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What is the difference between AMOLED and OLED display technologies?

by HemyobK on Feb 23, 2023

What is the difference between AMOLED and OLED display technologies?

What is AMOLED?

AMOLED stands for Active Matrix Organic Light Emitting Diode. It is a type of display technology used in many modern electronic devices such as smartphones, tablets, and smartwatches.

AMOLED displays are made up of millions of organic light-emitting diodes that emit light in response to an electric current. These diodes are arranged in an active matrix pattern, which allows for precise control over each individual pixel. This results in a high-quality, bright and colorful display with excellent contrast and deep blacks.

Compared to traditional LCD displays, AMOLED displays consume less power because they do not require a separate backlight. Instead, each pixel can be turned on or off independently, reducing power consumption and improving battery life. AMOLED displays are also thinner and lighter than LCD displays, making them ideal for use in portable devices.

What is the difference between AMOLED and OLED?

AMOLED and OLED are two similar display technologies, but there are some key differences between them.

OLED stands for Organic Light Emitting Diode, which is a type of display technology that uses organic compounds to emit light when an electric current is passed through them. OLED displays are made up of millions of tiny, independently lit pixels that can turn on and off individually, resulting in deep blacks, vibrant colors, and excellent contrast.

AMOLED, on the other hand, stands for Active Matrix Organic Light Emitting Diode. It is a type of OLED display that uses a thin-film transistor (TFT) backplane to control the current flowing through each pixel. This allows for more precise control over each pixel, resulting in better image quality and lower power consumption compared to earlier passive-matrix OLED displays.

In general, AMOLED displays are considered to be a more advanced and refined version of OLED displays, as they provide better contrast, more vibrant colors, and consume less power. However, they are also more expensive to produce and can be more difficult to manufacture. OLED displays are generally found in smaller, simpler devices such as wearable technology and smaller smartphone screens, while AMOLED displays are typically used in larger displays such as those found in flagship smartphones and high-end televisions.

What does AM means in AMOLED?

In AMOLED, the "AM" stands for "active matrix". An active matrix display uses a thin film transistor (TFT) backplane to control the voltage and current applied to each individual pixel. This allows for much finer control of the display compared to passive matrix displays, where each row and column of pixels is controlled by shared signals. Active matrix displays, including AMOLED, can have much higher resolutions and better image quality than passive matrix displays.

What is TFT?

TFT stands for Thin-Film Transistor, which is a type of technology used in electronic displays. It is a special type of field-effect transistor that is deposited on a thin film of semiconductor material. TFT technology is commonly used in liquid crystal displays (LCDs) and organic light-emitting diode (OLED) displays.

In a TFT-LCD display, each pixel is controlled by a separate thin-film transistor, which allows for precise and fast voltage control over each individual pixel. This allows for sharper and more detailed images, with better color accuracy and contrast compared to earlier LCD technologies.

Structure of the pixel

Can each pixel of a conventional OLED be turned on independently?

Yes, each pixel of a conventional OLED can be turned on independently, just like in AMOLED displays. In a conventional OLED display, each pixel is made up of three subpixels, one for red, one for green, and one for blue. These subpixels are controlled independently, allowing for precise control over each individual pixel's color and brightness.

However, conventional OLED displays do not use a thin-film transistor (TFT) backplane like AMOLED displays. Instead, they use a passive matrix structure, where each row and column of pixels is controlled by shared signals. This can limit the resolution of the display and result in slower response times compared to an AMOLED display.

In contrast, AMOLED displays use an active matrix structure, where each pixel is controlled by its own thin-film transistor, allowing for much finer control over the display. This results in better image quality and faster response times than conventional OLED displays.

AMOLED vs Traditional OLED in Response Time

The response time of a display refers to how quickly the display can change the color or brightness of a pixel in response to a change in the input signal. A faster response time can result in less motion blur and a smoother overall image.

In general, AMOLED displays have faster response times than traditional OLED displays, due to the use of a thin-film transistor (TFT) backplane. However, the exact difference in response time can vary depending on the specific display and the testing methodology.

Here are some rough estimates of the difference in response time between AMOLED and traditional OLED displays:

  1. Rise time: The rise time refers to the time it takes for a pixel to go from its minimum brightness to its maximum brightness. AMOLED displays typically have a rise time of around 0.1 milliseconds, while traditional OLED displays may have a rise time of 0.3 milliseconds or more.
  2. Fall time: The fall time refers to the time it takes for a pixel to go from its maximum brightness to its minimum brightness. AMOLED displays typically have a fall time of around 0.1 milliseconds, while traditional OLED displays may have a fall time of 0.5 milliseconds or more.
  3. Total response time: The total response time is the sum of the rise time and the fall time. AMOLED displays typically have a total response time of around 0.2 milliseconds or less, while traditional OLED displays may have a total response time of 0.8 milliseconds or more.

