Attachment with magnetic relay structure for wireless power transfer

Abstract

Devices in a wireless power system can be capable of operating with removable accessories such as cases. When an electronic device is coupled to a case, the device can transmit or receive wireless power through the case. The case can have a split-open shape with a front cover portion that covers a display of the electronic device. The case can have an embedded ferrimagnetic core that relays magnetic flux during wireless power transfer operations. A magnetic alignment structure in the case can position the ferrimagnetic core in the case in a high magnetic flux density region between the power transmitting device and the power receiving device. The ferrimagnetic core relays the magnetic flux between a transmitting coil in the power transmitting device and a receiving coil in the power receiving device. The ferrimagnetic core can be formed in a front, sidewall, or back wall of the case.

Description

[0001] This patent application claims priority to U.S. Patent Application No. 17 / 179,647, filed February 19, 2021, and U.S. Provisional Patent Application No. 63 / 034,544, filed June 4, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates in general to power systems, and more specifically to wireless power systems for charging electronic devices. Background Technology

[0003] In a wireless charging system, a wireless power transmission device, such as a charging pad or charging dock, wirelessly transmits power to a wireless power receiving device, such as a portable electronic device. The portable electronic device has a coil and a rectifier circuit. The coil of the portable electronic device receives AC wireless power signals from the wireless power transmission device. The rectifier circuit converts the received signal into DC power. Summary of the Invention

[0004] This invention relates to a wireless power system having a wireless power transmission device and a wireless power receiving device. The wireless power transmission device may include a coil and a wireless power transmission circuit coupled to the coil. The wireless power transmission circuit may be configured to transmit a wireless power signal using the coil. The wireless power receiving device may include a coil configured to receive a wireless power signal from the wireless power transmission device and a rectifier circuit configured to convert the wireless power signal into DC power.

[0005] Devices in a wireless power system may be able to operate with removable accessories such as a housing. When the electronic device is coupled to the housing, it can transmit or receive wireless power through the housing. The housing may have a split shape with a front cover portion that covers the display of the electronic device.

[0006] The removable accessory may have an embedded ferrimagnetic core that relays magnetic flux between adjacent electronic devices during wireless power transfer operation. A magnetic alignment structure within the housing positions the ferrimagnetic core in a high flux density region between the power transmitting device and the power receiving device. The ferrimagnetic core relays the magnetic flux between the transmitting coil in the power transmitting device and the receiving coil in the power receiving device.

[0007] A ferrimagnetic core may be formed in the front portion of a housing configured to cover a display of an electronic device. The ferrimagnetic core may also be formed in the sidewalls or rear wall of the housing. The housing may include a copper shielding structure surrounding the ferrimagnetic core. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of an exemplary wireless charging system including a wireless power transmission device and a wireless power receiving device according to one implementation scheme.

[0009] Figure 2 This is a circuit diagram of an exemplary wireless power transmission and reception circuit according to one implementation scheme.

[0010] Figure 3A and Figure 3B These are, respectively, a top side view and a cross-sectional side view of an exemplary device in a wireless charging system according to one embodiment.

[0011] Figure 4 This is a top view of an illustrative removable housing with a front cover portion according to one embodiment.

[0012] Figure 5 It is based on an implementation plan. Figure 4 An illustrative side view of the removable housing cross-section.

[0013] Figure 6 This is a perspective view of an exemplary wireless charging system according to one embodiment, which includes electronic devices and a removable housing excluding the front cover portion.

[0014] Figure 7 This is a side view of an exemplary wireless charging system according to one embodiment, having a wireless power transmission device directly adjacent to a wireless power receiving device.

[0015] Figure 8A and Figure 8B This is a side view of an exemplary wireless charging system according to one embodiment, having a removable housing inserted between a wireless power transmitting device and a wireless power receiving device.

[0016] Figure 9A and Figure 9B This is a top view of an exemplary removable cover according to one embodiment, showing a magnetic core for relaying magnetic flux between a wireless power transmitting device and a wireless power receiving device.

[0017] Figure 10 This is a side view of an exemplary wireless charging system according to one embodiment, having a removable housing with a ring-shaped magnetic core inserted between a wireless power transmitting device and a wireless power receiving device.

[0018] Figure 11 It is based on an implementation plan with Figure 10 A top view of an illustrative removable cap for a toroidal magnetic core of the type shown. Detailed Implementation

[0019] A wireless power system includes a wireless power transmission device that wirelessly transmits power to a wireless power receiving device. The wireless power transmission device can be a device such as a wireless charging pad, wireless charging dish, wireless charging stand, wireless charging station, or other wireless power transmission equipment. The wireless power transmission device can be a standalone device or integrated into other electronic devices such as laptops or tablets, cellular phones, or other electronic devices. The wireless power transmission device has one or more coils used in transmitting wireless power to one or more wireless power receiving coils in the wireless power receiving device. The wireless power receiving device is a device such as a cellular phone, watch, media player, tablet, a pair of earphones, remote control, laptop computer, electronic pen or stylus, other portable electronic devices, or other wireless power receiving equipment.

[0020] During operation, the wireless power transmitting device supplies an AC signal to one or more wireless power transmitting coils. This causes the coils to transmit the AC electromagnetic signal (sometimes called the wireless power signal) to one or more corresponding coils in the wireless power receiving device. The rectifier circuit in the wireless power receiving device converts the received wireless power signal into direct current (DC) power to power the wireless power receiving device.

[0021] In some cases, electronic devices may be coupled to a removable housing. When held by a removable housing, a portion of the housing may sometimes be inserted between the electronic device and an adjacent electronic device. In one example, the electronic device held by the housing may function as a power receiving device, and the adjacent electronic device may function as a power transmitting device. Similarly, the electronic device held by the housing may function as a power transmitting device, and the adjacent electronic device may function as a power receiving device. The presence of a removable housing may increase the distance between the coils in the wireless power receiving device and the wireless power transmitting device. To improve charging efficiency, the removable housing may include one or more magnetic cores (e.g., ferrite elements) to direct magnetic flux from the transmitting device to the receiving device.

[0022] Figure 1 An exemplary wireless power system (wireless charging system) is shown. For example... Figure 1As shown, the wireless power system 8 includes wireless power transmission devices (such as wireless power transmission device 12) and wireless power receiving devices (such as wireless power receiving device 24). Wireless power transmission device 12 includes control circuitry 16. Wireless power receiving device 24 includes control circuitry 30. The control circuitry in system 8, such as control circuitry 16 and control circuitry 30, is used to control the operation of system 8. This control circuitry may include processing circuitry associated with a microprocessor, power management unit, baseband processor, digital signal processor, microcontroller, and / or application-specific integrated circuit (ASIC) having processing circuitry. The processing circuitry implements desired control and communication features in devices 12 and 24. For example, the processing circuitry can be used to select coils, determine power transmission levels, process sensor data and other data, process user input, handle negotiations between devices 12 and 24, transmit and receive in-band and out-of-band data, perform measurements, and otherwise control the operation of system 8.

[0023] The control circuitry in system 8 can be configured to perform operations within system 8 using hardware (e.g., dedicated hardware or circuitry), firmware, and / or software. Software code used to perform operations within system 8 is stored on a non-transitory computer-readable storage medium (e.g., a tangible computer-readable storage medium) in control circuitry 8. Software code may sometimes be referred to as software, data, program instructions, commands, or code. The non-transitory computer-readable storage medium may include non-volatile memory such as non-volatile random access memory (NVRAM), one or more hard disk drives (e.g., disk drives or solid-state drives), one or more removable flash drives, or other removable media. The software stored on the non-transitory computer-readable storage medium can be executed on the processing circuitry of control circuitry 16 and / or 30. The processing circuitry may include an application-specific integrated circuit (ASIC) with processing circuitry, one or more microprocessors, a central processing unit (CPU), or other processing circuitry.

