The concept of "attenuation rate" is a quantitative description of the rate at which the performance of an LCD panel declines over time. It acts like a ruler, measuring the degradation of display quality from sharp and clear to blurry and dim.
The degradation of an LCD panel is not a change in a single indicator, but a comprehensive manifestation across multiple dimensions. First, there is brightness degradation, primarily caused by the decay of the backlight. A new monitor might have a brightness of 300 cd/m², but after three years of use, it might only have 200 cd/m². This percentage and rate of brightness decrease is the brightness degradation rate.
Second, there is color degradation. As polarizers age, color filters fade, and the backlight spectrum changes, the screen's color performance declines. This manifests as a reduction in color gamut coverage (a smaller range of colors that can be displayed) and color accuracy drift (reds are no longer vibrant and pure). For example, some early LCDs, after several years of use, will show a noticeable yellow or blue tint to the entire image.
Furthermore, there is contrast degradation. Because the liquid crystal molecules are not tightly closed, light leakage is aggravated, and black scenes are no longer deep, but rather grayish, thus reducing the contrast of the image. The degradation rate of a panel is a slow and continuous process. High-quality panels are designed with more durable materials (such as long-life LEDs and high-quality polarizers) and employ more reasonable heat dissipation designs to slow down the degradation of various performance characteristics. Therefore, the degradation rate is also an important reference indicator for measuring the intrinsic quality and manufacturing process of an LCD panel. The lower the degradation rate, the longer the "shelf life" of the screen.
