Vision is the most important sensory channel for human beings, contributing more than 80% of all sensory information input. As the core carrier of visual information transmission, display technology has continuously pushed boundaries since its inception. From simple light-and-shadow imaging to today’s ultra-high-definition flexible displays, it has gone through an extraordinary journey of innovation.
From the blurry images of black-and-white CRT tubes to the delicate picture quality of 4K/8K UHD screens; from bulky and heavy units to ultra-thin, foldable flexible panels, display technology has achieved leapfrog upgrades in thickness, resolution and overall performance.
Each technological iteration has not only completely changed the way humans view the world, but also deeply empowered many fields including entertainment, office, education, medical care and industrial displays. It continues to meet core demands such as simultaneous viewing by multiple people, long-term stable operation and multi-scenario adaptability, making itself an indispensable part of modern technological civilization.
I. CRT (Cathode Ray Tube): The Dawn of Display Technology
At the core of a CRT monitor lies a vacuum glass tube, with an electron gun at one end and a phosphor coating on the other. The electron gun emits high-speed electron beams, which scan the screen regularly under the magnetic field of deflection coils and strike the phosphors to produce light and form images. Color CRTs adopt three separate electron guns for red, green, and blue, which target corresponding color phosphor dots and generate full-color images based on the principle of three-primary color mixing.
This technology boasts remarkable advantages: stable phosphor luminescence, wide color gamut coverage, and microsecond-level electron beam scanning, ensuring no motion blur in dynamic images, making it the mainstream choice in early display applications. However, limited by its structural design, larger screens result in significantly heavier and bulkier units — a 32-inch model can weigh over 50 kg. Additionally, high-voltage driving leads to relatively high power consumption and certain electromagnetic radiation. Furthermore, its resolution can hardly exceed 1080P, gradually failing to meet the subsequent demand for high-definition display.
II. Rear-Projection Technology: A Transitional Attempt at Reducing Bulk
Rear-projection televisions separated image generation from image display. They used CRT tubes, LCD panels, or DMD chips as image sources, which were enlarged through an optical lens system and projected onto the back of a translucent screen. Viewers watched from the front, effectively reducing the thickness of the television set.
Among these technologies, CRT rear-projection TVs inherited the advantage of accurate color reproduction, but suffered from low brightness, narrow viewing angles, relatively large size, and the need for regular focus adjustment. LCD rear-projection TVs improved brightness and resolution, yet faced issues such as the screen-door effect and insufficient color saturation. DLP rear-projection TVs, by controlling light through micromirror switching, offered high contrast, fast response times, and no screen-door effect, making them the most mature form of rear-projection technology.
However, rear-projection televisions as a whole still remained bulky, with brightness and contrast far inferior to flat-panel displays. Their light sources had limited lamp lifespans and high replacement costs, while image distortion could occur when viewed from the side. Ultimately, they were replaced by a new generation of display technologies.
DLP Unit Imaging Principle
III. PDP (PLASMA DISPLAY PANEL): AN EARLY EXPLORATION OF SELF-EMISSIVE DISPLAY TECHNOLOGY
Plasma display panels contained millions of tiny discharge cells filled with inert gases such as neon and xenon. When voltage was applied across the electrodes, the gas discharge generated ultraviolet light, which excited red, green, and blue phosphors coated on the inner walls to produce images.
Its core advantages were highly notable: phosphors offered high luminous efficiency, a wide color gamut, and vivid color reproduction. Since each pixel emitted light independently, black levels were far superior to those of contemporary LCDs, with native contrast ratios exceeding 10,000:1. Response times were only a few microseconds, eliminating motion blur in dynamic scenes, and viewing angles were unrestricted, allowing distortion-free viewing from virtually any position.
However, plasma technology also had significant drawbacks. Prolonged display of static images could cause irreversible phosphor degradation, resulting in permanent image retention or burn-in. At the same time, power consumption was higher than that of contemporary LCDs, and the overall lifespan was shorter, leading to its gradual withdrawal from the market.
