CN117458727A

CN117458727A - Protective housing and wireless charging system

Info

Publication number: CN117458727A
Application number: CN202311485726.4A
Authority: CN
Inventors: 武渊
Original assignee: Honor Device Co Ltd
Current assignee: Honor Device Co Ltd
Priority date: 2023-11-08
Filing date: 2023-11-08
Publication date: 2024-01-26

Abstract

The application relates to the technical field of wireless charging, and discloses a protective shell and a wireless charging system, wherein the protective shell is used for being sleeved on first electronic equipment, the first electronic equipment comprises a first coil, and the protective shell comprises a second coil; when the protective shell is sleeved on the first electronic equipment, the second coil can receive wireless power supply of a third coil in the second electronic equipment and can wirelessly charge the first coil. The wireless coil in the protective housing can receive the electric energy from wireless charging equipment to can charge to the receiving coil in electronic equipment, so that electronic equipment can indirectly receive wireless charging from wireless charging equipment, thereby promoting charging efficiency.

Description

Protective housing and wireless charging system

Technical Field

The application relates to the technical field of wireless charging, in particular to a protective housing and a wireless charging system.

Background

With the widespread use of portable electronic devices such as mobile phones and tablet computers, more and more electronic devices use wireless charging devices to charge them. The wireless charging equipment is internally provided with a wireless charging transmitting coil, and the electronic equipment is internally provided with a wireless charging receiving coil. When the wireless charging is performed, the electronic equipment is close to the wireless charging equipment, and the transmitting coil in the wireless charging equipment can charge the receiving coil in the electronic equipment.

At present, in order to enable electronic equipment to have better anti-falling and anti-collision performances, a user often sets a protective shell on a shell of the electronic equipment. When electronic equipment carries out wireless charging under the state of cover establishes the protective housing, because the protective housing is located between transmitting coil and the receiving coil generally, therefore the protective housing has increased the distance between transmitting coil and the receiving coil, can lead to wireless charging equipment to electronic equipment's wireless charging efficiency reduction, can not realize wireless charging even.

Disclosure of Invention

Some embodiments of the present application provide a protective case and a wireless charging system, and the present application is described in terms of the following aspects, which may be referred to with reference to each other.

In a first aspect, the present application provides a protective case for being sleeved on a first electronic device, the first electronic device including a first coil, the protective case including a second coil; when the protective shell is sleeved on the first electronic equipment, the second coil can receive wireless power supply of a third coil in the second electronic equipment and can wirelessly charge the first coil.

According to the embodiment of the application, after receiving the electric energy from the wireless charging device, the wireless coil in the protective shell charges the receiving coil in the electronic device, so that the electronic device indirectly receives the wireless charging from the wireless charging device. That is, in the process that the wireless charging device carries out wireless charging to the electronic device, the wireless coil in the protective housing can play a role in relay of energy transmission, so that the charging efficiency that the wireless charging device carries out wireless charging to the electronic device is improved.

In some embodiments, when the protective case is sleeved on the first electronic device, the second coil has a first distance from the first coil, and the second coil can have a second distance from the third coil, so that the third coil can wirelessly charge the first coil through the second coil; when the protective shell is not sleeved on the first electronic equipment, the first coil can have a third distance from the third coil, so that the third coil can charge the first coil wirelessly; wherein the third distance is greater than the first distance and greater than the second distance.

According to the embodiment of the application, the charging efficiency of the transmitting coil for wirelessly charging the receiving coil through the relay coil is further improved, so that the wireless charging efficiency of the wireless charging equipment to the electronic equipment is improved.

In some embodiments, when the protective case is not sleeved on the first electronic device, the third coil can wirelessly charge the first coil with the first efficiency; when the protective shell is sleeved on the first electronic device, the third coil can wirelessly charge the first coil through the second coil with second efficiency; wherein the second efficiency is higher than the first efficiency.

In some embodiments, the protective housing includes a capacitor, the capacitor and the second coil together forming an oscillating circuit capable of generating an oscillating current in the second coil; the capacitor has a preset capacitance value, and the capacitance value enables the second efficiency to be higher than the first efficiency.

According to the embodiment of the application, by setting the capacitance value of the capacitor, when the wireless charging is performed, the charging efficiency eta 2 of the receiving coil through the relay coil for indirectly charging the receiving coil is higher than the charging efficiency of the transmitting coil for directly charging the receiving coil.

In some embodiments, the capacitor is a capacitance-tunable capacitor.

According to the embodiment of the application, the charging efficiency can be improved when the wireless charging equipment carries out wireless charging on the electronic equipment sleeved with the protective shell.

In some embodiments, the protective housing includes a circuit board disposed therein, the circuit board including a plurality of layers of metal coils disposed in a stacked arrangement, the plurality of layers of metal coils being electrically connected to one another to form the second coil.

According to embodiments of the present application, a double-sided arrangement of metal coils is utilized to enable the relay coil to be used to receive power from the transmit coil and to be used to charge the receive coil.

In some embodiments, the circuit board further includes an insulating layer disposed between adjacent two layers of metal coils.

In some embodiments, a via is provided in the insulating layer, and a conductor is provided in the via to connect adjacent two layers of metal coils.

In some embodiments, the surface of the circuit board is provided with a first bonding pad and a second bonding pad, the circuit board comprises a first lead and a second lead, one end of the second coil is electrically connected with the first bonding pad through the first lead, and the other end of the second coil is electrically connected with the second bonding pad through the second lead; the protective case includes a capacitor, the capacitor and the second coil together forming an oscillating circuit capable of generating an oscillating current in the second coil, and positive and negative electrodes of the capacitor are soldered to the first and second pads, respectively.

According to the embodiment of the application, the whole thickness of the capacitor and the relay coil in the X-axis direction is reduced, so that the relay coil and the capacitor are light and thin when arranged in the protective shell.

In some embodiments, the capacitor is disposed in a wall of the protective case.

In a second aspect, the present application provides a wireless charging system, where the wireless charging system includes a first electronic device and a protective case provided by any embodiment of the first aspect of the present application, where the protective case is configured to be sleeved on the first electronic device, and the first electronic device includes a first coil; when the protective shell is sleeved on the first electronic equipment, the second coil can receive wireless power supply of a third coil in the second electronic equipment, and the first coil can be charged wirelessly. The advantages achieved by the second aspect may refer to the advantages of the protective case provided by any embodiment of the first aspect, and will not be described herein.

