During the reign of cathode-ray tube (CRT) display devices, ghosting was a common problem reported by owners and users. Also known as image burn-in, it’s characterized by partial or complete images being permanently displayed on the device. It’s frustrating when you discover a ghosted image on your display device, but the good news is that liquid-crystal displays (LCDs) have largely solved this problem.
What Is Ghosting?
The term “ghosting” refers to one or more images being permanently displayed on a TV, computer monitor or other display device. When an image initially appears, it typically does away after a specific amount of time. Ghosting, however, results in images being permanently displayed. After watching a sports game, for example, the scoreboard may become permanently fixed onto the screen. Neither changing the channel nor turning off the display device will make the scoreboard go away. Rather, it becomes a permanent element of the screen.
A CRT suffering from ghosting will still “work,” but it won’t produce a high-quality image. The ghosted image will remain present on screen at all times, and there’s no simple or easy way to remediate the problem.
Ghosting occurs when phosphor compounds within a display device produce significant illumination over a prolonged period. CRTs as well as plasma display devices contain phosphor compounds, which are used as pixels. If some of these phosphor compounds illuminate brighter or for longer than other phosphor compounds, the created image may become permanent.
Why LCDs Are Immune to Ghosting?
Thankfully, LCDS don’t suffer from ghosting. You can leave an LCD running for hours on end without fear of this phenomenon occurring. This is because LCDs don’t contain phosphor compounds. Rather, they use liquid crystals for the pixels, which are illuminated using a backlight.
CRTs have largely been replaced by LCDs, and one of the reasons for the newfound popularity surrounding LCDs is their immunity to ghosting. Because they contain liquid crystals rather phosphor compounds, they don’t suffer from ghosting.
Of course, LCDs offer other advantages over their CRT counterparts. LCDs, for example, typically have a smaller profile. This is apparent if you perform a side-by-side comparison of a 1990s CRT TV to a 2010s LCD TV. The former will likely be larger and heavier than the latter.
Furthermore, LCDs use less energy than CRTs. As a result, they typically cost less to operate. For these reasons and others, LCD has become the world’s leading display technology.
