Heating device and cooking appliance having same

Abstract

A heating device disclosed herein comprises: a power supply unit; a graphene heating layer configured to generate heat on the basis of a current from the power supply unit, and configured to transmit light; an electrode connected to the power supply unit, spaced apart from the graphene heating layer, and configured to receive the current from the power supply unit; and a conductive layer disposed on a base and electrically connecting the graphene heating layer and the electrode.

Description

Heating device and cooking appliance including same

[0001] The present disclosure relates to a heating device that generates heat using graphene and a cooking appliance including the same.

[0002] Graphene is a two-dimensional material composed of a single atomic layer, with carbon (C) atoms arranged in a two-dimensional lattice. A planar heating element made of graphene can be connected to an electrode, receive power, and generate heat.

[0003] Graphene possesses high electrical and thermal conductivity, as well as optical transparency, due to the arrangement of its carbon atoms. Furthermore, it exhibits the ability to bend under external impact or pressure, and its unique mesh structure (two-dimensional planar structure) allows it to be stronger than steel.

[0004] Due to the above characteristics, heating devices having graphene can be utilized in various technological and industrial fields in modern society.

[0005] One aspect of the present disclosure provides a heating device having a structure that maintains light transmittance and a cooking appliance including the same.

[0006] In addition, one aspect of the present disclosure provides a heating device including a structure capable of preventing a phenomenon of durability deterioration and a cooking appliance including the same.

[0007] In addition, one aspect of the present disclosure provides a heating device including a structure capable of preventing a short circuit phenomenon in an electrode or graphene even at high temperatures, and a cooking appliance including the same.

[0008] In addition, one aspect of the present disclosure provides a heating device including a structure capable of preventing structural instability due to thermal expansion mismatch between graphene and an electrode and current crowding phenomenon due to resistance difference, and a cooking appliance including the same.

[0009] Additional aspects will be partly explained in the ensuing description, partly will become apparent from the description, or may be learned by practicing the examples presented.

[0010] According to one aspect of the present disclosure, a heat generating device may include a power supply unit, a graphene heat generating layer configured to generate heat based on a current from the power supply unit and configured to be transparent to light, an electrode connected to the power supply unit and spaced apart from the graphene heat generating layer, the electrode configured to receive a current from the power supply unit, and a conductive layer disposed on a base and electrically connecting the graphene heat generating layer and the electrode.

[0011] The electrode may include a first electrode and a second electrode spaced apart from each other in the conductive layer. The graphene heating layer may be disposed between the first electrode and the second electrode and spaced apart from the first electrode and the second electrode.

[0012] The first electrode, the second electrode, and the graphene heating layer may each be in contact with the conductive layer. The conductive layer may be configured to allow light to transmit between the base and the graphene heating layer.

[0013] The resistance value of the conductive layer may be greater than the resistance value of the electrode and less than the resistance value of the graphene heating layer.

[0014] The first electrode, the second electrode, and the graphene heating layer may be disposed on the first surface of the conductive layer. The area of ​​the first surface of the conductive layer may be greater than the sum of the area of ​​the contact surface of the first electrode in contact with the first surface, the area of ​​the contact surface of the second electrode in contact with the first surface, and the area of ​​the contact surface of the graphene heating layer in contact with the first surface.

[0015] The contact surface of the conductive layer and the graphene heat-generating layer may extend from a first side of the graphene heat-generating layer adjacent to the first electrode to a second side of the graphene heat-generating layer adjacent to the second electrode.

[0016] The conductive layer may include a first conductive film arranged to be in contact with the base.

[0017] The conductive layer may further include a second conductive film disposed between the first conductive film and the graphene heating layer. A first side of the second conductive film may be in contact with the first conductive film, and a second side of the second conductive film may be in contact with the graphene heating layer and may be opposite to the first side.

[0018] The above second conductive film may include a titanium or nickel material.

[0019] The thickness of the second conductive film may be 5 nm or less.

[0020] The first side of the graphene heat-generating layer may be in contact with the conductive layer. The heat-generating device may further include an encapsulation layer covering a second side of the graphene heat-generating layer opposite to the first side. The encapsulation layer may include a metal oxide material.

[0021] The conductive layer may include a first conductive layer on which the first electrode is provided, and a second conductive layer spaced apart from the first conductive layer and on which the second electrode is provided.

[0022] The graphene heating layer may include a first region that is in contact with the first conductive layer and is spaced apart from the first electrode, a second region that is in contact with the second conductive layer and is spaced apart from the second electrode, and a third region that is positioned between the first region and the second region and is placed so as to be in contact with the base.

[0023] The first conductive layer may include a first conductive film in contact with the base, and a second conductive film disposed between the first conductive film and the graphene heat-generating layer. The second conductive layer may include a third conductive film in contact with the base, and a fourth conductive film disposed between the third conductive film and the graphene heat-generating layer.

[0024] The above graphene heating layer may be disposed on the conductive layer. The heating device may be configured to be light-transmittable.

[0025] The above graphene heating layer can be indirectly connected to the electrode through the conductive layer.

[0026] According to one aspect of the present disclosure, a heat generating device may include a power supply, an electrode connected to the power supply and configured to receive current from the power supply, the electrode including a first electrode and a second electrode spaced apart from the first electrode, a conductive layer electrically connected to the first electrode and the second electrode and including a first side in contact with a base, and a graphene heat generating layer in contact with the conductive layer between the first electrode and the second electrode, the graphene heat generating layer being configured to generate heat based on a current from the power supply and being configured to transmit light. The first electrode, the second electrode, and the graphene heat generating layer may be disposed on a second side of the conductive layer opposite the first side.

[0027] The conductive layer may be configured to allow light to pass between the base and the graphene heating layer.

[0028] The conductive layer may include a first conductive film including the first side in contact with the base and a second conductive film including the second side in contact with the first conductive film and opposite the first side.

[0029] The resistance value of the conductive layer may be greater than the resistance value of the electrode and less than the resistance value of the graphene heating layer.

[0030] A cooking appliance according to one aspect of the present disclosure may include a main body having a cooking chamber, a door rotatably coupled to the main body to open and close the cooking chamber, and a heating device installed on the door and configured to heat the cooking chamber. The heating device may include a power supply unit, a pair of electrodes each connected to the power supply unit to receive voltage from the power supply unit and spaced apart from each other, a graphene heating layer configured to receive power to generate heat, to allow light to pass through, and to be spaced apart from the pair of electrodes, and a conductive layer configured to allow current to flow and to conduct current between the pair of electrodes and the graphene heating layer, the conductive layer including one surface on which the pair of electrodes and the graphene heating layer are mounted, and the other surface being in contact with a base on which the heating device is installed and being an opposite surface of the one surface.

[0031] The above and other aspects, features and advantages of specific embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings.

[0032] Figure 1 is a conceptual diagram illustrating a heating device according to a comparative example.

[0033] FIG. 2 is a conceptual diagram illustrating a heating device according to one embodiment of the present disclosure.

[0034] FIG. 3 is a front view of FIG. 2 according to one embodiment of the present disclosure.

[0035] FIG. 4 is a conceptual diagram illustrating a heating device according to one embodiment of the present disclosure.

[0036] FIG. 5 is a conceptual diagram illustrating a heating device according to one embodiment of the present disclosure.

