What is a flexible screen? and its application ?

What is flexible screen

Flexible Display is a new type of display technology that uses flexible substrate materials and thin-film electronics to make the display highly flexible and malleable. Compared with the traditional rigid display, the flexible screen can achieve bending, curling, folding and other deformation, which brings new possibilities for the design and application of electronic devices.

Folding screen basics

Planar, curved and flexible screens work in much the same way, using millions of color spots (pixels) to form the image seen on the screen. And different pixel composition, derived from a variety of displays, including LCD, OLED, and more recently micro-LED and mini-LED. All of these pixels are located on a layer of material called the substrate. For many years, the substrate was a thin piece of glass - it is hard and brittle .
As we all know, glass can't bend, but plastic can. The characteristics of plastic make it the most suitable base material for the foldable screen, which not only enables the base to fold, but also improves the fall resistance of the screen, and also makes the screen thinner.
As technology has improved, display manufacturers have found ways to increase the amount of bend they can safely embed in the screen.
Crucially, they also solve the durability problem, allowing the screen to bend thousands of times without breaking. Eventually, this path led us to today's folding screen, which can be folded almost like a piece of paper.as technology has improved, display manufacturers have found ways to increase the curvature of the screen. Most importantly, they also solve the problem of durability, allowing the screen to bend thousands of times without breaking.

How the folding curved screen works

At present, the mainstream flexible folding screen on the market is an OLED flexible screen which is mainly composed of a base, an anode, a conductive layer, a luminous layer and a cathode.

OLED screens don't have backlights like LCDS do - instead, pixels glow when powered on. Because of this, OLeds can be about 30% thinner and lighter than LCDS. Coupled with other advantages over LCD, OLED is the first choice for flexible screens, but flexible LCD displays do exist.
Oleds are stacked into several ultra-thin layers on a glass or plastic substrate, in which multiple layers of organic compounds are sandwiched between two electrodes (cathode and anode). When a voltage is applied to the electrode, the electrons from the cathode and the holes (positive charges) from the anode attract each other and meet in the light-emitting layer. When an electron is combined with a positive hole, the OLED emits light, releasing energy in the form of photons.
To put it simply, folding is that components and structure of the screen can be folded, and the previous screen design is not workable, especially the glass that can not be bent at will as the screen base, so it must be redesigned.

To better understand what a foldable flexible OLED display can do, can visualize the display as a very thin (and possibly not very tasty) layer cake. each layer of this high-tech cake serves a specific purpose. These layers are laminated in a very thin package, just a fraction of a millimeter thick. Let's take a look at them.
Substrate layer - also known as the board, this is the bottom layer of the screen, which supports all the other layers. On flexible AMOLED displays, the substrate is made of plastic or, less commonly, metal. Today, most flexible screen devices use a substrate made of a polymeric plastic called polyimide (PI). In addition to being flexible and insulating, polyimides have high mechanical strength and thermal stability.
TFT layer - The TFT (thin film transistor) layer is applied on top of the flexible substrate and controls the power transmission of each pixel. Think of it as the "grid" that connects all the pixels in your display. On OLED screens, unlike LCDS, each pixel can be controlled individually, resulting in high contrast and lower power consumption.
The OLED layer - the light-emitting layer, consists of a single pixel, each containing red, green and blue sub-pixels. By varying the amount of power received by its sub-pixels, each pixel can achieve a specific color and brightness. In turn, the pixels combine to form the image we see on the display. The OLED layer consists of several sub-layers, including a cathode, an anode, and a layer of organic light-emitting material sandwiched between them.
Covering layer - also known as encapsulation layer, this is the layer that seals and protects the other layers. It is also the layer that the user touches when interacting with the folding screen. In terms of materials, the cheaper option is polyimide (the same as the substrate), and recently, we've seen manufacturers adopt ultra-thin glass (UTG). UTG is tougher than plastic and feels more like regular glass, while still bending.

Advantages and disadvantages of flexible screens

Advantages

Compared with traditional rigid screen, flexible screen has good flexibility, thin volume, low power consumption and kneading resistance. Flexible OLED screen can self-light, through self-light can achieve excellent image quality, natural color and no harm of blue light; The screen can be used flexibly, can be bent, folded


Disadvantages

When flexible AMOLED screen is applied on folding screen mobile phone, it needs to have good plasticity and ductility. The test is: after repeated stretching and compression, whether the screen can maintain no crease and no damage; Whether the circuit board and components inside the mobile phone can withstand folding and bending.

Flexible screen application field

Flexible screens show broad application prospects in various fields:

Flexible screens show broad application prospects in various fields:
1. Smart phone: Flexible screen can bring more innovative design for smart phone, achieve curved screen, waterfall screen, folding screen and other forms, improve user experience and product differentiation.
2. Wearable devices: Flexible screens are suitable for production on wearable devices such as watches, smart glasses and health monitors, which combine the characteristics of thin and portable, expanding the development space of wearable technology.
3. E-book reader: The flexible screen can simulate the texture of paper, reduce glare and eye strain, and make the e-book reader closer to the traditional book reading experience.
4. Car display: Flexible screen can be applied to car dashboard, center control screen and other positions to achieve more flexible display forms and information display, improve driving safety and comfort.
5. Tablet computer: Flexible screen can make tablet computer more thin, portable, and support a variety of deformation methods, enhance the user's enjoyment of the product.
6. Advertising display: Flexible screen can be made into a variety of curved, curly forms, for outdoor advertising, shopping mall display and other occasions, with better visual appeal and display effect.