In a third aspect, the present application further provides a wireless charging system, where the wireless charging system includes a first electronic device, a second electronic device, and a protective case provided in any embodiment of the first aspect of the present application, the first electronic device includes a first coil, and the second electronic device includes a third coil: when the protection shell is sleeved on the first electronic equipment, the second coil can receive wireless power supply of the third coil and can wirelessly charge the first coil. The advantages achieved by the third aspect may refer to the advantages of the protective case provided by any embodiment of the first aspect, and are not described herein.

In some embodiments, when the protective case is sleeved on the first electronic device, the first coil, the second coil and the third coil can be sequentially arranged along the first direction, the distance between the center of the first coil and the center of the third coil in the second direction is 3 mm-5 mm, and the second direction is perpendicular to the first direction.

Drawings

Fig. 1A is a schematic cross-sectional structure diagram of a wireless charging device charging an electronic device in a wireless charging system according to an embodiment of the present application, where an X-axis direction is a matching direction of the wireless charging device and the electronic device when the wireless charging device charges the electronic device;

Fig. 1B is a schematic circuit diagram of a wireless charging device for wirelessly charging an electronic device in a wireless charging system according to an embodiment of the present application;

fig. 1C is an equivalent circuit diagram of a wireless charging device for wirelessly charging an electronic device in a wireless charging system provided in an embodiment of the present application;

fig. 2A is a schematic cross-sectional structure diagram of a wireless charging device provided in some embodiments for wirelessly charging an electronic device sleeved with a protective case, where an X-axis direction is a matching direction of the wireless charging device when the wireless charging device charges the electronic device sleeved with the protective case;

FIG. 2B is a schematic circuit diagram of a wireless charging device provided in some embodiments for wirelessly charging an electronic device having a protective case sleeved thereon;

fig. 3 is a schematic cross-sectional structure diagram of a wireless charging device for wirelessly charging an electronic device when a protective shell is sleeved on the electronic device, where an X-axis direction is a matching direction of the wireless charging device when the wireless charging device charges the electronic device sleeved with the protective shell;

fig. 4 is a schematic diagram of a relay circuit in a protective case according to an embodiment of the present disclosure;

fig. 5 is a circuit diagram of coupling a transmitting coil of a transmitting circuit, a relay coil of a relay circuit, and a receiving coil of a receiving circuit according to an embodiment of the present application;

Fig. 6 is a graph showing a change in charging efficiency of the relay circuit capacitor provided in the protective case according to the embodiment of the present application;

fig. 7A is a top view of a protective case provided in an embodiment of the present application;

fig. 7B is a cross-sectional view of the protective case provided in the embodiment of the present application, where the X-axis direction is the thickness direction of the protective case, and is also the mating direction of the wireless charging device when charging the electronic device sleeved with the protective case;

fig. 7C is a schematic structural diagram of a relay coil in a protective case according to an embodiment of the present disclosure;

FIG. 7D is a cross-sectional view of M-M in FIG. 7C, wherein the X-axis direction is the thickness direction of the protective shell;

fig. 8 is a schematic cross-sectional structure of a transmitting coil in a wireless charging system according to an embodiment of the present application, where an X-axis direction is a matching direction of a wireless charging device when charging an electronic device sleeved with a protective case;

fig. 9A is a top view of a receiving coil and a relay coil according to an embodiment of the present application in the X-axis direction;

fig. 9B is a top view of the receiving coil, the relay coil, and the transmitting coil provided in the embodiment of the present application in the X-axis direction;

fig. 9C is a top view of another receiving coil, relay coil, and transmitting coil according to an embodiment of the present application.

Detailed Description

Specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

For ease of understanding, some terms that may be relevant to embodiments of the present application are first described.

(1) And a TX end. Also known as a wireless charging transmitter, is a device capable of transmitting electrical energy to a receiver by radio waves. The TX end converts electrical energy into radio waves and transmits the radio waves, usually based on electromagnetic induction and resonance techniques. By way of example, a wireless charging transmitter may include a power supply input port, a transmit coil, and a capacitor in series with one another. The power supply input port can be connected with an external power supply so that the external power supply supplies power to the wireless charging transmitter. When an external power source supplies power to the wireless charging transmitter, an oscillating current can be generated in the transmitting coil, thereby generating an oscillating magnetic field in space.

(2) And an RX end. Also called a wireless charging receiver, is a device capable of receiving radio waves emitted from a TX terminal and converting the radio waves into electric energy. The RX side typically receives power from the TX side based on electromagnetic induction and resonance techniques. Illustratively, the wireless charging receiver may include a battery, a receiving coil, and a capacitor in series with one another. When the receiving coil is positioned in the oscillating magnetic field generated by the transmitting coil, the oscillating current can be generated under the action of electromagnetic induction, so that the receiving coil can receive the electric energy from the TX end. The receiving coil, upon receiving power from the TX end, can store the power in a battery connected thereto.

(3) And (3) coupling. During wireless charging, the transmitting coil in the TX end may generate an oscillating current, thereby generating an oscillating magnetic field in space. When the receiving coil in the RX end is in the oscillating magnetic field, the receiving coil can generate oscillating current under the action of the oscillating magnetic field. Thus, energy at the TX end can be transferred into the RX end through an energy interaction between the transmit coil and the receive coil, which is referred to as "coupling" between the transmit coil and the receive coil. That is, by coupling between the transmit coil and the receive coil, the transfer of energy between different devices may be achieved.

As described above, when an electronic device (also referred to as a "charged device" or "RX terminal" as a first electronic device) is sleeved with a protective case, a wireless charging device (also referred to as a "TX terminal" as a second electronic device) is used to wirelessly charge the electronic device, there is a problem that charging efficiency is lowered and even charging is impossible.

The specific forms of the electronic device and the wireless charging device are not limited in the application. For example, the electronic device may be any device capable of receiving wireless charging, such as a tablet computer, a camera, a vehicle-mounted device, a wearable device, augmented reality (augmented reality, AR) glasses, an AR helmet, virtual Reality (VR) glasses, or a VR helmet, and the wireless charging device may be any electronic device capable of providing wireless charging, such as a charging base, a glasses case for wirelessly charging VR glasses, a headset case for wirelessly charging headphones, a vehicle-mounted charger, and the like, which are not limited herein.

