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Our Dead Pixel Policy
Ref: 437
Introduction
LCD displays are made up of a set number of pixels and each pixel is
made from 3 subpixels; one Red, one Blue and one Green. Every sub-pixel
is addressed by its own transistor and so the manufacture of a glass
substrate is very complex. Due to the nature of the manufacturing
process, occasional defects can occur. Pixel defects or failures
cannot be fixed or repaired and can happen at any stage in the LCD’s
life.
To regulate the acceptability of defects and to
protect the end user, ISO have created a standard for manufacturers
to follow. ISO 13406-2 recommends how many defects are acceptable
in a display before it should be replaced, within the terms & conditions
of warranty. All reputable manufacturers conform to and support the
ISO 13406-2 standard.
Pixel defects
The table below shows the allowable number of malfunctioning pixels
that are acceptable, depending on the native resolution of the LCD
and allowing for 2 malfunctioning pixels per million pixels.
| Native Resolution |
No. of Pixels |
No. of Million Pixels |
Allowable Defects |
| 1024 x 768 |
786,432 |
0.79 |
2 |
| 1280 x 1024 |
1,310,720 |
1.31 |
3 |
| 1600 x 1200 |
1,920,000 |
1.92 |
4 |
| 2048 x 1536 |
3,145,728 |
3.15 |
6 |
The table below shows the allowable number of malfunctioning
sub-pixels that are acceptable, depending on the native resolution
of the LCD and allowing for 5 malfunctioning sub-pixels per million
pixels.
| Native Resolution |
No. of Pixels |
No. of Million Pixels |
Allowable Defects |
| 1024 x 768 |
786,432 |
0.79 |
4 |
| 1280 x 1024 |
1,310,720 |
1.31 |
7 |
| 1600 x 1200 |
1,920,000 |
1.92 |
10 |
| 2048 x 1536 |
3,145,728 |
3.15 |
16 |
The table below shows the allowable number of malfunctioning
sub-pixels that are acceptable within a 5 x 5 block of pixels, depending
on the native resolution and allowing for 2 malfunctioning sub-pixels
within a 5 x 5 block, per million pixels.
| Native Resolution |
No. of Pixels |
No. of Million Pixels |
Allowable Sub-pixel
Defects Within 5 x 5 Block |
| 1024 x 768 |
786,432 |
0.79 |
4 |
| 1280 x 1024 |
1,310,720 |
1.31 |
7 |
| 1600 x 1200 |
1,920,000 |
1.92 |
10 |
| 2048 x 1536 |
3,145,728 |
3.15 |
16 |
The above is relevant to Class II LCD panels. |
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