KR20200040217A - Wireless power transmission device enhencing visibility of charging state, amd furniture having charging function by installing the same - Google Patents

Abstract

The present invention relates to a wireless power transmission device increasing visibility of a charging state, and furniture having a wireless charging function mounting the same. The wireless power transmission device increasing visibility of the charging state comprises: a transmission block including a primary coil for transmitting a wireless power signal; a light emitting unit displaying whether or not wireless charging is performed; a light guide unit propagating light from the light emitting unit; and a transmission control unit controlling the transmission block to transmit the wireless power signal to a wireless power reception device, and controlling the light emitting unit based on charging state information from the wireless power reception device.

Description

Wireless power transmission device with increased visibility in charging state and furniture equipped with wireless charging function equipped with the same

The present invention relates to a wireless power transmission device having improved visibility in a charged state, and furniture equipped with a wireless charging function equipped with the same.

Generally, a battery pack is used to supply power (electrical energy) from an external charger and to supply power for the operation of a portable terminal (cell phone, PDA, etc.) in a charged state. A circuit for charging and discharging a cell and the battery cell (supplying electric energy to a portable terminal) is constructed.

In the electric connection method of the charger and the battery pack for charging the electric energy to the battery pack used in such a portable terminal. There is a terminal supply method that receives commercial power and converts it into voltage and current corresponding to the battery pack to supply electrical energy to the battery pack through the terminals of the battery pack.

However, when power is supplied through the terminal supply method, when the charger and the battery pack are contacted or disconnected, the terminals on both sides (the terminal of the battery pack and the terminal of the charger) have different potential differences, resulting in an instantaneous discharge phenomenon. There was a problem.

Particularly, due to the instantaneous discharge phenomenon, there is a fear that a fire may occur when foreign substances are accumulated on the terminals on both sides.

In addition, there is a problem in that electric energy charged in the battery pack due to moisture is naturally discharged to the outside through the terminal of the battery pack, and of course, there is a disadvantage that deteriorates the life and performance of the battery pack.

Recently, in order to solve the above problems, a charging system and a control method of a contactless method using a wireless power transmission method have been proposed.

There have been attempts to apply such a contactless charging system to smartphones, tablet PCs, etc., which require frequent charging, because the user does not need to combine gender for charging. Recently, in the case of a smartphone equipped with various apps, users have the inconvenience of carrying a separate charging battery (external battery) due to the need for frequent battery charging.

Accordingly, when the user does not use the smartphone even for a moment, there is a need to prevent discharge of the smartphone through a brief charging.

Accordingly, when a wireless power transmission device (wireless charger) is attached to a flat-type furniture such as a table, and the user sits in front of the table to work or eat, his smart phone (wireless power receiving device) is charged at the table You can start charging by putting it on.

As described above, when the wireless power transmission device is installed in the furniture, the wireless power charging device should be disposed on the bottom surface to protect the exterior of the furniture. In this case, it was difficult to indicate the charging position or the charging status on the table.

The present invention has been devised to solve the above-mentioned problems, as well as clearly displaying the charging position, and can visually confirm whether the charging is well performed, and equipped with a wireless power transmission device having improved visibility of the charging state and the same It is intended to provide furniture with a wireless charging function.

An embodiment of the present invention devised to solve the above-described problem, a wireless power transmission device with improved visibility of a charging state, a transmission block including a primary coil for transmitting a wireless power signal; A light emitting unit for displaying wireless charging or not; A light guide unit for propagating light from the light emitting unit; And a transmission control unit controlling the transmission block, transmitting a wireless power signal to the wireless power receiving device, and controlling the light emitting unit based on charging state information from the wireless power receiving device.

Here, the wireless power transmission device having increased visibility of the charging state further includes a temperature sensor, and the transmission control unit, if the temperature measured from the temperature sensor while the wireless power signal is simultaneously transmitted is greater than or equal to a reference value, the wireless power transmission device It is possible to limit the transmission of all power signals.

Here, the light guide portion may be an optical fiber.

Here, the light emitting unit may include a first light emitting module for displaying normal charging and a second light emitting module for displaying charging failure.

Here, the optical fiber may include a branch part that connects the first light emitting module and the second light emitting module, respectively.

Here, the optical fiber may be embedded so that light is irradiated from the surface of the flat-type furniture to the outside.

Here, the transmission block includes: an object detection unit for transmitting a response signal generated according to the wireless power receiving apparatus from the primary coil to the transmission control unit; A converter connected to the primary coil; And when the wireless power receiving device is detected by the object detection unit under the control of the transmission control unit may include a driving driver for sending a drive signal to the converter.

In another embodiment of the present invention, the wireless charging flat type furniture includes a wireless power transmission device attached to a bottom surface of the flat panel of the flat type furniture, and the wireless power transmission device is a primary for transmitting a wireless power signal. A transmission block comprising a coil; A light emitting unit for displaying wireless charging or not; A light guide portion that propagates light from the light emitting portion and is embedded in a main surface of the flat plate portion so that the light can be irradiated to the outside; And a transmission control unit controlling the transmission block, transmitting a wireless power signal to the wireless power receiving device, and controlling the light emitting unit based on charging state information from the wireless power receiving device.

