Patent Description:
In general, refrigerators are home appliances for storing foods at a low temperature in a storage chamber that is covered by a door. The refrigerator may cool the inside of the storage space by using cold air to store the stored food in a refrigerated or frozen state. Generally, an ice maker for making ice is provided in the refrigerator. The ice maker makes ice by cooling water after accommodating the water supplied from a water supply source or a water tank into a tray. The ice maker may separate the made ice from the ice tray in a heating manner or twisting manner.

As described above, the ice maker through which water is automatically supplied, and the ice automatically separated may be opened upward so that the mode ice is pumped up.

As described above, the ice made in the ice maker may have at least one flat surface such as crescent or cubic shape.

When the ice has a spherical shape, it is more convenient to use the ice, and also, it is possible to provide different feeling of use to a user. Also, even when the made ice is stored, a contact area between the ice cubes may be minimized to minimize a mat of the ice cubes.

An ice maker is disclosed in Korean Registration No. <CIT> that is a prior art document.

The ice maker disclosed in the prior art document includes an upper tray in which a plurality of upper cells, each of which has a hemispherical shape, are arranged, and which includes a pair of link guide parts extending upward from both side ends thereof, a lower tray in which a plurality of upper cells, each of which has a hemispherical shape and which is rotatably connected to the upper tray, a rotation shaft connected to rear ends of the lower tray and the upper tray to allow the lower tray to rotate with respect to the upper tray, a pair of links having one end connected to the lower tray and the other end connected to the link guide part, and an upper ejecting pin assembly connected to each of the pair of links in at state in which both ends thereof are inserted into the link guide part and elevated together with the upper ejecting pin assembly.

In the case of the prior art document, the ice maker further includes the ice separation heater which heats the upper cell for ice separation, but in a case in which the ice separation heater has a breakdown due to disconnection or the like, there are no methods and countermeasures to detect the breakdown of the ice separation heater, so ice separation may not smooth.

In addition, when the ice separation heater has a breakdown, in a case in which the ice separation is performed as it is, damage to the upper ejecting pin assembly for the ice separation may occur, and there is a possibility that the damaged debris flows into the ice bin.

In addition, in a case in which the operation of the ice maker is stopped when the ice separation heater has a breakdown, ice may continue to cool inside the tray of the ice maker, resulting in a problem in which the ice maker is bound to the ice.

<CIT> presents a method of controlling an ice making assembly for a refrigerator, the method comprising: initiating an ice making mode; supplying water to an ice recess formed in a tray, the tray ready to receive a rod; contacting the water with the rod to remove heat from the water; intermittently operating a heater disposed at the tray to maintain the tray at a temperature above freezing; and controlling the operation of a cooling fan to selectively supply cooling air to the rod.

<CIT> presents an ice maker comprising a flow-detecting unit detecting the pressure of input water input into an ice tray for a refrigerator; a temperature sensor installed on a side of the ice tray, to detect the temperature of ice; an ice size control unit manually controlling the water supply flow to make the size of a piece of ice each different; a motor rotating a shaft mounted to the middle part of the ice tray and discharge ice in the ice tray to the outside; a motor drive unit to drive the motor; a data storage unit in which drive time data of a heater and the water supply time data of a water supply valve by the flow-detecting unit and the temperature sensor is stored and motor drive time date is stored in applying a motor drive signal; and a control unit generating a drive control signal to the motor when an ice discharge signal is generated, receiving a detection signal from the flow-detecting unit and the temperature sensor, and controlling the opening and shutting of the water supply valve.

<CIT> presents an icing machine of a refrigerator for making ice balls. The ice machine comprises an icing tray combined of a first part and a second part formed semispherical to complete one sphere and supplied with water at an inner hollow portion to produce ice balls; a heater installed at the icing tray; and a driving unit formed with a motor opening/closing the icing tray. The heater is a planar heater to be contacted on the first and second parts of the icing tray. A water supply port is formed at the upper side of the icing tray.

<CIT> relates to an ice making apparatus comprising a lower body, an upper body placed on top of the lower body, a lower insulating part placed in the lower body, an upper insulating part placed in the upper body, an ice mold placed between the upper insulating part and the lower insulating part so as to form at least one ice cell, having at least one filler opening provided on its upper surface and a discharge opening provided on its lower surface, and a cut-out into which water enters, provided so as to be below the ice mold and in the lower insulating part.

Embodiments provide a refrigerator which is capable of determining a breakdown of an ice separation heater, and a method for controlling the same.

Embodiments provide a refrigerator which is easy to maintain and repair by outputting a breakdown notification in response to a breakdown of an ice separation heater, and a method for controlling the same.

Embodiments provide a refrigerator which is capable of smoothly separating ice by turning on a transparent ice heater in response to a breakdown of the ice separation heater, and a method for controlling the same.

Embodiments provide a refrigerator which is capable of preventing other components from being damaged due to a breakdown of the ice separation heater and securing the reliability of each operation part, and a method for controlling the same.

Embodiments provide a refrigerator which is capable of applying an optimum heating amount by varying the amount for ice separation heating according to the degree of cooling of the ice maker, and a method for controlling the same.

A refrigerator according to an aspect includes a controller configured to turn on a heater so that the ice inside the ice making cell is easily separated from the trays. The heater is positioned at a side of a first tray or a second tray forming an ice making cell being a space in which water is phase-changed into ice by cold air.

The controller controls the heater to be turned off when a temperature sensed by the second temperature sensor reaches a first turn-off reference temperature greater than zero after a first reference time elapses in a state in which the heater is turned on.

The controller may determine that a first heater has a breakdown if the first heater is not turned off until reaching a second reference time greater than the first reference time after the heater is turned on.

The refrigerator may further include an output part configured to output a message notifying that the heater has a breakdown in a case in which it is determined that the heater has a breakdown.

The refrigerator may further includes an additional heater configured to supply heat to the ice making cell in at least a portion of the section while the cold air supply part supplies cold air so that the bubbles dissolved in the water inside the ice making cell move from an ice-generating portion to the liquid water to generate transparent ice.

The controller may control the additional heater to be turned on when it is determined that the heater has a breakdown.

In a case in which the additional heater is turned on so that transparent ice can be generated, the controller may turn off the additional heater when the temperature sensed by the second temperature sensor reaches the first reference temperature, which is a subzero temperature, and the controller may determine that the ice generation is completed when the additional heater is turned off and the temperature sensed by the second temperature sensor reaches a second reference temperature lower than the first reference temperature after a predetermined time elapses.

The controller turns on the heater when determining that the ice generation is completed.

The controller may control one or more of a cooling power of the cold air supply part and a heating amount of the additional heater to be varied according to a mass per unit height of water in the ice making cell.

The controller can determine that the generation of the ice is completed when the temperature sensed by the second temperature sensor reaches a first reference temperature lower than <NUM> and thus the temperature sensed by the second temperature sensor reaches the second reference temperature, which is lower than the first reference temperature after turning off the second heater and then a predetermined time elapses.

The controller may control the heating amount of the heater so that the heating amount of the heater in a case in which the cooling power of the cold air supply part is a second cooling power higher than the first cooling power is greater than the heating amount of the heater in a case in which the cooling power of the cold air supply part is the first cooling power during the ice making process.

The controller may control the heating amount of the heater so that the heating amount of the heater in a case in which the target temperature of a storage chamber is a second temperature lower than the first temperature is greater than the heating amount of the heater in a case in which the target temperature of the storage chamber is the first temperature.

The controller may control the heating amount of the heater so that the heating amount of the heater in a case in which the door opening time is the second time longer than the first time is smaller than the heating amount of the heater in a case in which the door opening time is the first time during the ice making process.

The controller may control the heating amount of the heater so that the heating amount of the heater in a case in which the turn-on time of the defrost heater operating for defrost is the second time longer than the first heater is smaller than the heating amount of the heater in a case in which the turn-on time of the defrost heater is the first time.

The refrigerator may further include a pusher having a length formed in a vertical direction of the ice making cell larger than a length formed in a horizontal direction of the ice making cell so that ice is easily separated from the first tray.

The controller can control so that the end of the pusher moves from a first point positioned outside the ice making cell to a second point positioned inside the ice making cell before the second tray moves to the ice separation position in a forward direction.

Meanwhile, a method for controlling the refrigerator according to the invention includes, when it is determined that the ice making is completed, turning on a heater for ice making; controlling to turn off the heater when the temperature sensed by the temperature sensor for sensing the temperature of the ice making cell reaches the first turn-off reference temperature after the first reference time elapses in a state in which the heater is turned on by the controller; and moving the second tray to an ice separation position after the heater is turned off.

A refrigerator according to the invention includes a storage chamber configured to store food; a cold air supply part configured to supply cold air to the storage chamber; a tray configured to form an ice making cell being a space in which water is phase-changed into ice by the cold air; a temperature sensor configured to sense the temperature of water or ice in the ice making cell; a heater configured to provide heat to the tray; and a controller configured to control the heater. When the ice making is completed, the controller controls the heater to be turned on so that ice can be easily separated from the tray, and the controller may control to turn off the heater, when the temperature sensed by the temperature sensor reaches the first turn-off reference temperature greater than <NUM> after a first reference time elapses in a state in which the heater is turned on.

The tray may include a first tray forming a portion of the ice making cell and a second tray forming another portion of the ice making cell.

The second tray may be connected to a driver to be in contact with the first tray during an ice making process and to be spaced apart from the first tray during an ice separation process.

The controller may control the cold air supply part to supply cold air to the ice making cell after moving the second tray to the ice making position after the water supply of the ice making cell is completed. The controller may control the second tray to move to an ice separation position in a forward direction and then in a reverse direction to take out ice from the ice making cell after the ice generation is completed in the ice making cell. The controller may start water supply after the second tray is moved to a water supply position in a reverse direction after the ice separation is completed.

The refrigerator may further include a pusher having a length formed in a vertical direction of the ice making cell larger than a length formed in a horizontal direction of the ice making cell in order to easily separate ice from the first tray. The controller may control so that the end of the pusher moves from a first point positioned outside the ice making cell to a second point positioned inside the ice making cell before the second tray moves to the ice separation position in a forward direction.

According to the proposed invention, it is possible to determine the breakdown of the ice separation heater based on whether the temperature sensed by the temperature sensor mounted on the upper tray reaches the temperature for breakdown determination during a reference time.

In addition, by outputting a breakdown notification in response to a breakdown of the ice separation heater, maintenance and repair thereof may be facilitated.

In addition, by turning on the transparent ice heater in response to a breakdown of the ice separation heater, it is possible to smoothly separate ice, prevent damage to the upper pusher, and secure reliability of each operation part.

In addition, there is provided a refrigerator which is capable of applying an optimum heating amount by varying the heating amount for ice separation according to the degree of cooling of the ice maker, and a method for controlling the same.

