Patent Description:
In general, a refrigerator is a household appliance capable of keeping food fresh for a long time by having a storage compartment storing the food and a cold air supply device supplying cold air to the storage compartment.

A temperature inside the refrigerator is lower than a temperature outside the refrigerator, and dew may thus be formed inside the refrigerator in case that the door is opened. A heater has been conventionally installed on a door frame to prevent such a dew formation phenomenon.

<CIT> discloses a refrigerator comprising a plurality of heaters configured to efficiently prevent formation of dew on the door and home bar door.

JPS52 <NUM> U discloses a refrigerator configured to reduce power consumption of a dew preventing heater.

<CIT> discloses a refrigerator door comprising a heater configured to prevent dew forming on the door.

However, the heater is operated at the same position with the same power irrespective of an environment inside and outside the refrigerator, and is thus unable to efficiently remove the dew from the refrigerator.

Embodiments of the disclosure overcome the above disadvantages and other disadvantages not described above. In addition, the disclosure is not required to overcome the disadvantages described above, and an embodiment of the disclosure may not overcome any of the problems described above.

According to an aspect of the present invention, there is provided a refrigerator according to claim <NUM> and a control method of a refrigerator according to claim <NUM>.

The second heating wires are arranged extending to at least one of an upper side edge or a lower side edge, adjacent to the side edge.

The processor is configured to determine an operating duty of each of the first heating wires and the second heating wires based on at least one of a difference between temperatures inside and outside the refrigerator, and the humidity outside the refrigerator.

The processor is configured to determine an operating mode of the refrigerator based on at least one of the temperature and the humidity, measured by the sensor, and is configured to allow only the first heating wires to be driven in case that the determined operating mode is a normal mode and allow the first heating wires and the second heating wires to be driven together in case that the determined operating mode is a high temperature and high humidity mode.

The first heating wires and the second heating wires have heating performances different from each other.

The planar heater includes: a base film, a plurality of heating wires including the first and second heating wires and printed on one surface of the base film, a protective film laminated on the one surface of the base film to protect the plurality of heating wires; and a double-sided tape attached to the protective film.

The plurality of heating wires are printed with silver (Ag) nano ink.

The base film includes polyethylene terephthalate (PET) material.

The protective film includes ethylene-vinyl acetate copolymer (EVAC) material.

The door includes an inner door having an opening and an outer door pivoted in front of the inner door to open and close the opening, and the planar heater is installed on the inner door.

The control method of a refrigerator further comprises determining an operating mode of the refrigerator based on the measured temperature and humidity, wherein in the driving of the heating wires, only the first heating wires are driven in case that the determined operating mode is a normal mode, and the first heating wires and the second heating wires are driven together in case that the determined operating mode is
a high temperature and high humidity mode.

Additional and/or other aspects and advantages of the disclosure are set forth in part in the description which follows and, in part, are obvious from the description, or may be learned by practice of the disclosure.

The above and/or other aspects of the disclosure are more apparent by describing certain embodiments of the disclosure with reference to the accompanying drawings, in which:.

Embodiments described below are illustratively described to assist in understanding of the disclosure, and it is to be understood that the disclosure may be variously modified and executed unlike the embodiments described herein. However, if it is decided that a detailed description for the known functions or components related to the disclosure may obscure the gist of the disclosure, the detailed description and concrete illustration are omitted. Further, the accompanying drawings are not illustrated to scale, but sizes of some of components may be exaggerated to assist in the understanding of the disclosure.

Terms used in the specification and claims are selected as general terms in consideration of the functions in the disclosure. However, these terms may be changed depending on the intention of those skilled in the art, legal or technical interpretation, the emergence of a new technique and the like. In addition, some terms arbitrarily chosen by an applicant may exist. In this case, the meanings of such terms are mentioned in detail in corresponding description portions of the disclosure. Therefore, unless defined in detail, these terms may be interpreted on the basis of the contents throughout the disclosure and common technical knowledge in the art unless defined in detail.

