Philips BDL5531EL/00, Service Manual

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BDL5531EL LCD 15
Philips Pixel Defect Policy
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Philips' Flat Panel Displays Pixel Defect Policy
Philips strives to deliver the highest quality products. We use some of the
industry's most advanced manufacturing processes and practice stringent
quality control. However, pixel or sub-pixel defects on the PDP / TFT panels
used in Plasma- & LCD- displays are sometimes unavoidable. No
manufacturer can guarantee that all panels will be free from pixel defects,
but Philips guarantees that any Plasma- & LCD- displays with an
unacceptable number of defects will be repaired during the warranty period
in line with your local guarantee conditions. This notice explains the different
types of pixel defects and defines the acceptable defect level for the
BDL4651VH LCD screen. In order to qualify for repair under warranty, the
number of pixel defects must exceed a certain level which is given in the
reference table. If the LCD screen is within specification a warranty
exchange / claim back will be refused. Additionally, because some types or
combinations of pixel defects are more noticeable than others, Philips sets
even higher quality standards for those.
Pixels and Sub pixels
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A pixel, or picture element, is composed of three sub-pixels in the primary
colors of red, green and blue. Many pixels together form an image. When all
sub-pixels of a pixel are lit, the three colored sub-pixels together appear as a
single white pixel. When all are dark, the three colored sub-pixels together
appear as a single black pixel. Other combinations of lit and dark sub-pixels
appear as single pixels of other colors.
Types of Pixel D Dot Definition
Pixel and sub-pixel defects appear on the screen in different ways. There are
three categories of pixel defects and several types of sub-pixel defects within
each category.
Dot definition = What is a defective "Dot"? : One or more defective,
adjacent sub-pixel are defined as one "dot". The no. of defective sub-pixels
are not relevant to define a defective dot. This means that a defective dot
can consist of one, two or three defective sub-pixels which can be dark or lit.
Bright Dot Defects
Bright dot defects appear as pixels or sub-pixels that are always lit or "on".
These are the examples of bright dot defects:
One lit red, green or
blue sub-pixel Two adjacent lit
sub-pixels:
- Red + Blue = Purple
- Red + Green = Yellow
- Green + Blue = Cyan
(Light Blue) Three adjacent lit
sub-pixels (one white
dot)
Dark Dot Defects
Black dot defects appear as pixels or sub-pixels that are always dark or "off".
These are the examples of black dot defects
One dark dot l Two adjacent dark
dots = 1 pair of dark
dots Two dark dots,
specifications defines
the minimum distance
between dark dots
Proximity of Pixel Defects
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Because pixel and sub-pixels defects of the same type that are nearby one
another may be more noticeable, Philips also specifies tolerances for the
proximity of pixel defects. In the table below you can find specifications
about:
• Allowed amount of adjacent dark dots = (adjacent dark dots =1 pair of dark
dots)
• Minimum distance between dark dots
• Total no. of all defective dots
Pixel Defect Tolerances
In order to qualify for repair due to pixel defects during the warranty period, a
PDP / TFT panel in a Philips Plasma / LCD- display must have pixel or
sub-pixel defects exceeding the tolerances listed in the following table.
BRIGHT DOT EFFECT ACCEPTABLE LEVEL
MODEL BDL5531EL
1 lit sub pixel Max 2
BLACK DOT EFFECT ACCEPTABLE LEVEL
1 dark sub pixel Max 10 (64 gray)
TOTAL DOT DEFECTS OF ALL TYPES Max 12
Note: * 1 or 2 adjacent sub pixel defects = 1 dot defect