Patent Description:
In modern society, many different technologies to improve performance of displays and speaker systems compatible with the displays are being developed.

For the display system, various methods for supplying power to the display and speaker are also being discussed. Technologies for wireless power transmission that supply power without using power cables have recently received much attention. If the wireless power transmission technology is commercialized, it may supply energy easily and transmit power without entangled wires that are otherwise equipped in the display system, as compared to wired charging systems currently in use.

Of those wireless power transmission technologies, one based on magnetic resonance receives power from an alternate current (AC) source and generates an AC current in a transmit coil coupled with a resonance coil, enabling the resonance coil to transmit power. The wireless power transmission based on the magnetic resonance may transmit power father away than in the electromagnetic method, but needs to be more improved because the transmittable range is still short.

It also requires extra devices and circuits to secure a wireless power transmission range, which increases material costs, reduces efficiency, and causes power loss.

Furthermore, a method of efficiently reducing electromagnetic interference (EMI) due to leakage of a magnetic field caused by the wireless power transmission is becoming more important these days.

<CIT> describes an electronic device and method for wirelessly receiving power. <CIT> describes transmitters for wireless power transfer. <CIT> describes adaptive multi-pathway wireless charging. <CIT> describes a charging station that wirelessly transmits power to mobile electronic devices. <CIT> describes systems for wirelessly transmitting power to an implanted medical device.

The disclosure provides a wireless power relaying device for transmitting power wirelessly characterized to have such a structure that smoothly transmits wireless power to a display device and reduces electromagnetic interference (EMI) caused by wireless power transmission.

Provided are a wireless power relaying device according to claim <NUM> and a system according to claim <NUM>.

According to embodiments of the disclosure, a wireless power relaying device for transmitting power wirelessly is characterized to have such a structure that smoothly transmits wireless power to a display device and reduces EMI caused by wireless power transmission. Furthermore, a speaker arranged near the display device may be used as the wireless power relaying device to transmit power wirelessly, to secure aesthetic and design benefits of the display system.

The above and other objects, features and advantages of the present disclosure will become more apparent to those of ordinary skill in the art by describing in detail exemplary embodiments thereof with reference to the accompanying drawings, in which:.

Advantages, features, and methods for achieving them will be understood more clearly when the following embodiments are read with reference to the accompanying drawings.

Embodiments and features as described and illustrated in the present disclosure are only preferred examples, and various modifications thereof may also fall within the scope of the disclosure.

The terms as used throughout the specification, such as "∼ part", "∼ module", "∼ member", "∼ block", etc., may be implemented in software and/or hardware, and a plurality of "∼ parts", "∼ modules", "∼ members", or "∼ blocks" may be implemented in a single element, or a single "∼ part", "∼ module", "∼ member", or "∼ block" may include a plurality of elements.

It will be further understood that the term "connect" or its derivatives refer both to direct and indirect connection, and the indirect connection includes a connection over a wireless communication network.

The terms including ordinal numbers like "first" and "second" may be used to explain various components, but the components are not limited by the terms. The terms are only for the purpose of distinguishing a component from another. For example, a first element could be termed a second element and vice versa, without departing from the scope of the disclosure. Descriptions shall be understood as to include any and all combinations of one or more of the associated listed items when the items are described by using the conjunctive term "∼ and/or ∼," or the like.

Embodiments of a wireless power relaying device and a display system that receives power wirelessly will be described in detail with reference to accompanying drawings. Like reference numerals refer to like components throughout the drawings, and thus the related descriptions that overlap will be omitted.

<FIG> shows a display system, according to an embodiment of the disclosure.

Referring to <FIG>, a display system <NUM> may include a wireless power transmitter <NUM>, a speaker <NUM>, and a display <NUM>.

The display <NUM> may be implemented in a screen type such as to display a television (TV) screen. Recently, the display <NUM> has a tendency to get slimmer without bezels, and the speaker of the display <NUM> is implemented as being separated from the display <NUM>.

Accordingly, as shown in <FIG>, the speaker <NUM> may be shaped like a sound bar that is physically separated from the display <NUM>, emitting sound in the forward direction to improve output sound quality.

As will be described later, the speaker <NUM> according to an embodiment of the disclosure may be implemented as a wireless power relaying device equipped with a resonator therein to receive wireless power from the wireless power transmitter <NUM> and transmit the wireless power to the display <NUM>.

A resonant circuit provided in the speaker <NUM> may be designed to drive an internal circuit for a function of the speaker <NUM> as well as to wirelessly forward the power to the display <NUM>.

In the display system <NUM>, the display <NUM> may be implemented in a wall-mounted TV type, and various connecting jacks included in the display <NUM> are arranged in a separate jack pack to be easily connected to an external device.

For example, a high definition multimedia interface (HDMI) terminal, an antenna connecting terminal, an input/output terminal, etc., may be arranged in the jack pack, and in an embodiment of the disclosure, the wireless power transmitter <NUM> may be implemented with the jack pack. In another embodiment of the disclosure, the wireless power transmitter <NUM> may be implemented with a set-top box, without being limited thereto.

The wireless power transmitter <NUM> implemented in the jack pack type, the speaker <NUM> serving as a wireless power relaying device to wirelessly transmit power to the display <NUM>, and the display <NUM> implemented in a wall-mounted TV type may make the display system <NUM> wireless and secure convenient connectivity and aesthetic benefits of the display system <NUM>.

The display system <NUM> may wirelessly transmit or receive power and output content through components included in the display system <NUM>. For example, the content may be stored in the display system <NUM> or received from an external device, e.g., a set-top box, a jack pack, a digital versatile disk (DVD) player, etc. The content may include image information and sound information.

In an embodiment of the disclosure, the display system <NUM> may distribute power wirelessly to the respective components to display the content.