In the disclosure, an expression 'have', 'may have', 'include', 'may include' or the like, indicates existence of a corresponding feature (for example, a numerical value, a function, an operation, a component such as a part or the like), and does not exclude existence of an additional feature.

In addition, the disclosure describes components necessary for the description of each embodiment of the disclosure, and is not necessarily limited thereto. Therefore, some components may be changed or omitted, and other components may be added. In addition, the components may also be distributed and arranged in independent devices different from each other.

Further, the embodiments of the disclosure are described in detail with reference to the accompanying drawings and contents described in the accompanying drawings, but the disclosure is not limited or restricted to the embodiments.

The disclosure provides a refrigerator having an improved heater structure to prevent a dew formation phenomenon.

Hereinafter, the disclosure is described in more detail with reference to the accompanying drawings.

<FIG> is a perspective view of a refrigerator <NUM> according to an embodiment of the disclosure. <FIG> is an enlarged perspective view of the refrigerator with a second door <NUM> opened.

Referring to <FIG> and <FIG>, the refrigerator <NUM> may include: a body <NUM>; doors <NUM>, <NUM> and <NUM>; drawers <NUM> and <NUM>; and hinges <NUM>.

The refrigerator <NUM> may be a device for storing food or drugs at a predetermined temperature to chill or not to spoil the food or drugs. The refrigerator <NUM> is shown in a shape of a general household refrigerator, but is not limited thereto. The refrigerator <NUM> may be a kimchi refrigerator, alcohol refrigerator, cosmetic refrigerator, etc..

The body <NUM> may have a shape of an approximately rectangular parallelepiped with an open front surface, but is not limited thereto and may be formed in various sizes and shapes.

<FIG> shows that the refrigerator <NUM> has the doors <NUM> and <NUM> on both sides of its upper portion and the drawers <NUM> and <NUM> on its lower portion, but the refrigerator <NUM> is not limited thereto. Depending on a layout of the doors <NUM> and <NUM>, drawers <NUM> and <NUM> and storage compartments <NUM>, <NUM> and <NUM>, the refrigerator <NUM> may be a French door type, a side-by-side type, etc..

The body <NUM> may have the storage compartments <NUM>, <NUM> and <NUM> which are formed inside the body <NUM> and open by the opening and closing doors <NUM>, <NUM> and <NUM> to store water, beverages and refrigerated or frozen food.

The body <NUM> may include an inner case (not shown) forming the storage compartments <NUM>, <NUM> and <NUM>, an outer case (not shown) forming the outside of the refrigerator and an insulating material (not shown) maintaining a temperature difference between the inner case and the outer case.

The insulating material may prevent cold air inside the storage compartments <NUM>, <NUM> and <NUM> from leaking to the outside, and prevent outside heat from entering the storage compartments <NUM>, <NUM> and <NUM>.

The storage compartments <NUM>, <NUM> and <NUM> may be divided from one another by partitions disposed inside the body <NUM>. The storage compartments <NUM>, <NUM> and <NUM> may be divided into freezer compartments <NUM> and <NUM> respectively disposed at the lower portion of the refrigerator <NUM> and a refrigerator compartment <NUM> disposed at its upper portion. However, the freezer compartments <NUM> and <NUM> and the refrigerator compartment <NUM> are not limited to this arrangement, and may be arranged in reverse positions.

The first door <NUM> may open and close a portion of a front surface of the storage compartment <NUM> by being pivoted at an angle (e.g. <NUM>° or less) determined by hinges 70a and 70b.

The first door <NUM> may display functions and settings of the refrigerator <NUM> on its surface, and may include an operation panel <NUM> changeable by a user's input (e.g., touch or button selection), a dispenser <NUM> for providing water, ice or carbonated water, and/or a graspable handle <NUM>.

The second door (or outer door) <NUM> and/or the third door (or inner door) <NUM> may be respectively pivoted at an angle (e.g., <NUM>° or less) determined by hinges 70c to 70f, to open and close the other portion of the front surface of the storage compartment <NUM>.

