Illuminated ring / square - Page 1
Forum section: electronics / projects

author: snx
author_rank: Contributor
timestamp: March 15, 2022, 07:26:39 pm
content: Hi GuysMy goal/idea is to create an illuminated circle around something. Much like those illuminated switches:https://www.sparkfun.com/products/15852I have vials that are 30mm long and 20.5 mm in diameter. These vials should fit into a hole that has an illuminated ring (or square-like box) around them which allows RGB illumination (by ws2812 or similar). I tried to cut a 30mm diameter (25mm inside) acrylic tube and tried to illuminate from under the tube "into" the material. This works not so well, since, at the center of the led, the illumination is bright, but gets very dim after a few mm. At least 4 Led would be needed to illuminate the circle even. The longer the tube, the better it works with one LED, after like 500mm, it looks fine, but my length is restricted to around 30mm.I also thought about EL wire, but there is an issue with the small radius and usually no RGB option.Does anyone has an idea here to create something like this in a rather large quantity (120pcs)?How are these switches made? They have very even light distribution in the circle, you usually don't see where the led is.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 15, 2022, 08:29:30 pm
content: Light pipes are the commercial solution, but I don't know that you'll want to swing that for a fairly low quantity run. It's funny I guess, in that 120 is more than you'd want to whip up by hand, and might want to farm out rather than 3D print for example; but it's far short of the thousands+ you'd get a real metal die and injection molded run for. The rub is, light pipes preferably have smooth shiny (polished) sides, so they aren't leaking light everywhere (total internal reflection, TIR).There's also translucent filler stuff, which you see in e.g. rubber button pads. Everything's plastic molded together, so there's no TIR at work, it's just translucent material, clear with just a tinge of filler so it scatters light. Lots of loss, only good for indication, and even then maybe not very legible say in broad daylight.Anyway, the buttons hide the LED in the center, so along with a custom shaped lens / light pipe, they can get even illumination of the ring in not much height, and without compromising the mechanism (because everything's shaped around everything else). Unfortunately, not much usable info there.Could you do something like a light box, where LEDs are shining generally at a white or translucent diffuser, some of which shines through the ring space? Your vials would sit in some opaque cup, bathed with light from behind, but only the annulus around it shines through (which would have to be something like, acrylic tube fitted snugly inside and out, and glued in place; or molded-in-place resin, or everything gets stuck to a clear sheet / front bezel sort of thing, or..). If you need per-vial illumination, not just a general blobby glow across many, it might be okay to put opaque dividers between them, so each vial has a lightbox behind it, doing all this. The lightbox volume doesn't need to be big at all (imagine filling the airspace with resin, the sides of which are therefore painted opaque white, so light ricochets around internally by scattering rather than TIR, then still using enough LEDs at the base to maintain even illumination).Speaking of unevenness; if you do have to use multiple around the circle, would there be any value in sequencing them to make a subtle, vaguely hypnotic swirling motion?What kind of an application is this, some kind of prop or decoration? Or, with vials I suppose it could even be chemical, but most anything that needs that kind of indication (i.e. illuminate the next reagent needed, etc.) would probably be done robotically (e.g. DNA sequencing arrays)? Shrug, seems neat in any case.Tim

author: jpanhalt
author_rank: Super Contributor
timestamp: March 15, 2022, 08:35:29 pm
content: 1) Why do you want to illuminate the vials? What are you trying to show or demonstrate?2) Maybe direct illumination is not the answer.3) If it is, why not just one LED per vial? Light pipes are another solution, but same effect.4) Have you considered pure reflected light, i.e., darkfield? (I am not sure that is the correct term today.)

author: snx
author_rank: Contributor
timestamp: March 15, 2022, 09:02:21 pm
content: To clarify, i do not want to illuminate the vials themselves, I want an illuminated ring around themI've attached a quick drawing. The grey block is the "case", the blue ring should be the illumination, the teal part is the vial glass body, and the black part is the vial cap.The illumination ring should be even lighted and should be full RGB. My application case is pure "decoration", it does not serve a technical purpose. The idea is to place multiple vials in the construction, and then illuminate the rings depending on a selection or display its state.Most of you know the Periodic Table, my idea is to replicate it with the vials (each one contains an element sample and has labeled cap). The led ring will either display the groups (metals etc), display a specific vial (selection), or will display the elements state depending on temperature (liquid, solid, gas).

author: jpanhalt
author_rank: Super Contributor
timestamp: March 15, 2022, 09:10:02 pm
content: I am not an artist, unfortunately. I spent my professional life focused on doing thing with a purpose. Sorry, I couldn't help.

