Inductive charging coils on both sides

Abstract

A device for inductively charging an electronic accessory includes a first portion, a second portion, and a spacer. The first portion includes a first transmitting coil in a first plane, wherein the first transmitting coil is configured to generate a first magnetic field, and the second portion includes the first transmitting coil in a second plane, wherein the second transmitting coil is configured to generate a second magnetic field. The spacer is located between the first transmitting coil and the second transmitting coil and between the first plane and the second plane. The spacer material magnetically insulates the second transmitting coil from the first magnetic field.

Description

Background Art

[0001] Background and Related Technology

[0002] Electronic devices often utilize wireless accessory devices to allow users to provide input to or interact with the electronic device. Wireless accessory devices have batteries to power the accessory device during operation. Conventional systems for charging accessory devices include charging cables, inductive charging coils, or charging cradles. Each traditional charging system requires the user to place the accessory device in a specific location, on a specific stand, or take the additional step of plugging the device into a cable.

[0003] Inductive charging provides a current through a transmitting coil to generate a magnetic field. Exposing a second coil of conductive material to the magnetic field induces a current through a receiving coil to power an electronic device or charge a battery. Because power transfer via a magnetic field is related to the strength of the magnetic field, power transfer decreases rapidly (e.g., as the square of the distance). Therefore, efficient power transfer via a magnetic field requires that the transmitting coil and the receiving coil be as close to each other as possible.

[0004] Brief Overview

[0005] As described above, electronic devices often use wireless accessories. For example, a user may have a wireless keyboard for their computer. The user may wish to wirelessly charge the keyboard when it is mounted or attached to the computer in a number of different positions. In this example, the keyboard may be magnetically coupled to two or more different surfaces of the computer to facilitate use with the computer when the computer is in different orientations (e.g., a laptop orientation and a studio orientation). As described above, power transfer decreases rapidly with distance, so it is beneficial to have the charging coil close to the surface of the computer and keyboard at each charging position.

[0006] In one example, a computer includes two charging coils to facilitate charging near opposing surfaces of the computer (e.g., one coil near each surface). Magnetic coupling between coils in a computer (e.g., between transmitting coils) can result in power loss and potential damage to the charging circuitry. Thus, in this example, the coils are stacked with ferrite and non-magnetic material between the coils to inhibit coupling effects within the computer. These stacked coils allow for efficient charging of the keyboard when the keyboard is in two charging positions, thereby reducing the size of the coils and the power requirements of the coils.

[0007] In some embodiments, a device for inductively charging an electronic accessory includes a first portion, a second portion, and a spacer. The first portion includes a first transmitting coil in a first plane, wherein the first transmitting coil is configured to generate a first magnetic field, and the second portion includes a second transmitting coil in a second plane, wherein the second transmitting coil is configured to generate a second magnetic field. The spacer is located between the first transmitting coil and the second transmitting coil and between the first plane and the second plane. The spacer material magnetically insulates the second transmitting coil from the first magnetic field.

[0008] In some embodiments, a system for providing power to an accessory device from an electronic device includes a transmitter and a receiver. The transmitter includes a first portion, a second portion, and a spacer. The first portion includes a first transmitting coil in a first plane, wherein the first transmitting coil is configured to generate a first magnetic field, and the second portion includes the first transmitting coil in a second plane, wherein the second transmitting coil is configured to generate a second magnetic field. The spacer is located between the first transmitting coil and the second transmitting coil and between the first plane and the second plane. The spacer material magnetically insulates the second transmitting coil from the first magnetic field. The receiver includes a first portion, a second portion, and a spacer. The first portion includes a first receiving coil, wherein the first receiving coil is configured to generate a current when exposed to a magnetic field, and the second portion includes a second receiving coil, wherein the second receiving coil is configured to generate a current when exposed to a magnetic field. The spacer is located between the first receiving coil and the second receiving coil. The spacer material magnetically insulates the first receiving coil from the second receiving coil.

[0009] In some embodiments, a method of providing power to an accessory device from an electronic device includes providing a first interrogation current to a first transmitting coil proximate a first surface of the electronic device to generate a first magnetic field through the first transmitting coil, wherein a portion of the first magnetic field extends beyond the first surface; after terminating the first interrogation current to the first transmitting coil, providing a second interrogation current to a second transmitting coil proximate a second surface of the electronic device opposite to the first surface to generate a second magnetic field through the second transmitting coil, wherein a portion of the second magnetic field extends beyond the second surface; detecting an induced current in a receiving coil of the accessory device in response to one of the first magnetic field and the second magnetic field; and selectively providing a charging current to the first transmitting coil when the induced current is detected in response to the first magnetic field or providing a charging current to the second transmitting coil when the induced current is detected in response to the second magnetic field.

[0010] This Summary is provided to introduce a selection of concepts in a simplified form that are also described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0011] Additional features and advantages will be set forth in the following description, and in part will be apparent from the description, or may be learned by practicing the teachings herein. The features and advantages of the present disclosure may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. The features of the present disclosure will become more fully apparent from the following description and the appended claims, or may be learned by practicing the present disclosure as set forth below. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to describe the manner in which the above-listed and other features of the present disclosure can be obtained, a more specific description will be presented by reference to specific embodiments thereof illustrated in the accompanying drawings. For better understanding, the same elements have been designated by the same reference numerals throughout the various drawings. Although some of the drawings may be schematic or exaggerated representations of concepts, at least some of the drawings may be drawn to scale. It will be understood that the drawings depict some example embodiments, which will be described and explained with additional specificity and detail through the use of the drawings, in which:

[0013] Figure 1-1 is a perspective view of an accessory device in a first charging position with an electronic device according to at least one embodiment of the present disclosure;

[0014] Figure 1-2 is a perspective view of an accessory device in a second charging position with an electronic device according to at least one embodiment of the present disclosure;

[0015] Figure 2-1 is a cross-sectional side view of an accessory device in a first charging position with an electronic device according to at least one embodiment of the present disclosure;

[0016] Figure 2-2 is a perspective view of an accessory device in a second charging position with an electronic device according to at least one embodiment of the present disclosure;

[0017] Figure 3 is a plan view of a flexible printed circuit of a transmitter according to at least one embodiment of the present disclosure;

[0018] Figure 4 is a perspective view of an assembled transmitter according to at least one embodiment of the present disclosure;

[0019] Figure 5-1 is a side view of a transmitter generating a first magnetic field according to at least one embodiment of the present disclosure;

[0020] Figure 5-2 is a side view of a transmitter generating a second magnetic field according to at least one embodiment of the present disclosure;

[0021] Figure 6is a side view of a receiver according to at least one embodiment of the present disclosure;

[0022] Figure 7 is a side cross-sectional detail of a receiver and a transmitter in a first charging position according to at least one embodiment of the present disclosure;

[0023] Figure 8 is a perspective exploded view of a charging system having alignment features according to at least one embodiment of the present disclosure; and

[0024] Fig. 9 is a flowchart illustrating a method of wirelessly charging an accessory device from an electronic device according to at least one embodiment of the present disclosure. DETAILED DESCRIPTION

[0025] The present disclosure generally relates to devices, systems, and methods for providing power to an electronic accessory to power the electronic accessory and / or wirelessly charge a battery of the electronic accessory. In some embodiments, the electronic accessory is powered by an electronic device such as a laptop computer, a tablet computer, a hybrid computer, a smartphone, a smart television, other appliances, a motor vehicle (such as in a passenger compartment of a motor vehicle), or another electronic device. In some embodiments, wirelessly powering an accessory device includes positioning the accessory device in one of a plurality of positions relative to the electronic device.

[0026] Figure 1-1 1 shows a charging system 101 including an accessory device 100 and an electronic device 102 according to some embodiments. Figure 1-1 As shown, the user places the accessory device 100 in a charging position on the first surface 108 of the electronic device 102. The charging position can align the transmitting coil 104 of the electronic device 102 with the receiving coil 106 of the accessory device 100. When the electronic device 102 applies a charging current to the transmitting coil 104 of the conductive material in the electronic device, the transmitting coil 104 generates a magnetic field in a normal direction relative to the plane of the coil. When the receiving coil 106 of the conductive material is positioned in the magnetic field, the magnetic field induces an induced current in the receiving coil 106. The receiving coil 106 can then provide the induced current to power the accessory device 100 and / or charge the battery of the accessory device 100. In some embodiments, the accessory device 100 and the electronic device 102 utilize a near field communication (NFC) protocol to charge and / or communicate via the coils 104 and 106. In some embodiments, the accessory device 100 and the electronic device 102 utilize a Qi protocol to charge and / or communicate via the coils 104 and 106.

