Patent Description:
A refrigerator is an apparatus used to freshly store food for a long time. The refrigerator has a food storage compartment therein, wherein the food storage compartment is always maintained at a low temperature state by a cooling cycle to allow food to be maintained at a fresh state.

The food storage compartment provides a plurality of storage compartments having their respective properties different from each other to allow a user to select a storage method suitable for each food by considering types and features of food and a storage period of food. Main examples of the storage compartments include a refrigerating compartment and a freezing compartment.

If a user desires to drink beverage or water together with ices, the user should take ices out of an ice tray provided in the freezing compartment by opening a freezing compartment door. However, in this case, there is inconvenience in that the user should separate ices from the ice tray after opening the freezing compartment door and then taking the ice tray out of the freezing compartment. Also, if the user opens the freezing compartment door, the cool air of the freezing compartment is taken out, whereby a temperature of the freezing compartment is increased. Therefore, since a compressor should be driven for a longer time, a problem occurs in that energy is wasted.

In this respect, an automatic ice maker has been developed, which is provided inside a refrigerator but may discharge ices separated from the ice tray through a dispenser if necessary after automatically supplying water thereto and then making the ices. However, the ice maker of the related art needs much energy consumption, whereby improvement will be required in view of various aspects.

<CIT>, <CIT>, <CIT> and <CIT> discloses ice makers used in refrigerators.

Accordingly, the present invention is directed to an ice maker which substantially obviate one or more problems due to limitations and disadvantages of the related art.

An object of the present invention is to provide an ice maker in which ice separation is easily made to reduce energy consumption while ice separation is being made.

Another object of the present invention is to provide an ice maker in which the cool air is easily transferred to ices during ice making to increase an ice making amount and thus improve energy efficiency.

The present invention provides an ice maker comprising an ice tray for receiving water to form ice; a motor capable of performing forward and backward rotation; an ejector rotating ice formed by the ice tray to discharge the ice from the ice tray, the ejector including a rotary shaft rotated by being axially connected to the motor and a protrusion pin protruded in a radius direction of the rotary shaft; a heater for selectively supplying heat to the ice tray; and a first sensor unit for sensing a rotation angle of the protrusion pin, wherein the first sensor unit senses a preset rotation angle of the protrusion pin before the ice formed by the ice tray is completely discharged from the ice tray, and the heater is controlled to be turned off at the preset rotation angle sensed by the first sensor unit, and wherein the first sensor unit is controlled to sense a second preset rotation angle of the protrusion pin and the heater is controlled to be turned on at the second preset rotation angle sensed by the first sensor unit.

The ice maker of the present invention further comprises a discharge guide for guiding the ice to be dropped onto an ice bank arranged below the ice maker, and the first sensor unit may sense whether the protrusion pin has reached the preset rotatation angle before the ice ascends to the discharge guide.

The first sensor unit may sense whether the protrusion pin has reached an angle which allows the ice formed by the ice tray to rotate at <NUM>° or less from from an initial position of the ice along an inner surface of the ice tray.

The first sensor unit may sense whether the protrusion pin has reached an angle before the protrusion pin is arranged to be vertical to the ground after being in contact with the ice formed by the ice tray.

The first sensor unit may sense whether the protrusion pin has reached an angle which allows the ice formed by the ice tray to be rotated at a certain angle from an initial position of the ice along an inner surface of the ice tray.

The first sensor unit may sense whether the protrusion pin has moved the ice formed by the ice tray at a predetermined angle from an initial position after the heater has been driven.

The first sensor unit may sense a first position, a second position and a third position of the protrusion pin, wherein the angles of the protrusion pin corresponding to the first position, the second position and the third position are different from one another. If the protrusion pin reaches the third position, the heater may be turned off.

The first position may be the initial position where ice separation starts, the second position may be the position where a state that the ice bank arranged below the ice maker is ful of ice is sensed, and the third position may be the position where the ice formed by the ice tray moves at a predetermined distance along an inner surface of the ice tray.

If the first sensor unit senses that the protrusion pin has reached the first position, the heater may be turned on.

The ice maker of the present invention further comprises a first cam portion axially coupled to the rotary shaft of the ejector and provided with three grooves formed on an outer circumference, and a first rotation member rotated along the outer circumference in contact with the outer circumference of the first cam portion, wherein the first sensor unit may sense whether first rotation member is engaged in the groove of the first cam portion.

A magnet is provided at one end of the first rotation member, and the first sensor unit may include a first hall sensor for sensing a voltage change according to movement of the magnet.

A rotation direction of the first cam portion when the first sensor unit senses the second position may be opposite to a rotation direction of the first cam portion when the first sensor unit senses the first position and the third portion.

The ice maker of the present invention may further comprise a full-ice sensing bar for sensing whether the ice in the ice bank arranged below the ice maker has exceeded a set height, wherein said sensing is performed by the motor rotating the full-ice sensing bar.

The ice maker of the present invention may further comprise a second sensor unit for sensing rotation of the full-ice sensing bar.

The ice maker of the present invention may further comprise a full-ice sensing bar rotation gear engaged with the full-ice sensing bar to rotate the full-ice sensing bar, and a magnet provided in the full-ice sensing bar rotation gear, wherein the second sensor unit may include a second hall sensor for sensing a voltage change according to movement of the magnet.

The accompanying drawings, which are included to provide a further understanding of the invention, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:.

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

<FIG> is a perspective view illustrating that an ice maker according to the present invention is provided in a refrigerator door.

The ice maker may be applied to a bottom freezer type refrigerator in which a freezing compartment is arranged below a refrigerating compartment or a top mounting type refrigerator in which a freezing compartment is arranged on a refrigerating compartment. Also, the ice maker may be applied to a side by side type refrigerator in which a refrigerating compartment and a freezing compartment are arranged at both sides.

A refrigerator comprises a freezing compartment <NUM> and a refrigerating compartment <NUM>, in which contents are stored in a cabinet <NUM> constituting an external appearance. A freezing compartment door <NUM> and a refrigerating compartment door <NUM>, which are intended to open or close the freezing compartment <NUM> and the refrigerating compartment, are respectively provided on front surfaces of the freezing compartment <NUM> and the refrigerating compartment <NUM>. A bottom freezing type refrigerator, in which the freezing compartment <NUM> is arranged below the cabinet <NUM>, is introduced, but this example is not limited to this bottom freezing type refrigerator.

The refrigerating compartment <NUM> is opened or closed at both sides in such a manner that two refrigerating compartment doors <NUM> are hinge-coupled with a side of a refrigerator main body, and the freezing compartment door <NUM> is opened or closed in a forward or backward direction of the refrigerator body in a sliding manner.

The freezing compartment door <NUM> and the refrigerating compartment door <NUM> may be arranged differently depending positions of the freezing compartment <NUM> and the refrigerating compartment <NUM>. For example, the refrigerator may be applied to a top mount type refrigerator, a two-door type refrigerator, etc. regardless of types.

An ice making compartment <NUM> may be provided in any one of the refrigerating compartment doors <NUM>. A sealed space surrounded by a frame is provided at a rear side of the refrigerating compartment door <NUM>, and may form the ice making compartment <NUM>. Since the ice making compartment <NUM> is adjacent to the refrigerating compartment <NUM>, it is preferable that the ice making compartment <NUM> is heat-insulated so as not to generate heat-exchange with the refrigerating compartment <NUM>.

The ice making compartment <NUM> may be provided inside the freezing compartment <NUM> or the refrigerating compartment <NUM>. However, considering a user's access convenience and efficiency in use of an inner space of the cabinet <NUM>, it is preferable that the ice making compartment <NUM> is provided in the refrigerating compartment door <NUM>.

The ice maker <NUM> may be provided inside the ice making compartment <NUM>, and an ice bank <NUM> and a dispenser <NUM> are provided below the ice making compartment <NUM>, wherein ices are temporarily stored in the ice bank <NUM> and the dispenser <NUM> is to discharge ices in accordance with a user's request.

A perspective view illustrating an external appearance of the ice maker <NUM> is shown in <FIG>, and an exploded view illustrating the ice maker <NUM> is shown in <FIG>.

The ice maker <NUM> includes an ice tray <NUM> to which water supplied to make ices, an ejector <NUM> rotated to take out ices made in the ice tray, a heater <NUM> provided to be in contact with the ice tray, selectively heating the ice tray to easily separate the ices from the ice tray, a case <NUM> mounted at one side of the ice tray, and a brushless direct current motor (BLDC) <NUM> mounted inside the case <NUM>, selectively rotating the ejector <NUM> to enable forward rotation and backward rotation.

The ice tray <NUM> is a structure where ices are formed by water supply, and has a semi-cylindrical shape with an opened upper portion to store water and ices therein as shown in <FIG>.

A plurality of partition ribs <NUM> for partitioning the inner space of the ice tray <NUM> into a plurality of ice making spaces are provided inside the ice tray <NUM>. The plurality of partition ribs <NUM> are formed to be extended upwardly inside the ice tray <NUM>. The plurality of partition ribs <NUM> may allow a plurality of ices to be simultaneously made in the ice tray.

A water supply unit <NUM> is provided at a right upper portion of the ice tray <NUM> to allow water to be supplied from an externally connected water supply hose (not shown) to the ice tray <NUM>.

The water supply unit <NUM> has an opened upper portion, and is preferably provided with a water supply unit cover <NUM> for preventing water from splashing during water supply.