[0024] The power delivery device 12 can be a standalone power adapter (e.g., a wireless power delivery device including power adapter circuitry), a wireless charging pad or other device coupled via cable to a power adapter or other equipment, equipment already integrated into furniture, a vehicle, or other systems, a removable battery box, or other wireless power delivery equipment. In some cases, the power delivery device 12 can be a portable electronic device such as a cellular phone, watch, media player, tablet, a pair of earphones, a remote control, a laptop computer, an electronic pen or stylus, or other portable electronic devices. The power delivery device 12 may also be able to receive wireless power (and may have a power receiving component similar to that of the power receiving device 24).

[0025] The power receiving device 24 can be a portable electronic device such as a cell phone, watch, media player, tablet computer, a pair of earphones, remote control, laptop computer, electronic pen or stylus, other portable electronic device or other wireless power receiving equipment.

[0026] The power delivery device 12 may be coupled to a wall socket (e.g., an AC power source), may have a battery such as battery 18 for power supply, and / or may have another power source. The power delivery device 12 may have an AC-DC power converter, such as AC-DC power converter 14, for converting AC power from the wall socket or other power source into DC power. The DC power can be used to power the control circuitry 16 and other components within the device 12. In some cases, a single electronic device may be configured to function simultaneously as both a power receiving device and a power delivery device (e.g., the device has both power delivery circuitry and power receiving circuitry).

[0027] DC power can be used to power control circuitry 16. During operation, the controller in control circuitry 16 uses power delivery circuitry 52 to deliver wireless power to power receiving circuitry 54 of device 24. Power delivery circuitry 52 may have a switching circuit (e.g., an inverter circuitry 61 formed by switches such as transistors) that is switched on or off based on a control signal provided by control circuitry 16 to generate an AC current signal through one or more wireless power delivery coils, such as wireless power delivery coil 36. Coil 36 may be arranged as a planar coil array (e.g., in a configuration where device 12 is a wireless charging pad) or may be arranged to form a coil cluster (e.g., in a configuration where device 12 is a wireless charging pad). In some arrangements, device 12 may have only a single coil. In other arrangements, device 12 may have multiple coils (e.g., two coils, more than two coils, four or more coils, six or more coils, 2-6 coils, less than 10 coils, etc.).

[0028] When AC current passes through one or more coils 36, it generates an alternating electromagnetic (e.g., magnetic) field (wireless power signal 44), which is received by one or more corresponding receiver coils, such as one or more coils 48 in power receiving device 24. Device 24 may have a single coil 48, at least two coils 48, at least three coils 48, at least four coils 48, or other suitable number of coils 48.

[0029] When an alternating electromagnetic field (sometimes referred to as magnetic flux) is received by coil 48 (e.g., when magnetic flux passes through coil 48), a corresponding alternating current is induced in coil 48. A rectifier circuit, such as rectifier circuit 50 (which includes rectifier components, such as synchronous rectifier metal-oxide-semiconductor transistors arranged in a bridge network), converts the AC signal (the received AC signal associated with electromagnetic signal 44) received from one or more coils 48 into a DC voltage signal for powering device 24.

[0030] The DC voltage generated by rectifier circuit 50 (sometimes referred to as rectifier output voltage Vrect) can be used to charge batteries such as battery 58 and to power other components in device 24. For example, device 24 may include input-output device 56. Input-output device 56 may include input devices for acquiring user input and / or performing environmental measurements, and may include output devices for providing output to the user. For example, input-output device 56 may include a display for creating visual output, a speaker for presenting the output as an audio signal, LED status indicators and other light-emitting components for emitting light to provide status information and / or other information to the user, tactile devices for generating vibrations and other tactile outputs, and / or other output devices. Input-output device 56 may also include sensors for acquiring input from the user and / or for measuring the surrounding environment of system 8. Exemplary sensors that may be included in input-output device 56 include three-dimensional sensors (e.g., three-dimensional image sensors such as structured light sensors that emit a light beam and use a two-dimensional digital image sensor to acquire image data for a three-dimensional image from the light spot generated when the light beam illuminates a target; binocular three-dimensional image sensors that use two or more cameras in a binocular imaging arrangement to acquire three-dimensional images; three-dimensional lidar (light detection and ranging) sensors; three-dimensional radio frequency sensors; or other sensors that acquire three-dimensional image data), cameras (e.g., infrared and / or visible light cameras with corresponding infrared and / or visible digital image sensors, and / or ultraviolet light cameras), gaze tracking sensors (e.g., gaze tracking systems based on image sensors and (if needed) on light sources emitting one or more light beams, wherein the image sensor is used to track the one or more light beams after the user's eye reflects the light beam), and touch sensors. The input-output components include buttons, capacitive proximity sensors, light-based (optical) proximity sensors such as infrared proximity sensors, other proximity sensors, force sensors, sensors such as switch-based contact sensors, gas sensors, pressure sensors, humidity sensors, magnetic sensors, audio sensors (microphones), ambient light sensors, optical sensors for performing spectral and other measurements on a target object (e.g., by emitting light and measuring the reflected light), microphones for acquiring voice commands and other audio inputs, distance sensors, motion, position, and / or orientation sensors configured to acquire information about motion, position, and / or orientation (e.g., accelerometers, gyroscopes, compasses, and / or inertial measurement units including all of these sensors or a subset of these sensors), sensors such as buttons that detect button press inputs, joysticks with sensors that detect joystick movement, keyboards, and / or other sensors. Any of these input-output components (which form the load of device 24) can be powered by a DC voltage generated by rectifier circuit 50 (and / or a DC voltage generated by battery 58).

[0031] Device 12 may optionally have one or more input-output devices 60 (e.g., input devices and / or output devices of the type described in combination with input-output device 56). For example, device 12 may be a tablet computer including display 32 and one or more sensors.

[0032] Device 12 and / or device 24 can perform wireless communication using in-band or out-of-band communication. Device 12 may, for example, have a wireless transceiver circuit 40 that uses an antenna to wirelessly transmit out-of-band signals to device 24. Wireless transceiver circuit 40 can be used to wirelessly receive out-of-band signals from device 24 using an antenna. Device 24 may have a wireless transceiver circuit 46 that transmits out-of-band signals to device 12. Receiver circuitry in wireless transceiver 46 can use an antenna to receive out-of-band signals from device 12. In-band transmission between devices 12 and 24 can be performed using coils 36 and 48.

[0033] It is desirable that the power transmitting device 12 and the power receiving device 24 can communicate information such as received power and charge status to control wireless power delivery. However, this process does not need to involve the transmission of device identification information. Out of due care, it is important to note that, to some extent, if any implementation of this charging technology involves the use of device identification information (or more generally, personally identifiable information), implementers should follow privacy policies and practices generally considered to meet or exceed industry or governmental requirements for protecting user privacy. Specifically, identification information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of authorized use should be clearly explained to the user. Where possible, such identification information may be extracted, for example, by using some rather than all bits of the information bytes, such that the resulting identification is not globally unique, but is still sufficient to facilitate communication in a reasonable device use scenario.

[0034] The control circuit 16 includes an external object measurement circuit 41, which can be used to detect external objects adjacent to the device 12 (e.g., on top of the charging surface). Circuit 41 can detect foreign objects such as coils, paperclips, and other metallic objects, and can detect the presence of the wireless power receiving device 24 (e.g., circuit 41 can detect the presence of one or more coils 48). In an arrangement where the device 12 forms a charging pad, the charging pad may have a surface shape adapted to the shape of the device 24. If desired, the pad or other device 12 may have magnets (sometimes referred to as magnetic alignment structures) that removably attach the device 12 to the device 24 during the alignment of coils 48 with coils 36 to achieve efficient wireless charging.

[0035] During object detection and characterization operations, external object measurement circuitry 41 can be used to measure coil 36 to determine the presence of any device 24 on device 12. Additional coils (not for power transmission) and / or other additional sensors may be used for object detection and characterization operations if needed.