Here, the light guide portion may be an optical fiber.

Here, the light guide unit may be buried in a position corresponding to the primary coil so that the charging position can be displayed.

Here, the light emitting unit may include a first light emitting module for displaying normal charging and a second light emitting module for displaying charging failure.

Here, the optical fiber may include a branch part that connects the first light emitting module and the second light emitting module, respectively.

Here, the wirelessly chargeable furniture may further include a transparent protective coating layer to coat the main surface of the flat plate portion to protect the light guide portion.

According to an embodiment of the present invention having the above-described configuration, the light irradiated through the light emitting unit propagates through the light guide unit, and the user can check the charging state through the light guide unit, so that the charging state in the wireless power transmission system is visible. It can be confirmed highly.

Moreover, by using the light guide portion to indicate the charging position, visibility to the charging position is increased. In addition, when such a wireless power transmission device is used in a flat-type furniture such as a table, the light guide portion is embedded in the flat panel of the furniture, thereby facilitating confirmation of a charging position and increasing visibility of a charging state.

1 is a perspective view for explaining an external appearance of a wireless power transmission device with improved visibility in a charged state, which is an embodiment of the present invention, and FIG. 1B is a view for explaining a light emitting unit and a light guide unit in FIG. 1A.
FIG. 2 is a block diagram for explaining an electronic configuration of a wireless power transmission system including a wireless power transmission device with improved visibility in a charging state, which is an embodiment of the present invention.
Figure 3 is a view for explaining the appearance of a furniture equipped with a wireless charging function equipped with a wireless power transmission device to increase the visibility of the charging state that is an embodiment of the present invention.
4 is a cross-sectional view for explaining a state in which a wireless power transmission device with improved visibility of a charged state, which is an embodiment of the present invention, is installed on a flat plate of a table.
5 is a flow chart illustrating a method for performing foreign object detection in a wireless power transmission system including a wireless power transmission device with improved visibility of a charged state according to an embodiment of the present invention.
6 is a flow chart showing a method of performing foreign material detection in a wireless power transmission system including a wireless power transmission device with improved visibility of a charged state according to another embodiment of the present invention.
7 is a flow chart illustrating a method of performing foreign material detection in a wireless power transmission system including a wireless power transmission device with improved visibility of a charged state according to another embodiment of the present invention.
8 is a flowchart illustrating a method of performing foreign material detection in a wireless power transmission system including a wireless power transmission device with improved visibility of a charging state according to an embodiment of the present invention.
9 is a flowchart of an operation in a wireless power transmission system including a wireless power transmission device with improved visibility of a charged state according to another embodiment of the present invention.
10 is a flowchart of an operation of a wireless power transmission system including a wireless power transmission device with improved visibility of a charged state according to another embodiment of the present invention.

The suffixes "modules" and "parts" for the components used in the following description are given or mixed only considering the ease of writing the specification, and do not have meanings or roles distinguished from each other in themselves.

Hereinafter, an example of a dining table is illustrated as a representative example of furniture equipped with a wireless charging function. It should be understood that the present invention is not limited to this, and can be applied to furniture having a flat plate to place a plurality of smartphones such as an office table, a dresser, a table, and a shelf.

1 is a perspective view for explaining an external appearance of a wireless power transmission device with improved visibility in a charged state, which is an embodiment of the present invention, and FIG. 1B is a view for explaining a light emitting unit and a light guide unit in FIG. 1A. As shown in Figure 1a, when the wireless power transmission device 100, which is an embodiment of the present invention is installed on the bottom surface of the table 300, the wireless power receiving device 200 in the charging position formed on the flat plate of the table 300 : For example, a smartphone) can be placed. When the wireless power receiving device 200 is placed in the charging position, the wireless power transmitting device 100 oscillates the wireless power signal to wirelessly supply power to the wireless power receiving device 200. At this time, in order to display the wireless power transmission state, the light emitting unit 120 may be installed at one end of the main surface of the wireless power transmission device 100.

The light guide portion 130 is connected to the light emitting portion, and the light guide portion 130 made of optical fiber is drawn out to the upper surface of the table 300 through a fine through hole pre-installed on the table. Accordingly, the light guide unit 130 is located on the upper surface of the table 300, and the charging state can be known by the color change of the light guide unit 130.

1B is a detailed drawing of the light emitting unit. As illustrated in FIG. 1B, the light emitting unit 120 includes a first light emitting module 121 for displaying a normal state (for example, a module emitting green light) and a second light emitting module for displaying charging failure ( 122) (eg, a module emitting red light) and a cap 123 covering the first light emitting module 121 and the second light emitting module 122 to protect them. The cap 123 not only protects the first light emitting module 121 and the second light emitting module 122, but also does not expose the light irradiated from the light emitting modules to the outside, and guides them all to the light guide 130 It does the function to do.

Although an example in which each light emitting module 121 and 122 emit different colors has been described, the present invention is not limited thereto, and a charging state may be displayed through various colors in one light emitting module.

