharge port (e.g., the discharge port 41b of FIG. 1) of the blowing fan 41 and through the air inlet (e.g., the air inlet 45 of FIG. 1). The dry air may pass through the drum 12 and high-temperature humid air may be discharged through the air outlet (e.g., the air outlet 46 of FIG. 1).

[0074] According to an embodiment, the controller 110 may transmit control signals for operating components connected to the driving unit 200.

[0075] According to an embodiment, the driving unit 200 may be drivingly connected to the driving motor 13. The driving motor 13 may be connected to the drum 12, the pulsator 210, or the blowing fan 41 to operate the drum 12, the pulsator 210, or the blowing fan 41.

[0076] According to an embodiment, the controller 110 may determine a target operation time of the heater 44 to be operated during a drying cycle. The controller 110 may obtain a weight of a drying object before the drying cycle is performed. The drying object may be understood as laundry after washing, rinsing, and spinning cycles have been completed. The weight of the drying object may be referred to as a first weight.

[0077] According to an embodiment, the controller 110 may determine a target operation time of the heater 44 based on the first weight. For example, the controller 110 may determine a preset target operation time according to the first weight based on a database stored in the memory 113. The database may be understood as, e.g., a table in which a relationship between the first weight and the target operation time is set. The first weight and the target operation time may be linearly proportional.

[0078] According to an embodiment, the controller 110 may operate the heater 44 to heat dry air supplied into the drum 12 during a drying cycle. The controller 110 may transmit a control signal to the heater 44. For example, the control signal may be a switching signal. The switching signal may be a pulse signal having a predetermined current value that turns on (switching-on) or turns off (switching-off) the heater 44. The heater 44 that has received the control signal may repeat operation and stopping operation.

[0079] According to an embodiment, the controller 110 may operate or stop operating the heater 44 so that a temperature inside the drum 12 and / or a temperature of the dry air satisfies a preset temperature range during a drying cycle. To that end, the controller 110 may obtain a temperature inside the drum 12 or of the dry air from the temperature sensor 123.

[0080] For example, the controller 110 may repeat an operation cycle multiple times of operating the heater 44 for a predetermined time and then stopping operation for a predetermined time. Here, a predetermined time during which the heater 44 operates during a drying cycle may be referred to as "unit operation time," and a predetermined time during which operation stops after the unit operation time may be referred to as "unit idle time." The unit operation time and the unit idle time may be referred to as a "unit operation cycle."

[0081] For example, during a drying cycle, the heater 44 may be repeated for n unit operation cycles. The unit operation cycles may be composed of a first unit operation cycle, a second unit operation cycle, ..., a kth unit operation cycle, ..., an nth operation cycle in chronological order. Here, k and n are natural numbers of 1 or more, and n may be a natural number greater than or equal to k.

[0082] For example, the first unit operation cycle may include a first unit operation time and a first unit idle time.

[0083] For example, the second unit operation cycle may include a second unit operation time and a second unit idle time.

[0084] For example, the kth unit operation cycle may include a kth unit operation time and a kth unit idle time.

[0085] For example, the nth unit operation cycle may include an nth unit operation time and an nth unit idle time.

[0086] According to an embodiment, unit operation times and unit idle times constituting each unit operation cycle may be the same or different from each other.

[0087] According to an embodiment, as a drying cycle progresses, time of a unit operation cycle may decrease. In other words, as a drying cycle progresses, time for a temperature of dry air to reach a threshold range may decrease.

[0088] According to an embodiment, the controller 110 may operate the heater 44 for a unit operation time and then stop operation for a unit idle time so that a temperature of dry air satisfies a threshold range, and the controller 110 may count a total sum of unit operation times during which the heater 44 operates using the timer 115. A set of unit operation times may be referred to as "cumulative operation time."

[0089] According to an embodiment, the controller 110 may compare the cumulative operation time with the target operation time. The controller 110 may terminate a drying cycle in response to the cumulative operation time exceeding the target operation time.

[0090] According to an embodiment, a total sum of unit operation cycles may be less than or equal to time during which a drying cycle is substantially performed. In other words, the washing machine 1 may additionally perform a drying cycle for a predetermined time in case that a specific event occurs after the nth unit operation cycle ends. Specific events for additionally performing a drying cycle are described in detail in FIG. 4 and below.

[0091] According to an embodiment, because the controller 110 operates until the cumulative operation time of the heater 44 reaches the target operation time during a drying cycle, a termination point of the drying cycle may be determined without having a separate sensor. Because the controller 110 controls the heater 44 to operate so that the cumulative operation time reaches the target operation time during a drying cycle, the washing machine 100 may provide drying performance independently of factors affecting the drying cycle (e.g., amount of moisture included in laundry, temperature of cold water supplied into the condensation duct 43).

[0092] According to an embodiment, because the controller 110 operates until the cumulative operation time of the heater 44 reaches the target operation time, a drying cycle may be terminated at a point earlier than in case that a preset target drying time elapses. Accordingly, considering that most of the power consumed during a drying cycle is electrical energy required to operate the heater 44, the washing machine 100 may minimize power required to perform a drying cycle independently of factors affecting the drying cycle.

[0093] FIGS. 3 to 5 are operation flowcharts for the washing machine 1 (e.g., the washing machine 1 of FIG. 1 or the washing machine 100 of FIG. 2) to control a drying cycle according to an embodiment.

