Birdbath is another solution for AR optics.
It contains a spherical mirror/combiner (part-mirror) and a beam splitter. The method works like a birdbath in which it projects light from the OLED into the beam splitter, at a 45-degree angle with the OLED light source plane. Lenovo Mirage AR and ODG R9 were two examples adopting this method, but it has two major downsides being light loss and double image. Curved mirror (adopted by DreamWorld and Leap Motion) is the cheapest see-through display technology. It is based on semi-reflective curved mirrors placed in front of the eye. The major advantage was the low cost because it works with LCD, but suffers from a high degree of distortion, low image resolution and less comfort.
Waveguide and micro-LED solutions are at the early stage; it is very difficult for this solution to be mass produced at a low cost, but companies such as Glo, VueReal, BOE, and AUO are investing heavily in micro-LED technology. With the advancement of mirco-LED technology, we expect the solution will be adopted by most of the AR makers in the future. For AR glasses, Meta has Project Nazare, its first AR glasses that allow augmented reality overlays on the real world.
AR requires integration of hologram displays, projectors, batteries, radios, custom silicon, cameras, speakers and sensors to map the world into glasses that are 5mm thick. It also introduced its Ray Ban Stories—which allows taking pictures or phone calls, listening to music, and watching videos—at US$299.
Meta also has a Project Cambria for new high-end glasses. With Project Cambria, Meta would integrate “high-resolution coloured mixed-reality pass-through” glasses, which combine an array of sensors with reconstruction algorithms to represent the physical world in the headset, with a sense of depth and perspective. The representation on the display with these innovations is finally getting closer to representing what the eyes see in the physical world. For optics, the company is developing pancake optics by folding light to achieve a slimmer profile than current lenses.
Vuzix, an AR headset company founded in 1997, recently unveiled its Vuzix Shield which contains battery, computer, cameras and display projector in the temples of the glasses but can be worn all day.