[0036] In an exemplary arrangement, the measurement circuit 41 of the control circuit 16 includes a signal generator circuit (e.g., an oscillator circuit for generating AC probe signals at one or more probe frequencies, a pulse generator capable of generating pulses to enable measurement of the pulse response to acquire inductance information, quality factor (Q-Factor) information, etc.) and a signal detection circuit (e.g., a filter, an analog-to-digital converter, a pulse response measurement circuit, etc.). During measurement operation, the switching circuit in device 12 (e.g., in the charging socket of device 12) can be adjusted by the control circuit 16 to switch each coil of coil 36 into use. When each coil 36 is selectively switched into use, the control circuit 16 uses the signal generator circuit of the signal measurement circuit 41 to apply a probe signal to that coil, while simultaneously using the signal detection circuit of the signal measurement circuit 41 to measure the corresponding response. The measurement circuit 43 in the control circuit 30 and / or the control circuit 16 can also be used to perform current and voltage measurements (e.g., so that this information can be used by device 24 and / or device 12).

[0037] Figure 2 This is a circuit diagram of an exemplary wireless charging circuit for System 8. (For example...) Figure 2 As shown, circuit 52 may include inverter circuitry such as one or more inverters 61 or other drive circuitry that generates a wireless power signal transmitted through an output circuitry including one or more coils 36 and capacitors such as capacitor 70. In some embodiments, device 12 may include a plurality of individually controlled inverters 61, each providing a drive signal to a corresponding coil 36. In other embodiments, a switching circuitry is used to share an inverter 61 among the plurality of coils 36.

[0038] During operation, control signals for one or more inverters 61 are provided by control circuit 16 at control input 74. Figure 2The example shows a single inverter 61 and a single coil 36, but multiple inverters 61 and multiple coils 36 can be used if desired. In a multi-coil configuration, switching circuitry (e.g., multiplexer circuitry) can be used to couple a single inverter 61 to multiple coils 36 and / or each coil 36 can be coupled to a corresponding inverter 61. During wireless power transfer operation, transistors in one or more selected inverters 61 are driven by AC control signals from control circuitry 16. The relative phase between the inverters can be dynamically adjusted (e.g., a pair of inverters 61 can produce in-phase or out-of-phase (e.g., 180-degree out-of-phase) output signals).

[0039] One or more inverters 61 (e.g., transistors or other switches in circuit 52) ​​are used to apply a drive signal to cause an output circuit formed by selected coils 36 and capacitors 70 to generate an AC electromagnetic field (signal 44), which is received by the wireless power receiving circuit 54 using a wireless power receiving circuit formed by one or more coils 48 and one or more capacitors 72 in device 24.

[0040] If needed, the control circuitry 16 can adjust the relative phase between the drive coils 36 (e.g., the phase of one coil in the coils 36 that is driven relative to another adjacent driven coil in the coils 36) to help enhance wireless power transfer between device 12 and device 24. A rectifier circuitry 50 is coupled to one or more coils 48 (e.g., a pair of coils) and converts the received power from AC to DC, providing a corresponding DC output voltage Vrect at the rectifier output terminal 76 for powering load circuitry in device 24 (e.g., for charging battery 58, for powering a display and / or other input-output devices 56, and / or for powering other components). A single coil 48 or multiple coils 48 may be included in device 24. In an exemplary configuration, device 24 may be a stylus or other portable device with at least two coils 48. These two (or more) coils 48 may be used together when receiving wireless power. Other configurations may be used if desired.

[0041] As previously described, in-band transmission using coils 36 and 48 can be used to transfer (e.g., transmit and receive) information between device 12 and device 24. In one exemplary configuration, frequency shift keying (FSK) is used to transfer in-band data from device 12 to device 24, and amplitude shift keying (ASK) is used to transfer in-band data from device 24 to device 12. Power can be wirelessly transferred from device 12 to device 24 during these FSK and ASK transmissions (e.g., at least a certain amount of wireless power is transferred during in-band communication, regardless of whether devices 12 and 24 have completed a handshake process and agreed on a sustained power transfer level). Although power transfer circuitry 52 drives an AC signal to one or more coils of coil 36 at a power transfer frequency to generate signal 44, wireless transceiver circuitry 40 can use FSK modulation to modulate the power transfer frequency driving the AC signal, and thereby modulate the frequency of signal 44. In device 24, coil 48 is used to receive signal 44. The power receiving circuit 54 uses the received signal on coil 48 and rectifier 50 to generate DC power. Simultaneously, the wireless transceiver circuit 46 monitors the frequency of the AC signal passing through one or more coils 48 and uses FSK demodulation to extract the transmitted in-band data from signal 44. This method allows FSK data (e.g., FSK data packets) to be transmitted in-band from device 12 to device 24 via coils 36 and 48, while simultaneously using coils 36 and 48 to wirelessly transmit power from device 12 to device 24.

[0042] In-band communication between device 24 and device 12 can utilize ASK modulation and demodulation techniques. Wireless transceiver circuitry 46 transmits in-band data to device 12 by using a switch (e.g., one or more transistors coupling coil 48 in transceiver 46) to modulate the impedance of power receiving circuitry 54 (e.g., coil 48). This, in turn, modulates the amplitude of signal 44 and the amplitude of the AC signal passing through one or more coils 36. Wireless transceiver circuitry 40 monitors the amplitude of the AC signal passing through one or more coils 36 and uses ASK demodulation to extract the transmitted in-band data from these signals transmitted by wireless transceiver circuitry 46. ASK communication allows ASK data bits (e.g., ASK data packets) to be transmitted in-band from device 24 to device 12 via coils 48 and 36, while power is wirelessly transmitted from device 12 to device 24 using coils 36 and 48.

[0043] The examples of FSK modulation for transmitting in-band data from power transmission device 12 to power receiving device 24 and ASK modulation for transmitting in-band data from power receiving device 24 to power transmission device 12 are merely illustrative. In general, any desired communication technology can be used to transmit information from power transmission device 12 to power receiving device 24 and from power receiving device 24 to power transmission device 12.

[0044] exist Figure 3A and Figure 3B In the exemplary configuration (sometimes described herein as an example), device 12 is a tablet computer or other device with a display. Device 12 can transmit wireless power to attached devices such as computer styluses. Users can use the stylus to draw or write on tablet 12 and provide other inputs to tablet 12.

[0045] Figure 3A This is a top view of device 12, and Figure 3B This is a cross-sectional side view of device 12. (Example) Figure 3A As shown, the tablet computer 12 may include a housing, such as housing 164 in which the display 32 is mounted. Additional input-output devices (such as buttons) may also be used to provide input to the tablet computer 12. The display 32 may be a capacitive touchscreen display or a display incorporating other types of touch sensor technology. The touch sensor of the display 32 may be configured to receive input from a stylus. The stylus may also receive wireless power from the device 12.

[0046] The stylus may have a cylindrical shape or other elongated body extending along a longitudinal axis. The stylus body may be formed from metal and / or plastic tubing, as well as other elongated structures. The stylus may have a tip including a conductive elastomer member detected by a touch sensor of the display in the tablet computer 12. If desired, the tip may include active electronics (e.g., circuitry that transmits signals capacitively coupled to the touch sensor of the display and signals detected as touch input on the touch sensor).

[0047] The stylus may include a shaft portion that couples a tip to an opposite end of the stylus. The opposite end may include a conductive elastomer member, active electronics (e.g., circuitry that transmits signals capacitively coupled to a touch sensor of a flat panel display and signals detected as touch input on the touch sensor), a button, a metal connector adapted to an external plug, or other input-output components.

[0048] A force sensor may be incorporated into the tip of the stylus and / or the opposite end of the stylus. The force sensor can be used to measure the force with which a user presses the stylus against the outer surface of the display of device 12. The force data can then be wirelessly transmitted from the stylus to tablet computer 12, allowing the thickness of the lines being drawn on the tablet display to be adjusted accordingly, or allowing device 12 to take other appropriate actions.