[0094] Referring to FIGS. 3 to 5, each control operation may be repeatedly performed as necessary, or some operations may be omitted. Further, the order of the control operations may be changed as necessary.

[0095] FIG. 3 is an operation flowchart for the washing machine 1 to control a drying cycle according to an embodiment.

[0096] According to an embodiment, the washing machine 1 may sense a weight of a drying object in operation 310.

[0097] For example, operation 310 may be performed after the washing machine 1 sequentially performs washing, rinsing, and spinning cycles. Here, the drying object may be understood as laundry that is introduced into the drum (e.g., the drum 12 of FIG. 1) and will undergo a drying cycle after washing, rinsing, and spinning cycles are performed.

[0098] For example, operation 310 may be performed independently of washing, rinsing, and spinning cycles. Here, the drying object may be understood as laundry on which a drying cycle is performed.

[0099] According to an embodiment, to sense a weight of a drying object, the washing machine 1 may obtain a current signal of the driving motor (e.g., the driving motor 13 of FIG. 1) obtained from the current sensor (e.g., the current sensor 125 of FIG. 2). The washing machine 1 may obtain a weight of the drying object based on a back electromotive force value generated in case that the driving motor 13 rotates the drum 12 and / or the pulsator (e.g., the pulsator 210 of FIG. 2). The weight of the drying object may be referred to as a first weight.

[0100] According to an embodiment, the washing machine 1 may determine a target operation time for operating the heater (e.g., the heater 44 of FIG. 1) based on the first weight in operation 320. Here, the target operation time may be understood as a time for which the washing machine 1 intends to operate the heater 44 in total during a drying cycle.

[0101] According to an embodiment, the target operation time may be proportional to the first weight. In other words, as a weight of a drying object sensed by the washing machine 1 increases, the target operation time may increase. For example, the target operation time may be linearly proportional to the first weight.

[0102] According to an embodiment, the washing machine 1 may retrieve a preset target operation time based on the first weight from the memory (e.g., the memory 113 of FIG. 2). The preset target operation time based on the first weight may be stored in the memory 113 in the form of a table.

[0103] According to an embodiment, the target operation time may be shorter than an initially preset time for which a drying cycle is performed.

[0104] According to an embodiment, the washing machine 1 may determine the target operation time based on a weight at the time when laundry was introduced into the drum before a washing cycle is performed (this is referred to as a third weight) and the first weight. In other words, the washing machine 1 may determine the target operation time by comparing the third weight, which is a weight of laundry before a washing cycle is performed, with the first weight.

[0105] For example, the washing machine 1 may predict an amount of moisture included in laundry before and after washing and spinning cycles are performed based on the first weight and the third weight. Accordingly, the washing machine 1 may also determine the target operation time based on the amount of moisture included in the laundry.

[0106] According to an embodiment, the washing machine 1 may operate the heater 44 so that a temperature of dry air satisfies a threshold range in operation 330. The washing machine 1 may operate or stop operating the heater 44 so that a temperature of dry air or the drum 12 satisfies a preset threshold range.

[0107] For example, the washing machine 1 may obtain a temperature of dry air supplied to the drum 12 from the temperature sensor 123. The temperature sensor 123 for obtaining the temperature of dry air may be provided on the drying duct (e.g., the drying duct 42 of FIG. 1) or on the air inlet (e.g., the air inlet 45 of FIG. 1).

[0108] For example, the washing machine 1 may obtain a temperature of dry air discharged from the drum 12 from the temperature sensor 123. The temperature sensor 123 for obtaining the temperature of dry air discharged from the drum 12 may be provided on the drying duct 42 or on the air outlet (e.g., the air outlet 46 of FIG. 1).

[0109] For example, the washing machine 1 may obtain a temperature inside the drum 12 from the temperature sensor 123. The temperature sensor 123 for obtaining the temperature inside the drum 12 may be provided inside the drum 12.

[0110] According to an embodiment, the washing machine 1 may operate or stop operating the heater 44 so that a preset threshold range is satisfied based on a temperature inside the drum 12 and / or of dry air obtained from the temperature sensor 123.

[0111] For example, the washing machine 1 may operate the heater 44 so that a temperature of dry air obtained from the temperature sensor 123 satisfies between a first threshold temperature and a second threshold temperature. For example, the washing machine 1 may operate the heater 44 in case that a temperature of dry air becomes lower than the first threshold temperature, and may stop operating the heater 44 in case that the temperature of dry air becomes higher than the second threshold temperature. Here, time from time t1 in case that the heater 44 is operated because the temperature of dry air becomes lower than the first threshold temperature to time t1' when the heater 44 stops operating because the temperature of dry air becomes higher than the second threshold temperature may be referred to as "(first) unit operation time." At time t2 when the temperature of dry air becomes lower than the first threshold temperature again, the washing machine 1 may operate the heater 44 again. Time from the time t1' to the time t2 may be referred to as "(first) unit idle time." The (first) unit operation time and the (first) unit idle time combined may be referred to as a (first) unit operation cycle.

[0112] According to an embodiment, the washing machine 1 may operate and then stop operating the heater 44 repeatedly at least multiple times. For example, during a drying cycle, the washing machine 1 may operate the heater 44 for n unit operation cycles.

