Apple wants to replace mechanical keyboard switches with proximity sensors in its new device

Detailed in a patent published by the U.S. Patent and Trademark Office earlier this month, an Apple invention describes a method of decoupling a keyboard’s mechanical feel from its electrical functionality by using proximity sensors. The patent, titled “Depressible keys with decoupled electrical and mechanical functionality,” shows a computer keyboard that replaces common contemporary keyboards, which rely on electromechanical actuators to transmit key press signals to a central processing unit.

The components in modern keyboards typically incorporate multiple structures under a single keycap, such as a key travel mechanism, tactile feedback structure, and electrical contacts or electrodes. Due to tight space constraints in modern keyboards, especially laptop versions, the tactile feedback component is often nested within the key travel mechanism below the electrical traces. The parts sandwich inhibits independent component modification, as a manufacturer must rework the entire system to achieve different keyboard experiences. 

Users, on the other hand, have varying tastes when it comes to tactile feedback, as some prefer a slow, silent key press, while others prefer the clacking sounds with long throws.

To cater to individual user preferences, Apple proposed a method for decoupling the mechanical and tactile functionality of a key from its electrical functionality. To be more specific, the document replaces the electrical contacts and traces with non-contact proximity sensors, while travel mechanism and feedback structures remain intact.

In most of its embodiments, Apple's key design features a light emitter aimed at the reflective bottom surface of a keycap. An accompanying light detector, or central detector connected to a light guide, is used to generate an electrical signal in response to the received light. When processed by a keyboard controller, the signals can estimate force, velocity, and distance metrics to accurately determine when a key is pressed. By applying pre-determined thresholds to incoming signals, the invention can, in some cases, detect errant key presses and support force-sensitive input applications. 

Other embodiments include dynamic threshold adjustments on a per-key and per-application basis, which allows users to set one input level for word processing and another for gaming. The invention also includes contingencies for installing structures formed from materials capable of elastic deformation, such as an electroactive polymer or shape-memory metal. In some embodiments, users can adjust the feel of such components on the fly.

Though it’s unclear whether Apple will implement its customizable keyboard in a future Mac product, the company is expected to announce new Mac hardware at an upcoming event this month. 

Source: Apple Insider