In an embodiment of the disclosure, the wireless power transmitter <NUM> may be connected to an external power source <NUM> to receive power. The external power source <NUM> may apply an alternate current (AC) voltage in a designated range, e.g., from about <NUM> to about <NUM> volts (V) of a wall power source or a commercial power source, to the display system <NUM>.

In an embodiment of the disclosure, the wireless power transmitter <NUM> may transmit power supplied from the external power source <NUM> to an external device. For example, the wireless power transmitter <NUM> may transmit a first power signal <NUM> to an external device, e.g., the speaker <NUM> based on the input or supplied power. For example, the first power signal <NUM> may be a signal to wirelessly transmit power generated by an input power source, e.g., the external power source <NUM>.

In an embodiment of the disclosure, the wireless power transmitter <NUM> may generate the first power signal <NUM> by producing a magnetic field through a power transmit coil <NUM> (see <FIG>) provided on a power transmit magnetic body <NUM>. Accordingly, the wireless power transmitter <NUM> may transmit the first power signal <NUM> to the speaker <NUM> by converting the power supplied from the external power source <NUM> to a magnetic field (or a first magnetic field).

In an embodiment of the disclosure, the wireless power transmitter <NUM> may supply power to the external device not only wirelessly but also wiredly.

For example, the wireless power transmitter <NUM> may supply power to an external device wiredly connected thereto. For example, the external device may be a device for performing an additional function.

In an embodiment of the disclosure, the speaker <NUM> may relay the power transmitted from the wireless power transmitter <NUM> to the external device. For example, the speaker <NUM> may receive the first power signal <NUM> from the wireless power transmitter <NUM> and transmit a second power signal <NUM> to the external device based on the received first power signal <NUM>.

For example, the second power signal <NUM> may be generated based on part of the power received through the first power signal <NUM>.

In an embodiment of the disclosure, the speaker <NUM> may relay power with a relay coil <NUM> (see <FIG>) provided on a relay magnetic body <NUM> when induced electromotive force is generated in the relay coil <NUM> by a magnetic field produced by the wireless power transmitter <NUM> and the induced electromotive force produces a magnetic field.

In an embodiment of the disclosure, the speaker <NUM> may output a designated sound. For example, the speaker <NUM> may output a sound included in the content based on part of the first power signal <NUM> received from the wireless power transmitter <NUM>. As such, the speaker <NUM> may output the designated sound while relaying power to the external device.

In an embodiment of the disclosure, the speaker <NUM> may be a wireless power relaying device that relays the power signal, e.g., the first power signal <NUM>, transmitted from the wireless power transmitter <NUM> to the display <NUM>. The wireless power relaying device may be implemented with a relay, a repeater, or the like. The wireless power relaying device may output a sound included in the content.

In an embodiment of the disclosure, the display <NUM> may receive power from the speaker <NUM>. In other words, the display <NUM> may receive the power forwarded or relayed by the speaker <NUM>. For example, the display <NUM> may receive the second power signal <NUM>.

In an embodiment of the disclosure, the display <NUM> may include a display coil <NUM> provided on a display magnetic body <NUM>, and receive the second power signal <NUM> as the display coil <NUM> resonates with a magnetic field produced by the speaker <NUM> and produces induced electromotive force.

According to an embodiment of the disclosure, the display <NUM> may output a designated image by using the received power signal, e.g., the second power signal <NUM>, and the designated image may be included in the content.

As described above, the display system <NUM> may include the display <NUM>, the speaker <NUM>, and the wireless power transmitter <NUM>, and transmit or receive content in a power signal through wireless power transmission or reception between the components.

In this case, electromagnetic interference (EMI) might be caused by a leaked magnetic field generated due to the wireless power transmission, and might have an influence on transmission or reception of the content, so a need to reduce the EMI is ever increasing.

In the display system <NUM> according to an embodiment of the disclosure, a wireless power relaying device for transmitting power wirelessly is designed to have such a structure that smoothly transmits wireless power to the display <NUM> and reduce EMI caused by the wireless power transmission.

<FIG> is a block diagram of a wireless power relaying device and a display system, according to an embodiment of the disclosure, and <FIG> is a circuit diagram of a wireless power relaying device and a display system, according to an embodiment of the disclosure.

Referring to <FIG>, the display <NUM> of the display system <NUM> may include an image output module <NUM> and a display magnetic body <NUM>, around which the display coil <NUM> may be wound.

The display magnetic body <NUM> may include a first display magnetic body <NUM>-<NUM> and a second display magnetic body <NUM>-<NUM> arranged a predefined distance away from the first display magnetic body <NUM>-<NUM>, and the display coil <NUM> may be wound around each of the first and second display magnetic bodies <NUM>-<NUM> and <NUM>-<NUM> in the same direction. The predefined distance between the first and second display magnetic bodies <NUM>-<NUM> and <NUM>-<NUM> may be set depending on the arrangement of the display magnetic body <NUM> in the design of the display <NUM>.

The speaker <NUM> of the display system <NUM> may be implemented as a wireless power relaying device. In an embodiment of the disclosure, the speaker <NUM> may include a relay magnetic body <NUM>, around which the relay coil <NUM> may be wound.

The speaker <NUM> includes a power supply coil <NUM> wound around the relay magnetic body <NUM>.

Furthermore, the speaker <NUM> may include a load module <NUM> that performs a function of the speaker <NUM> using the received power, and the load module <NUM> may be implemented as a sound output module <NUM> that outputs sound.

The relay magnetic body <NUM> may include a first relay magnetic body <NUM>-<NUM>, a second relay magnetic body <NUM>-<NUM>, and a third relay magnetic body <NUM>-<NUM>, which are separated from one another by a predefined distance.

For example, the second relay magnetic body <NUM>-<NUM> may be arranged the predefined distance away from one end of the first relay magnetic body <NUM>-<NUM>, and the third relay magnetic body <NUM>-<NUM> may be arranged the predefined distance away from the other end of the first relay magnetic body <NUM>-<NUM>.

