LCD Cosmetic spec

LCD inspection items, test methods and determination specifications, to provide a basis of judgment for IQC, FQC, QA inspectors

Testing environment

Inspection distance: frontal visual distance from the display 30-50cm, each detection screen visual for at least 3-5 seconds, detection angle ± 45 °
Temperature: under normal temperature conditions (23℃-24℃)
brightness: 300-800LUX.

Display area division

Definition of Zone A: The circle with the center of the LCD display and 80% of the vertical height of the LCD display as the radius is called Zone A.
Definition of B zone:All areas other than A zone.

Explanation of defect

There are very many processes in the manufacturing process of the display, and in each process there are defects generated, so the names and specifications of the defects are unified to facilitate management

brightness dot defects

brightness dot defects

Bright dot defects mean that sub-pixels will emit light on any screen, which is not allowed in small and medium-sized products with A+ grades (industrial displays, mobile phone displays, etc.).

darkness dot defects

darkness dot defects

Darkness dot defects means that the sub-pixels will not emit light in any screen, and this kind of defect is not allowed in the A+ grade.

dark spots defects

Dark spot defects refer to dark spots smaller than sub-pixels, which are usually caused by foreign objects.

half brightness pixel defects

bright spot defect

Bright spot defect refers to the non-luminescence phenomenon whose size is smaller than one sub-pixel.

tiny dots defect

tiny spot defects

Tiny spots defects are point-shaped defects distributed in the lcd panel, and there are two kinds of bright spots and dark spots.

line defects

line shape defects

Line shape defects are line-shaped defects inside the LCD panel, which are caused by scratches or line-shaped foreign objects.

upper polarizer defects

upper polarizer defects

Upper polarizer defects are foreign objects in the process of attaching upper polarizers, which can be divided into linear defects and point defects according to their shapes.

lower polarizer defects

lower polarizer defects

The lower polarizer defects are foreign matter in the process of attaching the lower polarizer. Since they are in the lower part of the LCD panel, they cannot be seen clearly and are relatively easy to distinguish.


mura defects

The mura defect refers to the problem of uneven color. There are many types of mura defects, which are usually controlled by means of limited samples (the maximum acceptable to customers).

hot spot

hot spot defects

A hot spot defect refers to an abnormally bright point or an area on the display, and a hot spot is usually caused by backlight leakage.

light leakage

light leakage defects

Light leakage defects refer to the phenomenon of light leakage on the screen caused by abnormal assembly or design, especially in black screens.

liquid crystal leakage

liquid crystal leakage

Defective liquid crystal leakage refers to liquid crystal leakage inside the LCD panel. This defect is usually caused by damage to the LCD panel due to improper use or assembly, resulting in liquid crystal leakage.

Cosmetic spec

defect itemdimensiondegree
brightness dotDistance between two dots≧15mmNot allowedArea B  N≦2Area B N≦5Area A and B N≦8
darkness dotDistance between two dots≧5mmNot allowed N≦3N≦5N≦8
brightness dot+darkness dot Not allowed N≦5N≦8N≦10
two brightness dotDistance between two dots≧15mmNot allowedN≦1N≦2
two darkness dotDistance between two dots≧5mmNot allowedN≦1N≦3
three dots Not allowedNot allowed
dent/damageAverage diameter(mm) D≦0.5Not allowedNot allowed
Stains, spotsW≤0.3,L≤0.5mm;Distance≥5cm Not allowedArea B N≦1Area B N≦2Area B N≦3
Scratches, crush injuriesLength(mm)L<0.5,        Width0.3≦W≦0.5Not allowedNot allowedB区 N≦1
Dark line/light lineLength(mm)L<0.5,        Width0.3≦W≦0.5Not allowedNot allowedN≦1N≦2
Light LeakageΦ≤5mmNot allowedNot allowedN≦1N≦2
abnormal display Not allowedNot allowedNot allowedNot allowed

The above cosmetic spec is the most basic, and the cosmetic spec of Harmony Optoelectronics products will be stricter than it. More than ten years of experience will help us better control product quality and screen defective products, and ensure that the tft display delivered to your company is the best High quality. If there is an unconventional cosmetic spec request, we will fully cooperate and wait for your message at any time!

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