bad pixel

(redirected from Dead pixel)

bad pixel

A defective pixel on an LCD screen. Bad pixels are often transistors that are permanently dead and appear as black dots or permanently energized and show up as white or colored dots ("hot pixels"). These pixel defects usually occur at the time of manufacture. However, if a bad pixel appears after the screen has been in use for some time, it may also be due to a dented or scratched polarizer (see LCD).

Sometimes, it is possible to repair a bad pixel by gently rubbing the screen with a cloth or running a pixel repair over the area for several hours, the latter repetitively flashing colors on and off to attempt to dislodge a stuck pixel.

Does It Matter?
It depends. On an LCD TV, which is displaying motion and is situated several feet from the viewer, dead or lit pixels may not matter. On a computer monitor only two feet away, they may be very annoying, especially if located in the center of the screen. Equipment manufacturers have different policies regarding defective pixels. They typically state that if a certain number of bad pixels exist when the display was purchased, the unit may be returned.


Polarizer Damage
This red pixel is due to damage on the polarizer, which is the screen layer in front of the user (see LCD).







It Can Be Annoying
One bad pixel can be very glaring, depending on where it shows up; witness the single, green pixel on this man's black coat.







Test for Yourself
Dead pixel testers such as Dead Pixel Locator from Astris.com let the user find bad spots by displaying different colors across the entire screen.







Repair Stuck Pixels
Pixel repair programs cycle rapidly through all the colors to possibly dislodge a stuck pixel. There is no guarantee, but if a stuck pixel is annoying, it is worth a try. When this animated GIF is retrieved from Killdeadpixel.com, it is placed over the stuck pixel and left alone for an hour or more.
References in periodicals archive ?
Our particular unit has major touch issues on the panel, while there was even a dead pixel on the display.
Therefore, VisiConsult developed a comprehensive automatic qualification toolbox that determines all parameters through the use of a DR Phantom: Spatial resolution, CNR, SNR and dead pixel map are evaluated through a single click.
In their latest move, they are offering the “0-1 Dead Pixel Guarantee,” this beats the industry standard which is set at 0-5 dead pixels.
had one of the best experiences with Apple's customer service ever--"My iPod Touch has a dead pixel.
Other programmable features include fast global reset, exposure time, frame rate, subsampling, window size, analog and digital gain, horizontal and vertical inversion and dead pixel removal.
Other programmable features include exposure time, frame rate, subsampling, window size, analog and digital gain, horizontal and vertical inversion and dead pixel removal.
Therefore, it pays to verify these policies before making a purchase decision, seeing as even one dead pixel in the centre of the panel can ruin an otherwise perfect display.
3 MegaPixel image sensors significantly reduce the BOM with higher quality by providing on-chip electronic exposure control, programmable color gain, dead pixel removal, low light sensitivity and a flexible interface for wide acceptance and compatibility in the industry.
It ships with an industry leading 5-year standard warranty and a zero dead pixel policy at a low factory-direct price of just US$859.
For example, a single hairline crack on an iPhone is covered in the warranty in the present guide, which wasn't the case with earlier guides; in case you see dead pixels on your display, you can actually go to an Apple repair centre and ask it to be fixed.
Over the weekend there'll also be music from Digbeth Dining Club's finest DJs, as well as Dead Pixels retro gaming and street art.
This type of noise, generated by hot or dead pixels, is typically more prevalent in inexpensive cameras and can be visualized by averaging multiple images from the same camera.