Using a LCD panel as eye shielding for a lasercutter/engraver
I'm not entirely sure whether this post should be here or in the CNC section.
Since I can't find any information online and I know the owner of DIY Perks has some pretty unique ideas I thought this is the place to go for like-minded people.
I just disassemblied a LED TV for salvaging some parts for a ceiling panel lamp (thanks DIY Perks for the idea) and when I was about to get the LCD panel to recycling the idea hit me: What if I were to use the panel for my diode laser cutter/engraver enclosure? I'm about to buy this machine and I will need an enclosure but I want to customize it. Plus, the costs for such an enclosure are prohibitive if you go for extra safety and quality.
I only have basic electronics knowledge and I'm definitely not knowleadgeable enough to decide this without a bit of specialized assistance. What I know is that the double polarization inside the panel absorbs as much light as possible so in theory this LCD panel would be more effective than the orange acrylics out there.
How about the safety of using it? It's unlikely the insides of the enclosure will be exposed to much heat due to exhaust and safety automation to be included. But still, ther emight be other factors I don't grasp.
What do you think?
This is an area (although I can't speak for Matt) that I would leave to experts and commercial manufacturers.
In operation, laser diodes are extremely dangerous for our eyesight and it's not something really suited to a DIY job because even IF I detailed how to do it here, a simple error could end up with someone losing their sight.
I expect you're thinking of something like the LCD shutters used in automatic welding helmets which are (broadly) transparent until the arc strikes and then go "totally" black. (These helmets are also intended to block both visible light and invisible, high energy UV radiation more than the bright arc. The arc is intense but the UV can cause sunburn and it's that that damages the retina.)
Only they don't, there's always a certain amount of light leak due to manufacturing tolerances and so on. You can see this in the way that LED-LCD displays (not OLED) don't display blacks too well and often need some level of software support to achieve their X:1 contrast by selectively dimming some of the backlight LEDs. (Older displays driven with fluorescent backlights can't do this at all.)
Your laser will be operating at the other end of the spectrum (at least when we consider the "just outside of visible" bits) generating a huge amount of heat in a localised area. They are safe(ER) than UV but still aren't something to fool with as the beam can reflect and hit you right in the eye resulting heat damage to the retina potentially resulting in blindness.
Safety optics isn't really in my wheelhouse but I expect those yellow filters are actually very dark or even largely "black" to infra-red so it's possible to keep any eye on what's going on without risking your sight from an inadvertent bounce.
I think Matt did do a video separating the various parts from the glass and he's even done a double-layered LCD gaming monitor.
Take everything I say with a pinch of salt, I might be wrong!