Kuvapitojen

Kuvapitojen is a Finnish term that translates to "picture holding" or "image retention." It refers to a phenomenon where a static image or a series of images leaves a temporary or permanent impression on a display screen. This is most commonly observed in older display technologies, particularly cathode ray tube (CRT) monitors and some plasma displays.

The mechanism behind kuvapitojen is related to how these displays produce images. In CRTs, an electron beam scans across a phosphor-coated screen. If the same image is displayed for an extended period, the phosphors in that area can become "burned in," meaning they degrade unevenly. This results in a faint ghost of the previous image remaining visible even when a new image is displayed. Similarly, in some plasma displays, pixels can experience uneven wear if subjected to static content for too long, leading to a similar effect.

Modern display technologies like LCD and OLED are generally much less susceptible to kuvapitojen. LCDs use liquid crystals to block or allow light, and these crystals are not prone to degradation from static images. OLED displays use organic light-emitting diodes, which, while they can degrade over time, typically do so more uniformly across the screen, making burn-in less noticeable or a different kind of degradation altogether.

To mitigate kuvapitojen on susceptible displays, users were often advised to avoid displaying static images for long periods, to use screen savers, or to periodically change the content being displayed.