In other words, as shown in <FIG>, in the speaker <NUM>, the first relay magnetic body <NUM>-<NUM> is located in the middle and the second and third relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM> are located on either side of the first relay magnetic body <NUM>-<NUM>.

The predefined distance between the first, second, and third relay magnetic bodies <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM> may be set depending on the arrangement of the relay magnetic body <NUM> in the design of the speaker <NUM>.

The relay coil <NUM> may be wound around each of the first to third relay magnetic bodies <NUM>-<NUM> to <NUM>-<NUM>. For example, as shown in <FIG>, relay coil <NUM> can include a plurality of relay coils, with a relay coil (or multiple relay coils as shown in <FIG>) being wound around the first relay magnetic body <NUM>-<NUM>, another relay coil being wound around the second relay magnetic body <NUM>-<NUM>, and another relay coil being wound around the third relay magnetic body <NUM>-<NUM>.

The relay coils <NUM> wound around the first to third relay magnetic bodies <NUM>-<NUM> to <NUM>-<NUM> are connected in series to each other.

As shown in <FIG>, a direction in which the relay coil <NUM> is wound around the first relay magnetic body <NUM>-<NUM> and directions in which the relay coils <NUM> are wound around the second and third relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM> are different, and the directions in which the relay coils <NUM> are wound around the second and third relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM> may be the same.

As the direction in which the relay coil <NUM> is wound around the first relay magnetic body <NUM>-<NUM> is opposite the directions in which the relay coil <NUM> is wound around each of the second and third relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM>, the leaked magnetic field may be canceled out, thereby reducing EMI. This will be described in detail in connection with <FIG>.

The number of turns of the relay coil <NUM> wound around the second relay magnetic body <NUM>-<NUM> is the same as the number of turns of the relay coil <NUM> wound around the third relay body <NUM>-<NUM>, and each of the number of turns of the relay coil <NUM> wound around the second relay magnetic body <NUM>-<NUM> and the number of turns of the relay coil <NUM> wound around the third relay body <NUM>-<NUM> may be less than the number of turns of the relay coil <NUM> wound around the first relay magnetic body <NUM>-<NUM> by a predetermined number of turns.

Depending on mutual inductance of the relay coils <NUM> wound around the second and third relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM>, inductance of the relay coil <NUM> wound around the first relay magnetic body <NUM>-<NUM> increases or decreases. Accordingly, the number of turns of the relay coils <NUM> wound around the second and third relay magnetic bodies <NUM>-<NUM> or <NUM>-<NUM> may be determined in such a range that magnetic fields produced from the relay coils <NUM> wound around the second and third relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM> cancel out the leaked magnetic field produced from the relay coil <NUM> wound around the first relay magnetic body <NUM>-<NUM> without significantly reducing inductance L1 of the first relay magnetic body <NUM>-<NUM>.

For example, when the number of turns of the relay coil <NUM> wound around the first relay magnetic body <NUM>-<NUM> is <NUM>, the number of turns of the relay coil <NUM> wound around each of the second and third relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM> may be <NUM>.

The speaker <NUM> further includes a power supply circuit <NUM> for supplying power to the speaker <NUM>, and the power supply circuit <NUM> includes a power supply coil <NUM> wound around the first relay magnetic body <NUM>-<NUM>, and the sound output module <NUM> that corresponds to a load for performing a function based on the supplied power.

The power supply coil <NUM> is wound in the same direction as the direction in which the relay coil <NUM> is wound around the first relay magnetic body <NUM>-<NUM>.

Unlike in the prior art that supplies power using an active device composed of R (resistor), L (inductor), and C (capacitor), a passive device including only L and C with the power supply coil <NUM> provided on the first relay magnetic body <NUM>-<NUM>, is used in an embodiment of the disclosure to supply power to the speaker <NUM>, so that power loss is reduced and the need for additional circuit installation is eliminated.

The wireless power transmitter <NUM> of the display system <NUM> may include a power transmit magnetic body <NUM>, around which a power transmit coil <NUM> may be wound.

The wireless power transmitter <NUM> may be connected to the external power source <NUM> to receive power. The external power source <NUM> may apply an AC voltage in a designated range, e.g., from about <NUM> to about <NUM> volts (V) of a wall power source or a commercial power source, to the display system <NUM>.

In an embodiment of the disclosure, the wireless power transmitter <NUM> may transmit the first power signal <NUM> to the speaker <NUM> by converting the power supplied from the power source <NUM> to a first magnetic field <NUM>.

The relay coil <NUM> provided on the relay magnetic body <NUM> of the speaker <NUM> may produce a second magnetic field <NUM> by a first current induced from the first magnetic field <NUM> produced from the wireless power transmitter <NUM>.

The speaker <NUM> may forward the second power signal <NUM> to the display <NUM> through the second magnetic field <NUM> produced by the relay coil <NUM> provided on the relay magnetic body <NUM>. Specifically, the second current is induced in the display coil <NUM> provided on the display magnetic body <NUM> by the second magnetic field <NUM> produced from the relay coil <NUM> of the speaker <NUM>, so that the second power signal <NUM> may be forwarded from the speaker <NUM> to the display <NUM>.

The display coil <NUM> provided on the display magnetic body <NUM> of the display <NUM> may produce a third magnetic field <NUM> by the second current induced from the second magnetic field <NUM> produced from the speaker <NUM>.

The image output module <NUM> of the display <NUM> may output an image on the screen based on the power forwarded through the second current induced from the second magnetic field <NUM>.

Specifically, referring to <FIG>, when AC power is applied to the wireless power transmitter <NUM> from the power source <NUM>, the power transmit magnetic body <NUM> produces the first magnetic field <NUM> due to the current flowing in the power transmit coil <NUM>.

