However much credence you place in the rumours from the supply chain about Apple investigating AMOLED technology for future iPhones, we thought a little background and context was in order. I, for one, am very sceptical, as I’ll detail below. There’s no doubting the beauty of AMOLED under certain specific circumstances – it’s just not that well suited to iOS or to typical iPhone long-term use. So let’s look at the pros and cons of each display technology – when does each shine?
A brief technology recap though – AMOLED stands for Active Matrix Organic LED, with its pixels generating light individually upon being electrically stimulated. So pixels which aren’t stimulated are – quite genuinely – black. While those that are shine with a vivacity that isn’t possible with a conventional In-Plane-Switched (IPS) LCD display, which relies on a backlight (typically a line of bright white LEDs at one end) illuminating LCD pixels across the display surface.
Typically, AMOLED screens have been used by high end Samsung smartphones, along with a number of Nokia and Microsoft Lumias, all of which rely to an extent on saturated colours and which work well with dark themes, while IPS LCD screens have been used by Apple and many other manufacturers, often with white or bright themes.
Let’s look at the pros and cons of each approach in detail:
AMOLED advantages:
- Uses less power when displaying a dark-themed screen, i.e. an interface with white text on dark background.
- ‘Blacker blacks’ possible, with impressive results in true black themes or, more likely, when displaying media, such as movies or music videos.
- ‘Glance’ screens become more practical, always-on displays providing time, date and notifications, depending on the OS (of course) because you only have to ‘light up’ the pixels needed, which is very power efficient.
- The display can be slightly thinner, since no backlight layer is needed. With the race to thinner and thinner phones, this factor is increasingly important.
- Can be made flexible (though this is only used at the moment in Samsung’s top-end ‘Edge’ phones.
AMOLED disadvantages:
- Uses dramatically more power (up to ten times!) when displaying a white-themed screen. In practice this means almost all web sites and web services, unfortunately, plus most of iOS’s default interface.
- Requires a ‘pentile’ layout at modern (high) resolutions, leading to slightly fuzzy text if you look closely enough. In practice, if the resolution is high enough then this ‘fuzziness’ is beyond human eyesight limits.
- Tends to ‘burn in’ if there are UI elements which stay on screen for long periods (e.g. top-of-screen status bars), due to natural degradation of the organic polymers in the AMOLED pixels.
- The overall brightness reduces with age, again as the organic polymers degrade.
- Tend to be more expensive to manufacture than LCD, which is why you usually find the latter on budget phones (e.g. on Android).
LCD advantages:
- Power drain doesn’t vary wildly according to displayed content – so bright or dark themes and displays don’t affect battery life much. Which is good for iOS and for the Web and Internet services in general.
- More accurate colour balance, including ‘whiter whites’ – getting AMOLED pixels to display white means driving them very hard, whereas white is a piece of cake for LCD, since that’s the colour of the original backlight.
- A full RGB (Red/Green/Blue sub-pixels) matrix is used, giving crisper results for a given resolution. So ‘1080 pixels’ in width means just that (and not 1080 green and 540 red and blue sub-pixels, as in pentile AMOLED displays).
- Screen ‘burn in’ is very slow, significantly exceeding the life of the device.
- The brightness stays constant across many years (again, dimming would require a decade of regular use, a lot even for an iPhone!)
- Tend to be cheaper to manufacture (though Apple’s use of 3D Touch bumps up the cost, but that’s another article for another day).
LCD disadvantages:
- ‘Glance’/always on-screen elements are either not practical or have to be backed by a noticeable ‘all over’ glow, certainly when seen in dead of night. In practice, this isn’t something Apple has ever aspired to, but it’s worth noting.
- The display has to be slightly thicker, due to the need for a backlight plane.
AMOLED or LCD for Apple then?
In compiling the lists above, as you might have spotted from some of the commentary, there’s far more to Apple’s advantage in staying with IPS LCD than switching to AMOLED for iOS. The one major advantage would be that the display could be thinner, especially if the 3D Touch technology could be integrated, but set that against the disadvantages of AMOLED and my opinion, for what it’s worth, is clear.
You see iPhones have long lives. Even today, in 2016, I’m seeing quite a few people still using the iPhone 4S, from 2011, i.e. well over four years old. With excellent resale value and good engineering meaning that any single device is expected to last at least this long, opting for a screen technology which will be ‘degraded’ well before the device reaches the end of its life really isn’t a good move. Add in the amount of ‘white’ in iOS, from the default panes to web pages to Twitter and Facebook to the various Office applications, wherein an AMOLED screen would decrease the battery life of a typical iPhone by a factor of two – at least, and there really shouldn’t be any argument.
Of course, the finer details of 3D Touch and Apple’s plans to produce version two of this tech still aren’t known – the current solution is too heavy and bulky. And something else occurs to me – if iPhones 3D Touch and Apple’s plans to produce version two of this tech still aren’t known – the current solution is too heavy and bulky. And something else occurs to me – if iPhones were made with AMOLED screens that – typically – gradually lost their zest and started burning-in, then there would be yet one more reason for people to buy a new iPhone every two years. More guaranteed sales, eh?
Still, at least you’re armed with details on the two rival display technologies now. Just don’t blame me in 2018 when your iPhone 7 Plus starts showing status bar burn-in when you’re trying to concentrate on a game!