When Tim Cook was in Japan in late December he visited 'Seiko Advanced,' an Apple partner for creating iPhone colored inks like the cool new Midnight Green for the iPhone 11 Pro as shown in our cover graphic. Seiko Advanced is able to make unique colors while not using heavy pollutants in the ink such as halogen. While that's impressive, a new patent application from Apple published today by the US Patent & Trademark Office reveals more about Apple's next-gen colored coatings.

Apple's patent filing notes that the housing of an electronic may have transparent housing structures such as walls formed of glass or sapphire.

The transparent housing structures may have a colored coating. The colored coating may cover a housing wall or may be patterned to form a logo or trim.

The colored coating may include a thin absorptive layer and a metal layer configured so that the coating exhibits a desired color. Adjustments to the colored coating such as adjustments to the thickness of the thin absorptive layer may be used to alter the color of the coating. If desired, a colored layer such as a layer of colored polymer may be incorporated into the colored coating to further adjust the color of the coating.

The colored coating may be formed on an inner or outer housing structure surface. The surface may have a texture to provide the coating with a matte appearance.

When formed on an outer surface, a transparent diamond-like carbon layer may be included in the colored coating to protect the colored coating from scratches. When formed on an inner surface, a passivation layer may be included on the inner side of the colored coating to prevent oxidation of the metal layer.

Apple notes that their color coatings could apply to not only the iPhone and iPad but also future devices like Apple Watch, a future headset of glasses, AirPods, a TV, a gaming device, an automobile and a MacBook.

Could you image how cool it would have been to order Midnight Green AirPods instead of boring white to match your new Midnight Green iPhone 11 Pro? Could you image one day having a Midnight Green MacBook?

While Aluminum is nice and traditional and unlikely to change, the thought of something different would be a breath of fresh air. The MacBook with an aluminum finish was first introduced back in February 2006. After 14 years, it would be nice to see something new, even if it's just a color.

In some arrangements, it may be desirable for some or all of the coated structures in the device to exhibit a matte appearance. As shown in FIG. 7, coating layer #32 may be provided with a matte appearance by texturing the inner surface of substrate (#30 - e.g., so that this surface has a root-mean-square surface roughness of at least 25 nm, at least 50 nm, at least 100 nm, less than 400 nm, less than 1600 nm, or other suitable surface roughness). This rough surface texture helps scatter ambient light that is reflecting off of the coating (#32) and thereby provides the coating with a matte appearance.

In some arrangements, it may be desirable for the colored coating to exhibit radio-frequency transparency. For example, in systems in which layer #30 forms an electronic device housing wall, it may be desirable to allow wireless power signals and/or radio-frequency antenna signals to be transmitted and/or received through layer (#30) and the colored coating on this layer.  

To enhance radio-frequency transparency for wireless communications and/or to support inductive wireless charging, conductive materials (e.g., metal layer 36) may be patterned to form isolated islands (e.g., rectangular pads or pads of other shapes such as triangles, hexagons, etc.) on the layer (#300.

The pads may be tiled in an array with rows and columns or other suitable patterns. A mesh of gaps (e.g., intersecting lines extending horizontally and vertically between rows and columns of pads or other thin elongated gap structures such as illustrative gaps G in FIG. 7) may be present in the patterned layer. These gaps are free of metal or other conductive material in layer (#36) and therefore block current flow (e.g., the gaps block eddy currents and prevent electromagnetic signal resonances from occurring).

In addition to or instead of patterning conductive layer(s) of material to form pads, layer conductivity can be reduced by using low-conductivity alloys. For example, layer #36 may be formed from a reflective alloy such as a metal-silicon alloy (e.g., aluminum silicon), or other metal which has a lower conductivity than pure aluminum.

Lower conductivity metals that may be used in forming layer #36 include titanium and tin. The use of a lower conductivity material for forming this layer (in alloy form or pure form) may enhance radio-frequency transparency for layer #36 when compared to arrangements in which pure aluminum is used in forming the layer.

Apple's patent application 20200015390 that was published today by the U.S. Patent Office was filed back in Q2 2019. Considering that this is a patent application, the timing of such a product to market is unknown at this time.

Patently Apple posted a patent application similar to today's back in September 2019 covering a matte finish for the backside of an iPhone.