Meanwhile, the optical fiber 130 as a light guide portion may be connected to the light emitting portion 120 to be extended. That is, the optical fiber 130 includes a branch portion 131, which is attached to the first light emitting module 121 and the second light emitting module 122, respectively. The branch 131 is positioned inside the cap 123. The light guide unit 130 functions to propagate light irradiated from the light emitting unit 120. In the present invention, the light guide unit 130 is buried on the table, so that the user can use his smartphone 200 on the table. When charging by placing the charging position, it is possible to check the state of charge of the smartphone 200 through light irradiated from the light guide unit 130. This will be described in more detail in FIGS. 3 and 4.

Hereinafter, an electronic configuration of a wireless power transmission system including a wireless power transmission device having increased visibility in a charged state with increased visibility in a charged state having the above-described appearance will be described in more detail with reference to FIG. 2.

2 is a block diagram for explaining an electronic configuration of a wireless power transmission system including a wireless power transmission device with improved visibility in a charged state, which is an embodiment of the present invention.

As shown in FIG. 2, the wireless power transmission system may include a wireless power transmission device 100 and a wireless power reception device 200.

The wireless power transmission apparatus 100 according to the present invention may include a transmission block 110, a light emitting unit 120, a light guide unit 130, a temperature sensor 140, and a transmission control unit 150.

Here, since the light emitting unit 120 and the light guide unit are described in FIG. 1, a description thereof will be omitted.

The transmission block, as shown in Figure 2, the primary coil 111, the primary coil 111 is connected to the converter 115, the converter 115 is connected to the drive driver 117, and the primary It may be connected to the coil 111, the wireless power receiving device 200 may include an object detection unit 113 for detecting whether the charging position.

The primary coil 111 is a component that oscillates the wireless power signal, and oscillates the wireless power signal to the wireless power receiving device 200 by an electromagnetic induction method. The primary coil 111 may have a circular shape, an oval shape, a track shape, a square shape, a polygonal shape, or the like.

Although the case in which the primary coil 111 is one is described in the transmission block 110 in the present invention, the present invention is not limited thereto, and the primary coil 111 may be installed in pairs.

The converter 115 generates transmission power for generating a power signal to be transmitted by the control of the driving driver 117 and supplies it to the primary coil 111. In other words, when the wireless power receiving device 200 is placed at the charging position, the transmission control unit 150 drives the power control signal that causes the converter 115 to transmit a power signal having a required power value. And the driving driver 117 controls the operation of the converter 115 by the transmitted power control signal. Accordingly, the converter 115 applies the transmitted power corresponding to the power value required by the control of the driving driver 117 to the corresponding primary coil 111, so that the wireless power signal of the required strength is charged in the charging position. It is to be transmitted to the wireless power receiving device 200 in the.

The driving driver 117 controls the operation of the converter 115 through the control of the transmission control unit 150.

The object detection unit 113 detects a load change of the primary coil 111, detects whether there is an object at a charging position, and accordingly, the transmission control unit 150 transmits a digital ping signal to the driving driver 117 ) Is controlled to oscillate through the transmission coil, and a signal strength packet signal is received from the wireless power receiving device 200 as a response signal to determine whether the object is caused by the wireless power receiving device 200. (In other words, it has a function as an ID verification unit), and performs a function of filtering and processing charging state information transmitted from the wireless power receiving device 200. That is, when an object response signal, which is a signal strength packet signal for digital ping of an object detection signal transmitted through the primary coil 111, and a signal including charging state information are received, functions to filter and process them.

The transmission control unit 150 receives and confirms the determination result of the object detection unit 113, analyzes the object response signal received from the primary coil 111, and wireless power through the primary coil 111. It serves to transmit the power signal for transmitting the signal to the driving driver 117. Meanwhile, the transmission control unit 150 controls the light emitting unit 120 based on charging state information from the wireless power receiving device. That is, when it is determined that the wireless power receiving device is normally charged, the first light emitting module 121 is controlled to control green light to be emitted, so that the green light is propagated to the light guide unit 130. If it is determined that the wireless power receiving apparatus 200 is not normally charged, the second light emitting module 122 is controlled to control red light emission so that the red light propagates to the light guide 130.

By operating in this way, it is possible to know the state of charge through the light emission color of the optical fiber 130. As described above, the light guide unit 130 may be made of optical fiber, and the optical fiber may be buried so that light is irradiated from the surface of the flat-type furniture to the outside. This will be described in more detail in FIGS. 3 and 4.

Meanwhile, the temperature sensor 140 functions to detect that the wireless power transmission apparatus 100 is overheated due to foreign matter. When a foreign material such as a coin is located at a charging position of the wireless power transmission apparatus 100 during or during wireless charging, wireless power transmission is not normally performed, and accordingly, power waste occurs, resulting in wireless power. The transmission device 100 becomes overheated.

In the present invention, if the temperature measured by the temperature sensor 140 is greater than or equal to a reference value while the wireless power signal is simultaneously transmitted, the transmission control unit 150 functions to limit the transmission of the wireless power signal. Accordingly, it is possible to prevent power from being wasted abnormally.

