Reflect the LEDs!


EvilDragon

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Together with the keymat designer and manufacturer, we worked out a solution to improve the backlit keyboard and make everything evenly illuminated.

If you followed the last newspost about the backlight, you know that the lighting doesn't work yet properly, as not enough light gets from the LED to the top of the key.
Right now, we've got 1 LED for four keys. Their light is mainly being absorbed by the black paint on top of the keymat, so it's not really distributed and therefore doesn't look good.


So, here are the solutions we worked out, that should improve things a lot:

1. There will be a reflective silver layer below the black one. The light is not being absorbed anymore but reflected.
2. The PCB will have a huge white silklayer. Then the light will also be reflected back from the PCB. Thanks to 1. and 2. together, the light will not be absorbed but distributed inside the whole keymat.
3. The amount of LEDs will be increased. Instead of one LED that lights up 4 keys, we now have one LED for 3 keys.
4. The material and printed color on the keymat will be made a bit more transparent.
 

These changes will all be done right away, so that the prototypes will already have them included.
 

My contact in Greece also had a meeting with the mould production company today, so expect some more news from there as well within the next few days.
 
Very nice! Can't wait to see how it looks with those improvements. The render with the lit keys looked so nice...
 
Great news ED, I'm guessing the LEDs will be variable intensity to limit the distraction when watching non interactive content like video or in my case 'tail -f /var/log/debug'
 
^ as far as I understood, none of the changes will involve any additional parts, just extra layers on the pcb and keymat... so assembly and disassembly should be unchanged.
 
Very cool.  Looking forward to this.  At least there isn't a worldwide led shortage.   :)
 
Sound good, if this will solfe the lighning issues..

And if these fixes dosnt delay the prototyphe run, than im glad--

And this last thing whit the Case Faktory Meeting also let looking forward for great news ..
 
Wouldnt it be technically easier to use a white PCB to get the same reflection? Less parts less process. Or is that more expensive?

Or have the whole top layer in polished copper, using the negative space for tracing, and double it as heat-sink for the processor with a bit of graphene tape?

On a serious note, is any light getting out of the edges, not only is there a potential difference in illumination there, but the lightbleed could escape out of the joints of the case, that sounds iffy.
 
^ as far as I understood, none of the changes will involve any additional parts, just extra layers on the pcb and keymat... so assembly and disassembly should be unchanged.
Exactly.

Wouldnt it be technically easier to use a white PCB to get the same reflection? Less parts less process. Or is that more expensive?
Or have the whole top layer in polished copper, using the negative space for tracing, and double it as heat-sink for the processor with a bit of graphene tape?

On a serious note, is any light getting out of the edges, not only is there a potential difference in illumination there, but the lightbleed could escape out of the joints of the case, that sounds iffy.
A white PCB is more expensive. A silk layer is standard, almost every PCB has that on both sides (Pandora ones as well).

Polished copper on the top would easily lead to short circuits (i.e. if the keymat contact pad connects it with something else), is more expensive and wouldn't help with cooling as it is on the other PCB side of the processor (and we already have copper layers inside the PCB for cooling).

And no, no light will leak out on the sides. You might see a small glow inside the SD card slots, but that's it.
 
1. There will be a reflective silver layer below the black one. The light is not being absorbed anymore but reflected.

What's the material for the silver layer? Will it not be an isssue for wifi and 3G/4G?
 
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