[0037] FIG. 6 is a conceptual diagram illustrating a heating device according to one embodiment of the present disclosure.

[0038] FIG. 7 is a front view of FIG. 6 according to one embodiment of the present disclosure.

[0039] FIG. 8 is a conceptual diagram illustrating a heating device according to one embodiment of the present disclosure.

[0040] FIG. 9 is a conceptual diagram illustrating a cooking appliance having a heating device installed therein according to various embodiments of the present disclosure.

[0041] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The embodiments described herein are merely exemplary embodiments, and the present disclosure is not limited thereto and may be implemented in various other forms.

[0042] The same reference numbers or symbols presented in each drawing of this specification represent parts or components that perform substantially the same function.

[0043] The terminology used herein is for the purpose of describing embodiments and is not intended to limit and / or restrict the disclosed invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this specification, the terms "comprises" or "has" and the like are intended to indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0044] Terms including ordinal numbers such as "first," "second," etc., used herein may be used to describe various components, but the components are not limited by the terms, and the terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. The term "and / or" includes any combination of a plurality of related listed items or any item among a plurality of related listed items.

[0045] Meanwhile, the shape and position of each component are not limited by the terms such as “front,” “back,” “left,” “right,” “upper,” and “lower” used in the description below.

[0046] When a component is said to be “connected,” “coupled,” “supported,” or “in contact with” another component, this includes not only cases where the components are directly connected, coupled, supported, or in contact, but also cases where the components are indirectly connected, coupled, supported, or in contact through a third component.

[0047] When we say that a component is "on" another component, this includes not only cases where the component is in contact with the other component, but also cases where there is another component between the two components.

[0048] When referring to the direction of rotation, clockwise may be referred to as the first direction, and counterclockwise, the direction opposite to the first direction, may be referred to as the second direction. While these expressions may be commonly used to describe specific details for implementing the invention, the rotational direction of the components of the present invention is not limited by these terms.

[0049] Hereinafter, a heating device and a cooking appliance including the same according to various embodiments will be specifically described with reference to the attached drawings.

[0050] Figure 1 is a conceptual diagram illustrating a heating device according to a comparative example.

[0051] Hereinafter, with reference to FIG. 1, a heat generating device (10') according to an embodiment compared to the heat generating device (10) according to the embodiment illustrated in FIGS. 2 to 9 will be described.

[0052] Referring to Door (D) Door (D) 1, the heating device (10') according to the comparative example can be provided to receive power and generate heat.

[0053] The heating device (10') may be configured to receive power from a power supply unit provided externally or internally and generate heat. The heating device (10') may be installed on a base (B). The base (B) may be a heating target heated by the heating device (10'). The base (B) may include various types of parts, devices, etc., on which the heating device (10') is installed and which may be heated by the heating device (10').

[0054] A heat generating device (10') according to a comparative example may include a power supply unit (110) configured to supply power, an electrode (140', including an electrode (140a') and an electrode (140b') configured to receive voltage from the power supply unit (110), a connection unit (120a, 120b) electrically connecting the power supply unit (110) and the electrode (140') to each other, and a graphene heat generating layer (130') configured to receive power and generate heat. For example, the graphene heat generating layer (130') may be arranged to be in contact with the base (B).

[0055] According to a comparative example, in order to supply power to the graphene heating layer (130'), the electrode (140') may be placed in direct contact with the graphene heating layer (130').

[0056] When the current moves from the electrode (140') to the graphene heating layer (130') in a state where the electrode (140') and the graphene heating layer (130') are in direct contact, such as in the heating device (10') according to the comparative example, a current crowding phenomenon may occur. The current crowding phenomenon means a phenomenon in which, when objects with different resistance values ​​are connected, the current prefers to proceed along a path with lower resistance, and thus the current is concentrated toward an object with a relatively lower resistance value.

[0057] For example, if there is a large difference in resistance between two objects in contact with each other, the current will be concentrated more toward the object with the lower resistance, which may aggravate the current concentration phenomenon.

[0058] For example, the electrode (140') may include a material having a line resistance of 0.1 ohm / m or less, and the graphene heating layer (130') may be provided with a surface resistance of 150 ohm / sq or more and 200 ohm / sq or less, so that a large resistance value difference may appear between the electrode (140') and the graphene heating layer (130') that are in contact with each other.

[0059] That is, when the electrode (140') and the graphene heating layer (130') are in direct contact, as in the structure of the heating device (10') according to the comparative example, a phenomenon may occur in which the current is concentrated on the electrode (140') having a relatively low resistance value because the difference in resistance value between the two components is large.

[0060] When current is concentrated on one of the objects in contact with each other, excessive heat may be generated in that object compared to the other objects. That is, in the heating device (10') according to the comparative example, excessive heat may be generated in the electrode (140') having a relatively low resistance value, which may cause damage to the electrode (140'). In addition, due to excessive heat generation in the electrode (140'), a thermal imbalance may occur at the contact surface (interface) between the electrode (140') and the graphene heating layer (130'), and through this, the contact force between the electrode (140') and the graphene heating layer (130') may be weakened, which may cause a decline in the overall durability of the heating device (10').

[0061] FIG. 2 is a conceptual diagram illustrating a heating device according to one embodiment of the present disclosure. FIG. 3 is a front view of FIG. 2. Descriptions of any content that overlaps with the above description will be omitted below.

[0062] Referring to FIGS. 2 and 3, the heating device (10) may be configured to receive power and generate heat.

[0063] The heat generating device (10) may be installed on the base (B). The base (B) may be a heat target to be heated by the heat generating device (10). The heat generating device (10) may be configured to heat the base (B). Even though the base (B) is a heat target of the heat generating device (10), the heat generating device (10) is not configured solely for the purpose of heating the base (B), and the heat generating device (10) may also be configured for the purpose of heating other components, devices, spaces, etc. other than the base (B). The expression "the base (B) is a heat target to be heated by the heat generating device (10)" described above may comprehensively refer to various examples of how the base (B) may be heated when the heat generating device (10) is supplied with power and generates heat. The base (B) may include various types of components, devices, etc. that may be heated by the heat generating device (10) when the heat generating device (10) is installed thereon.

[0064] The heating device (10) may include a power supply unit (110) configured to supply power, an electrode (140) configured to receive voltage from the power supply unit (110), a connection unit (120) electrically connecting the power supply unit (110) and the electrode (140) to each other, a graphene heating layer (130) configured to receive power and generate heat, and a conductive layer (150) configured to allow current to flow from the electrode (140) to the graphene heating layer (130) and laminated on a base (B) on which the heating device (10) is installed.

[0065] For example, the heating device (10) may be provided to be light-transmittable. The heating device (10) may be provided to be light-transmitting. The heating device (10) may include a light-transmitting material. The heating device (10) may be provided to be transparent.

[0066] For example, the graphene heat-generating layer (130) may be provided to be light-transmittable. For example, the conductive layer (150) may be provided to be light-transmittable. Light may transmit through the graphene heat-generating layer (130) and the conductive layer (150) in the order of the graphene heat-generating layer (130) and the conductive layer (150), or through the conductive layer (150) and the graphene heat-generating layer (130). This allows one side of the heat-generating device (10) to be easily recognized from the other side.

