What is a full-array backlight?
An LCD panel doesn't make its own light; it filters light from a backlight behind it. In a full-array (also called direct-lit) backlight, LEDs are spread in a grid across the entire back of the panel instead of only along the edges. That gives more even lighting across the screen.
Many full-array displays add local dimming, known as full-array local dimming (FALD). The LEDs are grouped into zones that dim or brighten independently based on what's on screen, so dark parts of the image get darker while bright parts stay bright. That improves contrast and HDR. Manufacturers use the terms loosely: a basic direct-lit screen may have LEDs behind the panel but no dimming zones at all.
You may also see "full array" in storage articles, such as a full-array read during a RAID rebuild. That's plain English for reading every drive in the array, not a display term.
Backlight types compared
| Type | Where the light comes from | Strengths | Weaknesses |
|---|---|---|---|
| Edge-lit LCD | LEDs along the edges; a light guide spreads the light | Thin, inexpensive | Uneven patches or bright corners; few or no dimming zones |
| Full-array LCD | A grid of LEDs behind the panel | Even lighting; dimming zones when it has FALD | Thicker; blooming around bright objects |
| Mini-LED LCD | Many more, much smaller LEDs behind the panel | Far more dimming zones, less blooming | Some blooming remains; costs more than basic backlights |
| OLED | Each pixel makes its own light; no backlight | True black, per-pixel control | Burn-in risk with static images |
Blooming
Dimming zones are much larger than pixels. When a small bright object sits on a dark background, such as white text or a mouse pointer on black, the whole zone lights up and a faint halo appears around the object. This is called blooming. More zones mean smaller halos, which is the main advantage of Mini-LED. Local dimming can usually be turned down or off in the monitor's menu if it bothers the user.
For the CompTIA A+ exam
Full-array backlights aren't named in Core 1 (220-1201). Objective 3.1 lists LCD panel types along with OLED and Mini-LED, and backlights are what separate them: Mini-LED is an LCD with a denser LED backlight, while OLED has no backlight at all. A screen that's dim or dark while the image is faintly visible points to a backlight problem, which falls under objective 5.3 display troubleshooting.