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What are all the different types of lenses available for LEDs? I'm looking for a lens that would result in an effect similar to that of a 7-segment where a single LED creates a line segment of light.

Also, to make the question more general, and probably a little more useful to other people, how do you go about finding a lens for any LED application? I assume lenses are different based on size of led, surface mount/through-hole, viewing angle, desired diffusion etc.

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  • \$\begingroup\$ Nothing to do with electronic design. \$\endgroup\$ – Leon Heller Jul 28 '11 at 15:34
  • \$\begingroup\$ @Leon does it have any less to do with electronic design than electronics.stackexchange.com/questions/2089/… ? \$\endgroup\$ – NickHalden Jul 28 '11 at 15:40
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    \$\begingroup\$ But it is relevant to the design of electronics (finished products). I'm sure there's some case questions that have no electrical merit, but they are still useful here. \$\endgroup\$ – W5VO Jul 28 '11 at 16:01
  • \$\begingroup\$ @Jgord, this does fit into our site but be cautious, another unclosed question is never defense for the current question. If something is off-topic and you link me similar to prove your point I will just close both. \$\endgroup\$ – Kortuk Jul 28 '11 at 19:35
  • \$\begingroup\$ @Kortuk haha, fair enough. \$\endgroup\$ – NickHalden Jul 28 '11 at 20:31
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What you're looking for is also called a "light pipe" or "light guide." If you're designing a product for high volume production, the mechanical design team can create custom ones. They're just little pieces of clear plastic that go between an LED on the main circuit board and the edge of the product case. Most off-the-shelf ones are designed for generic high-volume uses where custom mechanical design doesn't add much to the product value, like an array of lights on the front of rackmount equipment. It seems unlikely you'd find exactly what you're looking for since it sounds like an unusual scheme. If you're a hobbyist you might be able to cut a piece of Plexiglas, or custom mold something that works reasonably well out of epoxy. The optical properties of the material won't be the same but it might work well enough.

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  • \$\begingroup\$ Hm, I did a quick google image search for that and didn't really see anything like what I'm looking for. They all seemed to be tubes that simply redirected the direction of the LED. I'm looking for one that would take a small SMD led and disperse the light to light up an entire segment of a 7 seg LED basically. Perhaps it is called a reflection chamber? \$\endgroup\$ – NickHalden Jul 28 '11 at 20:37
  • \$\begingroup\$ I would think most people buy a 7 segment LED as a component rather than try to build it one line at a time. How big are you trying to make it? Might be easier to take apart a jumbo alarm clock or some such than build it from scratch yourself. \$\endgroup\$ – Matt B. Jul 28 '11 at 20:55
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    \$\begingroup\$ Ok I lied, I'm not building a 7 segment LED. I'm building a watch but I want the digits to be similar to 7 segments. So I want really small LEDs to be able to light up a small line segment (0.25" x 0.04" or thereabouts) evenly. I do not want them to appears as points of light. \$\endgroup\$ – NickHalden Jul 28 '11 at 22:59
  • \$\begingroup\$ You want a diffuser: rpcphotonics.com/engineered.asp \$\endgroup\$ – pjc50 Oct 29 '13 at 16:41

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