[0027] In some embodiments, when the accessory device 100 is in the charging position, the accessory device 100 blocks, obstructs, or otherwise prohibits use of a portion of the electronic device 102. In some embodiments, the electronic device 102 has a second charging position on an opposite second surface 110 of the electronic device 102, such as Figure 1-2 The user can place the accessory device 100 in a second charging position on the opposing second surface 110 to continue to wirelessly power the accessory device 100 without occupying the first surface 108 .

[0028] In some embodiments, the electronic device 102 has a transmitter that provides a magnetic field, and the accessory device 100 has a receiver that generates an induced current from the magnetic field. Conventional inductive charging coils may use a single transmitter coil in the electronic device and a receiver coil in the accessory, centered within the thickness of each device.

[0029] The wireless charging system according to the present disclosure provides advantages over conventional designs by operating by using at least two coils near an exterior surface in each device to thereby reduce the distance between the transmitter (Tx) and receiver (Rx) in both a first charging location and a second charging location on an opposing surface (e.g., an upper surface of a laptop and a lower surface of a laptop). Because magnetic field power decreases rapidly with increasing distance (e.g., decreases exponentially for increasing distance), increasing the distance between the transmitting coil and the receiving coil forces an associated increase in transmitting coil size and current. The reduced distance according to the present disclosure allows the wireless charging system to achieve power transfer rates equal to or greater than existing alternatives while occupying significantly less space in terms of length and width inside the product and consuming less power.

[0030] Now refer to Figure 2-1 According to some embodiments, an accessory device 200 (e.g., accessory device 100) is positioned on a first surface 208 of an electronic device 202 (e.g., electronic device 102). The electronic device 202 includes a transmitter 212 and the accessory device 200 includes a receiver 214. The transmitter 212 has a first transmitting coil 216-1 and a second transmitting coil 216-2, which are magnetically insulated from each other by a transmitter spacer 218. The receiver 214 has a first receiving coil 220-1 and a second receiving coil 220-2, which are magnetically insulated from each other by a receiver spacer 222.

[0031] exist Figure 2-1 In , the first transmitting coil 216-1 is active and generates a magnetic field to transfer power to the first receiving coil 220-1 that is close to the first transmitting coil 216-1. Figure 2-2, according to some embodiments, the accessory device 200 is positioned in a second charging position on the second surface 210 of the electronic device 202. The second transmitting coil 216-2 is active and generates a magnetic field to transfer power to the second receiving coil 220-2 proximate to the second transmitting coil 216-2.

[0032] In some embodiments, a wireless charging system includes a set of two transmitting coils and two receiving coils, the set being contained within a flexible printed circuit board (FPC) that is folded around other mechanical components to create a stack that positions the transmitting coils and receiving coils proximate to the front and back of the device in which they are respectively contained. The mechanical components used in the stack include adhesives and magnetic field insulation layers. In some embodiments, a wireless charging system includes a set of two transmitting coils and two receiving coils, wherein at least one of the coils is one or more discrete coiled wires (e.g., Litz wire). In some embodiments, the discrete wires allow for additional coil designs or geometries other than the flat coil design of the FPC.

[0033] Figure 3 A plan view of a transmitter 312 (e.g., an FPC transmitter) is illustrated in accordance with some embodiments. The transmitter 312 (e.g., the transmitter 212) includes a first transmitting coil 316-1 located in a first portion 324 of the FPC and a second transmitting coil 316-2 located in a second portion 326 of the FPC. The first portion 324 and the second portion 326 are connected by a flexible connector 328. Both the first transmitting coil 316-1 and the second transmitting coil 316-2 are in electrical communication with a terminal 330 through an electrical connection for each coil, allowing each coil to be individually activated through the terminal 330. The first transmitting coil 316-1 is connected to the terminal 330 through the flexible connector 328.

[0034] In some embodiments, the transmitter 312 includes an alignment hole adjacent to the coil 316. In some embodiments, the device (e.g., electronic device 102) includes an alignment post configured to align the transmitter 312 to the electronic device 102 via the alignment hole. In some embodiments, the electronic device 102 includes an alignment post as described below with reference to Figure 8 In some embodiments, the alignment posts and alignment holes are configured to align coil 316 with the magnetic alignment features so that an accessory coupled to the magnetic alignment features has its receiver coil in close proximity (e.g., aligned) with a corresponding transmitter coil. In some embodiments, the alignment holes are connected to the transmitter coil 316, rather than another portion of the transmitter 312 (such as spacer 318), to minimize alignment mismatch between the magnetic alignment features and the coil 316.

[0035] In some embodiments, a charging system (e.g., charging system 101) includes an accessory device (e.g., accessory device 100) and an electronic device (e.g., electronic device 102). The electronic device can be a laptop computer, a tablet computer, a hybrid computer, a smart phone, a smart TV, other electrical appliances, a motor vehicle (e.g., in a passenger compartment of a motor vehicle), or another electronic device. For example, the electronic device can be a laptop computer having a first portion and a second portion that can be moved by a hinge. The first portion can include a display, and the second portion has at least one user input device, such as a keyboard or a touch-sensitive surface, such as a pressure-sensitive or capacitive-sensitive surface.

[0036] The accessory device may be any accessory device powered by electricity. In some embodiments, the accessory device is a device for use with an electronic device, such as a Bluetooth-enabled accessory that communicates data with the electronic device. In a non-limiting example, the accessory device may be a user input device, such as a keyboard, mouse, touchpad, trackball, stylus, presentation remote control, pointer, game controller, or other device for interacting with an electronic device and / or providing input to the electronic device via a data connection. In a specific example, the electronic device is a laptop computer and the accessory device is a keyboard. In other examples, the accessory device is an audio and / or video output device that communicates data with the electronic device. In another specific example, the electronic device is a smart television and the accessory device is an audio output device, such as a Bluetooth-enabled speaker or headset.

[0037] In some embodiments, the accessory device is a device that operates independently of the electronic device. For example, the accessory device is a tablet computer, a hybrid computer, a smartphone, a smart watch, a head mounted display, another wearable device, a headset, an earphone, or other device that can operate independently of the electronic device. In a specific example, the electronic device is a hybrid computer and the accessory device is a smartphone.

[0038] In some embodiments, the accessory device can be charged from the electronic device in a first charging position and a second charging position. The first charging position is on a first surface of the electronic device and the second charging position is on an opposite second surface of the electronic device. The accessory device can receive power from the electronic device in the first charging position or the second charging position.

[0039] In some embodiments, the charging power (e.g., the induced current in the receiver) received by the accessory device is the same regardless of whether the accessory device is in the first charging position or the second charging position. In some embodiments, the charging power received by the accessory device varies regardless of whether the accessory device is in the first charging position or the second charging position. The charging power may vary depending on the distance between the transmitting coil and the receiving coil, the charging current applied to the transmitting coil, the size of the transmitting coil, the material of the transmitting coil, the size of the receiving coil, the material of the receiving coil, the in-plane alignment of the transmitting coil and the receiving coil, the angular orientation of the transmitting coil and the receiving coil, and other variables.

[0040] In some examples, the first charging position induces a larger induced current in the accessory device because the housing of the electronic device is thinner near the first surface of the electronic device than near the second surface of the electronic device, so that the distance between the powered transmitting coil and the receiving coil is smaller in the first charging position than in the second charging position. In other examples, the first charging position induces a larger induced current in the accessory device because the powered transmitting coil near the first surface is larger than the transmitting coil near the second surface, so that the magnetic field generated by the transmitting coil near the first charging position is larger than the magnetic field generated by the transmitting coil near the second charging position.

[0041] Figure 4 According to some embodiments Figure 3 316-2 and a second transmitting coil 316-2. The transmitter 312 includes a first transmitting coil 316-1 and a second transmitting coil 316-2 and a transmitter spacer 318 therebetween. The spacer 318 is sandwiched between a first portion 324 of the FPC and a second portion 326 of the FPC. In some embodiments, the transmitting coils 316-1, 316-2 of the transmitter 312 are spaced apart from one another to position each of the transmitting coils 316-1, 316-2 proximate to an opposing surface of an electronic device housing. Similarly, in some embodiments, the receiving coils of the receiver are spaced apart from one another to position each receiving coil proximate to an opposing surface of an accessory device housing.

