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 <CIT> (hereinafter, referred to as a "prior art document <NUM>") that is a prior art document.

The ice maker disclosed in the prior art document <NUM> 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 prior art document <NUM>, although the spherical ice is made by the hemispherical upper cell and the hemispherical lower cell, since the ice is made at the same time in the upper and lower cells, bubbles containing water are not completely discharged but are dispersed in the water to make opaque ice.

The ice maker disclosed in the prior art document <NUM> includes an ice making plate and a heater for heating a lower portion of water supplied to the ice making plate.

In the case of the ice maker disclosed in the prior art document <NUM>, water on one surface and a bottom surface of an ice making block is heated by the heater in an ice making process. Thus, when solidification proceeds on the surface of the water, and also, convection occurs in the water to make transparent ice.

When growth of the transparent ice proceeds to reduce a volume of the water within the ice making block, the solidification rate is gradually increased, and thus, sufficient convection suitable for the solidification rate may not occur.

Thus, in the case of the prior art document <NUM>, when about <NUM>/<NUM> of water is solidified, a heating amount of heater increases to suppress an increase in the solidification rate.

However, the prior art document <NUM> discloses a feature in which when the volume of water is simply reduced, only the heating amount of heater increases and does not disclose a structure and a heater control logic for making ice having high transparency without reducing the ice making rate.

<CIT> presents an ice making device that includes: an ice making tray for storing water supplied thereto, and making ice from the stored water by receiving cold air supplied from a refrigeration cycle; a temperature sensor for measuring the temperature of the ice making tray; a heater for heating the ice making tray; and a control part for controlling power distribution to the heater based on the measured temperature by the temperature sensor. The control part starts power supply to the heater after water supply, and then controls to reduce the amount of power supplied to the heater through time if it is determined that when an elapsed time after the water supply indicates a regular predetermined time for ice making, the measured time by the temperature sensor does not indicate the predetermined time for ice making.

According to the invention a refrigerator is provided capable of making ice having uniform transparency as a whole regardless of shape.

According to the embodiments, since the heater is turned on in at least a portion of the sections while the cooler supplies cold, the ice making rate may decrease by the heat of the heater so that the bubbles dissolved in the water inside the ice making cell move toward the liquid water from the portion at which the ice is made, thereby making the transparent ice.

In particular, according to the invention, the heating amount of the heater may be controlled to vary according to the mass per unit height of water in the ice making cell to make the ice having the uniform transparency as a whole regardless of the shape of the ice making cell.

In addition, according to this embodiment, ice may be completely made ice in an ice making cell through an additional heating process of a transparent ice heater even when a temperature of a storage chamber increases or cold air supplied to the storage chamber decreases.

The refrigerator according to an embodiment may include a tray assembly defining a portion of an ice making cell that is a space in which water is phase-changed into ice, a cooler supplying cold air to the ice making cell, a water supply part supplying water to the ice making cell, and a controller.

The refrigerator may further include a temperature sensor detecting a temperature of water or ice of the ice making cell. The refrigerator further includes a heater disposed adjacent to the tray assembly. The refrigerator may further include a driver to move the tray assembly.

The heater may supply heat to the ice making cell and/or the tray assembly.

The refrigerator further includes a storage chamber in which food is stored in addition to the ice making cell. The refrigerator further includes a cooler supplying cold to the storage chamber. The refrigerator may further include a temperature sensor sensing a temperature in the storage chamber. The controller may control at least one of the water supply part or the cooler. The controller controls the heater. The controller may control the driver.

The cooler may be defined as a part configured to cool the storage chamber that includes at least one of a cold air supply part including an evaporator and a thermoelectric element.

Hereinafter, embodiments of the refrigerator will be described in detail with reference to the drawings. An example in which the cooler includes the cold air supply part will be described.

<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 chambers 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>, and <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 showing a second temperature sensor installed in an ice maker according to an embodiment.

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

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 on the upper side of the inner surface of the bracket <NUM>. The water supply part <NUM> may be provided with openings at upper and lower sides 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>. Since the upper opening of the water supply part <NUM> is larger than the lower opening thereof, a discharge range of water guided downward through the water supply part <NUM> may be limited. A water supply pipe to 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 320a in which water is phase-changed into ice by the cold air.

The ice maker <NUM> may include a first tray <NUM> defining at least a portion of a wall for providing the ice making cell 320a, and a second tray <NUM> defining 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>. 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. In this case, the first cell 320b may be provided in a spherical shape or a shape similar to a spherical shape. Also, the second cell 320c 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.

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

For example, the first tray case <NUM> may be coupled to the upper side of the first tray <NUM>. The first tray case <NUM> may be manufactured as a separate part from the bracket <NUM> and then may be coupled to the bracket <NUM> or integrally formed with the bracket <NUM>.

The ice maker <NUM> may further include a first heater case <NUM>. An ice separation heater <NUM> 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 any cases, 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> disposed below the first tray <NUM>. The first tray cover <NUM> may be provided with an opening corresponding to a shape of the ice making cell 320a of the first tray <NUM> and may be coupled to a 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>, which will 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 part <NUM>. For example, the first pusher <NUM> may include the extension part <NUM> provided with the same number as the number of ice making cells 320a, but is not limited thereto. The extension part <NUM> may push out the ice disposed in the ice making cell 320a during the ice separation process. For example, the extension part <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 include a second tray case <NUM> coupled to the second tray <NUM>.

The second tray case <NUM> may be disposed at a lower side of the second tray to support the second tray <NUM>. For example, at least a portion of the wall defining the second cell 320a 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 surround the circumferential wall <NUM>.

The ice maker <NUM> may further include a second heater case <NUM>. A transparent ice heater <NUM> 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 an 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.

On the other hand, at least one of the first tray <NUM> and the second tray <NUM> may be made of a resin including plastic so that the ice attached to the trays <NUM> and <NUM> is separated in the ice making process.

On the other hand, at least one of the first tray <NUM> or the second tray <NUM> may be made of a flexible or soft material so that the tray deformed by the pushers <NUM> and <NUM> is easily restored to its original shape in 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, for example, a wire type heater. For example, the transparent ice heater <NUM> may be installed to contact the second tray <NUM> or may be disposed at a position spaced a predetermined distance from the second tray <NUM>. For another example, the second heater case <NUM> may not be separately provided, but the transparent heater <NUM> may be installed on the second tray case <NUM>. In any 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>. 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 and an ice making 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 on the bracket <NUM>. The second pusher <NUM> may include at least one extension part <NUM>. For example, the second pusher <NUM> may include the extension part <NUM> provided with the same number as the number of ice making cells 320a, but is not limited thereto. The extension part <NUM> may push out the ice disposed in the ice making cell 320a. For example, the extension part <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 be provided with 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 shaft <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 silicone 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.

For another example, the first tray <NUM> may be made of a metal material. In this case, since the coupling force or the separating 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 second tray <NUM> may be made of, for example, a silicone 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>.

On the other hand, referring to <FIG>, the ice maker <NUM> may further include a second temperature sensor (or a tray temperature sensor) <NUM> that senses the 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, when the second temperature sensor <NUM> is disposed to pass through the first tray <NUM>, the temperature of water or ice of the ice making cell 320a may be directly sensed.