Hereinafter, a mobile phone is taken as an example of an electronic device, a charging base is taken as an example of a wireless charging device, and a technical scheme of the embodiment of the application is introduced.

For ease of understanding, first, a schematic view of a scenario in which the wireless charging device 20 provided in the embodiment of the present application performs wireless charging on the electronic device 10 will be described with reference to fig. 1A and 1B. In the scenario shown in fig. 1A and 1B, the electronic device 10 is not sleeved with a protective case. Fig. 1A is a schematic diagram showing a matching relationship between the wireless charging device 20 and the electronic device 10, and fig. 1B is a schematic circuit diagram showing that the wireless charging device 20 charges the electronic device 10 wirelessly. In the figures herein, the X-axis direction is the mating direction of the wireless charging device 20 when charging the electronic device 10, and is not individually emphasized in the following.

Referring to fig. 1A, when the wireless charging device 20 wirelessly charges the electronic device 10, the electronic device 10 may be placed above the wireless charging device 20 in the X-axis direction (as a first direction). It is understood that the wireless charging device 20 is provided with a transmitting coil 211 (as a third coil), and the electronic device 10 is provided with a receiving coil 111 (as a first coil). By coupling between the transmitting coil 211 and the receiving coil 111, the power in the transmitting coil 211 can be transmitted to the receiving coil 111, thereby transmitting the power in the wireless charging device 20 to the electronic device 10.

Illustratively, the electronic device 10 includes a housing 11 with a receiving coil 111 disposed in the housing 11. The wireless charging device 20 includes a housing 21, and a transmitting coil 211 is provided in the housing 211. When the wireless charging device 20 wirelessly charges the electronic device 10, the housing 11 is located above the housing 211 and both may be in contact with each other. At this time, the receiving coil 111 is located above the transmitting coil 211, and the distance between the receiving coil 111 and the transmitting coil 211 is LA (as a third distance), so that the transmitting coil 211 can wirelessly charge the receiving coil 111, that is, the wireless charging device 20 wirelessly charges the electronic device 10.

Illustratively, referring to fig. 1B, a transmitting circuit may be included in the wireless charging device 20 (i.e., TX end), and the transmitting circuit may include an oscillating circuit 1 formed by a transmitting coil 211, a capacitor 212 and a TX chip connected in series with each other. In addition, the transmitting circuit may further include a BOOST circuit and a power supply input port connected to the TX chip. The power supply input port is used for being connected with an external power supply to supply power, the BOOST circuit is used for converting the electric energy from the external power supply into the electric energy which can be received by the TX chip, and the TX chip is used for receiving the electric energy from the BOOST and supplying power to the oscillating circuit 1. When the oscillating circuit 1 is supplied with power, an oscillating current can be generated in the coil 211 and an alternating magnetic field can be generated in space.

The electronic device 10 (i.e., RX end) may include a receiving circuit, which may include an oscillating circuit 2 formed by a receiving coil 111, a capacitor 112, and an RX chip connected in series with each other. In addition, the transmitting circuit may further include a charger chip and a battery connected to the RX chip. The receive coil 111 is configured to couple with the transmit coil 211. That is, the receiving coil 111 is positioned in the alternating magnetic field generated by the transmitting coil 211, so that an oscillating current can be formed in the oscillating circuit 2. The charger chip is configured to receive the oscillating current from the oscillating circuit 2 and to convert the received oscillating current into an electrical energy output that can be received by a battery, the battery being configured to receive and store the electrical energy output by the charger chip.

It is to be understood that fig. 1B is merely an exemplary configuration of a transmitting circuit and a receiving circuit. The present application is not limited thereto. In other examples, the transmit circuit may not include a BOOST circuit and a supply input port. For example, the TX chip of the transmitting circuit may not be connected to an external power source, but to a power supply battery inside the wireless charging device 20 to be powered by the power supply battery. As another example, the receiving circuit may not include a charger chip. For example, the RX chip of the receiving circuit may be directly connected to the battery, and the electrical energy output by the RX chip can be received and stored by the battery.

It will be appreciated that the distance LA between the transmit coil 211 and the receive coil 111 may be determined based on the actual distance of the coil disposed to the surface of the housing in the X-axis direction. For example, the distance from the transmitting coil 211 to the outer surface of the housing 21 is A1, the distance from the receiving coil 111 to the outer surface of the housing 11 is A2, the sum of A1 and A2 is the distance LA between the transmitting coil 211 and the receiving coil 111 when wireless charging, and the distance A1 and A2 can be adaptively adjusted according to actual requirements, and are not particularly limited.

In other examples, the transmitting coil 211 may be provided on the outer surface of the housing 21, or the receiving coil 111 may be provided on the outer surface of the housing 11. Alternatively, in the wireless charging, the housing 11 may not be in contact with the housing 21, for example, the housing 11 may be supported above the housing 21 by a support member, so long as the transmitting coil 211 and the receiving coil 111 can be coupled to enable the wireless charging device 20 to wirelessly charge the electronic device 10, and the method is not particularly limited.

Fig. 1C shows an exemplary circuit diagram of the coupling of the transmit coil 211 and the receive coil 111. Referring to fig. 1C, during wireless charging, the receiving coil 111 is coupled to the transmitting coil 211, and the charging efficiency η1 (i.e., the first efficiency) between the two coils can be calculated by the following formula (1):

Where M represents the mutual inductance between the receiving coil 111 and the transmitting coil 211,v1 is the equivalent input voltage of the oscillating circuit 1 in the TX end, L1 is the inductance value of the transmitting coil 211, C1 is the capacitance of the capacitor 212 in the oscillating circuit 1The value R1 is the equivalent series resistance (equivalent series resistance, ESR) of the oscillating circuit 1. L3 is the inductance value of the receiving coil 111 in the RX end, C3 is the capacitance value of the capacitor 112 in the oscillating circuit 2, R3 is the ESR of the oscillating circuit 2 in the RX end, RL is the equivalent impedance of the load required by the system formed by coupling the oscillating circuit 2 and the oscillating circuit 1, and the RL value is different along with the change of the load. k is a coupling coefficient, and the value of k is related to the distance LA between the transmitting coil 211 and the receiving coil 111, and the smaller the distance LA is, the larger k is and the higher efficiency is.

It will be appreciated that the charging efficiency is associated with the distance LA between the transmit coil 211 and the receive coil 111 when the wireless charging device 20 charges the electronic device 10. The greater the distance LA of the receiving coil 111 from the transmitting coil 211, the lower the efficiency.

