**Introduction to AMOLED**
AMOLED, short for Active Matrix Organic Light-Emitting Diode, is a type of display technology that uses organic compounds to emit light when an electric current is applied. Unlike traditional liquid crystal displays (LCDs), which require a backlight, AMOLED screens are self-illuminating, allowing for deeper blacks, higher contrast ratios, and wider viewing angles. This makes them ideal for high-quality visual experiences in various electronic devices.
AMOLED combines two key technologies: OLED (Organic Light-Emitting Diode) and AM (Active Matrix). The OLED part refers to the thin-film display technology where organic materials emit light when electrically stimulated. The AM part refers to the pixel addressing system that allows precise control over each pixel. Since 2011, AMOLED has been widely used in mobile phones, tablets, and media players, with ongoing improvements aimed at reducing power consumption, lowering costs, and increasing screen sizes.
In an AMOLED display, the organic molecules are excited by an electrical current, causing them to emit light. Each pixel acts as a switch, controlling the flow of current to produce the desired image. The TFT (Thin-Film Transistor) backplane is crucial for this process, enabling efficient and accurate pixel control. Currently, two main types of TFT backplanes are used in AMOLED: polysilicon and amorphous silicon, both of which contribute to the performance and efficiency of the display.
One of the major advantages of AMOLED is its ability to produce vivid colors and deep blacks without the need for a backlight. It also offers faster response times and lower power consumption compared to passive OLEDs, making it suitable for portable devices where battery life is important. However, one drawback is that AMOLED screens can be harder to view in direct sunlight due to their reflective nature.
**AMOLED Is Not Backlit**
Unlike LCDs, which rely on a backlight to illuminate the screen, AMOLED displays generate their own light at the pixel level. This self-emissive property allows for more energy-efficient operation, especially when displaying dark content. However, because of the way pixels are arranged, the effective resolution of AMOLED screens may appear lower than the stated resolution, resulting in less detailed images at the same resolution compared to some LCDs.
The fast response time and low power usage make AMOLED an excellent choice for modern smartphones and wearable devices. That said, users should be mindful of the background color settings. If the screen is often filled with bright or light-colored backgrounds, the power consumption can increase significantly, sometimes exceeding that of traditional LCDs.
**Basic Principle of AMOLED**
1. **Light Emission Principle**
The basic structure of an OLED consists of an anode, a cathode, and an organic functional layer sandwiched between them. This layer typically includes a hole transport layer, an electron transport layer, and an organic light-emitting layer. When voltage is applied, electrons and holes are injected into the respective layers and recombine in the emitting layer, forming excitons. These excitons then decay and emit photons, producing visible light.
2. **Drive Mode**
There are two main drive modes for OLEDs: Passive Matrix (PMOLED) and Active Matrix (AMOLED). PMOLEDs are simpler in design, with each pixel controlled individually, but they are limited in size and resolution due to the large number of control lines required. In contrast, AMOLED uses a driver circuit to control the pixels, reducing the number of control lines and enabling high-resolution, low-power, and fast-response displays. As a result, AMOLED has become the dominant technology in modern OLED displays.
As AMOLED technology advances, the driving circuits have become smaller, but the electrical performance demands have increased. Traditional amorphous silicon technology struggles to meet these new requirements, leading to the adoption of Low Temperature Polysilicon (LTPS). LTPS improves carrier mobility and reduces defects, offering better electrical properties and making it ideal for next-generation AMOLED displays.
**AMOLED Device Structure**
The structure of LTPS-AMOLED shares similarities with LCDs in terms of the driving circuit, but it differs in the absence of a backlight. This makes AMOLED displays thinner, lighter, and more energy-efficient, especially when showing dark scenes. Additionally, AMOLED's self-illumination feature allows for significant power savings compared to LCDs, which constantly consume power for the backlight.
AMOLED displays come in two main configurations: bottom-emitting and top-emitting. Top-emitting structures allow light to pass through the driving circuit, resulting in a higher aperture ratio and better performance in high-resolution applications. As a result, top-emitting AMOLED has become increasingly popular in advanced display technologies.
Interface Drivers Receivers Transceivers
Shenzhen Kaixuanye Technology Co., Ltd. , https://www.icoilne.com