Patent Description:
Recently, electronic products using a wireless power transfer (WPT) technology have been developed. Wireless power transfer technology is a technology for wirelessly transferring power between a power source and an electronic device. As an example, wireless power transfer technology allows you to charge the battery of a wireless terminal, such as a smartphone or tablet, by simply placing the wireless terminal on a wireless charging pad, thereby providing greater mobility, convenience, and safety compared to a wired charging environment in which an existing wired charging connector is used. Wireless power transfer technology is expected to replace an existing wired power transmission environment in various fields such as electric vehicles, various wearable devices such as Bluetooth earphones and 3D glasses, home appliances, furniture, underground facilities, buildings, medical devices, robots, and leisure.

A wireless power transfer method is referred to as a contactless power transfer method, a power transfer method having no point of contact, or a wireless charging method. A wireless power transfer system may be composed of a wireless power transmitter for supplying electric energy in the wireless power transfer method, and a wireless power receiver for receiving electric energy wirelessly supplied from the wireless power transmitter and supplying power to a power receiving device such as a battery cell.

Wireless power transfer technology includes various methods such as a method of transferring power through magnetic coupling, a method of transferring power through radio frequency (RF), a method of transferring power through microwaves, and a method of transferring power through ultrasonic waves.

Such a wireless power transfer technology is being applied to a small electric appliance in addition to wireless charging of a wireless terminal.

A wireless power technology is mainly divided into two categories such as a short distance and a long distance. In a short distance or non-radiative technology, power is generally transmitted over a short distance by a magnetic field using inductive coupling between coils of wire. Inductive coupling is the most widely used wireless technology.

<FIG> is a view illustrating an example of a small home appliance employing a conventional wireless power transfer technology.

Referring to <FIG>, an electric kettle is illustrated as the small home appliance.

Since the electric kettle <NUM> employs the wireless power transfer technology, the electric kettle is required to wirelessly receive power. To this end, the electric kettle <NUM> includes an antenna coil <NUM> for communication, and a coil <NUM> for power reception. The antenna coil <NUM> for communication and the coil <NUM> for power reception may be located close to each other due to the small internal area of the small home appliance. The coil <NUM> for power reception may receive power, and the antenna coil <NUM> for communication may, for example, be an antenna for a near field communication. The electric kettle <NUM> may perform near field communication with a wireless power transmission device <NUM> by using the antenna coil <NUM> for communication.

However, the magnitude of voltage induced in the antenna coil <NUM> for communication may be greater than the magnitude of voltage induced in the coil <NUM> for power reception. Accordingly, since the antenna coil <NUM> for communication and the coil <NUM> for power reception are located close to each other in the small space of the small home appliance, magnetic field interference occurs in the antenna coil <NUM> for communication due to the coil <NUM> for power reception, so communication performance deteriorates.

An example of the prior art is disclosed in the patent application published under the following number: <CIT>. <CIT> discloses a small home appliance comprising a coil for power reception and communication; a communication unit which performs wireless communication with a wireless power transmission device by using the coil; and a controller which receives wireless power from the wireless power transmission device by using the coil, receives a zero crossing interrupt signal related to the wireless power from the wireless power transmission, and determines a communication period for communication by using the coil according to the zero crossing interrupt signal, wherein the small home appliance is one of an electric kettle, a blender, and a toaster.

The present disclosure is intended to propose a small home appliance in which the problem of communication performance deterioration due to interference between a coil for power reception and a coil for communication in a conventional small home appliance is solved.

The present disclosure is intended to propose a small home appliance in which the space issue of the small home appliance can be solved.

The present disclosure is intended to propose a small home appliance and a method for performing communication with the small home appliance in which both power reception and communication can be performed by using one coil.

The objectives of the present disclosure are not limited to the objectives mentioned above, and, other objectives not mentioned will be clearly understood by those skilled in the art to which the present disclosure belongs from the following description.

According to the present invention, a small home appliance as defined in claim <NUM> is disclosed.

