Patent Description:
In general, refrigerators are home appliances for storing food at a low temperature in a storage space 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 separates the made ice from the ice tray in a heating manner or twisting manner.

The ice maker through which water is automatically supplied, and the ice automatically separated may be, for example, 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> that is a prior art document.

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

In the case of the prior art document, the ice maker further includes a heat separation heater for heating the upper cell to separate ice. However, there is a problem in that there is no means for detecting a change in temperature due to cold air for cooling and heat transferred from the ice separation heater.

<CIT> presents an ice maker that includes an upper tray that includes a plurality of upper cells that each have a hemispherical shape and an ice making tube disposed at outer circumferential surfaces of the upper cells and configured to cool each of the upper cells. The ice maker also includes a lower tray that includes a plurality of lower cells that each have a hemispherical shape. The lower tray is rotatably connected to the upper tray. The ice maker further includes a rotation shaft connected to a rear end of the lower tray and a rear end of the upper tray, and configured to rotate the lower tray with respect to the upper tray.

<CIT> discloses a refrigerator that includes an ice making tray, a cooling system, a stirrer, at least a portion of which is submerged in the ice making tray, a stirring motor coupled to the stirrer, and a controller storing instructions and configured to execute the stored instructions to control the stirring motor to drive the stirrer while controlling the cooling system to cool water stored in the ice making tray. While the cooling system cools the water stored in the ice making tray, the stirrer stirs the water stored in the ice making tray.

Further relevant prior art documents are <CIT> and <CIT>.

A refrigerator according to claim <NUM> includes: a first tray configured to define one portion of an ice making cell that is a space in which water is phase-changed into ice by cold air; a second tray configured to define the other portion of the ice making cell; a water supply part configured to supply water to the ice making cell; and a temperature sensor configured to detect a temperature of the water or the ice of the ice making cell, wherein the temperature sensor is in contact with at least one of the first tray or the second tray.

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

The controller controls a cold air supply part to supply the cold air to the ice making cell after the second tray moves to an ice making position after the water supply to the ice making cell is completed. The controller controls the second tray to move to an ice separation position in a forward direction so as to take ice out of the ice making cell after the ice is completely generated in the ice making cell. The controller controls the second tray to move from an ice separation position to a water supply position in a reverse direction after an ice separation is completed so as to supply the water.

At least one of the first tray or the second tray may include a sensor accommodation part in which the temperature sensor is accommodated.

The temperature sensor may be in contact with the fixed tray of the first tray and the second tray.

A heater is disposed at a position adjacent to at least one of the first tray or the second tray. The heater includes an ice separation heater and a transparent ice heater that is turned on in at least partial section while the cold air supply part supplies the cold air so that bubbles dissolved in the water within the ice making cell moves from a portion, at which the ice is generated, toward the water that is in a liquid state to generate transparent ice.

The temperature sensor may be in contact with the tray, which is disposed farthest from the transparent ice heater, of the first tray and the second tray.

The temperature sensor may be in contact with the fixed tray, which have a high temperature change in the ice making process, of the first tray and the second tray.

The ice making cell may be provided in plurality, and at least a portion of the temperature sensor may be disposed between two ice making cells adjacent to each other.

The ice making cell may be provided in plurality, and the temperature sensor may be disposed so that a distance between a cold air hole and the temperature sensor is less than that between a first ice making cell of the plurality of ice making cells, which is disposed farthest from the cold air hole for supplying the cold air by the cold air supply part, and the cold air hole.

The temperature sensor may be disposed to be in contact with the first ice making cell.

The plurality of ice making cells may include a second ice making cell disposed adjacent to the first ice making cell, and at least a portion of the temperature sensor may be disposed between the first ice making cell and the second ice making cell.

The plurality of ice making cells may include a third ice making cell disposed at an opposite side of the first ice making cell based on the second ice making cell, and a distance between a center of the first ice making cell and a center of the second ice making cell may be greater than that between the second ice making cell and a center of the third ice making cell.