[0042] Because the charging power provided to the receiver is related to the proximity of the transmitting coil, in some embodiments, only one of the transmitting coils 316-1, 316-2 is powered by the charging current at any given time. Powering only one transmitting coil 316-1, 316-2 can reduce power consumption and provide more efficient power transfer. The transmitter spacer 318 located between the first transmitting coil 316-1 and the second transmitting coil 316-2 magnetically isolates the first transmitting coil 316-1 and the second transmitting coil 316-2 from each other.

[0043] Figure 5-1 and Figure 5-2According to some embodiments Figure 3 and Figure 4 A side view of the transmitter 312 is shown. Figure 5-1 A first magnetic field 332-1 generated by the first transmitting coil 316-1 is shown. The first magnetic field 332-1 extends from the upper surface 334 of the transmitter 312. Although the first magnetic field 332-1 also extends in the opposite direction toward the spacer 318, the magnetic insulation and / or shielding material of the spacer 318 cancels out the portion of the first magnetic field 332-1 in the direction of the spacer 318. In this way, the first magnetic field 332-1 does not affect the second transmitting coil 316-2.

[0044] Figure 5-2 A second magnetic field 332-2 generated by the first transmitting coil 316-1 is shown. The second magnetic field 332-2 extends from the lower surface 336 of the transmitter 312. Although the second magnetic field 332-2 also extends in the opposite direction toward the spacer 318, the magnetic insulation and / or shielding material of the spacer 318 cancels out the portion of the second magnetic field 332-2 in the direction of the spacer 318. In this way, the second magnetic field 332-2 does not affect the first transmitting coil 316-1.

[0045] In some embodiments, the spacer 318 includes a magnetic shielding material that limits or prevents magnetic coupling of the first transmitting coil 316-1 and the second transmitting coil 316-2 when one of the first transmitting coil 316-1 and the second transmitting coil 316-2 is powered. In some embodiments, the spacer 318 includes a conductive material. In some embodiments, the spacer 318 includes a magnetic material. In some embodiments, the spacer 318 includes a ferromagnetic material. In one example, the spacer 318 includes ferrite. In another example, the spacer 318 includes ferrite and zinc to further prevent magnetic flux (extension, leakage) beyond the ferrite or magnetic material. Charge carrier particles in the conductive material can move in the presence of a magnetic field and thereby counteract the magnetic field.

[0046] In some embodiments, a spacer is located in the receiver to separate the first receiving coil and the second receiving coil from each other. The spacer may include a magnetic shielding material that limits or prevents magnetic coupling of the first receiving coil and the second receiving coil when one of the first receiving coil and the second receiving coil is exposed to a magnetic field from one side. In some embodiments, the spacer includes a conductive material. In some embodiments, the spacer includes a magnetic material. In some embodiments, the spacer includes a ferromagnetic material. In at least one embodiment, the spacer includes a ferrite. In at least one embodiment, the spacer includes zinc.

[0047] In some embodiments, the coils are printed on a single FPC in one or both of the transmitter and the receiver. For example, a first transmitter coil and a second transmitter coil are printed on a single FPC. In another example, a first receiver coil and a second receiver coil are printed on a single FPC. In some embodiments, the coils are supported by a flexible connector so that both coils and terminals are all printed on a single FPC that can be folded upon itself to create a set of "stacked" coils.

[0048] Although each transmitting coil 316-1, 316-2 generates a magnetic field that extends away from the transmitting coil in a direction perpendicular to the plane of the coil, the spacer 318 located between the two transmitting coils 316-1, 316-2 attenuates or stops the magnetic field 332-1, 332-2 in the direction of the spacer 318. For example, the magnetic field generated by the upper transmitting coil extends upward from the upper transmitting coil, and the spacer shields the lower transmitting coil (and other electronic devices or objects) from the associated downward portion of the magnetic field. In another example, the magnetic field generated by the lower transmitting coil extends downward from the upper transmitting coil, and the spacer shields the upper transmitting coil (and other electronic devices or objects) from the associated upward portion of the magnetic field.

[0049] In some embodiments, the first transmitting coil 316-1 and the second transmitting coil 316-2 are aligned with each other. In some embodiments, the first transmitting coil 316-1 and the second transmitting coil 316-2 are positioned by sharing a central axis 338. In some embodiments, the first transmitting coil 316-1 and the second transmitting coil 316-2 are parallel to each other. In other examples, the first transmitting coil 316-1 and the second transmitting coil 316-2 have the same area. In some embodiments, the first transmitting coil 316-1 and the second transmitting coil 316-2 have the same area, have the same shape, and share a central axis. In at least one embodiment, the first transmitting coil 316-1 and the second transmitting coil 316-2 have the same area, have the same shape, share a central axis, and are parallel so that the first transmitting coil 316-1 and the second transmitting coil 316-2 are symmetrical about a mirror plane passing through the spacer 318. For example, when one of the transmitting coils 316-1, 316-2 generates a magnetic field 332-1, 332-2, the spacer 318 shields the other transmitting coil 316-1, 316-2 from the magnetic field 332-1, 332-2 to prevent magnetic coupling of the transmitting coils 316-1, 316-2.

[0050] Figure 6320-2, and the first receiving coil 320-1 and the second receiving coil 320-2 are connected by the connector 328, and the first receiving coil 320-1 and the second receiving coil 320-2 are positioned opposite to each other on either side of the spacer 322. In some embodiments, the first receiving coil 320-1 and the second receiving coil 320-2 are aligned with each other. In some embodiments, the first receiving coil 320-1 and the second receiving coil 320-2 are positioned by sharing a central axis. In some embodiments, the first receiving coil 320-1 and the second receiving coil 320-2 are parallel to each other. In other examples, the first receiving coil 320-1 and the second receiving coil 320-2 have the same area. In some embodiments, the first receiving coil 320-1 and the second receiving coil 320-2 have the same area, have the same shape, and share a central axis. In some embodiments, the first receiving coil 320-1 and the second receiving coil 320-2 have the same area, have the same shape, share a central axis, and are parallel so that the first receiving coil and the second receiving coil are symmetrical about a mirror plane passing through the spacer 322. For example, when one receive coil is subjected to a magnetic field, the spacer 322 of the receiver 314 shields the other transmit coil from the magnetic field.

[0051] In some embodiments, the electronic device and / or accessory device has a housing having non-parallel housing surfaces. Because magnetic coupling of a transmit coil and a receive coil is generally most efficient when they are closest and parallel (due to the magnetic field extending in a direction perpendicular to the plane of the transmit coil), the transmit coil and / or receive coil can be positioned to be parallel to the housing surfaces, regardless of the orientation relative to the paired transmit coil and / or receive coil.

[0052] In some embodiments, the accessory device has a wedge-shaped housing such that an upper surface is oriented at an angle to a lower surface of the accessory device. In some embodiments, the accessory device has a curved surface. In some embodiments, the accessory device has a faceted surface. In such embodiments, the receiver coil of the receiver is positioned parallel to (or substantially parallel to) a surface of the accessory device housing proximate to the receiver coil. In some embodiments, the receiver coils are angled relative to each other (e.g., to account for the wedge shape of the accessory in which they are mounted). In some embodiments, the receiver coils are angled so as to be parallel to respective surfaces of the device in which they are mounted. Thus, as Figure 6 As shown, in some embodiments, the spacer 322 has a wedge shape so that a portion of the first receiving coil 320-1 is closer to a second portion of the second receiving coil 320-2 than a second portion of the receiving coil 320-1 is to a second portion of the second receiving coil 320-2.