[0049] The casing 164 of the tablet computer 12, sometimes referred to as a package or housing, may be formed of plastic, glass, ceramic, fiber composite material, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or any combination of two or more of these materials. The casing 164 may be formed in a one-piece configuration in which a portion or all of the casing 164 is machined or molded into a single structure, or it may be formed using multiple structures (e.g., an internal frame structure, one or more structures forming the surface of the outer casing, etc.). Figure 3A and Figure 3B In this example, housing 164 includes a conductive peripheral sidewall structure 164W surrounding the periphery of tablet computer 12. If desired, housing 164 may include a conductive rear wall structure 164R opposite the display 32 (e.g., the conductive rear wall structure 164R may form the rear outer surface, side, or surface of tablet computer 12). If desired, the rear wall 164R and sidewall 164W may be formed as a continuous structure (e.g., in a monolithic configuration) or as separate structures. Openings may be formed in housing 164 to accommodate communication ports, holes for buttons, and other structures as needed. The rear wall 164R and / or sidewall 164W may be formed of a metal or dielectric material such as ceramic, plastic, or glass.

[0050] The display 32 may be a touchscreen display incorporating a layer of conductive capacitive touch sensor electrodes or other touch sensor components (e.g., resistive touch sensor components, acoustic touch sensor components, force-based touch sensor components, light-based touch sensor components, etc.), or it may be a non-touchscreen display. The capacitive touchscreen electrodes may be formed from an array of indium tin oxide pads or other transparent conductive structures.

[0051] The display 32 (sometimes referred to as a screen) may have an active area including an array of display pixels. The pixel array may be formed from liquid crystal display (LCD) components, electrophoretic pixel arrays, plasma display pixel arrays, organic light-emitting diode display pixels or other light-emitting diode pixel arrays, electrowetting display pixel arrays, or display pixels based on other display technologies.

[0052] A display cover layer can be used to protect the display 32. This display cover layer may be a layer of clear glass, translucent plastic, clear ceramic, sapphire, or other clear crystalline material, or one or more other optically transparent layers. The display cover layer may have a planar shape, a convex curved profile, a shape with planar and curved portions, a layout including a planar main region surrounding one or more edges (where a portion of one or more edges bends out from the plane of the planar main region), or other suitable shapes. The display cover layer may cover the entire front of the tablet computer 12 (e.g., the entire length dimension of the tablet computer 12 parallel to the y-axis and the entire length dimension of the tablet computer 12 parallel to the y-axis). Figure 3A and Figure 3B(Extending the width dimension along the x-axis). The sidewall 164W may extend from the back of the tablet 12 formed by the rear wall 164R to the display overlay (e.g., across the tablet 12 parallel to the x-axis). Figure 3A and Figure 3B (The height dimension extension along the z-axis). In another suitable arrangement, the display cover may cover substantially the entire front of the tablet computer 12 or only a portion of the front of the tablet computer 12. Openings may be formed in the display cover. For example, openings may be formed in the display cover to accommodate buttons. Openings may also be formed in the display cover to accommodate ports such as speaker ports.

[0053] The housing 164 may have four peripheral edges (e.g., sidewalls 164W). One or more wireless power transmission coils 36 may be mounted within the housing 164 behind the display 32. If desired, one or more wireless power transmission coils 36 may be mounted behind the display 32 and adjacent to one of the four peripheral edges. For example, one or more coils 36 may be mounted behind the display 32 within peripheral edge region 166, peripheral edge region 168, peripheral edge region 170, and / or peripheral edge region 172. When mounted behind the display 32, the coils 36 can wirelessly transmit power to the stylus through the display 32 when the stylus is placed on the surface of the display 32. In these examples, the transmission coils are positioned behind the screen such that the stylus is placed on the display area (active area) of the screen (e.g., the light-emitting area of ​​the screen) and receives wireless power through the display area during wireless charging. These examples are merely illustrative. In another possible implementation, the stylus can be placed in the boundary area of ​​the screen (passive area) during charging (e.g., a screen area without light-emitting pixels extending around one or more sides of the screen's perimeter), and can receive wireless power from the transmission coil through the boundary area. The boundary area can be interposed between the display area of ​​the screen and the edge of the electronic device.

[0054] Consider an example where a wireless power transfer coil 36 is formed within region 168 of a tablet computer 12. In this scenario, when it is desired to charge the stylus, the user can place the stylus within region 168 onto the surface of the display 32 (e.g., such that the stylus axis is positioned on the surface of the display 32 and in contact with it). Figure 3A (The y-axis is aligned). When the stylus is placed on the display 32 within area 168 (e.g., placed directly above the front of the electronic device), the wireless power receiving coil in the stylus (e.g., Figure 1 The coil 48 in the stylus can be aligned with the wireless power transmission coil 36 in region 168. When aligned, the wireless power signal 44 can be transmitted from the tablet 12 to the stylus. The wireless power received by the stylus can be used to power the battery (e.g., Figure 1The stylus (58) is charged. Once the stylus (58) is fully charged, the user can pick up the stylus and continue to use it to provide user input to the tablet computer (12).

[0055] If desired, alignment structures may be formed within regions 166, 168, 170, and / or 172 to help ensure that the receiving coil 48 on the stylus is aligned with the transmitting coil 36 on the tablet 12 when the stylus is placed on the surface of the display 32. Examples of such alignment structures include magnetic alignment structures, indentations or grooves formed on the front surface of the display 32, clamping structures, adhesive structures, or any other desired alignment structures. In the example where the transmitting coil is located within region 168, a magnetic alignment structure may be formed within or adjacent to region 168 and below the display 32, if desired. The magnetic alignment structure attracts conductive or magnetic structures on the stylus to snap and hold the stylus in the aligned position of coils 36 and 48.

[0056] If needed, one or more wireless power transmission coils 36 can be installed within the tablet 12 adjacent to the housing sidewall 164W, such as in... Figure 3B Within region 174. In scenarios where the housing sidewall 164W is formed of a conductive material, a dielectric window may be formed within the sidewall. A transmission coil 36 may be mounted behind the dielectric window to allow wireless power to be delivered to the stylus when the stylus is placed adjacent to the dielectric window or the dielectric sidewall.

[0057] Figure 3A and Figure 3B The examples are merely illustrative. If desired, one or more wireless power transfer coils 36 may be formed adjacent to the rear housing wall 164R to charge the stylus 24 through the rear housing wall 164R. In scenarios where the rear housing wall 164R is formed of a conductive material, a dielectric window may be formed within the rear housing wall 164R, and the coil 36 may transmit wireless power to the stylus through the dielectric window in the rear housing wall 164R. In another suitable arrangement, the rear housing wall 164R may be formed of a dielectric (e.g., a dielectric overlay forming the back of a tablet). Generally, the wireless power transfer coil 36 may be formed at any desired location along the display 32, along the housing sidewall 164W, and / or along the rear housing wall 164R. Positioning the transfer coil 36 along the periphery of the display 32, such as in regions 166, 168, 170, and 172, allows the stylus to be placed on the surface of the display 32 without obstructing excessive viewing area of ​​the display 32 (e.g., allowing the user to still view the image displayed on the display 32 while the stylus is being charged). However, in general, the wireless power delivery coil 36 can be located at any desired location along the surface of the display 32. The wireless power delivery coil 36 can be positioned along any of the four peripheral sidewalls 164W of the tablet computer 12.

[0058] In this example, the tablet computer is used as a wireless power transmission device that transmits wireless power to an external device such as a stylus. This example is merely illustrative. Alternatively, the tablet computer may include a power receiving coil for receiving wireless power. As an example, the power receiving coil (e.g., coil 48) may be positioned adjacent to a dielectric portion of the rear housing wall 164R.

[0059] like Figure 4 As shown, the wireless charging system may also include a removable cover 102. The removable cover 102 (sometimes referred to as a removable housing) may have any suitable shape that allows the cover 102 to fit into the device 12. Figure 4 In the example, cover 102 has a split shape (sometimes referred to as a split cover) with a rear portion 102R and a front portion 102F (sometimes referred to as a first portion and a second portion). The rear portion 102R may have a rectangular recess with a rear wall surrounded by peripheral sidewalls 102W or other suitable structures (strips, clamps, sleeves, corner recesses, etc.) that allow cover 102 to receive and couple to device 12.

