US-12627170-B2 - Inductive coil assemblies for electronic devices and accessories

Abstract

Inductive coil assemblies for wireless power transfer can be provided for an electronic device having a slot to receive an accessory and an accessory having an attachment region that is insertable into the slot. The inductive coil assembly of the device can extend along a sidewall of the slot. The inductive coil assembly of the accessory can extend along one side surface of the attachment region of the accessory. The opposite sidewall of the slot and side surface of the attachment region of the accessory can provide mechanical retention features.

Inventors

• Daniel J. Hiemstra
• Zaki MOUSTAFA
• Zelin Xu

Assignees

• APPLE INC.

Dates

Publication Date

20260512

Application Date

20220923

Claims (17)

1. 1 . An electronic device comprising: a housing having a wall, the wall having a slot formed therein to receive at least a portion of an accessory, the slot having first and second opposing sidewalls that extend along a lateral direction; an inductive coil assembly positioned in a recess in the first sidewall, wherein the inductive coil assembly includes: a ferrite core; and a wire wrapped helically around at least a portion of the ferrite core; and a magnetically permeable cap that forms a portion of the first sidewall of the slot and that covers the ferrite core; and an active electronic component disposed within the housing and coupled to the inductive coil assembly.
2. 2 . The electronic device of claim 1 further comprising: an accessory retention feature disposed in the second sidewall of the slot.
3. 3 . The electronic device of claim 2 wherein the accessory retention feature includes a release button that extends from the second sidewall to a rear surface of the housing.
4. 4 . The electronic device of claim 1 wherein the second sidewall of the slot has an opening extending through to a rear surface of the housing and wherein a plug is sealed into the opening.
5. 5 . The electronic device of claim 4 wherein the plug is made of same material as the wall.
6. 6 . The electronic device of claim 1 further comprising an accessory having an attachment region insertable into the slot such that a first side surface of the attachment region is oriented toward the first sidewall of the slot and a second side surface of the attachment region is oriented toward the second sidewall of the slot, wherein: the accessory includes an inductive coil assembly positioned in the attachment region and oriented toward the first side surface; and the accessory further includes a retention feature positioned in the attachment region and oriented toward the second side surface.
7. 7 . The electronic device of claim 6 wherein the accessory is a band usable to secure the electronic device to a wrist of a user.
8. 8 . An accessory for an electronic device, the accessory including: a body having an attachment region insertable into a slot of an electronic device, the attachment region having a first side surface and a second side surface opposite the first side surface; an inductive coil assembly positioned in the attachment region and oriented toward the first side surface, the inductive coil assembly including: a ferrite core; a coil of wire wrapped helically around at least a portion of the ferrite core; and a protective cap made of a magnetically permeable material that forms a portion of the first side surface and that covers the ferrite core; and a retention feature positioned in the attachment region and oriented toward the second side surface.
9. 9 . The accessory of claim 8 further comprising: an active electronic component disposed within the body and coupled to the inductive coil assembly.
10. 10 . The accessory of claim 9 wherein the active electronic component is configured to operate the inductive coil assembly to receive power wirelessly from the electronic device.
11. 11 . The accessory of claim 9 wherein the active electronic component is configured to operate the inductive coil assembly to transmit power wirelessly to the electronic device.
12. 12 . An electronic device comprising: a housing having a wall, the wall having a slot formed therein to receive at least a portion of an accessory, the slot having first and second opposing sidewalls that extend along a lateral direction; an inductive coil assembly positioned in a recess in the first sidewall; and an active electronic component disposed within the housing and coupled to the inductive coil assembly, wherein the second sidewall of the slot has an opening extending through to a rear surface of the housing and wherein a plug is sealed into the opening.
13. 13 . The electronic device of claim 12 further comprising: an accessory retention feature disposed in the second sidewall of the slot.
14. 14 . The electronic device of claim 13 wherein the accessory retention feature includes a release button that extends from the second sidewall to a rear surface of the housing.
15. 15 . The electronic device of claim 12 wherein the plug is made of same material as the wall.
16. 16 . The electronic device of claim 12 further comprising an accessory having an attachment region insertable into the slot such that a first side surface of the attachment region is oriented toward the first sidewall of the slot and a second side surface of the attachment region is oriented toward the second sidewall of the slot, wherein: the accessory includes an inductive coil assembly positioned in the attachment region and oriented toward the first side surface; and the accessory further includes a retention feature positioned in the attachment region and oriented toward the second side surface.
17. 17 . The electronic device of claim 16 wherein the accessory is a band usable to secure the electronic device to a wrist of a user.