[0053] like Figure 6As shown, according to some embodiments, the spacer 322 of the receiver 314 has non-parallel surfaces to complement the angle between the housing surfaces and the associated angle between the first receiving coil 320-1 and the second receiving coil 320-2. In some embodiments, the spacer 322 is a solid magnetic shielding material sheet having an upper surface and a lower surface oriented at an angle relative to each other. In some embodiments, the spacer 322 includes two or more pieces of magnetic shielding material and a wedge-shaped adhesive or other material located therebetween. In some embodiments, the spacer 322 includes two or more magnetic materials of uniform shape and a non-magnetic material therebetween. For example, using a magnetic shielding material of uniform thickness instead of machining an angle into the magnetic shielding material can reduce manufacturing costs or resources. In some embodiments, the spacer 322 includes two or more magnetic materials 340 (e.g., ferrite) and a wedge-shaped non-magnetic material 342 (e.g., zinc) therebetween.

[0054] When the transmitting coil 316 and the receiving coil 320 are aligned about the shared central axis 344 in parallel planes of the coils 316, 320 and the transmitting coil 316 and the receiving coil 320 are in close proximity, efficient power transfer occurs between the transmitting coil 316 and the receiving coil 320 via the magnetic field, such as in Figure 7 In some embodiments, the accessory device 300 aligns one of the transmitting coils 316 and one of the receiving coils 320 relative to the first charging position and / or the second charging position of the electronic device 302. In some embodiments, the transmitting coil 316 is proximate to the receiving coil 320, and the transmitting coil 316 and the receiving coil 320 are aligned when each of the transmitting coil 316 and the receiving coil 320 is located in a plane parallel to each other. In some embodiments, the transmitting coil 316 and the receiving coil 320 are aligned when they share a central axis 344. In one example, the transmitting coil 316 and the receiving coil 320 are aligned when they are located in planes parallel to each other and share a central axis 344.

[0055] The electronic device 302 provides a charging current through the transmitting coil 316 near the accessory device 300 to generate a magnetic field to couple the coils 316, 320. In some embodiments, the charging current is within a range having an upper limit, a lower limit, or both, including any of 100 milliwatts (mW), 200 milliwatts, 300 milliwatts, 400 milliwatts, 500 milliwatts, 600 milliwatts, 700 milliwatts, 1.0 Watt, 2.0 Watts, 3.0 Watts, 5.0 Watts, 7.5 Watts, 10.0 Watts, 12.5 Watts, 15.0 Watts, or any value therebetween. In some embodiments, the charging current is greater than 100 mW. In some embodiments, the charging current is less than 15.0 W. In some embodiments, the charging current is between 100 mW and 15.0 W. In some embodiments, the charging current is between 500 mW and 10.0 W. In one example, the charging current target is 1.0 W.

[0056] The charging current generates a magnetic field when the charging current flows through the transmitting coil 316. The magnetic field induces an induced current in the receiving coil 320 located within the magnetic field. In some embodiments, the induced current is within a range having an upper limit value, a lower limit value, or an upper limit and a lower limit value, and these values ​​include any of 50 milliwatts (mW), 100 milliwatts, 200 milliwatts, 300 milliwatts, 400 milliwatts, 500 milliwatts, 600 milliwatts, 700 milliwatts, 700 milliwatts, 1.0 Watt, 2.0 Watts, 3.0 Watts, 5.0 Watts, 7.5 Watts, or any value therebetween. In some embodiments, the induced current is greater than 50 mW. In some embodiments, the induced current is less than 7.5 W. In some embodiments, the induced current is between 50 mW and 7.5 W. In some embodiments, the induced current is between 100 mW and 5.0 W. In one example, the induced current target is 200 mW.

[0057] The proportion of the charging current delivered to the induced current is the inductive efficiency of the system. In some embodiments, the inductive efficiency may be within a range having an upper limit, a lower limit, or both, including any of 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, or any value therebetween. In some embodiments, the inductive efficiency when the transmitting coil is aligned with the receiving coil is greater than 5%. In some embodiments, the inductive efficiency is less than 50%. In some embodiments, the inductive efficiency is between 5% and 50%. In some embodiments, the inductive efficiency is between 10% and 35%. In one example, the inductive efficiency is 25%.

[0058] In some embodiments, the distance 346 between the transmitting coil 316 and the corresponding receiving coil 320 (e.g., through the housing material, keyboard, display glass, etc.) is within a range having an upper value, a lower value, or both, including any of 1 millimeter (mm), 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, 4.0 mm, 5.0 mm, 6.0 mm, 8.0 mm, 10.0 mm, or any value therebetween. In some embodiments, the distance 346 between the transmitting coil 316 and the receiving coil 320 is greater than 1.0 mm. In some embodiments, the distance 346 is less than 10.0 mm. In some embodiments, the distance 346 is between 1.0 mm and 10.0 mm. In some embodiments, the distance 346 is between 1.5 mm and 3.5 mm. In one example, the distance 346 is 2.0 mm.

[0059] Although the transmitting coil and receiving coil have been described herein as powering the receiving coil from the transmitting coil, it should be understood that the charging current may also be applied to the receiving coil to generate a magnetic field. For example, when the first transmitting coil receives the charging current and generates a magnetic field, the magnetic field induces an induced current in the first receiving coil near the first transmitting coil, and the induced current (or another current) may be applied to the second coil of the receiver to generate a second magnetic field away from the transmitter. The second magnetic field may also be used to power and / or charge another device. In some embodiments, the transmitting coil may be located in a magnetic field to receive power from an external source.

[0060] Now refer to Figure 8 Because the inductive efficiency of the charging system is based on the alignment of the transmitting coil with the receiving coil, in some embodiments, the charging system includes one or more alignment features 448 to help the user align the receiver 414 and the transmitter 412. In some embodiments, the alignment features 448 include one or more mechanical alignment features 448-1, such as interlocking protrusions and recesses, pins, holes, slots, posts, or other complementary static features.

[0061] In some embodiments, alignment features 448 include mechanical fasteners that secure the accessory device in a charging position relative to the electronic device, such as clamps, clips, bolts, or other selective fasteners that can selectively retain and release the accessory device.

[0062] like Figure 8 As shown, in some embodiments, alignment feature 448 includes a magnetic alignment feature 448-2, such as a permanent magnet and / or an electromagnet located in one or both of the accessory device and the electronic device. The magnetic alignment feature can apply both an attraction perpendicular to the surface to hold the accessory device against the electronic device and an attraction transverse to the surface to align the accessory device with the surface of the electronic device in a plane. Figure 8It is further shown how different alignment features 448 can work together to provide both a mechanical interlock and a magnetic attraction to assist in the alignment of the transmitter 412 and the receiver 414 .

[0063] Providing charging current to one or both transmit coils at all times consumes a lot of power and is inefficient, and can cause thermal issues in the device. Fig. 9 is a flow chart illustrating a method 550 for charging a device according to the present disclosure. In some embodiments, the method 550 for wirelessly charging an accessory device includes detecting the presence of a receiving coil proximate to a transmitting coil and then providing a charging current to the transmitting coil to induce a current in the receiving coil. In some embodiments, detecting the presence of the receiving coil includes measuring the current applied to the transmitting coil. The current will be constant when applied to the transmitting coil unless a conductive object is located in the magnetic field generated by the transmitting coil. When a conductive object is present in the magnetic field, the conductive object will modify the magnetic field, thereby affecting the current in the transmitting coil.

[0064] The method 550 includes providing (at 552) a first simulated pinning current to a first transmitting coil proximate an upper surface of the electronic device to generate a first magnetic field through the first transmitting coil, wherein at least a portion of the first magnetic field is above the upper surface. The method 550 then includes stopping the first simulated pinning current and providing (at 554) a second simulated pinning current to a second transmitting coil proximate a lower surface of the electronic device opposite the upper surface to generate a second magnetic field through the second transmitting coil, wherein at least a portion of the second magnetic field is below the lower surface.

[0065] The simulated check current applied to the transmit coil need not be the full charging current, since the simulated check only needs to detect the presence of a conductive material proximate to the transmit coil, and does not need to deliver power to the conductive material. In some embodiments, the simulated check current applied to the transmit coil (e.g., to generate a simulated check and detect the conductive material proximate to the transmit coil) is less than the charging current. In some embodiments, the simulated check current is within a range having an upper limit, a lower limit, or both, including any of 50 milliwatts (mW), 100 mW, 200 mW, 300 mW, 400 mW, 500 mW, 600 mW, 700 mW, 700 mW, 1.0 Watt, 2.0 Watt, 3.0 Watt, 5.0 Watt, 7.5 Watt, or any value therebetween. In some embodiments, the simulated check current is greater than 50 mW. In some embodiments, the simulated check current is less than 7.5 W. In some embodiments, the simulated check current is between 50 mW and 7.5 W. In some embodiments, the analog ping current is between 100 mW and 5.0 W. In one example, the analog ping current target is 125 mW.

