Over the years Apple has been fined or sued regarding systematically refusing to repair iPhones that were water damaged. Today the U.S. Patent and Trademark Office officially published a patent application from Apple that relates to the possibility of using 'optical touch sensors' on future iPhones and iPads that are insensitive to the presence of moisture. While that may not guarantee that they're future devices will be 100% waterproof, it's a concrete advance in allowing a user's touch not be affected by moisture. A second patent application regarding waterproofing published today even goes one step further. 

Apple's invention relates primarily to an iPhone having a touch sensitive display that is insensitive to the presence of moisture. The display may have a two-dimensional optical touch sensor such as a direct illumination optical touch sensor or a total internal reflection touch sensor. The optical touch sensor may be used to gather touch input not only in benign conditions (e.g., in the absence of water or other moisture), but also while the electronic device is immersed in water or otherwise exposed to moisture.

An array of pixels in the display may be used to display images. A display cover layer may overlap the array of pixels. One or more light sources may be included to illuminate an external object such as a finger of a user or a stylus when the object contacts a surface of the display cover layer. This creates scattered light that may be detected by an array of light sensors. The light sources and the light sensors may be mounted on a common substrate with the array of image pixels (which may be formed by crystalline semiconductor light-emitting diode dies).

In some embodiments, the light sensors (light detectors) and light sources can include photodiodes and light emitting diodes (LEDs) (e.g., standard LEDs, organic LEDs (OLEDs), micro-LEDs and the like). The LEDs and photodiodes can be configured in a direct illumination optical reflective touch mode to detect the presence of an object such as a finger or stylus by detecting modulated light generated by some of the LEDs and reflected off the object.

In some examples, interference filters may be included over the light sources and/or the light detectors to improve discrimination between a user's finger and water droplets. An interface between air and the display cover layer is characterized by a first critical angle. An interface between water and the display cover layer is characterized by a second critical angle. The interference filters over the light sources may have a greater transmission for light at the wavelength of interest (such as near-infrared light) at a first incident angle that is less than the first critical angle than at a second incident angle that is greater than the first critical angle. The interference filters over the light detectors may have a greater transmission for light at the wavelength of interest (such as near-infrared light) at a first incident angle that is greater than the second critical angle than at a second incident angle that is less than the second critical angle.

Direct illumination optical touch sensors and total internal reflection touch sensors both rely on light passing through the detection surface of a cover material located above the integrated touch screen to photodiodes located below the cover material. However, light impinging on the boundary between the detection surface and a medium above the detection surface (e.g., air, water, finger, or stylus), from either above or below the detection surface, can reflect off the boundary or be refracted as it passes through the boundary. In some instances, this reflected or refracted light can be detected and incorrectly identified as a touching object. Accordingly, in some embodiments of the disclosure, light illuminator angular filters can be employed within each LED component configured as an illuminator to limit the illumination angle of those illuminators, and light detector angular filters can be employed within each photodiode component configured as a detector to limit the detection angle of those detectors. Each angular filter acts as mask, including an inner mask baffle and an outer mask, that together effectively block or filter light transmitted, reflected or refracted within the cover material to facilitate a customized angular response that reduces or eliminates the false detection of water droplets on the touch surface.

Apple's patent FIG. 2 relates to an iPhone; FIG. 12 is a side view of an illustrative optical touch sensor when a display cover layer is contacted by a water droplet; FIG. 14 is a side view of an illustrative optical touch sensor showing critical angles associated with the optical touch sensor; and   FIG. 15 is a graph of intensity as a function of incident angle for light reflected from a finger and light reflected from a water droplet.

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This is an ongoing project at Apple. Last year Patently Apple posted a report on this with different patent figures as noted below. The 2023 patent went one step further in showing optical touch would work even under water.

Apple's 2023 patent illustrated the same patent FIG. 2 below that illustrates that the focus device of this patent in an iPhone display; Different from today's patent figures, FIG. 8 below illustrates a cross-sectional side view of an illustrative optical touch sensor arrangement based on total internal reflection.

Apple's 2023 patent FIGS. 17 and 18 above illustrates different patent figures from today's patent. It illustrates a top view of illustrative nanostructures that may be used in a metasurface grating to couple light into a display cover layer at a desired angle; FIG. 18 is a top view of illustrative nanostructures that may be used in a metasurface grating to redirect light propagating within a display cover layer.

To review the full details of today's invention, check out patent application 20240310959.

Lastly, in another patent application published today titled "Embedded Waterproof Membrane," it states that "In some embodiments, the electronic device (e.g., a smartphone, or a smartwatch) is used in an aquatic environment such as a pool, lake, river, or other aquatic environment. The membrane is a waterproof and air-permeable membrane that allows the air (e.g., including one or more gases) or sound waves to pass through, while preventing liquid penetration, to protect the transducer from intruding liquids such as water, oil, sweat, or other liquids." For more on this, review patent application 20240314479.