KR20230156278A - Wireless power transmission device enhencing visibility of charging state, amd furniture having charging function by installing the same - Google Patents

Abstract

The present invention includes a transmission block including a primary coil for transmitting a wireless power signal; A light emitting unit for indicating wireless charging status; a light guide for propagating light from the light emitting unit; and a transmission control unit that controls the transmission block to transmit a wireless power signal to the wireless power reception device and controls the light emitting unit based on the charging state information from the wireless power reception device, providing visibility of the charging state. This relates to an enhanced wireless power transmission device and furniture equipped with the same and equipped with a wireless charging function.

Description

Wireless power transmission device that increases visibility of charging status and furniture equipped with wireless charging function {WIRELESS POWER TRANSMISSION DEVICE ENHENCING VISIBILITY OF CHARGING STATE, AMD FURNITURE HAVING CHARGING FUNCTION BY INSTALLING THE SAME}

The present invention relates to a wireless power transmission device with increased visibility of the charging state and furniture equipped with the same and equipped with a wireless charging function.

In general, a battery pack is used to supply power for the operation of portable terminals (cell phones, PDAs, etc.) while receiving power (electrical energy) from an external charger and charging it. It is a battery that charges electrical energy. It consists of a cell and a circuit for charging and discharging the battery cell (supplying electrical energy to a portable terminal).

The electrical connection method between the charger and the battery pack for charging electric energy to the battery pack used in these portable terminals is as follows. There is a terminal supply method that receives commercial power, converts it into voltage and current corresponding to the battery pack, and supplies electric energy to the battery pack through the terminals of the battery pack.

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

In particular, there was a risk of fire, etc., occurring if foreign substances accumulated on both terminals due to this instantaneous discharge phenomenon.

In addition, there is a problem that the electric energy charged in the battery pack is naturally discharged to the outside through the terminal of the battery pack due to moisture, etc., and this has the disadvantage of reducing the lifespan and performance of the battery pack.

Recently, in order to solve the above problems, non-contact charging systems and control methods using a wireless power transmission method have been proposed.

There have been attempts to apply this non-contact charging system to smartphones and tablet PCs that require frequent charging, especially because there is no need for users to combine genders for charging. Recently, in the case of smartphones equipped with various apps, users have had the inconvenience of carrying a separate rechargeable battery (external battery) due to the need for frequent battery charging.

Accordingly, when the user does not use the smartphone even for a moment, it has become necessary to prevent the smartphone from being discharged by briefly charging it.

Accordingly, a wireless power transmission device (wireless charger) is attached to a flat piece of furniture such as a table, and when the user sits in front of the table to work or eat, his or her smart phone (wireless power reception device) is placed at the charging location on the table. You can start charging by placing it on the

Likewise, when installing a wireless power transmission device in furniture, the wireless power charging device must be placed on the bottom to protect the exterior of the furniture. In this case, it was difficult to mark the charging location or charging status on the table.

The present invention was conceived to solve the above-described problems, and includes a wireless power transmission device that not only clearly displays the charging location but also visually confirms whether charging is progressing, increasing the visibility of the charging state, and a device equipped with the same. The goal is to provide furniture with wireless charging capabilities.

A wireless power transmission device with increased visibility of the charging state, which is an embodiment of the present invention devised to solve the above-mentioned problems, includes a transmission block including a primary coil for transmitting a wireless power signal; A light emitting unit for indicating wireless charging status; a light guide for propagating light from the light emitting unit; and a transmission control unit that controls the transmission block to transmit a wireless power signal to the wireless power reception device, and controls the light emitting unit based on charging state information from the wireless power reception device.

Here, the wireless power transmission device with increased visibility of the charging state further includes a temperature sensor, and the transmission control unit, if the temperature measured from the temperature sensor is greater than a reference value while the wireless power signal is simultaneously transmitted, the wireless power transmission device All transmission of power signals can be restricted.

Here, the light guide part 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 portion connecting the first light emitting module and the second light emitting module, respectively.

Here, the optical fiber may be buried so that light is emitted from the surface of the flat furniture to the outside.

Here, the transmission block includes: an object detection unit that transmits a response signal generated according to the wireless power reception device from the primary coil to the transmission control unit; A converter connected to the primary coil; and a driving driver that sends a driving signal to the converter when the wireless power receiving device is detected by the object detection unit under the control of the transmission control unit.