[0113] According to an embodiment, the washing machine 1 may terminate a drying cycle in case that a cumulative time of the heater 44 exceeds the target operation time in operation 340. To that end, the timer (e.g., the timer 115 of FIG. 2) may transmit to the washing machine 1 a cumulative operation time, which is time during which the heater 44 operates during a drying cycle. The washing machine 1 may terminate a drying cycle in response to the cumulative operation time of the heater 44 exceeding a preset target operation time.

[0114] According to an embodiment, the target operation time may be shorter than an initially preset time for which a drying cycle is performed. Therefore, the washing machine 1 may terminate the drying cycle at a point earlier than a preset drying cycle required time.

[0115] According to an embodiment, as the washing machine 1 determines a point to terminate a drying cycle based on the cumulative operation time of the heater 44, a termination point of a drying cycle may be determined without having a separate sensor. Further, the washing machine 1 may minimize power consumption independently of factors affecting a drying cycle (e.g., amount of moisture included in laundry, temperature of cold water supplied into the condensation duct 43).

[0116] FIG. 4 is an operation flowchart for the washing machine 1 to control a drying cycle according to an embodiment.

[0117] At least some operations of FIG. 4 may correspond to operations illustrated in FIG. 3. Therefore, differences are mainly described.

[0118] According to an embodiment, the washing machine 1 may sense a weight of a drying object, i.e., a first weight, in operation 410. Operation 410 may correspond to all or some of operation 310.

[0119] According to an embodiment, the washing machine 1 may determine a target operation time of the heater 44 based on the first weight in operation 420. Operation 420 may correspond to all or some of operation 320.

[0120] According to an embodiment, the washing machine 1 may operate the heater 44 so that a temperature of dry air satisfies a threshold range in operation 430. Operation 430 may correspond to all or some of operation 330.

[0121] According to an embodiment, the washing machine 1 may determine whether a cumulative operation time of the heater 44 exceeds the target operation time in operation 440. At least a portion of operation 440 may correspond to all or some of operation 340.

[0122] In response to the cumulative operation time of the heater 44 exceeding the target operation time, the washing machine 1 may determine whether a drive rate of the heater 44 is less than a threshold level in operation 450. Here, a drive rate of the heater 44 may be defined based on a unit operation time and a unit idle time included in a unit operation cycle. The drive rate may be defined as the unit operation time relative to the unit operation cycle. In other words, the drive rate may be defined as a value obtained by dividing the unit operation time by the unit operation cycle. However, not limited thereto, the drive rate may be defined in various ways. For example, the drive rate may be defined as a value obtained by dividing the unit operation time by the unit idle time. Hereinafter, this document will describe by defining the drive rate as a value obtained by dividing the unit operation time by the unit operation cycle.

[0123] According to an embodiment, the drive rate may include at least multiple drive rates corresponding to unit operation cycles. The drive rate may include, e.g., a first drive rate, a second drive rate, ..., a kth drive rate, ..., an nth drive rate. Here, n is a natural number of 2 or more.

[0124] For example, the first drive rate may be defined as a value obtained by dividing a first unit operation time by a first unit operation cycle.

[0125] For example, the second drive rate may be defined as a value obtained by dividing a second unit operation time by a second unit operation cycle.

[0126] For example, the kth drive rate may be defined as a value obtained by dividing a kth unit operation time by a kth unit operation cycle.

[0127] For example, the nth drive rate may be defined as a value obtained by dividing an nth unit operation time by an nth unit operation cycle.

[0128] For example, if a kth unit operation time included in a kth unit operation cycle is 80 seconds and a kth unit idle time included in the kth unit operation cycle is 60 seconds, the kth drive rate may be derived as about 0.57. For example, if the drive rate is defined as a value obtained by dividing the unit operation time by the unit idle time, the kth drive rate may be derived as about 1.33.

[0129] According to an embodiment, as a drying cycle is performed, the drive rate may decrease. In other words, as a drying cycle is performed, time (unit operation time) for which the washing machine 1 operates the heater 44 to heat dry air to a preset temperature (e.g., first threshold temperature) may decrease. Further, time (unit idle time) during which the washing machine 1 stops operating the heater 44 while dry air heated to the first threshold temperature cools to a second threshold temperature may increase or remain constant. Accordingly, as a drying cycle is performed, a ratio of unit operation time included in a unit operation cycle may decrease, causing the drive rate to decrease.

[0130] According to an embodiment, the washing machine 1 may store a drive rate of the heater 44 as a drying cycle is performed in the memory (e.g., the memory 113 of FIG. 2). The washing machine 1 may determine whether a drive rate of the heater 44 has reached below a preset threshold level. The preset threshold level may be, e.g., 0.5. In other words, the washing machine 1 may determine whether there was a unit operation cycle in which a unit operation time was smaller than a unit idle time during a drying cycle.

[0131] If there is no unit operation cycle in which a drive rate of the heater 44 reached below the threshold level, the washing machine 1 may perform an additional drying cycle in operation 460. If a drive rate of the heater 44 has not reached below the threshold level, the washing machine 1 may determine that a drying cycle should be additionally performed on the drying object. Therefore, even in case that the target operation time is exceeded, the washing machine 1 may perform a drying cycle for a preset target drying time and then terminate the drying cycle.

