A luminous watch is a type of watch that can emit light in the dark. Its principle is to utilize the luminous effect of phosphor.
The dial and hands of luminous watches are usually coated with a layer of phosphor, which is a substance with fluorescent properties. Under normal light, the phosphor will absorb light energy and store it. When there is sufficient light, the phosphor absorbs light energy and is in an excited state, thus being able to emit light in the dark.
When the ambient light dims, the phosphor gradually releases the previously stored energy and emits green or blue fluorescence. This kind of fluorescent light can be perceived by the human eye and can make the entire dial and hands present a luminous effect.
The duration of the luminous effect of the phosphor in luminous watches depends on the amount of light energy absorbed by the phosphor and the rate at which it releases energy. Some luminous watches are also equipped with light source sensors. When they detect dimming of light, they automatically activate the phosphor, thus keeping the watch glowing all the time.
Overall, the principle of luminous watches is to utilize the light absorption and luminescence properties of phosphors, enabling the watch to emit light in the dark, making it convenient for people to read the time at night or in low-light environments.