Meanwhile, the ice tray <NUM> includes an anti-overflow wall <NUM> for preventing water from overflowing, formed to be extended from a rear upper surface to an upward direction. If the ice maker <NUM> is provided in the refrigerating compartment door <NUM>, water supplied to the ice tray <NUM> may overflow in accordance with movement of a door which is generally rotated to be opened or closed. Therefore, the anti-overflow wall <NUM> forms a high wall at a rear side of the ice tray <NUM> to prevent water inside the ice tray <NUM> from overflowing toward the rear of the ice tray <NUM>.

The ejector <NUM> includes a rotary shaft <NUM> and a plurality of protrusion pins <NUM>. The rotary shaft <NUM> is arranged at an upper side inside the ice tray <NUM> to cross the center in a length direction as shown in <FIG>. The inner surface of the ice tray <NUM> has a semi-cylindrical shape having the center of the rotary shaft <NUM> as the center. The plurality of protrusion pins <NUM> are extended to an outer circumference of the rotary shaft <NUM> in a radius direction. It is preferable that the plurality of protrusion pins <NUM> are formed at the same interval along the length direction of the rotary shaft <NUM>. Particularly, the plurality of protrusion pins <NUM> are arranged one by one per space partitioned in the ice tray <NUM> by the partition ribs <NUM>.

The heater <NUM> is arranged below the ice tray <NUM>. The heater <NUM> is a heat transfer heater, and is preferably formed in a U shape. The heater <NUM> heats the surface of the ice tray <NUM> to slightly melt ice on the surface of the ice tray <NUM>. Therefore, when the ejector <NUM> separates ices while being rotated, ices on the surface of the ice tray <NUM> may easily be separated from the surface of the ice tray <NUM>.

Meanwhile, a plurality of discharge guides <NUM> for guiding ices separated by the ejector <NUM> to be dropped on the ice bank <NUM> arranged below the ice maker <NUM> are provided above the front of the ice tray <NUM>. The plurality of discharge guides <NUM> are fixed to corner portions at the front of the ice tray <NUM> and extended to be close to the rotary shaft <NUM>. A predetermined gap exists between the plurality of discharge guides <NUM>. When the rotary shaft <NUM> is rotated, the protrusion pins <NUM> pass through the gap. It is preferable that the discharge guide <NUM> has an upper surface inclined to be higher toward its end, that is, the rotary shaft <NUM> to allow ices to be slid to the front by means of self-load.

Preferably, the ice tray <NUM> further includes an anti-overflow member <NUM> for preventing water from overflowing toward the front of the ice tray, provided below the discharge guide <NUM>. Preferably, the anti-overflow member <NUM> is made in a plate shape to prevent water from overflowing, and is made of a flexible plastic material.

Also, when the ejector <NUM> is rotated, the anti-overflow member <NUM> are formed provided with "T" shaped slits <NUM> per position corresponding to the protrusion pins <NUM> such that the protrusion pins <NUM> may pass through the anti-overflow member <NUM>. Since the anti-overflow member <NUM> is made of a flexible material, when the protrusion pins <NUM> pass through the slit <NUM>, the slit <NUM> may generate a gap while being deformed, and then may be restored after the protrusion pins <NUM> pass therethrough.

A driving device <NUM> for selectively rotating the ejector <NUM> is provided at an opposite side of the water supply unit <NUM> in the ice tray <NUM>.

The driving device <NUM> is provided inside the case <NUM> to protect inner parts, and includes a motor <NUM> (see <FIG>) inside the case <NUM> as described later. The driving device <NUM> selectively supplies a power source to the motor <NUM> and the heater <NUM>.

Also, the motor <NUM> selectively rotates a full-ice sensing bar for sensing whether the ice bank <NUM> arranged below the ice maker <NUM> is fully filled with ices.

Meanwhile, a switch <NUM> for experimentally operating the ice maker <NUM> is provided at the front of the driving device <NUM>. If the switch <NUM> is pushed for several seconds or more, the ice maker <NUM> is operated in a test mode to identify whether there is a problem in the ice maker <NUM>.

The ice maker <NUM> is provided with an air guide <NUM> arranged to surround the front below the ice tray <NUM>. The air guide <NUM> is provide to surround the front of the ice tray <NUM>, a cool air moving path is formed between the air guide <NUM> and the front surface of the ice tray <NUM>, and a plurality of cool air discharge holes <NUM> are preferably arranged at the center of the front portion <NUM> from side to side. The cool air guided to the lower portion of the ice tray <NUM> may be discharged to the front surface of the ice maker <NUM> through the cool air discharge holes <NUM>.

Also, it is preferable that a plurality of fins <NUM> are formed on the entire surface of the ice tray <NUM> spaced apart from the front portion <NUM>. The fins <NUM> may expedite heat transfer to the ice tray <NUM> when the cool air is discharged through the cool air discharge holes <NUM>, whereby water may quickly be cooled to quickly generate ices.

The front portion <NUM> of the air guide <NUM> may be formed in a single body with the discharge guide <NUM>. In this case, the discharge guide <NUM> and the anti-overflow member <NUM> may be fixed to each other using a plurality of screws at the front on the ice tray <NUM>, whereby the front portion <NUM> may be fixed to the front surface of the ice tray <NUM> to be spaced apart from the ice tray <NUM> at a predetermined interval.

Next, a structure of the driving device will be described with reference to <FIG>.

The driving device <NUM> includes a case <NUM> mounted at one side of the ice tray, and a motor <NUM> mounted inside the case, selectively rotating the ejector.

The case <NUM> has a cuboid shape, is provided with mounting portions such as various gears and cams therein, and has an opened side to which a cover is coupled.

The motor <NUM> rotates the rotary shaft <NUM> of the ejector <NUM> at a predetermined angle in a forward or backward direction. To this end, the motor <NUM> is preferably a motor that enables forward or backward rotation. Particularly, the motor <NUM> is preferably a brushless direct current motor (BLDC).

If the motor <NUM> is rotated in a forward or backward direction, a complicated connection structure of a gear and cam for rotating the ejector <NUM> in a forward or backward direction is not required, and it is easy to rotate the full-ice sensing bar <NUM>, in a forward or backward direction, which should be rotated at a predetermined angle in a forward or backward direction.

Also, if the brushless direct current motor is used, since a volume of the motor is smaller than the case that the direct current motor is used, the driving device may have a small volume, whereby the ice tray <NUM> may be made more greatly in a limited space.

The motor <NUM> is deaccelerated through a plurality of reduction gears <NUM>, <NUM>, <NUM> and <NUM> and then axially coupled to the rotary shaft <NUM> of the ejector <NUM> to rotate an ejector rotation gear <NUM> for rotating the ejector. At this time, since the motor <NUM> may be rotated in a forward or backward direction, if the motor is rotated in a first direction, the ejector is rotated in the first direction, and if the motor is rotated in a second direction, the ejector is rotated in the second direction.

Also, the plurality of four reduction gears <NUM>, <NUM>, <NUM> and <NUM> are shown, a reduction ratio and the number of the plurality of reduction gears may be controlled properly in accordance with specification of the motor <NUM>.

Preferably, the motor <NUM> is connected to a circuit board <NUM> provided at one side inside the case <NUM> and thus supplied with a power source.

It is preferable that the driving device <NUM> further includes a first sensor unit for sensing a position of a rotation angle of the ejector, and a second sensor unit for sensing a rotation angle position of the full-ice sensing bar. Each of the first sensor unit and the second sensor unit may include a hall sensor to sense related information.

A first cam portion <NUM> provided with two grooves made of a disk type and formed at a predetermined angle position on the outer circumference is provided at one side of the ejector rotation gear <NUM>. The two grooves include a first groove <NUM> for defining an initial rotation angle position of the ejector <NUM> and a second groove <NUM> formed to be spaced apart from the first groove <NUM> at a predetermined angle. The first groove <NUM> is formed at the same depth as that of the second groove <NUM>, and is preferably formed at an angle greater than that of the second groove <NUM>.

A first rotation member <NUM> interworking with the first cam portion <NUM> in contact with the first cam portion <NUM> is provided at one side of the ejector rotation gear <NUM>. The first rotation member <NUM> is provided with a first protrusion <NUM> at one side, and the first protrusion <NUM> is rotated while sliding along the outer circumference and two grooves of the first cam portion <NUM>.

A magnet <NUM> is provided at an end of the first rotation member <NUM>, and a first hall sensor <NUM> for measuring a voltage signal generated as the magnet <NUM> approaches to a position close to the magnet <NUM> is provided.

The first hall sensor <NUM> is a sensor based on a hall effect of a voltage generated when the magnet <NUM> approaches thereto. Since the first hall sensor <NUM> is a sensor to which a current flows, it is preferable that the first hall sensor <NUM> is installed in the circuit board <NUM>.

Since the first rotation member <NUM> is pulled to be always in contact with the first cam portion <NUM>, a first elastic member <NUM> is provided between one side of the first rotation member <NUM> and a lower fixed position in the case <NUM> to be in contact with the first cam portion <NUM> by downwardly pulling the first rotation member <NUM>.

As shown in <FIG>, the first elastic member <NUM> may be installed to be hung between a protrusion downwardly protruded from a middle portion of the first rotation member <NUM> and a ring protruded from a position where a temperature sensor <NUM>, which will be described later, is fixed.