The heater includes an ice separation heater configured to supply heat to at least one of the first tray or the second tray in the ice separation process.

The temperature sensor is disposed to be spaced apart from the ice separation heater, and a distance from the temperature sensor to a contact surface between the first tray and the second tray is less than that from the ice separation heater to the contact surface between the first tray and the second tray.

According to the proposed invention, the temperature sensor that detects the temperature of the tray, which is the means for detecting the time point at which the approbate ice making is completed in the operation process of the ice maker to improve the reliability at the time point at which the ice making is completed.

In addition, the temperature sensor may be disposed at the optimal position for measuring a temperature the ice inside the tray without interfering with the electric wire connected to the temperature sensor to prevent the temperature sensor from being broken down.

Hereinafter, some embodiments of the present invention will be described in detail with reference to the accompanying drawings. <FIG> and <FIG> show embodiments being useful for understanding the invention, which are outside the subject-matter of the claims. <FIG> show embodiments according to the present invention, which disclose a refrigerator according to claim <NUM>.

Exemplary embodiments of the present invention will be described below in more detail with reference to the accompanying drawings. It is noted that the same or similar components in the drawings are designated by the same reference numerals as far as possible even if they are shown in different drawings.

<FIG> is a front view of a refrigerator according to an embodiment being useful for understanding the invention, which are outside the subject-matter of the claims.

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

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

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

The door may include a plurality of doors <NUM>, <NUM>, <NUM> for opening and closing the refrigerating compartment <NUM> and the freezing compartment <NUM>. The plurality of doors <NUM>, <NUM>, and <NUM> may include some or all of the doors <NUM> and <NUM> for opening and closing the storage chamber in a rotatable manner and the door <NUM> for opening and closing the storage chamber in a sliding manner.

The freezing compartment <NUM> may be provided to be separated into two spaces even though the freezing compartment <NUM> is opened and closed by one door <NUM>.

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

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

An ice bin <NUM> in which the ice made by the ice maker <NUM> drops 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 the ice maker according to an embodiment, <FIG> is a perspective view illustrating a state in which the 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> so as to show a second temperature sensor installed in the ice maker according to an embodiment of the present invention,.

<FIG> is a cross-sectional view taken along line <NUM>-<NUM> of <FIG> so as to show a second temperature sensor that is in contact with a first tray according to an embodiment of the present invention, and.

<FIG> is a cross-sectional view taken along line <NUM>-<NUM> of <FIG> so as to show a second temperature sensor that is in contact with a second tray according to an embodiment of the present invention.

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

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

The bracket <NUM> may be installed at, for example, the upper wall of the freezing compartment <NUM>. A cold air hole <NUM> through which cold air flows from a cold air supply part <NUM> (see <FIG>) to be described later may be formed at one side of the bracket <NUM>. The water supply part <NUM> may be installed on an upper side of an inner surface of the bracket <NUM>. The water supply part <NUM> may be provided with an opening in each of an upper side and a lower side to guide water, which is supplied to an upper side of the water supply part <NUM>, to a lower side of the water supply part <NUM>. The upper opening of the water supply part <NUM> may be greater than the lower opening to limit a discharge range of water guided downward through the water supply part <NUM>. A water supply pipe through which water is supplied may be installed to the upper side of 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> includes an ice making cell 320a in which water is phase-changed into ice by the cold air.

The ice maker <NUM> includes a first tray <NUM> defining at least a portion of a wall providing the ice making cell 320a and a second tray <NUM> defining at least the other portion of a wall 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> is 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> are in contact with each other, the complete ice making cell see 320a may be defined.

On the other hand, the second tray <NUM> moves with respect to the first tray <NUM> during the ice making process after the ice making is completed, and the second tray <NUM> is 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 defined. 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>, for example, three ice making cells 320a are provided.

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 hemisphere shape or a shape similar to the hemisphere. Also, the second cell 320c may be provided in a hemisphere shape or a shape similar to the hemisphere. 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 an 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 second 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>. For example, the ice separation heater <NUM> may be a wire-type heater. For example, the ice separation 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>. In some 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 bottom surface of the first tray <NUM>.