[0066] In some embodiments, the transmitter alternates between emitting a simulated verification magnetic field from a first transmitting coil and emitting a simulated verification magnetic field from a second transmitting coil. The duration of each simulated verification is within a range having an upper limit, a lower limit, or both, including any of 1 millisecond (1 ms), 5 ms, 10 ms, 15 ms, 20 ms, 25 ms, 50 ms, 100 ms, 250 ms, 1 second, or any value therebetween. In some embodiments, the duration of each simulated verification is greater than 1 ms. In some embodiments, the duration of each simulated verification is less than 1 s. In some embodiments, the duration of each simulated verification is between 1 ms and 1 s. In some embodiments, the duration of each simulated verification is between 5 ms and 250 ms. In some embodiments, the duration of each simulated verification is 10 ms.

[0067] The simulated ping and the detection of changes measured in the simulated ping current (at 556) simulate the presence of a conductive material in the ping magnetic field. In some embodiments, subsequent communications (e.g., digital communications or a series of magnetic field pulses and / or amplitudes) may be communicated to the receiver to confirm that the conductive material is the receiving coil and not just a metal object, such as a metal tabletop. Subsequent communications may allow data communication with an accessory device through the receiver. For example, a near field communication "wake-up" standard may provide data communication between devices using a magnetic field.

[0068] In some embodiments, the accessory device can respond to the digital interrogation with a confirmation signal using a radio frequency (RF) wireless data signal to communicate with the RF transceiver and communication device of the electronic device. In some embodiments, the accessory device can respond to the digital interrogation with a confirmation signal using a current applied to a receiving coil (as described above) to generate a magnetic field through the receiving coil. The magnetic field can be detected by the electronic device to confirm the presence of the receiving coil.

[0069] After detecting the presence of the receiving coil in proximity to the transmitting coil, the method includes providing (at 558) a charging current to the transmitting coil to generate a charging magnetic field. In some embodiments, the charging current is applied to the first transmitting coil when an induced current is detected in response to the first magnetic field and is applied to the second transmitting coil when an induced current is detected in response to the second magnetic field.

[0070] Industrial Applicability

[0071] The present disclosure generally relates to providing power to an electronic accessory to power the electronic accessory and / or wirelessly charge a battery of the electronic accessory. In some embodiments, the electronic accessory is powered by an electronic device such as a laptop computer, a tablet computer, a hybrid computer, a smartphone, a smart television, other appliances, a motor vehicle such as in a passenger compartment of a motor vehicle, or another electronic device. In some embodiments, wirelessly powering the accessory device includes positioning the accessory device in one of a plurality of positions relative to the electronic device.

[0072] In some embodiments, a wireless charging system includes a set of two transmitting coils and two receiving coils. The transmitting coils and receiving coils are contained within a flexible printed circuit board (FPC) that is folded around other mechanical components to create a stack that positions the transmitting coils and receiving coils close to the front and back of the device they are respectively contained within. The mechanical components used in the stack include adhesives and magnetic field insulation layers.

[0073] In some embodiments, the charging system includes an accessory device and an electronic device. The electronic device can be a laptop computer, a tablet computer, a hybrid computer, a smart phone, a smart television, other appliances, a motor vehicle (e.g., in a passenger compartment of a motor vehicle), or another electronic device. For example, the electronic device can be a laptop computer having a first portion and a second portion that can be moved by a hinge. The first portion can include a display, and the second portion has at least one user input device, such as a keyboard or a touch-sensitive surface, such as a pressure-sensitive or capacitive-sensitive surface.

[0074] The accessory device may be any accessory device powered by electricity. In some embodiments, the accessory device is a device for use with an electronic device, such as a Bluetooth-enabled accessory that communicates data with the electronic device. In a non-limiting example, the accessory device may be a user input device, such as a keyboard, mouse, touchpad, trackball, stylus, presentation remote control, pointer, game controller, or other device for interacting with an electronic device and / or providing input to the electronic device via a data connection. In a specific example, the electronic device is a laptop computer and the accessory device is a keyboard. In other examples, the accessory device is an audio and / or video output device that communicates data with the electronic device. In another specific example, the electronic device is a smart television and the accessory device is an audio output device, such as a Bluetooth-enabled speaker or headset.

[0075] In some embodiments, the accessory device is a device that operates independently of the electronic device. For example, the accessory device is a tablet computer, a hybrid computer, a smartphone, a smart watch, a head mounted display, another wearable device, a headset, an earphone, or other device that can operate independently of the electronic device. In a specific example, the electronic device is a hybrid computer and the accessory device is a smartphone.

[0076] In some embodiments, the accessory device can be charged from the electronic device in a first charging position and a second charging position. The first charging position is on a first surface of the electronic device and the second charging position is on an opposite second surface of the electronic device. The accessory device can receive power from the electronic device in the first charging position or the second charging position.

[0077] In some embodiments, the charging power (e.g., the induced current in the receiver) received by the accessory device is the same regardless of whether the accessory device is in the first charging position or the second charging position. In some embodiments, the charging power received by the accessory device varies regardless of whether the accessory device is in the first charging position or the second charging position. The charging power may vary depending on the distance between the transmitting coil and the receiving coil, the charging current applied to the transmitting coil, the size of the transmitting coil, the material of the transmitting coil, the size of the receiving coil, the material of the receiving coil, the in-plane alignment of the transmitting coil and the receiving coil, the angular orientation of the transmitting coil and the receiving coil, and other variables.

[0078] In some examples, the first charging position induces a larger induced current in the accessory device because the housing of the electronic device is thinner near the first surface of the electronic device than near the second surface of the electronic device, so that the distance between the powered transmitting coil and the receiving coil is smaller in the first charging position than in the second charging position. In other examples, the first charging position induces a larger induced current in the accessory device because the powered transmitting coil near the first surface is larger than the transmitting coil near the second surface, so that the magnetic field generated by the transmitting coil near the first charging position is larger than the magnetic field generated by the transmitting coil near the second charging position.

[0079] In some embodiments, the transmit coils of the transmitter are spaced apart from each other to position each transmit coil proximate to an opposing surface of the electronic device housing. Similarly, in some embodiments, the receive coils of the receiver are spaced apart from each other to position each receive coil proximate to an opposing surface of the accessory device housing.

[0080] Because the charging power provided to the receiver is exponentially related to the proximity of the transmitting coil, in some embodiments, only one transmitting coil is powered by the charging current at a time. Powering only one transmitting coil can reduce power consumption and provide more efficient power transfer. A spacer located between the first transmitting coil and the second transmitting coil can magnetically isolate the first transmitting coil and the second transmitting coil from each other.

[0081] In some embodiments, the spacer includes a magnetic shielding material that limits or prevents magnetic coupling of the first transmitting coil and the second transmitting coil when one of the first transmitting coil and the second transmitting coil is powered. In some examples, the spacer includes a conductive material. In other examples, the spacer includes a magnetic material. In other examples, the spacer includes a ferromagnetic material. In at least one embodiment, the spacer includes a ferrite. In at least another embodiment, the spacer includes zinc to further prevent magnetic flux from overflowing the ferrite or magnetic material. Charge carrier particles in the conductive material can move in the presence of a magnetic field and counteract the magnetic field.

[0082] In some embodiments, a spacer is located in the receiver to separate the first receiving coil and the second receiving coil from each other. The spacer may include a magnetic shielding material that limits or prevents magnetic coupling of the first receiving coil and the second receiving coil when one of the first receiving coil and the second receiving coil is exposed to a magnetic field from one side. In some examples, the spacer includes a conductive material. In other examples, the spacer includes a magnetic material. In other examples, the spacer includes a ferromagnetic material. In at least one embodiment, the spacer includes ferrite. In at least another embodiment, the spacer includes zinc.

[0083] In one or both of the transmitter and the receiver, the coils are printed on a single FPC. In some examples, the first transmit coil and the second transmit coil are printed on a single FPC. In other examples, the first receiver coil and the second receiver coil are printed on a single FPC. The coils may be supported by a flexible connector so that both coils and terminals are all printed on a single FPC that can be folded upon itself to create a set of "stacked" coils.