Description

BACKGROUND This disclosure relates to wearable electronic devices and in particular to inductive coil assemblies that enable power transfer between the main body of an electronic device and an attached band or other attachment member. Wearable electronic devices, such as smart watches and fitness trackers, have become popular. Some devices can include a main body that incorporates electronic components, display, speakers, user input controls, and the like. The main body can be attached to a band, such as a wrist strap, that allows the device to be worn by a user. Depending on the particular implementation, wearable devices can provide various capabilities, such as communication (e.g., phone calls, text messages, email), biometric monitoring (e.g., heart rate, pulse oximetry), navigation (e.g., using global positioning satellite system signals), media playback, and so on. In some wearable devices, the band (or other attachment member) may be detachably coupled to the main body. For example, the end walls of the main body may have slots that allow a band to be attached or detached by lateral sliding. To secure the band in the slot, the band can include a retention feature such as compressible tooth that is biased proud, and the main body can include a release button having a rest position that creates a recess in a sidewall of the slot. When the band is in position in the slot, the tooth extends into the recess to secure the band. The user can press the release button to push the tooth out of the recess and enable sliding. In this manner, the user can wear the same device with different bands at different times. SUMMARY To extend or enhance the functionality of an electronic device, it may be desirable to provide active electronic components in an accessory that can be attached to the electronic device. Such components may consume or produce power, and it may be desirable to transfer power between an accessory and an electronic device. In some cases, however, the interface area between the accessory and the electronic device may be limited. For example, the accessory may be insertable into a slot in the body of the electronic device, and the interface area may be limited to the area of the slot. The small area may limit or prohibit the use of electrical contacts such as pads or pins made of conductive material. In addition, it may be desirable for any electrical connections to be water-resistant in order to avoid damage or malfunction in the event that the device and/or accessory is exposed to moisture (e.g., perspiration or immersion in water). Inductive power transfer, in which power is transferred between respective wire coils (referred to as “inductive coils”) in the two devices using electromagnetic induction, does not require any exposed electrical contacts. However, the amount of power that can be transferred inductively can be limited by, among other factors, the size of the coils and the distance between the coils. In the case of an accessory secured in a slot of a device, the interface area is defined by the slot dimensions. A portion of the interface area may be dedicated to mechanical retention features that secure the accessory to the device (such as a tooth and button). Accordingly, the space available for inductive charging coils in the device and accessory may be limited. Certain embodiments of the present invention provide inductive coil assemblies and arrangements that can provide wireless power transfer between a device having a slot to receive an accessory and an accessory having an attachment portion that is insertable into the slot. In some embodiments, an inductive coil assembly in a main device body (such as a watch body) can extend along a sidewall of a slot into which an accessory (such as a band) is insertable. The accessory can have an attachment region (e.g., a region at an end of a band) that inserts into the slot (e.g., by lateral sliding). An inductive coil assembly can extend along one side surface of the attachment region of the accessory. When the accessory is attached to the main device body by inserting the attachment portion into the slot, the two inductive coil assemblies are brought into close proximity, allowing power transfer to occur. The opposite sidewall of the slot and the opposite side surface of the attachment region of the accessory can provide retention features (such as a recess and tooth) to provide mechanical retention. Some embodiments relate to an electronic device. In various embodiments, an electronic device can have a housing having a wall, the wall having a slot formed therein to receive at least a portion of an accessory, the slot having first and second opposing sidewalls that extend along a lateral direction. An inductive coil assembly can be positioned in a recess in the first sidewall. An active electronic component disposed within the housing and coupled to the inductive coil assembly. An accessory retention feature can be disposed in the second