[0067] For example, the base (B) may be provided to allow light to pass through. Since the graphene heat-generating layer (130), the conductive layer (150), and the base (B) are each provided to allow light to pass through, light may pass through the graphene heat-generating layer (130), the conductive layer (150), and the base (B) in the order of the graphene heat-generating layer (130), the conductive layer (150), and the base (B), or in the order of the base (B), the conductive layer (150), and the graphene heat-generating layer (130).

[0068] The power supply unit (110) may include various devices that generate power or receive power from an external power source and transmit power to a required location.

[0069] For example, the power supply unit (110) may refer to a power supply unit for various devices, such as a cooking appliance (1) described later in FIG. 9, a battery that stores power, etc. The power supply unit (110) may itself include a separate battery. The power supply unit may be a device that independently generates and stores power.

[0070] In the city, the power supply unit (110) is depicted as a separate battery, but this is merely an example for explanation, and the power supply unit (110) may refer to various devices that generate power as described above or store and transmit power received from the outside.

[0071] The electrode (140) can be connected to the power supply (110) by the connection (120). The electrode (140) can be electrically connected to the power supply (110). For example, the electrode (140) can be connected to the power supply (110) so as to receive voltage from the power supply (110).

[0072] The electrode (140) may include a pair of electrodes (140a, 140b) spaced apart from each other by a specific distance (D3). The pair of electrodes (140) may be connected to a power supply unit (110) and may function as an anode (+, 140a) and a cathode (-, 140b), respectively. A space (S) may be formed between the pair of electrodes (140).

[0073] For example, a pair of electrodes (140a, 140b) may include a first electrode (140a) forming an anode and a second electrode (140b) forming a cathode.

[0074] For example, the first electrode (140a) may be connected to the power supply unit (110) through the first connection unit (120a) of the connection unit (120). For example, the second electrode (140b) may be connected to the power supply unit (110) through the second connection unit (120b) of the connection unit (120).

[0075] A pair of electrodes (140a, 140b) may be arranged to be spaced apart from each other on a conductive layer (150) laminated on a base (B). In other words, a pair of electrodes (140a, 140b) may be respectively mounted on the conductive layer (150). For example, a pair of electrodes (140a, 140b) may be arranged to be in contact with the conductive layer (150).

[0076] As will be described later, the conductive layer (150) may be a planar conductor through which current flows. Accordingly, the current generated by the electrode (140) receiving voltage from the power supply unit (110) can flow on the conductive layer (150) that causes a pair of electrodes (140a, 140b) to conduct current to each other. For example, the current may flow on an area of ​​the conductive layer (150) that is positioned between the pair of electrodes (140a, 140b). For example, the pair of electrodes (140a, 140b) may be positioned at each end of the conductive layer (150), but the positions of the pair of electrodes (140a, 140b) are not limited thereto.

[0077] The electrode (140) may include a material that is configured to receive voltage and allow current to flow. For example, the electrode (140) may include a material of Ag or Cu, but is not limited thereto. The electrode (140) may be formed by applying an electrode (140) paste containing Ag or Cu on a conductive layer (150), but is not limited thereto.

[0078] The graphene heating layer (130) may include a graphene layer having graphene material. The graphene layer is a polymer carbon isotrope in which carbon atoms are connected to each other in a hexagonal honeycomb shape to form a two-dimensional planar structure.

[0079] This shape can be called and referred to as a honeycomb structure or honeycomb lattice.

[0080] For example, the crystal structure of graphene material is an atomic structure (sp) with three bonds attached to each vertex. 2By means of (bonding), it can mean a form in which a hexagonal connection is extended in the plane direction. As a result, the crystal structure of the graphene material can have a two-dimensional crystal shape widely spread in the plane direction, which can form a hexagonal pore. Through this, the graphene material can exist as a thin film with a thickness of one atom, and due to the thin thickness, the absorption of visible light can be very low, so that it can exhibit light-transmitting characteristics. As a result, the graphene heating layer (130) including the graphene material can be provided transparently.

[0081] For example, a graphene layer may be formed as a single planar graphene structure, but may also include a structure in which multiple graphene materials are stacked.

[0082] For example, graphene can exhibit very high electron mobility and high thermal conductivity of approximately 5,000 W / mK. Furthermore, it possesses excellent electrical conductivity, and due to the structural characteristics of the two-dimensional honeycomb-like plane, it possesses high strength and excellent elasticity, so that it does not lose its electrical properties even when stretched or bent. Furthermore, defect-free graphene can exhibit heat resistance exceeding 1,000 degrees Celsius. Furthermore, as described above, when an anode and cathode are connected to both ends of graphene and current is passed through them, the graphene can be configured to generate heat.

[0083] For example, the graphene heat-generating layer (130) may be arranged to be stacked on the conductive layer (150). For example, the graphene heat-generating layer (130) may be arranged to be in contact with the conductive layer (150). For example, the graphene heat-generating layer (130) may be transferred to the conductive layer (150) and stacked on the conductive layer (150). For example, the graphene heat-generating layer (130) may be formed by directly transferring a graphene structure onto one surface of the conductive layer (150). The conductive layer (150) may function as a substrate for supporting the graphene heat-generating layer (130).

[0084] The graphene heat-generating layer (130) may be arranged to be spaced apart from a pair of electrodes (140a, 140b). In other words, the graphene heat-generating layer (130) may be arranged to be spaced apart from a pair of electrodes (140a, 140b) in a space formed by the pair of electrodes (140a, 140b) being spaced apart from each other. That is, the conductive layer (150) may be connected to the graphene heat-generating layer (130) and the electrode (140), respectively. A detailed description regarding the spaced arrangement between the pair of electrodes (140a, 140b) and the graphene heat-generating layer (130) will be described later.

[0085] As described above, when voltage is applied to the electrode (140) by the power supply unit (110), current can flow in the conductive layer (150) that conducts current between the pair of electrodes (140). Since the graphene heating layer (130) is arranged to be in contact with the conductive layer (150), current can be supplied to the graphene heating layer (130) through the conductive layer (150). Through this, the graphene heating layer (130) supplied with current can radiate heat in a direction toward the base (B).

[0086] For example, the base (B) may include, but is not limited to, a ceramic glass material, and may include various materials that are light-transmitting and highly heat-resistant.

[0087] When the heating device (10) is installed on the base (B), the conductive layer (150) may be laminated on the base (B). That is, the conductive layer (150) may be provided to be in direct contact with the base (B). For example, the expression of the base (B) may include a curved shape, and the conductive layer (150) may also be provided to be flexibly deformed to fit the curved shape. The conductive layer (150) may include a planar conductor. The conductive layer (150) may be formed as a single layer, but is not limited thereto.

[0088] For example, when the conductive layer (150) is a single layer, the conductive layer (150) may be formed to have a thickness (H1) of 10 nm or less. When the conductive layer (150) has a thickness (H1) of 10 nm or less, some of the visible light traveling toward the conductive layer (150) may not be absorbed by the conductive layer (150) due to the thickness (H1) of the thin conductive layer (150), and the unabsorbed visible light may transmit through the conductive layer (150). That is, the conductive layer (150) may be formed to be transparent due to its thin thickness.

[0089] Accordingly, when a conductive layer (150) is laminated on a base (B) having a light-transmitting characteristic, some of the visible light that has passed through the base (B) can also pass through the conductive layer (150), so that the user can observe an area beyond the base (B) and the conductive layer (150).

