Glossary A–ZLetter P
Pixel defect
A pixel defect is a pixel or sub-pixel that does not work properly and stays permanently lit, stays dark or shows the wrong colour.
A distinction is made between bright defects, dark defects and stuck colour points. They are most noticeable on single-colour areas.
On LCD screens, pixel defects usually arise during manufacture. Manufacturers define how many defects of which kind a device may have without being considered faulty; many refer to the defect classes of the ISO 9241-307 standard. On LED walls, individual diodes also fail during operation, for example due to knocks, moisture or ageing; individual points or entire rows then remain dark.
A single pixel defect is often invisible on a large screen from several metres away, but clearly visible on a touchscreen at arm's length. Before buying, operators should check which pixel defect policy the manufacturer applies, test new devices with single-colour test images and keep spare modules for LED walls. A pixel defect is not the same as a burnt-in image.