In another embodiment of the present invention, flat-type furniture capable of wireless charging includes a wireless power transmission device attached to the bottom of the flat portion of the flat-type furniture, wherein the wireless power transmission device is a primary device for transmitting a wireless power signal. a transmission block containing a coil; A light emitting unit for indicating wireless charging status; a light guide part embedded in the main surface of the flat part to propagate light from the light emitting part and allow the light to be irradiated to the outside; and a transmission control unit that controls the transmission block to transmit a wireless power signal to the wireless power reception device, and controls the light emitting unit based on charging state information from the wireless power reception device.

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

Here, the light guide part may be buried in a position corresponding to the primary coil to indicate the charging position.

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 portion connecting the first light emitting module and the second light emitting module, respectively.

Here, the wireless charging-capable furniture may further include a transparent protective coating layer that protects the light guide portion by coating the main surface of the flat portion.

According to an embodiment of the present invention having the above-described configuration, the light irradiated through the light emitting part is propagated through the light guide, and the user can check the charging state through the light guiding part, thereby improving the visibility of the charging state in the wireless power transmission system. You can check it at a high level.

Moreover, by using the light guide to indicate the charging position, visibility of the charging position is increased. In addition, when such a wireless power transmission device is used in flat furniture such as a table, the light guide is embedded in the flat part of the furniture so that the charging position can be easily confirmed and visibility of the charging state is increased.

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

The suffixes “module” and “part” for components used in the following description are given or used interchangeably only for the ease of preparing the specification, and do not have distinct meanings or roles in themselves.

Below, a dining table is shown 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 with a flat surface on which to place multiple smartphones, such as office tables, dressers, end tables, and shelves.

FIG. 1 is a perspective view for explaining the appearance of a wireless power transmission device with improved visibility of a charging state, which is an embodiment of the present invention, and FIG. 1B is a diagram for explaining the light emitting unit and the light guide unit in FIG. 1A. As shown in FIG. 1A, when the wireless power transmission device 100, which is an embodiment of the present invention, is installed on the bottom of the table 300, the wireless power reception device 200 is installed at 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 a 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 status, a light emitting unit 120 may be installed on one end of the main surface of the wireless power transmission device 100.

A light guide part 130 is connected to this light emitting part, and the light guide part 130 made of an optical fiber is pulled out to the upper surface of the table 300 through a fine through hole previously installed in the table. Accordingly, the light guide part 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 part 130.

A specific detailed drawing of the light emitting unit is Figure 1B. As shown in FIG. 1B, the light emitting unit 120 includes a first light emitting module 121 (e.g., a module emitting green light) for displaying a normal state, and a second light emitting module (e.g., a module emitting green light) for displaying an inability to charge. 122) (for example, a module emitting red light), and a cap 123 that covers and protects the first light emitting module 121 and the second light emitting module 122. The cap 123 not only protects the first light emitting module 121 and the second light emitting module 122, but also guides all of the light emitted from the light emitting modules to the light guide 130 without being exposed to the outside. It functions to do so.

An example in which each light emitting module 121 and 122 emits light of different colors has been described, but the present invention is not limited to this, and a single light emitting module may display the charging state through various colors.

Meanwhile, the optical fiber 130, which is a light guiding part, may be connected to the light emitting part 120 and extended. That is, the optical fiber 130 has a branch part 131, and the branch part 131 is attached to the first light emitting module 121 and the second light emitting module 122, respectively. The branch portion 131 is located inside the cap 123. The light guide part 130 functions to propagate the light emitted from the light emitting part 120. In the present invention, the light guide part 130 is embedded on the table so that the user places his/her smartphone 200 on the table. When charging by placing it in the charging position, the charging state of one's smartphone 200 can be confirmed through the light emitted from the light guide unit 130. This will be explained in more detail in FIGS. 3 and 4.

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

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

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

The wireless power transmission device 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 have been described in FIG. 1, their description will be omitted.

As shown in FIG. 2, the transmission block includes a primary coil 111, a converter 115 connected to the primary coil 111, a driving driver 117 connected to the converter 115, and a primary coil 111. It may include an object detection unit 113 that is connected to the coil 111 and detects whether the wireless power reception device 200 is in a charging position.

The primary coil 111 is a component that oscillates a wireless power signal, and oscillates a wireless power signal to the wireless power receiving device 200 using electromagnetic induction. The primary coil 111 may be circular, oval, track-shaped, square, or polygonal in shape.

In the present invention, the case where the transmission block 110 has one primary coil 111 is described, but the present invention is not limited to this, and the primary coils 111 may be installed in pairs.