<FIG> is a front view of a refrigerator according to an embodiment.

Referring to <FIG>, a refrigerator according to an embodiment may include a cabinet <NUM> including a storage chamber and a door that opens and closes the storage chamber.

The storage chamber may include a refrigerating compartment <NUM> and a freezing compartment <NUM>. The refrigerating compartment <NUM> is disposed at an upper side, and the freezing compartment <NUM> is disposed at a lower side. Each of the storage chamber may be opened and closed individually by each door. For another example, the freezing compartment may be disposed at the upper side and the refrigerating compartment may be disposed at the lower side. Alternatively, the freezing compartment may be disposed at one side of left and right sides, and the refrigerating compartment may be disposed at the other side.

The freezing compartment <NUM> may be divided into an upper space and a lower space, and a drawer <NUM> capable of being withdrawn from and inserted into the lower space may be provided in the lower space.

The door may include a plurality of doors <NUM>, <NUM>, <NUM> for opening and closing the refrigerating compartment <NUM> and the freezing compartment <NUM>. The plurality of doors <NUM>, <NUM>, and <NUM> may include some or all of the doors <NUM> and <NUM> for opening and closing the storage chamber in a rotatable manner and the door <NUM> for opening and closing the storage chamber in a sliding manner. The freezing compartment <NUM> may be provided to be separated into two spaces even though the freezing compartment <NUM> is opened and closed by one door <NUM>.

In this embodiment, the freezing compartment <NUM> may be referred to as a first storage chamber, and the refrigerating compartment <NUM> may be referred to as a second storage chamber.

The freezing compartment <NUM> may be provided with an ice maker <NUM> capable of making ice. The ice maker <NUM> may be disposed, for example, in an upper space of the freezing compartment <NUM>.

An ice bin <NUM> in which the ice made by the ice maker <NUM> falls to be stored may be disposed below the ice maker <NUM>. A user may take out the ice bin <NUM> from the freezing compartment <NUM> to use the ice stored in the ice bin <NUM>.

The ice bin <NUM> may be mounted on an upper side of a horizontal wall that partitions an upper space and a lower space of the freezing compartment <NUM> from each other.

Although not shown, the cabinet <NUM> is provided with a duct supplying cold air to the ice maker <NUM>. The duct guides the cold air heat-exchanged with a refrigerant flowing through the evaporator to the ice maker <NUM>. For example, the duct may be disposed behind the cabinet <NUM> to discharge the cold air toward a front side of the cabinet <NUM>. The ice maker <NUM> may be disposed at a front side of the duct. Although not limited, a discharge hole of the duct may be provided in one or more of a rear wall and an upper wall of the freezing compartment <NUM>.

Although the above-described ice maker <NUM> is provided in the freezing compartment <NUM>, a space in which the ice maker <NUM> is disposed is not limited to the freezing compartment <NUM>. For example, the ice maker <NUM> may be disposed in various spaces as long as the ice maker <NUM> receives the cold air.

<FIG> is a perspective view of an ice maker according to an embodiment. <FIG> is a perspective view illustrating a state in which a bracket is removed from the ice maker of <FIG>. <FIG> is an exploded perspective view of the ice maker according to an embodiment. <FIG> is a cross-sectional view taken along line A-A of <FIG> for illustrating a second temperature sensor installed in the ice maker according to an embodiment of the present invention.

<FIG> is a longitudinal cross-sectional view of an ice maker when a second tray is positioned at a water supply position according to an embodiment of the present invention.

Referring to <FIG>, each component of the ice maker <NUM> may be provided inside or outside the bracket <NUM>, and thus, the ice maker <NUM> may constitute one assembly.

The bracket <NUM> may be installed at, for example, the upper wall of the freezing compartment <NUM>. A water supply part <NUM> may be installed above the inner surface of the bracket <NUM>. The water supply part <NUM> is provided with openings at the upper and lower sides, respectively, so that water supplied to the upper side of the water supply part <NUM> may be guided to the lower side of the water supply part <NUM>. The upper opening of the water supply part <NUM> is larger than the lower opening, and thus a discharge range of water guided downward through the water supply part <NUM> may be limited. A water supply pipe through which water is supplied may be installed above the water supply part <NUM>. The water supplied to the water supply part <NUM> may move downward. The water supply part <NUM> may prevent the water discharged from the water supply pipe from dropping from a high position, thereby preventing the water from splashing. Since the water supply part <NUM> is disposed below the water supply pipe, the water may be guided downward without splashing up to the water supply part <NUM>, and an amount of splashing water may be reduced even if the water moves downward due to the lowered height.

The ice maker <NUM> may include an ice making cell <NUM> in which water is phase-changed into ice by the cold air.

The ice maker <NUM> may include a first tray <NUM> forming at least a portion of a wall for providing the ice making cell 320a, and a second tray <NUM> forming at least another portion of the wall for providing the ice making cell 320a. Although not limited, the ice making cell 320a may include a first cell 320b and a second cell 320c. The first tray <NUM> may define the first cell 320b, and the second tray <NUM> may define the second cell 320c.

The second tray <NUM> may be disposed to be relatively movable with respect to the first tray <NUM>. The second tray <NUM> may linearly rotate or rotate. Hereinafter, the rotation of the second tray <NUM> will be described as an example.

For example, in an ice making process, the second tray <NUM> may move with respect to the first tray <NUM> so that the first tray <NUM> and the second tray <NUM> contact each other. When the first tray <NUM> and the second tray <NUM> contact each other, the complete ice making cell 320a may be defined. On the other hand, the second tray <NUM> may move with respect to the first tray <NUM> during the ice making process after the ice making is completed, and the second tray <NUM> may be spaced apart from the first tray <NUM>.

In this embodiment, the first tray <NUM> and the second tray <NUM> may be arranged in a vertical direction in a state in which the ice making cell 320a is formed. Accordingly, the first tray <NUM> may be referred to as an upper tray, and the second tray <NUM> may be referred to as a lower tray.

A plurality of ice making cells 320a may be defined by the first tray <NUM> and the second tray <NUM>. Hereinafter, in <FIG>, three ice making cells 320a are provided as an example.

When water is cooled by cold air while water is supplied to the ice making cell 320a, ice having the same or similar shape as that of the ice making cell 320a may be made. In this embodiment, for example, the ice making cell 320a may be provided in a spherical shape or a shape similar to a spherical shape. The ice making cell 320a may have a rectangular parallelepiped shape or a polygonal shape. In this case, the first cell 320b may have a hemispherical shape or a shape similar to that of a hemisphere. In addition, the second cell 320c may be formed in a hemispherical shape or a shape similar to that of a hemisphere.

The ice maker <NUM> may further includes a first tray case <NUM> coupled to the first tray <NUM>.

For example, the first tray case <NUM> may be coupled to an upper side of the first tray <NUM>. The first tray case <NUM> and the bracket <NUM> may be integrally provided or coupled to each other with each other after being manufactured in separate configurations.

The ice maker <NUM> may further include a first heater case <NUM>. An ice separation heater <NUM> (or a first heater) may be installed in the first heater case <NUM>. The heater case <NUM> may be integrally formed with the first tray case <NUM> or may be separately formed. The ice separation heater <NUM> may be disposed at a position adjacent to the first tray <NUM>. The ice separation heater <NUM> may be, for example, a wire type heater. For example, the ice separation heater <NUM> may be installed to contact the first tray <NUM> or may be disposed at a position spaced a predetermined distance from the first tray <NUM>. In some case, the ice separation heater <NUM> may supply heat to the first tray <NUM>, and the heat supplied to the first tray <NUM> may be transferred to the ice making cell 320a.

The ice maker <NUM> may further include a first tray cover <NUM> positioned below the first tray <NUM>. The first tray cover <NUM> has an opening formed to correspond to the shape of the ice making cell 320a of the first tray <NUM> and thus may be coupled to the lower surface of the first tray <NUM>.

The first tray case <NUM> may be provided with a guide slot <NUM> inclined at an upper side and vertically extending at a lower side. The guide slot <NUM> may be provided in a member extending upward from the first tray case <NUM>. A guide protrusion <NUM> of the first pusher <NUM> to be described later may be inserted into the guide slot <NUM>. Thus, the guide protrusion <NUM> may be guided along the guide slot <NUM>.

The first pusher <NUM> may include at least one extension portion <NUM>. For example, the first pusher <NUM> may include an extension portion <NUM> provided with the same number as the number of ice making cells 320a, but is not limited thereto. The extension portion <NUM> may push out the ice disposed in the ice making cell 320a during the ice separation process. For example, the extension portion <NUM> may be inserted into the ice making cell 320a through the first tray case <NUM>. Therefore, the first tray case <NUM> may be provided with a hole <NUM> through which a portion of the first pusher <NUM> passes. The guide protrusion <NUM> of the first pusher <NUM> may be coupled to a pusher link <NUM>. In this case, the guide protrusion <NUM> may be coupled to the pusher link <NUM> so as to be rotatable. Therefore, when the pusher link <NUM> moves, the first pusher <NUM> may also move along the guide slot <NUM>.

The ice maker <NUM> may further includes a second tray case <NUM> coupled to the second tray <NUM>. The second tray case <NUM> may support the second tray <NUM> at a lower side of the second tray <NUM>. For example, at least a portion of the wall defining a second cell 320c of the second tray <NUM> may be supported by the second tray case <NUM>.

A spring <NUM> may be connected to one side of the second tray case <NUM>. The spring <NUM> may provide elastic force to the second tray case <NUM> to maintain a state in which the second tray <NUM> contacts the first tray <NUM>.

The ice maker <NUM> may further include a second tray cover <NUM>.

The second tray <NUM> may include a circumferential wall <NUM> surrounding a portion of the first tray <NUM> in a state of contacting the first tray <NUM>. The second tray cover <NUM> may cover at least a portion of the circumferential wall <NUM>.

The ice maker <NUM> may further include a second heater case <NUM>. A transparent ice heater <NUM> (or second heater) may be installed in the second heater case <NUM>.

The transparent ice heater <NUM> will be described in detail.

The controller <NUM> according to this embodiment may control the transparent ice heater <NUM> so that heat is supplied to the ice making cell 320a in at least partial section while cold air is supplied to the ice making cell 320a to make the transparent ice.

An ice making rate may be delayed so that bubbles dissolved in water within the ice making cell 320a may move from a portion at which ice is made toward liquid water by the heat of the transparent ice heater <NUM>, thereby making transparent ice in the ice maker <NUM>. That is, the bubbles dissolved in water may be induced to escape to the outside of the ice making cell 320a or to be collected into a predetermined position in the ice making cell 320a.

When a cold air supply part <NUM> to be described later supplies cold air to the ice making cell 320a, if the ice making rate is high, the bubbles dissolved in the water inside the ice making cell 320a may be frozen without moving from the portion at which the ice is made to the liquid water, and thus, transparency of the ice may be reduced.

