Which Display Technologies Require Backlighting? Comparing LCD, LED, and OLED
The displays powering our phones, computers and televisions come in different types, each with their own strengths and weaknesses.
Key aspects like brightness, power usage, and thinness vary across liquid crystal display (LCD), light emitting diode (LED) and organic light emitting diode (OLED) technologies. Often overlooked difference is their dependence on backlighting.
The blog post will explore how Display Technologies like LCD, LED and OLED panels compare in terms of requiring separate backlight layers or emitting light independently.
LCD Displays: Relying on Backlights for Over Two Decades
LCD screens were the most not unusual display type for decades, determined in gadgets from desktop monitors to laptops, drugs and the past.
A liquid crystal display panel makes use of liquid crystals and polarized filters layered among two glass substrates to manipulate how many mild passes via each pixel. The modulation of light is then seen as images and video on the screen.
| Component | Purpose |
| Liquid crystals | Bonds to polarized filters, arrangement controlled by voltage at each pixel |
| Polarizing filters | Only allow light waves of specific polarization angles to pass through |
| Backlight | Provides the light source for the liquid crystals to control |
LCDs are not emissive; they cannot produce their own light. Instead, they have always required a separate backlight unit positioned behind the liquid crystal layer.
Early CCFL backlights used fluorescent tubes for an even glow across the screen. Newer LCDs incorporate LED backlights for improved brightness, color and lower power consumption compared to CCFLs.
Regardless of the specific backlight technology, LCD panels are inherently dependent on the supplemental lighting layer. Without a backlight providing luminous flux, the liquid crystals would have nothing to modulate resulting in a black screen.
LED Display Technologies: Bright Pixels But Still Requiring Backlights
LED Display Technologies take a distinct approach by making each pixel into its own micro light emitting diode. The self emissive capability allows for greater brightness, higher contrast ratios and a longer operational lifespan than LCD screens. Not all LED display types can forego the use of supplemental lighting.
Current LED TV and monitor panels fall under two structures:
- Edge lit LED Has a strip of LEDs around the screen edges that serve as a backlight for the pixel array.
- Direct lit LED Places an array of LED backlights directly behind the pixels.
Without the illuminated backlight layers, even LED screens would only be able to produce images at a very low luminance. So while the pixels themselves are emissive LEDs, full array LED displays still depend on separate backlight technologies.
Display Technologies OLED Stands Apart With Self Emissive Pixels and No Backlights:
OLED or organic light emitting diode screens represent the one display type that has truly achieved independence from supplemental backlights.
Like LED displays, each pixel in an OLED panel is its own miniature light source consisting of organic thin film layers that emit light when voltage is applied.
The OLEDs differ in that the pixels are emissive on their own without requiring any type of backlight behind them.
It allows for OLED to enable truly slim, flexible and possibly even transparent displays in the future. With deep blacks, wide color gamut’s and high contrast, OLED also produces some of the best image quality available.
As OLED TVs and monitors become more mainstream, they represent the clearest break from displays reliant on separate backlight technologies like LCD and current LED versions.
Only OLED has crossed the threshold to self-emissive pixels that glow independently without any need for supplemental lighting of any kind behind the scenes.
FAQ
Q. What display technologies require backlighting?
A. liquid-crystal displays (LCDs)
Q. Which is a monitor backlight technology?
A. Standard LCD monitors employ “cold cathode fluorescent lamps,” also known as CCFLs as backlights.
Q. Which of the following is the most common type of backlighting?
A. The type of backlight technology commonly used in modern laptop devices is LED (Light Emitting Diode).
Q. Does LCD require backlighting?
A. A backlight is an essential component in LCDs.
Q. What is backlighting on display?
A. Backlight is the light that allows an LCD screen to create an image.
Conclusion
Display Technologies LCD, edge lit LED and direct lit LED screens require backlights such as CCFLs or LED strips to function, OLED stands alone as a display that emits its own light independently at the pixel level.
The freedom from backlights is part of what gives OLED unique design possibilities compared to first generation emission display types. As OLED adoption increases, it may help drive the industry beyond inherent reliance on supplemental backlights.