A schematic view of a scenario in which a wireless charging device is used to wirelessly charge an electronic device sleeved with a protective case according to some embodiments is described below with reference to fig. 2A and 2B. Fig. 2A is a schematic diagram showing a matching relationship between a wireless charging device and an electronic device sleeved with a protective shell, and fig. 2B is a schematic circuit diagram showing the wireless charging device to wirelessly charge the electronic device sleeved with the protective shell.

Referring to fig. 2A and 2B, when the electronic device 10 is sleeved with the protective case 30', a portion of the protective case 30' (specifically, a case wall 31 'of the protective case 30') is located between the case 11 and the case 21, that is, two opposite side surfaces of the case wall 31 'of the protective case 30' in the X-axis direction are respectively bonded to the surface of the case 21 and the surface of the case 11, and at this time, the distance between the transmitting coil 211 and the receiving coil 111 increases from the original LA to LB. It will be appreciated that the difference between LB and LA is the thickness of the shell wall 31' of the containment vessel 30' (the dimension of the shell wall 31' in the X direction). In view of the above, the increase of the distance between the coils can cause a partial loss of the transmitting coil 211 and the receiving coil 111 in the process of power transmission, and further reduce the wireless charging efficiency of the transmitting coil 211 to the receiving coil 111, and even fail to realize wireless charging.

Therefore, the embodiment of the application provides a protective housing, which can also ensure the charging efficiency of wireless charging equipment to electronic equipment in a state that the protective housing is sleeved on the electronic equipment. Specifically, be equipped with wireless coil in the protective housing, when electronic equipment carries out wireless charging under the state of cover establishes the protective housing, the transmitting coil in the wireless charging equipment can charge to the wireless coil in the protective housing earlier. The wireless coil in the protective shell charges the receiving coil in the electronic device after receiving the electric energy from the wireless charging device, so that the electronic device indirectly receives the wireless charging from the wireless charging device. That is, in the process that the wireless charging device performs wireless charging to the electronic device, the wireless coil in the protective housing may perform a relay function of energy transmission (therefore, the wireless coil in the protective housing may also be referred to as a "relay coil"), thereby improving charging efficiency that the wireless charging device performs wireless charging to the electronic device.

An exemplary structure of the protective case provided in the present application is described below with reference to fig. 3 to 5.

Fig. 3 is a schematic view of a scenario in which the wireless charging device 20 performs wireless charging on the electronic device 10 when the electronic device 10 is sleeved with the protective case 30 according to the embodiment of the present application. Fig. 4 shows a schematic circuit configuration in the protective case 30. Fig. 5 shows an exemplary schematic diagram of coupling the transmit coil 211, the relay coil 311, and the receive coil 111.

Referring to fig. 3 to 5, the wireless charging system includes a wireless charging device 20, an electronic device 10, and a protective case 30, where the protective case 30 is sleeved on the electronic device 10, and is used for protecting the electronic device 10. When the protective case 30 is sleeved on the electronic device 10, at least part of the protective case 30 is located between the wireless charging device 20 and the electronic device 10 in the X-axis direction. Illustratively, the housing wall 31 of the protective housing 30 is located between the wireless charging device 20 and the electronic device 10. At this time, the relay coil 311 (as the second coil) of the protective case 30 can receive the wireless power supply from the transmitting coil 211, and can wirelessly charge the receiving coil 111. That is, the transmitting coil 211 may indirectly perform wireless charging on the receiving coil 111 through the relay coil 311, so that the electronic device 10 indirectly receives wireless charging from the wireless charging device 20, thereby improving charging efficiency of the wireless charging device 20 to perform wireless charging on the electronic device 10.

Referring to fig. 3, the protective case 30 may further include a rim 32 connected to the case wall 31, the rim 32 being located at a circumferential side of the case wall 31 to form a receiving chamber for receiving the electronic device 10 such that a side of the case wall 31 facing the receiving chamber is in contact with the case 11, and the relay coil 311 is disposed inside the case wall 31.

For example, when the wireless charging device 20 wirelessly charges the electronic device 10 in which the protective case 30 is housed, the electronic device 10 in which the protective case 30 is housed may be placed above the wireless charging device 20 in the X-axis direction (as the first direction), the case wall 31 is located between the case 11 and the case 21, and both surfaces of the case wall 31 opposite to each other in the X-axis direction are in contact with the case 11 and the case 21, respectively. At this time, the distance between the transmitting coil 211 and the receiving coil 111 increases from LA to LB, and the increased distance is the thickness of the case wall 31 (the dimension of the case wall 31 in the X direction). Since the relay coil 311 is disposed between the transmitting coil 211 and the receiving coil 111, the relay coil 311 can be coupled with the transmitting coil 211 and the receiving coil 111, respectively, so that the transmitting coil 211 charges the relay coil 311 first, and then the relay coil 311 supplies the power from the transmitting coil 211 to the receiving coil 111, that is, the transmitting coil 211 charges the receiving coil 111 indirectly through the relay coil 311, which may also be understood as that the wireless charging device 20 charges the electronic device 10 wirelessly indirectly.

Illustratively, the distance between the transmitting coil 211 and the relay coil 311 is LC (as the second distance), the distance between the receiving coil 111 and the relay coil 311 is LD (as the first distance), and the sum of LD and LC is LB.

Illustratively, LC < LA, LD < LA. In this way, the charging efficiency of the transmitting coil 211 when wirelessly charging the relay coil 311 may be greater than the charging efficiency of the transmitting coil 211 when directly charging the receiving coil 111, and the charging efficiency of the relay coil 311 when wirelessly charging the receiving coil 111 may be greater than the charging efficiency of the transmitting coil 211 when directly charging the receiving coil 111. Thus, the charging efficiency of the transmitting coil 211 to wirelessly charge the receiving coil 111 through the relay coil 311 (i.e., the charging efficiency of the transmitting coil 211 to indirectly charge the receiving coil 111 as the second efficiency) may be higher than the charging efficiency of the transmitting coil 211 to directly wirelessly charge the receiving coil 111 (as the first efficiency).

In other examples, only one of the LC and the LD may be set to a value smaller than LA, as long as it can be ensured that the charging efficiency of the wireless charging device 20 for wirelessly charging the electronic device 10 in which the protective case 30 is sleeved is higher than the charging efficiency of the wireless charging device 20 for wirelessly charging the electronic device 10 in which the protective case 30 is not sleeved, without being particularly limited.