On the other hand, a portion of the ice separation heater <NUM> may be disposed higher than the second temperature sensor <NUM> and may be spaced apart from the second temperature sensor <NUM>. An electric wire <NUM> coupled 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 such that the position of the second tray <NUM> is different in the water supply position and the ice-making position. For example, the second tray <NUM> may include a second cell wall <NUM> defining the second cell 320c of the ice making cell 320a, and a circumferential wall <NUM> extending along the 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 disposed lower than the upper end of the circumferential wall <NUM>.

The first tray <NUM> may include a first cell wall 321a defining the first cell 320b of the ice making cell 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 circumferential 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 this specification, the lower surface 321b of the first cell wall 321a may be referred to as 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, at least a portion of the lower surface 321d of the first cell wall 321a and the upper surface 381a of the second cell wall <NUM> may be spaced apart at the water supply position as shown in <FIG>. In <FIG>, for example, it is shown that the lower surface 321d of the first cell wall 321a and the entire upper surface 381a of the second cell wall <NUM> 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, the lower surface 321d of the first cell wall 321a at the water supply position may be maintained substantially horizontally, 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 shown in <FIG>, the circumferential wall <NUM> may surround the first cell wall 321a. In addition, the upper end of the circumferential wall <NUM> may be disposed higher than the lower surface 321d of the first cell wall 321a. On the other hand, 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 at the ice making position (see <FIG>). The angle formed by 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 formed by the upper surface 382a of the second tray <NUM> and the lower surface 321d of the first tray <NUM> at the water supply position. The upper surface 381a of the second cell wall <NUM> may contact the entire lower surface 321d of the first cell wall 321a at the ice making position. At the ice making position, the upper surface 381a of the second cell wall <NUM> and the lower surface 321d of the first cell wall 321a may be disposed to be substantially horizontal.

In this embodiment, the water supply position of the second tray <NUM> and the ice making position are different from each other so that, when the ice maker <NUM> includes a plurality of ice making cells 320a, a water passage for communication between the ice making cells 320a is not formed in the first tray <NUM> and/or the second tray <NUM>, and water is uniformly distributed to the plurality of ice making cells 320a.

If the ice maker <NUM> includes the plurality of ice making cells 320a, when the 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 also exists in the water passage, and when ice is made in this state, the ice made in the ice making cell 320a is connected by the ice made in the water passage.

In this case, there is a possibility that the ice will stick together even after the ice separation is completed. Even if pieces of ice are separated from each other, some pieces of ice will contain ice made in the water passage, and thus there is a problem that the shape of the ice is different from that of the ice making cell.

However, as in this embodiment, when the second tray <NUM> is spaced apart from the first tray <NUM> at the water supply position, water falling into 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. When 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, the water supplied through the one communication hole 321e falls into the second tray <NUM> after passing through the first tray <NUM>.

During the water supply process, water may fall into any one second cell 320c among the plurality of second cells 320c of the second tray <NUM>. The 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 that overflows from one of the second cells 320c moves to another adjacent second cell 320c along the upper surface 381a of the second tray <NUM>. Accordingly, the plurality of second cells 320c of the second tray <NUM> may be filled with water.

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

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

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

On the other hand, when the water passage is defined in the first tray <NUM> and/or the second tray <NUM>, ice made in the ice making cell 320a is also made in the water passage portion.

In this case, when the controller of the refrigerator controls the heating amount of the transparent ice heater <NUM> to vary according to the mass per unit height of water in the ice making cell 320a in order to make transparent ice, the heating amount of the transparent ice heater <NUM> is controlled to rapidly vary several times or more in the portion where the water passage is defined.

This is because the mass per unit height of water is rapidly increased several times or more in the portion where the water passage is defined. In this case, since the reliability problem of the parts may occur and expensive parts with large widths of maximum and minimum output may be used, it can also be disadvantageous in terms of power consumption and cost of parts. As a result, the present disclosure may require a technology related to the above-described ice making position so as to make 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 further include a cold air supply part <NUM> supplying 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.

In addition, the cold air supply part <NUM> may further include the evaporator exchanging heat between the refrigerant and the air. The cold air heat-exchanged with the evaporator may be supplied to the ice maker <NUM>.

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

The controller <NUM> may control a portion or all of the ice separation heater <NUM>, the transparent ice heater <NUM>, the driver <NUM>, the cold air supply part <NUM>, and the water supply valve <NUM>.

In this embodiment, when the ice maker <NUM> includes both the ice separation heater <NUM> and the transparent ice heater <NUM>, an output of the ice separation heater <NUM> and an output of the transparent ice heater <NUM> may be different from each other.

When the outputs of the ice separation heater <NUM> and the transparent ice heater <NUM> are different from each other, an output terminal of the ice separation heater <NUM> and an output terminal of the transparent ice heater <NUM> may be provided in different shapes, incorrect connection of the two output terminals may be prevented.

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

In this embodiment, when the ice separation heater <NUM> is not provided, the transparent ice heater <NUM> may be disposed at a position adjacent to the second tray <NUM> described above or be disposed at a position adjacent to the first tray <NUM>.

The refrigerator may further include a first temperature sensor <NUM> (or an internal temperature sensor) that senses a 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.

<FIG> is a view for explaining a height reference depending on a relative position of the transparent heater with respect to the ice making cell, and <FIG> is a view for explaining an output of the transparent heater per unit height of water in the ice making cell.

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

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

In this 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 forward movement (or forward rotation). On the other hand, the direction from the ice separation position of <FIG> to the water supply position of <FIG> may be referred to as reverse movement (or reverse rotation).

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

The water supply starts when the second tray <NUM> moves to the water supply position (S2).

For the water supply, the controller <NUM> turns on the water supply valve <NUM>, and when it is determined that a predetermined amount of water is supplied, the controller <NUM> may turn off the water supply valve <NUM>. For example, in the process of supplying water, when a pulse is outputted from a flow sensor (not shown), and the outputted pulse reaches a reference pulse, it may be determined that a predetermined amount of water is supplied.

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

When the second tray <NUM> moves in the reverse direction, the upper surface 381a of the second tray <NUM> comes close to the lower surface 321e of the first tray <NUM>. Then, water between the upper surface 381a of the second tray <NUM> and the lower surface 321e of the first tray <NUM> is divided into each of the plurality of second cells 320c and then is distributed. 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 to the ice making position of the second tray <NUM> is detected by a sensor, and when it is detected that the second tray <NUM> moves to the ice making position, the controller <NUM> stops the driver <NUM>.

In the state in which the second tray <NUM> moves to the ice making position, ice making is started (S4). For example, the ice making may be started when the second tray <NUM> reaches the ice making position. Alternatively, when the second tray <NUM> reaches the ice making position, and the water supply time elapses, the ice making may be started.

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

After the ice making is started, the controller <NUM> may control the transparent ice heater <NUM> to be turned on in at least partial sections of the cold air supply part <NUM> supplying the cold air to the ice making cell 320a. When the transparent ice heater <NUM> is turned on, since the heat of the transparent ice heater <NUM> is transferred to the ice making cell 320a, the ice making rate of the ice making cell 320a may be delayed.