On the contrary, when the cold air supply part <NUM> supplies the cold air to the ice making cell 320a, if the ice making rate is low, the above limitation may be solved to increase in transparency of the ice. However, there is a limitation in which a making time increases.

Accordingly, the transparent ice heater <NUM> may be disposed at one side of the ice making cell 320a so that the heater locally supplies heat to the ice making cell 320a, thereby increasing in transparency of the made ice while reducing the ice making time.

When the transparent ice heater <NUM> is disposed on one side of the ice making cell 320a, the transparent ice heater <NUM> may be made of a material having thermal conductivity less than that of the metal to prevent heat of the transparent ice heater <NUM> from being easily transferred to the other side of the ice making cell 320a.

At least one of the first tray <NUM> and the second tray <NUM> may be a resin including plastic so that the ice attached to the trays <NUM> and <NUM> is separated well during the ice separation process.

At least one of the first tray <NUM> and the second tray <NUM> may be made of flexible material or soft material so that the tray deformed by the pushers <NUM> and <NUM> can be easily restored to the original shape thereof during the ice separation process.

The transparent ice heater <NUM> may be disposed at a position adjacent to the second tray <NUM>. The transparent ice heater <NUM> may be a wire type heater, as an example. As an example, the transparent ice heater <NUM> may be installed to contact the second tray <NUM> or may be disposed at a position spaced apart from the second tray <NUM> by a predetermined distance.

As another example, the second heater case <NUM> may not be separately provided, and the transparent ice heater <NUM> may be installed in the second tray case <NUM>.

In some cases, the transparent ice heater <NUM> may supply heat to the second tray <NUM>, and the heat supplied to the second tray <NUM> may be transferred to the ice making cell 320a.

The ice maker <NUM> may further include a driver <NUM> that provides driving force. The second tray <NUM> may relatively move with respect to the first tray <NUM> by receiving the driving force of the driver <NUM>.

A through-hole <NUM> may be defined in an extension part <NUM> extending downward in one side of the first tray case <NUM>. A through-hole <NUM> may be defined in the extension part <NUM> extending in one side of the second tray case <NUM>. At least a portion of the through-hole <NUM> may be disposed at a position higher than a horizontal line passing through a center of the ice making cell 320a. The ice maker <NUM> may further include a shaft <NUM> that passes through the through-holes <NUM> and <NUM> together.

A rotation arm <NUM> may be provided at each of both ends of the shaft <NUM>. The shaft <NUM> may rotate by receiving rotational force from the driver <NUM>. One end of the rotation arm <NUM> may be connected to one end of the spring <NUM>, and thus, a position of the rotation arm <NUM> may move to an initial value by restoring force when the spring <NUM> is tensioned.

The driver <NUM> may include a motor and a plurality of gears.

A full ice detection lever <NUM> may be connected to the driver <NUM>. The full ice detection lever <NUM> may also rotate by the rotational force provided by the driver <NUM>.

The full ice detection lever <NUM> may have a '<IMG>' shape as a whole. For example, the full ice detection lever <NUM> may include a first portion <NUM> and a pair of second portions <NUM> extending in a direction crossing the first portion <NUM> at both ends of the first portion <NUM>. One of the pair of second portions <NUM> may be coupled to the driver <NUM>, and the other may be coupled to the bracket <NUM> or the first tray case <NUM>. The full ice detection lever <NUM> may rotate to detect ice stored in the ice bin <NUM>.

The driver <NUM> may further include a cam that rotates by the rotational power of the motor.

The ice maker <NUM> may further include a sensor that senses the rotation of the cam.

For example, the cam is provided with a magnet, and the sensor may be a hall sensor detecting magnetism of the magnet during the rotation of the cam. The sensor may output first and second signals that are different outputs according to whether the sensor senses a magnet. One of the first signal and the second signal may be a high signal, and the other may be a low signal.

The controller <NUM> to be described later may determine a position of the second tray <NUM> based on the type and pattern of the signal outputted from the sensor. That is, since the second tray <NUM> and the cam rotate by the motor, the position of the second tray <NUM> may be indirectly determined based on a detection signal of the magnet provided in the cam.

For example, a water supply position, an ice making position, and an ice separation position, which will be described later, may be distinguished and determined based on the signals outputted from the sensor.

The ice maker <NUM> may further include a second pusher <NUM>. The second pusher <NUM> may be installed, for example, on the bracket <NUM>. The second pusher <NUM> may include at least one extension portion <NUM>. For example, the second pusher <NUM> may include an extension portion <NUM> provided with the same number as the number of ice making cells 320a, but is not limited thereto. The extension portion <NUM> may push out the ice disposed in the ice making cell 320a. For example, the extension portion <NUM> may pass through the second tray case <NUM> to contact the second tray <NUM> defining the ice making cell 320a and then press the contacting second tray <NUM>. Therefore, the second tray case <NUM> may include a hole <NUM> through which a portion of the second pusher <NUM> passes.

The first tray case <NUM> may be rotatably coupled to the second tray case <NUM> with respect to the second tray case <NUM> and then be disposed to change in angle about the shaft <NUM>.

In this embodiment, the second tray <NUM> may be made of a non-metal material. For example, when the second tray <NUM> is pressed by the second pusher <NUM>, the second tray <NUM> may be made of a flexible or soft material which is deformable. Although not limited, the second tray <NUM> may be made of, for example, a silicon material.

Therefore, while the second tray <NUM> is deformed while the second tray <NUM> is pressed by the second pusher <NUM>, pressing force of the second pusher <NUM> may be transmitted to ice. The ice and the second tray <NUM> may be separated from each other by the pressing force of the second pusher <NUM>.

When the second tray <NUM> is made of the non-metal material and the flexible or soft material, the coupling force or attaching force between the ice and the second tray <NUM> may be reduced, and thus, the ice may be easily separated from the second tray <NUM>.

Also, if the second tray <NUM> is made of the non-metallic material and the flexible or soft material, after the shape of the second tray <NUM> is deformed by the second pusher <NUM>, when the pressing force of the second pusher <NUM> is removed, the second tray <NUM> may be easily restored to its original shape.

On the other hand, the first tray <NUM> may be made of a metal material. In this case, since the coupling force or the attaching force between the first tray <NUM> and the ice is strong, the ice maker <NUM> according to this embodiment may include at least one of the ice separation heater <NUM> or the first pusher <NUM>.

For another example, the first tray <NUM> may be made of a non-metallic material. When the first tray <NUM> is made of the non-metallic material, the ice maker <NUM> may include only one of the ice separation heater <NUM> and the first pusher <NUM>.

Alternatively, the ice maker <NUM> may not include the ice separation heater <NUM> and the first pusher <NUM>. Although not limited, the first tray <NUM> may be made of, for example, a silicon material.

That is, the first tray <NUM> and the second tray <NUM> may be made of the same material. When the first tray <NUM> and the second tray <NUM> are made of the same material, the first tray <NUM> and the second tray <NUM> may have different hardness to maintain sealing performance at the contact portion between the first tray <NUM> and the second tray <NUM>.

In this embodiment, since the second tray <NUM> is pressed by the second pusher <NUM> to be deformed, the second tray <NUM> may have hardness less than that of the first tray <NUM> to facilitate the deformation of the second tray <NUM>.

Referring to <FIG>, the ice maker <NUM> may further include a second temperature sensor <NUM> (or tray temperature sensor) to sense a temperature of the ice making cell 320a. The second temperature sensor <NUM> may sense a temperature of water or ice of the ice making cell 320a.

The second temperature sensor <NUM> may be disposed adjacent to the first tray <NUM> to sense the temperature of the first tray <NUM>, thereby indirectly determining the water temperature or the ice temperature of the ice making cell 320a. In this embodiment, the water temperature or the ice temperature of the ice making cell 320a may be referred to as an internal temperature of the ice making cell 320a.

The second temperature sensor <NUM> may be installed in the first tray case <NUM>. In this case, the second temperature sensor <NUM> may contact the first tray <NUM> or may be spaced apart from the first tray <NUM> by a predetermined distance. Alternatively, the second temperature sensor <NUM> may be installed on the first tray <NUM> to contact the first tray <NUM>.

Of course, in a case in which the second temperature sensor <NUM> is disposed to pass through the first tray <NUM>, the second temperature sensor <NUM> may directly sense the temperature of the water or the temperature of ice of the ice making cell 320a.

Meanwhile, a portion of the ice separation heater <NUM> may be positioned higher than the second temperature sensor <NUM> and may be spaced apart from the second temperature sensor <NUM>. An electric wire <NUM> connected to the second temperature sensor <NUM> may be guided above the first tray case <NUM>.

Referring to <FIG>, the ice maker <NUM> according to this embodiment may be designed so that the positions of the second tray <NUM> are different from each other at a water supply position and an ice making position.

For example, the second tray <NUM> may include a second cell wall <NUM> defining a second cell 320c of the ice making cells 320a and a peripheral wall <NUM> extending along an outer edge of the second cell wall <NUM>.

The second cell wall <NUM> may include an upper surface 381a. In this specification, the upper surface 381a of the second cell wall <NUM> may be referred to as the upper surface 381a of the second tray <NUM>.

The upper surface 381a of the second cell wall <NUM> may be positioned lower than the upper end portion of the peripheral wall <NUM>.

The first tray <NUM> may include a first cell wall 321a defining a first cell 320b of the ice making cells 320a. The first cell wall 321a may include a straight portion 321b and a curved portion 321c. The curved portion 321c may be formed in an arc shape having a center of the shaft <NUM> as a radius of curvature. Accordingly, the peripheral wall <NUM> may also include a straight portion and a curved portion corresponding to the straight portion 321b and the curved portion 321c.

The first cell wall 321a may include a lower surface 321d. In the present specification, the lower surface 321b of the first cell wall 321a may be referred to be the lower surface 321b of the first tray <NUM>. The lower surface 321d of the first cell wall 321a may contact the upper surface 381a of the second cell wall 381a.

For example, in the water supply position as illustrated in <FIG>, at least a portion of the upper surface 381a of the second cell wall <NUM> and the lower surface 321d of the first cell wall 321a may be spaced apart from each other.

In <FIG>, as an example, it is illustrated that all the upper surface 381a of the second cell wall <NUM> and the lower surface 321d of the first cell wall 321a are spaced apart from each other.

Accordingly, the upper surface 381a of the second cell wall <NUM> may be inclined to form a predetermined angle with the lower surface 321d of the first cell wall 321a.

Although not limited, at the water supply position, the lower surface 321d of the first cell wall 321a may be maintained to be substantially horizontal, and the upper surface 381a of the second cell wall <NUM> may be disposed to be inclined with respect to the lower surface 321d of the first cell wall 321a under the first cell wall 321a.

