Google IO 2017 Coverage

How LCD technology works

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Two of the most predominant display technologies in the smartphone market are AMOLED and LCD. We’ve already told you how AMOLED displays work and the technology behind them, and now, we’re going to show you how LCD displays work. By knowing what’s going on behind-the-scenes, you can make a more informed buying decision, and hopefully, have a more pleasant experience with your smartphone by choosing the handset with the right display for you.

What is an LCD display?

If you weren’t sure before, LCD stands for Liquid Crystal Display. The technology behind it all can get very complicated, but in layman’s terms, liquid crystals, polarized glass, circuitry, a backlight and color filters all work together to produce a crystal clear image.

If you remember when we talked about how AMOLED panels worked, there were some definite notable differences under the hood between AMOLED and LCD. AMOLED panels don’t use liquid crystals or a backlight, so LCDs are significantly different and a tad bit more complicated since AMOLED has a simpler design/construction.

How do LCD displays work?

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Like I said, LCDs are significantly more complicated than AMOLED. A combination of liquid crystals, polarized glass, circuitry, a backlight and color filters are all used to provide you with the end-image.

You have liquid crystals which can twist and untwist based on whether electricity is charged to them or not. With this, you can control the frequency of the emitting light. Combined with a couple of pieces of polarized glass, you can ultimately control the actual flow of light through the twisting and untwisting of these liquid crystals.

LCDs aren’t able to produce any light by themselves, though. So, things get even more complicated and crowded in the panel, as a small fluorescent lamp or row of LEDs are required to produce this light. This is commonly referred to as the backlight in an LCD panel, something AMOLED panels don’t need since they use an insane amount of small and colored light emitting diodes (LEDs) to produce that light. It sounds similar, but by doing it that way, you can get an overall simpler construction with the display. That isn’t the case with the LCD.

Here’s how uBreakiFix explains how it all works together to eventually product that end-user image:

“A backlight assembly creates an even light source that passes through the first glass polarizer, while at the same time, electric current allows the liquid crystal molecules to align in a way that allows differing levels of light to pass through the second piece of polarized glass. This manipulation of the light allowed to pass through the second piece of glass is what creates the images you then see on your smartphone or other electronic device.”

HowStuffWorks has a nice visual representation of how that looks:

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Ok, that’s how you see the image on your smartphone, right? But, what about color? It can get quite complicated, but uBreakiFix sums it up again quite nicely:

“To apply the electrical current required to manipulate liquid crystals, LCD manufactures use a thin grid of transparent transistors.  Each transistor represents a single area in which an electric current can be applied to produce a unique shade, and is referred to as a “sub-pixel”. Each sub pixel is then filtered through one of the three primary colors, red, green, or blue. By manipulating and varying the electric voltage applied, each sub-pixel’s intensity can range over 256 shades. The combination of three sub-pixels, creates one pixel.

When sub-pixels are combined, it is possible to produce 16.8 million colors (256 x 256 x 256) since the eye only sees blended colors as a result of the three independent sub-pixels.”

In both AMOLED and LCD you have something called color gamut. Color gamut is often described as the range of available colors that can be displayed on a device, in this case a smartphone. Often LCDs are said to offer the most natural looking colors, largely because the types of media we consume fit into the default/standard RGB color gamut. Of course, this isn’t always the case, since some manufacturers tend to mess saturation and ultimately the overall color balance.

It’s important to note that this gets all very technical and complex, obviously. It’s really nothing to be concerned about when buying a new device though — all that end-users need to know is that because of this LCDs often have more realistic-looking colors while AMOLED might have some more vibrant and deeper colors, some might say. And it’s true, mostly anyway. AMOLED panels are made with overall more vibrancy, making those displays look a lot more colorful than what you might find on an LCD panel.

AMOLED or LCD?

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Still, it really comes down to a matter of taste and opinion. Preferences of LCD or AMOLED come down to the opinion of individual people. In other words, there isn’t one that’s better than the other, and that’s largely because we all view colors differently than another person.

All you really need to know is that, chances are, you’ll find deeper and more vibrant colors on AMOLED. If you want something that aims at closely resembling real-life colors, you’re more likely to find that on a smartphone with an LCD panel. But, once again, color really comes down to a matter of opinion. I know, it’s a cliche saying, but it’s very true. Everyone sees color differently and have different preferences of what they like, so it really is hard to nail down whether one is better than the other. But, this at least gives you a place to start shopping around.

It’s worth noting that LCDs do generally draw much more power than AMOLED since they have a backlight that has to be constantly powered, whereas AMOLED panels don’t. But, in the time you have the device, it really isn’t going to impact your experience significantly, if you notice anything at all. The battery drain really isn’t going to be increased much either.

Closing

When it comes down to it, the technology behind both LCDs and AMOLED is really interesting. By understanding some of what happens behind-the-scenes, you can make a better informed buying decision for your next smartphone. Do you want it to have an LCD or Super AMOLED/AMOLED screen? Well, now you can make an informed decision on why you might prefer one over the other, and ultimately, end up happier with your purchase.


About the Author: Brad Ward

Brad is a tech enthusiast, writing and tinkering with all things technology since 2011. He currently bounces between the LG G3 and his beloved Moto X! His interests include reading, entrepreneurship, the gym, and of course, queso.