It's worth noting that response time is just one aspect of display performance, and that other factors like color accuracy, contrast ratio, and power consumption can also affect the overall image quality.

AMOLED vs Traditional OLED in Contrast

In general, AMOLED displays offer better contrast than traditional OLED displays. This is because AMOLED displays use an active matrix structure with a thin-film transistor (TFT) backplane, which allows for finer control over each individual pixel. As a result, AMOLED displays can achieve deeper blacks and more vibrant colors compared to traditional OLED displays.

The contrast ratio of a display is a measure of the difference between the brightest and darkest parts of an image. A higher contrast ratio indicates a wider range of brightness levels, and can result in a more vivid and realistic image.

Here are some rough estimates of the difference in contrast ratio between AMOLED and traditional OLED displays:

  1. Static contrast ratio: The static contrast ratio is the ratio of the brightest and darkest parts of an image on the display when it is at a fixed, constant level of brightness. AMOLED displays typically have a static contrast ratio of around 100,000:1 or higher, while traditional OLED displays may have a static contrast ratio of 10,000:1 or lower.
  2. Dynamic contrast ratio: The dynamic contrast ratio is the ratio of the brightest and darkest parts of an image on the display when it is varying in brightness level. This is a more accurate measure of the display's ability to reproduce dark scenes with detail. AMOLED displays typically have a dynamic contrast ratio of around 1,000,000:1 or higher, while traditional OLED displays may have a dynamic contrast ratio of 100,000:1 or lower.

It's worth noting that the actual contrast ratio of a display can vary depending on a variety of factors, including the quality of the display panel, the ambient lighting conditions, and the specific image being displayed. Additionally, some manufacturers may use different techniques or technologies to enhance contrast, such as local dimming, which can affect the overall contrast performance of the display.

AMOLED vs Traditional OLED in Refresh Rate

In general, there may not be a significant difference in refresh rate between AMOLED and traditional OLED displays, as both types of displays can support a wide range of refresh rates depending on the specific device and its specifications.

Refresh rate refers to the number of times per second that the display updates the image on the screen. A higher refresh rate can result in a smoother and more responsive user experience, especially when playing games or watching fast-moving content like sports.

However, the refresh rate of a display is determined by the underlying hardware and software, rather than the display technology itself. For example, both AMOLED and traditional OLED displays can support a refresh rate of up to 120Hz, although not all devices may be capable of achieving this maximum rate.

That being said, some newer AMOLED displays may have slightly faster response times than traditional OLED displays, which can result in less motion blur and a smoother overall image. Additionally, some AMOLED displays may use newer technologies like LTPO (low-temperature polycrystalline oxide) to further improve energy efficiency and reduce input lag, which can enhance the user experience when playing games or using other interactive applications.

So what are the advantages of AMOLED over OLED?

Some of the advantages of AMOLED over traditional OLEDs are mentioned above. In fact, AMOLED is ahead of OLED across the board, which is why AMOLED is being used more and more widely nowadays. More of AMOLED's advantages are listed below, including:

  1. Better image quality: AMOLED displays have better image quality than traditional OLED displays, with more vibrant colors, deeper blacks, and improved contrast.
  2. Higher refresh rates: AMOLED displays can support higher refresh rates than traditional OLED displays, resulting in smoother animations and less motion blur.
  3. Lower power consumption: AMOLED displays consume less power than traditional OLED displays, as each individual pixel can be turned on or off independently, resulting in more efficient use of battery power.
  4. Better outdoor visibility: AMOLED displays are more visible in bright sunlight than traditional OLED displays, as they can provide brighter output levels.
  5. Wider viewing angles: AMOLED displays offer wider viewing angles than traditional OLED displays, allowing for easier sharing of content with others.
  6. Thinner and more flexible: AMOLED displays can be made thinner and more flexible than traditional OLED displays, making them ideal for use in curved or flexible screens.

These advantages have made AMOLED displays a popular choice for high-end smartphones, tablets, and other portable electronic devices. However, it's worth noting that AMOLED displays can also be more expensive to produce than traditional OLED displays, and may require more advanced manufacturing techniques.

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