The Difference Between An LCD And An LED Backlit LCD Display

Modern technology is incredible – a marvel of ingenuity, creativity, and talent. The technological revolution of the past century has changed the world mostly for the better. Alongside the technological innovation, a new vocabulary has had to develop to explain the latest advances in technology

Nowhere is this more clear than in the television market. Understanding terminology can be critical to getting the best quality at a decent price when upgrading your TV. So what exactly is the difference between an LED and LCD display?

?What Is LCD

A Liquid Crystal Display (LCD) is one of the most enduring and fundamental technologies used in most monitors, televisions, tablets and smartphones. TVs and other monitors used to use cathode ray tubes (CRTs) to provide the image onto the screen. Once LCD displays became affordable they quickly displaced the bulky CRTs

An LCD features a panel of of liquid crystal molecules that can be induced by electricity to take certain patterns which either block or allow light to pass through. The an LCD TV has a light source at the back of the display which lights up the crystals. LCDs commonly use Cold Cathode Fluorescent Lamps (CCFL) to provide the backlight.

In order to provide a color image on your screen the LCDs have red, green, and blue sub-pixels in each screen pixel. Transistors within the display control the direction of the light emitted in each pixel, which is then passed through either a red, green, or blue filter.

?What Is LED

Light Emitting Diodes (LEDs) are small semiconductors that emit visible light when an electrical current is passed through them. Although the light is often not particularly bright, they are typically more efficient and longer lasting than traditional lighting

While LED is often used in place of LCD by many manufacturers, an LED TV is actually a type of LCD. Instead of using CCFL tubes to provide the LCD’s backlight, rows of LEDs give better control of the light provided to the display and at greater efficiency as it’s possible to turn off individual LEDs when they aren’t needed.

Is only life were as simple as to present you with only one choice; LED or CCFL LCD. However, it’s a little more complicated than that. If you choose to go with an LED display you have a selection to make between Edge-Lit, Full Array, and RGB-LED.

Edge-Lit LED

In an Edge-Lit LED TV, the LEDs are arranged around the rim of the display behind the LCD panels facing in towards the screen. This allows the display to be slimmer and use fewer LEDs, bringing the cost down. The light is reflected across the screen uniformly to create the image.

However, Edge-Lit LED displays are going to be brightest closer to the LEDs. This means that uniformity may be an issue with some areas appearing darker than others.

Full-Array LED

A Full-Array LED display has a grid of LED lights behind the LCD display. The LEDs shine directly outwards towards which creates a bright and uniform picture. Although Full-Array LED displays enjoy the efficiency benefits of LEDs, they are similar to CCFL LCDs.

For the best image reproduction, a Full-Array LED display can include local dimming. This means that groups of LEDs can be turned on and off when required to provide better control of the brightness. A Full-Array LED display with local dimming is often referred to as a FALD LED display.

RGB-LED

While LEDs are often referred to as emitting white light, they actually produce a light that is closer to yellow than a pure white. This sometimes create a color shift in the image you see on the screen. In order to improve on this some manufacturers replace the white LED with a grouping of red, green, and blue (RGB) LEDs. When used together, the RGB LEDs create a pure white and generally truer colors across the spectrum.

In order to control the RGB LEDs accurately, the displays require more complicated electronics and programming, as well as more LEDs. This significantly increases the cost of RGB LED displays, but for what most viewers would call a marginal improvement. Because of their higher cost, RGB LED displays have never truly become mainstream. Although, Dell has been known to produce a few like the Studio XPS 16 laptop

?Which Will You Choose

Before you go hunting for your next TV upgrade it’s worth making sure you know what features are important to you. If keeping the cost down is an important factor then it’s worth considering an edge-lit LED display. If image quality is your priority then a full array or RGB LED display is the choice

And although manufacturers and sales clerks often like to upsell with terminology, you can now say you know your CCFL LCDs from your RGB LED LCDs to make the best choice for your next upgrade.

Do you have a preference for LED or CCFL LCD? Do you think one is better than the other? Or, do you think there are more important TV features to think about? Let us know in the comments below

Source: makeuseof

 

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