The controller may generate a communication control signal according to the zero crossing interrupt signal and transmit the communication control signal to the communication unit, and the communication unit may operate according to the communication control signal.

The wireless power transmission device may include a coil for power transmission which generates a time-varying electromagnetic field due to commercial power, a zero crossing detector which outputs a detected signal by detecting zero crossing of the commercial power, and another controller which generates the zero crossing interrupt signal on the basis of the detected signal.

The wireless power transmission device may further include: an antenna for communication, and another communication unit which communicates with the communication unit through the antenna for communication.

The zero crossing interrupt signal may have a period of <NUM>.

The zero crossing interrupt signal may have a pulse width of <NUM>.

The small electric appliance is one of an electric kettle, a blender, and a toaster.

The small home appliance may be the electric kettle, and the coil for power reception and communication may be disposed on the lower part of the electric kettle.

According to the present invention, a method for performing communication between the small home appliance and the wireless power transmission device according to claim <NUM> is disclosed.

The step of determining the communication period may include: a step at which the small home appliance generates the communication control signal according to the zero crossing interrupt signal; a step at which the small home appliance transmits the communication control signal to the communication unit of the small home appliance; and a step at which the communication unit of the small home appliance operates according to the communication control signal.

The method for performing communication may further include: a step at which zero crossing of commercial power is detected when the wireless power transmission device transmits wireless power by using the commercial power, and a step at which the wireless power transmission device generates the zero crossing interrupt signal according to the detected zero crossing.

According to the embodiment of the present disclosure, one coil is used for power and antenna, thereby solving the conventional problem of communication performance deterioration due to interference between two coils.

According to the embodiment of the present disclosure, coil mounting space is reduced, thereby improving the beauty of the small home appliance and miniaturizing the small home appliance.

Hereinbelow, detailed embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

<FIG> is a perspective view of an example of an electronic device employing a wireless power transfer system according to an embodiment of the present disclosure.

As an example of an electronic device, an electric kettle <NUM> is illustrated.

The electric kettle <NUM> may wirelessly receive power from a wireless power transmission device <NUM>. A coil <NUM> for power reception and communication (see <FIG>) of the electric kettle <NUM> may receive power from the wireless power transmission device <NUM> according to an electromagnetic induction method. The electromagnetic induction method is a method using an induction phenomenon between the primary and secondary coils of a transformer, and uses a frequency of several MHz. A transmission distance of the electromagnetic induction method is several mm or less, and a transmission efficiency thereof is about <NUM>% when the transmission distance is less than <NUM>.

In this case, when the electric kettle <NUM> is disposed close to the wireless power transmission device <NUM> within a predetermined distance, a current is applied to the coil of the wireless power transmission device <NUM> to form a magnetic field due to the flow of the current.

When the electric kettle <NUM> is located in the range of the magnetic field of the wireless power transmission device <NUM>, a current is induced in the coil of the electric kettle <NUM>. Accordingly, the electric kettle <NUM> may obtain AC power and convert the AC power into DC power such that the DC power can be supplied to components of the electric kettle <NUM>.

<FIG> is a block diagram of a small home appliance according to the embodiment of the present disclosure.

The small home appliance <NUM> may include the electric kettle, a blender, and a toaster. Furthermore, the small home appliance <NUM> may wirelessly receive power from the wireless power transmission device <NUM>.

The small home appliance <NUM> according to the embodiment of the present disclosure may include a first controller <NUM>, a first communication unit <NUM>, and the coil <NUM> for power reception and communication.

The small home appliance <NUM> may receive wireless power and may perform communication by using the coil <NUM> for power reception and communication. That is, the small home appliance <NUM> may perform both the reception of the wireless power and communication by using one coil.

Specifically, the first communication unit <NUM> may perform NFC communication by using the coil <NUM> for power reception and communication. Additionally, the first controller <NUM> may use voltage induced through the coil <NUM> for power reception and communication as power.