The second door <NUM> may include a graspable handle <NUM>. The handle <NUM> of the first door <NUM> and the handle <NUM> of the second door <NUM> may be positioned to be spaced apart from each other with respect to a central area of the storage compartment <NUM>.

The second door <NUM> and the third door <NUM> opening and closing the other portion of the first storage compartment <NUM> may be installed as double doors. However, the disclosure is not limited thereto, and the first door <NUM> and its adjacent door may be installed as double doors.

The second door <NUM> may be relatively pivotally coupled to the third door <NUM>. That is, the second door <NUM> may be opened or closed independently from the third door <NUM>, and may be opened or closed together with the third door <NUM>.

The third door <NUM> may include an opening corresponding to the other portion of the first storage compartment <NUM>. The opening of the third door <NUM> may be opened or closed by the second door <NUM>.

In case that the second door <NUM> is opened by the user, a door guard <NUM> installed in the opening of the third door <NUM> may be exposed to the outside. The door guard <NUM> may include a plurality of shelves capable of storing the food, and may be detachably coupled to the third door <NUM>.

The user may open only the second door <NUM>, and may easily access the food and the like, stored in the door guard <NUM>. In addition, the leakage of the cold air to the outside of the refrigerator <NUM> in case that only the second door <NUM> is opened may be reduced than in case that the second door <NUM> and the third door <NUM> are opened together.

As described above, the second door <NUM> and the third door <NUM> may be disposed double, and each door may be configured to be able to be pivoted relatively to each other. Accordingly, the food may be put in and out in various ways based on the user's need, and the leakage of the cold air may be minimized.

Meanwhile, in case that the second door <NUM> and the third door <NUM> are closed, the third door <NUM> may maintain a low temperature by the cold air supplied to the inside of the first storage compartment <NUM>. In case that the user opens the second door <NUM>, dew may be formed on a front surface of the third door <NUM> due to a temperature difference between the third door <NUM> and the outside air.

As described below, this dew formation phenomenon may be resolved by installing a planar heater <NUM> (see <FIG>) along an edge of the third door <NUM>.

<FIG> is a perspective view of the third door <NUM> from which the door guard <NUM> is separated. Referring to <FIG>, the third door <NUM> may include a door frame <NUM> having the opening, an upper frame <NUM> and a lower frame <NUM> respectively disposed on upper and lower sides of the third door <NUM> and a guard support <NUM> coupled to a rear side of the door frame <NUM>.

A foam space (not shown) may be formed between the door frame <NUM> and the guard support <NUM>, and an insulating material may be foamed in the foam space.

The planar heater <NUM> may be installed on a back surface of the door frame <NUM> to remove the dew formation. The planar heater <NUM> may receive power by being connected to a power supply (or coil driving device) positioned inside the body <NUM>.

The planar heater <NUM> may be installed to generate heat by receiving the power. In case that the first planar heater <NUM> is heated up, a temperature of the door frame <NUM> may be increased. Accordingly, the temperature difference between the door frame <NUM> and the outside air may be decreased, thereby preventing the dew formation.

The planar heater <NUM> may have the form of a film and may be attached to the back surface of the door frame <NUM>. One surface of the planar heater <NUM> may have an adhesive surface having adhesive strength. Without any separate fastening mechanism, the planar heater <NUM> may be attached to the back surface of the door frame <NUM> using the adhesive strength of the adhesive surface.

The planar heater <NUM> may be attached along an outer edge of the door frame <NUM>. The planar heater <NUM> may be disposed adjacent to a gasket (not shown) of the second door <NUM>, which is installed in front of the door frame <NUM>. In detail, the planar heater <NUM> may be disposed adjacent to an outer rim of the gasket. The planar heater <NUM> may be disposed in this manner because the dew may generally be formed on an outer rim of the door frame <NUM>, adjacent to the gasket of the outer door.

<FIG> is a front view of the planar heater <NUM> in which a plurality of heating wires <NUM> (shown as 120a and 120b in <FIG>) are arranged. Referring to <FIG>, the planar heater <NUM> may have an opening <NUM> corresponding to the opening of the third door <NUM>, and may have an overall shape corresponding to that of the third door <NUM>.