Meanwhile, although not shown in the drawings, the sound output module may be further included. Accordingly, the transmission control unit 150 may control to output the state of whether normal charging or abnormal charging is performed through the sound output module. That is, in the case of normal charging, after a certain time (for example, 3 seconds) of a beep indicating the normal charging state is output, the beeping sound is no longer output. If the charging is abnormal, a beeping sound indicating the abnormal state is continuously output. The sound output module can be controlled as much as possible.

Meanwhile, the wireless power receiving device 200 receiving the power signal and receiving the power includes a secondary coil 210 for generating induced power by the transmitted power signal, and a rectifying unit 220 for rectifying the induced power And a battery 230 charged with rectified power and a reception control unit 240.

Here, the battery cell module 230 is configured to include a protection circuit such as an overvoltage and overcurrent prevention circuit, a temperature sensing circuit, and also includes a charging management module that collects and processes information such as the charging state of the battery cell. .

Hereinafter, a furniture equipped with a wireless power transmission device having increased visibility in a charged state having the above-described configuration will be described in more detail with reference to FIGS. 3 and 4.

FIG. 3 is a view for explaining the appearance of a furniture equipped with a wireless charging function equipped with a wireless power transmission device with improved visibility in a charging state, which is an embodiment of the present invention. As shown in the drawing, the wireless power transmission device 100 having improved visibility in the charging state described in FIGS. 1 and 2 may be attached to the bottom surface of the flat panel 310 of a flat-type furniture such as a table 300. In addition, the optical fiber 130 extending from one end of the wireless power transmission apparatus 100 is exposed to the upper portion through a hole in the flat plate portion 310, and may be located in a buried groove formed in the upper portion. The buried groove may be formed at a position corresponding to the position of the primary coil 111. Accordingly, when an external power is supplied to the wireless power transmission apparatus 100, the light emitting unit 120 emits light, and the optical fiber 130 partially exposed on the upper portion of the flat panel 310 emits light. , The user can check the charging position.

Then, when the user positions his / her smartphone (wireless power receiving device) 200 in the charging position, charging is started. When the charging is normally charged, the transmission control unit 150 controls the light emitting unit 120 so that the green light is emitted, so that the user can know that the optical fiber 130 is shining in green, so that the charging is normally performed. Conversely, if charging is not normally performed, the transmission control unit 150 controls the light emitting unit 120 so that the red light is emitted, so that the user can confirm that the optical fiber 130 is glowing red. Accordingly, the user can know that charging is not currently performed.

In FIG. 4, the installation state of the wireless power transmission device and the optical fiber will be described through a cross-sectional view of the table.

4 is a cross-sectional view for explaining a state in which a wireless power transmission device with improved visibility in a charged state, which is an embodiment of the present invention, is installed on a flat plate of a table. As shown, a mounting groove for mounting the wireless power transmission device 100 is formed on the bottom surface of the flat plate 310 of the table 300, and the wireless power transmission device 100 is inserted into the wireless power transmission device. 100 is installed. On the other hand, the optical fiber 130 is formed extending from the wireless power transmission device 100, is drawn through a micro-through hole formed perpendicular to the plate, it may be installed to be partially exposed on the upper surface of the plate. That is, a micro-through hole is formed at a position corresponding to the light emitting part 120 of the flat plate 310, so that the optical fiber 130 is drawn out to the upper surface of the flat plate 310 through the micro-through hole, and then charged In order to indicate the position, the optical fiber 130 is disposed at a position corresponding to the position of the primary coil 111. Accordingly, the user can check the light of the optical fiber 130.

Meanwhile, a transparent coating layer 311 may be further applied to the upper surface of the flat plate. The optical fiber and the flat plate 310 may be protected by the transparent coating layer 311.

Hereinafter, a method for detecting a foreign object in a wireless power transmission system including a wireless power transmission device having increased visibility of a charged state having the above-described configuration will be described with reference to FIGS. 5 to 10.

5 is a flowchart illustrating a method of performing foreign object detection in a wireless power transmission system including a wireless power transmission device capable of simultaneous multi-charging according to an embodiment of the present invention.

Referring to FIG. 5, a foreign object detection operation is performed before initial charging (S200). For example, the operation of detecting a foreign substance before the initial charging is as follows.

When a foreign object is detected before the initial charging (S205), a power limiting operation corresponding to the foreign material detection is performed (S225).

When a foreign object is not detected before the initial charging (S205), when charging starts, a foreign matter detection operation is performed during charging (S210).

For example, a foreign object may be detected by performing a one-way communication during charging. For example, the operation of detecting a foreign object using unidirectional communication during charging is as follows.

As another example, a foreign object may be detected by performing bidirectional communication during charging. For example, the operation of detecting a foreign object using bidirectional communication during charging is as follows.

As another example, foreign substances may be detected by simultaneously or independently performing the one-way communication and the two-way communication during charging.

When a foreign material is detected during charging (S215), the power limitation operation corresponding to the foreign material detection is performed as in step S225.

