现实世界很棒，但是增强现实（AR）技术可以使其变得更好 - 更有趣，信息丰富，富有成效和教育。虽然尚未适合消费者的可穿戴AR眼镜，但好消息是，所有基于智能手机的AR的应用程序和工具为轻松迁移到AR眼镜上的下一代应用程序铺平了道路。
在某种程度上，基于智能手机的AR已充当概念证明。硬件的下一步将是舒适，高性能，负担得起的AR眼镜。但是，创建此类设备需要克服一些技术挑战。
AR Everywhere…
Since the meteoric rise ofPokemon Go in 2016，AR应用程序无处不在。实际上，诸如Facebook，Snapchat，Instagram等公司之类的公司都跳上了潮流。AR开发环境如苹果的Arkit和Google的Arcore极大地帮助了iPhone和Android设备上的AR应用程序扩散(Fig. 1)。现在负担得起的，即使不是免费的，例如Blippar，Zappar和Aurasma等AR内容创建工具使应用程序开发人员，小型和大型企业甚至非营利组织更容易进入AR。
1.将零售信息添加到视图中只是增强现实应用程序的一个示例。
游戏可能已经为AR提供了最初的动力，但是现在各种新的AR应用程序正在进入诸如教育，市场和广告，建筑和工程，博物馆以及其他地区等多样化的行业。像宜家这样的零售商提供AR应用程序，使潜在的买家看到家具在家中的外观。Airbnb展示了一个AR应用程序，该应用程序在租房者到达时为租房者提供了丰富的导览游。
Educational AR apps create an immersive learning environment. Instead of reading or watching a video about volcanoes, imagine middle schoolers experiencing a volcanic eruption that’s happening, virtually, on top of their desk.
The British Museum is testing an AR smartphone app that would replace recorded descriptions or wall-mounted note cards describing a work of art with an informative reenactment of how the piece was created. Architectural or engineering firms are combining physical models with AR so that clients can experience a building from the inside out while presenting explanatory or promotional information. The results are much more engaging, to say the least. These examples point to a brave new world for AR.
Next-Gen Wearables
While apps on smartphones may have demonstrated the viability and vast potential of AR, next-generation glasses designed specifically for AR apps will provide a much more powerful and immersive experience. Unlike smartphones, where the AR experience is bounded by the borders of the display screen on the phone, the images and graphics displayed by AR glasses will seem to float right in front of the viewer’s field of vision as if they were indeed real and a part of the scene.
Several different types of applications could be a great fit for AR glasses. Gaming, of course, is one. Imagine small battleships cruising around the furniture in your living room and planes attacking from your ceiling fan. In mechanical and industrial engineering, the ability to see and manipulate 3D objects will be very useful. Cyclists, skiers or motocross riders could benefit from AR glasses embedded in their helmets that display critical information like speed, heart rate, location on the course, remaining fuel, and others. In inventory management or warehousing applications, AR glasses could either guide personnel to a hard-to-find storage bin or give instantaneous confirmation that the right item has been pulled from inventory.
For these and other applications to be successful, the AR glasses must be comfortable to wear and have a balance of acceptable battery life and high performance. A critical component of how such glasses will be judged is the display subsystem. The goal is to trick the brain into thinking that what it’s seeing is part of the real world, and to reach that level of performance will require a well-designed AR display.
Design Considerations
设计人员在设计最佳AR眼镜时可以遵循几种不同的方法。每种显示技术都会有自己的优势和劣势，但是在评估AR显示技术时，任何AR眼镜设计师都有某些操作特征，包括：
Low power:For a set of AR glasses to be small and lightweight, the display subsystem must be low power. A key determinant of an AR display’s power consumption is its optical efficiency—how much light makes it into the eye from the illumination source. A design that’s not optically efficient would have sacrificed either a small, light form factor to accommodate a larger battery, or the brightness of the display would have to be decreased because of limited battery capacity.
An optically efficient display gives developers more flexibility to optimize their designs to the requirements specific to the applications that will run on the glasses. For example, outdoor sports applications such as biking may require glasses optimized for high brightness, while glasses deployed in a warehouse inventory-management application may not require as high a brightness level and could instead optimize for longer battery life.
亮度：AR显示器的亮度是用户体验的关键决定因素。如果亮度有限，则显示可能无法在显示内容和背景环境之间产生足够的差异(Fig. 2)。此外，如果将眼镜在户外使用，则显示器的输出必须非常明亮，以使内容清晰可见。
2.明亮的AR显示（右）是用户体验的关键决定因素。如果亮度有限（左），则显示可能无法在显示内容和背景环境之间产生足够的差异。
Contrast:Contrast is a measure of the difference in a display’s blackest blacks and whitest whites(Fig. 3)。高对比度将内容非常rich and immersive. In addition, the ability for a pixel to be truly black is critical in AR glasses, because black pixels will be transparent to the wearer. When these pixels aren’t truly black, but rather a shade of gray, the wearer will see an unrealistic and distracting gray background outlining the glasses’ display area.
3. A high contrast ratio (right) makes the content richer and immersive compared to a low-contrast (left) presentation.
高速/低潜伏期：A high-frame-rate, low-latency display is particularly essential in AR applications involving head movement. In such applications, latency in the display can result in augmented content not aligning properly with objects in the real world.
结论
下一代AR glasses将使AR应用程序更接近其全部潜力。AR眼镜不会像智能手机屏幕那样以AR应用程序的现实方式进行拳击，而是将应用程序及其现实成为用户现实的一部分。到达那里将需要周到地考虑涉及眼镜显示子系统的设计问题。