The first tray case <NUM> may be provided with a guide slot <NUM> which is inclined at an upper side and vertically extended at a lower side thereof. The guide slot <NUM> may be provided in a member extending upward from the first tray case <NUM>.

A guide protrusion <NUM> of the first pusher <NUM> to be described later may be inserted into the guide slot <NUM>. Thus, the guide protrusion <NUM> may be guided along the guide slot <NUM>.

The first pusher <NUM> may include at least one extension part <NUM>. For example, the first pusher <NUM> may include an 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. Accordingly, 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 the 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 a second cell 320c of the second tray <NUM> may be supported by the second tray case <NUM>.

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

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

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

The ice maker <NUM> may furth er 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 controls 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 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 ice 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.

Alternatively, 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.

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

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

A through-hole <NUM> may be defined in an extension part <NUM> extending downward in one side of the first tray case <NUM>. A through-hole <NUM> may be defined in the extension part <NUM> extending in one side of the second tray case <NUM>. 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 'c' 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 an 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 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 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 second tray supporter <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-metallic 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.

The first tray <NUM> may be made of a metal material. In this case, since the coupling force or the attaching force between the first tray <NUM> and the ice is strong, the ice maker <NUM> according to this embodiment includes an ice separation heater <NUM> and may include a 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> includes at least the ice separation heater <NUM>. Although not limited, the first 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>.

Referring to <FIG>, the ice maker <NUM> includes a second temperature sensor <NUM> (or tray temperature sensor) for detecting a temperature of the ice making cell 320a. The second temperature sensor <NUM> senses a temperature of water or ice of the ice making cell 320a.

In detail, the second temperature sensor <NUM> is disposed adjacent to at least one of the first tray <NUM> or the second tray <NUM> to detect a temperature of the tray, thereby indirectly detecting a temperature of water or ice of the ice making cell 320a.

For example, the second temperature sensor <NUM> may be in contact with the first tray <NUM> as illustrated in <FIG> or may be in contact with the second tray <NUM> as illustrated in <FIG>.

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.

For example, 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 a predetermined distance from the first tray <NUM>. For another example, the second temperature sensor <NUM> may be installed in the first tray <NUM> to be in contact with the first tray <NUM>.

Alternatively, when the second temperature sensor <NUM> may be disposed to pass through the first tray <NUM>, the temperature of the water or the temperature of the ice of the ice making cell 320a may be directly detected.

Referring to <FIG>, the first tray <NUM> may further include a sensor accommodation part <NUM> accommodating the second temperature sensor <NUM>. The sensor accommodation part <NUM> may be recessed downward from the case accommodation part 321b.

Here, a bottom surface of the sensor accommodation part <NUM> may be disposed at a position lower than that of the bottom surface of the heater accommodation part 321a to prevent the second temperature sensor <NUM> from interfering with the ice separation heater <NUM> in a state in which the second temperature sensor <NUM> is accommodated in the sensor accommodation part <NUM>. The bottom surface of the sensor accommodation part <NUM> may be disposed closer to the bottom surface 321d of the first tray <NUM> than the bottom surface of the heater accommodation part 321a.

In addition, in a state in which the second temperature sensor <NUM> is accommodated in the sensor accommodation part <NUM>, the second temperature sensor <NUM> may be disposed lower than the plate <NUM> of the first tray <NUM>, or the top surface of the second temperature sensor <NUM> may be in contact with the heater case <NUM>.

At least a portion of the second temperature sensor <NUM> may be in contact with the bottom surface of the sensor accommodation part <NUM>. Although not limited, the second temperature sensor <NUM> may be directly accommodated in the sensor accommodation part <NUM>.

Alternatively, the second temperature sensor <NUM> may be installed in the heater case <NUM>. In this case, when the ice separation heater <NUM> of the heater case <NUM> is accommodated in the heater accommodation part 323a, the second temperature sensor <NUM> may be accommodated in the sensor accommodation part <NUM>.