[0090] For example, the conductive layer (150) may include a material such as Pt or Au. Accordingly, current may flow on the conductive layer (150). In addition, the conductive layer (150) may include various materials with high electrical conductivity.

[0091] The above description of forming the conductive layer (150) as a single layer is merely an example, and the conductive layer (150) may be formed to include multiple layers. A detailed description thereof will be provided later.

[0092] Below, the structure in which the electrode (140) and the graphene heating layer (130) are spaced apart from each other is described in detail.

[0093] In various embodiments, the resistance values ​​of the electrode (140) and the graphene heating layer (130) may have a large difference.

[0094] For example, the electrode (140) may include a material of Ag-based paste and may contain glass frit to have high adhesion in relation to the above-described base (B). For example, the resistivity value of the electrode (140) is approximately 1.590 X 10-8 It may be Ωcm. For example, the electrode (140) may have a line resistance value of approximately 0.1 ohm / m or less.

[0095] For example, the resistivity of the graphene heating layer (130) is approximately 3.5Х10 -6 It may be Ωcm. For example, the graphene heating layer (130) may have a surface resistance value of approximately 150 ohm / sq or more and 200 ohm / sq or less.

[0096] Thus, according to one embodiment, the resistivity value of the graphene heating layer (130) (e.g., 3.5Х10 -6 Ωcm) is the resistivity value of the electrode (140) (e.g. 1.590Х10 -8 Ωcm), and if the electrode (140) and the graphene heating layer (130) come into contact with each other, the difference in the resistivity value may induce a current crowding phenomenon. This current crowding phenomenon may also reduce the durability of the heating device (10). In one embodiment of the present disclosure, the current crowding phenomenon as described above can be prevented by separating the electrode (140) and the graphene heating layer (130) from each other (see FIG. 4).

[0097] In one embodiment of the present disclosure, the electrode (140) and the graphene heat-generating layer (130) may be electrically connected by being connected to a conductive layer (150) having a higher resistance value than the electrode (140) and a lower resistance value than the graphene heat-generating layer (130) instead of being spaced apart from each other. According to one embodiment, the resistance values ​​of the electrode (140), the conductive layer (150), and the graphene heat-generating layer (130) may increase in the order of the electrode (140), the conductive layer (150), and the graphene heat-generating layer (130).

[0098] For example, the resistivity value of the conductive layer (150) is approximately 10.6Х10 -8 It may be Ωcm. For example, the surface resistance value of the conductive layer (150) may be approximately 150 ohm / sq or more and 200 ohm / sq or less.

[0099] Thus, according to one embodiment, when the electrode (140) and the graphene heating layer (130) are directly connected, the difference in resistivity between the two configurations is approximately 3.484Х10 -6 Ωcm, and when the electrode (140) and the graphene heating layer (130) are indirectly connected by the conductive layer (150), the difference in resistivity between the electrode (140) and the conductive layer (150) is approximately 9.01Х10 -8 Ωcm and the difference in resistivity between the graphene heating layer (130) and the conducting layer (150) is approximately 3.394Х10 -6 It can be Ωcm. From this, it can be seen that the difference in resistivity between the electrode (140) and the conductive layer (150) and the difference in resistivity between the graphene heat-generating layer (130) and the conductive layer (150) are smaller than the difference in resistivity between the electrode (140) and the graphene heat-generating layer (130). That is, compared to the embodiment in which the electrode (140) and the graphene heat-generating layer (130) are directly connected to each other, in the embodiment in which the electrode (140) and the graphene heat-generating layer (130) are indirectly connected by the conductive layer (150), the change in resistance at the contact surface between the components can be more alleviated, thereby preventing the current crowding phenomenon and improving the durability of the heat-generating device (10).

[0100] In the above, the resistivity value of the electrode (140) is approximately 1.590Х10 -8 Ωcm and the line resistance value is approximately 0.1 ohm / m or less, the resistivity value of the graphene heating layer (130) is approximately 3.5Х10 -6 Ωcm and the surface resistance value is approximately 150 ohm / sq or more and 200 ohm / sq or less, the resistivity value of the conductive layer (150) is approximately 10.6Х10 -8Although the case where the resistance is Ωcm and the surface resistance is approximately 35 ohm / sq or more and 40 ohm / sq or less has been described as an example, this is only an example, and in various embodiments, the resistance values ​​of the electrode (140), the graphene heating layer (130), and the conductive layer (150) can be variously provided within a range where the resistance value of the electrode (140) is the smallest, the resistance value of the graphene heating layer (130) is the largest, and the resistance value of the conductive layer (150) has a value between the resistance value of the electrode (140) and the resistance value of the graphene heating layer (130).

[0101] In the case where the electrode (140) and the graphene heating layer (130) are arranged to be spaced apart as described above and the electrical connection between them is replaced by the conductive layer (150), the path through which the current flows can be designed in the order of electrode (140) - conductive layer (150) - graphene heating layer (130), so that the difference in the formed resistance value can be changed more gradually, and the current crowding phenomenon can be effectively prevented compared to the case where the resistance value changes abruptly.

[0102] For example, the first electrode (140) and the graphene heat-generating layer (130) may be spaced apart from each other by a first distance (D1). In other words, the first electrode (140) and the graphene heat-generating layer (130) may be positioned so as to form a first space (S1) therebetween. The first electrode (140) and the graphene heat-generating layer (130) may each be positioned so as to be in contact with the conductive layer (150). Through this, the first electrode (140) and the graphene heat-generating layer (130) may not directly contact each other, but may be electrically conductive.

[0103] For example, the second electrode (140) and the graphene heat-generating layer (130) may be spaced apart from each other by a second distance (D2). In other words, the second electrode (140) and the graphene heat-generating layer (130) may be positioned so as to form a second space (S2) therebetween. The second electrode (140) and the graphene heat-generating layer (130) may each be positioned so as to be in contact with the conductive layer (150). Through this, the second electrode (140) and the graphene heat-generating layer (130) may not be in direct contact with each other, but may be electrically conductive.

[0104] For example, the first distance (D1) and the second distance (D2) may be arranged to correspond to each other, but this is not limited to the first distance (D1) and the second distance (D2) may be arranged in various ways to suit the usage environment and characteristics.

[0105] The graphene heating layer (130) can be placed in a third space (S3) between the first space (S1) and the second space (S2), and can extend along the third space (S3).

[0106] The first electrode (140), the graphene heating layer (130), and the second electrode (140) are spaced apart from each other and do not directly contact each other, but can be electrically connected to each other by the conductive layer (150). Therefore, the first electrode (140), the graphene heating layer (130), and the second electrode (140) can be electrically connected to each other while preventing current crowding.

[0107] For example, the thickness (H1) of the conductive layer (150) can be provided in various ways. For example, the thickness (H1) of the conductive layer (150) can have a thickness of 5 nm or more and less than 10 nm, but is not limited thereto.

[0108] In the case of the conductive layer (150), when the thickness (H1) increases, the resistance value of the conductive layer (150) may decrease, and when the thickness (H1) decreases, the resistance value may increase. Depending on the type of electrode (140), an electrode (140) having various resistance values ​​may be applied to the heating device (10), and the resistance value of the conductive layer (150) may be positioned between the resistance value of the electrode (140) and the resistance value of the graphene heating layer (130) by adjusting the thickness (H1). Therefore, the above-described current crowding phenomenon can be effectively prevented.

