It wasn’t long ago when cathode-ray tube (CRT) dominated the display market. In the past, most displays — televisions, computer monitors, etc. — used CRT technology. CRT, in fact, has become synonymous with old-style displays. Like many other display technologies, though, CRT has since become a thing of the past. To learn more about CRT displays and why they are no longer around, keep reading.

What Is CRT Display?

A CRT display is a type of display device that uses one or more electron beams to produce images. They feature a layer of phosphor compounds, which serves as the pixel layer. To produce images, CRTs strike the phosphor compounds with electrons. Electrons essentially excite the phosphor compounds, causing them to illuminate so that an image is produced.

CRT displays are also known as picture tubes. This is because their electron gun or guns are placed in a vacuum tube. The vacuum tube allows the electron gun or guns to shoot the phosphor compounds from behind.

Why CRT Isn’t Used for Displays Today

You typically won’t find any newly manufactured displays featuring CRT technology. Around the turn of the 21st century, alternative display technologies emerged, specifically flat-panel display technologies. As manufacturers gradually transitioned to these new flat-panel display technologies, CRT displays began to fade.

2008 was a turning point for the industry, as it marked the first time that flat-panel displays outsold their CRT counterparts. Today, most displays use a flat-panel technology, such as liquid-crystal display (LCD) or one of its variants. So, why aren’t CRT displays still being produced?

One of the reasons why CRT isn’t used for modern-day displays involves its size. CRT displays are bulkier and larger than flat-panel displays. This is because they contain a vacuum tube. Flat-panel displays don’t need a vacuum tube because they don’t have any electron guns. As a result, they are slimmer and smaller than CRT displays.

CRT displays are also prone to screen burn-in. Also known as image burn, screen burn-in is a phenomenon in which part of an image is permanently displayed on the screen. Even when the display is turned off, the affected part of the image will be visible.

In the past, burn-in was common because most displays used CRT technology. When this problem occurred, the CRT display would have to be repaired or replaced. Flat-panel displays, however, are protected against screen burn-in. They don’t contain phosphor compounds, so they are immune to screen burn-in.