In other examples, specific values of LC, LD may be determined according to actual requirements. For example, lc++ld may be set, or lc++ld may be set, and adaptive adjustment may be performed according to actual needs, without specific limitation. In this example, LC+.LD.

In other examples, the protective case 30 is provided as a plastic piece, and the protective case 30 may be injection molded. In order to secure the stability of the relay coil 311 in the protective case 30, the relay coil 311 may be placed in an injection cavity corresponding to an injection mold for molding the protective case 30 in advance to dispose the relay coil 311 inside the protective case 30, for example, the relay coil 311 inside the case wall 31 of the protective case 30. In addition, the thickness of the relay coil 311 (i.e., the dimension of the relay coil 311 in the X-direction) may be not greater than the thickness of the case wall 31, so that the total thickness of the protective case 30 may not be increased after the relay coil 311 is disposed.

Referring to fig. 4, the protective case 30 may include therein a relay circuit, which may include an oscillation circuit 3 formed by a relay coil 311 and a capacitor 312 connected in series with each other. In the oscillating circuit 3, L2 is the inductance value of the relay coil 311, C2 is the capacitance value of the capacitor 312, and R2 is the ESR in the oscillating circuit 3.

Further, by setting the capacitance value of the capacitor 312, it is possible to make the charging efficiency η2 (i.e., the second efficiency) of the transmitting coil 211 for indirectly charging the receiving coil 111 through the relay coil 311 higher than the charging efficiency η1 of the transmitting coil 211 for directly charging the receiving coil 111 during wireless charging.

Illustratively, referring to fig. 5, in wireless charging, the transmitting coil 211 of the transmitting circuit, the relay coil 311 of the relay circuit, and the receiving coil 111 of the receiving circuit are coupled to each other, and the charging efficiency η2 of the transmitting coil 211 for indirectly charging the receiving coil 111 through the relay coil 311 can be calculated by the following formula (2):

η2＝A0/A1 (2)

wherein a0=r _L [(-w ² M ₁₂ M ₂₃ +wX ₂ M ₁₃ ) ² +(wM ₁₃ R ₂ ) ² ]，

A1＝

[(-w ² M ₁₂ M ₂₃ +wX ₂ M ₁₃ ) ² +(wM ₁₃ R ₂ ) ² ](R _L +R ₃ )+R ₁ {[X ₂ (R _L +R ₃ )+X ₃ R ₂ ] ² +[-X ₂ X ₃ +R ₂ (R _L +R ₃ )+w ² M ₂₃ ² ] ² }+R ₂ [(-w ² M ₁₃ M ₂₃ +wX ₃ M ₁₂ ) ² +(wM ₁₂ (R _L +R ₃ )) ² ]，

Wherein w=i×pi×f, pi is a circumference ratio;

wherein V1 is an equivalent input voltage of the oscillating circuit 1 in the TX end, L1 is an inductance value of the transmitting coil 211, C1 is a capacitance value of the capacitor 212 in the oscillating circuit 1, and R1 is an ESR of the oscillating circuit 1; l3 is the inductance value of the receiving coil 111 at the RX end, C3 is the capacitance value of the capacitor 112 of the oscillating circuit 1 at the RX end, R3 is the ESR of the oscillating circuit 2 at the RX end, RL is the equivalent impedance of the load required by the system formed by coupling the oscillating circuit 2 with the oscillating circuit 1 and the oscillating circuit 3, and the RL value is different along with the change of the load. L2 is the inductance value of the relay coil 311, C2 is the capacitance value of the capacitor 312 in the oscillating circuit 3, and R2 is the ESR of the oscillating circuit 3 in the relay coil 311.

In the transmitting coil 211, the relay coil 311, and the receiving coil 111, mutual inductance exists between each of the two coils.

Where M12 represents the mutual inductance between the transmitting coil 211 and the relay coil 311,k12 is the coupling coefficient of the transmitting coil 211 and the relay coil 311;

m13 represents the mutual inductance between the transmitting coil 211 and the receiving coil 111,k13 is the coupling coefficient of the transmitting coil 211 and the receiving coil 111;

m23 represents the mutual inductance between the relay coil 311 and the receiving coil 111,k23 is a coupling coefficient of the relay coil 311 and the receiving coil 111.

In the above formula, the inductance value L2 of the relay coil 311 is determined by the number of turns and the area of the relay coil 311, and C2 can select a suitable capacitance value as a preset capacitance value according to the requirement. In order to ensure better charging efficiency, the relay coil 311 is configured to match the transmitting coil 211 and the receiving coil 111, for example, the coil materials, the coil numbers, the coil shapes, the coil areas, etc. of the relay coil 311 and the transmitting coil 211 are equal or substantially equal, and/or the coil materials, the coil numbers, the coil shapes, the coil areas, etc. of the relay coil 311 and the receiving coil 111 are equal or substantially equal.

Referring to fig. 3, when the wireless charging device 20 performs wireless charging to the electronic device 10 in which the protective case 30 is sleeved, the relay coil 311 is matched with the transmitting coil 211 and the receiving coil 111 without change, so that the inductance value L1 of the transmitting coil 211, the inductance value L2 of the relay coil 311, and the inductance value L3 of the receiving coil 111 are fixed. The distances between the transmitting coil 211, the intermediate coil 311 and the receiving coil 111 do not change, so k12, k13, k23 are also fixed. The corresponding transmitting circuit, relay circuit and receiving circuit are unchanged when the transmitting coil 211, the intermediate coil 311 and the receiving coil 111 are coupled, the ESR in each circuit is unchanged, and the R1, R2, R3, RL and the operating frequency f are fixed. Therefore, the above formula arrangement finds that, except for the fixed part, the charging efficiency η2 is related to only C1, C2, C3.

In addition, during wireless charging, the capacitance value C1 of the capacitor 212 in the transmitting circuit and the capacitance value C3 of the capacitor 112 in the receiving circuit are fixed values set in advance, and if the charging efficiency η2 is to be improved, this can be achieved by adjusting the capacitance value C2 of the capacitor 312 in the relay circuit.