The first controller <NUM> may use the coil <NUM> for power reception and communication for communication according to a predetermined period. That is, the first controller <NUM> may determine a communication period by the coil <NUM>. That is, the first controller <NUM> may use the coil <NUM> for communication in a time period in which wireless power is not received through the coil <NUM>.

To this end, the first controller <NUM> may receive a zero crossing interrupt signal related to the wireless power from the wireless power transmission device <NUM>, and may determine a communication period by using the coil according to the zero crossing interrupt signal.

The wireless power transmission device <NUM> may include a second controller <NUM>, a second communication unit <NUM>, an antenna <NUM> for communication, a coil <NUM> for power transmission, and a zero crossing detector <NUM>.

Since the wireless power transmission device <NUM> does not have restriction of small space like the small home appliance <NUM>, the wireless power transmission device <NUM> may include the antenna <NUM> for communication and the coil <NUM> for power transmission. Accordingly, the second communication unit <NUM> may use the antenna <NUM> for communication exclusively for communication. Furthermore, the second controller <NUM> may use the coil <NUM> for power transmission exclusively for power transmission.

The coil <NUM> for power transmission may generate a time-varying electromagnetic field due to commercial power <NUM>. The commercial power <NUM> is AC power and thus has a zero crossing point. That is, commercial power is 220AC <NUM> in Korea and has <NUM> voltage zero crossing points.

Accordingly, the electromagnetic field generated due to the commercial power <NUM> may also have a zero crossing point. That is, in the zero crossing point of the time-varying electromagnetic field, wireless power may not be transmitted to the small home appliance <NUM>.

The zero crossing detector <NUM> may detect the zero crossing point of the commercial power and may provide or output a detected signal to the second controller <NUM>. The zero crossing detector <NUM> is not a necessary component of the small home appliance of the present disclosure, and may be included in the small home appliance <NUM> which is a wireless power reception device. The second controller <NUM> may generate a zero crossing interrupt signal on the basis of the detected signal output from the zero crossing detector <NUM>.

Meanwhile, since the commercial power <NUM> has a known frequency, the second controller <NUM> knows in advance the period of the commercial power. Accordingly, the second controller <NUM> may generate a zero crossing interrupt signal according to of the known period of the commercial power.

<FIG> illustrates a zero crossing interrupt signal according to the embodiment of the present disclosure. Referring to <FIG>, the zero crossing interrupt signal may be generated on the basis of the zero crossing of wireless power (WPT power in <FIG>). As described above, the zero crossing of commercial power or wireless power may be known in advance by the second controller <NUM> of the wireless power transmission device <NUM> or may be detected by the zero crossing detector <NUM>. For example, the zero crossing detector <NUM> may detect a sine waveform transition from positive and negative sections of wireless power.

The zero crossing interrupt signal may be generated based on the zero crossing of commercial power. As illustrated in <FIG>, the zero crossing interrupt signal may be a square wave signal having a period of <NUM>. Furthermore, the zero crossing interrupt signal may have a pulse width of <NUM>. The pulse width of the zero crossing interrupt signal may correspond to the negative section of wireless power. It is clear that embodiments of the present disclosure are not limited thereto.

The zero crossing interrupt signal may have a pulse width corresponding to the negative section of wireless power. In the negative section of wireless power, the coil <NUM> for power reception and communication of the small home appliance may be used for short distance communication (for example, NFC communication).

Referring back to <FIG>, the second controller <NUM> of the wireless power transmission device <NUM> may transmit a zero crossing interrupt signal to the small home appliance <NUM> through the second communication unit <NUM> on the basis of the zero crossing of wireless power.

When the first controller <NUM> of the small home appliance <NUM> receives the zero crossing interrupt signal through the first communication unit <NUM>, the first controller <NUM> may determine a communication period by using the coil <NUM> according to the zero crossing interrupt signal.

The first controller <NUM> of the small home appliance <NUM> may allow the first communication unit <NUM> to perform communication according to the determined communication period.

