On Tuesday, Apple was granted a patent for a multi-layered phone. On Thursday, the US Patent and Trademark Office published a patent application from Apple regarding the structure of a unique crack-resistant protective cover layer for future foldable devices such as the iPhone (flip phone), iPad (laptop hybrid), Macs and TVs.
Hybrid cover/window construction for flexible viewing applications
Apple’s invention is focused on correcting screen cracking issues found in some of today’s foldable devices which is preventing many consumers from buying the whole idea of foldable smartphones right now. The Apple patent specifically relates to the structure of the new protective cover layer for smartphones, and more specifically to flexible screens that can fold while resisting cracking.
The patent specifically describes display units and protective cover layer structures that can be implemented in curved, flexible, conformable and foldable display units, and in particular with curved, flexible, conformable and foldable display panels.
Apple patented FIG. 1 Below is a schematic isometric illustration of the protective cover layer; Figs. Figure 2 is a schematic illustration of the cross-section view of a bent protective cover plate.
Apple notes that glass breakage often starts with microcracks. Depending on models, the #104 hard coat may fill in pre-existing fine cracks and also make it more difficult for crack initiation.
Furthermore, the hard coat layer can be designed to have a high hardness and tensile strength high enough to act as a protective outer coating for an electronic device, while being able to withstand more stress before fracture than a clear No. 102 substrate backing. Thus, the hard coat layer is highly durable Sufficient for high puncture and scratch resistance.
Apple patented FIG. Figure 4A above is a top view diagram of crack propagation in a scratched transparent backing layer; Figs. 4B is a top-view schematic diagram of crack propagation in a hard-scratched transparent backing layer.
Apple patent fig. 12A-12B above are isometric schematic illustrations of electronic device #1200 such as the iPhone. Display plate #150 and protective cover plate #100 may be curved, flexible, conformable, and/or foldable. Apple patented FIG. Figure 12A shows the application of external bending, and Figure FIG. Figure 12b shows the application of internal bending.
Apple listed 20 technical points for this invention
- An electronic device consisting of: a display board; and a protective covering layer over the display board, in which the protective covering layer includes a transparent supporting substrate and a hard layer covering the outward facing surface of the transparent supporting substrate.
- … where the hard coat layer also includes a touch screen between the display panel and the protective cover.
- …as the hard coat layer has a lower modulus of elasticity than the clear backing layer.
- … where the thickness of the hard coat layer is 1-200 µm and the thickness of the clear backing substrate is less than 150 µm.
- … where the hard coat layer is on the surface of the transparent support substrate which has an area roughness (Ra) of 0.5 nm to 10 nm, and the outer facing surface of the hard coat layer has an area roughness greater than that of the layer. The transparent supporting substrate on which the hard coat layer is located.
- … where one or more of the lateral edges of the transparent supporting pillar are tapered.
- … where the side edges also consist of a polymer adhesion layer between the hard coat layer and the clear backing layer.
- … where the polymer adhesion layer is 1-10 µm thick.
- … where the transparent backing is made of a material selected from the collection consisting of glass and sapphire.
- The electronic device also consists of a smudge-proof coating on an exterior facing hard-coat coating.
- The electronic device hard coat has an elastic modulus range of 40 GPa-400 GPa.
- The electronic device hard coat is composed of a multi-layered structure of materials with different modulus of elasticity properties.
- The hard coat layer of the electronic device provides anti-reflective properties.
- The adhesion layer of the electronic device is a polymer adhesion layer.
- The display panel of the electronic device is flexible, and also includes a sleeve to contain the flexible display panel and a layer of protective cover.
For more details, see Apple Patent Application #US 20230011092 A1.
- Hoon Kim: Product Design – Special Projects Group
- Nikhil Kalyankar: Principal Technologist – Optical Coatings and Films
- Paul Drzaic: Director of Investigations Show
- Yasmin Afsar: Hardware Engineer, Emerging Display Technology
- Chang-Chia Huang: Senior Architect of Emerging Display
- Christopher Jones: Chemist/Materials Engineer
- Masato Kuwabara: Film Visual Engineer