According to this embodiment, the ice making rate may be delayed so that the bubbles dissolved in the water inside the ice making cell 320a move from the portion at which ice is made toward the liquid water by the heat of the transparent ice heater <NUM> to make the transparent ice in the ice maker <NUM>.

In the ice making process, the controller <NUM> may determine whether the turn-on condition of the transparent ice heater <NUM> is satisfied (S5).

In this embodiment, the transparent ice heater <NUM> is not turned on immediately after the ice making is started, and the transparent ice heater <NUM> may be turned on only when the turn-on condition of the transparent ice heater <NUM> is satisfied (S6).

Generally, the water supplied to the ice making cell 320a may be water having normal temperature or water having a temperature lower than the normal temperature. The temperature of the water supplied is higher than a freezing point of water. Thus, after the water supply, the temperature of the water is lowered by the cold air, and when the temperature of the water reaches the freezing point of the water, the water is changed into ice.

In this embodiment, the transparent ice heater <NUM> may not be turned on until the water is phase-changed 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 temperature of the water reaches the freezing point by the heat of the transparent ice heater <NUM> is slow. As a result, the starting of the ice making may be delayed.

The transparency of the ice may vary depending on the presence of the air bubbles in the portion at which ice is made after the ice making is started. If heat is supplied to the ice making cell 320a before the ice is made, the transparent ice heater <NUM> may operate regardless of the transparency of the ice.

Thus, according to this embodiment, after the turn-on condition of the transparent ice heater <NUM> is satisfied, when the transparent ice heater <NUM> is turned on, power consumption due to the unnecessary operation of the transparent ice heater <NUM> may be prevented.

Alternatively, even if the transparent ice heater <NUM> is turned on immediately after the start of ice making, since the transparency is not affected, it is also possible to turn on the transparent ice heater <NUM> after the start of the 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 the 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 to a time point at which the cold air supply part <NUM> starts to supply cooling power for the ice making, a time point at which the second tray <NUM> reaches the ice making position, a time point at which the water supply is completed, and the like.

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

For example, the turn-on reference temperature may be a temperature for determining that water starts to freeze at the uppermost side (communication hole side) of the ice making cell 320a. When a portion of the water is frozen in the ice making cell 320a, the temperature of the ice in the ice making cell 320a is below zero. The temperature of the first tray <NUM> may be higher than the temperature of the ice in the ice making cell 320a.

Alternatively, although water is present in the ice making cell 320a, after the ice starts to be made in the ice making cell 320a, the temperature sensed by the second temperature sensor <NUM> may be below zero.

Thus, to determine that making of ice is started in the ice making cell 320a on the basis of the temperature detected by the second temperature sensor <NUM>, the turn-on reference temperature may be set to the below-zero temperature.

That is, when the temperature sensed by the second temperature sensor <NUM> reaches the turn-on reference temperature, since the turn-on reference temperature is below zero, the ice temperature of the ice making cell 320a is below zero, i.e., lower than the below reference temperature. Therefore, it may be indirectly determined that ice is made in the ice making cell 320a.

As described above, when the transparent ice heater <NUM> is not used, the heat of the transparent ice heater <NUM> is transferred into the ice making cell 320a.

In this embodiment, when the second tray <NUM> is disposed below the first tray <NUM>, the transparent ice heater <NUM> is disposed to supply the heat to the second tray <NUM>, the ice may be made from an upper side of the ice making cell 320a.

In this embodiment, since ice is made from the upper side in the ice making cell 320a, the bubbles move downward from the portion at which the ice is made in the ice making cell 320a toward the liquid water.

Since density of water is greater than that of ice, water or bubbles may convex in the ice making cell 320a, and the bubbles may move to 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, when 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, when the ice making cell 320a has a shape such as a sphere, an inverted triangle, a crescent moon, etc., the mass (or volume) per unit height of water is different.

When 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 in the ice making cell 320a is different, an ice making rate per unit height may be different.

For example, if the mass per unit height of water is small, the ice making rate is high, whereas if the mass per unit height of water is high, the ice making rate is slow.

As a result, the ice making rate per unit height of water is not constant, and thus, the transparency of the ice may vary according to the unit height. In particular, when ice is made at a high rate, the bubbles may not move from the ice to the water, and the ice may contain the bubbles to lower the transparency.

That is, the more the variation in ice making rate per unit height of water decreases, the more the variation in transparency per unit height of made ice may decrease.

Therefore, in this embodiment, the control part <NUM> may control the heating amount so that the heating amount of the transparent ice heater <NUM> is variable according to the mass per unit height of the water of the ice making cell 320a. The control part <NUM> may also control the cooling power so that the cooling power of the cold air supply part <NUM> is variable according to the mass per unit height of the water of the ice making cell 320a.

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

Also, in this specification, the variation in the heating amount of the transparent ice heater <NUM> may represent varying the output of the transparent ice heater <NUM> or varying the duty of the transparent ice heater <NUM>.

In this case, the duty of the transparent ice heater <NUM> represents a ratio of the turn-on time and a sum of the turn-on time and the turn-off time of the transparent ice heater <NUM> in one cycle, or a ratio of the turn-ff time and a sum of the turn-on time and the turn-off time of the transparent ice heater <NUM> in one cycle.

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

For example, as shown in <FIG>, the transparent ice heater <NUM> at the bottom surface of the ice making cell 320a may be disposed to have the same height. In this case, a line connecting the transparent ice heater <NUM> is a horizontal line, and a line extending in a direction perpendicular to the horizontal line serves as a reference for the unit height of the water of the ice making cell 320a. In the case of <FIG>, ice is made from the uppermost side of the ice making cell 320a and then is grown.

On the other hand, as shown in <FIG>, the transparent ice heater <NUM> at the bottom surface of the ice making cell 320a may be disposed to have different heights. In this case, since heat is supplied to the ice making cell 320a at different heights of the ice making cell 320a, ice is made with a pattern different from that of <FIG>.

For example, in <FIG>, ice may be made at a position spaced apart from the uppermost side to the left side of the ice making cell 320a, and the ice may be grown to a right lower side at which the transparent ice heater <NUM> is disposed.

Accordingly, in <FIG>, a line (reference line) perpendicular to the line connecting two points of the transparent ice heater <NUM> serves as a reference for the unit height of water of the ice making cell 320a. The reference line of <FIG> is inclined at a predetermined angle from the vertical line.

<FIG> illustrates a unit height division of water and an output amount of transparent ice heater per unit height when the transparent ice heater is disposed as shown in <FIG>.

Hereinafter, an example of controlling an output of the transparent ice heater so that the ice making rate is constant for each unit height of water will be described.

Referring to <FIG>, when the ice making cell 320a is formed, for example, in a spherical shape, the mass per unit height of water in the ice making cell 320a increases from the upper side to the lower side to reach the maximum and then decreases again.

For example, the water (or the ice making cell itself) in the spherical ice making cell 320a having a diameter of about <NUM> is divided into nine sections (section A to section I) by <NUM> height (unit height). Here, it is noted that there is no limitation on the size of the unit height and the number of divided sections.