Taking the following example of setting the coil numbers of the transmitting coil 211, the relay coil 311, and the receiving coil 111 to 8 turns, according to the scenario in fig. 3 in which the wireless charging device 20 performs wireless charging to the electronic device 10 in which the protective case 30 is sleeved, the following exemplary data are obtained:

TABLE 1

L1(μH)	12.378
		L2(μH)	5.0248
L3(μH)	5.8212
		k12	0.74682
k23	0.865919
		k13	0.660717
R1(mohm)	105
		R2(mohm)	141
R3(mohm)	140

Fig. 6 shows a correspondence relationship between the capacitance value C2 of the capacitor 312 and the charging efficiency η2, wherein the abscissa is the capacitance value C2 (unit: nF) and the ordinate is the charging efficiency η2. Referring to fig. 6, based on the data given in table 1, the data in table 1 is brought into formula (2) and a plurality of capacitance values C2 of the capacitor 312 in the range of 0nF-250nF are selected for calculation, respectively, to obtain a plurality of groups of different charging efficiencies η2. As can be seen from the figure, when different capacitance values C2 are selected, the obtained charging efficiency η2 varies significantly. Among the efficiency η2 data obtained in the selected 0nF-250nF range, it is found that the charging efficiency η2 has a maximum value. When the charging efficiency η2 takes the maximum value, the capacitance value c2=30nf of the corresponding capacitor 312.

Taking an example in which the external power supply supplies power to the wireless charging device 20 at 30W (10V 3A) during wireless charging, in the scenario of fig. 1A, when the wireless charging device 20 wirelessly charges the electronic device 10 without the protective case 30, the charging efficiency η1 calculated according to the formula (1) is 93.28%. In the scenario of fig. 3, when the wireless charging device 20 wirelessly charges the electronic device 10 in which the protective case 30 is sleeved, the capacitance value C2 of the capacitor 312 in the relay circuit is set to 30nF, and the charging efficiency η2 calculated according to the formula (2) is 94.07%. It can be seen that by setting the capacitance value C2 of the capacitor 312, for example, when the capacitance value C2 of the capacitor 312 is set to 30nF (as a preset capacitance value), the charging efficiency η2 is higher than the charging efficiency η1.

It will be appreciated that the capacitance value of the capacitor 312 may be set to be adjustable, so as to adaptively adjust the capacitance value C2 of the capacitor 312 according to different situations, so as to ensure that the charging efficiency can be improved when the wireless charging device 20 wirelessly charges the electronic device 10 with the protective case 30 sleeved thereon, and the specific adjustment value of the capacitance value C2 of the capacitor 312 may be adaptively adjusted according to the above formula (2), which is not limited specifically.

An exemplary structure of the relay coil 311 and the capacitor 312 in the protective case 30 provided in the present application is described below with reference to fig. 7A to 8.

Fig. 7A and 7B show an exemplary structure of the relay coil 311 in the protective case 30. Fig. 7C shows an exemplary structure in which the relay coil 311 in the protective case 30 is connected to the capacitor 312. Fig. 7D shows an exemplary structure of each lamination of the relay coil 311 in the protective case 30.

Referring to fig. 7A and 7B, a circuit board 31a is provided in a case wall 31 of the protective case 30. In some examples, the circuit board 31a may be a flexible circuit board (flexible printed circuit, FPC) to facilitate increasing the overall flexibility of the protective case 30 such that the protective case 30 is more easily sleeved over the electronic device 10. In other examples, the circuit board 31a may also be a rigid printed circuit board (printed circuit board, PCB).

Referring to fig. 7C and 7D, the circuit board 31a may include an insulating layer 311a and metal coils 311b located at both sides of the insulating layer 311a, the outer surfaces of the metal coils 311b being covered with an insulating layer 311D, the metal coils 311b located at both sides of the insulating layer 311a being electrically connected. The circuit board 31a may further include a conductive body 311f and a connection layer 311c between the metal coil 311b and the insulating layer 311d, the connection layer 311c being in contact with the surface of the metal coil 311b. The connection layer 311c is a conductive layer for electrically connecting the metal coils 311b on both sides of the insulation layer 311 a. An adhesive layer 311e is provided between the connection layer 311c and the insulating layer 311d, and the adhesive layer 311e is used for adhering and fixing the insulating layer 311d. It is understood that, along the X-axis direction, at least the insulating layer 311a is provided with a through hole 1a ', the conductive body 311f may be a conductive tube penetrating through the through hole 1a', and two ends of the conductive tube are respectively used for connecting the connecting layers 311c on two sides. The connection layer may be a conductive layer.

Referring to fig. 7C, in preparing the circuit board 31a, it is possible to select the insulating layer 311a as a substrate, prepare the metal coil 311b, the connection layer 311C, the adhesive layer 311e, and the insulating layer 311d in this order on both sides in the thickness direction (X-axis direction) of the substrate, and prepare the through hole 1a 'on the insulating layer 311a so that the conductor 311f can be directly connected to the connection layer 311C by penetrating through the through hole 1 a'. Alternatively, two metal coils 311b may be connected to both ends of the conductor 311f, respectively, and the metal coils 311b may be in contact with the connection layer 311c, that is, the conductor 311f may be indirectly connected to the connection layer.

The edge of the insulating layer 311d does not entirely cover the connection layer 311c when viewed in the thickness direction, and the connection layer 311c is partially exposed. The exposed portion of the connection layer 311c may be connected to a pad 313 (as a first pad) through a lead 313a (as a first lead), and to a pad 314 (as a second pad) through a lead 314a (as a second lead), for electrical connection with the positive and negative electrodes of the capacitor 312, respectively. The capacitor 312 is bridged between the two bonding pads, which is beneficial to the thickness reduction of the whole thickness of the capacitor 312 and the relay coil 311 in the X-axis direction, so that the thinning of the protective housing 30 is beneficial when the relay coil 311 and the capacitor 312 are arranged in the protective housing 30.

Referring to fig. 7D, the circuit board 31a may form a metal coil 311b, a connection layer 311c, an adhesive layer 311e, and an insulation layer 311D, which are sequentially stacked, on both sides of the insulation layer 311a, respectively, using a patterning process. Wherein, when patterning the connection layer 311c, the connection layer 311c and the conductor 311f may be molded together to form a through-hole in-line element (plating through hole, PTH). It will be appreciated that the electroless plating is performed on the inner side wall of the through-hole 1a ' such that a tubular conductive body 311f (i.e., a conductive tube) is formed in the through-hole 1a ', and a portion of the electroless plated material is caused to protrude out of the through-hole 1a ' to form the connection layer 311c.

