Panel Inspection Specification - BenQ GL2040 Service Manual

5.2 Panel Inspection Specification

1. Description
These inspection standards shall be applied to LCD Module supplied by CHI MEI Optoelectronics Corporation.
2. The environmental condition of inspection
The environmental condition and visual inspection shall be conducted as below.
(1) Ambient temperature: 15~25 ℃
(2) Humidity: 25~75 %RH
(3) External appearance inspection shall be conducted by using a single 20W fluorescent lamp or equivalent
illumination.
(4) Panel visual inspection on the operation condition for cosmetic shall be conducted at the distance 35cm or
more between the LCD module and eyes of inspector. And, the viewing angle shall be 90 degree to the front
surface of display panel.
Ambient Illumination: 400 ~ 600 Lux for external appearance inspection
Ambient Illumination: 100 ~ 200 Lux for light on inspection
(5) Using method for ND Filter
When using ND Filter for judging Mura, placing ND Filter near Mura defect and get close to the surface of LCD
Panel (its distance shall be 1~2cm between the surface of panel and ND Filter.) Don't touch the surface of
polarizer to avoid scratching polarizer, and then move to the defect position to judge mura by view angle 90
degree (The viewing angle shall be 90 degree to the right top of Mura defect with panel.)
3. Classification of defects
Defects are classified two types, major defect and minor defect according to the defect. And, the definition of
defects is classified as below.
(1) Major defect
Any defect may result in functional failure, or reduce the usability of product for its purpose. For example,
electrical failure, deformation and etc.
(2) Minor defect
A defect that is not to reduce the usability of product for its intended purpose and un-uniformity, dot defect and
etc.
The criteria on major and/or minor judgment will be according with the classification of defects.
4. Inspection Criteria
(1) Definition of dot defect induced from the panel inside a) the definition of dot: The size of a defective dot over
1/2 of whole dot is regarded as one defective dot.
b) Bright dot: Dots appear bright and unchanged in size in which module is displaying under black pattern.
c) Dark dot: Dots appear dark and unchanged in size in which module is displaying under pure red, green, blue
picture.
d) 2 dot adjacent = 1pair = 2 dots
Picture:
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