The first magnetic field <NUM> produced from the power transmit magnetic body <NUM> induces the first current that corresponds to an induced current in the relay coil <NUM> provided on the relay magnetic body <NUM> of the speaker <NUM>.

The relay coil <NUM> may produce the second magnetic field <NUM> by the first current, and a direction of the second magnetic field <NUM> is opposite the direction of the first magnetic field <NUM>.

Specifically, the first magnetic field <NUM> produced from the power transmit magnetic body <NUM> causes an induced current to flow in the relay coil <NUM> of the speaker <NUM>, and the second magnetic field <NUM> is produced on and around the relay magnetic body <NUM> according to Lenz's law about the direction of electromagnetic induction.

As shown in <FIG>, the first magnetic field <NUM> induces the first current in the entire relay coil <NUM> provided on the first to third relay magnetic bodies <NUM>-<NUM> to <NUM>-<NUM> of the speaker <NUM>, and the first current produces the second magnetic field <NUM> on and around each of the first to third relay magnetic bodies <NUM>-<NUM> to <NUM>-<NUM> of the speaker <NUM>.

The speaker <NUM> may forward the second power signal <NUM> to the display <NUM> through the second magnetic field <NUM>.

The second magnetic field <NUM> produced from the relay magnetic body <NUM> of the speaker <NUM> induces the second current that corresponds to an induced current in the display coil <NUM> provided on the display magnetic body <NUM> of the display <NUM>.

The display coil <NUM> may produce the third magnetic field <NUM> by the second current, and a direction of the third magnetic field <NUM> is opposite the direction of the second magnetic field <NUM>.

Specifically, the second magnetic field <NUM> produced from the relay magnetic body <NUM> causes an induced current to flow in the display coil <NUM> of the display <NUM>, and the third magnetic field <NUM> is produced on and around the display magnetic body <NUM> according to Lenz's law.

As shown in <FIG>, the second magnetic field <NUM> from the relay coil <NUM> provided on the first relay magnetic body <NUM> induces the second current in the entire display coils <NUM> provided on the first and second display magnetic bodies <NUM>-<NUM> to <NUM>-<NUM> of the display <NUM>, and the second current produces the third magnetic field <NUM> on and around each of the first and second display magnetic bodies <NUM>-<NUM> to <NUM>-<NUM>.

As described above, the first magnetic field <NUM> is produced from the wireless power transmitter <NUM>, and the third magnetic field <NUM> is produced in the display <NUM>.

In this case, when there is a phase difference as much as <NUM> ° between the first and third magnetic fields <NUM> and <NUM>, a leaked magnetic field caused from the first magnetic field <NUM> is canceled out by the third magnetic field <NUM>, thereby reducing EMI created from the first magnetic field <NUM>.

As such, with the speaker <NUM> installed between the wireless power transmitter <NUM> and the display <NUM> to transmit power in a wireless power relaying method, the magnetic field from the wireless power transmitter <NUM> and the magnetic field in the display <NUM> may cancel each other out, thereby reducing creation of EMI due to the leaked magnetic field.

Such a method of reducing EMI based on phase difference between magnetic fields will be described in connection with <FIG>.

<FIG> shows graphs for explaining phase differences between currents flowing in a power transmit coil, a relay coil, and a display coil, according to an embodiment of the disclosure.

Referring to <FIG>, in a design where the power transmit coil <NUM> of the wireless power transmitter <NUM> operates in an inductive area; the relay coil <NUM> of the speaker <NUM> operates in a capacitive area; and the display coil <NUM> of the display <NUM> operates at a resonance frequency, there is a phase difference of <NUM> ° between a current flowing in the power transmit coil <NUM> and a current flowing in the display coil <NUM>.

As shown in <FIG>, for example, when the resonance frequency of the power transmit coil <NUM> is <NUM> and the frequency of an AC magnetic field is <NUM>, the resonance frequency of the power transmit coil <NUM> is higher than the switching frequency of the AC magnetic field, so the power transmit coil <NUM> is in the inductive area where the switching frequency of the AC magnetic field is located farther to the right than the resonance frequency of the power transmit coil <NUM> on a coordinate axis of resonance frequency.

In another example, when the resonance frequency of the relay coil <NUM> is <NUM> and the frequency of the AC magnetic field is <NUM>, the resonance frequency of the relay coil <NUM> is lower than the switching frequency of the AC magnetic field, so the relay coil <NUM> is in the capacitive area where the switching frequency of the AC magnetic field is located farther to the left than the resonance frequency of the relay coil <NUM> on a coordinate axis of resonance frequency.

For the display coil <NUM> of the display <NUM>, the resonance frequency and the switching frequency of the AC magnetic field corresponds to each other at <NUM> for maximum efficiency of power transfer.

When the power transmit coil <NUM>, the relay coil <NUM>, and the display coil <NUM> are designed to operate with the aforementioned settings, there is a phase difference of <NUM> ° between the current flowing in the power transmit coil <NUM> and the current flowing in the relay coil <NUM> and between the current flowing in the relay coil <NUM> and the current flowing in the display coil <NUM>, and as a result, there is a phase difference of <NUM> ° between the current flowing in the power transmit coil <NUM> and the current flowing in the display coil <NUM>.

Accordingly, with the phase difference of <NUM> ° between the first magnetic field <NUM> produced from the wireless power transmitter <NUM> and the third magnetic field <NUM> produced from the display <NUM>, a leaked magnetic field caused from the first magnetic field <NUM> is canceled out by the third magnetic field <NUM>, thereby reducing EMI created from the first magnetic field <NUM>.

In the meantime, although the leaked magnetic field may be reduced in the aforementioned method by locating the speaker <NUM> between the wireless power transmitter <NUM> and the display <NUM>, when there is only one relay magnetic body <NUM> provided in the speaker <NUM>, a leaked magnetic field may be caused from the second magnetic field <NUM> produced from the speaker <NUM>.