[0060] The portion of cover 102 extending along the folding axis 122 between the rear portion 102R and the front portion 102F may have a hinge structure (e.g., a flexible cover material that serves as a hinge or other hinge structure that couples portions 102F and 102R while allowing these portions to rotate relative to each other). In some configurations, additional flexible portions may be provided. For example, the front portion 102F may have one or more flexible strips. Each flexible strip allows additional folds to be formed in cover 102 (e.g., to manipulate the cover into one or more support configurations and to support device 12 at a desired angle while cover 102 is coupled to device 12). Each flexible strip may extend parallel to the folding axis 122 from one side of the front portion 102F to the other side of the front portion 102F.

[0061] When protection of device 12 within cover 102 is required, device 12 (e.g., housing 164 of device 12) can be pressure-fitted into recesses formed by the sidewalls 102W and / or rear wall of cover 102. Device can be coupled to cover 102 using magnets, clamps, or strips, or otherwise. Cover 102 may be formed of fabric, leather, polymer, other materials, and / or combinations of these materials.

[0062] Figure 5 This is a cross-sectional side view showing the device 12 held in the removable cover 102. Figure 5In this configuration, the front portion 102F of the cover 102 is folded down and covers the front of the device 12. Therefore, the front portion 102F of the cover 102 covers the display (32) of the device 12. This protects the display from damage. In some arrangements, the device 12 may need to transmit and / or receive wireless charging signals through the cover 102. For example, a stylus may be configured to be placed on the display for wireless charging (e.g., in…). Figure 3A (In one of regions 166, 168, 170, and 172). Since the front portion 102F covers the display, the stylus can instead be placed on the front portion 102F of the cover 102, rather than directly above the front of the electronic device. The wireless power signal is then transmitted from the device 12 to the stylus (e.g., receiving device 24) through the cover 102.

[0063] The presence of a dielectric cover 102 between devices 12 and 24 during wireless charging can reduce charging efficiency (due to the increased distance between devices 12 and 24). To maintain charging efficiency between devices 12 and 24 with or without the cover 102, the cover 102 may include a ferrite element located in the front cover portion 102F. The ferrite element may overlap with the wireless charging area and serve to relay magnetic flux between the transmitting and receiving devices, as will be discussed in more detail later.

[0064] Figure 4 and Figure 5 The example of the removable housing 102 is merely illustrative, featuring a cover portion (102F) configured to fold over and cover the display of device 12. In some arrangements, the front cover portion 102F may be omitted from the removable housing. Figure 6 This type of arrangement is shown in the figure.

[0065] like Figure 6 As shown, the removable housing 102 may include a rear portion 102R (e.g., a rear outer shell wall configured to cover the device 12, sometimes referred to as the rear wall) and side walls 102W (e.g., four peripheral side walls extending from the rear wall). The side walls 102W may form recesses configured to receive and secure the device 12 within the removable housing 102. When protection of the device 12 within the housing 102 is required, the device 12 (e.g., the housing 164 of the device 12) may be pressure-fitted into the recesses formed by the side walls 102W of the housing 102. The device may be coupled to the housing 102 using magnets, clamps, or strips, or otherwise. The housing 102 may be formed of fabric, leather, polymer, metal, other materials, and / or combinations of these materials.

[0066] Generally, wireless power signals can be transmitted (e.g., transmitted or received) via cover 102. Consider device 12 via the edge of the device housing (e.g., Figure 3BAn example of transmitting wireless power signals to a stylus via region 174 of the cover 102. When the device is coupled to the removable housing 102, the stylus can be placed on the corresponding region 176 on the side wall 102W of the housing 102. The device 12 can transmit wireless power signals to the stylus via region 176 of the cover 102. The device 12 can also transmit wireless power signals to the stylus via the display area or boundary area of ​​the screen, and then via the front of the cover.

[0067] For example, a tablet computer may include a wireless power receiving coil located on its rear surface. In this case, the tablet computer acts as a wireless power receiving device and can receive wireless power from a wireless power transmitting device such as a wireless charging pad or wireless charging dish. The tablet computer may still be coupled to (e.g., Figure 4 and Figure 5 or Figure 6 The housing 102 (of the type shown) is used. When the tablet is coupled to the housing 102, the rear portion 102R of the housing can be inserted between the tablet and the wireless charging pad. Therefore, the tablet can receive wireless power signals through area 178 on the rear portion 102R of the housing 102.

[0068] Figure 7 An example of a wireless charging system 8 is shown, which has a wireless power receiving device directly adjacent to (without an intervening housing) a wireless power transmission device. As shown, a power transmission assembly 202 (e.g., part of a power transmission circuit 52) ​​is included within the wireless power transmission device 12. The power transmission assembly (sometimes referred to as an inductive power transmission assembly) includes a magnetic core 203 having a base 204, a first branch 206, and a second branch 208. A first coil 36-1 is wound around the first branch 206, and a second coil 36-2 is wound around the second branch 208. Coils 36-1 and 36-2 can be coupled to an inverter circuit (e.g., Figure 1 The inverter circuit can drive coils 36-1 and 36-2 to generate magnetic flux. During operation, the first coil 36-1 and the second coil 36-2 can be driven to generate magnetic flux with opposite polarities.

[0069] The magnetic core base 204 has a front surface 210 and a rear surface 212. Coils 36-1 and 36-2 may be circumferentially wound with corresponding branches 206 and 208 along the axis of the respective branch (e.g., in the direction in which the branch extends from the front surface 210 of the base 204). The coils may be wound from a single conductor, a multi-strand conductor with multiple wires connected in parallel, braided wire, Litz wire, conductive ink or conductive traces such as multilayer tracks on a printed circuit board, or other conductive elements suitable for forming coils.

[0070] A power receiving assembly 224 (e.g., part of power receiving circuitry 54) is included within wireless power receiving device 24. The power receiving assembly (sometimes referred to as an inductive power receiving assembly) includes a magnetic core 223 having a base 224, a first branch 226, and a second branch 228. A first coil 48-1 is wound around the first branch 226, and a second coil 48-2 is wound around the second branch 228. Coils 48-1 and 48-2 can be coupled to a rectifier circuit (e.g., Figure 1 The rectifier circuit converts the received AC signal from coils 48-1 and 48-2 into a DC voltage signal to power device 24.

[0071] The magnetic core base 224 has a front surface 230 and a rear surface 232. Coils 48-1 and 48-2 may be circumferentially wound with respective branches 226 and 228 along the axis of the respective branch (e.g., in the direction in which the branch extends from the front surface 230 of the base 224). Coils 48-1 and 48-2 may be wound from a single conductor, a multi-strand conductor with multiple wires connected in parallel, braided wire, Litz wire, conductive ink or conductive traces such as multilayer tracks on a printed circuit board, or other conductive elements suitable for forming coils.

[0072] Alignment structures such as magnetic alignment structures 214 and 234 may optionally be included in the system. Figure 7 As shown, the wireless power transmission device 12 may have a magnetic alignment structure 214. The wireless power receiving device 24 may have a magnetic alignment structure 234. Each magnetic alignment structure 214 in the transmission device may be magnetically coupled to a corresponding magnetic alignment structure 234 in the receiving device. When the transmitter alignment structure 214 is coupled to the receiver alignment structure 234, the transmission coil 36 may be aligned with the receiver coil 48. Therefore, the magnetic alignment structure ensures proper alignment of the receiver coil relative to the transmission coil. The magnetic alignment structures 214 and 234 may be permanent magnets (e.g., formed of a hard magnetic material that maintains their magnetic force over time).

[0073] Figure 7 The examples of power transmission and power receiving components shown are merely illustrative. In general, power transmission and power receiving components can have any desired design. In one alternative arrangement, the core of the power transmission and / or power receiving component may have a can-core design (e.g., a package with a toroidal hollow portion having a receiving coil). In yet another possible arrangement, the power transmission and / or power receiving component may include windings situated on a strip of ferrite. Any desired core and coil design can be used (e.g., U-shaped core, C-shaped core, E-shaped core, toroidal core, etc.).

