Full array local dimming (FALD) can achieve simultaneous contrast ratios of 20,000:1 to 500,000:1.
Local dimming is a backlight technology used in LCD TVs and monitors to improve picture quality, particularly the contrast ratio. It works by dividing the backlight into zones that can be individually controlled. This allows the TV to dim the backlight in dark areas of the screen while keeping it bright in lighter areas, resulting in deeper blacks and brighter whites.
There are different types of local dimming, each with varying levels of performance:
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Edge-lit local dimming: LEDs are placed along the edges of the screen. This method is less effective because light bleeds from bright areas to dark areas can occur.
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Direct-lit local dimming: LEDs are placed directly behind the screen. This offers better contrast than edge-lit, but still doesn't match the performance of full-array local dimming.
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Full-array local dimming (FALD): LEDs are arranged in an array behind the entire screen. This allows for the most precise control over the backlight and offers the best contrast ratio performance. FALD with a higher number of dimming zones generally provides better contrast and less blooming (light bleeding around bright objects).
The specified contrast ratio of 20,000:1 to 500,000:1 refers specifically to Full-Array Local Dimming (FALD) implementations. The actual contrast ratio achieved depends on the number of dimming zones and the sophistication of the processing algorithms. More zones generally equate to finer control and a higher effective contrast ratio.
