Today the U.S. Patent and Trademark Office officially published a patent application from Apple that relates to future foldable devices that widely cover iPhones, a hybrid tablet-notebook and more. More specifically, the patent covers a means of chemically creating textured glass near the fold to keep it from cracking and more. Earlier today, Ming-Chi Kuo posted a research note wherein he predicts that a foldable hybrid iPad-MacBook-like device may go into mass production in 2027.

Electronic Devices With Folding Displays Having Textured Flexible Areas

Apple's granted patent describes an electronic device that may be provided with a foldable housing that allows the device to fold and unfold about a bend axis. A flexible display may be mounted in the foldable housing. The flexible display may have an array of pixels forming a display panel. The display panel may be configured to bend along the bend axis as the device is folded.

The display panel may display images that are viewable through a transparent display cover layer that overlaps the display panel. The display cover layer may be formed from a layer of glass. An elongated groove or other recess may be formed in the layer of glass that runs parallel to the bend axis while overlapping the bend axis. The recess may form a flexible locally thinned portion in the glass layer. This thinned portion allows the display cover layer to bend as the foldable device is opened and closed. Polymer may be placed in the recess to help planarize the inner side of the display cover layer adjacent to the display panel.

To promote wetting and adhesion of the polymer in the recess and to help reduce reflections, the inner surface of thinned portion of the display cover may be provided with a rough texture.

The thinned portion may have variable-thickness portions that transition in thickness between a minimum thinned portion thickness associated with the thinnest area of the thinned portion and a maximum display layer thickness associated with non-thinned portions of the display cover layer.

Apple's patent FIG. 1 below illustrates device #10 that may be a cellular telephone, tablet computer, laptop computer and more; FIG. 2 is a perspective view of the electronic device in an illustrative configuration in which the device is a portable electronic device with a display that could be folded back on itself.  The ability to place the device in a folded configuration in this way may help make the device compact so that it can be stored efficiently. When it is desired to view images on display #14, the device may be unfolded about axis #28 to place the device in the unfolded configuration of FIG. 2. This allows the display to lie flat and allows a user to view flat images on the display. The ability to fold the display onto itself allows the device to exhibit an inwardly folding behavior. The display may be sufficiently flexible to allow the device to be folded outwardly and/or inwardly.

Further, polymer #50 may be deposited as a liquid in the groove formed from thinned portion (e.g., under a vacuum) and subsequently cured (e.g., by applying light such as ultraviolet light, by applying heat, by using catalyst, and/or by using other curing techniques). The polymer may be formed from a flexible material such as silicone or urethane acrylate (as examples).

The presence of the rough random texture in the surface may help adhere the polymer to display cover layer 14CG. The texture may also help create a gradual change in effective refractive index as layer 14CG transitions to the polymer thereby helping to index discontinuities that could lead to light reflections at the glass-polymer interface.

Apple's patent FIG. 9 above is a cross-sectional side view of a portion of inner surface #42 having an illustrative rough texture. This texture may be formed, for example, by using a silicone mold or other structure to nano-imprint photoresist with desired surface relief features followed by plasma etching of the surface through the textured photoresist

Finally, as shown in FIG. 10, the inner and/or outer surface of display cover layer #14CG (in portions #44 and/or other portions of layer 14CG) may be chemically strengthened to form strengthened surface layers #60. As an example, layer 14CG may be formed from a glass (e.g., aluminosilicate glass) that is chemically strengthened by performing an ion-exchange process on the glass. During the ion-exchange process, smaller ions in the glass are replaced with larger ions. For example, sodium in the glass at the surface of layer 14CG may be replaced by potassium. This creates compressive stress in treated surface layers #60 that helps the glass resist damage from scratching and other wear.

For full details including Apple's 20 new patent claims, review Apple's patent application 20240079442.