[0109] In a comparative example, when heat is generated in the graphene heat-generating layer (130'), a force may be applied to the contact area between the electrode (140') and the graphene heat-generating layer (130') due to the difference in thermal expansion coefficient between the electrode (140') and the graphene heat-generating layer (130'). For example, the electrode (140) and the graphene heat-generating layer (130) have different thermal expansion coefficients. When heat is applied, the electrode (140) may expand, but the graphene heat-generating layer (130) may contract, on the contrary. For example, when the electrode (140) includes a material of Ag-based paste, the thermal expansion coefficient of the electrode (140) is 19.5 * 10 -6 (K -1 ) can be prepared, and the thermal expansion coefficient of the graphene heating layer (130) is -8.0 * 10 -6 (K -1 ) can be provided, but is not limited thereto.

[0110] In a comparative example, since the electrode (140') and the graphene heating layer (130') are deformed to contract / expand in different directions, a horizontal shear force may occur at the contact surface of the electrode (140') and the graphene heating layer (130'), which may cause the contact between the electrode (140') and the graphene heating layer (130') to be separated, which may cause a decrease in the durability of the heating device (10').

[0111] As described above, when a shear force occurs at the interface between the graphene heating layer (130') and the electrode (140'), migration of metal atoms may occur, which may further reduce the durability of the heating device (10'). In addition, a short circuit phenomenon may even occur at the interface between the electrode (140') and the graphene heating layer (130').

[0112] According to one embodiment of the present disclosure, when the electrode (140) and the graphene heating layer (130) are spaced apart from each other, the occurrence of shear force and migration due to the difference in thermal expansion as described above can be suppressed, thereby preventing a decrease in the durability of the heating device (10).

[0113] Referring to FIGS. 2 and 3, a conductive layer (150) can connect a pair of electrodes (140a, 140b). The conductive layer (150) can be connected to each of the first electrode (140a) and the second electrode (140b). The conductive layer (150) can extend from the first electrode (140a) to the second electrode (140b). A contact surface between the conductive layer (150) and the graphene heating layer (130) can extend from one side of the graphene heating layer (130) adjacent to one of the pair of electrodes (140a, 140b) (e.g., the first electrode (140a)) to the other side of the graphene heating layer (130) adjacent to the other of the pair of electrodes (140a, 140b) (e.g., the second electrode (140b)). In other words, the conductive layer (150) can almost entirely contact one surface of the graphene heating layer (130).

[0114] As the conductive layer (150) is in contact with almost the entire surface of the graphene heat-generating layer (130) in this way, the uniformity of voltage applied to the graphene heat-generating layer (130) can increase, and the degree of heat generation in almost the entire region of the graphene heat-generating layer (130) can become more uniform. In addition, the phenomenon of current concentration in a specific region of the graphene heat-generating layer (130) can be further reduced and / or prevented.

[0115] Figure 4 is a conceptual diagram illustrating a heating device according to one embodiment of the present disclosure. Descriptions of any content that overlaps with the above description will be omitted below.

[0116] Referring to FIG. 4, the conductive layer (250) may include a first conductive film (252) arranged to be in contact with the base (B).

[0117] The conductive layer (250) may include a second conductive film (251) disposed between the first conductive film (252) and the graphene heating layer (230).

[0118] For example, the first conductive film (252) may include a material such as Pt or Au. Accordingly, current may flow on the first conductive film (252). For example, the thickness (H2) of the first conductive film (252) may be formed to be approximately 10 nm or less. For example, the first conductive film (252) may include a planar conductor.

[0119] The second conductive film (251) may include a first side (2521) that is in contact with the first conductive film (252), and a second side (2522) that is in contact with the graphene heating layer (230) and is the opposite side of the first side (2521). That is, the graphene heating layer (230) may be laminated on the conductive layer (250) so as to be in contact with the second conductive film (251).

[0120] A pair of electrodes (240a, 240b) may be respectively disposed on a second conductive film (251). A pair of electrodes (240a, 240b) may be respectively disposed to be in contact with a second conductive film (251). A pair of electrodes (240a, 240b) and a graphene heating layer (230) may be respectively disposed to be spaced apart from each other on the second conductive film (251).

[0121] For example, the second conductive film (251) may include a material through which current flows. For example, the thickness (H3) of the second conductive film (251) may be set to 5 nm or less. For example, the second conductive film (251) may include a planar conductor.

[0122] Through the above-described arrangement and the characteristics of the second conductive film (251), current can flow between a pair of electrodes (240a, 240b) and the graphene heating layer (230). The pair of electrodes and the graphene heating layer (230) can be mutually conductive by the second conductive film (251) and the first conductive film (252).

[0123] For example, the second conductive film (251) may include a material such as titanium (Ti) or nickel (Ni). As the second conductive film (251) including the above-described material is placed between the graphene heat-generating layer (230) and the first conductive film (252), the shear force that may occur at the contact surface between the graphene heat-generating layer (230) and the first conductive film (252) due to the difference in thermal conductivity between the two can be further reduced.

[0124] In addition, as the graphene heating layer (230) and the first conductive film (252) are in direct contact, there is a difference in surface energy due to a difference in materials between the graphene heating layer (230) and the first conductive film (252), and thus, a dewetting or differentiation phenomenon may occur at the contact surface between the graphene heating layer (230) and the first conductive film (252).

[0125] When dewetting or differentiation occurs, the contact force at the contact surface between the graphene heating layer (230) and the first conductive film (252) becomes weak, which may cause the graphene heating layer (230) to be lifted. However, this phenomenon can be prevented by placing a second conductive film (251) containing a Ti or Ni material between the graphene heating layer (230) and the first conductive film (252).

[0126] Referring to FIG. 4, a conductive layer (250) can connect a pair of electrodes (240a, 240b). The conductive layer (250) can be connected to each of the first electrode (240a) and the second electrode (240b). The conductive layer (250) can extend from the first electrode (240a) to the second electrode (240b). A contact surface (e.g., the second surface (2522)) between the conductive layer (250) and the graphene heating layer (230) can extend from one side of the graphene heating layer (230) adjacent to one electrode (e.g., the first electrode (240a)) of the pair of electrodes (240a, 240b) to the other side of the graphene heating layer (230) adjacent to the other electrode (e.g., the second electrode (240b)) of the pair of electrodes (240a, 240b). In other words, the conductive layer (250) can almost entirely contact one surface of the graphene heating layer (230).

[0127] As the conductive layer (250) is in contact with almost the entire surface of the graphene heat-generating layer (230) in this way, the uniformity of voltage applied to the graphene heat-generating layer (230) can increase, and the degree of heat generation in almost the entire region of the graphene heat-generating layer (230) can become more uniform. In addition, the phenomenon of current concentration in a specific region of the graphene heat-generating layer (230) can be further reduced and / or prevented.

[0128] FIG. 5 is a conceptual diagram illustrating a heating device according to one embodiment of the present disclosure. Descriptions of any content that overlaps with the above description will be omitted below.

[0129] Referring to FIG. 5, the heating device (20) may include an encapsulation layer (360) covering a graphene heating layer (330). The encapsulation layer (360) may cover a surface different from the surface of the graphene heating layer (330) that contacts the conductive layer (350). The encapsulation layer (360) may surround the graphene heating layer (330) so that the graphene heating layer (330) is not exposed to air.

