A newly-published patent application from Apple is generating some interest today for its description of a means to reduce the size of headphone jacks by using pogo pins instead of the traditional cantilevered metal strips for mediating electrical contacts with headphone plugs.
The invention disclosure comes as Apple continues to shrink the general overall size of its portable devices, with reducing thickness in particular being a focus for the company. As devices continue to shrink, certain physical features become limiting factors for further size reduction, as can be seen in the current iPod shuffle and iPod nano, where the thickness of the devices appears to be approaching the limits imposed by the need to accommodate the headphone jack.
Apple's new iPod shuffle (left) and iPod nano (right)
Apple points to the current "cantilever beam" design for headphone jack contacts as requiring significant space in two dimensions to accommodate the contacts while also requiring sufficient length to ensure the necessary leverage to maintain contact with the headphone plug.
Cross-section of headphone jack showing pogo pin contacts
Switching from the cantilever beam to a series of spring-loaded pogo pins lined up along the side of the headphone jack could allow the jack to essentially require space in only a single dimension, allowing for thinner device designs.
The pogo pins can be positioned in the audio jack using any suitable orientation. In some embodiments, the pogo pins can be positioned in substantially a single plane such that the pogo pins require space in a single dimension of the audio jack assembly. The pogo pins can be oriented substantially orthogonal to the audio jack cavity (e.g., such that the deflectable tips extend orthogonally into the cavity), or at an angle relative to the cavity walls.
The patent application was filed in June 2009 based on a provisional patent application filed in March of that year and is credited to Apple engineers Sean Murphy and John DiFonzo.