When a foreign object is not detected during charging (S215), when a problem occurs in power transmission with a small foreign object that is not detected, power is limited based on the temperature sensor 130 (or thermistor) to protect the power transmission (eg, Cut off the power) (S220). The temperature sensor may be attached to the receiving device or to the transmitting device.

Alternatively, even after the power limitation operation corresponding to the detection of a foreign substance is performed in step S225, if a problem occurs in the power transmission with a fine foreign matter that is not detected, the power is limited based on a temperature sensor (or thermistor) to protect the power transmission.

6 is a flowchart illustrating a method of performing foreign material detection in a wireless power transmission system including a wireless power transmission device with improved visibility of a charged state according to another embodiment of the present invention.

Referring to FIG. 6, a foreign object detection operation is performed before initial charging (S300).

When a foreign object is detected before the initial charging (S305), a power limiting operation corresponding to the foreign material detection is performed (S315).

When a foreign object is not detected before the first charge (S305), if there is a problem in power transmission due to a small foreign object that is not detected, power is limited based on a temperature sensor (or thermistor) to protect the power transmission (eg, power) (S310). The temperature sensor may be attached to the receiving device or to the transmitting device.

Alternatively, even after the power limiting operation corresponding to the detection of a foreign substance is performed in step S315, when a problem occurs in power transmission with a fine foreign object that is not detected, power is limited based on a temperature sensor (or thermistor) to protect the power transmission.

7 is a flowchart illustrating a method of performing foreign object detection in a wireless power transmission system in a wireless power transmission system including a wireless power transmission device with improved visibility of a charging state according to another embodiment of the present invention.

Referring to FIG. 7, when charging starts, a foreign object detection operation is performed during charging (S400).

When a foreign material is detected during charging (S405), a power limiting operation corresponding to the foreign material detection is performed (S415).

When a foreign object is not detected during charging (S405), if there is a problem in power transmission due to a small foreign object that is not detected, power is limited based on a temperature sensor (or thermistor) to protect the power transmission (eg, cut off power) ) (S410). The temperature sensor may be attached to the receiving device or to the transmitting device.

Alternatively, even after the power limitation operation corresponding to the detection of a foreign substance is performed in step S415, when a problem occurs in the power transmission with a fine foreign matter that is not detected, power is limited based on a temperature sensor (or thermistor) to protect the power transmission.

Now, according to the present invention, the operation of detecting a foreign material will be described separately before and after the initial charging (eg, using one-way communication or using two-way communication).

One. Foreign object detection operation before initial charging

8 is a flowchart illustrating a method of performing foreign material detection in a wireless power transmission system including a wireless power transmission device with improved visibility of a charging state according to an embodiment of the present invention. Corresponds to step S200 of FIG. 2 or step S300 of FIG. 3.

Referring to FIG. 8, in the ping phase, the wireless power transmission device performs digital ping, wherein the wireless power transmission device transmits the power signal of the operating point to the wireless power reception device (S500).

When the Ping Phase power signal is received, the wireless power reception device generates a signal strength packet indicating the strength of the received power signal and transmits the signal strength packet to the wireless power transmission device (S505). Then, the wireless power receiving device generates an identification packet indicating the unique ID of the wireless power receiving device and configuration information of the wireless power receiving device, and transmits the identification packet and the configuration information to the wireless power transmission device (S510).

The wireless power receiving device measures the received power (S515). From this point, the step of setting the initial voltage V _i is entered.

The wireless power receiving device determines whether a reason for termination such as over voltage power (OVP), over current power (OCP), full charge occurs (S520). If an OVP, OCP, full charge, or other reason for the type of charging occurs, the wireless power receiving device ends charging (S525). If the reason for the type does not occur, the wireless power receiving device determines whether it is in the state of receiving wireless power from the wireless power transmitting device, that is, charging (S530).

In step S530, if charging, the wireless power receiving device compares the received power against the required power, generates a power control packet based on the result, and transmits it to the wireless power transmitting device (S535). In step S535, if it is not being charged, the wireless power receiver determines whether the initial voltage V _i is in a hold state (S540). When the value of the steady state of the initial voltage V _i is within the reference voltage range (for example, 7.0 V to 10.5 V), the wireless power receiving device is initially set. As a result, the initial voltage V _i is in a hold state, and the wireless power receiver can enter the foreign material detection phase.

If not in the V _i hold state, the wireless power receiving device generates a power control packet and transmits it to the wireless power transmitting device as in the case of charging (S535). If V _{i is in the} hold state, the wireless power receiving device enters the foreign material detection phase. Here, the wireless power receiving device generates a foreign object status packet and transmits it to the wireless power transmitting device (S545).

The foreign object status packet according to the present invention includes a preamble, a header, a message, and a checksum. The preamble may be composed of a minimum of 11 bits and a maximum of 25 bits, and values of all bits may be set to 0. The preamble is used by the wireless power transmitter to accurately detect the start bit of the header of the foreign object status packet and synchronize the incoming data.