When the water in the ice making cell 320a is divided into unit heights, the height of each section to be divided is equal to the section A to the section H, and the section I is lower than the remaining sections. Alternatively, the unit heights of all divided sections may be the same depending on the diameter of the ice making cell 320a and the number of divided sections,.

Among the many sections, the section E is a section in which the mass of unit height of water is maximum. For example, in the section in which the mass per unit height of water is maximum, when the ice making cell 320a has spherical shape, a diameter of the ice making cell 320a, a horizontal cross-sectional area of the ice making cell 320a, or a circumference of the ice may be maximum.

As described above, when assuming that the cooling power of the cold air supply part <NUM> is constant, and the output of the transparent ice heater <NUM> is constant, the ice making rate in section E is the lowest, the ice making rate in the sections A and I is the fastest.

In this case, since the ice making rate varies for the height, the transparency of the ice may vary for the height. In a specific section, the ice making rate may be too fast to contain bubbles, thereby lowering the transparency.

Therefore, in this embodiment, the output of the transparent ice heater <NUM> may be controlled so that the ice making rate for each unit height is the same or similar while the bubbles move from the portion at which ice is made to the water in the ice making process.

Specifically, since the mass of the section E is the largest, the output W5 of the transparent ice heater <NUM> in the section E may be set to a minimum value. Since the volume of the section D is less than that of the section E, the volume of the ice may be reduced as the volume decreases, and thus it is necessary to delay the ice making rate. Thus, an output W6 of the transparent ice heater <NUM> in the section D may be set to a value greater than an output W5 of the transparent ice heater <NUM> in the section E.

Since the volume in the section C is less than that in the section D by the same reason, an output W3 of the transparent ice heater <NUM> in the section C may be set to a value greater than the output W4 of the transparent ice heater <NUM> in the section D. Since the volume in the section B is less than that in the section C, an output W2 of the transparent ice heater <NUM> in the section B may be set to a value greater than the output W3 of the transparent ice heater <NUM> in the section C. Since the volume in the section A is less than that in the section B, an output W1 of the transparent ice heater <NUM> in the section A may be set to a value greater than the output W2 of the transparent ice heater <NUM> in the section B.

For the same reason, since the mass per unit height decreases toward the lower side in the section E, the output of the transparent ice heater <NUM> may increase as the lower side in the section E (see W6, W7, W8, and W9).

Thus, according to an output variation pattern of the transparent ice heater <NUM>, the output of the transparent ice heater <NUM> is gradually reduced from the first section to the intermediate section after the transparent ice heater <NUM> is initially turned on.

The output of the transparent ice heater <NUM> may be minimum in the intermediate section in which the mass of unit height of water is minimum. The output of the transparent ice heater <NUM> may again increase step by step from the next section of the intermediate section.

The output of the transparent ice heater <NUM> in two adjacent sections may be set to be the same according to the type or mass of the made ice. For example, the output of section C and section D may be the same. That is, the output of the transparent ice heater <NUM> may be the same in at least two sections.

Alternatively, the output of the transparent ice heater <NUM> may be set to the minimum in sections other than the section in which the mass per unit height is the smallest.

For example, the output of the transparent ice heater <NUM> in the section D or the section F may be minimum. The output of the transparent ice heater <NUM> in the section E may be equal to or greater than the minimum output.

In summary, in this embodiment, the output of the transparent ice heater <NUM> may have a maximum initial output. In the ice making process, the output of the transparent ice heater <NUM> may be reduced to the minimum output of the transparent ice heater <NUM>.

The output of the transparent ice heater <NUM> may be gradually reduced in each section, or the output may be maintained in at least two sections. The output of the transparent ice heater <NUM> may increase from the minimum output to the end output. The end output may be the same as or different from the initial output. In addition, the output of the transparent ice heater <NUM> may incrementally increase in each section from the minimum output to the end output, or the output may be maintained in at least two sections.

Alternatively, the output of the transparent ice heater <NUM> may be an end output in a section before the last section among a plurality of sections. In this case, the output of the transparent ice heater <NUM> may be maintained as an end output in the last section. That is, after the output of the transparent ice heater <NUM> becomes the end output, the end output may be maintained until the last section.

As the ice making is performed, an amount of ice existing in the ice making cell 320a may decrease. Thus, when the transparent ice heater <NUM> continues to increase until the output reaches the last section, the heat supplied to the ice making cell 320a may be reduced. As a result, excessive water may exist in the ice making cell 320a even after the end of the last section.

Therefore, the output of the transparent ice heater <NUM> may be maintained as the end output in at least two sections including the last section.

The transparency of the ice may be uniform for each unit height, and the bubbles may be collected in the lowermost section by the output control of the transparent ice heater <NUM>. Thus, when viewed on the ice as a whole, the bubbles may be collected in the localized portion, and the remaining portion may become totally transparent.

As described above, even if the ice making cell 320a does not have the spherical shape, the transparent ice may be made when the output of the transparent ice heater <NUM> varies according to the mass for each unit height of water in the ice making cell 320a.

The heating amount of the transparent ice heater <NUM> when the mass for each unit height of water is large may be less than that of the transparent ice heater <NUM> when the mass for each 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 vary so as to be inversely proportional to the mass per unit height of water.

Also, it is possible to make the transparent ice by varying the cooling power of the cold air supply part <NUM> according to the mass per unit height of water.

For example, when the mass per unit height of water is large, the cold force of the cold air supply part <NUM> may increase, and when the mass per unit height is small, the cold force 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 vary to be proportional to the mass per unit height of water.

Referring to the variable cooling power pattern of the cold air supply part <NUM> in the case of making the spherical ice, the cooling power of the cold air supply part <NUM> from the initial section to the intermediate section during the ice making process may gradually increase.

The cooling power of the cold air supply part <NUM> may be maximum in the intermediate section in which the mass for each unit height of water is minimum. The cooling power of the cold air supply part <NUM> may be gradually reduced again from the next section of the intermediate section.

Alternatively, the transparent ice may be made 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 for each unit height of water.

For example, the heating power of the transparent ice heater <NUM> may vary so that the cooling power of the cold air supply part <NUM> is proportional to the mass per unit height of water and inversely proportional to the mass for each unit height of water.

According to this embodiment, when 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 per unit height of water, the ice making rate per unit height of water may be substantially the same or may be maintained within a predetermined range.

The controller <NUM> may determine whether the ice making is completed based on the temperature sensed by the second temperature sensor <NUM> (S8). When it is determined that the ice making is completed, the controller <NUM> may turn off the transparent ice heater <NUM> (S9).

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

In this case, since a distance between the second temperature sensor <NUM> and each ice making cell 320a is different, in order to determine that the ice making is completed in all the ice making cells 320a, the controller <NUM> may perform the ice separation after a certain amount of time, at which it is determined that ice making is completed, has passed 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, the controller <NUM> operates one or more of the ice separation heater <NUM> and the transparent ice heater <NUM> (S10).

When at least one of the ice separation heater <NUM> or the transparent ice heater <NUM> is turned on, heat of the heater is transferred to at least one of the first tray <NUM> or the second tray <NUM> so that the ice may be separated from the surfaces (inner surfaces) of one or more of the first tray <NUM> and the second tray <NUM>.

