IPS vs AMOLED vs SLCD – smartphone displays explained

You’ll spend most of your time looking at the display more than anything else but what are smartphone display panels made of?

As with any technology, smartphone display panels are a mega business on their own. Japanese component and notebook giant Toshiba has had to brush aside rumours that Apple was planning to invest in a new production line built by Toshiba Mobile Display, such is the demand of high-quality, high-resolution display panels.

But when you start looking at the specs of smartphone displays, it can get very confusing very quickly. You might think you’re just looking at a bunch of pixels but how those pixels are created can affect everything from the price of your phone to how long the battery lasts.

The type of display your smartphone has is typically described by an alphabet soup – LTPS, AMOLED, SLCD, Super AMOLED and TFT LCD all represent different technologies used in the production of display panels. Knowing what each type does, its benefits and drawbacks will help you understand just how good (or not) your phone is.

LTPS – Low-temperature polycrystalline silicon

If you see these written as a display type, forget it – LTPS is a description of a manufacturing process, not a display technology. Low-temperature polycrystalline silicon can be used to make different types of screens – AMOLED as well as standard LCDs. It’s a way of creating tiny silicon crystals that go into making the pixels of a display. The “low temperature” part is important because it means this process can create screens using low temperatures, allowing low-cost substances such as plastics to be used as the backing material on which the display panel is infused or created. As a result, it also means you can create more flexible display panels.

AMOLED – Active-matrix organic light-emitting diode

Okay, this is a type of screen technology. OLEDs or organic light-emitting diodes have been around for a while now and they have one significant benefit: to produce black, you simply turn an OLED off. To produce a light colour, they have to produce light. So they have huge potential for power savings in mobile devices.

The “Active matrix” describes how each OLED is addressed or controlled. The alternative is a passive matrix display where rows or columns of OLEDs are addressed rather than individual pixels. As a result, AMOLED displays are not only brighter, use less power, they’re also faster.

The problem is that AMOLED panels are in high demand, with that demand exceeding supply.

The other issue with AMOLEDs is that because of the fabrication process, they can be difficult to see if viewed in direct sunlight. AMOLED panels are typically three layers, the AMOLEDs, the touch-panel sensor layer made of glass and then the top glass protective surface with air in between each layer. The diffusion of light through all three layers causes the AMOLED light to be diffused and difficult to see.

AMOLED panels are used in a number of phones including Google’s Nexus One and early versions of the HTC Desire.

Super AMOLED

So Korean giant Samsung decided to come up with a different method that combined the top glass layer and the touch-panel glass layer into one.

This promotional video gives you a brief overview of Samsung’s Super AMOLED technology.

By reducing the number of layers and removing one air gap, light dispersal is reduced, making these AMOLED displays easier to see in bright light.

Samsung uses the Super AMOLED panel in its Galaxy S phone and is expected to use it inside the upcoming Nexus S.

SLCD – Super liquid-crystal display

LCD has been the mainstay for display panels from PDAs to notebooks to TVs over the last 15 years or so. What makes Super LCD so super is said to be improved light bleeding so that blacks actually look a bit more like black than they typically used to, giving better overall contrast. In comparisions with AMOLED, some reviews suggest that SLCD gives warmer colours than AMOLED. However, battery life appears to be worse with SLCD displays.

SLCD shouldn’t be confused with S-LCD, which is the name for the Samsung/Sony joint venture for manufacturing LCD panels.

Smartphone maker HTC began using SLCD panels in its Desire smartphones in August 2010 due to shortages in AMOLED panels from Samsung. If you have an early Desire, it’ll more likely have an AMOLED panel whereas those manufactured after August 2010 will have an SLCD panel instead.

IPS – In-plane switching

Apart from poor contrast ratios, the other issue with LCD panels is poor viewing angles. The further you move of the centre axis of an LCD panel, the worse the image becomes until you begin to see the reflected negative of that display. In-plane switching is a more expensive solution to the viewing angle problem by changing the direction in which the liquid crystal molecules move. So instead of the normal right-angle or perpendicular switching, IPS panels switch molecules in the same plane as the panel. It means light transmitted through the molecules can be seen at (almost) any angle.

