The image brightness of a liquid crystal display (LCD) essentially depends on how bright the backlight is and the efficiency of the liquid crystal in controlling light. Below is a simplified yet professional explanation:
I. What is "Brightness"?
Brightness: Refers to the intensity of light emitted by the screen, commonly measured in cd/m² (nits).
Higher values result in clearer images in bright environments.
Common ranges:
Ordinary computers/monitors: 250–350 nits
High-brightness monitors/outdoor screens: 500–1000+ nits
Mobile phones (peak): 800–2000 nits (HDR)
II. How is LCD Brightness Produced?
LCDs themselves do not emit light; brightness comes from the backlight (usually LEDs).
Simplified structural understanding:
LED backlight → Determines the "maximum brightness limit"
Liquid crystal layer → Acts like a "light valve," controlling how much light passes through
Color filter → Separates into RGB, further reducing brightness
Polarizing filters (two layers) → Significantly weakens brightness (key loss)
Therefore, even if the backlight is very bright, the light that actually reaches your eyes is "reduced layer by layer." III. Main Factors Affecting LCD Screen Brightness
1. Backlight Intensity (Most Crucial)
Number of LEDs, power, driving current
Directly determines maximum brightness
2. Panel Type
TN: High brightness, low cost
IPS: Slightly lower brightness, but accurate colors
VA: High contrast, medium brightness
3. Screen Transmittance
Liquid crystal material, polarizer quality
Higher transmittance results in brighter images and lower power consumption
4. Surface Treatment
Matte screen: Anti-reflective, but slightly lower perceived brightness
Glossy screen: More transparent, but strong reflections
5. Display Content
White screens are brighter than black screens
Local areas are particularly bright in HDR mode
IV. Brightness ≠ Clarity
Also consider:
Contrast (how dark the blacks are)
Ambient light (indoor/outdoor)
Color mapping and gamma
Whether automatic brightness is enabled
For example:
300 nits + high contrast → Very clear indoors
600 nits + low contrast → May still appear dim outdoors
V. Common Misconceptions
❌ “Higher brightness is always better”
✔ Excessive brightness can be dazzling, consume more power, and shorten backlight lifespan
❌ “Adjusting brightness = adjusting color”
✔ Brightness mainly affects the backlight, not color accuracy