The first sensor unit, which includes the first rotation member <NUM> and the first hall sensor <NUM>, may sense a rotation angle of the ejector <NUM> by sensing a position signal, which corresponds to a case that the first protrusion <NUM> is inserted into the first groove <NUM> and the second groove <NUM> of the first cam portion <NUM>, when the ejector rotation gear <NUM> is rotated.

Meanwhile, a temperature sensor unit <NUM> is provided inside the case <NUM> of the driving device <NUM> to adjoin a side of the ice tray <NUM> coupled to the side of the case <NUM>. The temperature sensor unit <NUM> includes a temperature sensor <NUM> for measuring a voltage signal according to a temperature of the ice tray <NUM>, and a conducting plate <NUM> of a metal material interposed to prevent water permeation with the ice tray <NUM>.

The temperature sensor <NUM> may be buried in a rubber of a waterproof and elastic material, and may be fixed to one side of the case <NUM>. Since the temperature sensor <NUM> is to measure a temperature of the ice tray <NUM>, an opening portion, through which the temperature sensor <NUM> may be exposed, is formed at one side of the case <NUM> made of a plastic material.

The temperature sensor <NUM> is not directly in contact with the ice tray <NUM> but in contact with the ice tray <NUM> through the conducting plate <NUM>. Therefore, the conducting plate <NUM> may prevent water permeation by blocking the opening portion formed at one side of the case <NUM> and at the same time measure a temperature of the ice tray <NUM> to be conducted to the temperature sensor <NUM>. The conducting plate <NUM> may be made of a metal material having high heat conductivity, and may be fixed to one side of the case <NUM> by insert molding after a plate of a stainless material is formed.

Also, since the temperature sensor <NUM> measures a voltage change according to a temperature change, the temperature sensor <NUM> is connected with the circuit board <NUM> by a wire.

Next, a side view illustrating that the inside of the driving device is viewed from a left side is shown in <FIG>.

A disk type second cam portion <NUM> having a diameter corresponding to a half of a diameter of the ejector rotation gear <NUM> is provided at a left side of the ejector rotation gear <NUM>. A groove <NUM> is formed at one side of the second cam portion <NUM>.

A second rotation member <NUM> rotated by interworking with the second cam portion <NUM> is provided near the second cam portion <NUM>. The second rotation member <NUM> is rotated at the front of the second cam portion <NUM>, and is entirely provided to surround the center of the ejector rotation gear <NUM>. A second protrusion <NUM> is formed on a surface at one end of the second rotation member <NUM>, that is, a surface toward the second cam portion <NUM> to be vertical to the surface, whereby a side of the second protrusion <NUM> is in contact with an outer circumference of the second cam portion <NUM>.

The other end of the ejector rotation gear <NUM> receives an elastic force to be upwardly rotated by the second elastic member <NUM>. The second elastic member <NUM> has both ends longitudinally spread in a spring type, and provides an elastic force spread in a radius direction unlike the first elastic member <NUM> that provides an elastic force pulled in a length direction. One side of the second elastic member <NUM> is installed to be hung in a ring portion protruded at the other end of the ejector rotation gear <NUM>, and other side of the second elastic member <NUM> is installed to be hung on one surface of the case.

A protrusion <NUM> is formed at one side of the front of the second cam portion <NUM> in the rotary shaft of the ejector rotation gear <NUM> in a radius direction. The protrusion <NUM> is mounted to be rotated at a predetermined angle range with respect to the rotary shaft of the ejector rotation gear <NUM>. The protrusion <NUM> is rotated at a predetermined angle in the same direction as that of the ejector rotation gear <NUM> when the ejector rotation gear <NUM> is rotated counterclockwise, whereby the second protrusion <NUM> of the second rotation member <NUM> may be inserted into the groove <NUM> of the second cam portion <NUM>. On the other hand, the protrusion <NUM> is rotated at a predetermined angle in the same direction as that of the ejector rotation gear <NUM> when the ejector rotation gear <NUM> is rotated clockwise, and is hung in a side of one end of the second protrusion <NUM> of the second rotation member <NUM>, whereby the second protrusion <NUM> cannot be inserted into the groove <NUM> of the second cam portion <NUM> and thus the second rotation member <NUM> cannot be rotated.

In other words, the protrusion <NUM> may upwardly rotate the second rotation member <NUM> only when the ejector rotation gear <NUM> is rotated counterclockwise.

An arc shaped large gear portion <NUM> is formed at the other end of the ejector rotation gear <NUM> and thus coupled with a rotation force transfer gear <NUM>. Since the arc shaped large gear portion <NUM> is rotated in the range of a predetermined angle, the large gear portion <NUM> is formed in an arc shape.

The rotation force transfer gear <NUM> includes an arc shaped small gear portion <NUM> rotated to be engaged with the arc shaped large gear portion <NUM>, and an arc shaped large gear portion <NUM> engaged with the ejector rotation gear <NUM>, rotating the ejector rotation gear <NUM>.

Since a rotation angle of the rotation force transfer gear <NUM> becomes greater than the arc shaped large gear portion <NUM> but does not exceed <NUM>°, the small gear portion <NUM> and the large gear portion <NUM> may be formed in an arc shape. The arc shaped large gear portion <NUM> rotates a full-ice sensing bar rotation gear <NUM> to which one end of the full-ice sensing bar <NUM> is axially coupled.

A third elastic member <NUM> is provided between the arc shaped small gear portion <NUM> and the arc shaped large gear portion <NUM>, wherein the arc shaped large gear portion <NUM> is rotatably coupled to the third elastic member <NUM> relatively with respect to the arc shaped small gear portion. The third elastic member <NUM> is a spring fitted into the rotary shaft of the rotation force transfer gear <NUM>, and its one end is supported in the arc shaped large gear portion <NUM> and its other end is supported in the arc shaped small gear portion <NUM>, whereby an elastic force is provided in an opening direction. Therefore, when the full-ice sensing bar <NUM> is rotated and descends to sense whether the ice bank <NUM> has been fully filled with ices, even though the full-ice sensing bar <NUM> is not rotated any more due to the ices fully filled in the ice bank <NUM>, the third elastic member <NUM> may be rotated at a predetermined angle, whereby the gears coupled with each other are not damaged.

The magnet <NUM> is fixed to one side of the full-ice sensing bar rotation gear <NUM>, and a second hall sensor <NUM> may be installed at one side below the circuit board <NUM>. The second hall sensor <NUM> may be provided in a protruded shape in view of a relative position with the magnet <NUM>.

The magnet <NUM> is rotated together with the full-ice sensing bar rotation gear <NUM> as the full-ice sensing bar rotation gear <NUM> is rotated. The magnet <NUM> is the closest to the second hall sensor <NUM> in a position where the full-ice sensing bar <NUM> is rotated toward the lowest portion, whereby the second hall sensor <NUM> senses a signal at the time when the magnet <NUM> is the closest to the second hall sensor <NUM>. That is, if the second hall sensor <NUM> senses that the full-ice sensing bar <NUM> is upwardly rotated, descends and then is rotated toward the lowest position, the second hall sensor <NUM> may sense that the ice bank <NUM> cannot be fully filled with ices.

Meanwhile, the circuit board <NUM> is connected with a switch <NUM> provided inside the case <NUM> of the driving device <NUM> and partially protruded to the outside of the case <NUM>. Also, the circuit board <NUM> is connected with the motor <NUM> to adjoin the motor <NUM>, includes the first and second hall sensors <NUM> and <NUM> installed therein, and is connected with the temperature sensor <NUM> provided inside the case <NUM> by a wire.

The circuit board <NUM> performs a test mode in accordance with an action signal of the switch <NUM>, rotates the motor <NUM> in a forward direction or backward direction by operating the motor <NUM>, and transfers sensing signals of the first and second hall sensors <NUM> and <NUM> and the temperature sensor <NUM> to a main controller (not shown) provided in the refrigerator main body. Also, the circuit board <NUM> operates the motor <NUM> by receiving an operation command signal from the main controller.

Since the circuit board <NUM> does not include a controller for controlling the ice maker <NUM> unlike the related art, its size may be made with a very small size. Instead, the circuit board <NUM> may transfer a sensing signal and a command signal to the main controller, whereby the main controller may control the ice maker <NUM>.

Next, operations of the first rotation member and the second rotation member will be described with reference to <FIG> and <FIG>.

<FIG> illustrates some of inner elements of the driving device, wherein an operation state of the first hall sensor unit is viewed from a right side, that is, a side where the ejector exists.

First of all, <FIG> illustrates a state that the protrusion pins <NUM> of the ejector <NUM> are arranged in an initial position (this position is referred to as a "first position"). At this time, since the first protrusion <NUM> of the first rotation member <NUM> is inserted into the first groove <NUM> of the first cam portion <NUM>, the first rotation member <NUM> is pulled by the first elastic member <NUM> and downwardly rotated. Since the first hall sensor <NUM> is spaced apart from the magnet <NUM>, the first hall sensor <NUM> fails to sense a signal.

Next, <FIG> illustrates a state that the protrusion pins <NUM> of the ejector <NUM> are upwardly rotated by a reverse rotation of the motor at a predetermined angle for full-ice sensing (this position is referred to as a "second position"). At this time, since the first protrusion <NUM> of the first rotation member <NUM> is inserted into the second groove <NUM> of the first cam portion <NUM>, the first rotation member <NUM> is pulled by the first elastic member <NUM> and downwardly rotated. Even at this time, since the first hall sensor <NUM> is spaced apart from the magnet <NUM>, the first hall sensor <NUM> fails to sense a signal.

