Apple has Won a Patent for a Protective Layer that prevents Foldable Displays from cracking over time
Today the U.S. Patent and Trademark Office officially granted Apple a patent that relates to protective cover layer structures for portable electronic devices, and more particularly for flexible displays in relation to foldable devices.
Apple's patent specifically relates to protective cover layer structures for smartphones, and more particularly for flexible displays that could fold while being crack resistant.
Apple's granted patent specifically describes display modules and protective cover layer structures that may be implemented in curved, flexible, conformable and foldable display modules, and in particular with curved, flexible, conformable and foldable display panels.
Apple's patent FIG. 1 below is a schematic isometric view illustration of a protective cover layer; FIG. 2 is a schematic cross-sectional side view illustration of a bent protective cover layer.
Apple notes that typically, glass fracture initiates from the presence of micro-cracks. The hardcoat layer #104 in accordance with embodiments may fill pre-existing micro-cracks and also make it harder to initiate a crack.
Furthermore, the hardcoat layer may be engineered to have a sufficiently high hardness and tensile strength to function as an exterior protective coating for the electronic device, while being able to withstand more strain before fracture compared to the transparent support substrate #102. Thus, the hardcoat layer is sufficiently durable for high puncture and scratch resistance.
Apple's patent FIG. 4A above is a schematic top view illustration of crack propagation in a scratched transparent support substrate; FIG. 4B is a schematic top view illustration of crack propagation in a scratched transparent support substrate with hardcoat layer.
Apple's patent FIGS. 12A-12B above are schematic isometric view illustrations of an electronic device #1200 such as an iPhone. The display panel #150 and protective cover layer #100 may be curved, flexible, conformable and/or foldable. Apple's patent FIG. 12A illustrates an outward bending application, while FIG. 12B illustrates an inward bending application.
In Apple’s second granted patent for this invention, they added 16 new technical patent claims to better protect their invention. Below are just 3 of the new claims:
New Claim 1: “An electronic device comprising: a display panel; a protective cover layer over the display panel, wherein the protective cover layer includes a transparent support substrate and a hardcoat layer covering an exterior facing surface of the transparent support substrate; wherein the transparent support substrate is formed of a material selected from the group consisting of glass and sapphire, and the hardcoat layer includes a particle filler within a polymer matrix; and wherein the hardcoat layer is characterized by a lower elastic modulus than the transparent support substrate, the hardcoat layer has a thickness range of 1 .mu.m-200 .mu.m and the transparent support substrate has a thickness less than 150 .mu.m.”
New Claim 5: “The electronic device of claim 1, wherein the particle filler includes ceramic particles selected from the group consisting of Al.sub.2O.sub.3, MgAlO.sub.4, SiAlON, AlON, and ZrO.sub.2.”
New Claim #12: An electronic device comprising: a display panel; a protective cover layer over the display panel, wherein the protective cover layer includes a transparent support substrate and a hardcoat layer covering an exterior facing surface of the transparent support substrate; and wherein the hardcoat layer includes a polymer matrix and a particle filler dispersed in the polymer matrix, and a concentration of the particle filler is higher nearest the transparent support substrate and lower nearest an outer surface of the hardcoat layer.
For more details and to review the remaining 13 new patent claims, review Apple's granted patent 11,402,868.