ISO 13406-2 is an ISO standard, with the full title "Ergonomic requirements for work with visual displays based on flat panels -- Part 2: Ergonomic requirements for flat panel displays". It is best known to end consumers for defining a series of flat-panel display "classes" with different numbers of permitted defects (or "dead pixels"). ISO 13406-2 also provides a classification of Viewing Direction Range Classes and Reflection Classes.

As part of an ISO standard, the classes are guidelines, and not mandatory. Where implemented, the interpretation of the standard by the panel or end product manufacturer and effects in terms of labeling of products, what class of panel is used, etc., can vary. Most flat-panel vendors use this standard as the excuse for not accepting returns of defective flat-panels. 

The standard lists four classes of devices, where a device of a specified class may contain a certain maximum number of defective pixels. Three distinct types of defective pixels are described:

type 1 = a hot pixel (always on, being colour white)

type 2 = a dead pixel (always off, meaning black)

type 3 = a stuck pixel (one or more sub-pixels (red, blue or green) are always on or always off)

The table below shows the maximum number of allowed defects (per type) per 1 million pixels.

type 1: 2 pcs

type 2: 2 pcs

type 3: 5 pcs

Cluster with more than one type 1 or type 2 faults: 0 pcs

Cluster of type 3 faults: 2 pcs

As of 2007, most manufacturers specify their products as Pixel Fault Class II. In case you wish to clarify pixel warranty please contact us.