In the state illustrated in <FIG>, the peripheral wall <NUM> may surround the first cell wall 321a. In addition, the upper end portion of the circumferential wall <NUM> may be positioned higher than the lower surface 321d of the first cell wall 321a.

Meanwhile, in the ice making position (see <FIG>), the upper surface 381a of the second cell wall <NUM> may contact at least a portion of the lower surface 321d of the first cell wall 321a.

The angle between the upper surface 381a of the second tray <NUM> and the lower surface 321d of the first tray <NUM> at the ice making position is smaller than the angle between the upper surface 382a of the second tray <NUM> and the lower surface 321d of the first tray <NUM> at the water supply position.

In the ice making position, the upper surface 381a of the second cell wall <NUM> may contact all the lower surface 321d of the first cell wall 321a. In the ice making position, an upper surface 381a of the second cell wall <NUM> and a lower surface 321d of the first cell wall 321a may be disposed to be substantially horizontal.

In this embodiment, the reason why the water supply position and the ice making position of the second tray <NUM> are different is that in a case in which the ice maker <NUM> includes a plurality of ice making cells 320a, water is to be uniformly distributed to the plurality of ice making cells 320a without forming a water passage for communication between respective ice making cells 320a in the first tray <NUM> and/or the second tray <NUM>.

If the ice maker <NUM> includes the plurality of ice making cells 320a when a water passage is formed in the first tray <NUM> and/or the second tray <NUM>, the water supplied to the ice maker <NUM> is distributed to the plurality of ice making cells 320a along the water passage.

However, in a state in which the water is distributed to the plurality of ice making cells 320a, water exists also in the water passage, and when ice is generated in this state, ice generated in the ice making cell 320a is connected by ice generated in the water passage portion.

In this case, there is a possibility that the ices will stick to each other even after the ice separation is completed, and even if the ice is separated from each other, some of the plurality of the ices contains ice generated in the water passage portion, so there is a problem that the shape of the ice is different from the shape of the ice in the ice making cell.

However, as in this embodiment, in a state in which the second tray <NUM> is spaced apart from the first tray <NUM> at the water supply position, the water dropped to the second tray <NUM> may be uniformly distributed to the plurality of second cells 320c of the second tray <NUM>.

For example, the first tray <NUM> may include a communication hole 321e. In a case in which the first tray <NUM> includes one first cell 320b, the first tray <NUM> may include one communication hole 321e.

When the first tray <NUM> includes a plurality of first cells 320b, the first tray <NUM> may include a plurality of communication holes 321e. The water supply part <NUM> may supply water to one communication hole 321e among the plurality of communication holes 321e. In this case, water supplied through the one communication hole 321e drops into the second tray <NUM> after passing through the first tray <NUM>.

During the water supply process, water may drop into any one second cell 320c of the plurality of second cells 320c of the second tray <NUM>. Water supplied to one second cell 320c overflows from one second cell 320c.

In this embodiment, since the upper surface 381a of the second tray <NUM> is spaced apart from the lower surface 321d of the first tray <NUM>, the water overflowing from the one second cell 320c moves to another adjacent second cell 320c along the upper surface 381a of the second tray <NUM>. Accordingly, water may be fully filled in the plurality of second cells 320c of the second tray <NUM>.

In addition, in a state in which the water supply is completed, a portion of the water supplied can be fully filled in the second cell 320c, and another portion of the water supplied can be filled in the space between the first tray <NUM> and the second tray <NUM>.

In the water supply position, according to the volume of the ice making cell 320a, water, when water supply is completed may be positioned only in the space between the first tray <NUM> and the second tray <NUM> or may be positioned in the space between the first tray <NUM> and the second trays <NUM> and also in the first tray <NUM> (see <FIG>).

When the second tray <NUM> moves from the water supply position to the ice making position, water in the space between the first tray <NUM> and the second tray <NUM> can be uniformly distributed to the plurality of first cells 320b.

Meanwhile, when a water passage is formed in the first tray <NUM> and/or the second tray <NUM>, ice generated in the ice making cell 320a is also generated in the water passage portion.

In this case, in order to generate transparent ice, when the controller of the refrigerator controls so that at least one of the cooling power of the cold air supply part <NUM> and the heating amount of the transparent ice heater <NUM> are varied according to the mass per unit height of water in the ice making cell 320a, at least one of the cooling power of the cold air supply part <NUM> and the heating amount of the transparent ice heater <NUM> in the portion where the water passage is formed is controlled to be rapidly varied several times or more.

This is because the mass per unit height of water rapidly increases several times or more in the portion where the water passage is formed. In this case, reliability problems of parts may occur, and expensive parts in which width between the maximum output and minimum output is large can be used, which may be disadvantageous in terms of power consumption and cost of the parts. As a result, the present invention may require a technique related to the above-described ice making position to also generate transparent ice.

<FIG> is a block diagram illustrating a control of a refrigerator according to an embodiment.

Referring to <FIG>, the refrigerator according to this embodiment may include a cold air supply part <NUM> supplying a cold air to the freezing compartment <NUM> (or the ice making cell). The cold air supply part <NUM> may supply cold air to the freezing compartment <NUM> using a refrigerant cycle.

For example, the cold air supply part <NUM> may include a compressor compressing the refrigerant. A temperature of the cold air supplied to the freezing compartment <NUM> may vary according to the output (or frequency) of the compressor. Alternatively, the cold air supply part <NUM> may include a fan blowing air to an evaporator. An amount of cold air supplied to the freezing compartment <NUM> may vary according to the output (or rotation rate) of the fan. Alternatively, the cold air supply part <NUM> may include a refrigerant valve controlling an amount of refrigerant flowing through the refrigerant cycle.

An amount of refrigerant flowing through the refrigerant cycle may vary by adjusting an opening degree by the refrigerant valve, and thus, the temperature of the cold air supplied to the freezing compartment <NUM> may vary.

Therefore, in this embodiment, the cold air supply part <NUM> may include one or more of the compressor, the fan, and the refrigerant valve.

The refrigerator according to this embodiment may further include a controller <NUM> which controls the cold air supply part <NUM>. In addition, the refrigerator may further include a water supply valve <NUM> for controlling an amount of water supplied through the water supply part <NUM>.

In addition, the refrigerator may further include an input part <NUM> configured to set and change a target temperature of a storage chamber in which the ice maker <NUM> is provided. For example, target temperatures of the refrigerating compartment <NUM> and the freezing compartment <NUM> may be set and changed, respectively, through the input part <NUM>.

The refrigerator may further include an output part <NUM> through which information of the ice maker <NUM> is output. As a example, the input part <NUM> and the output part <NUM> may be separately formed in the refrigerator, and, as another example, one component may serve as the input part <NUM> and the output part <NUM>.

The refrigerator may further include a door opening/closing detector <NUM> for detecting opening/closing of a door of a storage chamber (for example, the freezing compartment <NUM>) in which the ice maker <NUM> is installed.

The controller <NUM> can control some or all the ice separation heater <NUM>, the transparent ice heater <NUM>, the driver <NUM>, the cold air supply part <NUM>, a water supply valve <NUM>, an input part <NUM>, and an output part <NUM>.

When the door opening/closing detector <NUM> detects the opening/closing of the door (a state in which the door is open and closed), the controller <NUM> may determine whether the cooling power of the cold air supply part <NUM> is varied based on the temperature detected by the first temperature sensor <NUM>.

When the door opening/closing detector <NUM> detects the opening/closing of the door, the controller <NUM> may determine whether the output of the transparent ice heater <NUM> is varied based on the temperature detected by the second temperature sensor <NUM>.

The controller <NUM> may determine whether to change the output of the ice separation heater <NUM> based on the temperature sensed by the second temperature sensor <NUM>.

Meanwhile, in this embodiment, in a case in which the ice maker <NUM> includes both the ice separation heater <NUM> and the transparent ice heater <NUM>, the output of the ice separation heater <NUM> and the output of the transparent ice heater <NUM> may be different. In a case in which the outputs of the ice separation heater <NUM> and the transparent ice-heating heater <NUM> are different, the output terminal of the ice separation heater <NUM> and the output terminal of the transparent ice heater <NUM> may be formed in different shapes and thus incorrect connection of the two output terminals can be prevented.

Although not limited, the output of the ice separation heater <NUM> may be set to be greater than the output of the transparent ice heater <NUM>. Accordingly, ice can be quickly separated from the first tray <NUM> by the ice separation heater <NUM>.

The refrigerator may further include a first temperature sensor <NUM> (or a temperature sensor in the refrigerator) for sensing the temperature of the freezing compartment <NUM>.

The controller <NUM> may control the cold air supply part <NUM> based on the temperature sensed by the first temperature sensor <NUM>. The controller <NUM> may determine whether ice making is completed based on the temperature sensed by the second temperature sensor <NUM>.

<FIG> is a flowchart for explaining a process of making ice in the ice maker according to an embodiment, and <FIG> is a flow chart for explaining a process of determining a breakdown of the ice separation heater according to an embodiment of the present invention.

<FIG> is a view illustrating a state in which the water supply is completed at a water supply position, <FIG> is a view illustrating a state in which ice is generated at the ice making position, <FIG> is a view illustrating a state in which the second tray is separated from the first tray in an ice separation process, and <FIG> is a view illustrating a state in which a second tray has been moved to an ice separation position during an ice separation process.

Referring to <FIG>, in order to generate ice in the ice maker <NUM>, the controller <NUM> moves the second tray <NUM> to a water supply position (S1).

In the present specification, a direction in which the second tray <NUM> moves from the ice making position of <FIG> to the ice separation position of <FIG> may be referred to as a forward movement (or forward rotation). On the other hand, a direction moving from the ice separation position of <FIG> to the water supply position of <FIG> may be referred to as a reverse movement (or reverse rotation).

The movement of the water supply position of the second tray <NUM> is sensed by a sensor, and when it is sensed that the second tray <NUM> has moved to the water supply position, the controller <NUM> stops the driver <NUM>.

Water supply is started in a state in which the second tray <NUM> is moved to the water supply position (S2). For water supply, the controller <NUM> turns on the water supply valve <NUM>, and when it is determined that a set amount of water has been supplied, the controller <NUM> may turn off the water supply valve <NUM>.

For example, in the process of supplying water, when a pulse is output from a flow sensor (not illustrated) and the output pulse reaches a reference pulse, it may be determined that a set amount of water has been supplied.

After the water supply is completed, the controller <NUM> controls the driver <NUM> to move the second tray <NUM> to the ice making position (S3). For example, the controller <NUM> may control the driver <NUM> so that the second tray <NUM> moves from a water supply position in a reverse direction.