When the first protrusion <NUM> passes through the outer circumference between the first groove <NUM> and the second groove <NUM> of the first cam portion <NUM>, since the first protrusion <NUM> is pushed up by the outer circumference of the first cam portion <NUM>, the first rotation member <NUM> is upwardly rotated in spite of a pulling force of the first elastic member <NUM> as shown in <FIG>. At this time, since the first hall sensor <NUM> is spaced apart from the magnet <NUM>, the first hall sensor <NUM> senses a signal.

That is, the first hall sensor <NUM> continuously senses a signal when the first protrusion <NUM> passes through the outer circumference not the first and second grooves <NUM> and <NUM> of the first cam portion <NUM>, and stops from sensing a signal when the first protrusion <NUM> is inserted into the first and second grooves <NUM> and <NUM> of the first cam portion <NUM>, whereby the rotation angle position of the ejector <NUM> may be determined.

Meanwhile, if the ejector rotation gear <NUM> moves to the position of <FIG>, the full-ice sensing bar <NUM> is rotated to upwardly move in accordance with the operation of the second rotation member <NUM> as described later.

In case of the full-ice sensing operation, the ejector rotation gear <NUM> is rotated from the initial position of <FIG> to the position of <FIG> and then rotated to the position of <FIG> (rotated clockwise and then rotated counterclockwise). This means that the motor <NUM> rotates the ejector rotation gear <NUM> at a predetermined angle in a backward direction and then rotates the ejector rotation gear <NUM> in a forward direction. Therefore, as the full-ice sensing bar <NUM> is rotated from the downward position as shown in <FIG> to the upward position as shown in <FIG> and then descends toward the downward position, the second hall sensor <NUM> senses whether the full-ice sensing bar <NUM> descends as much as possible, as described later.

If the full-ice sensing bar <NUM> descends to the maximum downward position as shown in <FIG>, it may be determined that the ice bank <NUM> is not fully filled with ices, and if the full-ice sensing bar <NUM> fails to descend to the maximum downward position due to ices in the middle of descending toward the downward position, it may be determined that the ice bank <NUM> is fully filled with ices.

If it is determined that the ice bank <NUM> is not fully filled with ices, the heater <NUM> is first heated and then the ejector <NUM> is rotated at <NUM>° in a forward direction (counterclockwise direction). Then, the ices in the ice tray <NUM> are separated from the ice tray <NUM> and dropped onto the ice bank <NUM>. A middle state that the ejector <NUM> is rotated for ice separation is shown in <FIG>. At this state, since the magnet <NUM> is maintained to be close to the first hall sensor <NUM>, the state of <FIG> is maintained until the first rotation member <NUM> is rotated to descend, and the first hall sensor <NUM> continues to sense this state.

In this case, when the ejector <NUM> reaches the second position of <FIG> prior to returning to the initial position (the first position), the heated heater <NUM> is turned off. Since the heater <NUM> is an electric heating appliance and needs much power consumption, it is possible to reduce power consumption by reducing the heater operation time.

Next, <FIG> illustrates that the full-ice sensing bar <NUM> is rotated and the second hall sensor <NUM> senses the rotation of the full-ice sensing bar <NUM> as the second rotation member <NUM> is rotated.

<FIG> illustrates the state that the second rotation member <NUM> is downwardly rotated because the outer circumference of the second cam portion <NUM> pushes the second protrusion <NUM> when the ejector <NUM> is in the first position. At this time, since the protrusion <NUM> is inserted into a side of one end of the second rotation member, the groove <NUM> is hung in the protrusion <NUM> even through the groove <NUM> reaches the position of the protrusion <NUM>, whereby the second rotation member <NUM> cannot be rotated downwardly.

In this state, the arc shaped large gear portion <NUM> formed at the other end of the second rotation member <NUM> rotates the rotation force transfer gear <NUM> counterclockwise. Therefore, the full-ice sensing bar rotation gear <NUM> is rotated clockwise, and thus the full-ice sensing bar <NUM> descends to the downward position. At this time, since the magnet <NUM> is arranged at an opposite side of the full-ice sensing bar <NUM>, the magnet <NUM> approaches to the second hall sensor <NUM>, whereby a sensing signal is generated in the second hall sensor <NUM>.

<FIG> illustrates the state that the ejector <NUM> is rotated to the second position. At this time, the protrusion <NUM> is rotated and come out and at the same time the second cam portion <NUM> is also rotated and reaches the position of the second protrusion <NUM>. Therefore, the second protrusion <NUM> is inserted into the groove <NUM> of the second cam portion <NUM> by an elastic force of the second elastic member <NUM>, and the second rotation member <NUM> is upwardly rotated.

In this state, the arc shaped large gear portion <NUM> formed at the other end of the second rotation member <NUM> rotates the rotation force transfer gear <NUM> clockwise. Therefore, the full-ice sensing bar rotation gear <NUM> is rotated counterclockwise, and thus the full-ice sensing bar <NUM> ascends to the upward position. At this time, since the magnet <NUM> arranged at an opposite side of the full-ice sensing bar <NUM> is far away from the second hall sensor <NUM>, a sensing signal is stopped in the second hall sensor <NUM>.

As described above, during full-ice sensing operation, the full-ice sensing bar <NUM> moves from the position of <FIG> to the position of <FIG> and then senses full-ice while descending to the position of <FIG>.

When the ejector <NUM> is rotated for ice separation in a forward direction, the ejector rotation gear <NUM> is rotated clockwise (counterclockwise based on <FIG>) in <FIG>. At this time, since the protrusion <NUM> is hung in one end of the second rotation member <NUM>, the second rotation member <NUM> is not rotated, whereby the full-ice sensing bar <NUM> is maintained at a descending state as shown in <FIG>.

Next, a procedure of discharging ices and a control method of an ice maker will be described with reference to <FIG>.

First of all, if the ice maker <NUM> is initially driven, the rotation angle position of the ejector is identified using the first hall sensor, whereby the ejector <NUM> reaches the initial position.

Next, water of a predetermined content is supplied to the ice tray <NUM> and it is in a standby mode for a freezing time when water is frozen by the cool air. At this time, a temperature of the ice tray <NUM> may be measured through the temperature sensor <NUM>, whereby water has been completely phase-changed to ices.

Next, the full-ice sensing bar <NUM> is rotated to determine whether the ice bank <NUM> provided below the ice maker <NUM> is fully filled with ices. If it is determined that the ice bank <NUM> is fully filled with ices, it is periodically sensed whether the ice bank <NUM> is fully filled with ices, and it is in a standby mode in a state that ice separation is stopped until it is determined that the ice bank <NUM> is not fully filled with ices. To determine full-ice, the ejector is rotated in an opposite direction of the rotation direction of the ejector shown in <FIG>. That is, although the protrusion pins <NUM> of the ejector are rotated counterclockwise, the protrusion pins <NUM> are rotated clockwise to sense full-ice.

Next, if it is determined that the ice bank <NUM> is not fully filled with ices, the heater <NUM> is heated. The heater <NUM> is heated for a predetermined time before the ejector starts to be rotated. The heating operation may be performed continuously, may be performed intermittently at a predetermined period, or may be performed at a very short pulse period.

Next, when a predetermined time passes after the heater <NUM> is heated, or when the temperature of the ice tray <NUM>, which is measured by the temperature sensor, is a predetermined temperature or more, the ejector is rotated in a forward direction (clockwise) to separate ices in the ice tray <NUM> from the ice tray <NUM>.

At this time, the heater <NUM> continues to maintain a heating state even after the ejector <NUM> starts to be rotated, and is turned off before the ejector <NUM> turns to the initial position. That is, as described above, the first hall sensor <NUM> senses that the protrusion pins <NUM> of the ejector <NUM> reach the second position and turns off the heater <NUM> at that time.

When the ejector <NUM> is rotated for ice separation, since ices are already separated during rotation of <NUM>°, unnecessary operation of the heater may be reduced.

The ejector <NUM> may be rotated twice not one time during ice separation. The reason why that the ejector <NUM> is rotated twice is to make sure of complete ice separation in preparation for a case that ices may not be completely separated when the ejector <NUM> is rotated one time. Also, the ices separated from the ice tray may be hung between the protrusion pins <NUM> of the ejector <NUM> when the ejector <NUM> is rotated one time. As the ejector <NUM> is rotated twice, the ices separated from the ice tray may make sure of being dropped onto the ice bank <NUM>.

A method in which the time when ices are generated in the ice tray may be reduced and ice separation may easily be made will be described with reference to <FIG> and <FIG>.

An ice making method includes performing heat absorption through heat transfer by supplying the cool air generated by an evaporator to the ice tray for storing water of the ice maker, performing heat absorption through heat transfer between the ice tray and water, and making ices by reducing a temperature of water to a temperature of a freezing point or less. At this time, ice making performance of the refrigerator is determined by a speed of water received in the ice tray <NUM>, which is reduced to a certain temperature of a freezing point or less, and is improved if efficiency of the heat transfer is increased. Therefore, this method is focused on increase of efficiency of heat transfer between water and the cool air generated from the evaporator.

A method for increasing a contact electric heating area to increase heat transfer is here applied.

A protrusion portion <NUM> provided to be protruded toward an inner space and longitudinally extended along a rotation direction of the ices is provided in a cell which is one space partitioned by the partition rib <NUM>. <FIG> is a view illustrating a side cross-section of a cell, and <FIG> is a view illustrating a front cross-section of the ice tray.

