Understanding Backlight Types: Types and Differences
What is Backlighting?
Backlighting in the context of display technology refers to the method of illuminating the pixels on a screen. The quality of a display’s backlight can significantly influence aspects such as color accuracy, contrast, and overall image quality. There are several types of backlighting technologies used in modern displays, each with its unique benefits and drawbacks.
Types of Backlighting
CCFL (Cold Cathode Fluorescent Lamp)
CCFL is an older form of backlighting technology that was widely used in early LCD displays. It involves a series of cold cathode fluorescent lamps placed behind the screen to illuminate the pixels. CCFL backlights are relatively inexpensive to produce but consume more energy and offer less color control compared to more modern backlighting technologies.
E-LED
In Edge LED backlighting, LED lights are placed around the edges of the screen. Light is then directed towards the center of the display. This method allows for thinner and lighter displays compared to CCFL backlighting. However, it might result in less even lighting across the screen, especially in larger displays.
Why advertising screens usually use E-LED backlights?
E-LED backlighting is a great choice when power efficiency and sleek design are important considerations. By placing LEDs at the edge of the screen and dispersing light across the display through a light guide plate, E-LED technology allows for thinner, more lightweight displays. This makes E-LED a popular choice for portable devices and for any setting where space is at a premium. In addition, E-LEDs are often more energy-efficient than their D-LED counterparts, but this may come at the cost of less optimal contrast levels and black depth, as they lack the local dimming capability of D-LEDs.
D-LED
Direct LED backlighting involves placing LEDs directly behind the screen in a grid-like pattern. This setup allows for better control over light distribution, resulting in more uniform brightness across the screen. Direct LED backlighting can also use a technology called local dimming, where individual LED areas can be dimmed or brightened independently, improving the contrast ratio.
Why Interactive Whiteboard usually use D-LED backlights?
When high image quality is the top priority, D-LED backlighting can be an excellent choice. The ability of D-LEDs to independently control the illumination of different sections of the screen via local dimming can create superior contrast and deeper blacks. This results in a more vivid and dynamic image, making D-LED a favorite choice for high-definition content, gaming, and other applications where visual quality is paramount. However, it’s important to note that D-LED backlighting can consume more power and often results in a thicker display compared to E-LED technology.
Full-Array Local Dimming (FALD)
FALD is a form of Direct LED backlighting where a large number of LEDs are placed behind the screen and can be controlled individually or in groups. This technology allows for precise control over brightness and contrast on different parts of the screen, significantly improving image quality. However, FALD is typically found only in high-end displays due to its higher production cost.
