Apple's patent application, titled "Devices and methods for providing access to internal component," offers a method to conceal components that are needed only temporarily or go largely unused, cleaning up the overall appearance of the device.
Most noteworthy are so-called "visually-dependent components" which "traditionally required external exposure to light or that emit light." Examples are biometrics, or fingerprint readers, flashes, cameras and light sensors, among others.
Hidden camera and fingerprint sensors.
It seems that the invention is skewed toward a device's aesthetic appearance, as noted in the patent's background:
Furthermore, under the current techniques, adding new components may harm the aesthetic appeal of the device by cluttering the electronic device enclosure, even though these additional components may be seldom or never used by many users. An electronic device that incorporates multiple components may lose its aesthetic appeal when covered by visible components, particularly as compared to a seamless electronic device where very few, if any, components of the electronic device are visible.
With devices coming in ever smaller packages, and in the case of the iPhone with few visible components besides the screen, the task of incorporating additional hardware features without sacrificing design has become increasingly difficult.
What Apple proposes is a system to conceal integral parts that may need to sit near the device's surface for easy access. This system can temporarily or permanently hide a component depending on how often the user chooses to activate its corresponding feature, such as a fingerprint reader. The invention can be further implemented to cover camera assemblies or other commonly-used components to make a device appear monolithic in construction.
Back of iPhone with hidden camera array and flash.
Some current portables made by various electronics manufacturers employ similar techniques, for example a smartphone's dedicated capacitive buttons can be "lit up" by LED backlighting when not in use. This methodology doesn't truly hide a component, however, but instead selectively reveals a specific activated area of a touch sensitive surface that is technically never obscured from view.
Apple's solution calls for a polymer dispersed liquid crystal (PDLC) window, or similar technology, "that can change between opaque and transparent configurations," allowing components to seemingly "appear as from out of nowhere."
Powering the window would be the window controller, which determines when to transition the unit from opaque to transparent, or when to "open and close" the window. To operate the window, an electrode can be used to change the orientation of liquid crystal molecules in the PDLC layer, akin to how LCD display technology works.
The controller decides when to "open the window" based on a number of inputs which can range from a photo application starting up to reveal a camera, or an unlock screen that would uncover a fingerprint reader.
Illustration of window controller operation.
Perhaps most interesting is the patent's suggestion to dispose the window behind a transparent OLED display, thereby allowing components to be situated not merely in a device's bezels or backplate, but under the screen itself. As seen in the illustration below, this implementation would be particularly useful in unlocking the device with a fingerprint reader or face-recognizing camera.
Camera for facial recognition security behind translucent OLED and PDLC window.
While the invention is enticing, it is unclear if and when Apple plans to integrate such a solution into a consumer product. The move to an aluminum uni-body shell with the iPhone 5 limits the utility of the patent moving forward, at least when compared to the previous generation handset's "glass sandwich" design, a prime candidate for the "hidden window" tech.
Apple filed the patent application in April 2011, with Felix Jose Alvarez Rivera, Richard Hung Minh Dinh and Scott A Myers credited as its inventors.