The converter 115 generates transmission power for generating a power signal to be transmitted under 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 in the charging position, the transmission control unit 150 sends a power control signal to the driving driver 117 to cause the converter 115 to transmit a power signal having the required power value. is transmitted, and accordingly, the driving driver 117 controls the operation of the converter 115 by the transmitted power control signal. Accordingly, the converter 115 applies the transmission 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 intensity is transmitted to the charging position. It is to be transmitted to the wireless power receiving device 200 in .

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

The object detection unit 113 detects a change in the load of the primary coil 111 and detects whether there is an object at the charging location. Accordingly, the transmission control unit 150 sends a digital ping signal to the driving driver 117. ) is controlled to oscillate through the transmission coil, and as a response signal, a signal strength packet signal is received from the wireless power receiving device 200 to determine whether the object is caused by the wireless power receiving device 200. (That is, it functions as an ID confirmation unit) and performs a function of filtering and processing charging state information transmitted from the wireless power receiving device 200. That is, when a signal including an object response signal and charging state information, which is a signal strength packet signal for the digital ping of the object detection signal transmitted through the primary coil 111, is received, it filters and processes the signal.

The transmission control unit 150 receives and confirms the decision result of the object detection unit 113, analyzes the object response signal received from the primary coil 111, and transmits wireless power through the primary coil 111. It serves to transmit a power signal for transmitting a 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 reception 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 emit green light, so that the green light propagates to the light guide unit 130. If it is determined that the wireless power receiving device 200 is not being charged normally, the second light emitting module 122 is controlled to emit red light so that the red light propagates to the light guide unit 130.

By operating in this way, the state of charge can be known through the light emission color of the optical fiber 130. In this way, the light guide part 130 may be made of an optical fiber, and the optical fiber may be buried so that light is emitted from the surface of the flat furniture to the outside. This will be explained in more detail in FIGS. 3 and 4.

Meanwhile, the temperature sensor 140 functions to detect that the wireless power transmission device 100 is overheated due to foreign substances. If a metallic foreign object, such as a coin, is placed at the charging position of the wireless power transmission device 100 during or at the beginning of wireless charging, wireless power transmission will not be performed normally, and accordingly, power waste will occur, thereby causing wireless power transmission. The transmission device 100 becomes overheated.

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

Meanwhile, although not shown in the drawing, an audio output module may be further included. Accordingly, the transmission control unit 150 can control the state of normal charging and abnormal charging to be output through the audio output module. That is, in the case of normal charging, the beep sound indicating the normal charging state is output for a certain period of time (e.g. 3 seconds), and then the beep sound is no longer output. However, if the charging is abnormal, the beep sound indicating the abnormal state is continuously output. The audio output module can be controlled as much as possible.

Meanwhile, the wireless power receiving device 200, which receives power by receiving a power signal, includes a secondary coil 210 that generates induced power by the transmitted power signal, and a rectifier 220 that rectifies the induced power. and a battery 230 and a reception control unit 240 that are charged with rectified power.

Here, the battery cell module 230 includes protection circuits such as overvoltage and overcurrent prevention circuits and temperature detection circuits, and also includes a charging management module that collects and processes information such as the charging state of the battery cell. .

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

Figure 3 is a diagram for explaining the appearance of furniture equipped with a wireless charging function and equipped with a wireless power transmission device that improves visibility of the charging state, which is an embodiment of the present invention. As shown, the wireless power transmission device 100 with increased visibility of the charging state described in FIGS. 1 and 2 may be attached to the bottom of the flat portion 310 of a flat furniture such as the table 300. Additionally, the optical fiber 130 extending from one end of the wireless power transmission device 100 is exposed upward through a hole in the flat plate portion 310, and may be located in a buried groove formed at the top. This buried groove may be formed at a position corresponding to the position of the primary coil 111. Accordingly, when external power is supplied to the wireless power transmission device 100, the light emitting part 120 emits light, and the optical fiber 130 partially exposed at the upper part of the flat part 310 emits light, and accordingly. , users can check the charging location.

Then, when the user places his/her smartphone (200: wireless power receiving device) at the charging location, charging begins. When charging is normal, the transmission control unit 150 controls the light emitting unit 120 to emit green light, so that the user can see that the optical fiber 130 glows green to know that it is normally charged. Conversely, if charging is not performed normally, the transmission control unit 150 controls the light emitting unit 120 to emit red light, so that the user can confirm that the optical fiber 130 glows red. Accordingly, the user can see that charging is not currently taking place.