[0132] According to an embodiment, because the washing machine 1 determines a point to terminate a drying cycle based on a drive rate of the heater 44, a drying cycle may be additionally performed to remove moisture included in the drying object so that a target degree of drying for the drying object may be reached.

[0133] FIG. 5 is an operation flowchart for the washing machine 1 to control a drying cycle according to an embodiment.

[0134] At least some operations of FIG. 5 may correspond to operations illustrated in FIG. 3 or 4. Therefore, differences are mainly described.

[0135] According to an embodiment, the washing machine 1 may sense a weight of a drying object, i.e., a first weight, in operation 510. Operation 510 may correspond to at least a portion of operation 310 or operation 410.

[0136] According to an embodiment, the washing machine 1 may determine a target operation time of the heater 44 based on the first weight in operation 520. Operation 520 may correspond to at least a portion of operation 320 or operation 420.

[0137] According to an embodiment, the washing machine 1 may operate the heater 44 so that a temperature of dry air satisfies a threshold range in operation 530. Operation 530 may correspond to at least a portion of operation 330 or operation 430.

[0138] According to an embodiment, the washing machine 1 may determine whether a cumulative operation time of the heater 44 exceeds the target operation time in operation 540. Operation 540 may correspond to at least a portion of operation 340 or operation 440.

[0139] In case that the cumulative operation time of the heater 44 exceeds the target operation time, the washing machine 1 may determine whether there is a unit operation cycle in which a drive rate of the heater 44 reached below a threshold level in operation 550. Operation 550 may correspond to at least a portion of operation 450.

[0140] If there is a unit operation cycle in which a drive rate of the heater 44 reached below the threshold level, the washing machine 1 may sense a weight of a drying object stored in the drum 12 in operation 560. The weight of the drying object may be defined as a "second weight."

[0141] According to an embodiment, the second weight may be the same as or different from the first weight. For example, the second weight, which is a weight of the drying object after a drying cycle has been performed, may be smaller compared to the first weight.

[0142] According to an embodiment, the washing machine 1 may determine whether a degree of drying of the drying object satisfies a threshold level in operation 570. The degree of drying of the drying object may be determined based on a weight of wet laundry before a drying cycle is performed (i.e., after a spinning cycle is performed) and a weight of dried laundry after a drying cycle is performed.

[0143] According to an embodiment, the degree of drying may be defined as a change value of a weight of laundry relative to the first weight. In other words, degree of drying [%] = (first weight - second weight) / (first weight) * 100[%]. For example, if a weight of wet laundry after a spinning cycle ends (first weight) is 10kg and a weight of laundry after a drying cycle is performed (second weight) is 9.9kg, the degree of drying may be derived as (10-9.9) / 10*100=1%.

[0144] According to an embodiment, the washing machine 1 may determine a termination point of a drying cycle based on a degree of drying of a drying object. Accordingly, the washing machine 1 may determine a termination point of a drying cycle to achieve a target degree of drying for a drying object. For example, the target degree of drying may be set to 0.2 to 0.3.

[0145] In case that a degree of drying of a drying object reaches below a threshold level, the washing machine 1 may terminate a drying cycle. For example, the washing machine 1 may terminate a drying cycle at a point earlier than when a target drying time elapses.

[0146] According to an embodiment, if there is no unit operation cycle in which a drive rate of the heater 44 reached below a threshold level, or if a degree of drying of a drying object does not satisfy a threshold level, the washing machine 1 may additionally perform a drying cycle in operation 580. Operation 580 may correspond to at least a portion of operation 460. The washing machine 1 may perform a drying cycle for a preset target drying time and then terminate the drying cycle.

[0147] According to an embodiment, the washing machine 1 may minimize power required to perform a drying cycle independently of factors affecting the drying cycle while simultaneously optimizing a degree of drying of a drying object.

[0148] FIG. 6 illustrates a graph of current of a switching signal for operating heater 44 (e.g., the heater 44 of FIG. 1) during a drying cycle and a graph illustrating temperature change of dry air according to an embodiment.

[0149] Referring to FIG. 6, while a drying cycle is performed, washing machine (e.g., the washing machine 1 of FIG. 1) may operate or stop operating the heater 44 so that a temperature of dry air satisfies a preset threshold range. Accordingly, the controller (e.g., the controller 110 of FIG. 2) may repeatedly output a control signal for operating the heater 44 in response to time elapse during a drying cycle. The control signal may be, e.g., a pulse-type signal having a predetermined current. The predetermined current may be, e.g., I h . Graph (a) may be understood as illustrating a pulse-type control signal that the controller 110 outputs to the heater 44. Graph (b) may be understood as illustrating a temperature of dry air measured by the temperature sensor (e.g., the temperature sensor 123 of FIG. 2) over time. However, graph (b) is not limited to a temperature of dry air and may also be a temperature inside the drum (e.g., the drum 12 of FIG. 1) measured by the temperature sensor 123.

[0150] According to an embodiment, the washing machine 1 may operate or stop operating the heater 44 based on a temperature of dry air obtained from the temperature sensor 123. For example, the washing machine 1 may operate the heater 44 so that a temperature of dry air satisfies a preset threshold range. The threshold range may be set to, e.g., a first threshold temperature T1 to a second threshold temperature T2.

