From Monochrome Screens， A Detailed Explanation of the Evolution of Mobile Phone Screens

The evolution of mobile phone screens is an epic of technological advancement, constantly pushing the boundaries of display quality, interactive experience, and form factor innovation. From the initial monochrome pixels to today's flexible foldable screens, each iteration has profoundly changed the way users interact with their phones. Below is a complete analysis of the evolutionary process, starting with monochrome screens:

1. The Era of Enlightenment: The Initial Exploration of Monochrome Screens (1980s-Late 1990s)

The core need during this stage was "basic information display." The screen served only as an auxiliary tool. While technology was limited, it pioneered mobile phone visualization.

Core Technology:

Monochrome LCD screens, primarily based on STN (Super Twisted Nematic Liquid Crystal) technology, could not emit light themselves, relying on ambient light or simple backlighting. Display was achieved by the CPU controlling whether pixels were "black" or "not black."

Key Features:

Extremely Simple Display Content: Only supported basic information such as English letters and numbers, simple text (e.g., phonebook, SMS), time, signal strength, etc. No color representation, and extremely low resolution (typically tens of pixels).

Rough Design: Early models were mostly narrow and elongated, later transitioning to square shapes. Screen sizes were small (mostly 1-2 inches), resulting in severe image retention and extremely narrow viewing angles.

Representative Models and Milestones:

In 1987, the Motorola 3200 ("Big Brother") entered China, featuring a dual-line monochrome screen. It was the first mobile phone with a screen to open up the Chinese mobile communications market, becoming a status symbol.

After 1995, screen functionality was upgraded, displaying more information such as operator names. Representative models included the Nokia 6150, Motorola L2000, and Ericsson R250. This type of screen remained in use until the early 21st century.

In 2000, the Samsung A288 was released. As the world's first dual-display phone, it pioneered the "main screen + secondary screen" design concept, laying the groundwork for later foldable screens.

2. The Awakening of Color: Technological Divergence in the Era of Color Screens (2000s-Early 2010s)

As mobile phone functions shifted from "communication tools" to "multimedia devices," color display became a core requirement. LCD technology dominated the market and branched out into several sub-sectors, while the prototype of touchscreens emerged.

(1) Early Color Screen Technology: The Transition from STN to CSTN

Technical Principle: CSTN (Color STN) adds a color filter to monochrome STN, splitting each pixel into red, green, and blue sub-pixels to achieve color display.

Limitations: Low color saturation, slow response speed, and high power consumption; it could only meet the basic requirement of "having color" and was quickly replaced by more advanced technologies.

(2) Mainstream Color Screen Technology: The Dominance of TFT-LCD

Core Technology: TFT (Thin Film Transistor) is a mature upgrade solution for LCD. By controlling each pixel with an independent transistor, it solved the image retention and response speed problems of STN.

Core advantages: High color reproduction, excellent contrast, mature technology, high production volume, and low cost, making it the standard for mainstream mobile phones from 2000 to 2010, covering mid-range, high-end, and low-end models.

Representative applications: Most Nokia models before the N97 (except for the N85 and N86), and early flagship models from brands like Sony Ericsson and Samsung all used TFT screens.

(3) Optimized branches of TFT: IPS/SLCD/ASV

IPS technology: "Advanced version of TFT," featuring ultra-wide viewing angles, low power consumption, no water ripples on touch, and outstanding color transparency. All Apple models before the iPhone X used IPS screens, establishing its high-end status.

SLCD technology: Dedicated display for splicing, widely used in HTC models. It combines the high color reproduction advantages of LCD with a long lifespan and a warmer color tone. Later, upgraded versions such as SLCD 5 were developed.

ASV Technology: A Sharp patented technology that improves viewing angles by reducing the spacing between liquid crystal particles and increasing the aperture. It was widely used in Sharp's self-developed products and early models such as the Meizu MX and Xiaomi 1.

(4) The Interaction Revolution: The Rise of the Touchscreen

In 1994, the IBM Simon phone first used a monochrome resistive screen, requiring a stylus for operation. Although the feel was rough, it pioneered "touch interaction."

In 2007, the first iPhone was released, featuring a capacitive touchscreen that supported multi-touch, completely replacing the stylus and upgrading the screen from a "display tool" to the "interaction core," reshaping the logic of mobile phone operation.