The planar heater <NUM> may have the form of the film. The planar heater <NUM> may include a base film <NUM> (see <FIG>), heating wires <NUM> (shown as 120a and 120b in <FIG>) printed on the base film and a terminal <NUM> (shown as 150a and 150b in <FIG>) for supplying the power to the heating wires <NUM> from an external power source (not shown).

The heating wires <NUM> may be printed on the base film, and may thus maintain a predetermined interval therebetween and be arranged in a specific shape in a fixed position. Therefore, it is possible to prevent a short-circuit between the heating wires <NUM>, and easily manufacture the planar heater <NUM>.

The planar heater <NUM> may have a separate opening <NUM> formed in a portion where a latch of the third door <NUM> is disposed. Through this opening, the planar heater <NUM> may be attached to the door frame <NUM> without interference of the latch.

The planar heater <NUM> includes a plurality of heating wires <NUM>. In detail, the planar heater <NUM> includes first heating wires 120a arranged to surround an edge of the planar heater <NUM> and second heating wires 120b arranged on only one portion of the edge of the planar heater <NUM>.

However, the number of the heating wires <NUM> is exemplary and is not limited thereto. Additional heating wires <NUM> may be arranged based on temperature and humidity outside the refrigerator <NUM>, a degree of the dew formation, etc..

It is possible to have the same effect as having a plurality of planar heaters by arranging the plurality of heating wires <NUM> on one film. In detail, the plurality of heating wires <NUM> may be printed on the one film, and high heating effect may thus be expected with neither a complicated inner structure of the third door <NUM> nor an increased thickness of the third door <NUM>.

The second heating wires 120b are arranged on a side edge of the door, most spaced apart from the hinges 70e and 70f respectively connecting the third door <NUM> and the body <NUM> to each other. The side edge may be a portion where a difference between the temperatures inside and outside the third door <NUM> is the largest as the second door <NUM> is opened.

That is, the second heating wires 120b arranged on the side edge may be driven to intensively generate the heat in a region where the dew may be easily formed, thereby effectively preventing the dew formation phenomenon.

In particular, the second heating wires are arranged not on the entire edge of the door but on only a portion thereof. Accordingly, the second heating wires may have lower power consumption than the first heating wires, and may be operated in conjunction with or independently from the first heating wires as described below, thereby more efficiently preventing the dew formation phenomenon.

However, the second heating wires 120b are not limited to this arrangement, and may be arranged extending to at least one of an upper side edge or a lower side edge, adjacent to the side edge. In addition, it is also possible to experimentally find a position where the most dew is formed on the third door <NUM> and arrange the second heating wires 120b intensively on that position.

In addition, as shown in the drawing, the heating wires <NUM> may be formed in a zigzag shape in which some sections thereof have winding curves. The heating wires <NUM> may tend to have its length and heat generation amount proportional to each other. Therefore, it is possible to effectively prevent the dew formation phenomenon in case that the heating wires <NUM> have the zigzag shape to have a long length in a region where the dew may be easily formed due to the large difference between the temperatures inside and outside the refrigerator <NUM>.

In addition, the first heating wires 120a and the second heating wires 120b may have heating performances different from each other. For example, the first heating wires 120a may have a heating performance of <NUM> watt (W) and the second heating wires 120b may have that of <NUM> watt (W), but such heating performances are exemplary and may be set in various ways based on a surrounding environment, a target temperature of the refrigerator <NUM>, etc..

That is, the plurality of heating wires <NUM> may have the heating performances different from each other, and may thus perform heat-generating operation in various cases based on the environment outside the refrigerator <NUM>, thereby effectively preventing the dew formation phenomenon.

The refrigerator <NUM> includes: a sensor (not shown) configured to measure at least one of temperature and humidity outside the refrigerator <NUM>; and a processor (not shown) configured to control driving of at least one of the first heating wires 120a and the second heating wires 120b based on a measured value of the sensor.

