Screen Pixel Types

Many pixels combine to create images on screens.

A pixel is the smallest screen element on a display device, such as a digital camera screen, monitor or television, which forms the images displayed on a screen. The word “pixel” is a combination of “pix” for “pictures” and “el” for “picture element.” A pixel is can be either liquid crystal or phosphor elements that are energized at different intensity levels to create a range of colors.

Subpixel

Each pixel is further divided into a subpixel in liquid crystal display screens. LCD subpixels use liquid in conjunction with backlighting in order to display images onto a screen. The amount of liquid varies, allowing different amounts of light through to its filters. A subpixel can appear to be red, green and blue with varying levels of brightness. Screen panels also include tiny transistors that transmit current to each pixel. If a transistor shorts, a dead pixel is formed.

Megapixel

A megapixel, also known as MP or Mpx, is a term used to represent 1 million pixels. A megapixel is commonly used to express the image sensor on a digital camera or its digital display. For example, many camera specifications display information like “8 megapixels.” The camera’s sensor elements are called pixels, and the N-megapixel information provides how much of the image could be scanned before looking fuzzy.

Dead Pixel

A dead pixel can look like a square or a small dot on your screen that remains the same color no matter what the rest of the picture looks like. It can appear to be white, black or one color. Dead pixels often have uneven or no liquid behind them. They are less likely to be repaired, but there are rare instances where a black pixel is simply stuck in a certain position. If your computer monitor has a dead pixel, there are numerous online tests that can determine the cause of the problem and provide instructions on how to resolve the issue.

Stuck Pixel

Pixel problems are the result of the LCD screen not functioning properly. Unlike a dead pixel, a stuck pixel has a better chance of being fixed. A stuck pixel will remain white or any one of the three colors (red, green and blue) that a sub-pixel can form. A stuck pixel also occurs when one or all of the subpixels have failed.

References

• PC Mag: Pixel Definition
• IS&T/SPIE Symposium on Electronic Imaging: A Brief History of Pixel
• PC Mag: LCD Subpixels

Resources

• Microsoft: Dead Pixel Checker