Why most, if not all barcode sensors, optical mouse use red lights, and not blue or green or other lights?

Answer 1

Red light's frequency length is such that it cannot be easily disrupted by ambient light. It allows the sensors to work in daylight, an essential function.

Answer 2

well I suppose they could have been those colors... I think the main point of the coloring system was to differenciate. Bright color, like red captures the attention and tells us to stop- yellow is not quite the same, but still attention grabbing. Green is mellow, so we're allowed to cruze on through. Yet green is totally a different color scheme so it's easy to tell the difference from a distance. Personly, I think orange would be awesome in place of yellow... but then it'd be a litttttle too close to red... I think I'd stop when I wasn't supposed to... (and probably get honked at~! lol)

Answer 3

There are a number of reasons to use red. The wavelength of red light is longer meaning it is less likely to be scattered by small particles. Since the wavelength is longer, the frequency is smaller and the energy per photon is less. This means that red laser light is easier to produce and requires less energy. Red lasers are quite common and cheap where other lasers are much less common.

Answer 4

They could just as well use green or blue lights, but red or near infrared semiconductor emitters and receivers are far easier and cheaper to produce, especially if the light source has to be a laser.

Answer 5

red light has longer wavelength.. hence it does not easily get scattered by particles in air... barcode reader recieves the reflected light from the white part on the barcoded area.. the recieved light is analyzed to identify the code .. if any other colored lights are used the reflected light may b the light reflected in air hence it will not b accurate enough.

Answer 6

I do not think wave length or scattering etc are reasons for such a short distance.
It is simply because red is easy and cheap to produce.