Apple has applied for a patent on a screen it is working on that would enable for increased privacy on portable devices such as the iPhone and iPad, Cnet reported, citing a patent application published on 3 August. Apple Insider said the patent was filed with the US Patent and Trade Office in June. 

"Displays are typically designed to display images over a relatively wide angle of view to accommodate movements in the position of a viewer relative to the display," Apple said in its application. "In some situations, such as when a user of a laptop or other device with a display is using the device in public, the wide viewing angle is undesirable as it compromises privacy." Apple called its application "Displays With Adjustable Angles-of-View." 

In the document, the company discusses using an electrically adjustable lens array that can modify backlight illumination to narrow the display's angle of view. Rather than using an attachable filter, this approach would be integrated into the display in a series of substrate layers, with a layer of liquid crystal material sandwiched between. The substrate layers then might include a colour filter and thin-film transistor. The liquid crystal layer could then be controlled using electrodes, changing portions of the filter layer to a dark or translucent state and restricting the display's angle of view.