Displays and light bulbs typically emit light in more wavelengths and in more directions than the user sees. Apple is looking to minimize unseen, unused energy to produce more efficient displays that save power. "Electronic device with light-recycling emissive display" is a newly exposed Apple patent application that shows Apple exploring the inclusion of such efficient screens in devices. Apple took some work to make sure the application covered every conceivable device, from phones, head-mounted displays, and even watches.
Apple is also casting a wide net, even listing the types of materials it describes as possible for the devices it describes, "polymers, metals, glass, crystalline materials such as sapphire, ceramics, fabrics, fibers, fiber composites, natural materials such as wood and cotton. materials, other materials and/or combinations of these materials". However, in a technical patent application that is both very broad and sometimes very specific, the central purpose is always the same. An "emissive display" produces its own light, and Apple wants to make the process more power-efficient.
The OLED screens used in iPhones and iPads are emissive displays. On the contrary, it is called a transmissive display, that is, the screen itself does not produce light. For example, the displays on early iPods were transmissive because they were independently backlit LCD panels. Transmissive displays require what Apple calls "photoresist structures" or "crosstalk-preventing structures" that allow the display to maintain a clear appearance.
Apple said that without the light blocking structure, light could reach the red pixel R and could therefore create mixed light between the red pixel R and the green pixel G, reducing the contrast of the display. Therefore, a certain amount of light energy has been deliberately blocked. Apple is researching how to reuse this energy. In order to improve the light emission efficiency of the display screen, a light recycling structure may be included. "
The patent application details a number of ways in which polarized and unpolarized light can be used and then re-routed to or from the display. In each of the cases described, though, the benefits are twofold. First, users can see clear, sharp images on their headphones or any other display. But secondly, Apple can display images with lower overall power consumption.
Editor in charge AJX