Some kind of plastic needed

Title is a bit vague for a reason, as I'm hoping somebody here can point me in the right direction.


I've got some LED matrix displays that I need to use outside, however in bright light they're not visible. After some experimenting last year, we found placing a piece of cloth in front of them makes them visible, however that's not exactly an ideal solution for something that's getting used outside. So I'm looking for some kind of tinted (or possibly thin fully coloured might work) plastic to place in front of the matrix's, with ideally some kind of matt finish to minimise glare.

I've never had much dealing in sheet plastic, so has anybody got any idea for what I'm looking for, and where I might get some small offcuts to try before commiting to the full size needed?

A little trick you can use is to use the spray paint for glass that creates the obscured effect like for bathroom windows. just use a light coat.

Must be an old age thing as I'm having problems visualising what you want to do lol, what sort of thickness plastic are we talking about & what's it to be fitted to? First thought would be self adhesive vinyl but I might be missing something.

frosted acrylic might do the trick
opaque acrylic might be a bit too restrictive unless its really thin
it shouldn't cost to much to buy a slack hand full of various bits and bobs to try

if you have access to a sand/shot blaster you could do both sides of a clear acrylic sheet to stop the glare on the outer face?

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Originally Posted by blackburn mark

if you have access to a sand/shot blaster you could do both sides of a clear acrylic sheet to stop the glare on the outer face?

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You only need to do the outside surface, not the internal one that the leds are on or you are just reflecting light back towards the led instead of into the acrylic and out the other side, using a fine grade paper on an orbital sander works a treat.

This is the smaller display I've been using for testing -
http://farm8.staticflickr.com/7130/7...9dd7f99a96.jpg
110_MatrixDisplay by mc_mtb, on Flickr

As you can see, when it's dark it's nice and clear, however during daylight you can't really see the lit LEDs.
Here's the display in daylight, with what we bodged over it to make it visible (it's not powered up, as I'm not sure where I've put the controller for it at this present moment - I tidied up last week!)
http://farm9.staticflickr.com/8100/8...eebdbae651.jpg
LED Matrix by mc_mtb, on Flickr

Vinyl may work, and I know where I can get plenty offcuts. Not sure why I never thought of that.

However I've discovered the plasticshop do samples, so I've ordered some of their frosted samples in dark shades (midnight black, slate and stone grey), as it should give me the finish I'd ultimately like to acheive.

If you know where you can get lots of vinyl off cuts then ask them if they have any translucent off cuts or even frosted you can try. Translucent is what is used for lightboxes so allows more light through & frosted is available in different colours & will also allow more light through. Both have a matt finish which will help with the glare.
Don't know if these get moved about a lot but if you go down the sheet material route then polycarbonate might be a better option than acrylic, acrylic tends to be a bit brittle but make sure it is an exterior grade. Exterior grade is UV stabalised which stops it yellowing over time.

Another option if you are still experimenting & still have units to manufacture is to change the colour of the LEDs so they show up better during daylight hours.

This will only be getting used a few times a year, and will spend most of it's life wrapped up in a shed, so I'm not too bothered about UV stability. The ability to not fail in rain is far higher on the priority list!
It's going to be built into a box, so I'll make a cover to protect the front during transportation.

What are you going to use for manufacturing the box? Something like aluminium composite would probably work quite well, it's light & pretty hard wearing & you can fold it into a box shape fairly easily by routing a "V" grove to fold along. would reduce the number of joins you would have to worry about sealing.

Not got that far yet!

Main panel that holds everything will most likely be aluminium, which will then have the perspex mounted closely in front of it. Then all that needs a box around it. I might just go for something like ply for simplicity, then give it a good prime, and paint.
I've got somebody who could do the woodwork for me, which saves me time. If I go metal I'd have to do it myself.

Maybe the acrylic diffuser panels they use for the light units in paneled ceilings maybe a better bet?

Composite board has a thin aluminium skin with a plastic centre. OK it's a lot more expensive than say far eastern ply but the whole thing would be lighter & easier to move about, it's already powder coated so no need to paint & comes in about 6 different colours plus it's pretty easy to cut so your woodworking guy could still manufacture it for you. Normal woodworking tools will be ok as long as any saws are fine toothed, for small jobs I use one of those throw away laminate saws that joiners use & the V groove I do with a normal hand help router.
Not the cheapest way to do it but would look good & last for years.

Most of the old clock radios and such like used (brown/green) tinted acrylic to reduce the glare.

May if missed the point here but you can buy frosted vinyl no problem. If it needs cutting to a certain shape let me know and I will run it through my vinyl cutter

With Birchy, it`s a contrast rather than diffusion problem, dark tint will work better than a frost.

Amber LED might work better as well, high brightness, `sunlight visible ` are reliable and relatively cheap.

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Originally Posted by Musht

With Birchy, it`s a contrast rather than diffusion problem, dark tint will work better than a frost.

Amber LED might work better as well, high brightness, `sunlight visible ` are reliable and relatively cheap.

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I think your right about changing the LEDs for a different colour Bruce but not sure if that is still an option.

Changing the colour of the LEDs at this point isn't going to happen, as the only commonly available matrices use Red and Green.

I'll see how the tinted perspex samples work out first.

Green will appear brightest, but it`s the least reliable colour and is very sensitive to ESD.

The perspex samples turned up last week, but I've only just got around to setting up a panel to try.

http://farm9.staticflickr.com/8241/8...f9ef72f4d2.jpg
Display Testing by mc_mtb, on Flickr

The Frosted Slate Grey works pretty well, and only becomes illegible when I shine a 670lumen lamp directly at it, so it should be good once positioned suitably out of direct light with a hood.
Only issue with the perspex is you've got to buy it in a complete sheet, which means it works out pretty expensive, especialy since I'll probably only need under quarter of a sheet, so I'm waiting for somebody to drop of some frosted vinyl samples, which I'll try on some clear perspex to see how it compares before making any decisions.

window tint film springs to mind....

MC,

Only just got round to reading this thread and I may be able to help.

A few years ago i built a Shumatech DRO system which uses red LED's but in bright light you see all the variation on the led display so a 6 looks a lot like an 8.

Some one posted a link to some red film that once put over the display made it clearer.

As I couldn't get any of this film, it was US sourced I tried using some clear OHP inkjet projection film printed solid red and it worked.

Perhaps given the price of OHP film being low you could experiment with various colours ??

Could try theatre colour filter, gel, not self adhesive though , sandwiching in between 2 layers of clear acrylic works at a push.

Quote:

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Originally Posted by Musht

Could try theatre colour filter,

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This stuff might work

FILTER GEL SHEET 48 X 21 STAGE LIGHTING VARIOUS COLOURS | eBay

If not you could always try rear projection film, that will definitely work.

I think I may have some OHP sheets around somewhere. I'm currently wondering if a layer of vinyl, then a more opaque frosted perspex would work better, as I've just been doing some searching, and it seems frosted vinyl only comes in light/pale colours.

One goal I want is an anti-glare finish, which is best acheived with a dark satin/matt/frost finish.

Either matt or translucent vinyl would do you, no need for frosted acrylic

Just a thought as I was sitting here this morning. Is it just the glare that is causing problems? If so have you tried a clear matt laminate? Clear laminates are used over digital prints for a number of different reasons, they are basically a clear vinyl but available in gloss, Matt, satin & crystal finishes.

Have you tried sheetplastic.co.uk - they cut to size. You can always phone or email for a price.