ISO13406-2 guideline
Introduction
LCD displays are made up of a set number of pixels and each pixel is made from 3 sub-pixels; 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 defaults 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 defaults
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 | Acceptable defects |
| 1024 x 768 | 786,432 | 0.8 | 2 |
| 1280 x 1024 | 1,310,720 | 1.3 | 3 |
| 1600 x 1200 | 1,920,200 | 1.9 | 4 |
| 2048 x 1536 | 3,145,728 | 3.1 | 6 |
| Native resolution | No. of pixels | No. of million pixels | Acceptable defects |
| 1024 x768 | 786,432 | 0.8 | 4 |
| 1280 x 1024 | 1,310,720 | 1.3 | 7 |
| 1600 x 1200 | 1,920,200 | 1.9 | 10 |
| 2048 x 1536 | 3,145,728 | 3.1 | 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 | Acceptable defects |
| 1024 x 768 | 786,432 | 0.8 | 2 |
| 1280 x 1024 | 1,310,720 | 1.3 | 3 |
| 1600 x 1200 | 1,920,200 | 1.9 | 4 |
| 2048 x 1536 | 3,145,728 | 3.1 | 6 |
The above is relevant to Class II LCD panels.