[0084] Although each transmitting coil generates a magnetic field that extends away from the transmitting coil in a direction perpendicular to the plane of the coil, the spacer located between the two transmitting coils will attenuate or stop the magnetic field in the direction of the spacer. For example, the magnetic field generated by the upper transmitting coil will extend upward from the upper transmitting coil, and the spacer will shield the lower transmitting coil (and other electronic devices or objects) from the associated downward portion of the magnetic field. In another example, the magnetic field generated by the lower transmitting coil will extend downward from the upper transmitting coil, and the spacer will shield the upper transmitting coil (and other electronic devices or objects) from the associated upward portion of the magnetic field.

[0085] In some embodiments, the first transmitting coil and the second transmitting coil are aligned with each other. In some examples, the first transmitting coil and the second transmitting coil are positioned by sharing a central axis. In other examples, the first transmitting coil and the second transmitting coil are parallel to each other. In other examples, the first transmitting coil and the second transmitting coil have the same area. In other examples, the first transmitting coil and the second transmitting coil have the same area, have the same shape, and share a central axis. In at least one example, the first transmitting coil and the second transmitting coil have the same area, have the same shape, share a central axis, and are parallel so that the first transmitting coil and the second transmitting coil are symmetrical about a mirror plane passing through the spacer. For example, when one transmitting coil generates a magnetic field, the spacer shields the other transmitting coil from the magnetic field.

[0086] In some embodiments, the receiver includes a first receiving coil and a second receiving coil positioned on either side of a spacer relative to each other. In some embodiments, the first receiving coil and the second receiving coil are aligned with each other. In some examples, the first receiving coil and the second receiving coil are positioned by sharing a central axis. In other examples, the first receiving coil and the second receiving coil are parallel to each other. In other examples, the first receiving coil and the second receiving coil have the same area. In other examples, the first receiving coil and the second receiving coil have the same area, have the same shape, and share a central axis. In at least one example, the first receiving coil and the second receiving coil have the same area, have the same shape, share a central axis, and are parallel so that the first receiving coil and the second receiving coil are symmetrical about a mirror plane passing through the spacer. For example, when one receiving coil is subjected to a magnetic field, the spacer of the receiver shields the other transmitting coil from the magnetic field.

[0087] In some embodiments, the electronic device and / or accessory device has a housing having non-parallel housing surfaces. Because magnetic coupling of a transmit coil and a receive coil is generally most efficient when they are closest and parallel (due to the magnetic field extending in a direction perpendicular to the plane of the transmit coil), the transmit coil and / or receive coil can be positioned to be parallel to the housing surfaces, regardless of the orientation relative to the paired transmit coil and / or receive coil.

[0088] In some embodiments, the accessory device has a wedge-shaped housing such that the upper surface is oriented at an angle to the lower surface of the accessory device. In some embodiments, the accessory device has a curved surface. In some embodiments, the accessory device has a faceted surface. In such embodiments, the receiver coil of the receiver is positioned parallel to (or substantially parallel to) a surface of the accessory device housing proximate to the receiver coil.

[0089] The spacer of the receiver has non-parallel surfaces to complement the angle between the housing surfaces and the associated angle between the receiving coils. In some embodiments, the spacer is a solid sheet of magnetic shielding material having an upper surface and a lower surface oriented at an angle relative to each other. In some embodiments, the spacer includes two or more sheets of magnetic shielding material and a wedge of adhesive or other gap filling material located therebetween. For example, using a uniform thickness of magnetic shielding material rather than machining angles into the magnetic shielding material can reduce manufacturing costs or resources.

[0090] Efficient power transfer occurs between the transmitting coil and the receiving coil via a magnetic field when the transmitting coil and the receiving coil are aligned in parallel planes of the coils about a shared central axis and the transmitting coil and the receiving coil are as close as possible. In some embodiments, the accessory device aligns one of the transmitting coils and one of the receiving coils relative to a first charging position and / or a second charging position of the electronic device. In some embodiments, the transmitting coil is close to the first receiving coil, and the first transmitting coil and the first receiving coil are aligned when each of the first transmitting coil and the first receiving coil is located in a plane parallel to each other. In other examples, the first transmitting coil and the first receiving coil are aligned when they share a central axis. In at least one example, the first transmitting coil and the first receiving coil are aligned when they are located in planes parallel to each other and share a central axis.

[0091] The electronic device provides a charging current through a transmitting coil close to the accessory device to generate a magnetic field to couple the coil. In some embodiments, the charging current is within a range having an upper limit, a lower limit, or both, including any of 100 milliwatts (mW), 200 milliwatts, 300 milliwatts, 400 milliwatts, 500 milliwatts, 600 milliwatts, 700 milliwatts, 1.0 Watt, 2.0 Watts, 3.0 Watts, 5.0 Watts, 7.5 Watts, 10.0 Watts, 12.5 Watts, 15.0 Watts, or any value therebetween. In some examples, the charging current is greater than 100 mW. In some examples, the charging current is less than 15.0 W. In some examples, the charging current is between 100 mW and 15.0 W. In some examples, the charging current is between 500 mW and 10.0 W. In at least one example, the charging current target is approximately 1.0 W.

[0092] The charging current generates a magnetic field when the charging current flows through the transmitting coil. The magnetic field induces an induced current in the receiving coil located within the magnetic field. In some embodiments, the induced current is within a range having an upper limit value, a lower limit value, or an upper limit and a lower limit value, and these values ​​include any of 50 milliwatts (mW), 100 milliwatts, 200 milliwatts, 300 milliwatts, 400 milliwatts, 500 milliwatts, 600 milliwatts, 700 milliwatts, 700 milliwatts, 1.0 watts, 2.0 watts, 3.0 watts, 5.0 watts, 7.5 watts, or any value therebetween. In some examples, the induced current is greater than 50 mW. In some examples, the induced current is less than 7.5 W. In some examples, the induced current is between 50 mW and 7.5 W. In some examples, the induced current is between 100 mW and 5.0 W. In at least one example, the induced current target is 200 mW.

[0093] The proportion of the charging current delivered to the induced current is the inductive efficiency of the system. In some embodiments, the inductive efficiency may be within a range having an upper limit, a lower limit, or both, including any of 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, or any value therebetween. In some examples, the inductive efficiency when the transmitting coil is aligned with the receiving coil is greater than 5%. In some examples, the inductive efficiency is less than 50%. In some examples, the inductive efficiency is between 5% and 50%. In some examples, the inductive efficiency is between 10% and 35%. In at least one example, the inductive efficiency is approximately 25%.

[0094] In some embodiments, the distance between the first transmitting coil and the first receiving coil (e.g., through housing material, keyboard, display glass, etc.) is within a range having an upper value, a lower value, or both, including any of 1 millimeter (mm), 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, 4.0 mm, 5.0 mm, 6.0 mm, 8.0 mm, 10.0 mm, or any value therebetween. In some embodiments, the distance between the first transmitting coil and the second transmitting coil is greater than 1.0 mm. In some examples, the distance is less than 10.0 mm. In some examples, the distance is between 1.0 mm and 10.0 mm. In some examples, the distance 346 is between 1.5 mm and 3.5 mm. In at least one example, the distance is approximately 2.0 mm.

[0095] Although the transmitting coil and receiving coil have been described herein as powering the receiving coil from the transmitting coil, it should be understood that the charging current can also be applied to the receiving coil and generate a magnetic field. For example, when the first transmitting coil receives the charging current and generates a magnetic field, the magnetic field induces an induced current in the first receiving coil near the first transmitting coil, and the induced current (or another current) can be applied to the second coil of the receiver to generate a second magnetic field away from the transmitter. The second magnetic field can also be used to power and / or charge another device. In some examples, the transmitting coil can be located in the magnetic field to receive power from an external source.

[0096] Because the inductive efficiency of the charging system is based on the alignment of the transmitting coil with the receiving coil, in some embodiments, the charging system includes one or more alignment features to help the user align the receiver and the transmitter. In some embodiments, the alignment feature is a mechanical alignment feature, such as interlocking protrusions and recesses, pins, holes, slots, posts, or other complementary static features. In some embodiments, the alignment feature is a mechanical fastener that fixes the accessory device in a charging position relative to the electronic device, such as a pliers, a clamp, a bolt, or other selective fastener that can selectively hold and release the accessory device. In some embodiments, the alignment feature includes a magnetic alignment feature, such as a permanent magnet and / or an electromagnet located in one or both of the accessory device and the electronic device. The magnetic alignment feature can apply a suction force perpendicular to the surface to hold the accessory device against the electronic device, and can apply a suction force transverse to the surface to align the accessory device with the surface of the electronic device in a plane.

