Pronunciation: [fˈɒsfə skɹˈiːn] (IPA) 
The spelling of "phosphor screen" can be a bit tricky due to the silent "h" in phosphor. The word is spelled with the letter "p" followed by the letters "h-o-s-p-h-o-r." The "ph" in phosphor is pronounced as an "f" sound, not a "p" sound. So the correct pronunciation using IPA phonetic transcription is /ˈfɒsfə(r) skriːn/. This term refers to a type of screen used in electronics that emits light when struck by electrons.
A phosphor screen, also known as a fluorescent screen, is a device commonly used in various imaging systems and display technologies. It consists of a thin layer or coating of phosphor material that emits visible light when excited by electromagnetic radiation, typically high-energy electrons or ultraviolet (UV) light.
The phosphor screen works based on the phenomenon of phosphorescence, which is the ability of certain materials to absorb energy and re-emit it as light over an extended period. When electrons or UV photons strike the phosphor surface, they transfer energy to the atoms within the material, causing the electrons to jump to higher energy levels. As these electrons transition back to lower energy levels, they release the excess energy as visible light.
Phosphor screens find diverse applications, most notably in cathode ray tubes (CRTs), where they are used as the final layer that produces the visible image. In CRT displays, an electron beam scans across the phosphor-coated screen, exciting the phosphor particles to emit light and generate the images visible to the viewer. Additionally, phosphor screens are also utilized in various technologies such as X-ray imaging, night vision devices, and medical imaging systems.
The characteristics of a phosphor screen, such as its brightness, color, persistence, and decay time, can vary depending on the specific phosphor material used. Different phosphors may emit light of different wavelengths, allowing for the creation of color displays. Advances in phosphor technology have led to the development of more efficient and higher-quality screens, enabling them to be widely implemented in modern display technologies.
The word "phosphor" has its origins in the Greek language. It is derived from the Greek word "phosphoros", which means "light-bringing" or "light-bearing".
The term "screen" originates from the Middle Dutch word "skerm" or the Middle Low German word "scherm", both meaning "something that protects or divides". It later evolved in English with the same meaning. In the context of display technology, a screen refers to a surface on which images or information are displayed.
Therefore, the term "phosphor screen" combines the Greek word "phosphor" which represents light, with the English word "screen", which refers to a display surface. It is commonly used to describe the coating on the inside of a cathode ray tube (CRT) or other similar display devices that emit light when excited by electrons.
