In the world of LCD screens, do you think the only thing that lights up the picture is that thin layer of glass? No. The true essence lies behind the scenes that you cannot see.
We are well aware that behind every stunning LCD screen lies a sophisticated optical revolution. The backlight module of the LCD screen is not just a supporting role for "lighting up" - it has to transform point light sources into uniform, bright, and vivid surface light, making the LCD screen truly come alive.
Especially in today's era, with the surge in customized demands, the optical performance of the backlight has become the decisive factor for differentiating screens.
At the core of all this lies a set of intricately coordinated optical films. They are like the "nerve pathways" of the backlight, silently regulating the direction, efficiency and uniformity of each ray of light, ultimately defining all the brilliance you see before your eyes.
Today, let's set aside the complex technical jargon and, from the perspective of solving practical problems, provide a straightforward explanation of the optical technology in the backlight module. This will help you truly understand the "fundamentals" for choosing and optimizing the display.
I. The Dual Missions of Backlighting
Liquid crystal by itself does not emit light; it relies entirely on the light source behind it to "shine". This light source system is called the backlight module. The backlight module has two crucial functions: converting point light sources into uniform surface light sources, and precisely controlling the brightness, uniformity and color performance of the light. Therefore, the backlight module (BackLight Unit) as the core component of a liquid crystal display (LCD), its optical performance directly affects the display effect.
Currently in the market, the backlight modules are mainly divided into two camps: the side-entry type (ELED) and the direct-down type (DLED).
The side-entry design achieves this by placing LED lights along the edges of the screen and using a light guide plate to direct the light throughout the entire screen. This results in an astonishingly thin design - this is why our mobile phones and ultra-thin displays can be so slim.
The flush-mounted type evenly distributes the LED lights on the back of the screen, enabling higher brightness, more uniform light distribution, and the feature of local dimming (which allows for individual area lighting control).