[0151] According to an embodiment, in case that a temperature of dry air becomes lower than the first threshold temperature T1, the washing machine 1 may output a control signal for operating the heater 44. Accordingly, the heater 44 may heat the dry air. In case that the temperature of the dry air reaches the second threshold temperature T2, the washing machine 1 may stop outputting the control signal. As the operation of the heater 44 stops, the dry air may be cooled.

[0152] According to an embodiment, due to operation of the heater 44, the dry air may be gradually heated. The temperature of the dry air may increase in the form of a logarithmic function corresponding to an operation time of the dry air, for example. However, not limited thereto, the temperature of the dry air may increase in the form of an exponential function corresponding to an operation time of the dry air, or may increase in the form of a linear function with a constant slope corresponding to an operation time of the dry air.

[0153] According to an embodiment, as the operation of the heater 44 stops, the dry air may be gradually cooled. The temperature of the dry air may decrease in the form of a logarithmic function corresponding to an operation time of the dry air, for example. However, not limited thereto, the temperature of the dry air may decrease in the form of an exponential function corresponding to an operation time of the dry air, or may decrease in the form of a linear function with a constant slope corresponding to an operation time of the dry air.

[0154] According to an embodiment, at time t1, the washing machine 1 may output a control signal for operating the heater 44 in response to a temperature of the dry air reaching the first threshold temperature T1. The washing machine 1 may output the control signal until time t1' when the temperature of the dry air reaches the second threshold temperature T2. An interval from the time t1 to the time t1' may be defined as a first unit operation time d#1. An interval from the time t1' to the time t2 may be defined as a first unit idle time d#1'. An interval from the time t1 to the time t2 may be defined as a first unit operation cycle p#1. The washing machine 1 may derive a first drive rate, which is a ratio of the first unit operation time d#1 to the first unit operation cycle p#1.

[0155] According to an embodiment, at time t2, the washing machine 1 may output a control signal for operating the heater 44 in response to a temperature of the dry air reaching the first threshold temperature T1. The washing machine 1 may output the control signal until time t2' when the temperature of the dry air reaches the second threshold temperature T2. An interval from the time t2 to the time t2' may be defined as a second unit operation time d#2. An interval from the time t2' to the time t3 may be defined as a second unit idle time d#2'. An interval from the time t2 to the time t3 may be defined as a second unit operation cycle p#2. The washing machine 1 may derive a second drive rate, which is a ratio of the second unit operation time d#2 to the second unit operation cycle p#2.

[0156] According to an embodiment, at time t3, the washing machine 1 may output a control signal for operating the heater 44 in response to a temperature of the dry air reaching the first threshold temperature T1. The washing machine 1 may output the control signal until time t3' when the temperature of the dry air reaches the second threshold temperature T2. An interval from the time t3 to the time t3' may be defined as a third unit operation time d#3. An interval from the time t3' to the time t4 may be defined as a third unit idle time d#3'. An interval from the time t3 to the time t4 may be defined as a third unit operation cycle p#3. The washing machine 1 may derive a third drive rate, which is a ratio of the third unit operation time d#3 to the third unit operation cycle p#3.

[0157] According to an embodiment, at time t(n-2), the washing machine 1 may output a control signal for operating the heater 44 in response to a temperature of the dry air reaching the first threshold temperature T1. The washing machine 1 may output the control signal until time t(n-2)' when the temperature of the dry air reaches the second threshold temperature T2. An interval from the time t(n-2) to the time t(n-2)' may be defined as a n-2th unit operation time d#(n-2). An interval from the time t(n-2)' to the time t(n-1) may be defined as a n-2th unit idle time d#(n-2'). An interval from the time t(n-2) to the time t(n-1) may be defined as a n-2th unit operation cycle p#(n-2). The washing machine 1 may derive a n-2th drive rate, which is a ratio of the n-2th unit operation time d#(n-2) to the n-2th unit operation cycle p#(n-2).

[0158] According to an embodiment, at time t(n-1), the washing machine 1 may output a control signal for operating the heater 44 in response to a temperature of the dry air reaching the first threshold temperature T1. The washing machine 1 may output the control signal until time t(n-1)' when the temperature of the dry air reaches the second threshold temperature T2. An interval from the time t(n-1) to the time t(n-1)' may be defined as a n-1th unit operation time d#(n-1). An interval from the time t(n-1)' to the time tn may be defined as a n-1th unit idle time d#(n-1'). An interval from the time t(n-1) to the time tn may be defined as a n-1th unit operation cycle p#(n-1). The washing machine 1 may derive a n-1th drive rate, which is a ratio of the n-1th unit operation time d#(n-1) to the n-1th unit operation cycle p#(n-1).

[0159] According to an embodiment, at time tn, the washing machine 1 may output a control signal for operating the heater 44 in response to a temperature of the dry air reaching the first threshold temperature T1. The washing machine 1 may output the control signal until time tn' when the temperature of the dry air reaches the second threshold temperature T2. An interval from the time tn to the time tn' may be defined as an nth unit operation time d#n. An interval from the time tn' to the time tf may be defined as an nth unit idle time d#n'. An interval from the time tn to the time tf may be defined as an nth unit operation cycle p#n. The washing machine 1 may derive an nth drive rate, which is a ratio of the nth unit operation time d#n to the nth unit operation cycle p#n.

[0160] According to an embodiment, the washing machine 1 may derive a drive rate based on consecutive unit idle times and unit operation times.