According to the embodiment, the small home appliance <NUM> may further include a switch <NUM> located between the coil <NUM> for power reception and communication and the first communication unit <NUM>. In this case, the first controller <NUM> may control the switch <NUM> according to the zero crossing interrupt signal.

Specifically, the first controller <NUM> may control the switch <NUM> according to the pulse of the zero crossing interrupt signal and may connect the coil <NUM> with the first communication unit <NUM>. For example, the first controller <NUM> may control the switch <NUM> by providing a switching signal to the switch <NUM>. When the first communication unit <NUM> is connected with the coil <NUM> through the switch <NUM>, the first communication unit <NUM> may transmit an NFC signal to the wireless power transmission device <NUM>.

According to another embodiment, when the first controller <NUM> of the small home appliance <NUM> receives the zero crossing interrupt signal from the wireless power transmission device <NUM>, the first controller <NUM> may generate a communication control signal. In this case, the communication control signal may be a signal indicating a communication period. After generating the communication control signal, the first controller <NUM> of the small home appliance <NUM> may transmit the communication control signal to the first communication unit <NUM>. When the first communication unit <NUM> receives the communication control signal from the first controller <NUM>, the first communication unit <NUM> may perform communication according to the communication control signal.

The small home appliance <NUM> may be an electric kettle, and the coil <NUM> for power reception and communication may be disposed on a lower part of the electric kettle <NUM>.

<FIG> illustrates a flowchart of the method of performing communication between the small home appliance and the wireless power transmission device according to the embodiment of the present disclosure.

Referring to <FIG>, the second controller <NUM> of the wireless power transmission device <NUM> may transmit wireless power to the small home appliance <NUM>. The wireless power transmission device <NUM> may transmit wireless power by using a coil for wireless power transmission (S410). When the second controller <NUM> of the wireless power transmission device <NUM> transmits wireless power, the second controller <NUM> may detect the zero crossing of wireless power (S420). The second controller <NUM> of the wireless power transmission device <NUM> may generate a zero crossing interrupt signal on the basis of the detected zero crossing of wireless power (S430).

After generating the zero crossing interrupt signal, the second controller <NUM> of the wireless power transmission device <NUM> may transmit the zero crossing interrupt signal to the small home appliance <NUM> (S440).

After receiving the zero crossing interrupt signal from the wireless power transmission device <NUM>, the first controller <NUM> of the small home appliance <NUM> may generate the communication control signal (S450). In this case, the communication control signal may be a signal indicating a communication period. After generating the communication control signal, the first controller <NUM> of the small home appliance <NUM> may transmit the communication control signal to the first communication unit <NUM> (S460). When receiving the communication control signal from the first controller <NUM>, the first communication unit <NUM> may perform communication according to the communication control signal.

According to the another embodiment, the first controller <NUM> of the small home appliance <NUM> may control the switch <NUM> disposed between the first communication unit <NUM> and the coil <NUM> for power reception and communication according to the zero crossing interrupt signal. Specifically, the first controller <NUM> may control the switch <NUM> by corresponding to the pulse of the zero crossing interrupt signal and may connect the coil <NUM> with the first communication unit <NUM>. When the first communication unit <NUM> is connected with the coil <NUM> through the switch <NUM>, the first communication unit <NUM> may transmit an NFC signal to the wireless power transmission device <NUM>.

<FIG> is a sectional view of an electric kettle which is an example of the small home appliance according to the embodiment of the present disclosure. <FIG> is a sectional perspective view of the electric kettle of <FIG>, and <FIG> is a sectional perspective view of the lower part of the electric kettle of <FIG>.

Referring to <FIG>, the electric kettle <NUM> may include a body <NUM>. The body <NUM> may be configured to have a cylindrical shape. A heater (not shown) may be installed on the lower surface <NUM> of the body <NUM>. The heater may receive power supplied from the electric kettle <NUM> and may generate heat. A handle <NUM> may be formed on a side of the body <NUM> by protruding therefrom.

Contents such as water may be received in the body <NUM>, and the lower surface <NUM> of the body <NUM> may be heated by the heater.