[0074] Generally speaking, each device can have only one coil or two coils (e.g., Figure 7(e.g., three coils, more than three coils, etc.) One or two devices may include lateral coils (e.g., coils extending along the core base between two core branches). The precise geometry of the coils and cores in devices 12 and 24 can be customized according to specific designs. Wireless power receiving device 24 may be designed specifically to work with wireless power transmitting device 12. However, this is only illustrative. In some cases, power receiving device 24 may not be specifically designed to work with power transmitting device 12. Generally, each device may have different coil arrangements, different (or no) magnetic elements (e.g., cores), different coil and magnetic element sizes, different coil and magnetic element shapes, and other different characteristics.

[0075] exist Figure 7 In this configuration, the wireless power receiving device 24 is positioned directly above the wireless power transmitting device 12. For example, as shown, the outer surface 236 of the power receiving device 24 may be directly adjacent to and in direct contact with the outer surface 216 of the power transmitting device 12. This may occur, for example, when a stylus is placed on the outer surface of a tablet for charging (e.g., in combination). Figure 3A and Figure 3B (As discussed).

[0076] When the power receiving device 24 or the power transmitting device 12 is included within a removable housing, an intervening layer may exist between the outer surfaces of the power receiving device 24 and the power transmitting device 12 during charging. Figure 8A The diagram illustrates this type of arrangement.

[0077] like Figure 8A As shown, housing 102 can be inserted between wireless power transmitting device 12 and wireless power receiving device 24. The housing may contain dielectric material 262 (e.g., bulk dielectric material), such as fabric, leather, polymer (e.g., polyurethane), other materials, and / or combinations of these materials. The dielectric material 262 of housing 102 may have a thickness 260 between power transmitting device 12 and power receiving device 24. The greater the value of the thickness 260, the greater the separation between the power delivery assembly 202 in power transmitting device 12 and the power receiving assembly 222 in power receiving device 24. In the absence of any additional components in housing 102, this increased separation leads to a decrease in wireless power delivery efficiency between devices 12 and 24. However, as... Figure 8A As shown, housing 102 may also include embedded components that maintain wireless power transfer efficiency even in the presence of housing 102.

[0078] Housing 102 includes a magnetic core 252, which is inserted between the transmission coil 36-1 and branch 206 in the transmitting device 12 and the receiving coil 48-1 and branch 226 in the receiving device 24. Housing 102 also includes a magnetic core 254, which is inserted between the transmission coil 36-2 and branch 208 in the transmitting device 12 and the receiving coil 48-2 and branch 228 in the receiving device 24. Magnetic cores 252 and 254 have high permeability and therefore reduce the magnetic reluctance between the transmitting and receiving devices. Magnetic field lines pass through housing 102 and are concentrated in magnetic cores 252 and 254. In other words, magnetic cores 252 and 254 route magnetic flux from one surface of the housing (adjacent to the power transmission device) to the other surface of the housing (adjacent to the power receiving device). Therefore, magnetic cores 252 and 254 may sometimes be referred to as magnetic relays 252 and 254 (because they form a low-resistance path for relaying magnetic flux between the transmitter and receiver).

[0079] Magnetic cores 252 and 254 can be positioned in regions of housing 102 with high magnetic flux density during power transfer operations between devices 12 and 24. As shown, magnetic core 252 can overlap with branches 206 in device 12 and 226 in device 24, which can be regions with high magnetic flux density. Magnetic core 254 can overlap with branches 208 in device 12 and 228 in device 24, which can also be regions with high magnetic flux density. The cores can be embedded in dielectric material 262 such that magnetic cores 252 and 254 are completely surrounded by and in direct contact with dielectric material 262. This example is merely illustrative. In an alternative arrangement, the cores can be laterally surrounded by dielectric material 262 and can have one or more exposed surfaces on the upper / lower surface of housing 102.

[0080] The housing 102 may include a magnetic alignment structure 264 to ensure proper alignment between the power transmission assembly 202 and the power receiving assembly 222. The magnetic alignment structure 264 (which may be a permanent magnet) is magnetically coupled to a corresponding magnetic alignment structure 214 in the transmission device. The magnetic structure 264 may also be magnetically coupled to a corresponding magnetic alignment structure 234 in the receiving device. When the alignment structure 264 in the housing is coupled to the alignment structures 214 and 234, the transmission coil 36, the magnetic core 252, and the receiving coil 48 can all be aligned. Therefore, the magnetic alignment structure ensures proper alignment of the receiving coil relative to the transmission coil and proper alignment of the magnetic relays 252 and 254 relative to the coil.

[0081] Generally speaking, magnetic relays 252 and 254 can have any desired thickness and shape. The thickness and shape of each magnetic relay can be optimized to achieve the target magnetic properties within the system.

[0082] The example of using a magnetic alignment structure in housing 102 to ensure proper alignment between power delivery assembly 202 and power receiving assembly 222 is merely illustrative. Other types of alignment structures may be used for alignment structure 264 if desired (e.g., indentation or groove, clamping structure, adhesive structure, or any other desired alignment structure).

[0083] The magnetic cores described herein (e.g., 203, 223, 252, 254, 272, 274, and 276) may be formed from soft magnetic materials such as ferrite. The cores may have high permeability, allowing them to guide the magnetic field in a system. The examples using ferrite cores are merely illustrative. Other ferromagnetic and / or ferrimagnetic materials such as iron, low-carbon steel, high-permeability alloys (nickel-iron alloys), nanocrystalline magnetic materials, rare-earth metals, or other magnetic materials with sufficiently high permeability to guide the magnetic field in a system may be used for one or more cores. The core may sometimes be referred to as a ferrimagnetic core. Cores 203, 223, 252, 254, 272, 274, and 276 may be a single piece or made from individual components. Cores may be molded, sintered, laminated, formed from particles (e.g., ceramic particles) distributed in a polymer, or manufactured by other processes.

[0084] The housing 102 may also optionally include a shielding around each embedded magnetic core. Figure 8A Examples of shielding structures 256 formed by an annulus surrounding a magnetic core 252 and 258 formed by an annulus surrounding a magnetic core 254 are shown. Shielding structures 256 and 258 (sometimes referred to as shielding elements, shielding rings, etc.) may be formed of electromagnetic shielding materials such as copper, brass, nickel, silver, steel, etc. The shielding structures may be annular and may laterally surround the magnetic core. In other words, the magnetic core 252 is formed in an opening (sometimes referred to as a central opening) defined by the shielding ring 256, and the magnetic core 254 is formed in an opening defined by the shielding ring 258.

[0085] exist Figure 8A The examples of annular shields 256 and 258 are merely illustrative. The presence of shields affects the magnetic properties of the system. Therefore, the shape and thickness of each shield portion can be selected to optimize system performance. As an example, a shield inserted between cores 252 and 254 may be unnecessary. Therefore, in an alternative embodiment, the shield may be included only between the core and the adjacent permanent magnet 264. Figure 8B This is a cross-sectional side view showing an example of this type.

[0086] like Figure 8BAs shown, shield 256 is inserted between magnetic core 252 and permanent magnet 264. Shield 258 is inserted between magnetic core 254 and permanent magnet 264. Positioning the shields in this manner helps to isolate cores 252 and 254 from the permanent magnet without adversely affecting the transmission of magnetic flux within the system.

[0087] Figure 8B The diagram illustrates how shielding elements can also be incorporated into power transmission device 12 and / or power receiving device 24. As shown, shielding elements such as shielding elements 282, 284, and 286 can be incorporated around power transmission assembly 202. Shielding element 282 is inserted between magnetic core 206 and coil 36-1 and permanent magnet 214. Shielding element 286 is inserted between magnetic core 208 and coil 36-2 and permanent magnet 214. Similarly, shielding elements such as shielding elements 288, 290, and 292 can be incorporated around power receiving assembly 222. Shielding element 288 is inserted between magnetic core 226 and coil 48-1 and permanent magnet 234. Shielding element 292 is inserted between magnetic core 228 and coil 48-2 and permanent magnet 234. Similar to shielding elements 256 and 258, shielding structures 282, 284, 286, 288, 290 and 292 can be formed from electromagnetic shielding materials such as copper, brass, nickel, silver, steel, etc.

