The backlight is always on, and the pixels in the display rotate to allow light through, creating the colors needed for the image. If the screen wants to display black, the LCD pixels rotate to try to block the light completely. If it wants to display white, it lets all light through.
Since the display is only a filter, the blacks will not be as deep as with a plasma screen because an LCD panel will always let a small portion of light through. There are different types of LCD panels, each with its unique characteristics. Vertical Alignment VA panels generally have a high contrast ratio and narrow viewing angles, while In-Plane Switching IPS panels have a low contrast ratio with wide viewing angles.
You can read about their differences here. The backlight is a series of light tubes placed behind the screen. These tubes are very similar to fluorescent lamps used in buildings but smaller.
Also, LED TVs have more control over their backlight, resulting in vivid colors and better picture quality. There are three main configurations of LED as backlights for television screens: full-array, edge-lit, and direct-lit.
This method is considered the best LED backlight type and is usually found on higher-end models, but as of , some mid-range models have it too. This produces a more uniform backlight and provides more effective use of local dimming , where it can turn off and dim complete zones of LEDs.
Depending on the display, it can be all around the screen, on the left and right sides, or at the top and bottom. This allows the screen to be very thin. However, it can cause some spots on the screen to be brighter than others, like the edges. This problem is called flashlighting or clouding. It can be seen when watching a dark scene in a dark environment.
Also, edge-lit screens usually don't result in good local dimming as they don't have control over the dimming zones. Like the full-array method, the LEDs are directly behind the screen. However, there are very few of them, and they can't be controlled separately to match the luminosity of the picture.
This allows for more lights, creating a brighter image and more control over local dimming. Only a handful of Mini LED TVs were produced before , but it now seems that manufacturers are starting to use the technology more often. Another technology, Micro LED, is only in its initial phases of development.
Plasma and LCD each present advantages and disadvantages when it comes to picture quality. Plasma TVs generally offer better contrast, wider viewing angles, and improved response times, while LCD TVs get much brighter and have better reflection handling. LCDs also cost less and can be much thinner, which are two of the main reasons why they took over the market share from plasmas in the mids.
Get insider access. Best TVs. TV Recommendations. View all TV recommendations. All TV Reviews Samsung. The Frame C1 OLED. A1 OLED. In the post about the operation of LCD, I already explained how the liquid crystal works and how it polarizes the light, click in the button below to see. The backlight LEDs emit white color, which is the sum of all other colors. Each pixel has filters of three primary colors: blue, green and red.
The pixel color depends on the polarization of liquid crystals, which are controlled by thin film transistors. The combination and intensity of three primary colors can produce all other colors. Thanks with regards. Very informative and comprehensive article. I have been looking for a such detailed explanation for some time.
LCD stands for liquid crystal display. The liquid crystals block or allow light to pass through them. The different colours and brightness levels created by the liquid crystals and various filters become the picture on the screen. The liquid crystals don't create light, though; that job falls to the backlight. LED stands for light-emitting diode, and these make up the backlights of some TVs.
The LEDs either sit behind the screen this is called full array or at the edge of the screen known as edge-lit. The backlight creates the light, which passes through the liquid crystals, along with a few other filter layers, to create the picture. Instead, these TVs typically use older fluorescent backlights.
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