The iPhone 5S is already out and many pair of eyes are now trained on the next big thing - the iPhone 6 release date on 2014 which is expected to deliver the real deal like major hardware upgrades and more of killer iOS 7 features.

Two of the latter are likely revealed in latest Apple patents that Patently Apple has gathered in Europe and the United States.

In the U.S, the tech giant is allegedly planning to use a new gadget manufacturing technique that will see extended use of sapphire on three iOS devices namely the rumoured iWatch, the next-generation iPads and the iPhone 6.

"Apple's patent application describes their method of fusing a sapphire laminate sheet to a device's cover glass," Patently Apple said on its report.

Regarded as Earth's second strongest element next to diamond, sapphire-coating on iPhone's front face will "provide a stronger glass that is ultimately scratch resistant." Note that in coming up with the iPhone 5 and iPhone 5S in 2012 and this year respectively, Apple had introduced sapphire to its supply chain.

In the iPhone 5, the rear camera lens was coated with sapphire while in the 5S the same material covers the new capacitive Home button, apparently to offer more robust protection against wear and tear on the same key.

Underneath the controller lies the Touch ID fingerprint scanner that restricts use of the 5S to non-owners.

Now in the iPhone 6, Apple is reportedly planning to cover the whole glass surface of the handset, a move that aims to render the device scratch resistant.

"The use of a sapphire outer surface with a glass inner surface for the display may be used in future iDevices where the two sapphire surfaces are laminated together with the glass providing support for the display and the sapphire providing scratch resistance and durability advantages," Patently Apple said.

The same technology, the report said, "includes lapping and polishing a second side of the sapphire sheet and chemically strengthening the glass sheet."

And while improving the handset's built and sturdiness, Apple is also mulling inner enhancement, highlighted by the upgrade of the Notes application within the new iOS 7 environment.

In a separate report, Patently Apple tipped on the likelihood of iPhone 6 users enjoying text-to-speech conversion within the Notes app very soon. This cutting-edge capability is described in Apple's new patent filing in Europe, the Apple-focused tech site said.

"In the future, Apple's current invention will enable a user to select, from among multiple languages, a language to be used for performing text-to-speech conversion," said the report.

In the envisioned implementation, "multiple languages may be displayed to the user. The user may then select a particular language to be used from the multiple languages. The user-selected language may then be used to generate speech for text to be converted to speech."

These two killer features are expected to join the more powerful specs that according to analysts will be served by Apple via the iPhone 6 release date, pegged to materialise between January and March 2014.