Mini-LED is a backlighting scheme used in panels based on LED-backlit LCD technology that involves using small-sized light-emitting diodes to illuminate LCD panels and improve local dimming capabilities and increase the contrast ratio.
The Pros: Advantages and Applications of Mini-LED Display
Has the Advantages of the Overall LED-Backlit LCD Technology
Remember that LCDs are transmissive displays. They do not produce light by themselves, unlike self-emissive or photo-emissive display technologies based on light-emitting diodes such as OLED, microLED, and quantum dot displays. They need illumination or backlighting to make images visible. The preferred backlight for the majority of LCD monitors back then was cold-cathode fluorescent lamp or CCFL.
However, beginning 2010, manufacturers shifted from CCFL-backlit LCD to LED-backlit LCD. LED is more energy efficient with 20 to 30 percent lower power consumption, has a broader color gamut, enables high-speed switching, has a longer lifespan, better local dimming, and allows the production of slimmer panels.
Mini-LED display inherits the aforesaid advantages. But it provides more specific advantages over CCFL and traditional LED-based backlighting because it is fundamentally an upgrade to the overall LED-backlit LCD technology.
Improved Contrast Ratio to Match OLED Display Technology
One of the key advantages of OLED displays over IPS LCD panels is a higher contrast ratio. OLEDs produce natural and deeper blacks, while most LCDs tend to generate mere darker shades of grey. High-end LCDs such as the IPS Retina Display from Apple can produce considerable deep blacks, but they still pale in comparison to OLEDs.
Traditional LED-backlit LCDs have limited local dimming capabilities. Note that for an LCD to display black-colored images on the screen, it needs to turn off backlighting from a specific area within the panel. However, traditional LED-backlit application uses a single or multiple but sizable strips or areas of LED backlighting. Hence, although an area of LEDs has been turned off to display a black-colored image, light still bleeds out from other LEDs that remained turned on.
Mini-LED addresses this issue by increasing the local dimming capabilities of LCD panels. The concept behind using small-sized LEDs is to emulate the emissive nature of OLED. Note that OLED can produce deep blacks since it does not need backlighting, and black-colored images are actually produced by turning off individual organic light-emitting diode.
An LCD that employs mini-LED technology essentially uses LEDs about the size of 0.9 to 0.1 millimeters for backlighting. These individual LEDs can be turned on and off to enable more targeted dimming and allow the production of deeper blacks and better contrast ratio, as well as superior image quality that could rival OLED display technology.
Cost-Effective Alternative Over microLED Display Technology
Take note that mini-LED is different from microLED. The former is a backlighting scheme used in LED-backlit LCD panels, while the latter is an actual photo-emissive display technology similar to OLED displays that uses small-sized light-emitting diodes.
One key advantage of using mini-LED as a backlighting scheme for LCD is cost. It is more practical and economical to produce LCD with mini-LED than to produce OLED, microLED, and quantum dot displays. When applied in IPS LCD panels, a mini-LED LCD inherits the advantages of in-plane switching over OLEDs to include longer lifespan and durability while also demonstrating the benefits found in emissive displays.
An IPS LCD panel that uses mini-LED as backlighting can provide superior image quality that can rival OLED and microLED. It can demonstrate deeper blacks and a higher contrast ratio while also offering brightness that can exceed other emissive display technologies.
The Cons: Disadvantages and Limitations of Mini-LED Display
Can Still Be Expensive Over Traditional LED-Backlit LCD
One of the drawbacks of mini-LED is that it is still about 20 percent more expensive to manufacture than conventional LED-backlit LCD. Take note that a 45-inch to 65-inch LCD panel will need about 14000 to 20000 small-sized LEDs as its backlighting.
The technology is also relatively new. The manufacturing capacity of suppliers needs to keep up with the demand. Higher demand for micro-LED IPS LCD panels will definitely consume the production capacity of LED chip manufacturers.
Hence, because of its more expensive manufacturing cost and limited production capacity of manufacturers, the technology is best reserved for top-tier devices such as premium smartphones and tablet computers, as well as high-range laptops and television sets.
Mini-LED Also Inherits the Drawbacks of LCD Technologies
Depending on its application, mini-LED also inherits the disadvantages of the underlying display technology. Consider IPS LCD as an example. Because in-plane switching has a slower refresh rate and pixel response than OLED by default, a micro-LED IPS LCD might not be suitable for fast-paced and competitive gaming.
An IPS LCD also consumes more power than OLED and other photo-emissive display technologies because it uses backlighting. Still, it is essential to note that using micro-LED can improve the energy efficiency of LCD panels.
This backlighting scheme might be unsuitable for other LCD technologies such as twisted nematic LCD and vertical alignment LCD because it might drive up their manufacturing cost, thereby rendering them impractical to use for low-cost devices.
Summary of the Pros and Cons of Mini-LED Display
The following are the advantages:
• Improves the capabilities and applications of LED-backlit LCD when compared to other backlighting schemes.
• Can rival the deep blacks or high contrast ratios of OLED and microLED displays while offering superior brightness and outdoor visibility.
• It is a cost-effective alternative to microLED display technology. A micro-LED IPS LCD can rival both OLEDs and microLEDs minus cost.
• Micro-LED can improve further QLED or quantum dot LED LCD displays by equipping them with highly granular control over local dimming zones.
Below are the disadvantages:
• It is more expensive to manufacture than traditional LED-backlit LCD panels, thus limiting its applications in top-tier and high-range devices.
• Manufacturers of LED chips need to increase their production capacity to keep up with upcoming demands.
• It can inherit the disadvantages of the underlying LCD technology. Note that IPS, TN, and VA have their respective drawbacks.
FURTHER READINGS AND REFERENCES
- Horn, R-H., Chien, H-Y., Trantair, F-G., and Wuu, D-S. 2018. “Fabrication and Study on Red Light Micro-LED Displays.” IEEE Journal of the Electron Devices Society. 6: 1064-1069. DOI: 1109/jeds.2018.2864543
- Huang, Y., Hsiang, E-L., Deng, M-Y., and Wu, S-T. 2020. “Mini-LED, Micro-LED, and OLED Displays: Present Status and Future Perspectives.” Light: Science & Applications. 9: 105. DOI: 1038/s41377-020-0341-9
- Konsyse. 2020. “Difference Between Micro-LED and miniLED.” Konsyse. Available online
- Moore, S. K. 2019. “microLED Displays Expected in 2020: The Last Remaining Hurdle is Mastering Mass Production.” IEEE Spectrum. 56(8): 8-9. DOI: 10.1109/MSPEC.2019.8784111