[0161] For example, the washing machine 1 may derive a drive rate according to a ratio of the second unit operation time d#2 to a combined time of the first unit idle time d#1' and the second unit operation time d#2.

[0162] For example, the washing machine 1 may derive a drive rate according to a ratio of the third unit operation time d#3 to a combined time of the second unit idle time d#2' and the third unit operation time d#3.

[0163] For example, the washing machine 1 may derive a drive rate according to a ratio of the n-1th unit operation time d#(n-1) to a combined time of the n-2th unit idle time d#(n-2') and the n-1th unit operation time d#(n-1).

[0164] For example, the washing machine 1 may derive a drive rate according to a ratio of the nth unit operation time d#n to a combined time of the n-1th unit idle time d#(n-1') and the nth unit operation time d#n.

[0165] According to an embodiment, at time tf, the washing machine 1 may terminate a drying cycle.

[0166] According to an embodiment, as time elapses during a drying cycle, time for heating a temperature of dry air from the first threshold temperature T1 to the second threshold temperature T2 may decrease. Further, as time elapses during a drying cycle, time for a temperature of dry air to cool from the second threshold temperature T2 to the first threshold temperature T1 may remain constant or increase. Accordingly, as time elapses during a drying cycle, a unit operation rate may decrease.

[0167] According to an embodiment, the washing machine 1 may determine a target operation time based on the first weight, which is a weight of a drying object. The washing machine 1 may terminate a drying cycle in case that a cumulative operation time, which is a sum of at least multiple unit operation times, reaches the target operation time.

[0168] According to an embodiment, in case that the cumulative operation time reaches the target operation time, the washing machine 1 may determine whether there was a unit operation cycle during a drying cycle in which a drive rate of the heater 44 reached below a preset threshold level. The preset threshold level may be, e.g., 0.5. If there is a unit operation cycle in which a drive rate of the heater 44 reached below the threshold level, the washing machine 1 may terminate a drying cycle. If there is no unit operation cycle in which a drive rate of the heater 44 reached below the threshold level, the washing machine 1 may additionally perform a drying cycle for a preset time and then terminate the drying cycle.

[0169] According to an embodiment, in case that the cumulative operation time reaches the target operation time, the washing machine 1 may sense a third weight, which is a weight of a drying object. The washing machine 1 may derive a degree of drying of the drying object by calculating an amount of change of the third weight relative to the first weight. If a degree of drying of the drying object satisfies a threshold level, the washing machine 1 may terminate a drying cycle. If a degree of drying of the drying object does not satisfy the threshold level, the washing machine 1 may additionally perform a drying cycle for a preset time and then terminate the drying cycle.

[0170] A washing machine (e.g., the washing machine 1 of FIG. 1 or the washing machine 100 of FIG. 2) according to an embodiment of the disclosure may include a heater 44 heating dry air to be supplied into an interior of a drum 12, a temperature sensor 123 sensing a temperature of the dry air, and a controller 110 controlling operation of the heater 44 in response to activation of a drying function. The controller 110 may control (330) whether to operate the heater 44 so that the temperature of the dry air is maintained constantly with respect to a target control temperature in case that a drying cycle is initiated by the activation of the drying function, and may terminate (340) the drying cycle in response to arrival of a drying termination time within a preset reference operation section for initiation or termination of the drying cycle. The drying termination time may be identified by a weight of a drying object obtained in response to the activation of the drying function.

[0171] In the washing machine (1, 100) according to an embodiment of the disclosure, the controller 110 may determine that the drying termination time has arrived in case that a cumulative operation time of the heater 44 measured after the drying cycle is initiated reaches a threshold cumulative operation time. The threshold cumulative operation time may be set by the obtained weight of the drying object.

[0172] In the washing machine (1, 100) according to an embodiment of the disclosure, the controller 110 may determine (450) whether to resume the drying cycle based on a drive rate of the heater 44 upon terminating (340) the drying cycle.

[0173] In the washing machine (1, 100) according to an embodiment of the disclosure, the controller 110 may determine (460) to resume the drying cycle in case that the drive rate of the heater 44 exceeds a predetermined threshold.

[0174] In the washing machine (1, 100) according to an embodiment of the disclosure, the controller 110 may obtain the drive rate according to a ratio of a unit operation section of the heater 44 to a unit idle section of the heater 44. The unit idle section is continuous with the unit operation section, the unit operation section is an elapsed time between a start time and an end time indicating a unit section in which the heater 44 operates, and the unit idle section may be one of an elapsed time between the end time and a start time indicating a unit section in which the heater 44 does not operate, or an elapsed time between the end time and the drying termination time.

[0175] In the washing machine (1, 100) according to an embodiment of the disclosure, the controller 110 may obtain the drive rate according to a ratio of a unit operation section of the heater 44 to a unit idle section of the heater 44. The unit operation section is continuous with the unit idle section, the unit idle section is an elapsed time between an end time and a start time indicating a unit section in which the heater 44 does not operate, and the unit operation time may be an elapsed time between the start time and an end time indicating a unit section in which the heater 44 operates.

[0176] In the washing machine (1, 100) according to an embodiment of the disclosure, the controller 110 may terminate the resumed drying cycle at an end time of the preset reference operation section.