IPS technology is most often used in LCD monitors – and usually at prices three times the going rate. It’s the technology behind Apple’s Retina display in the iPhone 4.

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Super AMOLED Vs Retina Vs OLED Vs LCD Vs IPS: What’s the Difference?

There’s no denying that there are LOTS of different Android phones on the market, and what there also happens to be lots of are different types of displays. I don’t know about you guys, but I think it can get pretty confusing hearing about Super AMOLED, Retina, OLED, LCD, and IPS displays, so I thought I would do my best to explain some of the key differences between all of the different types of displays you can find on smartphones.

LCD

LCD displays start with a backlight that’s always on, and require light in order to create black, white, and colors. High end LCD’s have the reputation for creating the most accurate colors and “grays”, but are often calibrated (on purpose) to produce weaker red, blue, and purple colors to keep power consumption down. LCD screens also age slower, and can easily withstand thousands of hours of use.

OLED

This particular type of screen requires no light in order to produce black, but only needs it to produce white and colors. Because of this, it can be considered as a battery saving display. OLED displays are often brighter, but can often suffer from oversaturated green colors. They also age a lot faster than LCDs, with red and blue colors deteriorating faster than green. That might not sound like a big deal, but it can cause the color balance to suffer over time. OLEDs are also more expensive to make, which has caused many manufacturers (HTC for example) to switch from AMOLED to LCD displays.

Super AMOLED

Don’t let the title “Super” fool you. This is simply Samsung’s proprietary name and approach to making OLED displays. In other words, Super AMOLED=Samsung OLED. Super AMOLED, Super AMOLED Plus, and HD Super AMOLED only really have one major difference: sub pixels.

Screen pixels are generally made up of red, green, and blue sub pixels that combine to create other color combinations. For example, Samsung’S Super AMOLED uses Samsung’s PenTile layout, and the same pattern of red, green, blue, and green sub-pixels, which typically has fewer sub pixels than the layout used in LCD displays. The larger sub pixels are effective in letting in more light, which lead to brighter and smoother images, which is seen on the Galaxy S2, Samsung Droid Charge, and the Samsung Infuse 4G. Super AMOLED HD is simply the same PenTile Super AMOLED display, but with a higher resolution of 1280 x 720. These screens are featured in the Samsung Galaxy Nexus, Galaxy Note, and the new Samsung Galaxy S3.

IPS and Retina

IPS , which stands for “in plane switching, is actually a premium LCD technology that’s known for having a wide viewing angle and clear picture. You can find this display in the iPhone 4 and iPhone 4S. The “Retina Display” that Apple uses is based on IPS technology, and if you’ve ever seen an iPhone in action, I’m sure you can attest to how great the screen is. The Transformer Prime features an IPS display, and I can personally attest to how great the colors are. The newly announced Transformer Infinity will feature a "Super IPS" display 1920 x 1200.

And the best display is?

So which type of display is best? There’s no real answer for that, as it will most likely boil down to personal preference. I personally prefer IPS and Super AMOLED displays, but that certainly doesn’t mean that any one display is better than the other. They all have their strengths and their weaknesses, with some having more textured and brighter colors, while others produce colors differently to reduce battery consumption.

So next time you’re browsing around the shop looking at different phones, try to see if you can spot the differences in the displays. Keep in mind that this article was only to provide a brief overview of the key differences of the displays, as there are obviously other technical factors that come into play with their individual construction. With some you might see nothing, but for others you might notice a considerable difference. The infographic that we made back in early May (below) tells you which types of displays are featured in 7 popular Android phones, and could help to provide a bit of an overview of which phones carry which displays. - Source

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Lumia 900 display beats Galaxy S and iPhone 4 displays in visibility tests ?

AMOLED displays, although beautiful to look at, have had issues performing under bright sunlight. The first phones to use AMOLED displays were barely usable outdoors. Eventually the technology improved, specifically when Samsung introduced their Super AMOLED displays, which had significantly better outdoor visibility, and these days AMOLED displays are even outperforming LCDs when it comes to visibility under sunlight.

