We’ve previously noted KGI Securities’ Ming-Chi Kuo for his often accurate reports on upcoming Apple products in the past. Usually those reports revolve around features that have been somewhat expected. We’ve expected a fingerprint scanner for quite some time and even found code that seems to point to a biometric input for the new iPhone. We’ve also profiled possible fingerprint readers in the iPhone 5S just last week.

Today’s report is something a bit out of left field however. Kuo expects the iPhone 5S to have a sapphire fingerprint reader home button that will no longer be plastic and concave but actually protrude slightly from the iPhone in a convex manner. This isn’t the first we’ve heard of Sapphire home buttons but the first reputable source on the matter. Kuo

Previous reports had pointed to a fingerprint scanner below the screen of the iPhone.  Because the convex home button feature would leave the part prone to breaking and scratching, the home button will be made from sapphire, one of the most scratch resistant materials known to man, according to the report.

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.

Current iPhone 5’s use sapphire as a lens covering for the backside camera. What would be the advantages to Sapphire on the front as opposed to below the screen or in the back? Kuo:

The new home button would be an important differentiator, according to the report, and would mark the first significant physical change in an S iPhone in Apple’s recent product lines.

Design advantage of fingerprint reader on iPhone is ease of use. Unlike Android phones and Windows Phone, iPhone has only one home button on its cover glass. This design is intuitive for the behavior of using fingerprint sensor as users won’t be confused as to where to put on their finger.

Advantages in both technology & design. We think iPhone will continue to lead Android phones and Windows Phone by a wide margin in fingerprint sensing technology and design. As such, Apple will likely be able to offer users a more secure and more intuitive way to conduct mobile payment transactions and access cloud computing services, thereby strengthening advantages of the ecosystem.

Kuo thinks that iPhone 5S’s sapphire home button with fingerprint sensors will be adopted by other iOS devices in 2014 and “will generate fresh momentum for sapphire and fingerprint sensor suppliers”.

With last year’s Authentec acquisition and the recent rumors and evidence, it seems likely that a fingerprint sensor will be this year’s “Siri.”

Besides the fingerprint sensor, the next iPhone will likely sport the same design as the iPhone 5 (with the phone likely to be dubbed “iPhone 5S”), an improved camera system, and a faster, A7 processing chip. We heard just a few hours ago that the announcement would happen on September 10th and the rollout would likely take place in the following weeks. 

  • Rumored iPhone 5S production shots & specs: IGZO display, Fingerprint, NFC, 12MP cam (9to5mac.com)
  • Rumored iPhone 5S fingerprint sensor more likely to be in the screen, not the home button (9to5mac.com)
  • New mockups claim to show ‘iPhone 5S’ and ‘iPhone 5C’ designs [Gallery] (9to5mac.com)
  • New iPhone 5S photos reveal little new about the device (9to5mac.com)
  • An in-depth look at the technology behind fingerprint sensors in light of ‘iPhone 5S’ rumors (9to5mac.com)
  • Fingerprint sensors the new black for smartphones as Korean firm Pantech launches the first (9to5mac.com)
  • Apple patent application describes fingerprint sensor tech rumored for iPhone 5S (9to5mac.com)
  • iPhone 5S production now definitely starting this month. Maybe. (9to5mac.com)
  • Smartphone fingerprint sensors are the new black as Pantech beats the big boys (9to5google.com)
  • Digitimes: Initial ‘iPhone 5S’ shipments to be constrained as fingerprint sensors hit low yield-rates (9to5mac.com)