In Figure 4, the installation state of the wireless power transmission device and optical fiber is explained through a cross-sectional view of the table.

Figure 4 is a cross-sectional view illustrating a state in which a wireless power transmission device with increased visibility of the charging 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 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. Meanwhile, the optical fiber 130 extending from the wireless power transmission device 100 may be drawn out through a micro-through hole formed perpendicular to the flat plate and installed so as to be partially exposed to the upper surface of the flat plate. That is, a fine through hole is formed at a position corresponding to the light emitting unit 120 of the flat plate 310, and the optical fiber 130 is drawn out to the upper surface of the flat plate 310 through the fine through hole, and then charged. In order to indicate the position, the optical fiber 130 is disposed to be exposed 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 can be protected by this transparent coating layer 311.

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

Figure 5 is a flowchart showing a method of detecting foreign matter 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 matter detection operation is performed before initial charging (S200). As an example, the foreign matter detection operation before initial charging is shown in FIG. 6.

If a foreign substance is detected before initial charging (S205), a power limiting operation corresponding to the detection of the foreign substance is performed (S225).

If no foreign matter is detected before initial charging (S205), when charging begins, a foreign matter detection operation is performed during charging (S210).

As an example, foreign substances can be detected by performing one-way communication during charging. As an example, the foreign matter detection operation using one-way communication during charging is shown in FIG. 9.

As another example, foreign substances can be detected by performing two-way communication during charging. As an example, the foreign matter detection operation using two-way communication during charging is shown in Figure 10.

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

If a foreign object is detected during charging (S215), a power limiting operation in response to the foreign object detection is performed as in step S225.

If no foreign matter is detected during charging (S215), if a problem occurs in power transmission due to fine undetected foreign matter, the power is limited based on the temperature sensor 130 (or thermistor) to protect power transmission (e.g., Turn off the power) (S220). The temperature sensor may be attached to a receiving device or may be attached to a transmitting device.

Alternatively, even after the power limiting operation in response to foreign matter detection is performed in step S225, if a problem occurs in power transmission due to a fine undetected foreign matter, the power is limited based on the temperature sensor (or thermistor) to protect power transmission.

Figure 6 is a flowchart showing a method of detecting foreign matter in a wireless power transmission system including a wireless power transmission device with increased visibility of the charging state according to another embodiment of the present invention.

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

If a foreign substance is detected before initial charging (S305), a power limiting operation corresponding to the detection of the foreign substance is performed (S315).

If foreign substances are not detected before initial charging (S305), if there is a problem with power transmission due to fine undetected foreign substances, the power is limited based on the temperature sensor (or thermistor) to protect power transmission (e.g., power Hang up)(S310). The temperature sensor may be attached to a receiving device or may be attached to a transmitting device.

Alternatively, even after the power limiting operation in response to foreign matter detection is performed in step S315, if a problem occurs in power transmission due to a fine foreign matter that has not been detected, the power is limited based on a temperature sensor (or thermistor) to protect power transmission.

FIG. 7 is a flowchart showing a method of detecting foreign matter in a wireless power transmission system including a wireless power transmission device with increased visibility of the charging state according to another embodiment of the present invention.

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

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

If no foreign matter is detected during charging (S405), if there is a problem with power transmission due to fine foreign matter that has not been detected, the power is limited based on the temperature sensor (or thermistor) to protect power transmission (e.g., cut off power) )(S410). The temperature sensor may be attached to a receiving device or may be attached to a transmitting device.

Alternatively, even after the power limiting operation in response to foreign matter detection is performed in step S415, if a problem occurs in power transmission due to a fine foreign matter that has not been detected, the power is limited based on a temperature sensor (or thermistor) to protect power transmission.

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

One. Foreign matter detection operation before initial charging

FIG. 8 is a flowchart illustrating a method of detecting foreign matter in a wireless power transmission system including a wireless power transmission device with increased visibility of the charging state according to an embodiment of the present invention. This 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, and at this time, the wireless power transmission device transmits a power signal at the operating point to the wireless power reception device (S500).

When receiving a power signal of the ping phase, the wireless power receiving device generates a signal strength packet indicating the received strength of the power signal and transmits it to the wireless power transmitting device (S505). Then, the wireless power receiving device generates an identification packet indicating a unique ID of the wireless power receiving device and configuration information of the wireless power receiving device, and transmits the identification packet and configuration information to the wireless power transmitting device (S510).

