Pixel Defect Policy - Philips 190S5CG/00 Service Manual

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190S5 LCD
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Philips' Flat Panel Monitors 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 subpixel defects on the TFT
LCD panels used in flat panel monitors are sometimes unavoidable.
No manufacturer can guarantee that all panels will be free from pixel
defects, but Philips guarantees that any monitor with an unacceptable
number of defects will be repaired or replaced under warranty.
This notice explains the different types of pixel defects and defines
acceptable defect levels for each type. In order to qualify for repair or
replacement under warranty, the number of pixel defects on a TFT LCD
panel must exceed these acceptable levels.
For example, no more than 0.0004% of the subpixels on a 15" XGA
monitor may be defective. Additionally, because some types or
combinations of pixel defects are more noticeable than others, Philips
sets even higher quality standards for those.
Pixels and Subpixels
A pixel, or picture element, is composed of three subpixels in the
primary colors of red, green and blue. Many pixels together form an
image. When all subpixels of a pixel are lit, the three colored subpixels
together appear as a single white pixel. When all are dark, the three
colored subpixels together appear as a single black pixel.
Other combinations of lit and dark subpixels appear as single pixels of
other colors.
Types of Pixel Defects
Pixel and subpixel defects appear on the screen in different ways.
There are two categories of pixel defects and several types of subpixel
defects within each category.
Bright Dot Defects Bright dot defects appear as pixels or subpixels that
are always lit or "on".
These are the types of bright dot defects:
One lit red, green or blue subpixel
Two adjacent lit subpixels:
- Red + Blue = Purple
- Red + Green = Yellow
- Green + Blue = Cyan (Light Blue)
Three adjacent lit subpixels
(one white pixel)

Pixel Defect Policy

Black Dot Defects
Black dot defects appear as pixels or subpixels that are always dark or
"off".
These are the types of black dot defects:
One dark subpixel
Two or three adjacent dark subpixels
Proximity of Pixel Defects
Because pixel and subpixels defects of the same type that are nearby
one another may be more noticeable, Philips also specifies tolerances
for the proximity of pixel defects.
Pixel Defect Tolerances
In order to qualify for repair or replacement due to pixel defects during
the warranty period, a TFT LCD panel in a Philips flat panel monitor
must have pixel or subpixel defects exceeding the tolerances listed in
the following tables.