Since the protrusion portion <NUM> is protruded toward an inner side of the cell, an inner area of the cell, which may be in contact with water, is increased. Therefore, the cool air supplied to the ice tray <NUM> may quickly be transferred to water through heat transfer with water received in the cell, and a generating speed of ices may be improved.

In <FIG>, ices made by the ice tray <NUM> are rotated to draw an arc from a direction 'c' to a direction 'b' by means of the protrusion pin <NUM> of the ejector <NUM> rotated counterclockwise, whereby the ices are dropped onto the lower end of the ice tray <NUM> through a space 'd'. Therefore, the protrusion portion <NUM> for increase of the electric heating area has a vertical cross-section to be matched with the rotation direction of the ices for a certain interval.

Also, since the protrusion portion <NUM> is protruded toward the inner side of the ice making space of the ice tray <NUM>, a water level of water supplied to the ice tray is increased as much as a volume of the protrusion portion <NUM>, whereby the volume of the protrusion portion <NUM> should be restricted such that a distance between the increased water level and the rotary shaft <NUM> is not shorter than a certain distance.

Also, a shape of the protrusion portion <NUM> becomes smaller in the portion 'b' of the ice than the portion 'c' of the ice, and a center of gravity should be given to a moving direction of the ices until the ices are dropped onto portion 'd', whereby the ices should be guided to be normally dropped. Therefore, a height of the protrusion portion <NUM> is preferably maintained such that the portion 'c' is higher than a normal water supply level and the portion 'b' is lower than the normal water supply level. At this time, the portion 'c' should be higher than a maximum water level such that the protrusion portion <NUM> may not act as a resistance when the ices move for ice separation.

It is preferable that the one cell is formed as a space having a certain radius with respect to the rotation direction of the ices. The protrusion pin <NUM> guides the ice made in the one cell to be pushed counterclockwise and discharged from the ice tray <NUM>. Since the protrusion pin <NUM> is a member having a certain size, the protrusion pin <NUM> uniformly pushes the ice even though the rotation position is varied in the cell. Therefore, if a radius in the cell is varied depending on the rotation angle of the protrusion pin <NUM>, a force of the protrusion pin <NUM>, which is applied to the ice, may be varied, whereby various difficulties may occur when the ices are discharged from the ice tray <NUM>.

However, since the cell is formed to have a certain radius therein, the force of the protrusion pin <NUM>, which is applied to the ice, may be maintained uniformly, whereby reliability in ice discharge may be improved.

Referring to <FIG>, the protrusion portion <NUM> includes a first protrusion <NUM> and a second protrusion <NUM>, which are spaced apart from each other at a certain interval. A recess <NUM> which is recessed is formed between the first protrusion <NUM> and the second protrusion <NUM>. The recess <NUM> may not be more recessed than the other portion of the bottom surface of the cell. That is, the recess <NUM> may be arranged to have a height lower than that of the upper end of the protrusion portion <NUM>.

The distance between the first protrusion <NUM> and the second protrusion <NUM> may be greater than the width of the protrusion pin <NUM>. If the protrusion pin <NUM> is rotated to rotate the ice, the protrusion pin <NUM> passes between the first protrusion <NUM> and the second protrusion <NUM>. To increase a contact area of the protrusion pin <NUM> with the ice when the protrusion pin <NUM> moves the ice in contact with the ice, it is preferable that one end of the protrusion <NUM> is downwardly extended to a height lower than the upper end of the protrusion portion <NUM>. In this case, if the protrusion portion <NUM> interrupts movement of the protrusion pin <NUM>, the ice cannot be discharged smoothly. Therefore, it is preferable that the protrusion pin <NUM> is not in contact with the protrusion portion <NUM>.

One end of the protrusion pin <NUM> is extended to be arranged between the protruded height of the protrusion portion <NUM> and the bottom surface of the cell. That is, one end of the protrusion pin <NUM> is extended to be arranged between the upper end of the protrusion portion <NUM> and the bottom surface of the recess <NUM>.

In the protrusion pin <NUM>, a portion close to the rotary shaft <NUM> has a relatively wide width, whereas a portion far away from the rotary shaft <NUM> may have a relatively narrow width. Therefore, when the protrusion pin <NUM> pushes the ice, the protrusion pin <NUM> may stably transfer the rotation force of the ejector to the ice.

Referring to <FIG>, the protrusion portion <NUM> may have an arc shape along an inner shape of the cell. That is, the protrusion portion <NUM> may be formed to make an arc along the bottom surface of the cell.

Extended heights at both ends of the protrusion portion <NUM> in the cell may be different from each other. That is, the protrusion portion <NUM> is arranged such that an angle of a start position based on a circle is asymmetrical to an angle of an end position based on the circle.

One end 400a of the protrusion portion <NUM> may be extended to be higher than the maximum water level of water supplied to the cell. A water supply valve for supplying water to the cell is controlled by a controller such that the amount of water supplied to the cell may not exceed the maximum water level. At this time, the controller may measure the amount of water by means of a flow rate sensor that passes through the water supply valve.

Therefore, one end 400a of the protrusion portion <NUM> is arranged to be higher than the ice frozen in the cell. In this case, the ice may be prevented from failing to move due to the protrusion portion <NUM> in which the ice is hung when the protrusion pin <NUM> rotates the ice in contact with the ice in an area adjacent to 'c' to move the ice. That is, since the ice of a portion adjacent to 'c' is frozen while having the shape of the protrusion portion <NUM>, the ice is not hung in the protrusion portion <NUM>.

Meanwhile, the portion 'c' means a portion where the protrusion pin <NUM> starts to be rotated in contact with the ice to discharge the ice from the ice tray <NUM>. In <FIG>, the protrusion pin <NUM> is rotated counterclockwise to discharge the ice.

The other end 400b of the protrusion portion <NUM> may be extended to be lower than the maximum water level of water supplied to the cell. That is, the other end 400b of the protrusion portion <NUM> is extended to a height lower than one end 400a of the protrusion portion <NUM>.

Also, the other end 400b of the protrusion portion <NUM> may be extended to be lower than the normal water level of water supplied to the cell. That is, the other end 400b of the protrusion portion <NUM> is extended to a height lower than one end 400a of the protrusion portion <NUM>.

In the portion adjacent to 'b', the protrusion portion <NUM> is extended to a height lower than the portion adjacent to 'c'. At this time, the portion adjacent to 'b' means an opposite portion of a portion where the protrusion pin <NUM> starts to be rotated in contact with the ice to discharge the ice from the ice tray <NUM>.

When the protrusion pin <NUM> pushes the ice and then reaches the position of 'b' based on <FIG>, the ice should be discharged to the portion 'd' by self-load after ascending to the upper side of the discharge guide <NUM> (see <FIG> and <FIG>). The discharge guide <NUM> has one side inclined to discharge the ice, and a center of gravity of the ice is preferably arranged in an inclined direction to smoothly discharge the ice.

Since the portion adjacent to 'c' is a portion positioned at the front of rotation and movement of the ice, a volume occupied by the protrusion portion <NUM> in the cell is reduced, and a volume occupied by water is increased. Therefore, the volume of the ice is more increased in the portion adjacent to 'c' in the cell than the portion adjacent to 'b', and the center of gravity of the ice when the ice moves is arranged in the portion where water is frozen in the portion adjacent to 'c'. Therefore, since the ice may easily move through the discharge guide <NUM>, reliability of ice discharge may be improved.

Meanwhile, the upper end of the protrusion portion <NUM> may be formed to be rounded to constitute a curve. Since the portion where the ice tray <NUM> is in contact with the ice is formed to be rounded, friction that may occur when the ice moves from the ice tray may be reduced.

<FIG> and <FIG> are views illustrating another example of <FIG>.

As shown in <FIG>, the upper end of the protrusion portion <NUM> may be formed to be angulated. Also, as shown in <FIG>, the upper end of the protrusion portion <NUM> may be formed to constitute a flat surface. The protrusion portion <NUM> may be formed in a shape that may be protruded into the cell to increase a contact area with water. It is preferable that the protrusion portion <NUM> is formed in a shape that does not increase resistance greatly when the ice moves inside the cell.

<FIG> is a view illustrating an example of a door provided with an ice maker, and <FIG> is a view illustrating a main portion in <FIG>.

The ice making compartment <NUM>, which may form ice to provide a user with the ice, is provided inside the refrigerating compartment door <NUM>.

The ice maker <NUM>, which may form ice, is provided at the upper side of the ice making compartment <NUM>, and the ice bank <NUM>, in which the ices discharged from the ice maker <NUM> are received, is provided at the lower portion of the ice maker <NUM>.

Meanwhile, an inlet <NUM> to which the cool air from the evaporator provided in the cabinet of the refrigerator is transferred is formed at one side of the door <NUM>. If the inlet <NUM> is in contact with a cool air discharge outlet provided in the cabinet, the cool air supplied from the cabinet may be supplied to the inlet <NUM>.

The cool air supplied through the inlet <NUM> may be supplied to the ice maker <NUM> and cool the water received in the ice tray <NUM> after passing through a cool air supply duct provided in the refrigerator compartment door <NUM>.

Meanwhile, the cool air discharged from the ice maker <NUM> is guided to a discharge outlet <NUM> after passing through the ice bank <NUM> and then passing through a cool air discharge duct provided in the refrigerating compartment door <NUM>. Since the air discharged from the discharge outlet <NUM> is in contact with a cool air collecting hole provided in the cabinet, the air may again be guided to the evaporator provided in the cabinet.