In detail, the processor may be configured to determine an operating duty of each of the first heating wires 120a and the second heating wires 120b based on at least one of a difference between temperatures inside and outside the refrigerator <NUM>, and the humidity outside the refrigerator <NUM>, measured by the sensor.

The operating duty of each of the heating wires <NUM> may refer to a time ratio in which the heating wires <NUM> are driven per unit time. In detail, the heating wires <NUM> may not be simply driven in both ON/OFF states, but the driving time ratio may be variously determined based on a condition outside the refrigerator <NUM>.

In detail, in case of determining the operating duty of each of the heating wires based on the measured value received from the sensor, the processor may allow a pulse width modulation (PWM) signal corresponding to the determined operating duty to be output. Accordingly, a current corresponding to the operating duty may flow from the external power source to each of the heating wires <NUM>.

For example, in case that the environment outside the refrigerator <NUM> has high temperature and high humidity and the dew may thus be easily formed on the third door <NUM>, the sensor may transmit information on the temperature and/or humidity outside the refrigerator to the processor, and the processor may determine a high operating duty of each of the heating wires <NUM> (for example, <NUM>% and <NUM>% may be the respective operating duties of the first heating wires and the second heating wires).

Meanwhile, in case that the environment outside the refrigerator <NUM> has low temperature and low humidity and the dew may thus be hardly formed on the third door <NUM>, the sensor may transmit the information on the temperature and/or humidity outside the refrigerator to the processor, and the processor may determine a low operating duty of each of the heating wires <NUM> (for example, <NUM>% and <NUM>% may be the respective operating duties of the first heating wires and the second heating wires).

That is, the processor may flexibly determine the operating duties of the plurality of heating wires <NUM> based on the environment outside the refrigerator <NUM>, thereby improving its energy efficiency. In addition, the processor may individually control the plurality of heating wires <NUM> arranged on positions different from each other to intensively heat a region vulnerable to the dew formation phenomenon (for example, a region where the second heating wires 120b are disposed), thereby efficiently preventing the dew formation phenomenon.

In addition, the processor may be configured to determine an operating mode of the refrigerator based on at least one of the temperature and the humidity, measured by the sensor, and may be configured to allow only the first heating wires 120a to be driven in case that the determined operating mode is a normal mode and allow the first heating wires 120a and the second heating wires 120b to be driven together in case that the determined operating mode is a high temperature and high humidity mode.

That is, in case that the temperature or humidity outside the refrigerator <NUM> is lower than a predetermined value, the processor may determine the operating mode as the normal mode and allow only the first heating wires 120a to be driven.

Meanwhile, in case that the temperature or humidity outside the refrigerator <NUM> is higher than the predetermined value, the processor may determine the operating mode as the high temperature and high humidity mode and allow the first heating wires 120a and the second heating wires 120b to be driven together.

Through the above-described control manner of the processor, it is possible to prevent unnecessary power waste of the planar heater <NUM>, and achieve flexible and efficient power consumption in response to the environment outside the refrigerator <NUM>.

<FIG> is a cross-sectional view taken along line I-I of <FIG>. Referring to <FIG>, the planar heater <NUM> may include: the base film <NUM>; heating wires <NUM> printed on one surface of the base film <NUM> by gravure printing; a protective film <NUM> laminated on the one surface of the base film <NUM> to protect the heating wires <NUM>; and a double-sided tape <NUM> attached to the protective film <NUM>.

The base film <NUM> may be disposed on one surface of the planar heater <NUM>, and the double-sided tape <NUM> may be disposed on the other surface of the planar heater <NUM>. The other surface of the planar heater <NUM> on which the double-sided tape <NUM> is disposed may have the adhesive strength due to the double-sided tape <NUM>, and may thus be easily adhered and fixed to the door frame <NUM>.

The base film <NUM> may include polyethylene terephthalate (PET) material.

The heating wires <NUM> may receive the current and generate the heat. The heating wires <NUM> may be printed with silver (Ag) nano ink.