The body <NUM> may include an inner body <NUM> and an outer body <NUM> and may have space defined between the inner body <NUM> and the outer body <NUM>, so the body <NUM> may have a structure having a significantly improved insulation performance compared to a single-wall structure.

Both the inner body <NUM> and the outer body <NUM> may be formed of the same stainless materials, wherein the outer body <NUM> may constitute the exterior of the body <NUM>, and the inner body <NUM> may define the space in which water is received. The inner body <NUM> may have a diameter smaller than the diameter of the outer body <NUM>, and accordingly, the inner body <NUM> may be provided to be received in the outer body <NUM>. Accordingly, the space <NUM> may be defined between the outer body <NUM> and the inner body <NUM>.

An air layer may be formed in the space <NUM> defined between the outer body <NUM> and the inner body <NUM>, so heat may be prevented from being directly transferred to the outer body <NUM>. Accordingly, the space <NUM> may be referred to as insulation space <NUM>. Additionally, even in a state in which water received in the inner body <NUM> is heated to be hot, the outer body <NUM> may maintain a relatively low temperature.

The body <NUM> may be formed in such a manner that the upper and lower ends of the outer body <NUM> and the inner body <NUM> formed in cylindrical shapes are coupled to each other. For example, the upper and lower ends of the outer body <NUM> and the inner body <NUM> may be connected to each other by welding while superimposed on each other. In this case, except for the upper and lower ends of the outer body <NUM> and the inner body <NUM>, remaining portions thereof may be spaced apart by a predetermined interval from each other to have an insulating structure.

The structure of the upper end of the body <NUM> will be described in more detail. A outer lower end part <NUM> may be formed on the lower end of the outer body <NUM>. The outer lower end part <NUM> may extend downward to form the lower end of the outer body <NUM>, and may be formed in a shape stepped inward.

An inner lower end part <NUM> may be formed on the lower end of the inner body <NUM>. The inner lower end part <NUM> may be formed by extending downward to form the lower end of the inner body <NUM>. Furthermore, the inner lower end part <NUM> may be in surface contact with the outer lower end part <NUM>. In a state in which the outer lower end part <NUM> and the inner lower end part <NUM> are coupled to each other, the coil <NUM> for power reception and communication of the electric kettle <NUM> may be installed in space between the outer lower end part <NUM> and the inner lower end part <NUM>.

As described above, as a distance between the coil <NUM> of the electric kettle <NUM> and the coil of the wireless power transmission device <NUM> decreases, power transmission efficiency therebetween increases. Accordingly, when the coil <NUM> of the electric kettle <NUM> is placed on the wireless power transmission device <NUM>, the coil <NUM> may be disposed in the space between the outer lower end part <NUM> and the inner lower end part <NUM> close to the coil of the wireless power transmission device <NUM>.

In addition, a humidity sensor <NUM> may be installed in the space between the outer lower end part <NUM> and the inner lower end part <NUM>. The humidity sensor <NUM> may be installed to be exposed to space of the body <NUM> in which water is received. Specifically, the humidity sensor <NUM> may be installed on a side portion of the inner lower end part <NUM> such that the humidity sensor <NUM> is exposed to the space of the body <NUM> in which water is received. Accordingly, the humidity sensor <NUM> may measure the humidity of the space of the body <NUM> in which water is received.

Claim 1:
A small home appliance (<NUM>) comprising:
a coil for power reception and communication; a communication unit (<NUM>) which performs wireless communication with a wireless power transmission device (<NUM>) by using the coil; a switch (<NUM>) located between the coil and the communication unit (<NUM>); and a controller (<NUM>) which receives wireless power from the wireless power transmission device (<NUM>) by using the coil, receives a zero crossing interrupt signal related to the wireless power from the wireless power transmission device (<NUM>), controls the switch (<NUM>) according to the zero crossing interrupt signal, and determines a communication period for communication by using the coil according to the zero crossing interrupt signal,
wherein the small home appliance (<NUM>) is one of an electric kettle, a blender, and a toaster.