The first OLED screens for use in mobile phones arrived in 2003 – almost all flip phones. And there is a simple reason why the screens were small and were placed as the secondary screen on the outside of the flap.
Some of them were able to reproduce 256 colors, although others were monochrome. Phones like Samsung E700 and LG G7030 had such color displays with 96x64px resolution while the inner screen was 128x160px which could deliver 65K colors (16-bit).
Samsung E700 • LG G7030 • Motorola V303 • Maxon MX-7990
OLED continued to be used exclusively on flip phones for the next few years, until the first AMOLED display came on mobile in 2006. These days, “OLED” and “AMOLED” are used somewhat interchangeably, but they are not the same. “AM” stands for “Active Matrix” and it is the key to having a high resolution, good quality.
We skip the details, but the important thing to note is that an Active Matrix attaches each pixel to a transistor and capacitor to maintain the state of the pixel. A passive matrix is simpler as it omits these components and saves complexity and cost. But it limits the screens to low resolutions and refresh rates.
Maybe we should also say a few words about LCD vs. OLED. An LCD has a backlight (typically white), and it blocks light from it using multiple polarizing layers (including a liquid crystal layer). An OLED – Organic Light Emitting Diode – does not need a backlight, as each LED emits its own light. There is also no need for polarization layers (although these can be useful as we will soon see).
Which phone was alerts about the AMOLED dominance we see today? BenQ-Siemens S88. This brand emerged when Taiwan’s BenQ bought Siemens’ struggling phone division, but folded fairly quickly after massive losses early on. In any case, the S88 had a 2MP camera with autofocus and LED flash, a memory card slot and basic 2G connection.
The BenQ-Siemens S88 was the first mobile phone with an AMOLED display
More important to our history today is the 2.0 ”AMOLED panel manufactured by AU Optronics. It had a resolution of 176 x 220 px and was able to display 256K colors. This resolution was not atypical of the era, although it is on the low side compared to some competitors. What sets it apart is its ability to show true variety. Although we may have rose-tinted glasses.
Reviewers at the time knocked on the screen for being weak (AMOLEDs were weaker than LCDs for many years to come). And in that size and resolution, true blacks were probably not a great blessing. Although AMOLED always offered vibrant colors, the color accuracy took something.
Things were pretty quiet after the S88 launch, at least until the Nokia N85 arrived in 2008. It had a larger 2.6 ”AMOLED display of much higher quality – 240 x 320 px resolution (154 ppi) and capable of reproducing 16M colors. It was a Symbian phone with a capable 5MP camera and a host of multimedia and other advanced features. After all, this was a successor to the Nokia N95, without a doubt the most capable phone of its time.
Samsung also joined the AMOLED party with the M7500 Emporio Armani, which arrived in December 2008, just a few months after Nokia launched. A few other Samsung phones were announced in 2008, but they would not hit the market until 2009.
There were also a couple of AMOLED-equipped Sagem phones with edgy Porsche Design … designs.
Samsung M7500 Emporio Armani • Samsung i7110 • Samsung i7110 • Sagem P9521 Porsche
Things really took off in 2009 with many iconic Samsungs. This includes the Samsung I7500 Galaxy, the first Galaxy phone ever (we will cover this in more detail in the future). There was also the Pixon12, several Windows Mobile and Symbian-powered Omnia phones, and the Samsung S8000 Jet, one of the most capable phones ever. Nokia released the N86 8MP, but it was clear that Samsung at the time was the biggest fan of the AMOLED technology.
Samsung I7500 Galaxy • Samsung M8910 Pixon12 • Samsung I8000 Omnia II • Samsung S8000 Jet
Still no Super AMOLED. As we mentioned in the story of the original Galaxy S, it may have popularized the new panel type, but it was not the first to use it.
It was the Samsung S8500 Wave from 2010. After launching Android, Windows Mobile and Symbian smartphones (not to mention dozens of feature phones), it is clear that Samsung had not settled on a single platform at that time. The Wave was the first of a series of phones to run the Bada OS (“bada” is Korean for “ocean”, hence the Wave naming of the series).
Samsung Wave had a 3.3 ”Super AMOLED screen with a resolution of 480 x 800 px (283 ppi) and a sheet of first generation Gorilla Glass on top. “Super AMOLED” is the name Samsung gave to a specific AMOLED panel that it developed – it had an integrated touch digitizer (the thing that senses when your finger touches the screen). Previously, the digitizer was a separate layer, but this leads to poorer optical qualities. Super AMOLED reflects much less light than a typical AMOLED touch screen during the day, as there is no space between the touch and the display layers.
Removing air gap from the screen is not the only way to improve the screen’s handling of strong ambient light. Nokia created what it called “ClearBlack” for its AMOLED monitors, a polarizing filter that greatly reduced glare. It was first shown on Nokia C6-01 and Nokia E7.
Samsung Galaxy S II is also known for our history as one of the first – and one of the few phones ever with an RGB AMOLED display. Most AMOLEDs then and now hold some event where individual pixels do not have the full RGB stripe.
AMOLED monitors soon developed another advantage over LCDs – they could be made on a plastic backing. This meant that the display itself could bend even though its protective glass (or indeed the rest of the phone) could not. This led to the first phones with curved screens that we covered last week. This included some flexible phones, though it was more of a party trick than a precursor to today’s flexible phones.
Samsung Galaxy Round was curved (but not flexible)
LG developed a curved, flexible display and battery for the G Flex
However, it is still only possible with AMOLED. Another is that the AMOLED panel is not opaque – you can put things behind it. Things like an optical fingerprint reader. The first phone to pull it out was the 2018 vivo X20 Plus UD (“UD” stands for “under display”). Here is our first meeting with the phone:
That was just the beginning. As quality improved, engineers were able to get a camera to work behind the screen – the first to bring this to market was the ZTE Axon 20 5G from last year. It was not perfect, neither the display nor the camera, but we have already seen second generation technology which showed improvement on both points.
Now that we have caught up with the current state of OLED on mobile phones, what does the future hold? There are two major challenges with OLED’s dominance mini-LED and microLED.
Despite being similar, the two are (literally) as different as LCD and OLED. The Mini-LED is actually just an LCD with smaller LEDs used in the backlight, allowing for a greater number of dimming zones. Micro-LED is basically OLED without the organic compounds in the LED make-up- these will be brighter, more efficient and will not suffer from combustion.
But micro-LED is not ready for prime time yet, which means that OLED will be with us for some time to come. Especially since costs have dropped and now even mid-rangers can have an OLED display.