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

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

If it is charging in step S530, the wireless power receiving device compares the received power to the required power, generates a power control packet based on the result, and transmits it to the wireless power transmitting device (S535). If it is not charging in step S535, the wireless power receiving device determines whether the initial voltage V _i is in a hold state (S540). If the steady-state value of the initial voltage V _i is within the reference voltage range (for example, 7.0V to 10.5V), the initial setup of the wireless power receiving device is completed. As a result, the initial voltage _Vi is in a hold state, and the wireless power receiving device can enter the foreign matter detection phase.

If V _i is not in the 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 matter detection phase. Here, the wireless power reception device generates a foreign matter status packet and transmits it to the wireless power transmission device (S545).

The foreign matter status packet according to the present invention includes a preamble, header, message, and checksum. The preamble can consist of a minimum of 11 bits and a maximum of 25 bits, and the value of all bits can be set to 0. The preamble is used by the wireless power transmission device to accurately detect the start bit of the header of the foreign object status packet and synchronize with the incoming data.

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

The wireless power transmission device determines whether the received packet is a foreign object packet based on the value of the header or message of the received packet. And if it is determined that the foreign matter status packet has been received, the wireless power transmission device 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 device.

2. Foreign object detection during charging

2-1. Foreign matter detection using one-way communication during charging

Figure 9 is an operation flowchart of a wireless power transmission system including a wireless power transmission device with increased visibility of the charging state according to another embodiment of the present invention. This corresponds to step S210 of FIG. 2 or step S400 of FIG. 4.

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

If the detected object is a wireless power receiver, the wireless power transmitter enters the charging mode and transmits wireless power to the wireless power receiver (S605). In charging mode, the wireless power transmission device applies 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 obtains a current measurement value from the current flowing in the primary coil (S610). The current measured by the wireless power transmission device may be alternating current. The current measurement value may be converted to a DC value suitable for recognition by a control unit in the wireless power transmission device. 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 suitable for interpretation by the control unit, 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 device performs foreign matter detection using any one or a combination of two or more of the following parameters, such as reference current I _ref , reference range (I _low ~ I _high ), reference AC signal, and foreign matter detection time t (S615 ). And parameters such as reference current I _ref , reference range (I _low to I _high ), reference AC signal, and foreign matter detection time t may be pre-stored in the wireless power transmission device as initial setting values. If a foreign substance is not detected, the wireless power transmission device continuously transmits power to the wireless power reception device (S620). Then, the wireless power transmission device obtains the current measurement value of the primary coil again at a time point t predetermined by the system or standard (S610), and can attempt to detect foreign substances based on this (S615).

On the other hand, when a foreign substance is detected, the wireless power transmission device blocks the wireless power being transmitted to the wireless power reception device (S625).

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

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

For example, performing two-way communication means that when power is transmitted from a transmitting device to a receiving device, the receiving device informs the transmitting device of the received power value, and if the power loss is greater than a predetermined standard value, it is determined to be FOD. It says what to do. For example, performing two-way communication means that if 7 to 10W of power is transmitted from the transmitting device to the receiving device and the receiving device receives 5W of power, the received power value '5W' is notified to the transmitting device, and the power loss is 2W. Since it is greater than the predetermined standard value of 1W, it is judged as FOD. Through this, FOD can be detected in the power transmission stage.

To describe the two-way communication 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 a charging standby state until the wireless power reception device is searched.

If the detected object is a wireless power receiver, the wireless power transmitter enters charging mode and transmits wireless power to the wireless power receiver (S705). In charging mode, the wireless power transmission device applies 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). As an example, the wireless power transmission device transmits a transmission power measurement report as an FSK signal to the wireless power reception device. 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 the transmission time of the FSK signal. The constant period may be a section in which a certain number of data signals are transmitted (eg, the ASK signal is constant).

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

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

As an example, the wireless power transmission device may measure the power generated in the main coil according to the AC current signal, construct a transmission power measurement report indicating the measured generated power, and transmit it to the wireless power reception device. In this way, control information may be transmitted through a path from the wireless power transmission device to the wireless power reception device (for example, control information may be transmitted as an FSK signal), or through a path from the wireless power reception device to the wireless power transmission device. Two-way communication in which control information is transmitted is possible.

The wireless power transmission device performs PWM using an inverter and generates a frequency allowed for the required power (or required power) of the wireless power reception 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 expressed as the voltage applied to the inverter, duty setting, and frequency.

