A new research note from KGI Securities analyst Ming-Chi Kuo has cited the upcoming ‘iPhone 5S’ could possible include a new sapphire glassed covered home button with a fingerprint sensor–but the button itself will be convex, instead of concave as seen in current models (via MacRumors). The theory behind a raised convex home button would be to allow room for the fingerprint sensor:
Convex home button creates space for fingerprint sensor; yield to improve. We think that a fingerprint sensor will be placed under the home button of iPhone 5S. However, assembling it could be difficult as the space under home button is limited as it already has to accommodate the Lightning connector, speaker and microphone. Thus, we think the shape of the home button could be changed from concave to convex to create more space for a fingerprint sensor.
Sapphire prevents home button from being scratched. A convex home button could be more easily scratched, so a harder material is required. We believe Apple will switch from plastic to sapphire, whose hardness is second only to diamond. Sapphire would protect the home button from being scratched and the fingerprint sensor from being damaged.
Sapphire is second in hardness only to diamond, which would protect the fingerprint sensor in a convex-shaped home button, as opposed to regular plastic.
Kuo notes Apple’s acquisition of AuthenTec last summer for its sensor technology will hold an advantage over competitors, as the latter’s TruePrint technology uses RF electric field sensors, which the company describes as “very small antennas,” and capacitive sensors to accurately measure the surface of the skin. This technique enables the sensor to read down to live skin cell layers which are unaffected by dry, oily or dirty skin, unlike typical optical or thermal recognition sensors.
Speculation of a new home button was earlier reported in May, as a rumour from TechNews based on Asian supply chain sources said Apple would implement a sapphire glass covered home button in its next model, with a built-in fingerprint sensor.
The use of sapphire glass is currently used to cover the outer lens of the iPhone 5 camera. If Apple were to include a convex home button in the next iPhone, which earlier was reported to be announced on September 10, it would be the first iOS device to feature a raised home button, breaking the trend of the original 2007 iPhone button design.