Philips 221T1, 231T1, 201T1SB/00 Defects Proximity of Pixel Defects, Pixel Defect Tolerances

Types of Pixel Defects

Pixel and sub pixel defects appear on the screen in different ways.There are two categories of pixel defects and several types of sub pixel defects within each category.

Bright Dot Defects Bright dot defects appear as pixels or sub pixels that are always lit or 'on'. That is, a bright dot is a sub-pixel that stands out on the screen when the monitor displays a dark pattern.There are the types 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 pixel)

Note

A red or blue bright dot must be more than 50 percent brighter than neighboring dots while a green bright dot is 30 percent brighter than neighboring dots.

Black Dot Defects Black dot defects appear as pixels or sub pixels that are always dark or 'off'. That is, a dark dot is a sub-pixel that stands out on the screen when the monitor displays a light pattern.These are the types of black dot

defects:

Proximity of Pixel Defects

Because pixel and sub pixels defects of the same type that are near to 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 sub pixel defects exceeding

the tolerances listed in the following tables.

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