[0177] In the washing machine (1, 100) according to an embodiment of the disclosure, the controller 110 may terminate the resumed drying cycle in case that the drive rate is less than the predetermined threshold.

[0178] In the washing machine (1, 100) according to an embodiment of the disclosure, the controller 110 may measure the weight of the drying object in case that a weight sensing cycle is initiated by the activation of the drying function, and may initiate the drying cycle in case that the weight sensing cycle is completed.

[0179] In the washing machine (1, 100) according to an embodiment of the disclosure, the controller 110 may control the heater 44 to operate in case that the temperature of the dry air is substantially lower than the target control temperature, and may control operation of the heater 44 to stop in case that the temperature of the dry air is substantially higher than the target control temperature.

[0180] A control method of the washing machine (1, 100) according to an embodiment of the disclosure may include an operation (330) of controlling whether to operate the heater 44 so that the temperature of the dry air is maintained constantly with respect to a target control temperature in case that a drying cycle is initiated by the activation of the drying function, and an operation (340) of terminating the drying cycle in response to arrival of a drying termination time within a preset reference operation section for initiation or termination of the drying cycle. The drying termination time may be identified (320) by a weight of a drying object obtained in response to the activation of the drying function.

[0181] The control method of the washing machine (1, 100) according to an embodiment of the disclosure may include an operation (340) of determining that the drying termination time has arrived in case that a cumulative operation time of the heater 44 measured after the drying cycle is initiated reaches a threshold cumulative operation time. The threshold cumulative operation time may be set by the obtained weight of the drying object.

[0182] The control method of the washing machine (1, 100) according to an embodiment of the disclosure may include an operation of determining (450) whether to resume the drying cycle based on a drive rate of the heater 44 upon terminating (340, 440) the drying cycle.

[0183] The control method of the washing machine (1, 100) according to an embodiment of the disclosure may include an operation (460) of determining to resume the drying cycle in case that the drive rate of the heater 44 exceeds a predetermined threshold.

[0184] The control method of the washing machine (1, 100) according to an embodiment of the disclosure may include an operation of obtaining the drive rate according to a ratio of a unit operation section of the heater 44 to a unit idle section of the heater 44. The unit idle section is continuous with the unit operation section, the unit operation section is an elapsed time between a start time and an end time indicating a unit section in which the heater 44 operates, and the unit idle section may be one of an elapsed time between the end time and a start time indicating a unit section in which the heater 44 does not operate, or an elapsed time between the end time and the drying termination time.

[0185] The control method of the washing machine (1, 100) according to an embodiment of the disclosure may include an operation of obtaining the drive rate according to a ratio of a unit operation section of the heater 44 to a unit idle section of the heater 44. The unit operation section is continuous with the unit idle section, the unit idle section is an elapsed time between an end time and a start time indicating a unit section in which the heater 44 does not operate, and the unit operation time may be an elapsed time between the start time and an end time indicating a unit section in which the heater 44 operates.

[0186] The control method of the washing machine (1, 100) according to an embodiment of the disclosure may include an operation of terminating the resumed drying cycle at an end time of the preset reference operation section.

[0187] The control method of the washing machine (1, 100) according to an embodiment of the disclosure may include an operation of terminating the resumed drying cycle in case that the drive rate is less than the predetermined threshold.

[0188] The control method of the washing machine (1, 100) according to an embodiment of the disclosure may include an operation of controlling the heater 44 to operate in case that the temperature of the dry air is substantially lower than the target control temperature and an operation of controlling operation of the heater 44 to stop in case that the temperature of the dry air is substantially higher than the target control temperature.

[0189] The terms as used herein are provided merely to describe some embodiments thereof, but are not intended to limit the disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, each of such phrases as "A or B," "at least one of A and B," "at least one of A or B," "A, B, or C," "at least one of A, B, and C," and "at least one of A, B, or C," may include all possible combinations of the items enumerated together in a corresponding one of the phrases. As used herein, the term 'and / or' should be understood as encompassing any and all possible combinations by one or more of the enumerated items. As used herein, the terms "include," "have," and "comprise" are used merely to designate the presence of the feature, component, part, or a combination thereof described herein, but use of the term does not exclude the likelihood of presence or adding one or more other features, components, parts, or combinations thereof. As used herein, the terms "first" and "second" may modify various components regardless of importance and / or order and are used to distinguish a component from another without limiting the components.

[0190] As used herein, the terms "configured to" may be interchangeably used with the terms "suitable for," "having the capacity to," "designed to," "adapted to," "made to," or "capable of" depending on circumstances. The term "configured to" does not essentially mean "specifically designed in hardware to." Rather, the term "configured to" may mean that a device can perform an operation together with another device or parts. For example, a 'device configured (or set) to perform A, B, and C' may be a dedicated device to perform the corresponding operation or may mean a general-purpose device capable of various operations including the corresponding operation.

[0191] Meanwhile, the terms "upper side", "lower side", and "front and rear directions" used in the disclosure are defined with respect to the drawings, and the shape and position of each component are not limited by these terms.

[0192] In the disclosure, the above-described description has been made mainly of specific embodiments, but the disclosure is not limited to such specific embodiments, but should rather be appreciated as covering all various modifications, equivalents, and / or substitutes of various embodiments.