The header indicates the type of packet, and may be composed of 8 bits. As an example, the value of the header of the foreign object status packet may be '0x00'. In this case, the message may be set to 0, that is, '0x00'. As another example, the value of the header of the foreign matter status packet may be '0x05' which is the same as the header of the charge status packet. However, since the value of the 1-byte message of the charge status packet is set to '0x00', it may be indicated that it is a foreign matter status packet. That is, the foreign matter status packet is included in the charge status packet.

The wireless power transmission apparatus checks whether the received packet is a foreign object status packet based on the header of the received packet or the value of the message. Then, when it is determined that the foreign matter status packet has been received, the wireless power transmission apparatus performs foreign matter detection (S550). The operation of checking the foreign matter status packet and foreign matter detection are performed by the control unit of the wireless power transmission apparatus.

2. Foreign object detection during charging

2-1. Foreign object detection using unidirectional communication during charging

9 is a flowchart of an operation of a wireless power transmission system including a wireless power transmission device with improved visibility of a charged state according to another embodiment of the present invention. Corresponds to step S210 of FIG. 2 or step S400 of FIG. 4.

Referring to FIG. 9, the wireless power transmission device searches for a wireless power reception device (S600). At this time, the wireless power transmission device is in the standby state for charging until the wireless power reception device is detected.

If the detected object is a wireless power receiving device, the wireless power transmitting device enters a charging mode and transmits wireless power to the wireless power receiving device (S605). In the charging mode, the wireless power transmission device applies electric power to the primary coil to generate an induced magnetic field or resonance.

The wireless power transmission device measures the current flowing in the primary coil, and the wireless power transmission device acquires the current measurement value from the current flowing in the primary coil (S610). The current measured by the wireless power transmission device may be an alternating current. The current measurement value may be converted into a DC value suitable for the control unit in the wireless power transmission apparatus to recognize. That is, the wireless power transmission device measures a relatively high alternating current flowing in the primary coil, and maps the measured high current to a current measurement value that is a value suitable for the control unit to interpret as shown in Table 1.

Rx power
(unit: W) Tx AC current
(unit: A) Max AC current
(unit: A) 2.5 0.998 1.05 3 1.328 1.5 4 1.664 1.85 5 1.925 2.05

The wireless power transmission apparatus performs foreign matter detection using any one or a combination of two or more of parameters such as a reference current I _ref , a reference range (I _low ~ I _high ), a reference AC signal, and a foreign substance detection timing t (S615) ). In addition, parameters such as a reference current I _ref , a reference range (I _low to I _high ), a reference AC signal, and a foreign substance detection timing t may be stored in the wireless power transmission device as an initial setting value. The wireless power transmission device continuously transmits power to the wireless power reception device if no foreign matter is detected (S620). In addition, the wireless power transmission device acquires the current measurement value of the primary coil again at a predetermined time t by the system or the standard (S610), and may attempt to detect a foreign object based on this (S615).

On the other hand, the wireless power transmission device cuts off the wireless power transmitted to the wireless power receiving device when a foreign object is detected (S625).

2-2. Foreign object detection operation using two-way communication during charging

10 is a flowchart illustrating an operation of a wireless power transmission system including a wireless power transmission device with improved visibility of a charged state according to another embodiment of the present invention.

For example, performing bidirectional communication means that when power is transmitted from the transmitting device to the receiving device, the receiving device informs the transmitting device of the received power value, and if the power loss is greater than a predetermined reference value, it is determined as FOD. Say something. For example, performing two-way communication means that when the transmission device transmits 7 to 10W of power to the receiving device and receives 5W of power from the receiving device, the received power value '5W' is notified to the transmitting device, and the power loss is 2W. Since it is abnormal, it is greater than a predetermined reference value of 1W, so it is determined as FOD. Through this, it is possible to detect the FOD in the power transmission step.

When the two-way communication is described in detail with reference to FIG. 10, the wireless power transmission device searches for the wireless power reception device (S700). At this time, the wireless power transmission device is in the standby state for charging until the wireless power reception device is detected.

If the detected object is a wireless power receiving device, the wireless power transmitting device enters a charging mode and transmits wireless power to the wireless power receiving device (S705). In the charging mode, the wireless power transmission device applies electric power to the primary coil to generate an induced magnetic field or resonance.

The wireless power transmission device transmits a transmission power measurement report indicating the measured transmission power to the wireless power reception device (S710). For example, the wireless power transmission device transmits a transmission power measurement report to the wireless power reception device as an FSK signal. Here, the FSK signal refers to a signal transmitted using the FSK method.

The FSK signal may include a simple amount of power (eg, amount of transmit power). At this time, the wireless power transmission device may transmit the FSK signal at a constant cycle. This is because the wireless power receiving device may not know about the transmission timing of the FSK signal. The constant period may be a period in which a certain number of data signals are transmitted (eg, ASK signal is constant).

For example, the amount of transmission power may be a value measured by the wireless power transmission device in the main coil according to the AC current signal.

