In today’s digital world, displays with different technologies and panels are sold in the market, and each display can greatly affect the satisfactory user experience depending on the technology and panel and the features it offers.
*This article was written by Siamak Ahadi on 22nd of 2014 and updated by Shabnam Towai on 12th of December 1401.*
In fact, like computers, monitors also have complex technologies that, if you know about them, you can get the best product at a reasonable price depending on your needs and usage. Since their introduction to the field of electronics, display technology has been accompanied by many changes and improvements, and today buyers are faced with many choices.
What is an OLED panel?
Currently, the technology used in the OLED panel is known as the most advanced and complete display manufacturing technology in the world and uses very small organic LEDs that emit colored light when receiving electricity. To create an image on the screen, we only need red, green and blue lights, and the OLED panel or Organic Light Emitting Diode produces these lights by sending an electrical signal to each individual pixel, and no longer needs a background light. .
Millions of small LEDs in OLED displays can produce a specific color independently using radiation technology. By turning on and off, these LEDs display black in the deepest possible state and produce a lot of contrast.
The ability to produce black color in each display is one of the important determining factors in their image quality, and OLEDs can display black color better than any other display with the help of their manufacturing technology. In addition, OLED panels offer wide viewing angles with impressive quality, and their response time is almost instantaneous.
Advantages of OLED panel
Compared to other existing panels, OLED panels are thinner and lighter and offer better performance. Each pixel by turning on and off can create absolute black and as a result, Impressive clarity to display This is one of the unique characteristics of OLEDs, and the reason for this is the independent conduction of each pixel separately.
Another advantage of OLED panels Not needing backlight which causes the thickness of the panel to be greatly reduced and 4 to 7 mm displays based on this technology are produced which are very light.
OLEDs, due to the very good control they have on each pixel, Fantastic contrast and black in these displays is very deep and white is also at a satisfactory level. With these interpretations, it is hard not to get excited about OLED technology; Because it brings to Armaghan all the features of a dream display, including amazing clarity and incredible thinness and low energy consumption.
Gamers and movie watchers will love OLED. These displays Much faster response time They have LCDs. In some conditions, OLEDs can be up to 1,000 times faster than conventional LED LCDs on the market, making it very attractive to watch action movies or sports or video games on OLEDs. Very fast response time means that there are no problems such as dimming of the scene in fast images in OLED.
Disadvantages of OLED panel
Despite all the capabilities of OLED panels, these panels are not perfect either. In OLEDs, the risk Burn-in Or Permanent image burn There is; Especially when the elements remain fixed on the screen for a long time. In some monitors, if the image is displayed on the screen for a long time (for example, several days), the image remains on the screen and does not resolve itself. to this phenomenon Image burn Or Screen burn Called.
Burn-in occurs when some pixels are used more than other pixels and their color becomes slightly different from the color of other pixels around. In such a situation, the affected pixels cannot change color. being developed And Very high price And low brightness OLEDs are among the other disadvantages of panels, which are expected to be resolved in the not-so-distant future.
The difference between LCD and OLED
LCD uses a color filter and liquid crystal on the background light, and plasma also uses ultraviolet light produced by gas packets that excite red, blue, and green color phosphors. The most important advantage of OLEDs is that each pixel emits light directly.
On the other hand, in LCD panels, the background light is provided by LED or fluorescent lamps. In fact, OLED panels can change the state of individual pixels from on to off; For this reason, it is no longer seen around the lighting objects like LCD panels, and the black color is deeper and more uniform.
The difference between LED and OLED
LED panel or equipped with light-emitting diodes (Light-Emitting Diode Display) is a type of light flat panel with low depth, and in fact, it is considered a type of LCD panel that has a similar structure, but a different technology for emitting background light with LCD. In LEDs, instead of fluorescent lamps, LED lighting systems are used to produce light, and instead of integrated backlight systems, LED lamps are used to illuminate pixels; Therefore, the full name of this type of display is LED LCD, which is called LED for short.