Accordingly, to reduce EMI due to the leaked magnetic field caused from the speaker <NUM>, the second and third relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM> may be located on either side of the first relay magnetic body <NUM>-<NUM> of the speaker <NUM>, to cancel out the leaked magnetic field caused from the first relay magnetic body <NUM>-<NUM>.

As shown in <FIG>, the second relay magnetic body <NUM>-<NUM> may be arranged a predefined distance away from one end of the first relay magnetic body <NUM>-<NUM>, and the third relay magnetic body <NUM>-<NUM> may be arranged the predefined distance away from the other end of the first relay magnetic body <NUM>-<NUM>. As described above, the predefined distance between the first, second, and third relay magnetic bodies <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM> may be set depending on the arrangement of the relay magnetic body <NUM> in the design of the speaker <NUM>.

The relay coil <NUM> is wound around each of the first to third relay magnetic bodies <NUM>-<NUM> to <NUM>-<NUM> and is connected in series to each other.

A direction in which the relay coil <NUM> is wound around the first relay magnetic body <NUM>-<NUM> and directions in which the relay coils <NUM> are wound around the second and third relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM> are different, and the directions in which the relay coils <NUM> are wound around the second and third relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM> are the same.

Specifically, as shown in <FIG>, for the three relay magnetic bodies <NUM>, a direction in which the relay coil <NUM> is wound around a relay magnetic body located in the middle is opposite directions in which the relay coils <NUM> are wound around relay magnetic bodies located on the left and right.

With the winding directions of the relay coils <NUM>, the leaked magnetic field caused from the second magnetic field <NUM> produced from the first relay magnetic body <NUM>-<NUM> is canceled out by the second magnetic field <NUM> produced from the second and third relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM>, thereby reducing EMI.

In other words, the magnetic field produced from the first relay magnetic body <NUM>-<NUM> has an opposite direction to and is canceled out by the magnetic field produced from the second and third relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM>, so that the leaked magnetic field may be reduced.

It is also possible for the relay coils <NUM> to be wound around the first to third relay magnetic bodies <NUM>-<NUM> to <NUM>-<NUM> in the opposite directions to what are shown in <FIG>.

In the meantime, when the distance between the first and second relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM> and between the first and third relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM> is too short, the second magnetic fields <NUM> produced from the relay coils <NUM> cancel each other out and die off, leading to wireless power transmission loss. Hence, the distance between the first relay magnetic body <NUM>-<NUM> and the second relay magnetic body <NUM>-<NUM> on the left and between the first relay magnetic body <NUM>-<NUM> and the third relay magnetic body <NUM>-<NUM> on the right needs to be set to a predefined suitable distance, which is not too short.

The distance between the first and second relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM> and between the first and third relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM> may be set to such a distance that prevents the second magnetic fields <NUM> produced from the relay coils <NUM> from canceling each other out and dying off in the design of the speaker <NUM>.

In other words, in designing the speaker <NUM>, the predefined distance between the first, second, and third relay magnetic bodies <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> may be determined by taking into account both magnetic field cancellation conditions and wireless power transmission loss conditions, and the first to third relay magnetic bodies <NUM>-<NUM> to <NUM>-<NUM> may be arranged according to the determined distance.

In this case, the distance between the first and second relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM> and the distance between the first and third relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM> may be the same. Specifically, the distance between the first and second relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM>, which is called a first distance, and the distance between the first and third relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM>, which is called a second distance, may be the same or different from each other depending on arrangement relations of the first to third relay magnetic bodies <NUM>-<NUM> to <NUM>-<NUM>.

The reason why the distance between the first to third relay magnetic bodies <NUM>-<NUM> to <NUM>-<NUM> needs to be appropriately adjusted and spaced will now be described in detail.

For example, as the relay coil <NUM> wound around the first relay magnetic body <NUM>-<NUM> having inductance L1 and the relay coil <NUM> wound around each of the second and third relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM> having inductance L2 are connected in series and the winding directions thereof are opposite as described above, total inductance is <MAT>.

k is a coupling coefficient of the relay coil <NUM>, having a value between <NUM> and <NUM>.

For example, when L1 = <NUM>. 3mH, L2 = <NUM>. 47mH, k = <NUM>, the total inductance L = <NUM>. 25mH according to the above equation.

Based on the above equation, the total inductance L= <NUM>. 25mH, is less than the inductance L1=<NUM>. 3mH, of the relay coil <NUM> wound around the first relay magnetic body <NUM>-<NUM> by <NUM>.

The inductance L1 of the relay coil <NUM> wound around the first relay magnetic body <NUM>-<NUM> plays a role of relaying a magnetic field produced from the wireless power transmitter <NUM>, and when the total inductance is reduced due to the relay coils <NUM> wound around the second and third magnetic bodies <NUM>-<NUM> and <NUM>-<NUM> in the other direction, the wireless power transmission efficiency deteriorates.

On the other hand, when k is <NUM>, the total inductance L is <NUM>. 35mH, which is larger than the inductance L1=<NUM>. 3mH, of the relay coil wound around the first relay magnetic body <NUM>-<NUM> by <NUM>.

In order to reduce the value of the coupling coefficient k of the relay coil <NUM>, the distance between the relay coil <NUM> wound around the first relay magnetic body <NUM>-<NUM> and the relay coil <NUM> wound around the second or third relay magnetic body <NUM>-<NUM> or <NUM>-<NUM> needs to be widened, or the number of turns of the relay coil <NUM> wound around the second or third relay magnetic body <NUM>-<NUM> or <NUM>-<NUM> needs to be adjusted.