When the second tray <NUM> is moved in the reverse direction, the upper surface 381a of the second tray <NUM> becomes close to the lower surface 321e of the first tray <NUM>. Then, the water between the upper surface 381a of the second tray <NUM> and the lower surface 321e of the first tray <NUM> is divided and distributed into each of the plurality of second cells 320c. When the upper surface 381a of the second tray <NUM> and the lower surface 321e of the first tray <NUM> are completely in close contact, the first cell 320b is filled with water.

The movement of the ice making position of the second tray <NUM> is detected by a sensor, and when it is sensed that the second tray <NUM> has moved to the ice making position, the controller <NUM> stops the driver <NUM>.

The ice making starts in a state in which the second tray <NUM> is moved to the ice making position (S4). For example, when the second tray <NUM> reaches the ice making position, the ice making may start. Alternatively, when the second tray <NUM> reaches the ice making position and the water supply time elapses, the ice making may start.

When the ice making starts, the controller <NUM> may control the cold air supply part <NUM> so that cold air is supplied to the ice making cell 320a.

After the ice making starts, the controller <NUM> may control the transparent ice heater <NUM> to be turned on in at least a portion of the section while the cold air supply part <NUM> supplies cold air to the ice making cell 320a (S5).

In a case in which the transparent ice heater <NUM> is turned on, since heat from the transparent ice heater <NUM> is transferred to the ice making cell 320a, the generation rate of the ice in the ice making cell 320a may be delayed.

As in this embodiment, by the heat of the transparent ice heater <NUM>, by delaying the generation rate of the ice so that bubbles dissolved in the water inside the ice making cell 320a can move from the ice-generating portion to the liquid water, transparent ice may be generated in the ice maker <NUM>.

During the ice making process, the controller <NUM> may determine whether the turn-on condition of the transparent ice heater <NUM> is satisfied. In this embodiment, the transparent ice heater <NUM> is not turned on immediately after ice making starts, but the transparent ice heater <NUM> may be turned on when the turn-on condition of the transparent ice heater <NUM> has to be satisfied.

In general, water supplied to the ice making cell 320a may be water at room temperature or water at a temperature lower than room temperature. The temperature of the water supplied in this way is higher than the freezing point of the water. Therefore, after the water supply, when the temperature of the water decreases due to the cold air and then reaches the freezing point of the water, the water changes to ice.

In the case of this embodiment, the transparent ice heater <NUM> may not be turned on until the water phase-changes into ice.

If the transparent ice heater <NUM> is turned on before the temperature of the water supplied to the ice making cell 320a reaches the freezing point, the speed at which the water temperature reaches the freezing point by the heat of the transparent ice heater <NUM> becomes slow, and thus, as a result, the start of ice generation is delayed.

The transparency of ice may vary depending on the presence or absence of bubbles in the portion where ice is generated, wherein when heat is supplied to the ice making cell 320a before ice is generated, it can be seen that the transparent ice heater <NUM> operates regardless of the transparency of ice.

Therefore, according to this embodiment, in a case in which the transparent ice heater <NUM> is turned on after the turn-on condition of the transparent ice heater <NUM> is satisfied, it can be prevented power from being consumed due to unnecessary operation of the transparent ice heater <NUM>.

Of course, even if the transparent ice heater <NUM> is turned on immediately after the start of ice making, the transparency is not affected, and thus the transparent ice heater <NUM> may be turned on after the start of ice making.

In this embodiment, the controller <NUM> may determine that the turn-on condition of the transparent ice heater <NUM> is satisfied when a predetermined time elapses from a set specific time point. The specific time point may be set to at least one of the time points before the transparent ice heater <NUM> is turned on. For example, the specific time point may be set as a time when the cold air supply part <NUM> starts to supply cooling power for ice making, a time when the second tray <NUM> reaches the ice making position, a time when water supply is completed, and the like.

Alternatively, the controller <NUM> may determine that the turn-on condition of the transparent ice heater <NUM> is satisfied when the temperature sensed by the second temperature sensor <NUM> reaches the turn-on reference temperature.

For example, the turn-on reference temperature may be a temperature for determining that water has started to freeze at the top side (the communication hole side) of the ice making cell 320a.

In a case in which a portion of water is frozen in the ice making cell 320a, the temperature of ice in the ice making cell 320a is the sub-zero temperature. The temperature of the first tray <NUM> may be higher than the temperature of ice in the ice making cell 320a.

Of course, although water is present in the ice making cell 320a, the temperature sensed by the second temperature sensor <NUM> may be the sub-zero temperature after the ice is started to be generated in the ice making cell 320a.

Accordingly, in order to determine that ice has started to be generated in the ice making cell 320a based on the temperature sensed by the second temperature sensor <NUM>, the turn-on reference temperature may be set to the sub-zero temperature.

That is, in a case in which the temperature sensed by the second temperature sensor <NUM> reaches the turn-on reference temperature, the turn-on reference temperature is the sub-zero temperature, so the temperature of the ice in the ice making cell 320a is the sub-zero temperature and will be lower than the turn-on reference temperature. Accordingly, it may be indirectly determined that ice is generated in the ice making cell 320a.

In this way, when the transparent ice heater <NUM> is turned on, heat from the transparent ice heater <NUM> is transferred into the ice making cell 320a.

As in this embodiment, in a case in which the second tray <NUM> is positioned under the first tray <NUM> and the transparent ice heater <NUM> is disposed to supply heat to the second tray <NUM>, ice may start to be generated from the upper side of the ice making cell 320a.

In this embodiment, since ice is generated from the upper side in the ice making cell 320a, bubbles move downward from the ice-generating portion to the liquid water in the ice making cell 320a.

Since the density of water is greater than the density of ice, water or bubbles may convect in the ice making cell 320a, and bubbles may move toward the transparent ice heater <NUM>.

In this embodiment, the mass (or volume) per unit height of water in the ice making cell 320a may be the same or different according to the shape of the ice making cell 320a. For example, in a case in which the ice making cell 320a is a rectangular parallelepiped, the mass (or volume) per unit height of water in the ice making cell 320a is the same. On the other hand, in a case in which the ice making cell 320a has a shape such as a spherical shape, an inverted triangle, or a crescent shape, the mass (or volume) per unit height of water is different.

If, assuming that the cooling power of the cold air supply part <NUM> is constant, if the heating amount of the transparent ice heater <NUM> is the same, since the mass per unit height of water is different in the ice making cell 320a, the rate at which ice is generated per unit height may vary.

For example, in a case in which the mass per unit height of water is small, the rate of ice generation is high, whereas in a case in which the mass per unit height of water is large, the rate of ice generation is slow.

As a result, the rate at which ice is generated per unit height of water may not be constant, so the transparency of ice may vary for each unit height. In particular, when the rate of generation of ice is high, bubbles cannot move from ice to water, so that the ice contains bubbles, and thus transparency may be low.

That is, the smaller the deviation in the rate at which ice is generated per unit height of water, the smaller the variation in transparency per unit height of the generated ice.

Accordingly, in this embodiment, the controller <NUM> can control that the cooling power of the cold air supply part <NUM> and/or the heating amount of the transparent ice heater <NUM> according to the mass per unit height of water of the ice making cell 320a is varied.

In the present specification, the cooling power of the cold air supply part <NUM> may include one or more of variable output of the compressor, variable output of the fan, and variable opening degree of the refrigerant valve.

In addition, in the present specification, the variable heating amount of the transparent ice heater <NUM> may mean varying the output of the transparent ice heater <NUM> or varying the duty of the transparent ice heater <NUM>.

At this time, the duty of the transparent ice heater <NUM> means a ratio of the turn-on time to the turn-on time and turn-off time of the transparent ice heater <NUM> in one cycle, or may mean a ratio of a turn-off time to a turn-on time and a turn-off time of the transparent ice heater <NUM> in one cycle.

In this specification, the reference of the unit height of water in the ice making cell 320a may be different according to a relative position between the ice making cell 320a and the transparent ice heater <NUM>.

In a case in which the output of the transparent ice heater <NUM> is constant, there are problems that the ice generation rate is different for each unit height, so that the transparency of ice varies according to the unit height and in certain sections, the rate of ice generation is too high, the ice includes bubbles, and thus the transparency thereof is lowered.

Therefore, in this embodiment, the output of the transparent ice heater <NUM> can be controlled so that the ice generation rate for each unit height is the same or similar while allowing the bubbles to move toward the water from an ice-generating portion in the ice generation process.

By controlling the output of the transparent ice heater <NUM>, the transparency of ice becomes uniform for each unit height, and bubbles are collected in the lowermost section. Therefore, when viewing ice as a whole, bubbles may be collected in the local portion of the ice and all other portions of the ice may be transparent throughout.

Even if the ice making cell 320a is not in a spherical shape, transparent ice may be generated in a case in which the output of the transparent ice heater <NUM> is varied according to the mass of the water in the ice making cell 320a for each unit height.

The heating amount of the transparent ice heater <NUM> in a case in which the mass per unit height of water is large is smaller than the heating amount of the transparent ice heater <NUM> in a case in which the mass per unit height of water is small.

For example, while maintaining the same cooling power of the cold air supply part <NUM>, the heating amount of the transparent ice heater <NUM> may be varied so as to be inversely proportional to the mass of each unit height of water.

In addition, transparent ice can be generated by varying the cooling power of the cold air supply part <NUM> according to the mass of each unit height of water.

For example, in a case in which the mass of water per unit height is large, the cooling power of the cool air supply means <NUM> may increase, and in a case in which the mass per unit height is small, the cooling power of the cold air supply part <NUM> may decrease.

For example, while maintaining a constant heating amount of the transparent ice heater <NUM>, the cooling power of the cold air supply part <NUM> may be varied in proportion to the mass per unit height of water.

Looking at the cooling power variable pattern of the cold air supply part <NUM> in the case of generating spherical ice, the cooling power of the cold air supply part <NUM> may increase from the beginning section to the intermediate section during the ice making process step by step.

The cooling power of the cold air supply part <NUM> becomes maximum in the intermediate section in which the mass of water per unit height is the minimum. From the next section of the intermediate section, the cooling power of the cold air supply part <NUM> may be reduced step by step. Alternatively, transparent ice may be generated by varying the cooling power of the cold air supply part <NUM> and the heating amount of the transparent ice heater <NUM> according to the mass of each unit height of water.

For example, the cooling power of the cold air supply part <NUM> may be varied in proportion to the mass per unit height of water, and the heating amount of the transparent ice heater <NUM> may be varied in inverse proportion to the mass per unit height of water.

As in this embodiment, in a case in which one or more of the cooling power of the cold air supply part <NUM> and the heating amount of the transparent ice heater <NUM> are controlled according to the mass of each unit height of water, the rate of ice generation per unit height of water is substantially same or may be maintained within a predetermined range.

Meanwhile, the controller <NUM> may determine whether ice making is completed based on the temperature sensed by the second temperature sensor <NUM> (S6). When it is determined that ice making is completed, the controller <NUM> may turn off the transparent ice heater <NUM> (S7).

