Apple Invents iDevice Displays that Remain Functional even when Wet
Apple Watch series 4 has water resistance at a higher level than previous generations. Today the US Patent & Trademark Office published a patent application from Apple titled "Finger Tracking in Wet Environment." Apple's patent-pending invention covers new ways to ensure that liquid on an iDevice multitouch display won't interfere with touch controls as they once did. Our cover graphic shows Apple's SVP Worldwide Marketing Phil Schiller talking about their new premium iPhones provide better liquid resistance, including spilt beer.
Touch screens can allow a user to perform various functions by touching the touch sensor panel using a finger, stylus or other object at a location often dictated by a user interface (UI) being displayed by the display device.
In general, touch screens can recognize a touch and the position of the touch on the touch sensor panel, and the computing system can then interpret the touch in accordance with the display appearing at the time of the touch. Thereafter, the computing system can perform one or more actions based on the touch.
In the case of some touch sensing systems, a physical touch on the display may not be needed to detect a touch. For example, in some capacitive-type touch sensing systems, fringing electrical fields used to detect touch can extend beyond the surface of the display, and objects approaching near the surface may be detected near the surface without actually touching the surface.
In reality, however, not all touches detected on a touch sensor panel are intended user input. For example, water on the surface of the touch sensor panel can be detected as a touch. In particular, water on a touch-sensitive surface in contact with a metal housing of the device or a finger can be grounded and appear as a touch by a finger. As a result, water (or other unintentional touches) can result in unintended behavior by the device. This can negatively affect user experience, particularly in wet environments.
Apple's invention relates to touch input processing for touch-sensitive devices, and more particularly, to filtering unintended contact detected on a touch-sensitive surface. In wet environments in particular, water (e.g., from rain, shower, sweat, etc.) on the touch-sensitive surface can be erroneously detected as touch input and degrade touch performance.
In some examples, input patches can be classified as touch patches or non-touch patches prior to computationally-intensive touch processing. Filtering out unintended touches classified as non-touch patches can reduce processing requirements and save power.
Additionally, classifying input patches can improve touch performance in wet environments.
In some examples, input patches can be classified as touch patches or non-touch patches based on characteristics of edge touch nodes. In some examples, input patches can be classified as touch patches or non-touch patches based on a state-based signal threshold.
Apple's patent FIGS. 6A and 6B illustrate exemplary representations of input patches including edge touch nodes corresponding to one or more edges of a touch-sensitive surface.
Apple further notes that patent FIG. 6A illustrates an input patch #602 on touch-sensitive surface #600. The input patch can correspond, for example, to an object covering a portion of a touch screen and touching multiple sides of the touch screen. For example, the input patch and touch-sensitive surface can correspond to an Apple Watch touch screen partially submerged in a liquid (e.g., water).
Apple patent FIGS. 14A-C presented below illustrate exemplary representations of input patches corresponding to floating water and one or more fingers on a touch-sensitive surface.
Apple's patent FIGS. 15A-C above illustrate another exemplary representation of input patches corresponding to floating water and/or one or more fingers on a touch-sensitive surface.
Apple states in their patent filing that floating or partially grounded liquids (e.g., water) can degrade touch performance. In some examples, floating or partially grounded water can interfere with the detection of a touchdown or a liftoff of a user's finger.
In some examples, floating or partially grounded water can interfere with the detection of a swipe gesture or cause a swipe gesture to be unintentionally canceled.
In some examples, floating or partially ground water can merge with a user's finger and offset centroid detection (causing unwanted jitter in the touch sensing system performance.
In some examples, small droplets of water along the edges of a touch sensor panel can be detected as false taps or swipes, for example.
In some examples, to improve performance in wet environments, input patches can be classified as touch or non-touch patches (or paths). Non-touch patches can be ignored which can reduce processing requirements for the touch sensing system and can improve touch detection performance in wet environments.
Apple's patent application 20180307374 was filed back in Q3 2017.
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