The protective film <NUM> may include polyethyleneterephthalate (PET) and ethylene-vinyl acetate copolymer (EVA) materials.

One surface of the double-sided tape <NUM> may be attached to the protective film <NUM>. Although not shown in the drawing, the double-sided tape <NUM> may be attached to the base film <NUM>. The planar heater <NUM> may have the double-sided tape <NUM> disposed on its one surface, and may thus be attached to a to-be-attached object by contacting the one surface on which the double-sided tape <NUM> is disposed to the to-be-attached object.

<FIG> is a flowchart showing a control method of a refrigerator according to another embodiment of the disclosure. Referring to <FIG>, a control method of a refrigerator <NUM> includes: measuring at least one of temperature and humidity outside the refrigerator <NUM> (S610); and driving at least one of first heating wires 120a arranged to surround an edge of a door and second heating wires 120b arranged on only one portion of the edge, based on a measured value (S620).

That is, a sensor measures at least one of the temperature and humidity outside the refrigerator <NUM>, and the processor determines whether to allow all or only one of the first heating wires 120a and the second heating wires 120b arranged at positions different from each other to be driven, depending on whether the measured value received from the sensor meets a predetermined condition.

In addition, the control method of the refrigerator <NUM> may further include determining an operating mode of the refrigerator based on the measured temperature and humidity, wherein in the driving of the heating wires (S620), only the first heating wires 120a may be driven in case that the determined operating mode is a normal mode, and the first heating wires 120a and the second heating wires 120b may be driven together in case that the determined operating mode is a high temperature and high humidity mode.

For example, in case that the environment outside the refrigerator <NUM> has high temperature and high humidity, the sensor may transmit information on the temperature and/or humidity outside the refrigerator to the processor, and the processor may determine the operating mode of the plurality of heating wires <NUM> as the high temperature and high humidity mode and allow the first heating wires 120a and the second heating wires 120b to be driven together.

Meanwhile, in case that the environment outside the refrigerator <NUM> has low temperature and low humidity, the sensor may transmit the information on the temperature and/or humidity outside the refrigerator to the processor, and the processor may determine the operating mode of the plurality of heating wires <NUM> as the normal mode and allow only the first heating wires 120a to be driven.

In addition, the control method of the refrigerator <NUM> further includes determining an operating duty of each of the first heating wires 120a and the second heating wires 120b based on a difference between temperatures inside and outside the refrigerator <NUM>, and the humidity outside the refrigerator <NUM>, wherein in the driving of the heating wires (S620), at least one of the first heating wires 120a and the second heating wires 120b are driven based on the operating duty of each of the first heating wires 120a and the second heating wires 120b.

That is, the processor may not simply determine on/off state of the plurality of heating wires <NUM>, but may determine the operating duty of each of the heating wires <NUM> and allow the plurality of heating wires <NUM> to be driven based on the determined operating duty.

Claim 1:
A refrigerator comprising:
a body (<NUM>) having a storage compartment (<NUM>);
a door (<NUM>) pivotally coupled to the body (<NUM>) to open and close the storage compartment, and having a door frame (<NUM>) including an upper frame (<NUM>) providing top edge of the door, a lower frame (<NUM>) providing a bottom edge of the door, a first side frame providing a first side edge of the door and a second side frame providing a second side edge of the door;
a planar heater (<NUM>) including:
a first heating wire (120a) extending along each of the upper frame, the lower frame, the first side frame and the second side frame, and
a second heating wire (120b) extending along at least one of the upper frame, the lower frame, the first side frame and the second side frame but not along each of the upper frame, the lower frame, the first side frame and the second side frame;
a sensor configured to measure at least one of temperature and humidity outside the refrigerator; and
a processor configured to control driving of at least one of the first heating wire and the second heating wire based on a measured value of the sensor, and
characterized by:
hinges (70c, 70d, 70e, 70f), on one of the first side frame and the second side frame, connecting the door (<NUM>) and the body (<NUM>) to each other,
wherein the second heating wire (120b) extends along the other of the first side frame and the second side frame.