Prior to Apple's chapter with GT Advanced Technologies to produce sapphire glass for future devices, Apple had invented a new way of manufacturing near defect-free sapphire designed for iOS devices like the iPhone. In fact Apple has many patents relating improving and working with sapphire glass. Today, the U.S. Patent and Trademark Office published a patent application from Apple titled "Electronic Devices with Sapphire-Coated Substrates." The invention is designed to add a sapphire coating to future OLED displays like those that will begin shipping in 2017 and beyond. Our cover graphic reveals an Apple patent figure which implies that OLED displays may be headed for future Macs as well.

Apple invention covers an electronic device with a housing such as a metal housing in which a display is mounted. The display may be protected by a transparent cover layer. The transparent cover layer may include a laser-annealed sapphire coating on the outer surface of a transparent substrate (e.g., a glass substrate). The sapphire coating may provide the display with a hard, scratch-resistant outer surface. Display layers such as an organic light emitting diode (OLED) display module may be laminated to the inner surface of the transparent substrate.

The sapphire coating may be formed by coating a surface of a transparent substrate such as a glass substrate with a thin film of amorphous aluminum oxide and/or other materials such as aluminum oxygen nitride. The amorphous aluminum oxide may have a thickness between 0.01 microns and 10 microns or may have other suitable thickness. The amorphous aluminum oxide may be locally heated to transform the amorphous aluminum oxide into alpha-phase aluminum oxide (also known as sapphire).

Local heating may be achieved by laser annealing the aluminum oxide coating with a carbon dioxide laser. The laser may produce laser light having a wavelength (e.g., 10.6 microns) that is absorbed in the aluminum oxide coating without being absorbed by the glass substrate to avoid damaging the glass substrate during the laser annealing process. The laser annealing process may raise the temperature of the aluminum oxide to above 1000.degree. C. at which point the aluminum oxide becomes sapphire.

After the sapphire coating is formed on the glass substrate, the glass substrate may be assembled with other display layers to form a display. The display may be assembled with other components in a housing to form an assembled electronic device.

Apple's patent FIG. 7 is a diagram of an illustrative system in which laser-based local heating equipment is being used to transform an aluminum oxide coating on a substrate into crystalline sapphire with minimal thermal impact on the substrate; FIG. 6 is a diagram showing illustrative steps involved in forming an electronic device having a display cover layer formed from a sapphire-coated substrate; and FIGS. 2, 3 and 4 illustrate the range of products the new sapphire coating/OLED display could apply to.

Like all patents, Apple makes it clear that the invention could apply to a wide range of future devices such as Apple Watch, a television and other wearables.

Apple patent application 20160248051 was filed in February 2016. Considering that this is a patent application, the timing of such a product to market is unknown at this time.

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