Examples

Embodiment Construction

[0012]Hereinafter, embodiments of the disclosure are described in detail with reference to the drawings so that those skilled in the art to which the disclosure pertains may easily practice the disclosure. However, the disclosure may be implemented in other various forms and is not limited to the embodiments set forth herein. The same or similar reference denotations may be used to refer to the same or similar elements throughout the specification and the drawings. Further, for clarity and brevity, no description is made of well-known functions and configurations in the drawings and relevant descriptions.

[0013]Further, the terms to be described below is defined as follows. Laundry introduced into washing machine 1 and disposed inside drum 12 before washing, rinsing, and spinning cycles are performed is referred to as "washing object." Laundry before washing machine 1 performs a drying cycle to dry the washing object is referred to as "drying object." The drying object that has been ...

Claims

1. A washing machine (1, 100), comprising: a heater (44) heating dry air to be supplied into an interior of a drum (12); a temperature sensor (123) sensing a temperature of the dry air; and a controller (110) controlling operation of the heater (44) in response to activation of a drying function, wherein the controller (110): controls (330) whether to operate the heater (44) to maintain constant the temperature of the dry air with respect to a target control temperature in case that a drying cycle is initiated by the activation of the drying function, and terminates (340) the drying cycle in response to arrival of a drying termination time within a preset reference operation section for initiation or termination of the drying cycle, and wherein the drying termination time is identified by a weight of a drying object obtained in response to the activation of the drying function.

2. The washing machine (1, 100) of claim 1, wherein the controller (110) determines that the drying termination time has arrived in case that a cumulative operation time of the heater (44) measured after the drying cycle is initiated reaches a threshold cumulative operation time, and wherein the threshold cumulative operation time is set by the obtained weight of the drying object.

3. The washing machine (1, 100) of claim 1 or 2, wherein the controller (110) determines (450) whether to resume the drying cycle based on a drive rate of the heater (44) upon terminating (340) the drying cycle.

4. The washing machine (1, 100) of claim 3, wherein the controller (110) determines (460) to resume the drying cycle in case that the drive rate of the heater (44) exceeds a predetermined threshold.

5. The washing machine (1, 100) of claim 4, wherein the controller (110) obtains the drive rate according to a ratio of a unit operation section of the heater (44) to a unit idle section of the heater (44), wherein the unit idle section is continuous with the unit operation section, wherein the unit operation section is an elapsed time between a start time and an end time indicating a unit section in which the heater (44) operates, and wherein the unit idle section is one of an elapsed time between the end time and a start time indicating a unit section in which the heater (44) does not operate, or an elapsed time between the end time and the drying termination time.

6. The washing machine (1, 100) of claim 4, wherein the controller (110) obtains the drive rate according to a ratio of a unit operation section of the heater (44) to a unit idle section of the heater (44), wherein the unit operation section is continuous with the unit idle section, wherein the unit idle section is an elapsed time between an end time and a start time indicating a unit section in which the heater (44) does not operate, and wherein the unit operation time is an elapsed time between the start time and an end time indicating a unit section in which the heater (44) operates.

7. The washing machine (1, 100) of claim 3 or 4, wherein the controller (110) terminates the resumed drying cycle at an end time of the preset reference operation section.

8. The washing machine (1, 100) of claim 4, wherein the controller (110) terminates the resumed drying cycle in case that the drive rate is less than the predetermined threshold.

9. The washing machine (1, 100) of claim 1, wherein the controller (110): measures the weight of the drying object in case that a weight sensing cycle is initiated by the activation of the drying function; and initiates the drying cycle in case that the weight sensing cycle is completed.

10. The washing machine (1, 100) of claim 1, wherein the controller (110): controls the heater (44) to operate in case that the temperature of the dry air is substantially lower than the target control temperature; and controls operation of the heater (44) to stop in case that the temperature of the dry air is substantially higher than the target control temperature.

11. A method for a washing machine (1, 100) to control operation of a heater (44) in response to activation of a drying function, the method comprising: controlling (330) whether to operate the heater (44) to maintain constant a temperature of dry air with respect to a target control temperature in case that a drying cycle is initiated by the activation of the drying function; and terminating (340) the drying cycle in response to arrival of a drying termination time within a preset reference operation section for initiation or termination of the drying cycle, wherein the drying termination time is identified (320) by a weight of a drying object obtained in response to the activation of the drying function.

12. The method of claim 11, comprising determining (340) that the drying termination time has arrived in case that a cumulative operation time of the heater (44) measured after the drying cycle is initiated reaches a threshold cumulative operation time, wherein the threshold cumulative operation time is set by the obtained weight of the drying object.

13. The method of claim 11 or 12, comprising determining (450) whether to resume the drying cycle based on a drive rate of the heater (44) upon terminating (340, 440) the drying cycle.

14. The method of claim 13, comprising determining (460) to resume the drying cycle in case that the drive rate of the heater (44) exceeds a predetermined threshold.

15. The method of claim 14, comprising obtaining the drive rate according to a ratio of a unit operation time of the heater (44) to a unit idle section of the heater (44), wherein the unit idle section is continuous with the unit operation time, wherein the unit operation time is an elapsed time between a start time and an end time indicating a unit section in which the heater (44) operates, and wherein the unit idle section is one of an elapsed time between the end time and a start time indicating a unit section in which the heater (44) does not operate, or an elapsed time between the end time and the drying termination time.

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