The aim of embodiments of the disclosure is to reduce EMI caused by a leaked magnetic field without deterioration of wireless power transmission efficiency, so the number of turns of the relay coil <NUM> wound around the second or third relay magnetic body <NUM>-<NUM> or <NUM>-<NUM> and the distance between the relay coils <NUM> wound around the magnetic bodies need to be adjusted in order to prevent the total inductance L from being less than the inductance L1 of the relay coil <NUM> wound around the first relay magnetic body <NUM>-<NUM>.

The inductance L1 of the relay coil <NUM> wound around the first relay magnetic body <NUM>-<NUM> may be obtained with a sufficient number of turns of the relay coil <NUM> in such a range that prevents the first relay magnetic body <NUM>-<NUM> from being saturated.

As such, for the relay magnetic body <NUM> of the display system <NUM> according to an embodiment of the disclosure, when the relay coil <NUM> wound around the first relay magnetic body <NUM>-<NUM> and the relay coils <NUM> wound around the second and third relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM> are connected in series to each other, the number of turns of the relay coils <NUM> and the distance between the relay coils <NUM> may be adjusted for the total inductance L to be equal to or larger than the inductance L1 of the relay coil <NUM> wound around the first relay magnetic body <NUM>-<NUM>.

As shown in <FIG>, the number of turns of the relay coil <NUM> wound around the second relay magnetic body <NUM>-<NUM> is the same as the number of turns of the relay coil <NUM> wound around the third relay body <NUM>-<NUM>, and the number of turns of the relay coil <NUM> wound around the second relay magnetic body <NUM>-<NUM> and the number of turns of the relay coil <NUM> wound around the third relay body <NUM>-<NUM> may each be less than the number of turns of the relay coil <NUM> wound around the first relay magnetic body <NUM>-<NUM> by a predetermined number of turns.

In this case, the number of turns of the relay coil <NUM> wound around each of the second and third relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM>, which is less than the number of turns of the relay coil <NUM> wound around the first relay magnetic body <NUM>-<NUM>, may be set by taking into account the total inductance L and the inductance L1 of the coil <NUM> wound around the first relay magnetic body <NUM>-<NUM> as described above.

Depending on the mutual inductance of the relay coils <NUM> wound around the second and third relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM>, the inductance L1 of the relay coil 115wound around the first relay magnetic body <NUM>-<NUM> increases or decreases. Accordingly, the number of turns of the relay coils <NUM> wound around the second and third relay magnetic bodies <NUM>-<NUM> or <NUM>-<NUM> may be determined in such a range that magnetic fields produced from the relay coils <NUM> wound around the second and third relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM> cancel out the leaked magnetic field produced from the relay coil <NUM> wound around the first relay magnetic body <NUM>-<NUM> without significantly reducing inductance L1 of the first relay magnetic body <NUM>-<NUM>.

The display system <NUM> according to the embodiment of the disclosure uses the speaker <NUM> as a wireless power relaying device to wirelessly transmit power to the display <NUM> while supplying power to the sound output module <NUM> provided in the speaker <NUM>.

In order for the speaker <NUM> to efficiently relay wireless power to the display <NUM>, a sufficient current is required to flow in the relay coils <NUM> of the speaker <NUM> to produce the second magnetic fields <NUM>.

Specifically, when the relay coil <NUM> is connected directly to the sound output module <NUM> to supply power to the sound output module <NUM>, a load resistor of the sound output module <NUM> hinders a sufficient current flowing in the relay coil <NUM>.

Hence, according to an embodiment of the disclosure, in order for a sufficient current to flow in the relay coil <NUM> of the speaker <NUM> while smoothly sending power to the sound output module <NUM>, the power supply coil <NUM> may be wound around the relay magnetic body <NUM> with a predefined distance to the relay coil <NUM> so that the relay coil <NUM> for relaying power and the power supply coil <NUM> for sending power to the sound output module <NUM> are physically separated.

Referring to <FIG> and <FIG>, the speaker <NUM> further includes the power supply circuit <NUM> for supplying power to the speaker <NUM>, and the power supply circuit <NUM> includes the power supply coil <NUM> wound around the first relay magnetic body <NUM>-<NUM>, and the sound output module <NUM> that corresponds to a load to perform a function based on the supplied power.

In an embodiment of the disclosure, the power supply coil <NUM> may be wound in the same direction as the direction in which the relay coil <NUM> is wound around the first relay magnetic body <NUM>-<NUM>.

Specifically, the power supply coil <NUM> is wound around the first relay magnetic body <NUM>-<NUM> in a structure physically separated from the relay coil <NUM> wound around the first relay magnetic body <NUM>-<NUM>, and currents flowing in the relay coil <NUM> and the power supply coil <NUM> are in phase.

As described above, a passive device including only L and C with the power supply coil <NUM> provided on the first relay magnetic body <NUM>-<NUM> is used to supply power to the speaker <NUM>, thereby reducing power loss and eliminating the need for additional circuit installation.

<FIG> is a block diagram of a wireless power relaying device and a display system, according to another embodiment of the disclosure, and <FIG> is a circuit diagram of a wireless power relaying device and a display system, according to another embodiment of the disclosure.

Referring to <FIG>, the display <NUM> of the display system <NUM> may include the image output module <NUM> and the display magnetic body <NUM>, around which the display coil <NUM> may be wound.

As shown in <FIG>, unlike in <FIG>, the display magnetic body <NUM> is in the singular, and the display coil <NUM> may be wound around the single display magnetic body <NUM>.

The speaker <NUM> of the display system <NUM> may be implemented as a wireless power relaying device. In the embodiment of the disclosure, the speaker <NUM> may include a relay magnetic body <NUM>, around which the relay coil <NUM> may be wound.

The speaker <NUM> may also include the sound output module <NUM> that performs a function of the speaker <NUM> based on the received power.