[0097] Providing charging current to one or both transmitting coils at all times consumes a lot of power and is inefficient. In some embodiments, a method of wirelessly charging an accessory device includes detecting the presence of a receiving coil proximate to a transmitting coil and then providing charging current to the transmitting coil to induce a current in the receiving coil. In some examples, detecting the presence of the receiving coil includes measuring the current applied to the transmitting coil. The current will be constant when applied to the transmitting coil unless a conductive object is located in a magnetic field generated by the transmitting coil. When a conductive object is present in the magnetic field, the conductive object will modify the magnetic field, thereby affecting the current in the transmitting coil.

[0098] The simulated check current applied to the transmit coil need not be the full charging current, since the simulated check only needs to detect the presence of a conductive material proximate to the transmit coil, and does not need to deliver power to the conductive material. In some embodiments, the simulated check current applied to the transmit coil (e.g., to generate a simulated check and detect the conductive material proximate to the transmit coil) is less than the charging current. In some embodiments, the simulated check current is within a range having an upper limit, a lower limit, or both, including any of 50 milliwatts (mW), 100 mW, 200 mW, 300 mW, 400 mW, 500 mW, 600 mW, 700 mW, 700 mW, 1.0 Watt, 2.0 Watt, 3.0 Watt, 5.0 Watt, 7.5 Watt, or any value therebetween. In some embodiments, the simulated check current is greater than 50 mW. In some embodiments, the simulated check current is less than 7.5 W. In some embodiments, the simulated check current is between 50 mW and 7.5 W. In some embodiments, the analog ping current is between 100 mW and 5.0 W. In one example, the analog ping current target is 125 mW.

[0099] In some embodiments, the transmitter alternates between emitting a simulated verification magnetic field from a first transmitting coil and emitting a simulated verification magnetic field from a second transmitting coil. The duration of each simulated verification is within a range having an upper limit, a lower limit, or both, including any of 1 millisecond (1 ms), 5 ms, 10 ms, 15 ms, 20 ms, 25 ms, 50 ms, 100 ms, 250 ms, 1 second, or any value therebetween. In some embodiments, the duration of each simulated verification is greater than 1 ms. In some embodiments, the duration of each simulated verification is less than 1 s. In some embodiments, the duration of each simulated verification is between 1 ms and 1 s. In some embodiments, the duration of each simulated verification is between 5 ms and 250 ms. In some embodiments, the duration of each simulated verification is 10 ms.

[0100] The analog ping and the measured changes in the analog ping current detect the presence of a conductive material in the analog ping magnetic field. A subsequent digital ping or series of magnetic field pulses and / or amplitudes can be communicated to the receiver to confirm that the conductive material is the receiving coil and not just a metal object, such as a metal tabletop. The digital ping can allow data communication with an accessory device through the receiver. For example, the Near Field Communication "wake-up" standard can provide inter-device communication using a magnetic field.

[0101] In some embodiments, the accessory device can respond to the digital interrogation with a confirmation signal using a radio frequency (RF) wireless data signal to communicate with the RF transceiver and communication device of the electronic device. In some embodiments, the accessory device can respond to the digital interrogation with a confirmation signal using a current applied to a receiving coil (as described above) to generate a magnetic field through the receiving coil. The magnetic field can be detected by the electronic device to confirm the presence of the receiving coil.

[0102] After detecting the presence of a receiving coil proximate to the transmitting coil, the method includes providing a charging current to the transmitting coil to generate a charging magnetic field. In some embodiments, the charging current is applied to the first transmitting coil when an induced current is detected in response to the first magnetic field and is applied to the second transmitting coil when an induced current is detected in response to the second magnetic field.

[0103] In some embodiments, a charging system according to the present disclosure may allow an accessory device to be charged via any of a first surface or an opposing second surface of an electronic device through magnetic induction between one of a plurality of transmitting coils and one of a plurality of receiving coils, without magnetically coupling the transmitting coil to itself or magnetically coupling the receiving coil to itself. A charging system with stacked transmitting coils and / or receiving coils thus provides a more flexible and efficient power transfer system in a small footprint within the electronic device and the accessory device.

[0104] The present disclosure relates to systems and methods for wirelessly charging an accessory device from an electronic device using a magnetic field, according to examples provided in at least the following subsections:

[0105] 1. A device for inductively charging an electronic accessory, the device comprising:

[0106] Part I (324; Figure 4 ), comprising a first transmitting coil (316-1; Figure 4 ), the first transmitting coil is configured to generate a first magnetic field (332-1; Figure 5-1 );

[0107] Part II (326; Figure 4 ), including a second transmitting coil (316-2; Figure 4 ), the second transmitting coil is configured to generate a second magnetic field (332-2; Figure 5-2 );as well as

[0108] a spacer (318) located between the first transmitting coil and the second transmitting coil and between the first plane and the second plane; Figure 4 ), the spacer material magnetically insulates the second transmitting coil from the first magnetic field.

[0109] 2. The apparatus of subsection 1, wherein the first transmitting coil and the second transmitting coil are arranged along a central axis (338; Figure 5-2 )alignment.

[0110] 3. The device as described in subsection 2, wherein the first transmitting coil (316-1; Figure 3 ) has a first area and the second transmitting coil (316-2; Figure 3 ) has a second area, and the first area and the second area are the same.

[0111] 4. The device as described in any of subsections 1-3, wherein the spacer (318; Figure 4 ) includes ferromagnetic materials.

[0112] 5. The device as described in any of subsections 1-4, wherein the spacer (318; Figure 4 ) includes non-magnetic materials.

[0113] 6. The apparatus of any of subsections 1-5, wherein the first portion (324; Figure 3 ) and Part II (326; Figure 3 ) by a flexible connector (328; Figure 3 )connect.

[0114] 7. The apparatus as described in subsection 6, further comprising a terminal (330; Figure 3 ), wherein the terminal electrically communicates with the first transmitting coil through the flexible connector.

[0115] 8. The apparatus of any of subsections 1-7, wherein the first transmitting coil (316-1; Figure 3 ) and a second transmitting coil (316-2; Figure 3 ) are each part of a flexible printed circuit.

[0116] 9. A system for providing power from an electronic device to an accessory device, the system comprising:

[0117] Transmitter(312; Figure 7 ),include:

[0118] comprising a first transmitting coil (316-1; Figure 4 ),

[0119] comprising a second transmitting coil (316-2; Figure 3 ), and

[0120] Located at the first transmitting coil (316-1; Figure 4 ) and the second transmitting coil (316-2; Figure 4 ) between the emitter spacers (318; Figure 4 ), the spacer material magnetically insulating the second transmitting coil from the first magnetic field; and

[0121] Receiver(314; Figure 7 ),include:

[0122] a first portion, the first portion comprising a first receiving coil (320-1; Figure 6 ),

[0123] a second portion comprising a second receiving coil (320-2; Figure 6 ),as well as

[0124] a receiver spacer (322; Figure 6 ), the spacer material magnetically insulates the first receiving coil from the second receiving coil.

[0125] 10. The system of subsection 9, wherein the receiver spacer (322; Figure 6 ) is tapered to orient the first receive coil at a non-zero angle relative to the second receive coil.

[0126] 11. A system as described in subsection 9 or 10, wherein the receiver spacer (322; Figure 6 ) includes ferromagnetic materials.

[0127] 12. A system as described in any of subsections 9-11, wherein the receiver spacer (322; Figure 6 ) includes non-magnetic material (342; Figure 6 ).

[0128] 13. A system as described in any of subsections 9-12, wherein when one of the first transmitting coil and the second transmitting coil is aligned with one of the first receiving coil and the second receiving coil, a charging current applied to the transmitter induces an induced current in the receiver that is at least 15% of the charging current.