It is understood that the conductor 311f may be made of the same material as the metal coil 311b, for example, the material of the conductor 311f is copper, and the connection layer 311c patterned together with the conductor 311f is also a copper layer. Specific implementation manners of forming the PTH by adopting the chemical plating can refer to the manufacturing process of the circuit board, and will not be repeated.

In addition, the surface flatness and smoothness of the connection layer 311c are higher than those of the metal coil 311 b.

In other examples, the material of the conductive body 311f and the connection layer 311c may be other materials capable of conducting electricity, such as aluminum, copper alloy, and the like. The material of the conductor 311f and the connection layer 311c may be selected from materials different from those of the metal coil 311b, and is not particularly limited.

It is to be understood that the connection layer 311c and the conductor 311f may be formed separately, and are not particularly limited.

In other examples, fig. 7D is only an exemplary structure of lamination in the relay coil 311, to which the present application is not limited. For example, in the structure shown in fig. 7D, the circuit board 31a includes two connection layers 311c, and the connection layers 311c are located between the metal coil 311b and the insulating layer 311D. In other examples, the connection layer 311c may not be included in the circuit board 31a, but the metal coil 311b and the insulating layer 311d may be connected by the adhesive layer 311e, and the conductor 311f may be directly electrically connected to the metal coil 311b. As another example, in the structure shown in fig. 7D, the circuit board 31a includes two layers of metal coils 311b. In other examples, more than 3 layers of metal coils 311b may be included in the circuit board 31a, e.g., 5 layers, 8 layers, etc. Therefore, in this example, the relay coil 311 may be formed of a greater number of layers of the metal coils 311b, without being particularly limited.

In some examples, the adhesive layer 311e may be a double-sided adhesive, a pressure-sensitive adhesive, or the like, without being particularly limited.

In some examples, the metal coil 311b may be directly prepared on the circuit board 31a by punching or laser to form the relay coil 311, which is not particularly limited. In some examples, the metal coil 311b may be made of copper, copper alloy, aluminum alloy, or the like, without being particularly limited.

In some examples, the insulating layer 311a and/or the insulating layer 311d may be made of Polyimide (PI) material, which is not particularly limited.

In the example shown in fig. 7C and 7D, the relay coil 311 is formed on the circuit board 31a, enabling the relay coil 311 to have a compact structure. For example, referring to fig. 7A and 7B, the circuit board 31a is formed inside the case wall 31, and the thickness of the circuit board 31a is smaller than the thickness of the case wall 31, so that the thickness of the protective case 30 is not increased after the relay coil 311 is added, and thus the distance between the transmitting coil 211 in the wireless charging device 20 and the receiving coil 111 in the electronic device 10 is not increased, which is advantageous for improving the wireless charging efficiency.

In other examples, the relay coil 311 may be formed in other manners, for example, by winding an enamel wire, which is not particularly limited in this application.

Fig. 8 illustrates an exemplary formation of the transmit coil 211. Referring to fig. 8, the transmitting coil 211 may be formed on the circuit board 21b, similar to the relay coil 311. Specifically, the circuit board 21b includes an insulating layer 211d, an adhesive layer 211c, a metal coil 211b, an insulating layer 211a, a metal coil 211b, an adhesive layer 211c, and an insulating layer 211d, which are stacked in this order. The two layers of metal coils 211b are electrically connected to form together the transmitting coil 211. The insulating layer 211d, the adhesive layer 211c, the metal coil 211b, and the insulating layer 211a may be disposed in the same manner as the insulating layer 311d, the adhesive layer 311c, the metal coil 311b, and the insulating layer 311a of the circuit board 31b, respectively, and are not described in detail. The insulating layer 211d, the adhesive layer 211c, the metal coil 211b, and the insulating layer 211a collectively form the emitting portion U of the circuit board 21 b.

Unlike the circuit board 31b, the circuit board 21b further includes a blocking portion S. The blocking portion S includes an insulating layer 211h, at least one nanocrystal layer 211i, and an insulating layer 211j, which are stacked in the thickness direction. The insulating layer 211h is connected to the insulating layer 211d of the emission portion U through an adhesive layer 211g, and when the nanocrystal layers 211i are provided in multiple layers, adjacent nanocrystal layers 211i can be connected through an adhesive layer.

The blocking portion S is located below the transmitting portion U in the thickness direction, which is located on the side of the circuit board 21b facing the receiving coil 111, for causing the transmitting coil 211 to generate electric power and output the electric power, and the blocking portion S is used to limit the direction in which the electric power of the transmitting coil 211 is output (i.e., limit the downward output of the electric power of the transmitting coil 211) so that the energy of the transmitting coil 211 is output to the receiving coil 111 and/or the relay coil 311 as much as possible.

In contrast, referring to fig. 7D, for the relay coil 311, since it is required to implement double-sided transmission of energy, that is, to receive energy from the transmitting coil 211 located below and to transmit energy to the receiving coil 111 located above, the relay coil 311 may not be provided with a nanocrystal layer to ensure smooth transmission of energy.

It will be appreciated that the structure of the receiving coil 111 may be the same or substantially the same as that of the transmitting coil 211, i.e., the receiving coil 111 may adopt the exemplary structure of fig. 8, and will not be described again.

Exemplary shapes of the relay coil 311, the transmission coil 211, and the reception coil 111 are described below in connection with fig. 9A to 9C. Fig. 9A to 9C are plan views (views in the vertical X-axis direction) of the relay coil 311, the transmitting coil 211, and the receiving coil 111. The Y-axis direction (as the second direction) may be the length direction or the width direction of the protective case 30, that is, the Y-axis direction is perpendicular to the X-axis direction, and is not emphasized separately in the following.

Fig. 9A and 9B show an exemplary structure in which the relay coil 311, the transmission coil 211, and the reception coil 111 are mated. Referring to fig. 9A and 9B, the relay coil 311, the transmitting coil 211, and the receiving coil 111 are each of a circular structure, and the shapes of the relay coil 311, the transmitting coil 211, and the receiving coil 111 are matched. For example, the diameter of the receiving coil 111 is P1, the diameter of the relay coil 311 is P3, and the diameter of the transmitting coil 211 is P2. Wherein, P1, P2, P3 may be equal, or the deviation between P1, P2, P3 is smaller than a set value, for example, smaller than 5%.

