Kylmäkatodivalaisimet

Kylmäkatodivalaisimet, often referred to as cold cathode fluorescent lamps (CCFLs), are a type of gas-discharge lamp that produces light by exciting a fluorescent coating using a cold cathode. Unlike hot cathode lamps, which require a heated filament to initiate the discharge, CCFLs operate at lower temperatures. They consist of a sealed glass tube filled with an inert gas, such as neon or argon, and a small amount of mercury. Electrodes are placed at each end of the tube. When a high voltage is applied across the electrodes, it ionizes the gas, creating a plasma. This plasma emits ultraviolet (UV) light, which then strikes a phosphor coating on the inside of the tube, causing it to fluoresce and emit visible light.

CCFLs were widely used as backlights for liquid crystal displays (LCDs) in monitors, televisions, and laptops before being largely superseded by light-emitting diodes (LEDs). They offer advantages such as a wide dimming range, good color reproduction, and relatively long lifespan. However, their energy efficiency is lower than that of LEDs, and they require a high-voltage inverter to operate, adding complexity and cost to the system. CCFLs are also sensitive to temperature fluctuations, which can affect their performance and lifespan. While their use in displays has declined, CCFLs can still be found in some specialized lighting applications, such as UV curing, germicidal lamps, and decorative lighting.