[0129] 14. A method for providing power from an electronic device to an accessory device, the method comprising:

[0130] At the electronic device:

[0131] providing (552) to a first transmitting coil proximate to a first surface of the electronic device; Fig. 9) a first interrogation current to generate a first magnetic field through the first transmitting coil, wherein a portion of the first magnetic field extends beyond the first surface;

[0132] After terminating the first interrogation current to the first transmitting coil, providing (554; Fig. 9 ) a second interrogation current to generate a second magnetic field through the second transmitting coil, wherein a portion of the second magnetic field extends beyond the second surface;

[0133] detecting (556) in response to one of the first magnetic field and the second magnetic field; Fig. 9 ) an induced current in a receiving coil of the accessory device; and

[0134] selectively providing (558;) to the first transmitting coil when the induced current is detected in response to the first magnetic field; Fig. 9 ) charging current and providing (558) to the second transmitting coil when the induced current is detected in response to the second magnetic field; Fig. 9 )Charging current.

[0135] 15. The method of subsection 14, wherein detecting the induced current includes detecting a change in a transmission current of one of the first magnetic coil and the second magnetic coil when the first magnetic field or the second magnetic field is applied to the receiving coil.

[0136] 16. The method of subsection 14 or 15, further comprising:

[0137] providing a communication signal to the one of the first magnetic coil and the second magnetic coil to generate a corresponding magnetic field after detecting the induced current; and

[0138] An acknowledgement signal is received from the accessory device in response to the corresponding magnetic field.

[0139] 17. The method of any of subsections 14-16, wherein detecting the induced current comprises receiving a wireless data signal from the accessory device after the accessory device measures the induced current in the receiving coil.

[0140] 18. The method of any of subsections 14-17, wherein providing the charging current comprises providing a charging current ranging from 1 Watt (W) to 15 W.

[0141] 19. The method of any of subsections 14-18, wherein the first verification current and the second verification current are each less than the charging current.

[0142] 20. The method of any of subsections 14-19, further comprising using an alignment feature of the electronic device to align the first transmitting coil or the second transmitting coil with the receiving coil.

[0143] The articles "one", "an" and "the" are intended to indicate that there are one or more of the elements in the preceding description. The terms "including", "comprising", and "having" are intended to be inclusive and indicate that there may be additional elements in addition to the listed elements. Additionally, it will be understood that reference to "one embodiment" or "an embodiment" of the present disclosure is not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the features. For example, any element described with respect to the embodiments herein may be combined with any element of any other embodiment described herein. The numerals, percentages, ratios or other values ​​set forth herein are intended to include the value, as well as other values ​​of the values ​​set forth "about" or "approximately", as will be appreciated by those of ordinary skill in the art as encompassed by the embodiments of the present disclosure. Therefore, the values ​​set forth should be interpreted broadly enough to cover values ​​of the values ​​set forth that are at least close enough to perform the desired function or achieve the desired result. The values ​​set forth include at least the changes expected in suitable processing or production processes, and may include values ​​within 5%, within 1%, within 0.1%, or within 0.01% of the values ​​set forth.

[0144] In view of the present disclosure, those of ordinary skill in the art will recognize that equivalent constructions do not depart from the spirit and scope of the present disclosure, and that various changes, substitutions, and modifications may be made to the embodiments disclosed herein without departing from the spirit and scope of the present disclosure. Equivalent constructions including functional "means plus function" clauses are intended to cover structures described herein as performing the functions, including both structural equivalents that operate in the same manner and equivalent structures that provide the same functions. It is the express intention of the applicant not to invoke means plus function or other functional claims in any claim unless the term "means for..." appears with the associated function. Each addition, deletion, and modification to the embodiments within the meaning and scope of the claims will be accepted by the claims.

[0145] It should be understood that any direction or reference frame in the foregoing description is only a relative direction or movement. For example, any reference to "front" and "back" or "top" and "bottom" or "left" and "right" merely describes the relative position or movement of the relevant elements.

[0146] The present disclosure may be embodied in other specific forms without departing from its spirit or characteristics. The described embodiments are considered to be illustrative rather than restrictive. Thus, the scope of the present invention is indicated by the appended claims rather than the foregoing description. Changes within the meaning and scope of the equivalent schemes of the claims should be covered by the scope of the claims.

Claims

1. A device for inductively charging an electronic accessory, the device comprising: a first portion comprising a first transmitting coil in a first plane, the first transmitting coil being configured to generate a first magnetic field; a second portion including a second transmitting coil in a second plane, the second transmitting coil being configured to generate a second magnetic field; as well as a spacer between the first transmitting coil and the second transmitting coil and between the first plane and the second plane, the spacer material magnetically insulating the second transmitting coil from the first magnetic field; The first part and the second part are connected by a flexible connector.

2. The apparatus of claim 1, wherein the first transmitting coil and the second transmitting coil are aligned along a central axis.

3. The apparatus of claim 2, wherein the first transmitting coil has a first area and the second transmitting coil has a second area, the first area and the second area being the same. The apparatus of claim 1 , wherein the spacer comprises a ferromagnetic material.

5. The apparatus of claim 1, wherein the spacer comprises a non-magnetic material.

6. The apparatus of claim 1, further comprising a terminal in electrical communication with the first transmitting coil and the second transmitting coil, wherein the terminal is in electrical communication with the first transmitting coil through the flexible connector.

7. The apparatus of claim 1, wherein the first transmit coil and the second transmit coil are each part of a flexible printed circuit.

8. A system for providing power from an electronic device to an accessory device, the system comprising: Transmitter, including: comprising a first portion of a first transmitting coil configured to generate a first magnetic field, comprising a second portion of a second transmitting coil configured to generate a second magnetic field, and a spacer between the first transmitting coil and the second transmitting coil, the spacer material magnetically insulating the second transmitting coil from the first magnetic field; wherein the first portion and the second portion are connected by a flexible connector; and Receiver, comprising: a first portion comprising a first receiving coil configured to generate an electric current when exposed to a magnetic field, a second portion comprising a second receiving coil configured to generate an electric current when exposed to a magnetic field, and A receiver spacer is positioned between the first receive coil and the second receive coil, the spacer material magnetically insulating the first receive coil from the second receive coil.

9. The system of claim 8, wherein the receiver spacer is tapered to orient the first receive coil at a non-zero angle relative to the second receive coil.

10. The system of claim 8, wherein the receiver spacer comprises a ferromagnetic material.

11. The system of claim 8, wherein the receiver spacer comprises a non-magnetic material.

12. The system of claim 8, wherein when one of the first transmitting coil and the second transmitting coil is aligned with one of the first receiving coil and the second receiving coil, a charging current applied to the transmitter induces an induced current in the receiver that is at least 15% of the charging current.

13. A method for providing power from an electronic device to an accessory device, the method comprising: At the electronic device: providing a first interrogation current to a first transmitting coil proximate to a first surface of the electronic device to generate a first magnetic field through the first transmitting coil, wherein a portion of the first magnetic field extends beyond the first surface; After terminating the first interrogation current to the first transmitting coil, providing a second interrogation current to a second transmitting coil proximate a second surface of the electronic device opposite to the first surface to generate a second magnetic field through the second transmitting coil, wherein a portion of the second magnetic field extends beyond the second surface; detecting an induced current in a receiving coil of the accessory device in response to one of the first magnetic field and the second magnetic field; as well as A charging current is selectively provided to the first transmitting coil when the induced current is detected in response to the first magnetic field and a charging current is selectively provided to the second transmitting coil when the induced current is detected in response to the second magnetic field.

14. The method of claim 13, wherein detecting the induced current comprises detecting a change in a transmission current of one of the first transmitting coil and the second transmitting coil when the first magnetic field or the second magnetic field is applied to the receiving coil.

15. The method of claim 13, further comprising: After detecting the induced current, providing a communication signal to one of the first transmitting coil and the second transmitting coil to generate a corresponding magnetic field; as well as An acknowledgement signal is received from the accessory device in response to the corresponding magnetic field.

16. The method of claim 13, wherein detecting the induced current comprises receiving a wireless data signal from the accessory device after the accessory device measures the induced current in the receiving coil.

17. The method of claim 13, wherein providing the charging current comprises providing a charging current ranging from 1 Watt (W) to 15 W.

18. The method of claim 13, wherein the first verification current and the second verification current are each less than the charging current.

19. The method of claim 13, further comprising using an alignment feature of the electronic device to align the first transmit coil or the second transmit coil with the receive coil.

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