Apple has looked at using single glass panels and touch-sensitive membranes to solve its butterfly keyboard problems, and may yet return to the idea for how it safeguards against dust damage in the mechanism.
Due to their design, keyboards are able to be affected by elements gumming up the mechanism, preventing the keys from smoothly lowering and raising when pressed.
While old-fashioned keyboards are less susceptible, the chiclet-style notebook keyboards, like the ones used in the MacBook Pro lineup, may be prone. They can easily be stopped from working efficiently if dust, crumbs, or liquids enter under the keys and impact the mechanism.
This issue was one reason why Apple introduced specifically its third-generation butterfly mechanism. That featured a silicone membrane used both to deflect dust and to quieten typing.
That was in 2018, but a year before, Apple had started filing patent applications for a different solution. The application and the design went through multiple revisions, but now the rather basically-named "Computer with Keyboard" patent has been granted.
Given that recent MacBook Pro models have reverted to a much more popular scissor mechanism, Apple may stick with that.
However, the glass panel keyboard described in the newly-granted patent does have potential advantages. It removes the need for loose keys or a switching mechanism at all.
The patent really describes how a keyboard could be created without moving components. In Apple's proposal, a glass sheet would be used in place of the movable keys, with raised sections to denote where each key is located.
As the user presses down on one of the raised key sections, the keyboard detects the force input to that, "key" and handles it in the usual way within an application.
The use of raised keys would enable the proposed keyboard to offer a form of tactile feedback to users, allowing users to know exactly where their fingers are placed in relation to the center of each key. While this is similar in concept to a virtual keyboard on a screen, such as on a smartphone or tablet, it is much harder to touch type on a virtual keyboard due to not being able to touch the keys.
To provide a level of springiness similar to a normal key's deflection, Apple suggests the use of a raised side wall around the raised key region, which can be configured to deform on input. In some elements, the keys can buckle, with a lower layer including elements to push the key back into place and to detect each press.
As the panel is glass, this can allow for the key symbols to be defined by a secondary display in the lower section of the notebook, making it relatively simple to change the keyboard layout to a different language or an application-specific version. Furthermore, side sections could be used as a form of trackpad alongside the keyboard element.
While the idea can certainly eliminate the potential for dirt-based keyboard mechanism failures, it also has a byproduct of potentially making the keyboard even thinner, allowing for a bigger battery to be included, or an overall slimmer notebook profile.
As Apple does file a number of patent applications on a weekly basis, the publication of an idea is not a guarantee the concept will appear in a future Apple product, but does suggest areas of Apple's interest.
This is far from the first keyboard-based patent Apple has applied for. In March 2018, it applied for a "keyless keyboard" that used a similar secondary touchscreen display in the lower section of a keyboard, but more talks about the use of flat touch panels than versions with keyboard-shaped raised elements.
In February of the same year, Apple was granted a patent for "Dual display equipment with enhanced visibility and suppressed reflections," again suggesting the use of a touch-enabled OLED display as a keyboard.
In August 2018, a trio of filings named "Device having integrated interface system" largely suggested the use of plastic or glass to alter the surrounding area of the MacBook keyboard, and even the keyboard itself, with touch-sensitive capabilities.
The patent is credited to three inventors, including the prolific Paul X. Wang. His previous related work includes a patent application regarding the use of a glass keyboard for strength.