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The following page sets out laptop screen industry standards with regards to dead pixels and provides background information regarding LCD screen technology.
Dead Pixels
LCD (liquid crystal display) screens come in various sizes and resolutions. Resolution is defined as the number of pixels or small dots that make up an LCD screen. The pixel is the smallest unit that makes up an image. Most screens sold today are TFT active matrix LCD screens. TFT active matrix is a technology in which each pixel has a transistor attached to it to control the backlight shining through. Each pixel is made up of 3 sub-pixels (red, green and blue) with each having its own transistor. Each of these pixels turns on and off and filters light through colored sub-pixels which results in an image.
Occasionally, these individual transistors will short or remain open resulting in a dead pixel. There are two occurrences which define a dead pixel: a "lit" pixel, which appears as one of several randomly placed white, red, blue and/or green pixel elements on a dark background; or a "missing" pixel, which appears as a black dot on light-colored background.
Considering the number of pixels contained in an LCD panel, the defective rate should dead pixels be present is usually quite minute. For a typical laptop screen, a 14.1" screen with XGA resolution (1024 x 768 pixels), has a total of 2,359,296 red, green and blue pixels (1024 x 768 x 3). So a screen with 5 dead sub-pixels has a defective rate equal to 0.0002%.
What is the industry standard regarding dead pixels?
There is no one clear industry standard regarding an acceptable level of dead pixels. Each LCD screen manufacturer and each laptop maker have their own dead pixel standards. And unfortunately, in most cases the end-user is not aware of their respective laptop brand's dead pixel policy until after a laptop is purchased and dead pixels are noticed. ScreenTek, however, would rather take the approach of educating our customers about industry standards and being proactive in informing our customers about our dead pixel policy.
The following table is a summary of various laptop brands' and screen manufacturers' dead pixel policies. The data provided below is subject to change by the laptop makers and LCD manufacturers and vary depending on size, resolution and model. The amounts represent in general the number of dead pixels required for screen replacement.
Laptop Brand / OEM |
Bright Dots |
Dark Dots |
Total Dots |
Dell |
7 |
7 |
7 |
IBM |
5 to 11 |
5 to 16 |
9 to 16 |
HP/Compaq |
7 |
7 |
9 |
LG.Philips |
6 |
6 |
10 |
Sharp |
7 |
7 |
N/A |
ScreenTek |
3 |
3 |
3 |
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