Also, the heat of the heaters <NUM> and <NUM> is transferred to the contact surface of the first tray <NUM> and the second tray <NUM>, and thus, the lower surface 321d of the first tray <NUM> and the upper surface 381a of the second tray <NUM> may be in a state capable of being separated from each other.

When at least one of the ice separation heater <NUM> and the transparent ice heater <NUM> operate for a predetermined time, or when the temperature sensed by the second temperature sensor <NUM> is equal to or higher than an off reference temperature, the controller <NUM> is turned off the heaters <NUM> and <NUM>, which are turned on (S10).

Although not limited, the turn-off reference temperature may be set to above zero temperature.

The controller <NUM> operates the driver <NUM> to allow the second tray <NUM> to move in the forward direction (S11).

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

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>, and the extension part <NUM> passes through the communication hole 321e to press the ice in the ice making cell 320a.

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

For another example, even when the heat of the heater is applied to the first tray <NUM>, the ice may not be separated from the surface of the first tray <NUM>.

Therefore, when the second tray <NUM> moves in the forward direction, there is possibility that the ice is separated from the second tray <NUM> in a state in which the ice contacts 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 may press the ice contacting the first tray <NUM>, and thus, the ice may be separated from the tray <NUM>.

The ice separated from the first tray <NUM> may be supported by the second tray <NUM> again.

When the ice moves together with the second tray <NUM> while the ice is supported by the second tray <NUM>, the ice may be separated from the tray <NUM> by its own weight even if no external force is applied to the second tray <NUM>.

While the second tray <NUM> moves, even if the ice does not fall from the second tray <NUM> by its own weight, when the second pusher <NUM> presses the second tray <NUM> as illustrated in <FIG>, the ice may be separated from the second tray <NUM> to fall downward.

Specifically, as illustrated in <FIG>, while the second tray <NUM> moves, the second tray <NUM> may contact the extension part <NUM> of the second pusher <NUM>. When the second tray <NUM> continuously moves in the forward direction, the extension part <NUM> may press the second tray <NUM> to deform the second tray <NUM>. Thus, the pressing force of the extension part <NUM> may be transferred to the ice so that the ice is separated from the surface of the second tray <NUM>. The ice separated from the surface of the second tray <NUM> may drop downward and be stored in the ice bin <NUM>.

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

Whether the ice bin <NUM> is full may be detected while the second tray <NUM> moves from the ice making position to the ice separation position.

For example, the full ice detection lever <NUM> rotates together with the second tray <NUM>, and the rotation of the full ice detection lever <NUM> is interrupted by ice while the full ice detection lever <NUM> rotates. In this case, it may be determined that the ice bin <NUM> is in a full ice state. On the other hand, if the rotation of the full ice detection lever <NUM> is not interfered with the ice while the full ice detection lever <NUM> rotates, it may be determined that the ice bin <NUM> is not in the ice state.

After the ice is separated from the second tray <NUM>, the controller <NUM> controls the driver <NUM> to allow the second tray <NUM> to move in the reverse direction (S11). Then, the second tray <NUM> moves from the ice separation position to 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> while the second tray <NUM> moves in the reverse direction, the deformed second tray <NUM> may be restored to its original shape.

In the reverse movement of the second tray <NUM>, the moving force of the second tray <NUM> is transmitted to the first pusher <NUM> by the pusher link <NUM>, and thus, the first pusher <NUM> ascends, and the extension part <NUM> is removed from the ice making cell 320a.

<FIG> is a view for explaining a method for controlling a refrigerator when a heat transfer amount between cold air and water varies in an ice making process, and <FIG> is a graph showing a change in output of a transparent ice heater according to an increase/decrease in heat transfer amount of cold air and water. <FIG> is a view illustrating an output for each control process of a transparent ice heater in an ice making process.

Referring to <FIG>, cooling power of the cold air supply part <NUM> may be determined corresponding to 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>.

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

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

In this embodiment, the heating amount 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. The magnitude of the reference heating amount per unit height of water is different.

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

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

For example, when a target temperature of the freezing compartment <NUM> is lowered, an operation mode of the freezing compartment <NUM> is changed from a normal mode to a quick cooling mode, an output of at least one of the compressor or the fan increases, or an opening degree increases, the cooling power of the cold air supply part <NUM> may increase. In addition, when the refrigerator door is opened or the defrosting operation is performed, air having a temperature higher than the temperature of the cold air in the freezing compartment <NUM> may be supplied to the freezing compartment <NUM>.

On the other hand, when the target temperature of the freezer compartment <NUM> increases, the operation mode of the freezing compartment <NUM> is changed from the quick cooling mode to the normal mode, the output of at least one of the compressor or the fan decreases, or the opening degree of the refrigerant valve decreases, the cooling power of the cold air supply part <NUM> may decrease. When the cooling power of the cold air supply part <NUM> increases, the temperature of the cold air around the ice maker <NUM> is lowered to increase in ice making rate.

On the other hand, if the cooling power of the cold air supply part <NUM> decreases, the temperature of the cold air around the ice maker <NUM> increases, the ice making rate decreases, and also, the ice making time increases.

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

On the other hand, when the amount of heat transfer between the cold and the water decreases, the heating amount of transparent ice heater <NUM> may be controlled to decrease.

In this embodiment, when the ice making rate is maintained within the predetermined range, the ice making rate is less than the rate at which the bubbles move in the portion at which the ice is made, and no bubbles exist in the portion at which the ice is made.

When the cooling power of the cold air supply part <NUM> increases, the heating amount of transparent ice heater <NUM> may increase. On the other hand, when the cooling power of the cold air supply part <NUM> decreases, the heating amount of transparent ice heater <NUM> may decrease.

Hereinafter, the control of the transparent ice heater <NUM> when the heat transfer amount of the cold air and water is maintained constant during the ice making process will be described. As an example, as a case in which the temperature of the freezing compartment <NUM> is relatively weak, a case in which the temperature of the freezing compartment <NUM> is a first temperature value will be described.

A non-claimed method for controlling the transparent ice heater for making transparent ice may include a basic heating process and an additional heating process. An additional heating process may be performed after the end of the basic heating process. Hereinafter, an example of controlling the output of the transparent ice heater dsfs the heating amounts of the transparent ice heater will be described. The method for controlling the output of the transparent ice heater may be applied in the same manner as or in the similar manner to the method for controlling the duty of the transparent ice heater.

The basic heating process may include a plurality of processes. In <FIG>, as an example, it is shown that the basic heating process includes ten processes.

In each of the plurality of processes, the output of the transparent ice heater <NUM> is predetermined. In each process, the output of the transparent ice heater <NUM> is determined based on the mass per unit height of water in the ice making cell 320a.

As described above, when the on condition of the transparent ice heater <NUM> is satisfied, the first process of the basic heating process may be started. In the first process, the output of the transparent ice heater <NUM> may be A1.

When the first process starts and the first set time T1 elapses, the second process may start. At least one of the plurality of processes may be performed for the first set time T1. For example, the time at which each of the plurality of processes is performed may be the same as the first set time T1. That is, when each process starts and the first set time T1 elapses, each process may be ended. Accordingly, the output of the transparent ice heater <NUM> may be variably controlled over time.