[0088] Separate shielding around the power transmission / reception components Figure 8B The examples shown are merely illustrative. Generally, power transmission / reception devices may include one or more shields in any desired configuration. For example, Figure 8B The shielding elements 282, 284, and 286 can be integrally formed into a single shielding element. One or more shielding elements in the power transmission assembly 202 and / or power receiving assembly 222 may optionally have the same footprint as the shielding elements in Annex 102. The shielding elements may overlap in the vertical direction, such as... Figure 8B As shown.

[0089] Figure 9A yes Figure 8A A top view of housing 102, showing an illustrative arrangement of components embedded within the housing. Figure 9A In the example, shielding structure 256 forms a ring around magnetic core 252. Shielding structure 258 forms a ring around magnetic core 254. When inserted between a power transmission device and a power receiving device, permanent magnet 264 can be coupled to a permanent magnet in the adjacent device and positions magnetic cores 252 and 254 in proper alignment. Magnetic cores 252 and 254 can be sized to accommodate potential alignment variations relative to adjacent devices.

[0090] The example of the magnetic alignment structure 264 being formed as two discrete parts on both sides of the magnetic core is merely illustrative. If desired, the magnetic alignment structure 264 may include annular permanent magnets laterally surrounding the magnetic core 252 / 254 and the shielding structures 256 / 258.

[0091] As previously mentioned, shielding structures 256 and 258 may have shapes other than annular. Figure 9B yes Figure 8B A top view of housing 102 shows an exemplary arrangement of components embedded within the housing. As shown, shield 256 can be inserted between core 252 and magnetic alignment structure 264. Shield 258 can be inserted between core 254 and magnetic alignment structure 264. This example is merely illustrative. In another possible configuration, a single annular (e.g., rectangular annular) shield structure can be formed around magnetic cores 252 and 254. However, in this embodiment, no shielding material is still formed between magnetic cores 252 and 254 (because shielding in this area may be detrimental to the magnetic properties of the system).

[0092] It should be noted that, Figure 8A , Figure 8B , Figure 9A and Figure 9B The specific examples of embedded components in housing 102 shown are merely illustrative. Generally, the size, shape, and positioning of the magnetic core in housing 102 depend on the design of the transmitting and receiving devices with which the magnetic core is intended to operate. The magnetic core can be embedded in various locations within housing 102. For example, the magnetic core can be embedded in the front cover portion 102F of a removable cover with a split shape (e.g., Figure 4 and Figure 5 (As shown). The magnetic core can be embedded in the front cover portion 102F to overlap with areas 166, 168, 170, or 172 of the tablet. In this type of design, the embedded magnetic core increases the charging efficiency of the tablet in transferring charge to a stylus placed at the front of the tablet.

[0093] However, the magnetic core can alternatively be embedded in the sidewall of the housing 102 (e.g., in...). Figure 6 In region 176, the magnetic core is used to enhance charging efficiency in an embodiment where the stylus is placed on the side wall of the tablet for wireless charging. Generally, the magnetic core can be formed in any part of the removable housing that is inserted between the device transmitting wireless power (e.g., the front of the removable housing, the side wall of the removable housing, or the rear wall of the removable housing).

[0094] Figure 10 and Figure 11 An alternative example of a design for an embedded magnetic core in housing 102 is shown. Figure 10In the power transmission device 12, a single coil 36 and a magnetic core 271 are included. The magnetic core 271 may have a base 272 and branches such as branches 280 (e.g., annular branches) that project towards the outer surface of the device 12 away from the base portion of the core. The power receiving device 24 also includes a single coil 48 having an associated magnetic core 274. A circular annular magnetic core 276 is embedded in the dielectric material 262 of the cover 102 to relay magnetic flux from the transmitting device toward the receiving device. The magnetic core 276 may have an annular shape aligned with the branches 280 of the magnetic core 271 in the transmitting device. Similar to Figure 8, Figure 10 The magnetic core 276 is positioned in a region of high magnetic flux density within the system (e.g., in the region of high magnetic flux density between devices 12 and 24). Thus, the magnetic core 276 functions as a relay and directs the magnetic field between transmitter 12 and receiver 24. Cover 102 also includes permanent magnets 264 to align the magnetic core 276 in the desired position and to align coil 36 with coil 48. In some examples, the core 276 is a continuous ring. In some examples, the core 276 comprises multiple discrete core portions arranged in an arcuate manner to form a ring.

[0095] As an example, Figure 10 This arrangement can be used in systems where the transmitting device 12 is a wireless charging pad or wireless charging tray. The wireless power receiving device 24 can be a portable electronic device, such as a cellular phone, tablet, etc. A portion of the housing 102 can be inserted between the inserted devices 12 and 24 during charging (e.g., Figure 6 (102R in the rear part of the middle).

[0096] Figure 11 This includes, for example Figure 10 A top view of the housing of the toroidal magnetic core. As shown, the magnetic core 276 is formed in a ring shape (e.g., aligned with branch 280 of the core 271 in the transmission device). The permanent magnet 264 may also have a ring shape concentric with the ring of the magnetic core 276. If desired, one or more rings of shielding material (e.g., copper shielding material or another shielding material similar to that discussed in conjunction with Figure 8) may be incorporated into the housing. The rings of the shielding material may be concentric with the magnetic core 276 and the magnetic alignment structure 264.

[0097] In summary, a removable housing can be coupled to an electronic device to protect and / or cover it. During wireless power transfer operation, a portion of the removable housing can be inserted between the electronic device and an attached electronic device. For example, the electronic device can transmit wireless power signals to the attached electronic device via a portion of the removable housing. Alternatively or additionally, the electronic device can receive wireless power signals from the attached electronic device via a portion of the removable housing. The wireless power signals can be transmitted and / or received through any desired portion of the removable housing (e.g., rear, front, sidewall portions, etc.). Wireless power signals can be transmitted and / or received through portions of the removable housing that overlap with the display area or boundary area of ​​the screen of the electronic device. To improve the efficiency of wireless power transfer when the removable housing is inserted between two devices, the removable housing may include one or more magnetic cores that relay magnetic flux from a first surface of the housing adjacent to the transmitting device to a second surface of the housing adjacent to the receiving device. Any desired type and shape of removable cover may include one or more magnetic cores to relay magnetic flux during wireless power transfer operation between two adjacent devices.

[0098] According to one embodiment, a cover for an electronic device having a front side is provided, the cover being configured to include: a rear cover portion configured to receive the electronic device; a front cover portion configured to move relative to the rear cover portion and configured to cover the front side of the electronic device; and a ferrimagnetic core embedded in the front cover portion, the ferrimagnetic core being configured to guide magnetic flux received from a first coil in the electronic device to a second coil in an additional electronic device.

[0099] According to another embodiment, the ferrimagnetic core is a first ferrimagnetic core, and the cover includes a first magnetic alignment structure located in the front cover portion, wherein when the first magnetic alignment structure is magnetically coupled to a second magnetic alignment structure in the electronic device and a third magnetic alignment structure in the additional electronic device, the first ferrimagnetic core is inserted between the second ferrimagnetic core in the electronic device and the third ferrimagnetic core in the additional electronic device.

[0100] According to another embodiment, the cover includes a shielding structure located in the front cover portion and inserted between the first ferrimagnetic core and the first magnetic alignment structure.

[0101] According to another embodiment, the shielding structure is a circular shielding structure that laterally surrounds the first subferromagnetic core.

[0102] According to another implementation, the shielding structure comprises copper.

[0103] According to another embodiment, the first magnetic alignment structure is a first permanent magnet, the second magnetic alignment structure is a second permanent magnet, and the third magnetic alignment structure is a third permanent magnet.

[0104] According to another embodiment, the ferrimagnetic core is a first ferrimagnetic core, and the cover includes a first alignment structure located in the front cover portion, wherein when the first alignment structure is aligned with a second alignment structure in the electronic device and a third alignment structure in the additional electronic device, the first ferrimagnetic core is positioned in a high magnetic flux density region between the electronic device and the additional electronic device.

