How do cathode-ray screens in older televisions and oscilloscopes use cathodoluminescence?

Cathode-ray screens in older televisions and oscilloscopes utilize cathodoluminescence by directing a focused stream of high-speed electrons—historically referred to as cathode rays—onto a screen coated with phosphor materials.21

When these accelerated electrons strike the phosphor coating, they transfer energy to the molecules, causing them to emit light. In monochrome displays, this process typically involves a mixture of phosphors that glow to produce white light. In color displays, the screen is coated with individual phosphor dots that glow in red, blue, and green; three separate electron guns target these specific dots to render a full-color image.2134

This effect is coupled with the controlled deflection of the electron beam using electric or magnetic fields, which allows the beam to scan the screen and create precise images or monitor electrical signals in real time. This technology was first applied to the oscilloscope in 1897 and subsequently became the foundation for television and radar displays.152