# LED seen through metal (MacBook sleep LED light)



## tino_ale (Nov 5, 2008)

Hi all,

Maybe some of you have noticed this specific feature of the new macbook : an LED is hiden behind aluminium, when it's off you don't know it's there. Only when it's on you discover there was actually something, it's amazing how you see the metal turning into light! :thumbsup:

Here the explanation from Apple :


> Then there’s the sleep indicator light. An indicator is functional only when it’s indicating something. Look to the right of the thumbscoop. You see nothing. Until you close the display and your MacBook Pro goes to sleep. Then an LED glow appears from inside the enclosure. How? *During the CNC process, a machine first thins out the aluminum. Then a laser drill creates small perforations for the LED light to shine through. These holes are so tiny that the aluminum appears seamless when the light is off.*



I was wondering how/if this could be implemented into flashlights.

I can imagine 2 ways of using it :
1/ As a battery indicator, or a status light, something like that.
2/ Even cooler, for small AAA keychain lights. The front end of the flashlight would look "closed", yet you could turn it on.

Does anyone know more about this manufacturing process?
Is it patented?
Does it have a name?
Is the metal still waterproof at this location?
Can the micro holes get filled up by dirt?
Anyone knows how much light is lost through the metal?
How thick is the metal at this location?
...

Anyway, I find it very cool.

Any info, please share :thumbsup:


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## Sabrewolf (Nov 5, 2008)

The metal is about 0.1mm thick, before the "Holes"
are laser bored into them. But they may have also
filled in the holes with a plastic injection process
to close them up from dirt intrusion. That "Could"
be done on a flashlight, and still be strong enought
to Edc without punching through over time.
It shouldn't be patented as far as i know... Anything
is possible with apple :green:. Pretty soon, they will have
patented the Laptop itself, and will start to sue the
whole manufacturer list of laptops! I would have to 
say that you would lose about 50% of the light from 
the led when it is sitting behind this setup :thinking:
As far as complexity? Any good laser engraving shop
can do this for you if the metal is thin enough.
As far as sealing up the holes, just use Norland
optical adhesive. It will seep into the holes nicely, and
give you a watertight light! Great, Now i have to go try 
try this out ..


Robert M.


tino_ale said:


> Hi all,
> 
> Maybe some of you have noticed this specific feature of the new macbook : an LED is hiden behind aluminium, when it's off you don't know it's there. Only when it's on you discover there was actually something, it's amazing how you see the metal turning into light! :thumbsup:
> 
> ...


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## tino_ale (Nov 5, 2008)

If you try anything please keep us posted on your efforts!

0.1mm is quite thin, I suppose one should keep the thin area as small as possible otherwise any contact with a hard edge could punch the surface

Norland sounds good but I don't know you could fill the holes


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## gnarf! (Nov 5, 2008)

Fun Fact: The green power indicator LED for the MacBook Pro's webcam has been hidden like this since early 2006. :naughty:


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## IMSabbel (Nov 5, 2008)

Well, for flashlights that would just be form before function: Most of the light doesnt make it through.


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## 2xTrinity (Nov 5, 2008)

IMSabbel said:


> Well, for flashlights that would just be form before function: Most of the light doesnt make it through.


An exception might be if you wanted to make something to act as an indicator, or a locater light. For example, sometimes In my maglites lights I have used constant-driven 3mm UV LEDs backlight a green GID switch cover, so that the light is visible in the dark.

In this case, efficiency doesn't really matter, as battery drain is negligible, and the application is mostly cosmetic, anyway.

A cool feature on a somewhat larger light (with room to spare, such as a mag) would be a red/green LED hidden behind the surface of the metal in this fashion, which would vary is color from green, to yellow, to red as the battery voltage drops.


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## csshih (Nov 5, 2008)

maybe an infrared light would work well with this.


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## tino_ale (Nov 7, 2008)

Sounds like this woud be more suited for an indicator light. But heck, what a cool status LED!


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## LEDobsession (Nov 25, 2008)

I want to try this now. My friend had a commercial laser engraver and I could easily make something .0039"/.1mm to try it on. Anyone know what kind of heat percentage on the laser it would need?

Trevor.


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