Although the ice making compartment <NUM> needs a temperature below zero to form ice, since the refrigerating compartment door <NUM> opens or closes the refrigerating compartment which maintains a temperature above zero, it is preferable that the air supplied to the ice making compartment <NUM> or discharged from the ice making compartment <NUM> is not discharged to the refrigerating compartment.

Therefore, a path that may move through the inlet <NUM> and the discharge outlet <NUM> is formed such that the cool air supplied to the refrigerating compartment door <NUM> and the cool air discharged from the refrigerating compartment door <NUM> may not leak to the storage compartment.

Meanwhile, the cool air supplied to the refrigerating compartment door <NUM> through the inlet <NUM> is guided to the upper side of the refrigerating compartment door <NUM>. On the other hand, the cool air which has passed through the ice maker <NUM> is guided from the inside of the refrigerating compartment door <NUM> to the lower side of the refrigerating compartment door <NUM>, whereby the cool air may be discharged through the discharge outlet <NUM>.

As shown in <FIG>, a cool air guide <NUM> for supplying the cool air to the lower portion of the ice maker <NUM> is provided at the lower portion of the ice maker <NUM>. An inlet <NUM> to which the cool air from the cool air supply duct provided inside the refrigerating compartment door <NUM> is transferred is provided at one side of the cool air guide <NUM>.

The cool air guide <NUM> is provided with a body <NUM> for guiding a path of the cool air, and the inlet <NUM> is arranged at the right side (based on <FIG>) of the body <NUM> and thus the cool air is guided from the body <NUM> in a left direction.

The body <NUM> includes a bottom surface <NUM>, of which upper side is provided with an opening portion <NUM>, whereby the cool air may upwardly be discharged toward the opening <NUM> without moving to the lower portion of the body <NUM>.

The bottom surface <NUM> is extended to be shorter than the width of the ice maker <NUM>. The cool air guided through the cool air guide <NUM> moves to the portion where the bottom surface <NUM> is formed, relatively stably in a left direction. However, if the cool air gets out of the portion where the bottom surface <NUM> is formed, the cool air moves relatively freely. Therefore, the cool air moves at a portion where the cool air gets out of the bottom surface <NUM>, in various directions, whereby the cool air may get out of resistance from the bottom surface <NUM>.

<FIG> is a view illustrating that an ice tray is viewed from the front, <FIG> is a view illustrating that a lower portion of an ice tray is viewed, and <FIG> is a view illustrating that an ice tray is viewed from a lower side.

In <FIG> and <FIG>, arrows represent a brief moving direction of the cool air supplied form the cool air guide <NUM>.

When the ice tray <NUM> is heated for ice separation, pins of the ice tray <NUM> are excessively increased, an electric heating area is increased, and a heating time is increased due to increase of heat capacity of the ice tray <NUM>. This may cause reduction of ice making amount, increase of ice making power consumption, and quality deterioration of ices due to melting of ice caused by heating of the heater. That is, since a heat transfer coefficient 'ha' for increase of ice making heat transfer amount is increased if a pressure drop amount on a cool air path is small, reckless pin attachment of the ice tray <NUM> may cause reduction of ice making air volume.

Further a method for discharging the cool air to a front surface of the ice tray <NUM> by allowing the cool air to enter a right side of the ice maker <NUM> and performing heat transfer from lower and front surfaces of the ice tray <NUM> is adopted. To increase ice making performance (ice making heat transfer amount) in the ice maker, pins are arranged for an electric heating area of the ice tray <NUM> and the cool air. However, if the pins are excessively arranged for increase of the electric heating area, a heating time for ice separation is increased due to increase of heat capacity according to increase of a total mass of the ice tray <NUM>, whereby ice making heat transfer efficiency is reduced. Also, a pressure drop amount of an ice making path is increased in accordance with arrangement of the pins, whereby heat transfer efficiency may be reduced. Therefore, the technology of lower and front surfaces of the ice tray has been devised considering the aforementioned technical restrictions.

Meanwhile, the cool air for ice making enters the ice tray <NUM> from the left side, cools the lower end of the ice tray <NUM> and then is discharged to the front surface of the ice tray <NUM>. At this time, since the driving device <NUM> for rotation of the ejector <NUM> exists at the left side of the ice tray, the path is blocked, whereby vortex occurs at the lower end of the ice tray <NUM>. Therefore, to minimize the vortex, the pins are removed from a certain area of the front surface, whereby efficiency in trade-off between the electric heating area and pressure drop is increased.

In case of the lower end of the ice tray <NUM>, a lot of heat transfer of the cool air occurs at the right side of the ice tray <NUM>, the right side of the ice tray <NUM> has the lowest temperature, whereas heat transfer is reduced at the left side of the ice tray <NUM> due to flow speed reduction and air temperature increase. Therefore, it is effective to arrange lower pins of the ice tray <NUM> at only a certain area. Also, staggered arrangement not in-line arrangement is applied to arrangement of the pins.

A first guide rib <NUM>, for heat exchange with the cool air supplied from the cool air guide <NUM>, a second guide rib <NUM> and a third guide rib <NUM> are arranged at the lower portion of the ice tray <NUM>.

The first guide rib <NUM> is arranged to be extended in a forward and backward direction with respect to the ice tray <NUM> and thus arranged to be vertical to the cool air supplied from the cool air guide <NUM> in a left direction. Also, the first guide rib <NUM> is downwardly protruded with respect to the ice tray <NUM>, whereby a contact area of the ice tray <NUM> with the cool air may be increased through the first guide rib <NUM> to quickly generate ices.

The second guide rib <NUM> is arranged to be extended in a left and right direction with respect to the ice tray <NUM> and thus arranged to be parallel with the cool air supplied from the cool air guide <NUM> in a left and right direction. Also, the second guide rib <NUM> is downwardly protruded with respect to the ice tray <NUM>, whereby the contact area of the ice tray <NUM> with the cool air may be increased through the second guide rib <NUM> to quickly generate ices.

Also, the second guide rib <NUM> may be arranged at the center of the lower portion of the ice tray <NUM> to guide a moving direction of the cool air supplied from the cool air guide <NUM>.

Meanwhile, the lower portion of the ice tray <NUM> may be categorized into a first area a1 arranged to adjoin the cool air guide <NUM> and a second area a2 arranged to be far away from the cool air guide <NUM>.

Since the first area a1 is arranged to be close to the cool air guide <NUM>, the first area a1 is a portion where a relatively fast speed of the cool air supplied from the cool air guide <NUM> is maintained. On the other hand, since the second area a2 is arranged to be far away from the cool air guide <NUM>, the second area a2 is a portion where the speed of the cool air supplied from the cool air guide <NUM> relatively becomes slow. If there are a lot of projected portions in the ice tray <NUM>, since the contact area of the ice tray <NUM> with the cool air is increased, it is advantageous in that heat exchange efficiency is increased, whereas a drawback occurs in that friction with the air is increased to make the moving speed of the air slow.

Therefore, in the area of a1, the second guide rib <NUM> is not provided, and the cool air is maintained at a relatively fast speed to easily move the cool air to the area of a2. On the other hand, since the speed of the cool air is lowered in the area of a2, the second guide rib <NUM> is provided to have more contact areas.

Meanwhile, the second guide rib <NUM> is arranged to be parallel with a left direction, to which the cool air moves, such that the moving speed of the cool air does not become slow if possible.

The third guide rib <NUM> is arranged to be extended in a left and right direction with respect to the ice tray <NUM> and arranged at lower corners of the ice tray <NUM>. The third guide rib <NUM> may form a lower outside of the ice tray <NUM>.

At this time, a barrier <NUM> is provided at the rear of the ice tray <NUM>. The barrier <NUM> may be arranged to be spaced apart from the third guide rib <NUM>.

The heater <NUM> may be arranged between the barrier <NUM> and the third guide rib <NUM>.

The third guide rib <NUM> guides the cool air to stay in the lower portion of the ice tray <NUM>, whereby a heat exchange time of the cool air with the ice tray <NUM> may be increased.

The third guide rib <NUM> may be arranged at both ends of the first guide rib <NUM>. That is, the third guide rib <NUM> may be arranged at a portion where the first guide rib <NUM> ends.

Each of the first guide rib <NUM> and the third guide rib <NUM> may be arranged as a plurality of the same. The third guide ribs <NUM> may be arranged to connect the first guide ribs <NUM> in a line. Therefore, the time when the cool air stays in the lower portion of the ice tray <NUM> is increased, whereby ice making efficiency may be improved.

The respective third guide ribs <NUM> may be arranged to be spaced apart from each other in a left and right direction. Since the portion where the heater <NUM> is arranged may partially be exposed between the third guide ribs <NUM>, the heater <NUM> may be cooled together with the third guide ribs <NUM>.

The plurality of first guide ribs <NUM> may be arranged, and the respective first guide ribs <NUM> may be arranged at the same interval. At this time, the second guide rib <NUM> may be arranged to connect two of the first guide ribs <NUM> to guide a flow of the cool air.

Particularly, the second guide rib <NUM> may be formed to be more protruded downwardly than the first guide rib <NUM>, and thus may guide the cool air in a certain direction while increasing the contact area with the cool air.