The FSK signal switches or selects a variable range of a variable frequency (eg, 140 or 140.3 Khz) that converts one fixed power frequency (f ₀ , eg 145 kHz) required by the receiving device. Thus, it means a signal that transmits 0 and 1 values. As another example, it refers to a signal that transmits a data signal including 0 and 1 values using a phase.

For example, the wireless power transmission device may measure the power generated by the main coil according to the AC current signal, configure a transmission power measurement report indicating the measured generated power, and transmit it to the wireless power reception device. As described above, control information is transmitted from a wireless power transmission device to a wireless power receiving device (for example, control information may be transmitted by an FSK signal), or from a wireless power receiving device to a wireless power transmission device. Two-way communication is possible through which control information is transmitted.

The wireless power transmission device performs PWM using an inverter, and generates a frequency allowed for required power (or required power) of the wireless power receiving device.

The required power of the wireless power receiving device generates a duty cycle or voltage, and the duty cycle or voltage value is the power value of the wireless power transmitting device. That is, the power of the wireless power transmission device can be represented by the voltage, duty setting and frequency applied to the inverter.

In the step of transmitting power by the wireless power transmitting apparatus, the set value (eg, voltage, duty frequency) is transmitted to the wireless power receiving apparatus using the FSK method.

At this time, the wireless power receiving device stops receiving the existing data signal (eg, ASK signal) and receives the FSK signal. As an example, the reception operation of the FSK signal includes a demodulation operation of the FSK signal.

The FSK signal may be transmitted at regular intervals. For example, the constant period may be a transmission period of a predetermined time (eg, 3 seconds, 5 seconds) or a predetermined number of data signals (eg, ASK signals).

The FSK signal may be transmitted simultaneously with wireless power. That is, S705 and S710 may be performed simultaneously.

Subsequently, the wireless power receiver detects a foreign object based on the transmission power measurement report (S715). For example, the FSK signal including the received power value measured by the wireless power receiver and the generated power measurement report is calculated, and if the difference value is greater than a predetermined reference value, it is determined as FOD. As another example, the wireless power receiving device determines that the FOD is the received power if the 'received power-transmission energy' is greater than or equal to a predetermined reference value.

For example, the measured received power value may be information indicating whether a difference between the power indicated by the transmission power measurement report and the requested power is greater than or equal to or less than a threshold. For example, if the difference between the power indicated by the transmission power measurement report and the required power is greater than the threshold, 'reception power measurement result = 1' is set, and the difference between the power indicated by the transmission power measurement report and the required power is the threshold value. If it is less than or equal to 'receive power measurement result = 0' can be set. Or, on the contrary, when the difference between the power indicated by the transmission power measurement report and the required power is greater than or equal to the threshold, 'reception power measurement result = 1' is set, and the difference between the power indicated by the transmission power measurement report and the required power is When the value is smaller than the threshold, 'reception power measurement result = 0' may be set. For example, suppose the threshold is 1W. In the situation where the power indicated by the transmission power measurement report is 12 W and the required power is 10 W as in the above example, the difference is 2 W, which is greater than the threshold of 1 W. In this case, the received power measurement result indicates 1. If the difference between the power indicated by the transmission power measurement report and the required power is greater than the threshold, this may mean that a foreign object has been detected. Therefore, the wireless power transmission device may recognize this as a foreign matter detection declaration.

The wireless power receiving device transmits an ASK signal including a foreign material detection result to the wireless power transmitting device (S720).

The ASK signal may include a power control signal, a FOD detection signal, an emergency signal, or a buffer signal.

Further, the ASK signal may include required power information of the wireless power receiving device. The required power information refers to information that the wireless power transmission device requests to generate wireless power based on a magnetic induction method, and the wireless power transmission device checks the required power information and transmits a control signal to induce the power indicated by the requested power information. It is the information to be generated. For example, when the requested power information indicates 10W, the wireless power transmission device generates a control signal to transmit 10W.

The ASK signal may be transmitted in the form of a control error packet, a rectified packet, or a charger state.

Subsequently, the wireless power transmission apparatus may transmit wireless power based on the received ASK signal (S725).

Since data signals (eg, ASK signals or FSK signals) cannot be transmitted and received at the same time, transmission or reception is sequentially performed. On the other hand, since the power is continuously generated through the induction frequency, it is possible to simultaneously transmit the power signal and the data signal. Accordingly, wireless power may be simultaneously or frequently transmitted regardless of when the ASK signal and the FSK signal are transmitted and received.

According to the above steps S720 and S725, the ASK signal and the wireless power may be transmitted and received multiple times.

When a certain period of time elapses with respect to step S710, the wireless power transmission device transmits a transmission power measurement report indicating the measured transmission power to the wireless power reception device (S730). For example, the wireless power transmission device transmits a transmission power measurement report to the wireless power reception device as an FSK signal. The constant period may be a transmission period of a predetermined time (eg, 3 seconds 5 seconds) or a predetermined number of data signals (eg, ASK signals).

Meanwhile, when it is determined that a foreign substance has been detected in the wireless power receiving apparatus, the wireless power transmission apparatus may perform a measure for detecting the foreign substance (not shown). For example, the wireless power transmission device may enter a blocking mode in which driving of the main coil is reduced or stopped. This prevents heat generation of parasitic loads and may limit or stop supply of inefficient induction power.