3. The Leap in Display Technology: OLED's Complete Takeover (Mid-2010s - Present)

As users' demands for "thin, light, high-definition, and low-power consumption" increased, self-emissive OLED technology gradually replaced LCD, becoming the mainstream mobile phone screen, while form factor innovation entered a period of explosive growth.

(1) Technological Advantages and Evolution of OLED

Core Characteristics: Contains its own diodes, eliminating the need for a backlight layer; self-emissive; possesses unparalleled advantages over LCD, including ultra-thinness, high contrast (pure blacks), wide viewing angles, high response speed, and flexibility.

Technological Iterations:

Early AMOLED: Pioneered by Samsung, offering vibrant colors but noticeable pixel arrangement defects and a grainy appearance. The first device to feature it was the Nokia N85.

Super AMOLED: Samsung optimized the pixel arrangement to a diamond pattern, reducing graininess and jagged edges, significantly improving visual effects. The representative model is the Samsung S8.

Dynamic AMOLED: Supports the HDR10+ standard, offering richer details in dark areas, with a maximum brightness of 1215 NT, clearly visible even in strong outdoor light. The representative model is the Samsung S10.

(2) Form Factor Innovation: From Narrow Bezels to Notch Displays

Narrow Bezels/Borderless: Inspired by the iPhone 5's "increased screen-to-body ratio while maintaining a slim design," manufacturers extended the screen ratio and reduced the mid-frame, introducing narrow bezels and borderless designs to maximize the display area.

Curved Screen: Leveraging the flexibility of OLED, Samsung launched its first single-sided curved screen phone, the N9150, which was later optimized into a dual-sided curved screen Galaxy S6 Edge, achieving a smooth transition effect while adding practical functions such as always-on display, balancing aesthetics and practicality.

Notch Screen: To resolve space conflicts with components such as the front-facing camera, notch screens, teardrop notches, and punch-hole screens emerged, balancing functionality and aesthetics while maintaining a high screen-to-body ratio.

(3) Experience Upgrade: High Refresh Rate and High Resolution

Refresh Rate Breakthrough: Upgrading from the traditional 60Hz to 90Hz, 120Hz, and even 144Hz, models such as the ROG Phone 2 and OnePlus 7 Pro pioneered the use of high refresh rate screens, significantly improving scrolling smoothness and game responsiveness.

Resolution Improvement: Evolving from 720P and 1080P to 2K and 4K, combined with HDR technology, color performance and detail reproduction reached new heights, becoming a standard feature of high-end flagship phones.

4. Future Form Factor: The Flexible Revolution of Foldable Screens (2018-Present)

The maturity of flexible OLED technology has given rise to foldable screens, resolving the contradiction between "large-screen display" and "portability," becoming the latest direction in the evolution of mobile phone screens.

Development Milestones:

In 2018, Royole released the FlexPai, the world's first foldable phone, using a 7.8-inch flexible OLED screen that supports bending at any angle from 0-180°.

2019 was dubbed the "Year Zero of Foldable Screens," with the release of the Samsung Galaxy Fold (inward-folding solution) and the Huawei Mate X (outward-folding solution), marking the entry of foldable screens into the mass production stage. Although initial issues such as creases and weight existed, it initiated industry exploration.

Since 2020, technology has continued to optimize: the Huawei Mate X2 adopted a dual-spinning waterdrop hinge, the vivo X Fold2 achieved a near-crease-free effect, and the Huawei Mate Xs2 reduced its weight to 255g, increasing its folding lifespan to hundreds of thousands of times. Meanwhile, the system ecosystem has gradually adapted to large-screen interaction.

Market Landscape: China has become the world's largest foldable screen market. Huawei and Samsung dominate the high-end business market, while brands such as Honor, Xiaomi, OPPO, and vivo attract users with their lightweight, cost-effective, and youthful designs. Global shipments reached 22.7 million units in 2023 and are projected to increase to 55 million units by 2025.

Evolutionary Logic Summary: The evolution of mobile phone screens has always revolved around the core of "user experience": from "able to display" (monochrome screen) to "able to display color" (color screen), then to "good display" (OLED high-definition), and finally to "clever display" (foldable screen flexible form). In terms of technology, breakthroughs in materials (from LCD to OLED flexible materials), processes (from transistor control to thin-film encapsulation), and interactions (from buttons to touch and then to foldable interaction) have propelled the screen from an "auxiliary component" to a core competitive advantage for mobile phones. In the future, it will continue to evolve towards "lighter, thinner, more durable, higher image quality, and more intelligent (such as under-display cameras and holographic displays)".