For example, when the temperature sensed by the second temperature sensor <NUM> reaches a first reference temperature, the controller <NUM> may determine that ice making has been completed and turn off the transparent ice heater <NUM>.

At this time, in this embodiment, since the distance between the second temperature sensor <NUM> and each ice making cell 320a is different, in order to determine that ice generation has been completed in all ice making cells 320a, the controller <NUM> may start the ice separation after a determined time has elapsed from the time point when it is determined that the ice making has been completed or when the temperature sensed by the second temperature sensor <NUM> reaches a second reference temperature lower than the first reference temperature.

When the ice making is completed, in order to separate ice, the controller <NUM> operates the ice separation heater <NUM> (S8). When the ice separation heater <NUM> is turned on and operates normally, heat from the heater is transferred to the first tray <NUM> so that ice may be separated from the surface (inner surface) of the first tray <NUM>.

In addition, the heat of the ice separation heater <NUM> is transferred from the first tray <NUM> to the contact surface of the second tray <NUM>, so that the lower surface 321d of the first tray <NUM> and the upper surface 381a of the second tray <NUM> are in a state of being capable of being separated.

However, when the heat transfer amount between the cold air in the freezing compartment <NUM> and the water in the ice making cell 320a is varied, if the heating amount of the ice separation heater <NUM> is not adjusted to reflect this, there is a problem that ice separation is not smooth since the ice excessively melt or ice does not melt enough.

In this embodiment, a case in which the heat transfer amount of cold air and water increases may be, for example, a case in which the cooling power of the cold air supply part <NUM> increases, or a case in which air having a temperature lower than the temperature of the cold air in the freezing compartment <NUM> is supplied to the freezing compartment <NUM>.

On the other hand, a case in which the heat transfer amount of cold air and water is reduced may be, for example, a case in which the cooling power of the cold air supply part <NUM> is reduced, a case in which the door is opened and air having a temperature higher than the temperature of the cold air in the freezing compartment <NUM> is supplied to the freezing compartment <NUM>, a case in which food having a temperature higher than the temperature of cold air in the freezing compartment <NUM> is put into the freezing compartment <NUM>, or a state in which a defrost heater (not illustrated) for defrosting the evaporator is turned on.

For example, in a case in which the target temperature of the freezing compartment <NUM> decreases, the operating mode of the freezing compartment <NUM> is changed from the normal mode to the rapid cooling mode, the output of at least one of the compressor and the fan increases, or the opening degree of the refrigerant valve increases, the cooling power of the cold air supply part <NUM> may increases.

On the other hand, in a case in which the target temperature of the freezing compartment <NUM> increases, the operating mode of the freezing compartment <NUM> is changed from the rapid cooling mode to the normal mode, the output of at least one of the compressor and the fan is reduced, or the opening degree of the refrigerant valve is reduced, the cooling power of the cold air supply part <NUM> may be reduced.

In a case in which the heat transfer amount of the cold air and water increases, the temperature of the cold air around the ice maker <NUM> decreases, so that the rate of ice generation increases.

On the other hand, when the heat transfer amount of the cold air and water is reduced, the temperature of the cold air around the ice maker <NUM> increases, so that the rate of ice generation is slowed, and the ice making time is lengthened.

Accordingly, in this embodiment, in a case in which the heat transfer amount of cold air and water increases, the heating amount of the ice separation heater <NUM> may be controlled to increase. On the other hand, in a case in which the heat transfer amount of the cold air and water is reduced, the heating amount of the ice separation heater <NUM> may be controlled to be reduced.

As another example, the ice separation heater <NUM> may transfer heat to the first tray <NUM> with constant output.

In this case, the controller <NUM> may determine the output of the ice separation heater <NUM> in consideration of an initial condition in order to solve a problem in which ice separation is not smooth due to external factors.

The initial condition may include a cooling power of the cold air supply part <NUM>, a target temperature of the storage chamber, a door opening time, and a turn-on time of the defrost heater.

In detail, if the cooling power of the cold air supply part <NUM> is higher when the cooling power of the cold air supply part <NUM> is the second cooling power than when the cooling power of the cold air supply part <NUM> is the first cooling power during the ice making process, the controller <NUM> can control the heating amount of the ice separation heater <NUM> to be larger when the cooling power of the cold air supply part <NUM> is the second cooling power.

Since the fact that the cooling power of the cold air supply part <NUM> is high means that the heat transfer amount of cold air and water increases, so as to prevent the case in which the ice cannot be separated due to insufficient heating amount of the ice separation heater <NUM>, if the cooling power of the cold air supply part <NUM> is high, the heating amount of the ice separation heater <NUM> may be also controlled to be larger.

In addition, if the target temperature of the storage chamber set by the user is higher when the target temperature is the second temperature than when the target temperature is the first temperature, the controller <NUM> can control the heating amount of the ice separation heater <NUM> when the target temperature is the second temperature to be smaller.

This is to prevent the case in which the target temperature of the storage chamber is set higher so that the ice excessively melts by the ice separation heater <NUM>.

In addition, according to a similar principle, if the door opening time in the ice making process or the turn-on time of the defrost heater operating for defrosting is longer in the second time than in the first time, the controller <NUM> can control the heating amount of the ice separation heater <NUM> when the door opening time in the ice making process or the turn-on time of the defrost heater operating for defrosting is the second time to be smaller.

After the ice separation heater <NUM> is turned on, the controller <NUM> determines whether the turn-off reference of the ice separation heater <NUM> is satisfied (S9).

A condition in which the ice separation heater <NUM> is turned off may be a case in which the ice separation heater <NUM> is operated for a turn-off reference time (S91), or the temperature sensed by the second temperature sensor <NUM> may be equal to or greater than a turn-off reference temperature (or the first turn-off reference temperature) of the ice separation heater <NUM> (S92). The turn-off reference time may be referred to as a first reference time. In addition, in a case in which the temperature sensed by the second temperature sensor <NUM> reaches the first turn-off reference temperature during the turn-off reference time, the ice separation heater <NUM> may be turned off. For example, the first turn-off reference temperature may be a temperature at which the first tray <NUM> and ice can be separated by the ice separation heater <NUM>. Although not limited, the first turn-off reference temperature may be set as the above-zero temperature.

When the ice separation heater <NUM> satisfies the turn-off reference, the controller <NUM> turns off the ice separation heater <NUM> (S10).

After the ice separation heater <NUM> is turned off, the controller <NUM> operates the driver <NUM> so that the second tray <NUM> is moved in a forward direction for ice separation (S13).

Meanwhile, in a case in which the ice separation heater <NUM> does not satisfy the turn-off reference, it is determined whether the ice separation heater <NUM> has a breakdown (S11).

In detail, in a case in which the temperature sensed by the second temperature sensor <NUM> does not reach the turn-off reference temperature during the turn-off reference time by the ice separation heater <NUM>, the controller <NUM> may determine whether the ice separation heater <NUM> has a breakdown.

If the case of not satisfying the turn-off reference of the ice separation heater <NUM> is immediately determined as a breakdown of the ice separation heater <NUM>, there is an problem that external factors of the ice maker, such as the occurrence of door opening time or the case of turning on the defrost heater, are not considered. Therefore, it is preferable to determine whether the ice separation heater <NUM> has a breakdown separately from the turn-off reference of the ice separation heater <NUM>.

In detail, the controller <NUM> may determine whether a breakdown reference time (or a second reference time) has elapsed after the ice separation heater <NUM> is turned on (S111).

Until the breakdown reference time has elapsed, in a case in which the turn-off reference of the ice separation heater <NUM> is not satisfied, the controller <NUM> may determine that the ice separation heater <NUM> has a breakdown.

For example, in a case in which the ice separation heater <NUM> is turned on and the second reference time has passed but the temperature sensed by the second temperature sensor <NUM> does not reach the first turn-off reference temperature, the controller <NUM> may determine that the ice separation heater <NUM> has a breakdown.

The second reference time may be longer than the first reference time, and the first reference time and the second reference time can be varied according to a degree to which a heat transfer amount between the cold air in the freezing compartment <NUM> and the water in the ice making cell 320a is varied.

In detail, in this embodiment, in a case in which the heat transfer amount of cold air and water increases, the first reference time and the second reference time may increase, and in a case in which the heat transfer amount of cold air and water decreases, the first reference time and the second reference time may be reduced.

In addition, the second reference time may be a time when the ice separation heater <NUM> continues to generate heat in a state in which the ice making heater <NUM> does not have a breakdown, all the ice which has cooled in the ice making cell 320a melt and converge to a constant temperature. For example, the second reference time may be around <NUM> minutes.

When it is determined that the ice separation heater <NUM> has a breakdown, the controller <NUM> may perform a step for responding to the breakdown (S12). If it is determined that the ice separation heater <NUM> has a breakdown, all operations of the ice maker <NUM> may be primarily stopped.

Alternatively, the ice separation heater <NUM> may be turned off to prevent power from being continuously supplied to the ice separation heater <NUM> (S121).

However, if ice generated by an already performed operation continues to stay in the ice making cell 320a, there may be a problem that the ice in the ice making cell 320a melts due to a power failure, door opening, or the like in the future. Accordingly, a step for responding to the breakdown of the ice separation heater <NUM> may be performed.

As an example corresponding to the breakdown of the ice separation heater <NUM>, the controller <NUM> may display information indicating that the ice separation heater <NUM> has a breakdown through the output part <NUM>. The user may replace the ice separation heater <NUM> through breakdown information through the output part <NUM>.

As another example corresponding to the breakdown of the ice separation heater <NUM>, the controller <NUM> may turn on the transparent ice heater <NUM> (S122).

When the transparent ice heater <NUM> is turned on, the heat of the transparent ice heater <NUM> is transferred to the contact surface between the first tray <NUM> and the second tray <NUM> to be in a state of being capable of being separated between the lower surface 321d of the first tray <NUM> and the upper surface 381a of the second tray <NUM>. In addition, the heat from the transparent ice heater <NUM> may be transferred to the first tray <NUM> so that ice coupled with the inner surface of the first tray <NUM> may be separated.

After turning on the transparent ice heater <NUM>, the controller <NUM> may determine whether the turn-off reference of the transparent ice heater <NUM> has been satisfied (S123).

For example, in a case in which the temperature sensed by the second temperature sensor <NUM> reaches the turn-off reference temperature (or the second turn-off reference temperature) of the transparent ice heater <NUM>, it is determined that the turn-off reference of the transparent ice heater <NUM> is satisfied. As another example, when the transparent ice heater <NUM> is operated and a predetermined time elapses, it may be determined that the turn-off reference is satisfied.

In addition, it may be determined whether the transparent ice heater <NUM> satisfies the turn-off reference based on whether the transparent ice heater <NUM> has reached the second turn-off reference temperature within a predetermined time. In this case, the second turn-off reference temperature may be equal to or lower than the first turn-off reference temperature.