[0130] The encapsulation layer (360) may include a metal oxide material. The encapsulation layer (360) may include various types of metal oxides of the oxide series. As a result, the encapsulation layer (360) can prevent the graphene heat-generating layer (330) from being oxidized when exposed to air. The graphene heat-generating layer (330) generates heat at a high temperature when voltage is applied and may be vulnerable to oxidation when exposed to air. However, since the encapsulation layer (360) including the metal oxide material surrounds the graphene heat-generating layer (330), the oxidation of the graphene heat-generating layer (330) can be effectively prevented. Therefore, the durability of the graphene heat-generating layer (330) and the overall durability of the heat-generating device (20) can be improved.

[0131] The encapsulation layer (360) can be formed to a thickness sufficiently thin to allow light to pass through.

[0132] Referring to FIG. 5, a conductive layer (350) can connect a pair of electrodes (340a, 340b). The conductive layer (350) can be connected to each of the first electrode (340a) and the second electrode (340b). The conductive layer (350) can extend from the first electrode (340a) to the second electrode (340b). A contact surface between the conductive layer (350) and the graphene heating layer (330) can extend from one side of the graphene heating layer (330) adjacent to one of the pair of electrodes (340a, 340b) (e.g., the first electrode (340a)) to the other side of the graphene heating layer (330) adjacent to the other of the pair of electrodes (340a, 340b) (e.g., the second electrode (340b)). In other words, the conductive layer (350) can almost entirely contact one surface of the graphene heating layer (330).

[0133] As the conductive layer (350) is in contact with almost the entire surface of the graphene heat-generating layer (330) in this way, the uniformity of voltage applied to the graphene heat-generating layer (330) can increase, and the degree of heat generation in almost the entire region of the graphene heat-generating layer (330) can become more uniform. In addition, the phenomenon of current concentration in a specific region of the graphene heat-generating layer (330) can be further reduced and / or prevented.

[0134] FIG. 6 is a conceptual diagram illustrating a heating device according to one embodiment of the present disclosure. FIG. 7 is a front view of FIG. 6. Descriptions of any content overlapping with the above will be omitted below.

[0135] Referring to FIGS. 6 and 7, the conductive layer (450) may include a first conductive layer (450a) on which a first electrode (440a) is mounted, and a second conductive layer (450b) on which a second electrode (440b) is mounted and spaced apart from the first conductive layer (450a). For example, the first conductive layer (450a) and the second conductive layer (450b) may each include a material such as Pt or Au, but are not limited thereto.

[0136] The graphene heat-generating layer (430) may be arranged so that one side of the graphene heat-generating layer (430) is in contact with the first conductive layer (450a). The one side of the graphene heat-generating layer (430) in contact with the first conductive layer (450a) may be referred to as a first region (431). That is, the graphene heat-generating layer (430) may include the first region (431).

[0137] For example, the first region (431) may refer to one end of the graphene heating layer (430) in the horizontal direction. For example, the first region (431) may be arranged to be in contact with the first conductive layer (450a).

[0138] The first region (431) can be positioned to be spaced apart from the first electrode (440a).

[0139] The graphene heat-generating layer (430) may be arranged so that the other side of the graphene heat-generating layer (430) is in contact with the second conductive layer (450b). The other side of the graphene heat-generating layer (430) in contact with the second conductive layer (450b) may be referred to as a second region (432). That is, the graphene heat-generating layer (430) may include the second region (432).

[0140] For example, the second region (432) may refer to the other end of the graphene heating layer (430) in the horizontal direction. For example, the second region (432) may be arranged to be in contact with the second conductive layer (450b). The second region (432) may be arranged to be spaced apart from the second electrode (440b).

[0141] Another part of the graphene heating layer (430) located between the first region (431) and the second region (432) may be referred to as a third region (433).

[0142] Since the graphene heating layer (430) is provided flexibly, the third region (433) can move by gravity and be positioned lower than the first region (431) and the second region (432).

[0143] For example, the third region (433) can be in contact with the base. For example, the third region (433) can be located in a space formed by the first conductive layer (450a) and the second conductive layer (450b) being spaced apart from each other. The third region (433) can extend from the space formed by the first conductive layer (450a) and the second conductive layer (450b) being spaced apart from each other and come into contact with the base.

[0144] Current can flow in the conductive layer (450) and the graphene heating layer (430). In addition, since the first electrode (440a) is electrically connected to the graphene heating layer (430) by the first conductive layer (450a), and the second electrode (440b) is electrically connected to the graphene heating layer (430) by the second conductive layer (450b), current can flow through the first electrode (440a), the graphene heating layer (430), and the second electrode (440b).

[0145] Since the conductive layer (450) is formed as a first conductive layer (450a) and a second conductive layer (450b) that are spaced apart from each other and do not extend over the base (B) so as to correspond to the width of the heating device, the manufacturing cost of the conductive layer (450) can be reduced.

[0146] Figure 8 is a conceptual diagram illustrating a heating device according to one embodiment of the present disclosure. Descriptions of any content overlapping with the above will be omitted below.

[0147] Referring to FIG. 8, the first conductive layer (550a) may include a first conductive film (552a) in contact with the base (B) and a second conductive film (551a) disposed between the first conductive film (552a) and the graphene heating layer (530).

[0148] In addition, the second conductive layer (550b) may include a third conductive film (552b) in contact with the base (B) and a fourth conductive film (551b) disposed between the third conductive film (552b) and the graphene heating layer (530).

[0149] The first conductive film (552a) and the third conductive film (552b) may each include a Pt or Au material, but are not limited thereto. The second conductive film (551a) and the fourth conductive film (551b) may each include a Ti or Ni material, but are not limited thereto.

[0150] The graphene heat-generating layer (530) may be arranged such that one side of the graphene heat-generating layer (530) is in contact with the second conductive film (551a). The one side of the graphene heat-generating layer (530) in contact with the second conductive film (551a) may be referred to as a first region (531). That is, the graphene heat-generating layer (530) may include the first region (531).

[0151] For example, the first region (531) may refer to one end of the graphene heating layer (530) in the horizontal direction. For example, the first region (531) may be arranged to be in contact with the first conductive layer (550a). The first region (531) may be arranged to be spaced apart from the first electrode (540a).

[0152] The graphene heat-generating layer (530) may be arranged so that the other side of the graphene heat-generating layer (530) is in contact with the fourth conductive film (551b). The other side of the graphene heat-generating layer (530) in contact with the fourth conductive film (551b) may be referred to as a second region (532). That is, the graphene heat-generating layer (530) may include the second region (532). For example, the second region (532) may mean the other end of the graphene heat-generating layer (530) in the horizontal direction. For example, the second region (532) may be arranged so as to be in contact with the fourth conductive film (551b). The second region (532) may be arranged so as to be spaced apart from the second electrode (540b).

[0153] Another part of the graphene heating layer (530) located between the first region (531) and the second region (532) may be referred to as a third region (533). Since the graphene heating layer (530) is provided flexibly, the third region (533) may move by gravity and be located lower than the first region (531) and the second region (532). For example, the third region (533) may be in contact with the base (B).

[0154] For example, the third region (533) may be located in a space formed by the first conductive layer (550a) and the second conductive layer (550b) being spaced apart from each other.