In the step of transmitting power, the wireless power transmitter transmits a 'transmission power value' of a set value (eg, voltage, duty frequency) to the wireless power receiver 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, a reception operation of an 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 and 5 seconds) or a predetermined number of data signals (eg, ASK signal).

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

Next, the wireless power receiving device detects foreign matter based on the transmission power measurement report (S715). For example, the FSK signal including the received power value measured by the wireless power receiving device and the generated power measurement report is calculated, and if the difference value is greater than a predetermined reference value, it is determined to be FOD. As another example, the wireless power receiving device determines it to be FOD if 'received power-transmitted power' is greater than a predetermined reference value.

For example, the measured received power value may be information indicating whether the difference between the power indicated by the transmitted power measurement report and the required power is greater than, 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, 'received power measurement result = 1' is set, and the difference between the power indicated by the transmission power measurement report and the required power is set to the threshold. If it is less than or equal to, it can be set to 'received power measurement result = 0'. Or, conversely, 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, 'received power measurement result = 1' is set, and the difference between the power indicated by the transmission power measurement report and the required power is set. When it is less than the threshold, it may be set to 'received power measurement result = 0'. For example, let's say the threshold is 1W. As in the example above, in a situation where the power indicated by the transmission power measurement report is 12W and the required power is 10W, the difference is 2W, which is greater than the threshold of 1W. 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 substance has been detected. Therefore, the wireless power transmission device can recognize this as a foreign substance detection declaration.

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

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

Additionally, the ASK signal may include required power information of the wireless power reception device. Required power information refers to information that requires a wireless power transmission device to generate wireless power based on magnetic induction. The wireless power transmitter checks the required power information and sends a control signal to induce the power indicated by the required power information. This is information that causes it to occur. For example, when the required 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, rectified packet, or charger state.

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

Since it is impossible to simultaneously transmit and receive a data signal (eg, ASK signal or FSK signal), transmission or reception is performed sequentially. On the other hand, because power continues to be generated through the induced frequency, it is possible for the power signal and data signal to be transmitted simultaneously. Therefore, wireless power can be transmitted simultaneously or at any time, regardless of when the ASK signal and the FSK signal are transmitted and received.

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

When a certain period has elapsed in 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). As an example, the wireless power transmission device transmits a transmission power measurement report as an FSK signal to the wireless power reception device. The constant period may be a transmission period of a predetermined time (eg, 3 seconds and 5 seconds) or a predetermined number of data signals (eg, ASK signal).

Meanwhile, if it is determined that a foreign substance has been detected in the wireless power reception device, the wireless power transmission device may take action to detect the foreign substance (not shown). For example, the wireless power transmission device may enter a blocking mode in which operation of the main coil is reduced or stopped. This prevents the parasitic load from generating heat, and the supply of inefficient induced power can be limited or stopped.

According to an embodiment of the present invention having the above-described configuration, the light irradiated through the light emitting part is propagated through the light guide, and the user can check the charging state through the light guiding part, thereby improving the visibility of the charging state in the wireless power transmission system. You can check it at a high level.

Moreover, by using the light guide to indicate the charging position, visibility of the charging position is increased. In addition, when such a wireless power transmission device is used in flat furniture such as a table, the light guide is embedded in the flat part of the furniture so that the charging position can be easily confirmed and visibility of the charging state is increased.

The wireless power transmission device with increased visibility of the charging state described above and 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 embodiment may be selectively combined so that modifications can be made.

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

Claims (1)

In the wireless power transmission device with increased visibility of the charging state, which is configured to be attached to the bottom of the flat portion of furniture,
A transmission block including a primary coil for transmitting a wireless power signal;
A light emitting unit for indicating wireless charging status;
a light guide for propagating light from the light emitting unit;
A transmission control unit that controls the transmission block to transmit a wireless power signal to a wireless power reception device and controls the light emitting unit based on charging state information from the wireless power reception device,
The light guide 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 light emitted from the light emitting module and guide the light emitted from the light emitting unit to the optical fiber, and the optical fiber determines the charging state and charging position. In order to display, it is configured to extend from the light emitting portion located on the bottom of the flat portion to the upper surface of the flat portion through a hole in the flat portion,
The light emitting module is,
a first light emitting module for indicating normal charging by emitting light of a first color; and
a second light-emitting module for indicating charging failure by emitting light of a second color, wherein the first color is different from the second color, and light emitted from the first light-emitting module and the second light-emitting module The cap covers the first light-emitting module and the second light-emitting module so that they are not exposed to the outside of the cap.

Images