What is the difference between AMOLED and OLED?

Infineon / Mitsubishi / Fuji / Semikron / Eupec / IXYS

What is the difference between AMOLED and OLED?

Posted Date: 2024-02-02

OLED (Organic Light Emitting Diode) organic light emitting diode (device), AMOLED (Active Matrix/Organic Light Emitting Diode) active matrix organic light emitting diode (device) are called the next generation display technology, including Samsung Electronics, Samsung SDI, LG Philips attaches great importance to this new display technology.


AMOLED is still there. Although LEDs are relatively common in daily life, in the screen, the size of each LED is very small, and is divided into three sub-pixel groups of red, green and blue, and then forms different colors, and the arrangement of the sub-pixels The method will also affect the overall display effect. The O in AMOLED stands for Organic, which means "organic". Simply put, a series of organic film materials are used between the positive and negative electrodes to achieve the purpose of emitting light.

AM stands for Active Matrix, which is relative to Passive Matrix and refers to the driving method of each OLED pixel. In Passive Matrix, the control of each pixel is achieved through a complex electrode network to achieve the charge and discharge of a certain pixel. Generally speaking, the control method of Passive Matrix is ​​relatively slow and the control accuracy is slightly lower. Unlike Passive Matrix, Active Matrix installs TFT and capacitive layers on each LED, so that when a certain row or column is energized to activate the intersecting pixel, the capacitive layer in the pixel can be refreshed between two refreshes. Stay charged, allowing for faster and more precise pixel lighting control.


Organic Light-Emitting Diode (OLED) is also called organic laser display and organic light-emitting semiconductor (Organic Electroluminesence Display, OLED). It has a different type of luminescence principle from Liquid Crystal Display (LCD). OLED was discovered in the laboratory by Chinese-American professor Ching W. Tang in 1983, and research on OLED began. OLED display technology has the advantages of self-illumination, wide viewing angle, almost infinitely high contrast, low power consumption, and extremely high response speed. The main advantage of OLED screens is the high degree of controllability of the pixels. Each pixel can be turned on and off independently, resulting in purer blacks and higher contrast. In addition, turning off unnecessary pixels when displaying a picture can also reduce power consumption. At the same time, because there are fewer layers inside the screen module, the light transmittance is also better, which is conducive to achieving higher brightness and wider viewing angles.

OLED screens can be made very thin, making them ideal for mobile devices such as mobile phones. In addition, due to the lack of a hard backlight layer and the maturity of flexible plastic substrates, OLED also has great advantages in flexible screens, creating more possibilities for the form of future mobile devices and even wearable devices.

The difference between the two

AMOLED is OLED, but not the other way around. To put it simply, OLED technology includes PMOLED and AMOLED. PMOLED does not require a TFT backplane (different from the backplane of LCD), but the size cannot be made very large; the size of AMOLED can be made very large. PMOLED mainly existed on early dual-screen mobile phones and was used for small external screens. Current mobile TVs use AMOLED technology.

OLED is an organic light-emitting diode. Its light-emitting material is an organic light-emitting material, which is relative to the LED light-emitting diode. OLED will emit light as long as the correct voltage is applied to the positive and negative terminals. It is the same as a light bulb. If you add a signal to it, it will work.

AMOLED is an active organic light-emitting diode. To work, it not only needs to add a signal, but also needs an additional point source to make the diode reach the working state. At this time, it will light up or off when a signal is given to light up or off. closure. To use an inappropriate analogy, it works like a TV. You connect it to a cable signal, but you can't watch it. You can only watch it if you give it electricity. But if it only provides electricity and no cable signal, there will be no programs to watch.

From a structural point of view, OLED is basically a diode, while AMOLED is a triode or multiple triodes that jointly drive a light-emitting point.

OLED and PMOLED "passive array organic light-emitting diode panels". One is active lighting control and the other is passive lighting control. Our mobile phones generally refer to AMOLED. The so-called OLED is to coat the glass substrate of the screen with a layer of organic material that can conduct electricity and emit light (this material is very expensive), and then AMOLED adds AM technology to the OLED panel for active control.

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