In other examples, fig. 9A and 9B are merely exemplary shapes of the relay coil 311, the transmitting coil 211, and the receiving coil 111, and the present application is not limited thereto. For example, referring to fig. 9C, the relay coil 311, the transmitting coil 211, and the receiving coil 111 may also be provided in a square structure, without being particularly limited.

It will be appreciated that to improve the efficiency of energy transfer between coils, it is desirable that the two coils coupled to each other be as aligned as possible. For example, referring to fig. 9A, when the electronic device 10 is not sleeved with the protective case 30 and the transmitting coil 211 directly charges the receiving coil 111, in order to ensure charging efficiency, the transmitting coil 211 and the receiving coil 111 need to have high alignment accuracy, for example, a distance between a center W2 of the transmitting coil 211 and a center W1 of the receiving coil 111 in the Y direction needs to be less than R1. Generally, R1 is about 1.5mm to 2.5 mm. That is, when the electronic device 10 is directly wirelessly charged through the wireless charging device 30, the electronic device 10 and the wireless charging device 20 need to be strictly aligned, which increases the difficulty of the user's operation.

By sleeving the protective case 30 provided in the embodiment of the present application on the electronic device 10, referring to fig. 9B, in order to satisfy the charging efficiency, it is only necessary to keep the distance between the center W3 of the relay coil 311 and the center W1 of the receiving coil 111 below R1, and keep the distance between the center W2 of the transmitting coil 211 and the center W3 of the relay coil 311 below R1. That is, by attaching the protective case 30 to the electronic device 10, the accuracy of alignment between the electronic device 10 and the wireless charging device 20 can be widened from R1 to 2×r1 (i.e., about 3mm to 5 mm) when wireless charging is performed, thereby reducing the difficulty of user operation.

The application still provides a wireless charging system, wireless charging system includes wireless charging equipment, electronic equipment and protective housing, and the protective housing cover is located on the electronic equipment, and the protective housing is the protective housing that describes in above-mentioned each embodiment, and wireless charging equipment includes transmitting coil, and electronic equipment includes receiving coil, and when electronic equipment was located to the protective housing cover, relay coil can receive rather than the wireless power supply of transmitting coil that has the second distance, and can carry out wireless charging to receiving coil. The beneficial effects that wireless charging system can reach can refer to the beneficial effects of protective housing, and not repeated.

It will be appreciated that in other examples, the wireless charging system may not include a wireless charging device, and is not specifically limited.

It should be noted that, directional terms such as "upper", "lower", "left", "right", "front", "rear", "top", "bottom" and the like herein are exemplary orientations based on the drawings, and do not indicate or imply that the components referred to must have a specific orientation, which may be changed according to actual use, and are not to be construed as limiting the present application.

In the above description of the present embodiment, unless otherwise indicated, "/" means or, for example, a/B may identify a or B; the term "and/or" herein is merely an association relation describing an association object, and means that three kinds of relations may exist, for example, a and/or B may mean that three kinds of cases of a alone, B alone, a and B simultaneously exist.

Claims

1. A protective shell is used for being sleeved on first electronic equipment, the first electronic equipment comprises a first coil, and the protective shell comprises a second coil; wherein,

when the protective shell is sleeved on the first electronic device, the second coil can receive wireless power supply of a third coil in the second electronic device and can wirelessly charge the first coil.

2. The protective case of claim 1, wherein the second coil is a first distance from the first coil when the protective case is sleeved on the first electronic device, the second coil being capable of being a second distance from the third coil such that the third coil is capable of wirelessly charging the first coil through the second coil;

when the protective shell is not sleeved on the first electronic device, the first coil can have a third distance from the third coil, so that the third coil can wirelessly charge the first coil;

wherein the third distance is greater than the first distance and greater than the second distance.

3. The protective case of claim 1 or 2, wherein the third coil is capable of wirelessly charging the first coil with a first efficiency when the protective case is not sleeved on the first electronic device;

When the protective shell is sleeved on the first electronic device, the third coil can wirelessly charge the first coil through the second coil with second efficiency;

wherein the second efficiency is higher than the first efficiency.

4. A protective case according to claim 3, wherein the protective case comprises a capacitor, the capacitor and the second coil together forming an oscillating circuit capable of generating an oscillating current in the second coil; the capacitor has a preset capacitance value, and the capacitance value enables the second efficiency to be higher than the first efficiency.

5. The protective case of claim 4, wherein the capacitor is a capacitance-adjustable capacitor.

6. The protective case of claim 1, including a circuit board disposed within the protective case, the circuit board including a plurality of layers of metal coils disposed in a stacked arrangement, the plurality of layers of metal coils being electrically connected to one another to form the second coil.

7. The protective case of claim 6, wherein the circuit board further comprises an insulating layer disposed between two adjacent layers of the metal coil.

8. The protective case of claim 7, wherein a via is provided in the insulating layer, and a conductor connecting two adjacent layers of the metal coil is provided in the via.

9. The protective case of claim 6, wherein the circuit board has a first pad and a second pad on a surface thereof, the circuit board includes a first lead and a second lead, one end of the second coil is electrically connected to the first pad through the first lead, and the other end is electrically connected to the second pad through the second lead;

the protective housing includes a capacitor, the capacitor and the second coil together forming an oscillating circuit capable of generating an oscillating current in the second coil, the positive and negative electrodes of the capacitor being soldered to the first and second pads, respectively.

10. The protective case of claim 9, wherein the capacitor is disposed in a wall of the protective case.

11. A wireless charging system comprising a first electronic device and the protective case of any one of claims 1 to 10, the protective case being adapted to fit over the first electronic device, the first electronic device comprising a first coil; wherein,

When the protective shell is sleeved on the first electronic device, the second coil can receive wireless power supply of a third coil in the second electronic device, and can wirelessly charge the first coil.

12. A wireless charging system comprising a first electronic device, a second electronic device and the protective case of any one of claims 1 to 10, the first electronic device comprising a first coil, the second electronic device comprising a third coil:

when the protection shell is sleeved on the first electronic device, the second coil can receive wireless power supply of the third coil and can wirelessly charge the first coil.

13. The wireless charging system of claim 12, wherein the first coil, the second coil, and the third coil are sequentially positionable along a first direction when the protective housing is positioned over the first electronic device, the center of the first coil and the center of the third coil being spaced apart from each other by a distance of 3mm to 5mm in a second direction, the second direction being perpendicular to the first direction.