[0155] FIG. 9 is a conceptual diagram illustrating a cooking appliance having a heating device installed therein according to various embodiments of the present disclosure.

[0156] Referring to FIG. 9, a heating device (10) according to various embodiments of the present disclosure may be installed in a cooking appliance (1). The cooking appliance (1) may include a heating device (10). Hereinafter, the heating device (10) included in the cooking appliance (1) is described as the heating device (10) of FIGS. 2 and 3 as an example, but the cooking appliance (1) may include heating devices (10, 20, 30, 40, 50) of the embodiments described with reference to FIGS. 2 to 8.

[0157] According to various embodiments, the cooking appliance (1) may include a main body (C) that forms an exterior and forms a cooking chamber (R) in which food contained in a cooking container (F) is cooked. The cooking appliance (1) may include a door (D) that is rotatably coupled to the main body (C) to open and close the cooking chamber (R). The door (D) may include a window (B) that is provided to allow light to pass through so that the interior of the cooking chamber (R) can be viewed from the outside.

[0158] For example, the window (B) may include a light-transmitting glass material. For example, the window (B) may include a ceramic glass material. However, the material of the window (B) is not limited thereto, and in various embodiments, the window (B) may include various materials that are light-transmitting and have high heat resistance.

[0159] The heating device (10) may be installed inside the cooking appliance (1). The heating device (10) may be installed inside the cooking appliance (1) to heat the cooking chamber (R). For example, the heating device (10) may be installed in the door (D). The heating device (10) may be installed on one side of the door (D) facing the inside of the cooking chamber (R). The heating device (10) may be installed on one side of the window (B) facing the inside of the cooking chamber (R).

[0160] However, the location of the heating device (10) is not limited thereto, and the heating device (10) may be installed in various locations of the cooking appliance (1) so as to heat the cooking chamber (R). For example, the heating device (10) may be installed in various locations so as to heat the cooking chamber (R), such as being arranged across the cooking chamber (R) on the upper side of the cooking chamber (R), or being arranged on one side of the rear inner surface of the main body (C) facing the door (D).

[0161] In the following description, it is assumed that the heating device (10) is installed on one side of the inner surface of the window (B) facing the cooking chamber (R). That is, the window (B) may be a heating target and a base (B) on which the heating device (10) is installed.

[0162] As described above, the window (B) and the heating device (10) may each be provided to allow light to pass through. The window (B), the conductive layer (150), and the graphene heating layer (130) may each be provided to allow light to pass through.

[0163] Accordingly, the window (B), the graphene heating layer (130), and the conductive layer (150) can be configured so that light from outside the cooking device (1) is transmitted and incident into the cooking chamber (R), or light from inside the cooking chamber (R) is transmitted and emitted to the outside of the cooking device (1). For example, light from outside the cooking device (1) can sequentially transmit through the window (B), the conductive layer (150), and the graphene heating layer (130) and incident into the cooking chamber (R). Light from inside the cooking chamber (R) can sequentially transmit through the graphene heating layer (130), the conductive layer (150), and the window (B) and emitted to the outside of the cooking device (1).

[0164] In this way, the user can observe the inside of the cooking chamber (R) through the window (B) and the heating device (10) from the outside of the cooking appliance (1), thereby ensuring visibility of the cooking chamber (R), and easily observing the cooking status of the food in the cooking container (F) inside the cooking chamber (R).

[0165] In various embodiments, the heating device (10) can be installed and applied to various parts, devices, etc. that require heating in addition to the cooking appliance (1).

[0166] A heat generating device (10) according to one embodiment of the present disclosure may include a power supply unit (110), a graphene heat generating layer (130) configured to receive power to generate heat and to allow light to pass through, an electrode (140) connected to the power supply unit (110) to receive voltage from the power supply unit (110) and arranged to be spaced apart from the graphene heat generating layer (130), and a conductive layer (150) laminated on a base (B) that is a heating target, configured to allow current to flow, and connected to the graphene heat generating layer (130) and the electrode (140) respectively to conduct current between the graphene heat generating layer (130) and the electrode (140).

[0167] The electrode (140) may include a pair of electrodes (140a, 140b) spaced apart from each other and mounted on the conductive layer (150). The graphene heating layer (130) may be spaced apart from the pair of electrodes (140a, 140b) in a space formed by the pair of electrodes (140a, 140b) spaced apart from each other.

[0168] The above pair of electrodes (140a, 140b) and the graphene heating layer (130) may be arranged to be in contact with the conductive layer (150), respectively. The conductive layer (150) may be provided to allow light to pass through.

[0169] The resistance value of the conductive layer (150) may be set to be greater than the resistance value of the electrode (140) and less than the resistance value of the graphene heating layer (130).

[0170] The pair of electrodes (140a, 140b) and the graphene heating layer (130) may be respectively mounted on one surface of the conductive layer (150). The cross-sectional area of ​​the one surface of the conductive layer (150) may be set to be wider than the sum of the cross-sectional areas of the contact surfaces of each of the pair of electrodes (140a, 140b) in contact with the one surface and the cross-sectional area of ​​the contact surface of the graphene heating layer (130) in contact with the one surface.

[0171] The contact surface of the conductive layer (150) and the graphene heat-generating layer (130) may extend from one side of the graphene heat-generating layer (130) adjacent to one of the pair of electrodes (140a, 140b) to the other side of the graphene heat-generating layer (130) adjacent to the other of the pair of electrodes (140a, 140b).

[0172] The above conductive layer (250) may include a first conductive film (252) arranged to be in contact with the base (B).

[0173] The thickness of the above first conductive film (252) can be set to 10 nm or less.

[0174] The conductive layer (250) may further include a second conductive film (251) disposed between the first conductive film (252) and the graphene heating layer (230), and including a first surface (2521) in contact with the first conductive film (252), and a second surface (2522) in contact with the graphene heating layer (230) and being the opposite surface of the first surface (2521).

[0175] The above second conductive film (251) may include a Ti or Ni material.

[0176] The thickness of the above second conductive film (241) can be set to 5 nm or less.

[0177] The above-described heating device (20) may further include an encapsulation layer (360) that covers a surface different from the surface of the graphene heating layer (330) that contacts the conductive layer (350). The encapsulation layer (360) may include an oxide metal material.

[0178] The above pair of electrodes (440a, 440b) may include a first electrode (440a) and a second electrode (440b) spaced apart from the first electrode (440a). The conductive layer (450) may include a first conductive layer (450a) on which the first electrode (440a) is mounted, and a second conductive layer (450b) spaced apart from the first conductive layer (450a) and on which the second electrode (440b) is mounted.

[0179] The graphene heating layer (430) may include a first region (431) that is in contact with the first conductive layer (450a) and spaced apart from the first electrode (440a), a second region (432) that is in contact with the second conductive layer (450b) and spaced apart from the second electrode (440b), and a third region (433) that is positioned between the first region (431) and the second region (432) and is in contact with the base (B).

[0180] The first conductive layer (550a) may include a first conductive film (552a) in contact with the base (B) and a second conductive film (551a) disposed between the first conductive film (552a) and the graphene heating layer (530). The second conductive layer (550b) may include a third conductive film (552b) in contact with the base (B) and a fourth conductive film (551b) disposed between the third conductive film (552b) and the graphene heating layer (530).

[0181] The above graphene heating layer (130) can be transferred to the conductive layer (150) and laminated on the conductive layer (150), and the heating device (10) can be provided to be optically transparent.