Since the second temperature sensor <NUM> contacts the first tray <NUM>, the elapsed time is long until the heat of the transparent ice heater <NUM> in contact with the second tray <NUM> is transmitted to the second temperature sensor <NUM>, and thus even if the second turn-off reference temperature is set equal to or lower than the first turn-off reference temperature, heat from the transparent ice heater <NUM> may be sufficiently transferred to the first tray <NUM>.

When the turn-off reference of the transparent ice heater <NUM> is satisfied, the controller <NUM> turns off the transparent ice heater <NUM> (S124).

As another example, when ice making is completed irrespective of a breakdown of the ice separation heater <NUM>, the ice making heater <NUM> and the transparent ice heater <NUM> may be turned on simultaneously or sequentially for ice making. In this case, even if the ice separation heater <NUM> has a breakdown, ice may be easily separated from the tray by the heat of the transparent ice heater <NUM>.

After the transparent ice heater <NUM> is turned off, the controller <NUM> operates the driver <NUM> so that the second tray <NUM> moves in a forward direction for ice separation (S13).

As illustrated in <FIG>, when the second tray <NUM> is moved in the forward direction, the second tray <NUM> is spaced apart from the first tray <NUM>.

Meanwhile, the moving force of the second tray <NUM> is transmitted to the first pusher <NUM> by the pusher link <NUM>. Then, the first pusher <NUM> descends along the guide slot <NUM>, so that the extension part <NUM> passes through the communication hole 321e and presses the ice in the ice making cell 320a.

In this embodiment, in the ice separation process, the ice may be separated from the first tray <NUM> before the extension part <NUM> presses the ice. That is, ice may be separated from the surface of the first tray <NUM> by the heat of the heater which is turned on. In this case, the ice may move together with the second tray <NUM> in a state of being supported by the second tray <NUM>.

As another example, even if the heat of the heater is applied to the first tray <NUM>, there may be a case in which ice is not separated from the surface of the first tray <NUM>.

Accordingly, when the second tray <NUM> moves in the forward direction, there is a possibility that ice may be separated from the second tray <NUM> in a state in which the ice is in close contact with the first tray <NUM>.

In this state, in the process of moving the second tray <NUM>, the extension part <NUM> passing through the communication hole 320e presses the ice in close contact with the first tray <NUM>, so that the ice may be separated from the first tray <NUM>. Ice separated from the first tray <NUM> may be supported by the second tray <NUM>.

In a case in which ice moves together with the second tray <NUM> in a state of being supported by the second tray <NUM>, the ice can be separated from the second tray <NUM> by the own weight thereof even if no external force is applied to the second tray <NUM>.

If, in the process of moving the second tray <NUM>, even if ice does not fall from the second tray <NUM> by own weight thereof, when the second tray <NUM> is pressed by the second pusher <NUM> as in <FIG>, ice may be separated from the second tray <NUM> and fall downward.

Specifically, as illustrated in <FIG>, in a process in which the second tray <NUM> moves, the second tray <NUM> contacts the extension part <NUM> of the second pusher <NUM>.

When the second tray <NUM> continuously moves in the forward direction, the extension part <NUM> presses the second tray <NUM> to deform the second tray <NUM>, and the pressing force of the extension part <NUM> is transmitted to the ice so that the ice may be separated from the surface of the second tray <NUM>. Ice separated from the surface of the second tray <NUM> may fall down and be stored in the ice bin <NUM>.

In this embodiment, as illustrated in <FIG>, a position in which the second tray <NUM> is deformed by being pressed by the second pusher <NUM> may be referred to as an ice separation position.

Meanwhile, in a process in which the second tray <NUM> moves from the ice making position to the ice separation position, it may be detected whether ice is full in the ice bin <NUM>.

For example, when the ice full detection lever <NUM> is rotated together with the second tray <NUM> and the rotation of the ice full detection lever <NUM> interferes with the ice in a process in which the ice full detection lever <NUM> is rotated, it may be determined that the ice bin <NUM> is in an ice full state. On the other hand, if the rotation of the full ice detection lever <NUM> is not interfered with by ice in a process in which the ice full detection lever <NUM> is rotated, it may be determined that the ice bin <NUM> is not in an ice full state.

After the ice is separated from the second tray <NUM>, the controller <NUM> controls the driver <NUM> to move the second tray <NUM> in the reverse direction (S14). Then, the second tray <NUM> moves from the ice separation position toward the water supply position.

When the second tray <NUM> moves to the water supply position of <FIG>, the controller <NUM> stops the driver <NUM> (S1).

When the second tray <NUM> is spaced apart from the extension part <NUM> in a process in which the second tray <NUM> is moved in the reverse direction, the deformed second tray <NUM> may be restored to the original shape thereof.

In the process of moving the second tray <NUM> in the reverse direction, the moving force of the second tray <NUM> is transferred to the first pusher <NUM> by the pusher link <NUM>, and the first pusher <NUM> rises, and the extension part <NUM> is removed from the ice making cell 320a.

Meanwhile, in this embodiment, the cooling power of the cold air supply part <NUM> may be determined in correspondence with the target temperature of the freezing compartment <NUM>. The cold air generated by the cold air supply part <NUM> may be supplied to the freezing compartment <NUM>.

Water in the ice making cell 320a may be phase-changed into ice by heat transfer of the cold air supplied to the freezing compartment <NUM> and the water in the ice making cell 320a.

In this embodiment, the heating amount of the transparent ice heater <NUM> for each unit height of water may be determined in consideration of a predetermined cooling power of the cold air supply part <NUM>.

The heating amount (or output) of the transparent ice heater <NUM> determined in consideration of the predetermined cooling power of the cold air supply part <NUM> is referred to as a reference heating amount (or reference output). The size of the reference heating amount per unit height of the water is different.

However, when the heat transfer amount between the cold air of the freezing compartment <NUM> and the water in the ice making cell 320a is varied, if the heating amount of the transparent ice heater <NUM> is not adjusted to reflect this, there is a problem that the transparency of ice for each unit height is changed.

In this embodiment, a case in which the heat transfer amount of cold air and water increases may be a case in which, for example, the cooling power of the cold air supply part <NUM> increases, or a case in which air having a temperature lower than the temperature of the cold air in the freezing compartment <NUM> is supplied to the freezing compartment <NUM>.

On the other hand, a case in which the heat transfer amount of cold air and water is reduced may be a case in which, for example, the cooling power of the cold air supply part <NUM> is reduced, a case in which the door is opened and air having the temperature which is higher than the temperature of the cold air in the freezing compartment <NUM> is supplied to the freezing compartment <NUM>, a case in which food having a temperature higher than the temperature of cold air in the freezing compartment <NUM> is put into the freezing compartment <NUM>, or a case in which a defrost heater (not illustrated) for defrosting the evaporator is turned on.

For example, in a case in which the target temperature of the freezing compartment <NUM> is lowered, the operating mode of the freezing compartment <NUM> is changed from the normal mode to the rapid cooling mode, the output of at least one of the compressor and the fan increases, or the opening degree of the refrigerant valve increases, the cooling power of the cold air supply part <NUM> may increases.

On the other hand, the target temperature of the freezing compartment <NUM> increases, the operating mode of the freezing compartment <NUM> is changed from the rapid cooling mode to the normal mode, the output of at least one of the compressor and the fan is reduced, or the opening degree of the refrigerant valve is reduced, the cooling power of the cold air supply part <NUM> may be reduced.

In a case in which the heat transfer amount of the cold air and water increases, the temperature of the cold air around the ice maker <NUM> decreases, thereby increasing the rate of ice generation. On the other hand, when the heat transfer amount of the cold air and water is reduced, the temperature of the cold air around the ice maker <NUM> increases, so that the rate of ice generation is slowed, and the ice making time is lengthened.

Therefore, in this embodiment, in a case in which the heat transfer amount of cold air and water increases so that the ice making speed can be maintained within a predetermined range lower than the ice making speed when ice making is performed while the transparent ice heater <NUM> is turned off, the heating amount of the transparent ice heater <NUM> may be controlled to increase.

On the other hand, in a case in which the heat transfer amount of the cold air and water is reduced, the heating amount of the transparent ice heater <NUM> may be controlled to be reduced.

In this embodiment, when the ice making speed is maintained within the predetermined range, the ice making speed becomes slower than the speed at which the bubbles move in the ice-generating portion from the ice making cell 320a so that no bubbles exist in the ice-generating portion.

<FIG> is a flowchart illustrating a process of generating ice in an ice maker according to another embodiment of the present invention, and <FIG> is a flowchart illustrating a process in which ice is separated in an ice maker according to another embodiment of the present invention.

Since the description of <FIG> and <FIG> differs between the previous embodiment and the ice separation method, only characteristic parts of this embodiment will be described below.

Referring to <FIG> and <FIG>, in order to generate ice in the ice maker <NUM>, the controller <NUM> moves the second tray <NUM> to a water supply position (S1). Water supply is started in a state in which the second tray <NUM> is moved to the water supply position (S2).

After the water supply is completed, the controller <NUM> controls the driver <NUM> to move the second tray <NUM> to the ice making position (S3). The ice making starts in a state in which the second tray <NUM> is moved to the ice making position (S4).

The controller <NUM> may determine whether the ice making is completed based on the temperature sensed by the second temperature sensor <NUM> (S6). When it is determined that ice making is completed, the controller <NUM> may turn off the transparent ice heater <NUM> (S7).

When the ice making is completed, the controller <NUM> operates the ice separation heater <NUM> (S8). When the ice separation heater <NUM> is turned on, heat from the heater is transferred to the first tray <NUM> so that ice may be separated from the surface (inner surface) of the first tray <NUM>.

However, when the heat transfer amount between the cold air in the freezing compartment <NUM> and the water in the ice making cell 320a is varied, if the heating amount of the ice separation heater <NUM> is not adjusted to reflect this, since the ice may excessively melt or ice does not melt enough, there may be a problem that the ice separation is not smooth.

In this embodiment, a case in which the heat transfer amount of cold air and water is increased may be, for example, a case in which the cooling power of the cold air supply part <NUM> increases, or a case in which air having a temperature lower than the temperature of the cold air in the freezing compartment <NUM> is supplied to the freezing compartment <NUM>.

On the other hand, a case in which the heat transfer amount of cold air and water is reduced may be , for example, a case in which the cooling power of the cold air supply part <NUM> is reduced, a case in which the door is opened and the air of the temperature which is higher than the temperature of the cold air in the freezing compartment <NUM> is supplied to the freezing compartment <NUM>, a case in which food with a temperature higher than the temperature of cold air in the freezing compartment <NUM> is put into the freezing compartment <NUM>, or a case in which a defrost heater (not illustrated) for defrosting the evaporator is turned on.

