Many top-rated TVs being made and sold today require backlight of some sort. These TVs feature a liquid crystal display (LCD,) and LCDs do not provide their own light. Because they lack their own light source, LCD TVs must have a backlight. Therefore, consumers may have to consider what does backlight mean on a TV.
KEY TAKEAWAYS:
- LCD TVs require a backlight to show any image on the screen.
- CCFL or LED lights provide LCD TV backlights.
- Several arrangements exist for LED panels, including full array, local dimming, edge, and mini-LED.
What Does a TV’s Backlight Do?
Before introducing liquid crystal displays, many households owned a cathode-ray tube (CRT) TV that did not need a backlight. However, as broadcasters switched to digital, CRT TVs became less common. LCD TVs are significantly lighter, thinner, and brighter than CRT TVs. LCD TVs use liquid crystals with polarizers to alter the light being shown through them. Additionally, LCD TVs use color filters to create red, green, and blue (RGB) characteristics. It is, however, worth noting that LCD technology is quite outdated which is why you may be asking yourself what causes your TV to pixelate.
The backlight on an LCD TV comes from a light-emitting diode (LED) or cold cathode fluorescent lamps (CCFL) panel. These panels provide the light required to show images on a TV. LCD TVs’ primary type of panel is LED, though some TVs may still use CCFL. LED panels come in various styles, including full-array, local dimming, and edge-lit arrangements.
CCFL backlights
When LCD TVs were first introduced, they included cold cathode fluorescent lamps (CCFL) to work as their backlighting. It is referred to as a cold cathode because a filament does not heat the cathode electrically. Instead, the cathode emits its electrons. Many electronics use these lights, including neon lamps, discharge tubes, and some vacuum tubes. CCFL TVs feature two CCFLs placed at opposite ends of the display or with an array of CCFLs. Unfortunately, these TVs required more power, had a thicker design, aged faster, and lacked high-speed switching.
LED-backlit LCD
Most LCD TVs contain a light-emitting diode (LED) backlight because this technology is more prevalent than CCFL. Because of this popularity, LCD and LED TVs are pretty much the same things. However, LED TVs provide a wider color gamut and dimming range than CCLF backlights. Additionally, these TVs feature a more fantastic contrast range and typically 20-30% lower power consumption and long lifespan. LED TVs are also more reliable, as well as being lighter and cooler. Also, you can check out what is an OLED TV.
There are several different array types for LED TVs, including:
- Full-Array LED panels have lights along the entire back of the LCD in a grid pattern. These panels offer consistent lighting across the screen, but they do not include dimming in specific areas.
- Local Dimming LED panels often have lighting along the entire back of the display, but they allow lights in specific areas to be turned off separately. These panels help to eliminate bleed-through of nearby lights in dark areas of the screen.
- Edge-lit LED panels feature LED lights along only the edge of the display. These TVs are not uniformly lit along the back and do not feature lights that the TV can turn off individually.
F.A.Q.
Why does local dimming exist?
Brands created local dimming displays to aid in the enhancement of dark areas on the screen. These displays allow only certain regions of the screen to have a backlight.
What are edge-lit LED TVs?
Manufacturers arrange edge-lit LED TVs’ lights along only the edge of the picture. Although the whole image is lit, the limited lighting can cause ambiguity in the display.
Do I need a backlight on my TV?
Many TVs require a backlight now. However, these TVs already contain these backlights, and you do not need to purchase additional lighting for them.
STAT: Typically 20–30% lower power consumption and longer lifespan (source)