As another example, even if the tenth process, which is the last process among the plurality of processes, starts and the first set time T1 elapses, the tenth process may not be immediately ended. In this case, when the temperature sensed by the second temperature sensor <NUM> reaches a limit temperature, the tenth process may be ended.

The limit temperature may be set to a sub-zero temperature. When the door is opened during the ice making process, or when the defrost heater is operated, or when heat having a temperature higher than the temperature of the freezing compartment is provided to the freezing compartment, the temperature of the freezing compartment <NUM> may increase.

When an additional ice maker and ice bin are provided in the door, the ice maker provided in the door may receive cold air for cooling the freezing compartment <NUM> and make ice. When full ice is detected in the ice bin provided in the door, the cooling power of the cold air supply part <NUM> may be less than the cooling power before the detection of the full ice.

When the output of the transparent ice heater <NUM> is controlled according to time in the basic heating process as in this embodiment, the transparent ice heater <NUM> operates according to the output at each process, regardless of the increase in the temperature of the freezing compartment <NUM> or the decrease in the cooling power of the cold air supply part <NUM>. Thus, there is a possibility that water does not phase-change into ice in the ice making cell 320a. That is, even if the tenth process in the basic heating process is performed for the first set time T1, the temperature sensed by the second temperature sensor <NUM> may be higher than the limit temperature.

Therefore, to reduce the amount of unfrozen water in the ice making cell 320a after the end of the tenth process, the tenth process may be ended when the first set time T1 elapses and the temperature sensed by the second temperature sensor <NUM> reaches the limit temperature.

After the basic heating process is ended, an additional heating process is performed.

When the ice maker <NUM> includes a plurality of ice making cells 320a, the amount of heat transfer between water and cold air in each ice making cell 320a is not constant. Thus, the speed at which ice is made in the plurality of ice making cells 320a may be different from each other.

For example, after the basic heating process is ended, water may completely change into ice in some ice making cells 320a among the plurality of ice making cells 320a, but some of the water may not phase-change into ice in other ice making cells 320a. In this state, if the ice breaking process is performed after the end of the basic heating process, there may be a problem in that water present in the ice making cell 320a falls downward. Accordingly, the additional heating process may be performed after the basic heating process is ended, so that transparent ice may be made in each of the plurality of ice making cells 320a.

The additional heating process may include a process (an eleventh process or a first additional process) of operating the transparent ice heater <NUM> with a set output for a second set time T2.

Since heat transfer between the cold air and the water occurs even in the additional heating process, the transparent ice heater <NUM> may operate with a set output A11 to make transparent ice.

The output A11 of the transparent ice heater <NUM> in the eleventh process may be the same as the output of the transparent ice heater <NUM> in one of the plurality of processes of the basic heating process.

For example, the output A11 of the transparent ice heater <NUM> may be the same as the minimum output of the transparent ice heater <NUM> in the basic heating process. The second set time T2 may be longer than the first set time T1.

When the eleventh process is performed, even if the amount of water supplied to the ice making cell 320a is smaller than a set amount, the water may phase-change into ice in the ice making cell 320a.

Even if the amount of water supplied to the ice making cell 320a is smaller than the set amount, the output of the transparent ice heater <NUM> may be set as a predetermined reference output.

In this case, the amount of heat supplied from the transparent ice heater <NUM> is large compared to the mass of water in the ice making cell 320a during the ice making process. Accordingly, even if the basic heating process is ended due to the slowing of the ice making rate in the ice making cell 320a, there is a possibility that water will exist in the ice making cell 320a.

In such a situation, when the eleventh process is performed, heat is transferred to water and cold air while the minimum amount of heat is supplied to the ice making cell 320a, so that water may be completely phase-changed into ice in the ice making cell 320a.

The additional heating process may further include a process (a twelfth process or a second additional process) of operating the transparent ice heater <NUM> with a set output A12 after the eleventh process. The output A12 of the transparent ice heater <NUM> in the twelfth process may be the same as or different from the output A11 of the transparent ice heater <NUM> in the eleventh process. When the third set time T3 elapses or the temperature sensed by the second temperature sensor <NUM> before the elapse of the third set time T3 reaches the end reference temperature, the twelfth process may be ended. The third set time T3 may be equal to or shorter than the second set time T2.

When the temperature sensed by the second temperature sensor <NUM> reaches the end reference temperature, the twelfth process is ended, and as a result, the additional heating process may be ended. When the additional heating process is ended, the ice separation process may be performed.

The additional heating process may further include a process (a thirteenth process or a third additional process) of operating the transparent ice heater <NUM> with a set output A13 after the twelfth process. The thirteenth process may be performed when the twelfth process is performed for the third set time T3 but the temperature sensed by the second temperature sensor <NUM> does not reach the end reference temperature. The end reference temperature may be set to a temperature lower than the limit temperature, and may be a reference temperature for determining that ice is completely made in the ice making cell 320a.

As described above, when the door is opened during the ice making process, or when the defrost heater is operated, or when heat having a temperature higher than the temperature of the freezing compartment <NUM> is provided to the freezing compartment <NUM>, the temperature of the freezing compartment <NUM> may increase. When full ice is detected in the ice bin provided in the door, the cooling power of the cold air supply part <NUM> for supplying cold air to the freezing compartment <NUM> may be reduced.

At this time, when the temperature increasing width of the freezing compartment <NUM> is large or the cooling power of the cold air supply part <NUM> decreases, ice may not be completely made in the ice making cell 320a even after the basic heating process and the eleventh and twelfth processes are performed.

Accordingly, after the end of the twelfth process, the transparent ice heater <NUM> may operate with a set output A13 so that water remaining in the ice making cell 320a can be phase-changed into ice.

The output A13 of the transparent ice heater <NUM> in the thirteenth process may be equal to or less than the output A12 of the transparent ice heater <NUM> in the twelfth process. The output A13 of the transparent ice heater <NUM> in the thirteenth process may be less than the minimum output of the transparent ice heater <NUM> in the basic heating process. When a fourth set time T4 elapses or the temperature sensed by the second temperature sensor <NUM> before the fourth set time T4 reaches the end reference temperature, the thirteenth process may be ended. The fourth set time T4 may be equal to or different from the third set time T3.

When the temperature sensed by the second temperature sensor <NUM> reaches the end reference temperature, the thirteenth process is ended, and as a result, the additional heating process may be ended. When the additional heating process is ended, the ice separation process may be performed.

The additional heating process may further include a process (a fourteenth process or a fourth additional process) of operating the transparent ice heater <NUM> with a set output A14 after the thirteenth process. The fourteenth process may be performed when the thirteenth process is performed for the fourth set time T4 but the temperature sensed by the second temperature sensor <NUM> does not reach the end reference temperature. The output A14 of the transparent ice heater <NUM> in the fourteenth process may be less than the output A13 of the transparent ice heater <NUM> in the thirteenth process. When a fifth set time T5 elapses or the temperature sensed by the second temperature sensor <NUM> before the fifth set time T5 reaches the end reference temperature, the fourteenth process may be ended. The fifth set time T5 may be equal to or different from the fourth set time T4.

When the temperature sensed by the second temperature sensor <NUM> reaches the end reference temperature, the fourteenth process is ended, and as a result, the additional heating process may be ended. When the additional heating process is ended, the ice separation process may be performed.