The relay magnetic body <NUM> of <FIG> may be implemented as an integrated relay magnetic body <NUM> rather than separated magnetic bodies as shown in <FIG>. In the embodiment of the disclosure, for simplicity in manufacturing and design, the relay magnetic body <NUM> included in the speaker <NUM> may be implemented in a single body without dividing it into three.

As shown in <FIG>, the relay magnetic body <NUM> may be provided in a single integrated body, and the relay coil <NUM> may be wound around the relay magnetic body <NUM> at predefined positions. For example, the relay coil <NUM> may be wound on the center and both ends of the relay magnetic body <NUM>.

The relay coil <NUM> wound on the center of the relay magnetic body <NUM> and the relay coil <NUM> wound on the either end of the relay magnetic body <NUM> may be separated from each other by a predefined distance.

The relay coils <NUM> wound at the predefined positions may be connected in series to each other.

As shown in <FIG>, a direction in which the relay coil <NUM> is wound on the center of the relay magnetic body <NUM> and a direction in which the relay coil <NUM> is wound on either end of the relay magnetic body <NUM> are different. The directions in which the relay coils <NUM> are wound on both ends of the relay magnetic body <NUM> are the same.

As the relay coil <NUM> wound on the center of the relay magnetic body <NUM> and the relay coil <NUM> wound on the either end of the relay magnetic body <NUM> have different winding directions, a leaked magnetic field may be canceled out, thereby reducing EMI.

The speaker <NUM> further includes the power supply circuit <NUM> for supplying power to the speaker <NUM>, and the power supply circuit <NUM> includes the power supply coil <NUM> wound around a power supply magnetic body <NUM> arranged separately from the relay magnetic body <NUM>, and the sound output module <NUM> that corresponds to a load to perform a function based on the supplied power.

As described above in connection with <FIG>, the power supply coil <NUM> is wound around the first relay magnetic body <NUM>-<NUM>, but in this embodiment of the disclosure as shown in <FIG>, the power supply coil <NUM> is wound around the power supply magnetic body <NUM>.

Furthermore, as shown in <FIG>, a thread of the relay coil <NUM> wound on the center of the relay magnetic body <NUM> is also wound around the power supply magnetic body <NUM>.

As such, the power supply magnetic body <NUM> may be implemented in a toroidal type, where some of the relay coil <NUM> wound on the center of the relay magnetic body <NUM> is wound around the power supply magnetic body <NUM> and the power supply coil <NUM> is wound around the power supply magnetic body <NUM> to send power to the sound output module <NUM>.

Supplying power to the speaker <NUM> through the power supply coil <NUM> separately provided on the power supply magnetic body <NUM> of the toroidal type may reduce power loss and eliminate the need for additional circuit installation.

In an embodiment of the disclosure, the wireless power transmitter <NUM> may transmit the first power signal <NUM> to the speaker <NUM> by converting the power supplied from the external power source <NUM> to the first magnetic field <NUM>.

The relay coil <NUM> provided on the relay magnetic body <NUM> of the speaker <NUM> may produce the second magnetic field <NUM> by a first current induced from the first magnetic field <NUM> produced from the wireless power transmitter <NUM>.

The display coil <NUM> provided on the display magnetic body <NUM> of the display <NUM> may produce the third magnetic field <NUM> by the second current induced from the second magnetic field <NUM> produced from the speaker <NUM>.

Referring to <FIG>, when AC power is applied to the wireless power transmitter <NUM> from the power source <NUM>, the first magnetic field <NUM> is produced on and around the power transmit magnetic body <NUM> due to the current flowing in the power transmit coil <NUM>.

Specifically, the first magnetic field <NUM> produced from the power transmit magnetic body <NUM> causes the induced current to flow in the relay coil <NUM> of the speaker <NUM>, and the second magnetic field <NUM> is produced on and around the relay magnetic body <NUM> according to Lenz's law about the direction of electromagnetic induction.

As shown in <FIG>, the first magnetic field <NUM> induces the first current in the entire relay coils <NUM> provided on the relay magnetic body <NUM> of the speaker <NUM>, and the first current produces the second magnetic field <NUM> around the relay magnetic body <NUM>.

As shown in <FIG>, the second magnetic field <NUM> from the relay coil <NUM> provided on the center of the relay magnetic body <NUM> induces the second current in the display coil <NUM> provided on the display magnetic body <NUM> of the display <NUM>, and the second current produces the third magnetic field <NUM> around the display magnetic body <NUM>.

The wireless power transmission procedure in the display system <NUM> according to the embodiment of the disclosure as shown in <FIG> is the same as that in the previous embodiment of the disclosure as shown in <FIG>, so the description thereof will not be repeated.

Similar to what are described above in connection with <FIG> and <FIG>, in <FIG>, as there is a phase difference of <NUM> ° between the first magnetic field <NUM> produced from the wireless power transmitter <NUM> and the third magnetic field <NUM> produced from the display <NUM>, a leaked magnetic field caused from the first magnetic field <NUM> is canceled out by the third magnetic field <NUM>, thereby reducing EMI created from the first magnetic field <NUM>.

In the meantime, although the leaked magnetic field may be reduced in the aforementioned method by locating the speaker <NUM> between the wireless power transmitter <NUM> and the display <NUM>, a leaked magnetic field may be caused due to the second magnetic field <NUM> produced from the center of the relay magnetic body <NUM> provided in the speaker <NUM>.

To reduce EMI due to the leaked magnetic field caused from the speaker <NUM>, the leaked magnetic field may be canceled out by winding the relay coil <NUM> around the relay magnetic body <NUM> of the speaker <NUM> on either side of the relay coil <NUM> wound on the center at a predefined distance in a predefined direction.

In the embodiment as shown in <FIG>, unlike the previous embodiment of <FIG>, the relay magnetic body <NUM> of the speaker <NUM> is provided in a single integrated body rather than being divided into three.