LED panels consume less energy than LCD and plasma; But they are still not comparable to OLEDs. In OLEDs, materials are used that are made of organic carbon and produce light by passing current. If we want to explain more simply, LEDs are placed together like small light bulbs; While OLEDs are surfaces that emit light.
Different types of OLED panels
Active matrix, passive matrix, transparent, top emission, flexible and white are different types of OLED panels, each offering different types of applications.
PMOLED (passive matrix)
PMOLED or passive-matrix OLED has cathode strips and organic layers and anode strips, where the anode strips are placed perpendicular to the cathode strips. The junction of the cathode and anode forms the pixels where light is emitted. External circuitry applies current to selected anode and cathode strips and determines which pixels are on and which pixels are off.
PMOLED panels are easy to make; But they consume more energy than other types of OLED, which is mainly due to the power required for the external circuit. PMOLEDs are efficient for displaying text content and are used for small displays such as cell phone displays, portable devices, and MP3 players. Of course, even with the external circuit, passive matrix OLEDs still consume less energy compared to LCDs.
AMOLED (active matrix)
AMOLED or active-matrix OLED has full layers of cathode and organic molecules and anode, with the anode layer placed on a thin-film transistor (TFT) array. This array forms a matrix that determines whether each pixel is on or off. TFT array requires less energy from external circuits, AMOLED panels consume little energy; Therefore, they are more efficient for larger displays. In addition, AMOLEDs have a high refresh rate and are suitable for video playback.
The best applications of AMOLED panels can be introduced as computer monitors and large TVs and electronic or advertising boards.
Transparent OLEDs have only transparent components (substrate, cathode and anode) and when they are turned off, up to 85% of the back image can be seen. Transparent OLED panels can be of the active or passive matrix type, and when turned on, light can pass in either direction.
This technology can be used for head-up displays or displays that display information in front of the viewer’s line of sight. Head-up displays were originally designed for military aircraft; But today they are used in commercial planes, tanks and other devices such as cars.
OLED emission from above
Top-emitting OLEDs are produced either in opaque or reflective type and are suitable for active matrix design. This technology may be used in smart cards with displays or pagers.
Foldable OLEDs have substrates made of highly flexible metal or plastic foils. These panels are very light and durable, and their use in devices such as phones and portable devices can reduce the risk of breakage. Foldable OLED panels could potentially be attached to fabric to produce smart clothing with a computer chip and GPS receiver.
White LEDs emit white light that is brighter, more uniform and more efficient than the light emitted by fluorescent lamps. In this panel, elements of red, green and blue colors are combined and when current passes through them, these elements produce white light. This white light passes through a color filter to produce red, green, and blue pixel elements.
White OLED technology seems a bit strange at first glance. Why, when we have three colors, do we have to make white light by combining them and again by passing it through a special color filter? The problem is that this technology has several advantages. The white light produced in this method is more stable and less likely to change color. According to LG officials, this method has a lower production cost. Also, in WOLED it is easier to produce displays of different sizes.
Which companies produce OLED TVs?
In 2012, LG and Samsung introduced their OLED panels. Although Samsung was one of the prominent producers of OLEDs, it followed the production of these displays only in the dimensions of phones and tablets. The Korean tech giant launched a new production line of OLEDs in 2022, using Samsung Display panels. Until now, LG was the only manufacturer of OLED panels for TVs.
Apple also started using OLED panels in its watches in 2015 and in its laptops in 2016 with the introduction of the touch bar in the MacBook Pro. In 2017, on the 10th anniversary of the iPhone, the company introduced the X model with an optimized OLED display.
Can OLED displays display 3D images?
Yes, both types of 3D technology, including active and passive, can be implemented in OLED TVs. LG uses passive 3D technology in its TVs. To learn about this technology and its difference with active technology, the articles “3D at home; Read “Playback Technologies (Part I)” and “Everything you need to know about 3D TV”.