The additional heating process may further include a process (a fifteenth process or a fifth additional process) of operating the transparent ice heater <NUM> with a set output A15 after the fourteenth process. The fifteenth process may be performed when the fourteenth process is performed for the fifth set time T5 but the temperature sensed by the second temperature sensor <NUM> does not reach the end reference temperature. The output A15 of the transparent ice heater <NUM> in the fifteenth process may be less than the output A14 of the transparent ice heater <NUM> in the fourteenth process. The output A14 of the transparent ice heater <NUM> in the fifteenth process may be set to <NUM>/<NUM> of the output A14 of the transparent ice heater <NUM> in the fourteenth process.

When the sixth set time T6 elapses or the temperature sensed by the second temperature sensor <NUM> before the elapse of the sixth set time T6 reaches the end reference temperature, the fifteenth process may be ended. The sixth set time T6 may be longer than the first to fifth set times T1 to T5.

The maximum output of the transparent ice heater <NUM> in the additional heating process is less than the maximum output of the transparent ice heater <NUM> in the basic heating process. The minimum output of the transparent ice heater <NUM> in the additional heating process is less than the minimum output of the transparent ice heater <NUM> in the basic heating process.

When the fifteenth process is ended, the additional heating process may be finally ended.

Hereinafter, the case in which the target temperature of the freezing compartment <NUM> varies will be described with an example.

The controller <NUM> may control the output of the transparent ice heater <NUM> so that the ice making rate may be maintained within the predetermined range regardless of the target temperature of the freezing compartment <NUM>.

For example, the ice making may be started (S4), and a change in heat transfer amount of cold and water may be detected (S31). For example, it may be sensed that the target temperature of the freezing compartment <NUM> is changed through an input part (not shown).

The controller <NUM> may determine whether the heat transfer amount of cold and water increases (S32). For example, the controller <NUM> may determine whether the target temperature increases.

As the result of the determination in the process S32, when the target temperature of the freezing compartment <NUM> increases, the controller <NUM> may decrease the reference heating amount of transparent ice heater <NUM> that is predetermined in each of the current section and the remaining sections.

The variable control of the heating amount of the transparent ice heater <NUM> may be normally performed until the ice making is completed (S35).

On the other hand, if the target temperature of the freezing compartment <NUM> decreases, the controller <NUM> may increase the reference heating amount of transparent ice heater <NUM> that is predetermined in each of the current section and the remaining sections. The variable control of the heating amount of the transparent ice heater <NUM> may be normally performed until the ice making is completed (S35).

In this embodiment, the reference heating mount that increases or decreases may be predetermined and then stored in a memory.

When ice making starts while the target temperature of the freezing compartment <NUM> is set to medium, or when the target temperature of the freezing compartment <NUM> changes from weak to medium during the ice making process, the output of the transparent ice heater <NUM> operates with an output determined when the target temperature of the freezing compartment <NUM> is medium (when the temperature of the freezing compartment <NUM> is a second temperature value lower than a first temperature value).

For example, in the basic heating process, the output of the transparent ice heater <NUM> may be controlled to B1 to B10.

In addition, the additional heating process may be performed after the basic heating process.

The contents of the set times (T1 to T6) and the end reference temperature described above may be equally applied even when the target temperature of the freezing compartment <NUM> is medium.

The outputs B11 to B15 of the transparent ice heater <NUM> in the eleventh to fifteenth processes when the target temperature of the freezing compartment <NUM> is medium may be greater than the outputs A11 to A15 of the transparent ice heater <NUM> in the eleventh to fifteenth processes.

The output B11 of the transparent ice heater <NUM> in the eleventh process may be equal to the output of the transparent ice heater <NUM> in one of the plurality of processes of the basic heating process.

For example, the output B11 of the transparent ice heater <NUM> in the eleventh process may be equal to the minimum output in the basic heating process. The output B12 of the transparent ice heater <NUM> in the twelfth process may be equal to or different from the output B11 of the transparent ice heater <NUM> in the eleventh process. The output B13 of the transparent ice heater <NUM> in the thirteenth process may be equal to or different from the output B11 of the transparent ice heater <NUM> in the twelfth process.

The output B13 of the transparent ice heater <NUM> in the thirteenth process when the target temperature of the freezing compartment <NUM> is medium may be equal to or different from the maximum output of the transparent ice heater <NUM> in the basic heating process when the target temperature of the freezing compartment <NUM> is weak.

The output B14 of the transparent ice heater <NUM> in the fourteenth process may be less than the output B13 of the transparent ice heater <NUM> in the thirteenth process.

The output B14 of the transparent ice heater <NUM> in the fourteenth process when the target temperature of the freezing compartment <NUM> is medium may be equal to or different from the maximum output of the transparent ice heater <NUM> in the basic heating process when the target temperature of the freezing compartment <NUM> is weak.

The output B15 of the transparent ice heater <NUM> in the fourteenth process may be less than the output B14 of the transparent ice heater <NUM> in the fourteenth process. The output B15 of the transparent ice heater <NUM> in the fifteenth process may be set to <NUM>/<NUM> of the output B14 of the transparent ice heater <NUM> in the fourteenth process.

When ice making starts while the target temperature of the freezing compartment <NUM> is set to strong, or when the target temperature of the freezing compartment <NUM> changes to strong during the ice making process, the output of the transparent ice heater <NUM> operates with an output determined when the target temperature of the freezing compartment <NUM> is strong (when the temperature of the freezing compartment <NUM> is a third temperature value lower than a second temperature value).

For example, in the basic heating process, the output of the transparent ice heater <NUM> may be controlled to C1 to C10. In addition, the additional heating process may be performed after the basic heating process.

The contents of the set times (T1 to T6) and the end reference temperature described above may be equally applied even when the target temperature of the freezing compartment <NUM> is strong.

The outputs C11 to C15 of the transparent ice heater <NUM> in the eleventh to fifteenth processes when the target temperature of the freezing compartment <NUM> is strong may be greater than the outputs B11 to B15 of the transparent ice heater <NUM> in the eleventh to fifteenth processes when the target temperature of the freezing compartment <NUM> is medium.

The output C11 of the transparent ice heater <NUM> in the eleventh process may be equal to the output of the transparent ice heater <NUM> in one of the plurality of processes of the basic heating process.

For example, the output C11 of the transparent ice heater <NUM> in the eleventh process may be equal to the minimum output in the basic heating process. The output C12 of the transparent ice heater <NUM> in the twelfth process may be equal to or different from the output C11 of the transparent ice heater <NUM> in the eleventh process. The output C13 of the transparent ice heater <NUM> in the thirteenth process may be equal to or different from the output C11 of the transparent ice heater <NUM> in the twelfth process.

The output C13 of the transparent ice heater <NUM> in the thirteenth process when the target temperature of the freezing compartment <NUM> is strong may be equal to or different from the maximum output of the transparent ice heater <NUM> in the basic heating process when the target temperature of the freezing compartment <NUM> is strong.

The output C14 of the transparent ice heater <NUM> in the fourteenth process may be less than the output C13 of the transparent ice heater <NUM> in the thirteenth process.

