One of the most common questions we get asked regarding TFT performance is related to pixel faults and ‘What makes a good or faulty panel?‘ If you inspect any TFT very closely you will find faults, but this does not mean you have a faulty panel. You will need to consider, firstly, the type of fault that might be exhibited:

• Bright Dot fault: any Red, Green, or Blue pixel stuck in the “On” mode.
• Dark Dot fault: any Red, Green, or Blue pixel stuck in the “Off” mode.
• Dot Position fault: random distance between the dots

Bright Dot – 2 adjacent 

Dark Dot – 2 adjacent

Dark Dot – 3 adjacent

Distance between dots

As a guideline for you, here is the Samsung position as stated on their Cosmetic Outgoing Inspection Specification (TFT LCD : A Grade) where the number = the total number of pixel faults on the panel:  

So, if you are able to detect a pixel failure on your panel, do please consult with your supplier and/or check the technical specification of the individual panel you are utilising, as this failure may not actually constitute a genuine ‘fault’…

Please also remember that TFT panel quality and grade are often directly related to the number of pixel failures that may be allowable by the producer. If you are concerned about the number of pixel failures that are visible to the naked eye, then it may be time to upgrade your panel specification…

For further assistance on your TFT displays, please don’t hesitate to contact us at sales@eurocoincomponents.com.