In recent years, mobile phone manufacturers have tried a variety of methods to maximize the screen-to-body ratio without increasing the size of the phone itself. The method is either to eat into the top bezel with a notch, like the notched display in iPhone X, teardrop notch in OnePlus 6T, hole-punch display in Honor View 20, or to compress or hide the camera, like the pop-up camera in OnePlus 7 Pro, the slide-up camera in Samsung Galaxy A80, the under-screen camera in Xiaomi.
Now, we will focus on the left and right bezel design of the phone in this post to discover how it influences the screen-to-body ratio.
Actually, ever since the emerging of the smartphone, the innovation of the mobile phone design appearance is the continuous reduction of the screen bezel from the top, bottom, left and right. Here we take the iPhone as an example, from the first generation iPhone 1 to the latest iPhone Xs Max, the phone’s display vision has become much wider and amazing.
In other words, by increasing the screen-to-body ratio to achieve the effect of “all sights are screen”, it is the ultimate goal of smartphone development.
The accurate screen-to-body ratio is universally recognized as data that tells you how much of the surface the screen displays when compared to the whole device. Thereinto, the surface area of the screen excludes the black edge, while the total surface area of the whole device doesn’t count the raised buttons.
In the total surface area, bezels occupy a large proportion. But many manufacturers only focus on the top and bottom bezels but ignoring the influence of the left and right bezels.
In fact, when the under-screen camera technology and COP packaging technology become popular, the last evolution to the "true fullscreen" smartphone is to reduce the left and right bezels.
The width of the top bezel of the phone (accurately the height) depends on the process of the front camera. If you are interested, please refer to the post Under-display Camera Technology Is Upcoming! Is the “True Full Screen” Good or Not?
While the width of the bottom bezel of the mobile phone is affected by the screen material and packaging process. If you have an interest, please refer to the post To Get Higher Screen-to-body Ratio, All Depend on It! What is the COP Package That is More Important Than Notched Display?. This post, it covers the analysis of COG (Chip On Glass), COF (Chip On Flex) and COP (Cyclo Olefin Polymer) packaging technology.
As seen in the second picture of this post, the biggest feature of the latest iPhone X series mobile phone is to achieve the equal width design of all the bezels. The left and right bezels have been greatly narrower than that of the first generation iPhone.
In fact, whether it is an iPhone or an Android phone, the component elements of the screen bezel are the same, from inside to outside are "screen panel + display black edge + screen bezel + buffer layer + body bezel + raised button " respectively.
In order to improve the touch feeling, most of the middle bezel of the mobile phone will also be processed in the curvy edge, which makes the actual frame of the mobile phone thicker. Even in the new mobile phones that were launched in 2019, the total width was rarely less than 6mm when adding the left and right bezels.
The reason why there is a "buffer layer" in the phone frame is to reduce the probability of the broken screen when the phone is dropped. The buffer layers are different in terms of the material, thickness and filling method in mobile phones of different periods and models. The most representative one is the "suspension dispensing technology" that Meizu high-end mobile phone once featured. It is a kind of custom glue to make the screen and aluminum body together. The glue layer can be fixed position of the screen, at the same time, it has the buffering capacity. When the phone drops or dramatic impacts, the buffer layer glue can decrease the broken screen.
In short, the left and right bezels of the phone screen will become the main target of the next generation of flagship phones. At present, we already have better solutions like the curved screen and waterfall screen, especially the latter, it has achieved a near-borderless visual effect.