The second guide rib <NUM> may be arranged as a plurality of the same, and the respective second guide ribs <NUM> may be arranged alternately. Since the second guide ribs <NUM> are formed to be more protruded downwardly than the first guide rib <NUM>, it may be difficult for the cool air to move in a forward and backward direction between the second guide ribs <NUM>. Therefore, to enhance freedom of degree in the moving direction of the cool air, the second guide ribs <NUM> are arranged in staggered arrangement not in-line arrangement.

Fourth guide ribs <NUM> are provided on a front surface (see <FIG>) of the ice tray <NUM> and protruded to be extended in an up and down direction. The fourth guide ribs <NUM> are arranged in a third area b1 arranged to adjoin the cool air guide <NUM> in the ice tray <NUM>.

On the other hand, on the front surface of the ice tray <NUM>, a fourth area b2 arranged to be far away from the cool air guide <NUM> may have a flat shape. That is, since the fourth guide ribs <NUM> are not arranged in the fourth area b2, the fourth area b2 may constitute one surface.

The moving speed of the cool air is relatively fast in the third area b1 adjacent to the cool air guide <NUM> on the front surface of the ice tray <NUM>, whereas the moving speed of the cool air becomes slow in the fourth area b2 far away from the cool air guide <NUM>.

Therefore, the fourth guide ribs <NUM> are provided in the third area b1 to increase a heat exchange area with the cool air. On the other hand, the fourth area b2 may be formed as a flat surface, whereby the cool air may pass through the fourth area b2 without any delay.

Meanwhile, since some of the fourth guide ribs <NUM> are extended at different lengths to guide the cool air in various directions not a uniform direction.

The portion where the first area a1 and the second area a2 are divided from each other may be the same as or different from the portion where the third area b1 and the fourth area b2 are divided from each other.

The cool air guide <NUM> is arranged below the ice tray <NUM>, and the air guide <NUM> is arranged on the front surface of the ice tray <NUM> (see <FIG> and <FIG>). Although the air guide <NUM> is provided with the cool air discharge holes <NUM>, the space between the ice tray <NUM> and the air guide <NUM> is smaller than the lower space of the ice tray <NUM>. Therefore, based on that it is more difficult for the cool air to move on the front surface of the ice tray <NUM> than the lower portion of the ice tray <NUM>, less guide ribs are arranged on the front surface than the lower portion to improve heat exchange efficiency between the cool air and the ice tray.

<FIG> is a control block diagram illustrating one example, not part of the invention. Description will be given with reference to <FIG>.

In <FIG> a controller <NUM> receives information from various elements and transfers a related command in accordance with the received information. The controller <NUM> may be provided in the circuit board <NUM> of the ice maker <NUM>.

Unlike the above case, to concisely maintain the circuit board <NUM>, the controller may mean a controller for controlling the refrigerator. In this case, the controller <NUM> may together perform a function of driving a compressor for compressing a refrigerant, a function of transferring a related signal to a display provided in a door, and a function of transmitting and receiving a signal between an external communication network and the refrigerator.

Description will be given based on that it is applicable to both the aforementioned two examples (the example that the controller is provided in the circuit board and the example that the controller corresponds to a main controller of the refrigerator).

The controller <NUM> receives information on a temperature from the temperature sensor unit <NUM>. The controller <NUM> may determine whether the ice tray <NUM> has been sufficiently cooled, and may determine whether ice has been formed in the ice tray <NUM> in accordance with the sensed temperature.

The first sensor unit <NUM> may sense movement of the first rotation member in accordance with rotation of the ejector rotation gear. To this end, the first sensor unit <NUM> may include a first hall sensor <NUM> as shown in <FIG>. The first hall sensor <NUM> may sense a change of a magnetic force if the first rotation member moves, and therefore may sense rotation of the ejector. Therefore, the controller <NUM> may sense a rotation angle of the ejector <NUM> by means of the first sensor unit <NUM>.

The second sensor unit <NUM> may sense movement of the second rotation member in accordance with rotation of the ejector rotation gear. To this end, the second sensor unit <NUM> may include a second hall sensor <NUM> as shown in <FIG>. The second hall sensor <NUM> may sense a change of a magnetic force if the full-ice sensing bar rotation gear <NUM> moves together with the second rotation member, and therefore may sense rotation of the full-ice sensing bar rotation gear <NUM>. Therefore, the controller <NUM> may sense whether ices are stacked at a set amount or more, by means of the second sensor unit <NUM>.

A flow rate sensor <NUM> may sense the amount of water supplied to the ice tray <NUM>. Therefore, the controller <NUM> may sense the amount of water supplied to the ice tray <NUM> in accordance with a signal received from the flow rate sensor <NUM>.

The controller <NUM> may command the motor <NUM> to perform a forward rotation or backward rotation. That is, the motor <NUM> may rotate the ejector rotation gear clockwise or counterclockwise in accordance with the signal of the controller <NUM>.

The controller <NUM> may turn on or off the heater <NUM>. The controller <NUM> may heat the ice tray <NUM> by turning on the heater <NUM> in accordance with the rotation angle of the ejector. Also, the controller <NUM> may stop supply of heat to the ice tray <NUM> by turning off the heater <NUM> in accordance with the rotation angle of the ejector.

The controller <NUM> may open or close the water supply valve <NUM> for opening or closing the path where water is supplied to the ice tray <NUM> in accordance with flow rate information received from the flow rate sensor <NUM>. If the water supply valve <NUM> opens the path, water may be supplied to the ice tray <NUM>, and if the water supply valve closes the path, water is not supplied to the ice tray <NUM>.

<FIG> is a view illustrating an embodiment of a rotation path of an ejector, and <FIG> is a view illustrating an embodiment of an ejector rotation gear.

<FIG> illustrates that an embodiment described with reference to <FIG> is implemented, and <FIG> illustrates a method implemented in accordance with another embodiment. Likewise, rotation according to <FIG> may be implemented by an operation of the ejector rotation gear shown in <FIG>, and rotation according to <FIG> maybe implemented by the ejector rotation gear shown in <FIG>.

The embodiment according to <FIG> and <FIG> will be described. If ice making is completed in the ice tray <NUM>, the ejector <NUM> is rotated from the first position to the second position counterclockwise to identify full-ice of the ice bank <NUM>. At this time, although the protrusion pin <NUM> is rotated together with the ejector <NUM>, the full-ice sensing bar rotation gear <NUM> is substantially rotated to sense full-ice.

In this case, as the ejector rotation gear <NUM> shown in <FIG> is rotated clockwise, and the first rotation member <NUM> is hung in the second groove <NUM>. Therefore, the first sensor unit <NUM> may sense movement of the first rotation member <NUM>, and may finally sense that the protrusion pin <NUM> moves to the second position.

Subsequently, the controller <NUM> provides a rotation force of the motor <NUM> rotated counterclockwise, whereby the ejector <NUM> is rotated counterclockwise. That is, the protrusion pin <NUM> moves from the second position to the first position. Likewise, since the first rotation member <NUM> is hung in the first groove <NUM>, the first sensor unit <NUM> may sense movement of the first rotation member <NUM>, and may finally sense that the protrusion pin <NUM> moves to the first position. The first position may mean the initial position.

At the first position, if a certain time passes after the heater <NUM> is turned on, the protrusion pin <NUM> moves to the third position counterclockwise due to the rotation force of the motor <NUM>. The protrusion pin <NUM> continues to push the ice until the surface of the ice is melted and then the ice moves. If the surface of the ice is melted and the ice moves after a certain time passes, the protrusion pin <NUM> moves by continuously pushing the ice. Even at this time, the heater <NUM> is continuously driven, and heats the ice tray <NUM>. If the heater <NUM> is driven, since a current is supplied to the heater <NUM>, the heater <NUM> consumes energy.

If the protrusion pin <NUM> pushes the ice while being rotated counterclockwise and finally reach the second position, the heater <NUM> is turned off. That is, no current is supplied to the heater <NUM>, and energy consumption is stopped.

Subsequently, if the protrusion pin <NUM> reaches the first position while being rotated counterclockwise, it is determined that ice separation of the ice tray <NUM> is completed.

Unlike the embodiment according to <FIG> and <FIG>, the first cam portion <NUM> of the ejector rotation gear is additionally provided with a third groove <NUM> in the embodiment according to <FIG> and <FIG>. That is, the first cam portion <NUM> are provided with the first groove <NUM>, the second groove <NUM> and the third groove <NUM>.

If the first rotation member <NUM> is hung in each of the first, second and third grooves <NUM>, <NUM> and <NUM>, the first sensor unit <NUM> senses a position change of the first rotation member <NUM>. Therefore, the first sensor unit <NUM> may sense how the ejector <NUM>, that is, the protrusion pin <NUM> is rotated to reach the current position and an angle at the current position.

In this embodiment, the ejector rotation gear <NUM> is rotated from the first position to the second position in the same manner as the embodiment of <FIG> and <FIG> to sense full-ice. Therefore, the protrusion pin is rotated from the first position to the second position clockwise.

If the ices are stacked in the ice bank <NUM> at a height lower than the set height, the ejector <NUM> is rotated counterclockwise. The protrusion pin <NUM> moves from the second position to the first position, and continue to be rotated counterclockwise and then move to the third position.

At this time, the first sensor unit <NUM> senses the time when the first rotation member <NUM> is hung in the first groove <NUM> (when the first rotation member <NUM> reaches the first position), whereby the heater <NUM> is turned on at the corresponding time.

If the protrusion pin <NUM> is rotated counterclockwise to reach the third position and continuously push the ice, the ice starts to move by means of the protrusion pin <NUM>.

