Viewsonic CDE4302 User Manual

17

Dark spots or patches may occasionally appear on some liquid crystal display (LCD) panels.This is known 

within the industr y as Mura, which is a Japanese term for “unevenness.” It is used to describe an irregular 

pattern or area in which uneven screen uniformity appears under certain conditions. Mura is a result of the 

deterioration of the liquid crystal alignment layer and is most commonly caused by long-term operation under 

high ambient temperatures. It is an industry- wide phenomenon and Mura is not repairable. It is also not 

covered by our warranty terms.
Mura has been around since the introduction of LCD technology and with screens getting bigger and in 

operation 24/7, many displays are running in low light conditions.This all adds to the possibility of Mura 

affecting displays.
HOW TO SPOT MURA
There are many symptoms of Mura and also multiple causes. Several of these are listed below:

•  Impurities or foreign particles in the crystal matrix

•  Uneven distribution of LCD matrix during manufacturing

•  Non-uniform luminance distribution of the backlight

•  Panel assembly induced stress

•  Flaws within the LCD cells

•  Thermal induced stress - high temperature operation over long periods of time

HOW TO AVOID MURA
Although we can not guarantee the complete eradication of Mura every time, in general the appearance of 

Mura can be minimized by these methods:

•  Lower the backlight brightness

•  Use a screen saver

•  Reduce the ambient temperature around the unit

Image sticking judgment standard  

Mosaic (8×6)

1Hr

• isappear within 10Min’
• ok level: under 2 leve