One such AMOLED display belongs to the Nokia Lumia 900, which despite its AMOLED nature performed very well under bright light, thanks to Nokia’s Clear Black Display technology, in a comparison test performed by DisplayMate. Compared to the Galaxy S and the iPhone 4, the display on the Lumia 900 came out on top with 90 points, with the Super AMOLED display on the Galaxy S narrowly managing to get the second position with 80 points and the LCD on the iPhone 4 coming in at third with 77 points.

They also had older phones such as the Motorola DROID X and the HTC Desire and you can see from their poor scores of 20 and 15 points respectively how much further AMOLED technology has come in the past two years alone.

We just find it curious as to why DisplayMate chose to compare the Lumia 900 with two year old phones like the Galaxy S and the iPhone 4. Something more recent such as the HTC One X and the upcoming Galaxy S III would have made much more sense.

You can find the results of their test in the link below. - Source

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Huawei Ascend P2 vs Galaxy S3 vs HTC One

Hauwei unveiled some pretty snazzy phones at CES last month, but the company isn’t done trying to impress smartphone buyers around the world. At Mobile World Congress Huawei unveiled the Ascend P2, a follow up to the P1, that bears the promise of being the world’s fastest smartphone. The speediness Huawei claims is not just in the processor, but in the data connection as well. By utilizing LTE Cat-4 generation networking, the P2 can achieve speeds of 150 megabits per second (the iPhone 5 gets 100Mbps). The Ascend P2 even charges faster thanks to 2-amp charging that gets the battery full in less time.

With it’s 4.7-inch display featuring 500 nits of brightness to show off a heavily customized UI on top of Android, the Ascend P2 is in direct competition with Samsung’s Galaxy S3 and the new HTC One.

Here’s how it compares:

Specification	Ascend P2	Galaxy S3	HTC One
Size	8.4 thick (mm)	136.6 x 70.6 x 8.6 (mm)	137.4 x 68.2 x 9.3 (mm)
Weight	122g	133g	143g
Screen	4.7-inch IPS	4.8-inch Super AMOLED	4.7-inch LCD
Resolution	1280×720 pixels	1280×720 pixels	1080p
OS	Android 4.1 with Emotion UI	Android 4.1 with TouchWiz UI	Android 4.1.2 with Sense 5
Storage	16GB	16/32GB	32/64GB
SD Card Slot	TK	Yes	No
Processor	1.5GHz quad-core	Dual-core Snapdragon S4 (US)	Quad-core Snapdragon 600
RAM	1GB	2GB	2GB
Connectivity	Wi-Fi, 4G LTE	Wi-Fi, 4G LTE, HSPA+	Wi-Fi, 4G LTE, HSPA+
Camera	Front 1.3MP, Rear 13MP	Front 1.9MP, Rear 8MP	Front 2.1MP, Rear 4MP
Bluetooth	Yes	Yes, version 4.0	Yes, version 4.0
Battery	2420mAh	2100mAh	2300mAh
Charger	Micro USB	Micro USB	Micro USB
Marketplace	Google Play Store	Google Play Store	Google Play Store
Price	€399	$200+	TBA
Availability	Orange (EU), unlocked (US)	AT&T, Sprint, T-Mob, Verizon	AT&T, T-Mob, Verizon

The Ascend P2 holds up well in comparison to the new HTC One flagship phone, and out-specs the Galaxy S3 (admittedly an “old” handset) in several areas. What’s surprising is that the P2 doesn’t have full 1080p resolution, which is the trend for new Android smartphones in this size class. It’s great that the phone has wide viewing angles, can be used even with gloves like the new Nokia Lumias, and is protected by Gorilla Glass. Will the lack of full HD matter to everyone?

Huawei is taking the same route as Samsung, HTC, and even LG in putting a heavily customized skin over Android and bundling in a ton of apps and services to enhance the Android experience. Some people love this approach and others really hate it, so the Emotion UI may prove polarizing. That 1GB of RAM could prove a problem in this area.

The 13 megapizel camera on the back is another of Huawei’s selling points. As HTC reminded us recently, megapixel count isn’t the only thing that determines pixel quality. The promise of HDR (high dynamic range) photos and video plus sharper pictures using digital zoom point to a camera that will give even HTC’s ultrapixels some competition.

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