[0105] According to another embodiment, the ferrimagnetic core is a first ferrimagnetic core, and the cover includes a second ferrimagnetic core embedded in the front cover portion, the second ferrimagnetic core being configured to direct magnetic flux received from a third coil in the electronic device toward a fourth coil in an additional electronic device.

[0106] According to another embodiment, the cover includes a first permanent magnet located in the front cover portion, a second permanent magnet located in the front cover portion, a first shielding structure inserted between the first ferrimagnetic core and the first permanent magnet, and a second shielding structure inserted between the second ferrimagnetic core and the second permanent magnet.

[0107] According to another embodiment, the first permanent magnet is configured to be magnetically coupled to a third permanent magnet in an electronic device, and the first permanent magnet is configured to be magnetically coupled to a fourth permanent magnet in an additional electronic device.

[0108] According to another embodiment, the additional electronic device includes a stylus, and when the front cover portion covers the front, the front cover portion is inserted between the front of the stylus and the front of the electronic device during wireless charging.

[0109] According to another embodiment, the stylus is configured to overlap with the display area of ​​the electronic device's screen during wireless charging.

[0110] According to another embodiment, the stylus is configured to overlap with the boundary area of ​​the electronic device during wireless charging, and the boundary area is interposed between the display area of ​​the screen and the edge of the electronic device.

[0111] According to another embodiment, the stylus and the electronic device are configured to transfer wireless power to each other when the stylus is placed directly above the front of the electronic device.

[0112] According to one embodiment, an accessory for an electronic device is configured to include: a dielectric layer inserted between the electronic device and the attached electronic device during wireless power transfer operations; a first magnetic alignment structure; and a first ferrimagnetic core located in the dielectric layer, the first ferrimagnetic core being inserted between the second ferrimagnetic core in the electronic device and the third ferrimagnetic core in the attached electronic device when the first magnetic alignment structure is magnetically coupled to a second magnetic alignment structure in the electronic device and a third magnetic alignment structure in the attached electronic device.

[0113] According to another embodiment, the annex includes a rear wall and peripheral sidewalls defining a recess configured to accommodate an electronic device.

[0114] According to another embodiment, one of the peripheral sidewalls includes a dielectric layer and a first ferrimagnetic core.

[0115] According to another embodiment, the rear wall includes a dielectric layer and a first ferrimagnetic core.

[0116] According to another embodiment, the first ferrimagnetic core is configured to relay the magnetic flux received from the first coil in the electronic device toward the second coil in the additional electronic device.

[0117] According to another embodiment, the first ferrimagnetic core is configured to relay the magnetic flux received from the first coil in the attached electronic device toward the second coil in the electronic device.

[0118] According to another embodiment, the annex includes a shielding structure located in the dielectric layer and inserted between the first magnetic alignment structure and the first ferrimagnetic core.

[0119] According to another embodiment, the first magnetic alignment structure is a circular permanent magnet with a central opening, and the first ferrimagnetic core is a circular magnetic core positioned in the central opening.

[0120] According to one embodiment, an electronic device capable of operating within a removable accessory having a magnetic relay structure is provided. The electronic device is configured to include: a housing configured to be coupled to the removable accessory; a display located within the housing; and a power transmission component located within the housing, the power transmission component including a ferrimagnetic core and a coil configured to transmit wireless power to the attached electronic device via the removable accessory, and the magnetic relay structure in the removable accessory being configured to relay magnetic flux from the coil toward an additional coil in the attached electronic device when the coil transmits wireless power to the attached electronic device.

[0121] According to another embodiment, the electronic device includes a permanent magnet configured to be magnetically coupled to an additional permanent magnet in a removable accessory to align the magnetic relay structure relative to the ferrimagnetic core and the coil.

[0122] The foregoing description is merely illustrative and various modifications can be made to the described implementation scheme. The described implementation scheme can be implemented independently or in any combination.

Claims

1. A cover for an electronic device having a front side, the cover comprising: Rear cover portion, the rear cover portion being configured to accommodate the electronic device; A front cover portion, the front cover portion being configured to move relative to the rear cover portion and being configured to cover the front of the electronic device; A ferrimagnetic core is embedded in the front cover portion, wherein the ferrimagnetic core is configured to guide magnetic flux received from a first coil in the electronic device to a second coil in an additional electronic device. A first magnetic alignment structure is located in the front cover portion; as well as A shielding structure located in the front cover portion, wherein the shielding structure is inserted between the ferrimagnetic core and the first magnetic alignment structure.

2. The cover according to claim 1, wherein the ferrimagnetic core is a first ferrimagnetic core, and When the first magnetic alignment structure is magnetically coupled to the second magnetic alignment structure in the electronic device and the third magnetic alignment structure in the additional electronic device, the first ferrimagnetic core is inserted between the second ferrimagnetic core in the electronic device and the third ferrimagnetic core in the additional electronic device.

3. The cover according to claim 1, wherein the shielding structure is a circular shielding structure that laterally surrounds the ferrimagnetic core.

4. The cover according to claim 1, wherein the shielding structure comprises copper.

5. The cover according to claim 2, wherein the first magnetic alignment structure is a first permanent magnet, wherein the second magnetic alignment structure is a second permanent magnet, and wherein the third magnetic alignment structure is a third permanent magnet.

6. The cover according to claim 1, When the first magnetic alignment structure is aligned with the second magnetic alignment structure in the electronic device and the third magnetic alignment structure in the additional electronic device, the subferromagnetic core is positioned in a high magnetic flux density region between the electronic device and the additional electronic device.

7. The cover according to claim 1, wherein the ferrimagnetic core is a first ferrimagnetic core, and wherein the cover further comprises: A second ferrimagnetic core is embedded in the front cover portion, wherein the second ferrimagnetic core is configured to direct magnetic flux received from a third coil in the electronic device toward a fourth coil in the additional electronic device.

8. The cover according to claim 7, further comprising: A second magnetic alignment structure is located in the front cover portion; as well as The second shielding structure is inserted between the second ferrimagnetic core and the second magnetic alignment structure.

9. The cover of claim 8, wherein the first magnetic alignment structure is configured to be magnetically coupled to a third magnetic alignment structure in the electronic device, and wherein the first magnetic alignment structure is configured to be magnetically coupled to a fourth magnetic alignment structure in the additional electronic device.

10. The cover of claim 1, wherein the additional electronic device includes a stylus, and wherein when the front cover portion covers the front surface, the front cover portion is inserted between the stylus and the front surface of the electronic device during wireless charging.

11. An accessory for an electronic device, the accessory comprising: A dielectric layer, which is inserted between the electronic device and the attached electronic device during wireless power transfer operations; First magnetic alignment structure; The first ferrimagnetic core is located in the dielectric layer. When the first magnetic alignment structure is magnetically coupled to the second magnetic alignment structure in the electronic device and the third magnetic alignment structure in the additional electronic device, the first ferrimagnetic core is inserted between the second ferrimagnetic core in the electronic device and the third ferrimagnetic core in the additional electronic device. as well as A shielding structure located in the dielectric layer, wherein the shielding structure is inserted between the first ferrimagnetic core and the first magnetic alignment structure.

12. The accessory of claim 11, wherein the accessory further comprises a rear wall and a peripheral sidewall defining a recess configured to receive the electronic device.

13. The attachment of claim 12, wherein one of the peripheral sidewalls comprises the dielectric layer and the first ferrimagnetic core.

14. The attachment of claim 12, wherein the rear wall comprises the dielectric layer and the first ferrimagnetic core.

15. The appendix of claim 12, wherein the first ferrimagnetic core is configured to relay magnetic flux received from the first coil in the electronic device toward the second coil in the additional electronic device.

16. The appendix of claim 11, wherein the first magnetic alignment structure is a circular permanent magnet having a central opening, and wherein the first ferrimagnetic core is a circular magnetic core positioned in the central opening.

17. An electronic device capable of operating within the appendix of any one of claims 11-16, the electronic device comprising: A housing configured to be coupled to the accessory; The display is located within the housing; as well as The power transmission component is located in the housing.

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