[0182] A cooking appliance (1) according to one embodiment of the present disclosure may include a main body (C) having a cooking chamber (R), a door (D) rotatably coupled to the main body (C) to open and close the cooking chamber (R), and a heating device (10) installed in the door (D) and configured to heat the cooking chamber (R). The above heat generating device (10) comprises a power supply unit (110), a pair of electrodes (140a, 140b) that are respectively connected to the power supply unit (110) and spaced apart from each other so as to receive voltage from the power supply unit (110), a graphene heat generating layer (130) that is arranged to receive power to generate heat, is arranged to allow light to pass through, and is spaced apart from the pair of electrodes (140a, 140b), and a conductive layer (150) that is arranged to allow current to flow and conduct electricity between the pair of electrodes (140a, 140b) and the graphene heat generating layer (130), and includes one surface on which the pair of electrodes (140a, 140b) and the graphene heat generating layer (130) are mounted, and the other surface that is in contact with the base (B) on which the heat generating device (10) is installed and is the opposite surface of the one surface. It may include a conductive layer (150).

[0183] The above graphene heating layer (130) can be arranged so as to be spaced apart from the pair of electrodes (140a, 140b) in a space (S1, S2) formed by the pair of electrodes (140a, 140b) being spaced apart from each other.

[0184] The above pair of electrodes (140a, 140b) and the graphene heating layer (130) may be respectively mounted on one surface of the conductive layer (150). The cross-sectional area of ​​one surface of the conductive layer (150) may be set to be wider than the sum of the cross-sectional areas of the contact surfaces of each of the pair of electrodes (140a, 140b) in contact with the one surface and the cross-sectional area of ​​the contact surface of the graphene heating layer (130) in contact with the other surface.

[0185] The above pair of electrodes (140a, 140b) and the graphene heating layer (130) can be arranged to be in contact with the conductive layer (150), respectively.

[0186] The above pair of electrodes (440a, 440b) may include a first electrode (440a) and a second electrode (440b) spaced apart from the first electrode (440a). The conductive layer (450) may include a first conductive layer (450a) on which the first electrode (440a) is mounted, and a second conductive layer (450b) spaced apart from the first conductive layer (450a) and on which the second electrode (440b) is mounted.

[0187] The above door (D) may include a window (B) that is provided to allow light to pass through. The conductive layer (150) may be provided to allow light to pass through. The window (B), the graphene heating layer (130), and the conductive layer (150) may be configured such that light from outside the cooking device (1) is transmitted through and incident into the cooking chamber (R), or light from inside the cooking chamber (R) is transmitted through and emitted to the outside of the cooking device (1).

[0188] According to the invention of the present disclosure, since the conductive layer and the graphene heating layer can maintain light transparency, a heating device that does not impair user visibility can be provided.

[0189] According to the idea of ​​the present disclosure, the electrodes and the graphene heating layer are arranged to be spaced apart from each other and are arranged to be in contact with the conductive layer, so that the current moves from the electrodes through the conductive layer to the graphene heating layer, thereby preventing the current crowding phenomenon caused by a sharp resistance difference and improving durability.

[0190] According to the invention of the present invention, since the electrode and the graphene heating layer do not come into direct contact with each other, a short circuit phenomenon of the heating device caused by a difference in thermal expansion coefficient between the two at high temperatures can be prevented.

[0191] According to the idea of ​​the present disclosure, the conductive layer may include a Ti material and have a second conductive film in contact with the graphene heating device, so that the stress applied to the graphene heating layer can be further reduced compared to when the graphene heating layer is in contact with the first conductive film.

[0192] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure belongs from the description below.

[0193] The above-described embodiments are merely specific examples intended to illustrate the technical content of embodiments of the present disclosure and aid in understanding of the embodiments of the present disclosure, and are not intended to limit the scope of the embodiments of the present disclosure. Therefore, the scope of the various embodiments of the present disclosure should be interpreted to include all modifications or variations derived based on the technical concepts of the various embodiments of the present disclosure, in addition to the embodiments disclosed herein.

Claims

1. Power supply unit; A graphene heating layer configured to generate heat based on current from the power supply unit and configured to be light-transmittable; An electrode connected to the power supply and spaced apart from the graphene heating layer, the electrode configured to receive current from the power supply; and A heating device comprising a conductive layer disposed on a base and electrically connecting the graphene heating layer and the electrode.

2. In paragraph 1, The electrode includes a first electrode and a second electrode spaced apart from each other in the conductive layer, A heating device in which the graphene heating layer is disposed between the first electrode and the second electrode and is spaced apart from the first electrode and the second electrode.

3. In paragraph 2, The first electrode, the second electrode, and the graphene heating layer are in contact with the conductive layer, respectively, A heating device in which the conductive layer is configured to allow light to pass between the base and the graphene heating layer.

4. In paragraph 1, A heating device in which the resistance value of the conductive layer is greater than the resistance value of the electrode and less than the resistance value of the graphene heating layer.

5. In paragraph 2, The first electrode, the second electrode, and the graphene heating layer are arranged on the first surface of the conductive layer, A heating device in which the area of ​​the first surface of the conductive layer is greater than the sum of the area of ​​the contact surface of the first electrode in contact with the first surface, the area of ​​the contact surface of the second electrode in contact with the first surface, and the area of ​​the contact surface of the graphene heating layer in contact with the first surface.

6. In paragraph 2 The contact surface of the above conductive layer and the above graphene heating layer is, A heating device extending from a first side of the graphene heating layer adjacent to the first electrode to a second side of the graphene heating layer adjacent to the second electrode.

7. In paragraph 1 A heating device comprising a first conductive film arranged so as to be in contact with the base, wherein the conductive layer is 8. In paragraph 7, The conductive layer further includes a second conductive film disposed between the first conductive film and the graphene heating layer, A heating device in which a first side of the second conductive film is in contact with the first conductive film, and a second side of the second conductive film is in contact with the graphene heating layer and is opposite to the first side.

9. In paragraph 8, The above second conductive film is a heating device including a titanium or nickel material.

10. In paragraph 8, A heating device wherein the thickness of the second conductive film is 5 nm or less.

11. In paragraph 1, The first surface of the graphene heating layer is in contact with the conductive layer, The above heating device, Further comprising an encapsulation layer covering a second side opposite to the first side of the graphene heating layer; A heating device wherein the encapsulation layer comprises an oxide metal material.

12. In paragraph 2, A heating device comprising a first conductive layer on which the first electrode is provided, and a second conductive layer spaced apart from the first conductive layer and on which the second electrode is provided.

13. In paragraph 12, The above graphene heating layer is, A first region in contact with the first conductive layer and spaced apart from the first electrode; A second region in contact with the second conductive layer and spaced apart from the second electrode, and A heating device comprising a third region positioned between the first region and the second region and arranged to be in contact with the base.

14. In paragraph 12, The first conductive layer includes a first conductive film in contact with the base, and a second conductive film disposed between the first conductive film and the graphene heating layer, A heating device comprising a third conductive film in contact with the base and a fourth conductive film disposed between the third conductive film and the graphene heating layer, wherein the second conductive layer comprises:

15. In paragraph 1, The above graphene heating layer is laminated on the conductive layer, The above heating device is a heating device configured to allow light to pass through.

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