According to an embodiment of the present invention having the above-described configuration, the light irradiated through the light emitting unit propagates through the light guide unit, and the user can check the charging state through the light guide unit, so that the charging state in the wireless power transmission system is visible. It can be confirmed highly.

Moreover, by using the light guide portion to indicate the charging position, visibility to the charging position is increased. In addition, when such a wireless power transmission device is used in a flat-type furniture such as a table, the light guide portion is embedded in the flat panel of the furniture, thereby facilitating confirmation of a charging position and increasing visibility of a charging state.

The wireless power transmission device having improved visibility of the charging state described above and a furniture equipped with a wireless charging function equipped with the same are not limited to the configuration and method of the above-described embodiments, and the embodiments are various All or part of each of the embodiments may be selectively combined to constitute a modification.

100: wireless power transmission device
110: transport block
111: primary coil
113: object detection unit
115: converter
117: driving driver
120: light emitting unit
121: first light emitting module
122: second light emitting module
130: light guide unit (optical fiber)
131: branch
140: temperature sensor
150: transmission control unit
200: wireless power receiving device
210: secondary coil
220: rectifier
230: battery
240: receiving control
300: table
310: reputation (part)
311: coating layer

Claims (11)

In the wireless power transmission device is configured to be attached to the bottom surface of the flat portion of the furniture, the visibility of the charged state,
A transmission block including a primary coil for transmitting a wireless power signal;
A light emitting unit for displaying wireless charging or not;
A light guide unit for propagating light from the light emitting unit;
And a transmission control unit controlling the transmission block to transmit a wireless power signal to a wireless power receiving device, and controlling the light emitting unit based on charging state information from the wireless power receiving device,
The light guide portion is an optical fiber,
The light emitting unit includes a light emitting module and a cap,
The cap is configured to cover the light emitting module in order to block light emitted from the light emitting module and guide light emitted from the light emitting unit to the optical fiber, wherein the optical fiber is configured to control the charging state and charging position. In order to display, it is configured to extend from the light emitting portion located on the bottom surface of the flat plate portion to a top surface of the flat plate portion through a hole in the flat plate portion, and the wireless power transmission device having improved visibility of the charging state.
According to claim 1,
Further comprising a temperature sensor,
The transmission control unit,
When the temperature measured from the temperature sensor is equal to or greater than a reference value while simultaneously transmitting the wireless power signal, the wireless power transmission device having improved visibility of a charging state, which limits transmission of the wireless power signal.
According to claim 1,
The light emitting module,
A first light emitting module for indicating normal charging and
A wireless power transmission device comprising a second light emitting module for displaying charging incapacitance, with improved visibility in a charged state.
The method of claim 3,
The optical fiber,
The first light emitting module and the second light emitting module, the wireless power transmission device including a branch, which is connected to each other, to increase the visibility of the charging state.
The method of claim 3,
The optical fiber is a wireless power transmission device with improved visibility of the charging state, which is embedded so that light is irradiated from the surface of the flat-type furniture to the outside.
According to claim 1,
The transport block,
An object detector for transmitting a response signal generated according to the wireless power receiver from the primary coil to the transmission controller;
A converter connected to the primary coil; And
And a driving driver that transmits a driving signal to the converter when the wireless power receiving device is detected by the object detection unit under control of the transmission control unit.
Flat furniture; And
It includes a wireless power transmission device attached to the bottom surface of the flat portion of the flat-type furniture,
The wireless power transmission device,
A transmission block including a primary coil for transmitting a wireless power signal;
A light emitting unit for displaying wireless charging or not;
A light guide portion that propagates light from the light emitting portion and is embedded in a main surface of the flat plate portion so that the light can be irradiated to the outside; And
And a transmission control unit controlling the transmission block to transmit a wireless power signal to a wireless power receiving device, and controlling the light emitting unit based on charging state information from the wireless power receiving device,
The light guide portion is an optical fiber,
The light emitting unit includes a light emitting module and a cap,
The cap is configured to cover the light emitting module to block the light emitted from the light emitting module and to guide the light emitted from the light emitting unit to the optical fiber, wherein the optical fiber controls the charging state and charging position. In order to display, it is configured to extend from the light emitting portion located on the bottom surface of the flat plate portion to a top surface of the flat plate portion through a hole in the flat plate portion.
The method of claim 7,
The light guide portion is embedded in a position corresponding to the primary coil, so that the charging position can be displayed, wireless charging flat furniture.
The method of claim 7,
The light emitting module,
A first light emitting module for indicating normal charging and
A wireless chargeable flat panel furniture comprising a second light emitting module for indicating charging failure.
The method of claim 8,
The optical fiber,
The first light-emitting module and the second light-emitting module, each of which includes a branch portion, wirelessly chargeable flat furniture.
The method of claim 7,
Further comprising a transparent protective coating layer to coat the main surface of the flat portion, to protect the light guide portion, a wireless charging flat furniture.

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