The output C14 of the transparent ice heater <NUM> in the fourteenth process when the target temperature of the freezing compartment <NUM> is strong may be equal to or different from the maximum output of the transparent ice heater <NUM> in the basic heating process when the target temperature of the freezing compartment <NUM> is medium.

The output C15 of the transparent ice heater <NUM> in the fourteenth process may be less than the output C14 of the transparent ice heater <NUM> in the fourteenth process. The output C15 of the transparent ice heater <NUM> in the fifteenth process may be set to <NUM>/<NUM> of the output C14 of the transparent ice heater <NUM> in the fourteenth process.

In the above embodiment, the additional heating process may include only the eleventh and twelfth processes, or may include only the thirteenth to fifteenth processes.

When the additional heating process includes only the eleventh and twelfth processes, the additional heating process may be ended while the output of the transparent ice heater <NUM> is maintained constant in the additional heating process.

For example, when the additional heating process does not include the eleventh and twelfth processes, the thirteenth process may be performed immediately after the basic heating process is ended. In this case, the thirteenth to fifteenth processes may be referred to as first to third additional processes. Of course, the fourteenth or fifteenth process may not be performed according to the temperature sensed by the second temperature sensor.

Alternatively, the additional heating process may include at least the eleventh process and the thirteenth process.

According to this embodiment, the reference heating amount for each section of the transparent ice heater increases or decreases in response to the change in the heat transfer amount of cold and water, and thus, the ice making rate may be maintained within the predetermined range, thereby realizing the uniform transparency for each unit height of the ice.

In the additional heating process, the output of the transparent ice heater <NUM> may vary according to the space temperature of the space (for example, the indoor space) in which the refrigerator is disposed in the basic heating process.

For example, if the space temperature is high, the condensing temperature of the condenser that exchanges heat with the air in the space is high, the operating time of the compressor is increased, and the cooling power of the compressor is increased. Thus, the temperature of the cold air supplied to the ice maker <NUM> is reduced. Accordingly, the output of the transparent ice heater <NUM> may be increased in response to the reduction in the temperature of the cold air supplied to the ice maker <NUM>.

In response to the increase in the output of the transparent ice heater <NUM> in the basic heating process, the controller <NUM> may perform control so that the output of the transparent ice heater <NUM> in the additional heating process is greater compared to the case in which the temperature of the space in which the refrigerator is disposed in the basic heating process is low.

In addition, the defrosting operation may be performed in the additional heating process. The defrosting heater may be turned on in the defrosting operation. When the defrosting heater is turned on, the temperature of the storage chamber may be increased by the heat of the defrosting heater. When the temperature of the storage chamber increases, the output of the transparent ice heater <NUM> may decrease. The output of the transparent ice heater <NUM> may be determined in the additional heating process according to the length of the defrosting time.

The controller <NUM> may perform control so that the output of the transparent ice heater <NUM> in the additional heating process is smaller when the defrosting operation time in the basic heating process is long than when the defrosting operation time in the basic heating process is short.

In addition, the refrigerator door may be opened or closed in the basic heating process. When the refrigerator door is opened, air outside the refrigerator may flow into the storage chamber, and thus the temperature of the storage chamber may increase. As the opening time of the refrigerator door is longer, the temperature increase width of the storage chamber is greater. In the basic heating process, the controller <NUM> may reduce the output of the transparent ice heater <NUM> in response to the decrease in the heat transfer amount of cold air and water due to the opening of the refrigerator door. In addition, the controller <NUM> may perform control so that the output of the transparent ice heater <NUM> in the additional heating process is smaller when the opening time of the refrigerator door in the basic heating process is long than when the opening time of the refrigerator door in the basic heating process is short.

On the other hand, the operation of the transparent ice heater <NUM> may be controlled for ice separation.

For example, after the basic heating process is ended, the controller <NUM> may turn on the transparent ice heater <NUM> so as to move the second tray <NUM>. In addition, the ice separation heater <NUM> may be turned on ice is separated from the first tray <NUM> after the basic heating process is ended, and the first tray <NUM> and the second tray <NUM> are easily separated.

When the turn-off condition of the ice separation heater <NUM> and the transparent ice heater <NUM> is satisfied, the ice separation heater <NUM> and the transparent ice heater <NUM> may be turned off. A portion of the ice in the ice making cell 320a may be melted by the heat of the heaters <NUM> and <NUM>.

The ice separation heater <NUM> and the transparent ice heater <NUM> may be turned off to prevent the ice melted in the ice making cell 320a during the ice separation process from falling downward, and the second tray <NUM> may be moved to the ice separation position after the set time elapses.

According to another embodiment, the output of the transparent ice heater <NUM> in the additional heating process may be determined based on the temperature of the refrigerating compartment in the basic heating process.

Depending on the type of refrigerator, the refrigerator may supply cold air to the freezing compartment by using one evaporator, and cold air of the freezing compartment may flow into the refrigerating compartment that controls the damper provided in the duct. Other types of refrigerators may supply cold air to the freezing compartment and the refrigerating compartment by using the freezing compartment evaporator and the refrigerating compartment evaporator, respectively. However, the freezing compartment evaporator and the refrigerating compartment evaporator may be alternately operated.

In any case, when the target temperature of the refrigerating compartment is low, the supply of cold air to the refrigerating compartment increases. Thus, the supply of cold air to the freezing compartment is relatively reduced. In this case, the temperature of the freezing compartment increases. In response to the increase in the temperature of the freezing compartment, the output of the transparent ice heater <NUM> may be controlled to decrease in the basic heating process. On the other hand, when the target temperature of the refrigerating compartment is high, the supply of cold air to the freezing compartment is increased, and thus the output of the transparent ice heater <NUM> may be controlled to increase in the basic heating process.

The controller <NUM> may perform control so that the output of the transparent ice heater <NUM> in the additional heating process is greater when the target temperature of the refrigerating compartment in the basic heating process is high than when the target temperature of the refrigerating compartment in the basic heating process is low.

Claim 1:
A refrigerator comprising:
a storage chamber configured to store food;
a cooler (<NUM>) configured to supply cold into the storage chamber;
an ice maker (<NUM>) comprising an ice making cell (320a), which is a space in which water is phase-changed into ice by the cold;
a transparent ice heater (<NUM>) configured to supply heat into the ice making cell (320a); and
a controller (<NUM>) configured to control the transparent ice heater (<NUM>),
wherein the controller (<NUM>) controls the transparent ice heater (<NUM>) to operate in at least partial section while the cooler (<NUM>) supplies the cold so that bubbles dissolved in the water within the ice making cell (320a) move from a portion, at which the ice is made, toward the water that is in a liquid state to make transparent ice,
a process for controlling the transparent ice heater (<NUM>) comprises a basic heating process and an additional heating process that is performed after the basic heating process,
in the basic heating process, the controller (<NUM>) performs control so that a heating amount of the transparent ice heater (<NUM>) varies according to a mass per unit height of the water in the ice making cell (320a), and
in at least partial section of the additional heating process, the controller (<NUM>) controls the transparent ice heater (<NUM>) to operate with a heating amount that is equal to or less than a heating amount of the transparent ice heater (<NUM>) in the basic heating process.