The sensor accommodation part <NUM> may be disposed between two adjacent ice making cells 320a. When the sensor accommodation part <NUM> is disposed between the two ice making cells 320a, the second temperature sensor <NUM> may be easily installed without increasing the volume of the first tray <NUM>. Also, when the sensor accommodation part <NUM> is disposed between the two ice making cells 320a, the temperatures of at least two ice making cells 320a may be affected. Thus, the temperature sensor may be disposed so that the temperature sensed by the second temperature sensor maximally approaches an actual temperature inside the cell 320a.

For example, the sensor accommodation part <NUM> may be disposed between two adjacent upper cells 320b (or first cells) among three upper cells 320b arranged side by side.

As a result, the second temperature sensor <NUM> may represent the temperatures of both the first tray <NUM> and the second tray <NUM> and minimize an exposure of the second temperature sensor <NUM> to the outside so that it is affected as little as possible from the external temperature.

The second temperature sensor <NUM> may be disposed between the first cell walls 321a (see <FIG>) of the two ice making cells 320a of the first tray <NUM> as illustrated in <FIG> so as to be in contact with the first tray <NUM> at the outside of the first cell walls 321a.

Also, the second temperature sensor <NUM> may measure a temperature of the cell that is frozen last among the plurality of ice making cells 320a, thereby preventing ice from being separated in a state in which the ice separation is not completed.

The cell that is frozen last among the plurality of ice making cells 320a may be an ice making cell 320a that is disposed farthest from the cold air supply part <NUM> in a direction in which the cold air is supplied.

Also, the second temperature sensor <NUM> may be disposed so that a distance between the cold air hole <NUM> and the second temperature sensor <NUM> is less than a distance between the ice making cell, which is farthest from the cold air hole <NUM> for supplying the cold air by the cold air supply part <NUM>, and the cold air hole <NUM> among the plurality of ice making cells 320a.

In <FIG> and <FIG>, the sensor accommodation part <NUM> may be disposed between the right ice making cell (or the first ice making cell) and the central ice making cell (or the second ice making cell) of both right and left sides of the three ice making cells to accommodate at least a portion of the second temperature sensor <NUM>.

Also, when the sensor accommodation part <NUM> is disposed between the upper cell and the central upper cell of both the left and right sides in the three upper cells 320b, a distance between the right upper cell and the central upper cell is greater than a distance between the left upper cell and the central upper cell. This is done for providing a seat on which the second temperature sensor <NUM> is accommodated.

The second temperature sensor <NUM> may be disposed adjacent to the second tray <NUM> and may also be disposed between the plurality of lower cells 320c.

The wire <NUM> connected to the second temperature sensor <NUM> may be guided to an upper side of the first tray case <NUM>. Thus, in order to prevent an interference due to the electric wire <NUM> and to prevent the electric wire <NUM> from being broken due to deformation, the second temperature sensor <NUM> may be mounted on the tray that does not rotate by the driver <NUM> among the first tray <NUM> and the second tray <NUM>. That is, the second temperature sensor <NUM> may be mounted on the first tray <NUM> that is fixed without rotating by the driver <NUM>.

When the second temperature sensor <NUM> is mounted adjacent to the transparent ice heater <NUM>, there is a possibility that accuracy at a time point at which the ice making is completed is deteriorated due to the heat supplied from the transparent ice heater <NUM>.

Also, the transparent ice heater <NUM> causes lower water to be frozen later than upper water, and thus, a temperature change may hardly occur during the ice making process, and the phase change temperature may be maintained. Thus, if the second temperature sensor <NUM> is mounted adjacent to the tray that is in contact with the transparent ice heater <NUM>, the temperature change of the temperature sensor during the ice making process is not large, and thus, it may be difficult to adjust a heating amount of the transparent ice heater <NUM> in stages.

Thus, the second temperature sensor <NUM> may be mounted on the tray that is disposed farther from the transparent ice heater <NUM> so as to be less affected by the transparent ice heater <NUM>.