Meanwhile, if the protrusion pin <NUM> continues to be rotated counterclockwise, the ice move and the protrusion pin <NUM> reaches the fourth position. If the ice moves to the fourth position, the ice is substantially separated from the ice tray <NUM>, whereby the ice may move by means of only the rotation force of the protrusion pin <NUM> even though heat is not supplied from the heater <NUM>.

The time when the protrusion pin <NUM> reaches the fourth position is the same as the time when the first rotation member <NUM> is hung in the third groove <NUM>. That is, if the ejector rotation gear <NUM> continues to be rotated counterclockwise, the ejector, that is, the protrusion pin <NUM> is rotated counterclockwise together with the ejector rotation gear <NUM>. If the first rotation member <NUM> is hung in the third groove <NUM>, the first rotation member <NUM> moves, and the first sensor unit <NUM> may sense the corresponding time.

The controller <NUM> may determine that the heater <NUM> does not need to supply heat because the protrusion pin <NUM> sufficiently pushes the ice at the corresponding time, and may turn off the heater <NUM>, whereby energy may be saved.

In the embodiment of <FIG> and <FIG>, the heater <NUM> is turned off at an earlier time as compared with the embodiment of <FIG> and <FIG>. That is, power consumption in the heater <NUM> may be reduced. If the power consumed by the heater <NUM> is increased, since the ice tray <NUM> is also heated by a high temperature, more energy is consumed to again cool the ice tray <NUM> to form the ice.

In the embodiment of <FIG> and <FIG>, energy consumed by the heater and energy consumed to cool the ice tray may be reduced as compared with the embodiment of <FIG> and <FIG>. Also, in the embodiment of <FIG> and <FIG>, since the temperature of the ice tray is not increased as compared with the embodiment of <FIG> and <FIG>, the ice tray may be cooled more quickly. Therefore, since the time required to form the ice may be reduced, the amount of the ice that may be provided to the user may be increased.

A structure that the position (the position of the protrusion pin <NUM> between <NUM>° and <NUM>°) where the ejector starts to move from the third position may be sensed is applied to the embodiment of <FIG> and <FIG>, and the heater <NUM> may be turned off relatively quickly.

Generally, for ice separation from the ice tray <NUM>, the heater <NUM> at the lower end of the ice tray <NUM> is used. If the protrusion pin <NUM> starts to move the ice beyond the third position, since the surface of the ice is melted even though the heater <NUM> is turned off, ice separation may be performed.

<FIG> is a view illustrating another embodiment of an ejector rotation gear.

Referring to <FIG>, the ejector rotation gear <NUM> includes the first groove <NUM>, the third groove <NUM> and a protrusion <NUM> on the outer circumference of the first cam portion <NUM>.

The initial position of the ejector is sensed by movement of the first rotation member <NUM>, which is generated in the first groove <NUM>, and a full-ice position is sensed by movement of the first rotation member <NUM>, which is generated in the second groove <NUM>.

On the other hand, the time when the heater <NUM> is turned off is sensed by movement of the first rotation member <NUM>, which is generated in the protrusion <NUM>.

If the first rotation member <NUM> is hung in the first groove <NUM> and the second groove <NUM>, a position change of the first rotation member <NUM> is sensed by the first hall sensor <NUM> of the first sensor unit <NUM>.

The first sensor unit <NUM> further includes a third hall sensor <NUM> packaged in the circuit board <NUM>. The third hall sensor <NUM> is arranged above the first hall sensor <NUM>.

If the first rotation member <NUM> is hung in the protrusion <NUM>, since the first rotation member ascends, the third hall sensor <NUM> may sense movement of the first rotation member <NUM>.

That is, in this embodiment, it is designed such that the protrusion <NUM> is added to allow the first rotation member <NUM> to ascend. The first sensor unit <NUM> may sense whether the ejector has reached the initial position, by means of the first hall sensor <NUM>, and may sense whether the ejector has reached the position where the heater may be turned off, by means of the third hall sensor <NUM>.

In this embodiment, since the first sensor unit includes two hall sensors, a first group of the initial position and the full-ice position may be identified from a second group of a position where the heater may be turned off.

In addition, in another embodiment, the off-time of the heater <NUM> may be determined by measurement of the current supplied to the motor <NUM>. Since the ice does not move initially at the third position corresponding to the time when the protrusion pin <NUM> is rotated to reach the ice, stall occurs, and a current value supplied to the motor <NUM> is increased. If the ice starts to move, stall is released and the protrusion pin <NUM> is rotated, and a current value consumed by the motor <NUM> is reduced. The time when the current consumed by the motor <NUM> is determined, and it is determined at that time that ice separation may be performed even though heat is not additionally supplied from the heater, whereby the heater may be turned off.

That is, the first sensor unit <NUM> may sense the angle of the protrusion pin <NUM> before the ice formed in the ice tray <NUM> is completely discharged from the ice tray <NUM>. The first sensor unit <NUM> may sense whether the ice passes through a specific position of a rotation track of the protrusion pin <NUM> even before the ice is completely discharged, by sensing whether the protrusion pin <NUM> have reached a specific angle. Meanwhile, the heater <NUM> is turned off at the angle sensed by the first sensor unit <NUM>. That is, since the heater <NUM> is
turned off before the ice is completely discharge from the ice tray <NUM>, energy consumed for driving the ice maker may be saved.

Meanwhile, the first sensor unit <NUM> may sense whether the protrusion pin <NUM> has reached an angle before the ice ascends to the discharge guide <NUM>, and may turn off the heater <NUM> at the corresponding angle. After the ice ascends to the discharge guide <NUM>, the ice may be dropped along a slope of the discharge guide <NUM> and stored in the ice bank <NUM>.

Also, the first sensor unit <NUM> may sense whether the protrusion pin <NUM> has reached an angle which has rotated the ice formed by the ice tray at <NUM>° or less, thereby turning off the heater <NUM> at the corresponding angle. Since the ice moves from the ice tray in a state that the ice is rotated at <NUM>° or less, the ice may move without melting by additionally supplying heat from the heater <NUM>.

The first sensor unit <NUM> may sense whether the protrusion pin <NUM> has reached an angle before the protrusion pin <NUM> is arranged to be vertical to the ground after being in contact with the ice formed by the ice tray, and thus may turn off the heater <NUM> if the protrusion pin <NUM> reaches the corresponding angle. Since the time when the heater is turned off may become faster, energy consumed by the ice maker may be saved, and the time required to cool the ice maker may be saved.

Also, the first sensor unit <NUM> may sense whether the protrusion pin <NUM> has reached an angle for moving the ice formed by the ice tray <NUM> at a certain angle, and thus may turn off the heater <NUM> at the corresponding angle.

The first sensor unit <NUM> may sense whether the protrusion pin <NUM> has moved the ice formed by the ice tray at a predetermined angle after the heater <NUM> has been driven, and thus may turn off the heater <NUM>.

The first sensor unit <NUM> may sense a first position, a second position and a third position according to the rotation angle of the protrusion pin <NUM>, wherein the angle of the protrusion pin rotated at the first position, the second position and the third position are different from one another. In this case, if the protrusion pin <NUM> reaches the third position, the heater <NUM> may be turned off.

Meanwhile, the first position may be the initial position where ice separation starts, the second position may be the position where full-ice of the ice bank is sensed, and the third position may be the position where the ice formed by the ice tray moves at a predetermined distance.

If the first sensor unit <NUM> senses that the protrusion pin <NUM> has reached the first position, the heater <NUM> is turned on, whereby ice separation may start.

<FIG> is a view illustrating an effect of the embodiments described in <FIG> and <FIG>.

The experimental result according to the embodiment of <FIG> and <FIG> is shown in <FIG>, and the experimental result according to the embodiment of <FIG> and <FIG> is shown in <FIG>.

In <FIG>, a bar graph means a heating time of the heater, and a line means ice making amount.

According to the experimental result of the embodiment according to <FIG> and <FIG>, additional heating of about <NUM> seconds may be avoided by the heater <NUM> as compared with the embodiment according to <FIG>. Therefore, it is noted that the heating time by the heater is reduced to <NUM>.

Claim 1:
An ice maker comprising:
an ice tray (<NUM>) for receiving water to form ice;
a motor (<NUM>) capable of performing forward and backward rotation;
an ejector (<NUM>) rotating ice formed by the ice tray to discharge the ice from the ice tray, the ejector (<NUM>) including a rotary shaft (<NUM>) rotatable by being axially connected to the motor (<NUM>) and a protrusion pin (<NUM>) protruded in a radius direction of the rotary shaft;
a heater (<NUM>) for selectively supplying heat to the ice tray (<NUM>); and
a first sensor unit (<NUM>) for sensing a rotation angle of the protrusion pin (<NUM>),
wherein the first sensor unit (<NUM>) is controlled to sense a second preset rotation angle of the protrusion pin (<NUM>) and the heart (<NUM>) is controlled to be turned on at the second preset rotation angle sensed by the first sensor unit (<NUM>), characterised in that
the first sensor unit (<NUM>) is controlled to sense a preset rotation angle of the protrusion pin (<NUM>) after rotation of the protrusion pin (<NUM>) from the second present rotation to move the ice before the ice formed by the ice tray (<NUM>) is completely discharged from the ice tray (<NUM>), and the heater (<NUM>) is controlled to be turned off at the preset rotation angle sensed by the first sensor unit (<NUM>).