Vision is the most important sensory channel for human beings, contributing more than 80% of all sensory information input. As the core carrier of visual information transmission, display technology has continuously pushed boundaries since its inception. From simple light-and-shadow imaging to today’s ultra-high-definition flexible displays, it has gone through an extraordinary journey of innovation.
From the blurry images of black-and-white CRT tubes to the delicate picture quality of 4K/8K UHD screens; from bulky and heavy units to ultra-thin, foldable flexible panels, display technology has achieved leapfrog upgrades in thickness, resolution and overall performance.
Each technological iteration has not only completely changed the way humans view the world, but also deeply empowered many fields including entertainment, office, education, medical care and industrial displays. It continues to meet core demands such as simultaneous viewing by multiple people, long-term stable operation and multi-scenario adaptability, making itself an indispensable part of modern technological civilization.
I. CRT (Cathode Ray Tube): The Dawn of Display Technology
At the core of a CRT monitor lies a vacuum glass tube, with an electron gun at one end and a phosphor coating on the other. The electron gun emits high-speed electron beams, which scan the screen regularly under the magnetic field of deflection coils and strike the phosphors to produce light and form images. Color CRTs adopt three separate electron guns for red, green, and blue, which target corresponding color phosphor dots and generate full-color images based on the principle of three-primary color mixing.
This technology boasts remarkable advantages: stable phosphor luminescence, wide color gamut coverage, and microsecond-level electron beam scanning, ensuring no motion blur in dynamic images, making it the mainstream choice in early display applications. However, limited by its structural design, larger screens result in significantly heavier and bulkier units — a 32-inch model can weigh over 50 kg. Additionally, high-voltage driving leads to relatively high power consumption and certain electromagnetic radiation. Furthermore, its resolution can hardly exceed 1080P, gradually failing to meet the subsequent demand for high-definition display.
II. Rear-Projection Technology: A Transitional Attempt at Reducing Bulk
Rear-projection televisions separated image generation from image display. They used CRT tubes, LCD panels, or DMD chips as image sources, which were enlarged through an optical lens system and projected onto the back of a translucent screen. Viewers watched from the front, effectively reducing the thickness of the television set.
Among these technologies, CRT rear-projection TVs inherited the advantage of accurate color reproduction, but suffered from low brightness, narrow viewing angles, relatively large size, and the need for regular focus adjustment. LCD rear-projection TVs improved brightness and resolution, yet faced issues such as the screen-door effect and insufficient color saturation. DLP rear-projection TVs, by controlling light through micromirror switching, offered high contrast, fast response times, and no screen-door effect, making them the most mature form of rear-projection technology.
However, rear-projection televisions as a whole still remained bulky, with brightness and contrast far inferior to flat-panel displays. Their light sources had limited lamp lifespans and high replacement costs, while image distortion could occur when viewed from the side. Ultimately, they were replaced by a new generation of display technologies.
DLP Unit Imaging Principle
III. PDP (PLASMA DISPLAY PANEL): AN EARLY EXPLORATION OF SELF-EMISSIVE DISPLAY TECHNOLOGY
Plasma display panels contained millions of tiny discharge cells filled with inert gases such as neon and xenon. When voltage was applied across the electrodes, the gas discharge generated ultraviolet light, which excited red, green, and blue phosphors coated on the inner walls to produce images.
Its core advantages were highly notable: phosphors offered high luminous efficiency, a wide color gamut, and vivid color reproduction. Since each pixel emitted light independently, black levels were far superior to those of contemporary LCDs, with native contrast ratios exceeding 10,000:1. Response times were only a few microseconds, eliminating motion blur in dynamic scenes, and viewing angles were unrestricted, allowing distortion-free viewing from virtually any position.
However, plasma technology also had significant drawbacks. Prolonged display of static images could cause irreversible phosphor degradation, resulting in permanent image retention or burn-in. At the same time, power consumption was higher than that of contemporary LCDs, and the overall lifespan was shorter, leading to its gradual withdrawal from the market.
