AMOLED Dispalay Technology

Active-matrix OLED (Active-matrix organic light-emitting diode or AMOLED) is a display technology for use in mobile devices such as mobile phones. OLED describes a specific type of thin display technology which doesn't require a backlight and Active-Matrix refers to the technology behind the addressing of pixels. AMOLED technology continues to make progress towards low-power and low-cost large size (e.g. 40-inch) for applications such as TV



Technical explanation

An active-matrix OLED (AMOLED) display consists of OLED pixels that have been deposited or integrated onto a thin film transistor (TFT) array to form a matrix of pixels that generate light upon electrical activation, which functions as a series of switches to control the current flowing to each of the pixels.

Typically, this continuous current flow is controlled by at least two TFTs at each pixel, one to start and stop the charging of a storage capacitor and the second to provide a voltage source at the level needed to create a constant current to the pixel and eliminating need for the very high currents required for passive OLED matrix operation

Characteristics
Active-matrix OLED displays provide higher refresh rate than their passive-matrix OLED counterparts, and they consume significantly less power. This advantage makes active-matrix OLEDs well suited for portable electronics, where power consumption is critical to battery life. The amount of power the display consumes varies significantly depending on the color and brightness shown. "For example, our measurement shows that a commercial QVGA OLED display consumes 3 and 0.7 Watts showing black text on a white background and white text on a black background, respectively.

Advantages

OLED displays fabricated on flexible plastic substrates have the following advantages:^[5]

• Thin, lightweight and rugged
• Lower-power, superior image quality, and low cost compared to current LCDs
• Rollable display to tuck away when not in use

Disadvantages
AMOLED displays are prone to material degradation. However technology has been invented to circumvent this problem.^[6][7][8] Whether these mechanisms have been implemented in current applications of AMOLED displays is unknown, as are potential effects on power consumption.