The described embodiments relate generally to portable listening devices such as earbuds and other types of in-ear listening devices, and to cases for storing and charging such devices.
Portable listening devices can be used with a wide variety of electronic devices such as portable media players, smart phones, tablet computers, laptop computers and stereo systems among others. Portable listening devices have historically included one or more small speakers configured to be place on, in, or near a user's ear, structural components that hold the speakers in place, and a cable that electrically connects the portable listening device to an audio source. Other portable listening devices can be wireless devices that do not include a cable and instead, wirelessly receive a stream of audio data from a wireless audio source.
While wireless portable listening devices have many advantages over wired devices, they also have some potential drawbacks. For example, wireless portable listening devices, typically require a battery, such as a rechargeable battery, that provides power to the wireless communication circuitry and other components of the device. For many currently available wireless portable listening devices, charge can be restored to the rechargeable battery in the device by physically connecting the portable listening device to a power source, which typically requires that the wireless portable listening device have a pair of electrical contacts to receive the charge.
In many devices such electrical contacts are positioned within a receptacle connector in the wireless portable listening device. The receptacle connector typically includes a cavity in the wireless portable listening device that provides an avenue within which dust and moisture can intrude and damage the device. Furthermore, a user of the electronic device has to physically connect the charging cable to the receptacle in order to charge the battery. Some other wireless portable listening devices including charging contacts at an external surface of the device, which is a significant improvement with respect to moisture resistance and other potential problems as compared to internal contacts positioned within a receptacle connector cavity. Even external contacts, however, can still result in potential paths for moisture ingression under extreme conditions (for example, at the seams between the contacts and housing) and/or potential corrosion of the contacts when repeatedly exposed to corrosive liquids, such as sweat.