A portion of the ice separation heater <NUM> may be disposed higher than the second temperature sensor <NUM> and is spaced apart from the second temperature sensor <NUM>.

Also, the second temperature sensor <NUM> may be provided in the first heater case <NUM> together with the ice separation heater <NUM>. Here, the reliability of the second temperature sensor <NUM> is secured because the second temperature sensor <NUM> and the ice separation heater <NUM> are spaced apart from each other.

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

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

The second cell wall <NUM> may include a top surface 381a. The top surface 381a of the second cell wall <NUM> may be referred to as a top surface 381a of the second tray <NUM>. The top surface 381a of the second cell wall <NUM> may be disposed lower than an upper end of the circumferential wall <NUM>.

The first tray <NUM> may include a first cell wall 321a defining a 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 have an arc shape having a radius of curvature at the center of the shaft <NUM>. 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 bottom surface 321d. The bottom surface 321b of the first cell wall 321a may be referred to herein as a bottom surface 321b of the first tray <NUM>. The bottom surface 321d of the first cell wall 321a may be in contact with the top surface 381a of the second cell wall 381a.

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

<FIG> illustrates that the entirety of the bottom surface 321d of the first cell wall 321a and the top surface 381a of the second cell wall <NUM> are spaced apart from each other. Accordingly, the top surface 381a of the second cell wall <NUM> may be inclined to form a predetermined angle with respect to the bottom surface 321d of the first cell wall 321a.

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

In the state of <FIG>, the circumferential wall <NUM> may surround the first cell wall 321a. Also, an upper end of the circumferential wall <NUM> may be positioned higher than the bottom surface 321d of the first cell wall 321a.

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

The angle formed between the top surface 381a of the second tray <NUM> and the bottom surface 321d of the first tray <NUM> at the ice making position is less than that between the top surface 382a of the second tray and the bottom surface 321d of the first tray at the water supply position.

At the ice making position, the top surface 381a of the second cell wall <NUM> may contact all of the bottom surface 321d of the first cell wall 321a.

At the ice making position, the top surface 381a of the second cell wall <NUM> and the bottom surface 321d of the first cell wall 321a may be disposed to be substantially parallel to each other.

In this embodiment, the water supply position of the second tray <NUM> and the ice making position are different from each other. This is done for uniformly distributing the water to the plurality of ice making cells 320a without providing a water passage for the first tray <NUM> and/or the second tray <NUM> when the ice maker <NUM> includes 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 provided in the first tray <NUM> and/or the second tray <NUM>, the water supplied into the ice maker <NUM> may be distributed to the plurality of ice making cells 320a along the water passage.

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

In this case, there is a possibility that the ice sticks to each other even after the completion of the ice, and even if the ice is separated from each other, some of the plurality of ice includes ice made in a portion of the water passage. Thus, the ice may have a shape different from that of the ice making cell.

However, like this embodiment, when the second tray <NUM> is spaced apart from the first tray <NUM> at the water supply position, water dropping to the second tray <NUM> may be uniformly distributed to the plurality of second cells 320c of the second tray <NUM>.

For example, the first tray <NUM> may include a communication hole 321e. 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 of the plurality of communication holes 321e. In this case, the water supplied through the one communication hole 321e drops to the second tray <NUM> after passing through the first tray <NUM>.

In the water supply process, water may drop into any one of the second cells 320c of the plurality of second cells 320c of the second tray <NUM>. The water supplied to one of the second cells 320c may overflow from the one of the second cells 320c.

In this embodiment, since the top surface 381a of the second tray <NUM> is spaced apart from the bottom surface 321d of the first tray <NUM>, the water overflowed from any one of the second cells 320c may move to the adjacent other second ell 320c along the top surface 381a of the second tray <NUM>. Therefore, the plurality of second cells 320c of the second tray <NUM> may be filled with water.

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

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

When the second tray <NUM> move 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.

When water passages are provided in the first tray <NUM> and/or the second tray <NUM>, ice made in the ice making cell 320a may also be made in a portion of the water passage.

