Digital entertainment right before your eyes—the evolution of smart glasses
The metaverse craze is coming, and the development of digital interactive entertainment is becoming more and more diverse! I believe everyone is familiar with VR glasses, but it is still difficult for everyone to get one. On the contrary, AR technology is developing more and more vigorously!
For example, a museum combines AR glasses with hand-held devices for interactive integration, allowing the dinosaur specimens on display to come alive in front of your eyes; or go to the two halls to watch a drama, and the exclusive AR subtitle experience allows audiences from different countries to enjoy it instantly with an in-depth tour.
How has this digital entertainment that is so close to our eyes—smart glasses—evolved? What technical barriers need to be overcome?
First of all, you need to understand what VR, AR and even more advanced MR and XR are? Where are these differences?
Can’t tell the difference between AR, VR, MR and XR? In fact, the AR, VR and MR that everyone has heard of so far all belong to the big concept of XR (Extended Reality). As long as this device or software allows you to experience information other than reality, and even interact with it. Interactive feedback belongs to XR!
In recent years, VR (Virtual Reality), which has become popular due to Meta CEO Zuckerberg’s vow to enter the metaverse, emphasizes immersive experience. As long as you wear VR glasses, you can be at home or going to a VR virtual reality amusement park. All of them allow you to experience interesting experiences such as fighting Godzilla or exploring a virtual haunted house. However, wearing VR glasses requires complete sensory occlusion, as well as the high price and computer computing, even the weight and discomfort when wearing, and the space requirements for operation… These are shortcomings that are not easy to overcome and are still waiting for the market test.
In comparison, AR (Augmented Reality) is much closer. As early as the 1990s, Akira Toriyama used the device “Combat Power Detector” in his classic work “Dragon Ball” to let us experience what AR is, and the combat effectiveness detector in the real world is right in front of you. For example, the HUD that displays speed on the glass panel of a car is a kind of projection of virtual information onto real objects. This is standard AR technology!
When talking about AR, we must mention that in 2016, the game company Niantic launched a game called Pokemon Go, which set off a global craze of catching Pokémon everywhere. This craze continues to this day, and it also reflects the AR’s real strength: combination with the real environment.
Over the years, many selfie filters or sightseeing stamp collection activities have also used AR technology to present the characteristics of virtual elements in the background of the real environment, and this only requires the smartphones you and I have to operate and see virtual characters or headwear. The entry barrier is much lower than VR, and the cost of software development is much easier than having to create a metaverse of a world.
Since AR can project virtual information into the real field, we will naturally be more greedy and want to interact with these virtual characters, even as a floating robot like the technology in Tom Cruise’s “Key Report” to use the control interface. What we need at this time is not just AR, but MR (Mixed Reality). In MR technology, there is not only the superposition of the real world and the virtual world, but also the emphasis on the interaction between virtual elements and the real environment. For example, a virtual car can detect the edge of your real table and brake, or even you can reach out and touch virtual elements. It will produce interactive or grabbing effects, and these technologies may not be easily achieved with a mobile phone.
For AR to enter MR, in addition to mobile phones, a device that can capture external information-AR glasses are also needed. In fact, the main problems that AR glasses have faced over the years are “the picture must be clear”, “the color must be saturated”, “it should not interfere too much with the real line of sight”, and it must also have characteristics such as “lightweight” and “comfortable”.
Evolutionary breakthroughs in projection technology bring new opportunities to smart glasses
The current mainstream AR glasses use two key technologies: “total reflection lens” and “micro-projection mini projector”. The “total reflection lens” on AR glasses has been precisely calculated and adjusted according to the refractive index of the eyeball, and can perfectly present the clearest image on the human retina. At the same time, the “total reflection lens” itself has excellent light transparency. It is also high, so you can still see the real world scenery outside the “total reflection lens”, allowing the clear images provided by AR glasses to overlap with the real world.
When talking about another core technology of AR glasses, “miniature projection”, we have to mention the development of the most practical and potential AR glasses – Epson projector manufacturer. Before understanding the “miniature projection” technology, we must first look back at Epson’s changes from the development of projection technology in 1989 to the present.
The projectors that Epson first produced used LCDs. The biggest difference from the screens was that each projection pixel used three LCDs. It turned out that this was because in optical principles, as long as there are three colors of blue, red and green, they can be combined. Various colors, that is, 3LCD projection technology.
Projectors using 3LCD technology must first filter the white light source of the background lamp into three-color light, then use three independent LCDs to adjust the ratio of each color for modulation, and finally combine the three-color light into an image and project it out. Such a troublesome reflection process naturally requires a lot of space, and after such refraction and filtering, the saturation and contrast of the color will always be one level lower, and may even produce an ugly screen door effect (SDE) when viewed up close, which is why the presentations projected by early projectors were often not as good as those previewed on the computer screen.
Of course, projector manufacturers have long noticed this problem, so they have also evolved from LCD to OLED (organic light-emitting diode) along with mobile phone screens, bringing a new display revolution! The main function of LCD liquid crystal is color adjustment, then the great thing about OLED is that “it emits light by itself”! Unlike traditional LCD panels, which require a light source and backplane to reflect light into the filtering stage, LED light bulbs have been developed through the efforts of many scientists, including Isamu Akasaki and Hiroshi Amano, three Japanese scientists who won the 2014 Nobel Prize. After Hiroshi Amano and Shuji Nakamura developed the last “blue LED”, they finally achieved the achievement of emitting three primary colors. Since then, screen and projection technology no longer require redundant filtering and reflection steps, so panels can become thinner and at the same time have better contrast.
The subsequent OLED technology has made the panel independent of glass and switched to a plastic bottom plate, making foldable mobile phones and curved screens like science fiction props a reality. OLED technology simplifies the entire process, and the color quality is more vivid and saturated than various original projection methods. It quickly greatly reduces the internal space of the projector and becomes a portable projector trend for camping enthusiasts.
But here comes the problem! When the projector is put on glasses, the difficulty is much higher than that of a portable projector. On the road to miniaturization, “there is only smaller, not smallest”.
Epson launched its first AR glasses, BT-100, as early as 2011, and continued to develop towards lightweight and functionality. In 2016, it launched BT-300, which uses silicon-based organic light-emitting diode Si-OLED micro-projection technology. Various manufacturers have also invested in the research and development of micro OLED projection, and I believe that more powerful AR glasses will be launched in the future.
With the continuous development and evolution of smart glasses, the world of digital interactive entertainment will become more immersive and accessible to everyone. The possibilities are endless, and the metaverse craze is just the beginning.