The relay magnetic body <NUM> is implemented in a single body, but is wound by the relay coils <NUM> at the center in one direction and at either end in the other direction, so that a leaked magnetic field caused from the second magnetic field <NUM> produced from the center of the relay magnetic body <NUM> may be canceled out by the second magnetic field <NUM> produced from the both ends of the relay magnetic body <NUM>, thereby reducing EMI.

It is also possible for the relay coils <NUM> to be wound on the center of the relay magnetic body <NUM> and on either end of the relay magnetic body <NUM> in the opposite directions to what are shown in <FIG>.

The speaker <NUM> further includes the power supply circuit <NUM> for supplying power to the speaker <NUM>, and the power supply circuit <NUM> includes the power supply coil <NUM> wound around the power supply magnetic body <NUM> arranged separately from the relay magnetic body <NUM>, and the sound output module <NUM> that corresponds to a load to perform a function using the supplied power.

The power supply coil <NUM> is wound around the power supply magnetic body <NUM>, and a thread of the relay coil <NUM> wound on the center of the relay magnetic body <NUM> is also wound around the power supply magnetic body <NUM> of the toroidal type. The power supply coil <NUM> may be wound around the power supply magnetic body <NUM> to send power to the sound output module <NUM>.

When the relay magnetic body <NUM> included in the speaker <NUM> is implemented in a single magnetic body, an extra toroidal magnetic body for sending power to the sound output module <NUM> may be used to distribute power through impedance conversion not to interfere with the current flowing in the relay coil <NUM>.

The impedance conversion is made based on the number of turns of the relay coil <NUM> wound around the toroidal type of power supply magnetic body <NUM> and the number of turns of the power supply coil <NUM> connected to the sound output module <NUM>.

In the embodiment of the disclosure, supplying power to the speaker <NUM> through the power supply coil <NUM> separately provided on the power supply magnetic body <NUM> of the toroidal type may reduce power loss and eliminate the need for additional circuit installation.

<FIG> shows second and third relay magnetic bodies implemented to have different thickness from that of a first relay magnetic body, according to an embodiment of the disclosure.

Referring to <FIG>, in the speaker <NUM>, the second and third relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM> located on either side of the first relay magnetic body <NUM>-<NUM> may be thinner than the first relay magnetic body <NUM>-<NUM>.

Based on the nature of a coil wound around a magnetic body, an internal magnetic field is intense at the center of the magnetic body and gets weaker the father to the left and right of the magnetic body. Hence, the second relay magnetic body <NUM>-<NUM> arranged on the left of the first relay magnetic body <NUM>-<NUM> and the third relay magnetic body <NUM>-<NUM> arranged on the right of the first relay magnetic body <NUM>-<NUM> may have the same thickness as the first relay magnetic body <NUM>-<NUM> or may be as thin as predefined thickness.

For example, when the second and third relay magnetic bodies <NUM>-<NUM> and <NUM>-<NUM> have half the thickness of the first relay magnetic body <NUM>-<NUM>, the weight of the speaker <NUM> may be reduced.

Thicknesses of the first to third relay magnetic bodies <NUM>-<NUM> to <NUM>-<NUM> may be set to predefined values.

Meanwhile, the embodiments of the disclosure may be implemented in the form of recording media for storing instructions to be carried out by a computer. The instructions may be stored in the form of program codes, and when executed by a processor, may generate program modules to perform operation in the embodiments of the disclosure. The recording media may correspond to computer-readable recording media.

The computer-readable recording medium includes any type of recording medium having data stored thereon that may be thereafter read by a computer. For example, it may be a ROM, a RAM, a magnetic tape, a magnetic disk, a flash memory, an optical data storage device, etc..

Claim 1:
A wireless power relaying device comprising:
first, second, and third magnetic bodies (<NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>) arranged so that the first magnetic body (<NUM>-<NUM>) is between the second magnetic body (<NUM>-<NUM>) and the third magnetic body (<NUM>-<NUM>), and a distance between the first magnetic body (<NUM>-<NUM>) and the second magnet body (<NUM>-<NUM>) is the same as a distance between the first magnetic body (<NUM>-<NUM>) and the third magnetic body (<NUM>-<NUM>),
first, second and third relay coils (<NUM>) wound around the first, second and third magnetic bodies (<NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>), respectively, wherein the first relay coil (<NUM>-<NUM>), the second relay coil (<NUM>-<NUM>) and the third relay coil (<NUM>-<NUM>) are connected in series and wherein
a direction in which the first relay coil (<NUM>) is wound around the first magnetic body (<NUM>-<NUM>) is different from a direction in which the second relay coil (<NUM>) is wound around the second magnetic body (<NUM>-<NUM>) and a direction in which the third relay coil (<NUM>) is wound around the third magnetic body (<NUM>-<NUM>),
the direction in which the second relay coil (<NUM>) is wound around the second magnetic body (<NUM>-<NUM>) is the same as the direction in which the third relay coil (<NUM>) is wound around the third magnetic body (<NUM>-<NUM>), and
the first, second, and third magnetic bodies (<NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>), and the first, second and third relay coils (<NUM>), are thereby configured so that a current is inducible in the first, second and third relay coils (<NUM>) by a first magnetic field (<NUM>) from a first external device, and the induced current causes a second magnet field (<NUM>) to be produced by the first, second and third relay coils (<NUM>) through which a power signal is transmittable to a second external device;
characterized in that the wireless power relaying device further comprises:
a power supply circuit (<NUM>) configured to supply power to the wireless power relaying device; and
a load module (<NUM>) configured to perform a function using the supplied power;
wherein the power supply circuit (<NUM>) comprises a power supply coil (<NUM>) arranged on the first magnetic body (<NUM>-<NUM>), and
wherein the power supply coil (<NUM>) is wound in the same direction as the first relay coil (<NUM>) is wound around the first magnetic body (<NUM>-<NUM>).