Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Why do most optical mice use red LEDs?

  • Is it necessary that a mouse's LED is red?
  • What other colors can/can't be used?
  • Does using another color changes the main design of the mouse?
  • Does it makes manufacturing mouses harder or more expensive?
share|improve this question

closed as not constructive by Ƭᴇcʜιᴇ007, Breakthrough, Karan, Scott, BloodPhilia Jun 6 '13 at 12:21

As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance.If this question can be reworded to fit the rules in the help center, please edit the question.

12  
en.wikipedia.org/wiki/Optical_mouse#LED_mice: "The color of the optical mouse's light-emitting diodes can vary, but red is most common, as red diodes are inexpensive and silicon photodetectors are very sensitive to red light." –  Ƭᴇcʜιᴇ007 Jun 3 '13 at 3:57
1  
I'm not sure why this is getting downvoted... it's actually a pretty interesting question. The question could use a little editing, but there's nothing fundamentally wrong with it. I'd be interested in seeing an answer that actually explains how an optical mouse works and why red might be preferable. –  nhinkle Jun 3 '13 at 4:21
2  
There's a lot of blue (like bluetrack mice) and IR led mice too. Red LEDs are cheap tho, and have been around the longest –  Journeyman Geek Jun 3 '13 at 4:24
4  
@nhinkle Maybe because "this question does not show any research effort"? People are linking to Wikipedia articles… –  Daniel Beck Jun 3 '13 at 7:09
    
@techie007 I saw the Wikipedia article, but those 2 lines didn't satisfied my knowledge hunger. I tried to search for it, but I didn't find a good detailed explanation. Also never asked in any SE sites, so this could be a potential Google search landing page. I also agree with nhinkle. –  totymedli Jun 3 '13 at 11:39

3 Answers 3

up vote 8 down vote accepted

It is not necessary that it be red. Any color can be used, even invisible (infared). The asthetical design usually does not have to change, but internally it may due to the different type of laser diode. Red lasers are cheaper and readily available. Other colors do exist in consumer products currently, the most popular alternative is green.

share|improve this answer
  • No.
  • Any colour can be used.
  • No.
  • Both.

Refer this Wikipedia article.

share|improve this answer
10  
It'd be nice if you could expand your answer to more than just a few words, but add a little context and explanation. –  slhck Jun 3 '13 at 5:58

Red colour has the most dispersion compared to other colours in the visible spectrum, violet having the lowest.

Dispersion means how much light can 'spread', 'disperse', 'scatter', etc. It is the same reason that traffic lights for stop are red. This is so that the sign is visible even from long distance & with different viewing angles.

For similar reasons the mouse may be using the red colour. Not everybody uses the mouse on perfectly flat surfaces!

share|improve this answer

Not the answer you're looking for? Browse other questions tagged or ask your own question.