author: mc172
author_rank: Frequent Contributor
timestamp: March 15, 2022, 09:23:22 pm
content: Is it acceptable to require an opaque liner between the acrylic tube and the vial?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 15, 2022, 09:27:16 pm
content: Periodic Table? Sick.Ooh, could also have intensity or rainbow palette or whatever to indicate relative properties (AW, MP, BP, etc.), colors for oxidation states (animating between sequences when applicable?), etc.Does it matter whether the vial itself is lit? (Might want to avoid for certain photosensitive samples or something?..)Tim

author: Someone
author_rank: Super Contributor
timestamp: March 15, 2022, 09:35:53 pm
content: Quote from: snx on March 15, 2022, 07:26:39 pmGreat, LEDs and PCB assembly are cheap. Why go into custom made parts when something off the shelf will do?

author: snx
author_rank: Contributor
timestamp: March 15, 2022, 09:38:20 pm
content: An opaque liner would not be a problem at all. The illustration was just a general idea.It does not matter if the vial is lit. Most samples can be stored in daylight, so no problem at all.Yes, the idea is to provide some features, for example, you can adjust a temperature slider and elements will change color depending on their state,. Also for example, if you select metals, all metals will light up.There is an online version of this, that's where i got the idea to make this "hardware":https://ptable.com/#Properties

author: thm_w
author_rank: Super Contributor
timestamp: March 16, 2022, 12:04:36 am
content: Either get something like this:https://www.aliexpress.com/item/32963152993.htmlAnd use a frosted plastic ring, or other diffusing methods above it.Or as mentioned above, make a custom PCB with a few RGB LEDs on it.I'm thinking if WS2812 or discrete LED would be easier. You don't need the wank factor of individually controlled LEDs, but, that is how those alix rings are setup.8 LEDs per board, so 960 LEDs total. I don't think you'd want those all in series, so maybe mux a few channels out.

author: mc172
author_rank: Frequent Contributor
timestamp: March 16, 2022, 01:49:17 pm
content: Quote from: snx on March 15, 2022, 09:38:20 pmWell, I wrote a long post with diagrams and all sorts pertaining to what I had in mind but nearing the end realised that I'm massively over-complicating the problem. If you just lightly sandblast or somehow rough up the top surface of the acrylic tube a bit then your four LEDs in a circle would probably look quite nice, especially if you don't run them at full brightness. The more LEDs you can get in the circle the better really.

author: snx
author_rank: Contributor
timestamp: March 16, 2022, 09:04:14 pm
content: Today i disassembled a small old lcd display, it looks like the background of the 20x60mm display is illuminated by a single piece of plastic material with a white background and two small SMD LEDs.The plastic material looks like acrylic but has a special pattern in there. Maybe I can source this material in a square form and then water cut a circle in the middle and put a frosted normal acrylic over it.Also spotted these:https://multitron.co.uk/light-guides-light-pipes/corona-circular/Exactly what I would need, but sadly the diameter in the middle is too small....and the oblong shape is an installation problem. I will try to replicate it

author: Buriedcode
author_rank: Super Contributor
timestamp: March 18, 2022, 09:10:08 pm
content: I've had limited success with DIY light guides/pipes. The problem is the effort to get specific shapes and/or textured surfaces to bleed the light out the light guide. Brightness is rarely a problem since LED's are so bright these days, but uniformity is. Even with a heavily sanded/sandblasted surface, if a lightguide is lit from below (light pointing towards the face/user) then hot spots will still be visible. The only way around that is making the light guide out of a diffuse acrylic, or a milky acrylic - that can quicky attenuate the light which limits depth. Either that or angle the LEDs so they don't light the lightguide directly.The lightguides in modern LCDs are really a modern marvel. Originally dimples were molded into the plastic, or white dots were painted on to "extract" the light from the lightguide (that keeps the light inside by total internal reflection). The further away from the lightsource, the more dense these dots/dimples were because the less light was available - that way it provides an even "glow". These days they are designed and micro etched so they can be stupidly thin, and direct the light exactly where needed, reducing the amount of diffusion sheets required. But as you found out - its all for linear/flat illumination. THe principles are still the same though - shine light into a clear plastic so it bounces around there with total internal reflection, and etc/sandblast areas you want the light to escape from.This all depends on how cheap or DIY you want to go. I've wasted a lot of time cutting, sanding, and molding parts with some success. If you're into experiments, buy some acrylic tubbing and some sandpaper, and a few LEDs - maybe some hotmelt glue which makes an excellent diffuser, and go to town. But if this is for work/contract, I'm afraid I'm un aware of any manufacturer that can mold plastics in any low quantity.