For example, in a case in which the target temperature of the freezing compartment <NUM> is lowered, the operating mode of the freezing compartment <NUM> is changed from the normal mode to the rapid cooling mode, the output of at least one of the compressor and the fan increases, or the opening degree of the refrigerant valve increases, the cooling power of the cold air supply part <NUM> may increases. On the other hand, in a case in which the target temperature of the freezing compartment <NUM> increases, the operating mode of the freezing compartment <NUM> is changed from the rapid cooling mode to the normal mode, the output of at least one of the compressor and the fan is reduced, or the opening degree of the refrigerant valve is reduced, the cooling power of the cold air supply part <NUM> may be reduced.

In a case in which the heat transfer amount of the cold air and water increases, the temperature of the cold air around the ice maker <NUM> decreases, thereby increasing the rate of ice generation. On the other hand, when the heat transfer amount of the cold air and water decreases, the cold air temperature around the ice maker <NUM> increases, so that the rate of ice generation is slowed and the ice making time is lengthened.

Accordingly, in this embodiment, when the heat transfer amount of cold air and water increases, the heating amount of the ice separation heater <NUM> may be controlled to increase. On the other hand, in a case in which the heat transfer amount of the cold air and water is reduced, the heating amount of the ice separation heater <NUM> may be controlled to decrease.

As another example, it goes without saying that the ice separation heater <NUM> may transfer heat to the first tray <NUM> with a constant output.

In detail, if the cooling power of the cold air supply part <NUM> is higher when the cooling power of the cold air supply part <NUM> is the second cooling power than when the cooling power thereof is the first cooling power during the ice making process, the controller can control the heating amount of the ice separation heater <NUM> to be larger when the cooling power of the cold air supply part <NUM> is the second cooling power than when the cooling power thereof is the first cooling power.

The high cooling power of the cold air supply part <NUM> means that the heat transfer amount of cold air and water increases, so as to prevent the case in which the ice is not separated due to insufficient heating amount of the ice separation heater <NUM> if the cooling power of the cold air supply part <NUM> is high, the heating amount of the ice separation heater <NUM> may be controlled to be larger.

In addition, if the target temperature of the storage chamber set by the user is higher in the second temperature than in the first temperature, the controller <NUM> can control so that the heating amount of the ice separation heater <NUM>, when the target temperature is the second temperature is smaller.

In addition, according to a similar principle, if the door opening time in the ice making process or the turn-on time of the defrost heater operating for defrosting is longer in the second time than in the first time, the controller <NUM> can control so that the heating amount of the ice separation heater <NUM> is smaller when the door opening time in the ice making process or the turn-on time of the defrost heater operating for defrosting is the second time.

After the ice separation heater <NUM> is turned on when the moving condition of the second tray <NUM> is satisfied, the controller <NUM> can rotate the second tray <NUM> in the forward direction so that the second tray <NUM> is moved to a standby position (or an additional heating position) in the forward direction (S31).

The moving condition of the second tray <NUM> may be determined based on at least one of the turn-on times of the ice separation heater <NUM> and a temperature sensed by the second temperature sensor <NUM>.

When the second tray <NUM> is moved in the forward direction, the second tray <NUM> is spaced apart from the first tray <NUM>. As an example, the standby position may be a state in which the second tray <NUM> is moved further in the forward direction than the water supply position, and the second tray <NUM> is moved further in the reverse direction than the ice separation position. That is, the additional heating position may be between the water supply position and the ice separation position.

The angle between the lower surface 321d of the first tray <NUM> and the upper surface 381a of the second tray <NUM> at the additional heating position may be referred to as a first angle, and the first angle may be <NUM> degrees to <NUM> degrees.

In this embodiment, before the second tray <NUM> rotates in the forward direction, ice may be separated from the surface of the first tray <NUM> by the heat of the turned-on ice separation heater <NUM>. In this case, the ice may move together with the second tray <NUM> in a state of being supported by the second tray <NUM>.

As another example, even if the heat of the ice separation heater <NUM> is applied to the first tray <NUM>, there may be a case in which ice is not separated from the surface of the first tray <NUM>.

That is, when the second tray <NUM> is moved to the additional heating position, ice may be in a state of being settled on the second tray <NUM> in a cell separated from the first tray <NUM> among the plurality of ice making cells 320a and in the remaining cells, ice may be in a state of being attached to the first tray <NUM>.

After the second tray <NUM> is rotated in the forward direction to the standby position, it is determined whether the turn-off reference of the ice separation heater <NUM> is satisfied (S32).

The turn-off reference of the ice separation heater <NUM> may be determined based on at least one of the turn-on times of the ice separation heater <NUM> and a temperature sensed by the second temperature sensor <NUM>.

When the off reference of the ice separation heater <NUM> is satisfied, the controller <NUM> turns off the ice separation heater <NUM> (S33).

After the ice separation heater <NUM> is turned on, until the ice separation heater <NUM> is turned off, the ice separation heater <NUM> may maintain a turn-on state when the second tray <NUM> moves to the standby position.

Another example after the ice separation heater <NUM> is turned on, until the ice separation heater <NUM> is turned off and then the second tray <NUM> moves to the ice separation position will be described with reference to <FIG>.

After the ice making heater <NUM> first transfers heat from the ice making position to the ice making cell 320a and is turned off, the second tray <NUM> is moved to the standby position, and the ice separation heater <NUM> may be turned on at the standby position again. That is, when the moving condition of the second tray <NUM> is satisfied, the controller <NUM> may turn off the ice separation heater <NUM>, and when the second tray <NUM> is moved to the standby position, the controller <NUM> may turn on the ice separation heater <NUM> again.

The moving condition of the second tray <NUM> for turning off the ice separation heater <NUM> may be a case in which the temperature sensed by the second temperature sensor <NUM> reaches the turn-off reference temperature (or first turn-off reference temperature) or more of the ice separation heater <NUM> or (S41), or a case of being operated during the turn-off reference time (S42). The turn-off reference time may be referred to as a first reference time.

In addition, in a case in which the temperature sensed by the second temperature sensor <NUM> reaches the first turn-off reference temperature during the turn-off reference time, the ice separation heater <NUM> may be turned off.

As an example, when the temperature sensed by the second temperature sensor <NUM> reaches the first turn-off reference temperature during a sufficient turn-off reference time to allow all ice to be separated in the plurality of ice making cells 320a, it may be determined that the moving condition of the tray <NUM> is satisfied.

However, in this case, some of the plurality of ice making cells 320a may excessively melt, and thus melting water may drop into the ice bin <NUM>.

Accordingly, as another example, a turn-off reference time or a first turn-off reference temperature at which only some of the plurality of ice making cells 320a are separated may be set. That is, the first turn-off reference temperature may be a temperature at which it is determined that ice in some ice making cells 320a among the plurality of ice making cells 320a can be separated, and the turn-off reference time may be a time at which it is determined that ice in some ice making cells 320a among the plurality of ice making cells 320a can be separated.

Although not limited, the first turn-off reference temperature may be set as the above-zero temperature. Alternatively, the first turn-off reference temperature may be set to a temperature higher than the first reference temperature.

When the movement condition of the second tray <NUM> is satisfied, the controller <NUM> turns off the ice separation heater <NUM> (S43). After the ice separation heater <NUM> is turned off, the second tray <NUM> may be rotated by a first angle in the forward direction and moved to the standby position (S44).

The controller <NUM> may turn on the ice separation heater <NUM> again for additional heating for separating ice attached to the first tray <NUM> (S45).

Even after the second tray <NUM> is moved to the additional heating position, since some of the ice making cells 320a are attached to the first tray <NUM> and remain in a state of not melting, the controller <NUM> may operate the ice separation heater <NUM>.

By additionally operating the ice separation heater <NUM>, the load applied to the first pusher <NUM> may be reduced, thereby preventing the first pusher <NUM> from being damaged.

After the ice separation heater <NUM> is operated, when the second reference time elapses, the ice separation heater <NUM> may be turned off (S46, S47).

The second reference time may be a time sufficient to melt ice attached to the first tray <NUM> and not settled in the second tray <NUM> among the plurality of ice making cells 320a.

In addition, since ice attached to the first tray <NUM> may be easily separated from the first tray <NUM> due to the influence of gravity, the second reference time may be shorter than the first reference time. For example, the second reference time may be about <NUM> seconds.

After the ice separation heater <NUM> is turned off, the ice separation heater <NUM> may wait for a predetermined time so that the melting water by the ice separation heater <NUM> is cooled (S48).

When the water melting due to the heat of the ice separation heater <NUM> drops into the ice bin <NUM>, a mat of ice cubes may be generated inside the ice bin <NUM>, or the shape of the ice may be deformed due to the melting water. In order to prevent such a problem, after waiting for a predetermined time to cool the melting water, ice may be separated into the ice bin <NUM>.

The controller <NUM> may make the second tray <NUM> wait for a predetermined time (or waiting time) (S48). The waiting time may be a time sufficient for the melting water to cool and is preferably longer than the second reference time.

As an example, in a state in which the second tray <NUM> is in the additional heating position, the second tray <NUM> may wait for a predetermined time.

As another example, after the ice separation heater <NUM> additionally transfers heat to the second tray <NUM>, the controller <NUM> may also make the second tray <NUM> wait for a predetermined time at the specific position in which the second tray <NUM> is further moved in a forward direction. The specific position may be between the standby position and the ice separation position.

Through this, the ice inside the ice making cell 320a may not be separated into the ice bin <NUM> and cold air may be easily introduced into the ice making cell 320a.

When the waiting time has elapsed, the controller <NUM> may rotate the second tray <NUM> in a forward direction to move the second tray <NUM> to the ice separation position (S13).

After the ice is separated from the second tray <NUM>, the controller <NUM> controls the driver <NUM> to move the second tray <NUM> in the reverse direction (S14). Then, the second tray <NUM> moves from the ice separation position toward the water supply position. When the second tray <NUM> moves to the water supply position, the controller <NUM> stops the driver <NUM>.

Claim 1:
A refrigerator comprising:
a storage chamber configured to store food;
a cold air supply part (<NUM>) configured to supply cold air to the storage chamber;
a tray configured to form an ice making cell (320a) being a space in which water is phase-changed into ice by the cold air;
a temperature sensor (<NUM>) configured to sense the temperature of water or ice in the ice making cell (320a);
a heater (<NUM>) configured to provide heat to the tray; and
a controller (<NUM>) configured to control the heater (<NUM>),
wherein the controller (<NUM>) is configured to control the heater (<NUM>) to be turned on so that ice can be easily separated from the tray when the ice making is completed, and
wherein the controller (<NUM>) is configured to control the heater (<NUM>) to be turned off when a temperature sensed by the temperature sensor (<NUM>) reaches a first turn-off reference temperature greater than zero after a first reference time elapses in a state in which the heater (<NUM>) is turned on.