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
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 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.
bright spot defect
Bright spot defect refers to the non-luminescence phenomenon whose size is smaller than one sub-pixel.
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 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 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
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 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 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
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 item | dimension | degree | ||||||
| A+ | A（A） | B（A-） | C（B） | |||||
| brightness dot | Distance between two dots≧15mm | Not allowed | Area B N≦2 | Area B N≦5 | Area A and B N≦8 | |||
| darkness dot | Distance between two dots≧5mm | Not allowed | N≦3 | N≦5 | N≦8 | |||
| brightness dot+darkness dot | Not allowed | N≦5 | N≦8 | N≦10 | ||||
| two brightness dot | Distance between two dots≧15mm | Not allowed | N≦1 | N≦2 | ||||
| two darkness dot | Distance between two dots≧5mm | Not allowed | N≦1 | N≦3 | ||||
| three dots | Not allowed | Not allowed | ||||||
| dent/damage | Average diameter(mm) D≦0.5 | Not allowed | Not allowed | |||||
| Stains, spots | W≤0.3，L≤0.5mm；Distance≥5cm | Not allowed | Area B N≦1 | Area B N≦2 | Area B N≦3 | |||
| Scratches, crush injuries | Length(mm)L<0.5， Width0.3≦W≦0.5 | Not allowed | Not allowed | B区 N≦1 | ||||
| Dark line/light line | Length(mm)L<0.5， Width0.3≦W≦0.5 | Not allowed | Not allowed | N≦1 | N≦2 | |||
| Light Leakage | Φ≤5mm | Not allowed | Not allowed | N≦1 | N≦2 | |||
| abnormal display | Not allowed | Not allowed | Not allowed | Not 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!