In this case, when the controller of the refrigerator controls one or more of the cooling power of the cold air supply part <NUM> and the heating amount of the transparent ice heater to vary according to the mass per unit height of the water in the ice making cell 320a, one or more of the cooling power of the cold air supply part <NUM> and the heating amount of the transparent ice heater may be abruptly changed several times or more in the portion at which the water passage is provided.

This is because the mass per unit height of the water increases more than several times in the portion at which the water passage is provided. In this case, reliability problems of components may occur, and expensive components having large maximum output and minimum output ranges may be used, which may be disadvantageous in terms of power consumption and component costs. As a result, the present invention may require the technique related to the aforementioned ice making position to make the transparent ice.

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

Referring to <FIG>, the refrigerator according to this embodiment may include an 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.

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

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

The controller <NUM> 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>.

When the door opening/closing detection part <NUM> detects the opening/closing of the door (a state in which the door is opened and closed), the controller <NUM> may determine whether cooling power of the cold air supply part <NUM> is variable.

When the door opening/closing detection part <NUM> detects the opening/closing of the door, the controller <NUM> determines whether an output of the transparent ice heater <NUM> is variable based on a temperature detected by the second temperature sensor <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 a temperature sensor in the refrigerator) that detects a temperature of the freezing compartment <NUM>.

The controller <NUM> may control the cold air supply part <NUM> based on the temperature detected by the first temperature sensor <NUM>.

The controller <NUM> may determine whether the ice making is completed based on the temperature detected 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 illustrating a state in which supply of water is completed at the water supply position, <FIG> is a view illustrating a state in which ice is generated at the ice making position. <FIG> is a view illustrating a state in which the second tray and the first tray are separated from each other in the ice separation process, and <FIG> is a view illustrating a state in which the second tray moves to the ice separation position in the 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>.

In the state in which the second tray <NUM> moves to the water supply position, the water supply starts (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> move in the reverse direction, the top surface 381a of the second tray <NUM> comes close to the bottom surface 321e of the first tray <NUM>. Then, water between the top surface 381a of the second tray <NUM> and the bottom surface 321e of the first tray <NUM> is divided into each of the plurality of second cells 320c and then is distributed. When the top surface 381a of the second tray <NUM> and the bottom surface 321e of the first tray <NUM> contact each other, water is filled in the first cell 320b.

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 (S5).

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.

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.

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 detected 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 exists in the ice making cell 320a, after the ice starts to be made in the ice making cell 320a, the temperature detected 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 be 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 controller <NUM> may control the cooling power and/or the heating amount so that the cooling power of the cold air supply part <NUM> and/or 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.

In this specification, 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 the turn-off time of the transparent ice heater <NUM> in one cycle, or a ratio 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>.

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.

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 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 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.

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 increase step by step.

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 reduced again step by step 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 detected by the second temperature sensor <NUM> (S6). When it is determined that the ice making is completed, the controller <NUM> may turn off the transparent ice heater <NUM> (S7).

For example, when the temperature detected 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 detected 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 at least one or more of the ice maker heater <NUM> and the transparent ice heater <NUM> (S8).

When the ice separation heater <NUM> is turned on, heat of the ice separation heater <NUM> may be transferred to the first tray <NUM>, and thus, the ice may be separated from a surface (an inner surface) of the first tray <NUM>.

Also, the heat of the ice separation heater <NUM> is transferred to a contact surface between the first tray <NUM> and the second tray <NUM>, and thus, the bottom surface 321d of the first tray and the top surface 381a of the second tray <NUM> may be in a state capable of being separated from each other.

After at least one or more of the ice separation heater <NUM> and the transparent ice heater <NUM> are turned on, when the moving condition of the second tray <NUM> is satisfied, the controller <NUM> may turn off the heater that is turned on and may rotate the second tray <NUM> in the forward direction so that the second tray <NUM> moves to the ice separation position (S9).

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, the ice may be separated from the surface of the first tray <NUM> by the heat of the ice separation heater <NUM>.

