Matching LCD enclosure to alphanumeric display

[ricko_uk]

Hi,
this might be a stupid question, but in the past I always 3d printed the enclosures for hand-held applications with a display, so first time I came across this issue...

This time I need a hand-held enclosure that is very robust and professional looking. And I need to use it to enclose a 6 button (up, down, left, right, ok and cancel) as well a 4x20 or 4x16 character display (or less preferred 2x20 or 2x16).

The display I'm considering at the moment is this one but can be flexible if needed: https://www.digikey.co.uk/en/products/detail/orient-display/AMC2004AR-B-Y6WFDY-I2C/22531846
(or alternatively a 4x16)

But all the enclosures that I came across like this one: https://www.rose-systemtechnik.com/en/rose-products/27020200/ seem to have mounting points for a display but not corresponding to the actual display's holes position...

Am I missing something perhaps in the way the (enclosure manufacturers assume) the displays are going to be mounted into the enclosure?

Can anybody either share some pointers/suggestions or perhaps some enclosure with mechanically-matching character display?

Thank you

[shabaz]

I don't know if it's very orthodox but if it were me, I'd glue a neutral density filter to the inside of the enclosure cutout, and then create a smaller frame using black card or matt plastic, and place that over the LCD screen (could use double-sided tape on the edges). Then the LCD screen could simply be placed at any reasonable distance away from the cutout+filter, perhaps on a PCB with mounting holes in the appropriate places to match the enclosure PCB mounting points. The frame prevents the circuit board components from being seen.

[ricko_uk]

Thank you Shabaz,

what do you mean by neutral density filter? I only know them in the context of photography and when I just googled it nothing came up that makes me think they could be used in this application. Could you please explain what you are referring to exactly and the reason for using it?

Thank you

[shabaz]

Photography type material could be used, it may be cheaper (since it's more popular). Something like the attached item, it is just a sheet of plastic about 1 or 1.5 mm thick (i.e. it is solid, not the filter gels, and can be cut just like sheet plastic), and is low-cost. It comes in different densities, maybe try ND4 or try a couple of different values to see what suits your needs.

It improves the contrast a bit (since the outside light coming into the enclosure from outside is filtered coming and going out), and just looks neat because it is usually unscratched, so it looks like a high-quality window into your product!

Similarly, for the card frame inside, there's probably photography related card which is deeply black and matt (I don't know that it needs to be; I simply used any black card I had, and cut the hole just slightly larger than the LCD display area, and stuck it to the metal frame of the LCD. Result looked neat (at least to me).

[ricko_uk]

Thank you Shabaz.

[shabaz]

Incidentally, I randomly came across a low-cost method to make a repeatable cut-out.
I was looking for a way to store small parts and found that AliExpress has steel cutters that are usable with foam sheets.

The photo shows a quick attempt with 2 mm neoprene foam (aka craft foam) on a little LCD screen.

Custom shapes cost just $20 or so from AliExpress. The custom ones come pre-fitted in a wood holder.
Ideally, a press of some sort would be used, but for a one-off, with the smaller shapes, it's possible to use scrap wood as shown in the photo and use hand force (a lot of it!).

It's a bit of a niche method to make an LCD surround since, for a one-off, any material could just be cut with scissors/craft knife, and for production, there will be plenty of firms that could make a cut-out on matt material cheaply. But maybe there's a use for it occasionally.

[jwet]

Rose, Bopla and Pac-Tec etc routinely do customization to cases if your volumes approach a few thousand.  If you get up to 5k, they can even put inserts in the mold inserts into the mold.  Full custom injection molding (with Alum tooling) from China has gotten reasonable for 10K like quantities- the average tool life.  At low volumes, you're stuck a bit- there is no run to amortize the cost over.  Industrial Design firms use modelling companies that can make short runs of nice looking enclosures for trade shows, etc.  College ID students often even pay to have models made like this for their capstone senior project- a few thousand but highly negotiable.

Rose probably had a requirement from someone for that config and sell it as a standard product.  Call them and talk to their apps guys.

[ricko_uk]

Thank you shabaz and jwet.