Until recently, smartphones were rapidly developing. 5-nm process technology in chipsets, displays with a resolution of 4K, 108-megapixel matrices, support for 5G networks - progress is obvious. One of the important aspects of every modern mobile device has always been the technology of displaying information. Devices from the premium segment gravitate to matrices based on organic light-emitting diodes. Only today they guarantee 100% deep black colour and unprecedented contrast. OLED technology has existed since the early 2000s, and today AMOLED and POLED are separately distinguished in their ranks.
OLED – matrices based on OLED technology
To create an image, a current is passed through organic diodes on the glass substrate of such a matrix. Light-emitting pixels generate only blue and yellow. They combine into a white stream that passes through the red, green, and blue subpixels to create a single pixel of the desired colour. Each pixel in the OLED sensor processes its colour and glows independently. Therefore, a separate layer for illumination, in this case, is simply not needed. This is the defining nuance of technology.
An important feature of OLED matrices is the deepest possible black colour. This is a direct result of how the technology works. When a specific shade does not need to be shown on a certain part of the screen, it is simply turned off. The same feature allows you to implement an always-on screen (important information on a black background on a locked screen) without harming autonomy. Another significant plus of OLED technology is high contrast. Theoretically, it reaches 1,000,000 to 1 because this value is measured by comparing the brightest and darkest parts of the screen. Such a high contrast makes it possible to achieve incredible impressions from the bright elements of the picture.
OLED displays are thought to be more energy-efficient than liquid crystal panels. However, when using high brightness levels, they consume battery power with much more “enthusiasm” than equivalent LCDs. Therefore, low energy consumption is a very relative indicator.
POLED – OLED with flexible polymer substrate instead of glass
Structurally, POLED is not particularly different from OLED. The main difference is the use of a flexible polymer substrate instead of a glass one. It seems that this does not matter much, but in fact, such matrices turn out to be more universal, modern, and also durable. The main advantage of POLED is greater impact resistance. Moreover, the use of a pliable substrate allows you to design folding and rolled gadgets, as well as ultra-compact devices. In the latter case, you can hide the necessary electronics behind the conditional rotation of the matrix.
💡 It is important to understand the difference between POLED and pOLED. The latter is LG’s trademark used for its proprietary OLED displays with a plastic substrate. The Korean manufacturer makes matrices for a large number of brands, including Apple with smartwatches and Google with some smartphones.
AMOLED — OLED screens, sharpened for mobile gadgets
After buying a smartphone with an OLED display, you have a device with an AMOLED screen in your hands. It uses an active matrix, which is necessary to reduce its size. Passive OLED is used only for large enough household appliances – TVs, monitors, and other panels.
Portable gadgets once used passive OLED displays. We are talking about primitive PMOLED in calculators, old push-button phones and MP3 players. They had an extremely low resolution, which could not be increased. In modern mobile electronics, only active AMOLED.
In comparison with OLED, AMOLED displays are characterized by increased energy efficiency. They do not require an increase in voltage as the resolution increases, so they do not consume excess energy. The most progressive representative of such matrices is Super AMOLED manufactured by Samsung. The maximum brightness of such screens is up to 1750 nits. They use plastic substrates that give the matrices all the advantages of POLED. In Super AMOLED, the touch layer is part of the screen itself, not a separate component, and this makes it possible to achieve a minimum thickness of the mobile device.
The quality of the picture is affected not only by the type of matrix of the screen
It is important to understand that the image quality depends not only on the matrix that is used in the “sandwich” of the display. To maximize detail and other elements of the picture, manufacturers resort to a lot of auxiliary techniques that are also important to consider.
Screen density. It is measured in the number of pixels per square inch and determines the graininess of the picture. Sufficiently clear in the case of OLED is an image with a density of over 350 PPI. To do this, the 6-inch screen should be equipped with a matrix with a resolution of 1920×1080 pixels (1080p).
Refresh rate. It is counted among the times when the image on the screen changes. The higher this value, the smoother any animations seem. Base — 60 Hz. However, recently there are more and more gadgets with a refresh rate of 90, 120 (this is the new standard), 144 and even 240 Hz.
Brightness. From this indicator, measured in cd / m² (nit), modern gadgets, to a greater extent, depends on the possibility of their comfortable use in the sun. To do this, you need a constant value of more than 600 nits. There is also a peak brightness - its value should be taken into account when parsing HDR. Interestingly, brightness is not measured linearly, but logarithmically. That is why 1200 nits are only twice the value of 300 nits. Consequently, the difference between 400 and 500 nits will be minimal, but manufacturers can exaggerate it for purely marketing purposes.