In this case, the ice may move together with the second tray <NUM> while the ice is supported by the second tray <NUM>.

In the operation of the ice separation heater <NUM>, ice may not be separated from the surface of the first tray <NUM> even by the operation of the ice separation heater <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>.

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 second 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 tray <NUM> is pressed by the second pusher <NUM> as illustrated in <FIG>, the ice may be separated from the second tray <NUM> to fall downward.

Particularly, 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> and the extension part <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 (S10). 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.

In this embodiment, the cooling power of the cold air supply part <NUM> may be determined corresponding to a target temperature of the freezing compartment <NUM>. The cold air generated by the cold air supply part <NUM> may be supplied to the freezing chamber <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 chamber <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>.

A heating amount (or output) of the transparent ice heater <NUM> determined in consideration of the predetermined cooling power of the cold air supply part <NUM> is referred to as a reference heating amount (or reference output). The 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, a case in which the heat transfer amount of cold air and water is reduced may be, for example, a case in which the cooling power of the cold air supply pat <NUM> is reduced, a case in which the door is opened, and air having a temperature higher than the temperature of the cold air in the freezing compartment <NUM> is supplied to the freezing compartment <NUM>, a case in which food having a temperature higher than the temperature of cold air in the freezing compartment <NUM> is put into the freezing compartment <NUM>, or a case a defrost heater (not shown) for defrosting of the evaporator is turned on.

For example, 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 rapid 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.

On the other hand, the target temperature of the freezer compartment <NUM> increases, the operation mode of the freezing compartment <NUM> is changed from the rapid cooling mode to the normal mode, the output of at least one of the compressor 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 heat transfer amount of cold air and water increases, the temperature of the cold air around the ice maker <NUM> decreases to increase in rate of ice generation.

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.

Claim 1:
A refrigerator comprising:
a storage chamber configured to store food;
a first tray (<NUM>) configured to define one portion of an ice making cell (320a) that is a space in which water is phase-changed into ice by cold air;
a second tray (<NUM>) configured to define the other portion of the ice making cell (320a);
a heater (<NUM>, <NUM>) disposed adjacent to at least one of the first tray (<NUM>) or the second tray (<NUM>), wherein the heater (<NUM>, <NUM>) comprises an ice separation heater (<NUM>) configured to supply heat to the at least one of the first tray (<NUM>) or the second tray (<NUM>) in an ice separation process;
a controller (<NUM>) configured to control the heater (<NUM>, <NUM>),
wherein the controller (<NUM>) controls:
the second tray (<NUM>) to move to an ice making position after water supply to the ice making cell (320a) is completed so that a cold air supply part (<NUM>) supplies the cold air to the ice making cell (320a);
the second tray (<NUM>) to move to an ice separation position in a forward direction so as to take the ice out of the ice making cell (320a) after generation of the ice in the ice making cell (320a) is completed; and
the second tray (<NUM>) to move from the ice separation position to a water supply position in a reverse direction after a separation of the ice is completed,
characterized in that the refrigerator comprises:
a temperature sensor (<NUM>) configured to detect a temperature of the water or of the ice of the ice making cell (320a), wherein the temperature sensor (<NUM>) is in contact with the at least one of the first tray (<NUM>) or the second tray (<NUM>) and wherein the temperature sensor (<NUM>) is disposed to be spaced apart from the ice separation heater (<NUM>);
wherein a distance from the temperature sensor (<NUM>) to a contact surface between the first tray (<NUM>) and the second tray (<NUM>) is less than a distance from the ice separation heater (<NUM>) to the contact surface between the first tray (<NUM>) and the second tray (<NUM>); and
wherein the heater (<NUM>, <NUM>) also comprises a transparent ice heater (<NUM>) that is turned on in at least partial section while the cold air supply part (<NUM>) supplies the cold air so that bubbles dissolved in the water within the ice making cell (320a) move from a portion, at which the ice is generated, toward the water that is in a liquid state to generate transparent ice.