PDA

View Full Version : Flat screen TV.



Robert Schmiede
08-18-2014, 5:58 PM
just thought I would share this. My flat screen TV went kafut, needed some small screws so I pulled it apart,inside was a sheet of 1/4 inch thick acrylic with a honeycomb type print over it,cleaned off with acetone.put it in the laser,cut a circle,beautiful.no doubt cast acrylic. A quick run to the local recycler.:rolleyes:

David Somers
08-18-2014, 6:04 PM
Robert,

I may be wrong, but I think that is something called an LGP or Light Guide Plate? It is designed to take side lighting, like you find in an LED/LCD TV, and distribute the light throughout the material.

I found a bunch of reference to this stuff in a Chinese laser manual and it was such nonsense so far as the translation was concerned that I started hunting down the references trying to make sense of them. That was what I came up with. Interesting stuff. Lots of different commercial and industrials uses. And lots of variations on how it is designed and looks.

That is my guess? Anyone else with a good theory? Or an actual clue? <grin>

Dave

Dan Hintz
08-18-2014, 8:43 PM
Robert,

I may be wrong, but I think that is something called an LGP or Light Guide Plate? It is designed to take side lighting, like you find in an LED/LCD TV, and distribute the light throughout the material.

I found a bunch of reference to this stuff in a Chinese laser manual and it was such nonsense so far as the translation was concerned that I started hunting down the references trying to make sense of them. That was what I came up with. Interesting stuff. Lots of different commercial and industrials uses. And lots of variations on how it is designed and looks.

That is my guess? Anyone else with a good theory? Or an actual clue? <grin>

Dave

Light diffusers are typically acrylic with engraved lines and/or dots, side lit with LEDs or CCFLs. These markings will be visible to the naked eye, so if it looks like a regular sheet of acrylic, it's not a light guide.

Dennis Rech
08-18-2014, 11:35 PM
just thought I would share this. My flat screen TV went kafut, needed some small screws so I pulled it apart,inside was a sheet of 1/4 inch thick acrylic with a honeycomb type print over it,cleaned off with acetone.put it in the laser,cut a circle,beautiful.no doubt cast acrylic. A quick run to the local recycler.:rolleyes:

I have friends in the electronics recycling business and they save these panels from LCD monitors for me.
Most is 1/4 to 3/8 inch in thickness.
What i get isn't acrylic, it melts into black goo in the laser.
It isn't polycarb, it sticks to the router bit and it fractures when bent.
It routes with a fair amount of fuzz.
It cuts best in my cnc mill with coolant and slow speeds.
I have found the best use for it is as spoil board material on the milling machine table although I have made a number of tool and collet holders with it.
Dennis

Robert Schmiede
08-19-2014, 12:54 AM
hi Dennis,this is my cuts with a 80 watt Chinese laser.No black goo.Maybe not all tv's are the same. 295126

Dan Hintz
08-19-2014, 5:52 AM
Frosted... looks like a light diffuser.

Robert Schmiede
08-19-2014, 7:42 AM
hi Dan, not frosted, even though looks frosted in the photo. They are being sold on eBay as plexiglass, from TV,s. I agree a light diffuser, cheaper than an optical diffuser.i will post other photo in the morning.

Mike Audleman
08-19-2014, 10:46 AM
Shame you shipped the TV off to the recycler so fast.

Yes, that clear piece you harvested is to distribute the backlight uniformly across the screen area. Also to be liberated had you dug a bit deeper is some polarized plastic, some backing plastic sheet. And depending on model and type, a front frosted or clear plastic sheet (probably flexible). There might have been a small florescent tube or side lighting LEDs that you could have harvested. All useful stuff. There was probably a power supply module that could have been salvaged for use (led rope lights, projects etc) and various connectors on the rear are frequently useful for projects.

David Somers
08-19-2014, 1:53 PM
Mike!

Remember that section of your laser manual you have that sounded like a passage from Jaberwocky, after it had been run through a cell phone spell checker? I think I found that same manual which was where I ran across the term JGP. I got so curious what they were trying to say that I started parsing it out and figured out what the JGP was. I also figured out the rest of that manual section. I can't take time right now, but will send you my "translation" later if you want. I don't think it is anything you need to be concerned with. It all seems to apply specifically to cutting and engraving on that material, which appears to be really common in China.

My great fear in life now is I may become fluent in really bad Chinglesh.

Dave

Mike Audleman
08-19-2014, 2:17 PM
Mike!

Remember that section of your laser manual you have that sounded like a passage from Jaberwocky, after it had been run through a cell phone spell checker? I think I found that same manual which was where I ran across the term JGP. I got so curious what they were trying to say that I started parsing it out and figured out what the JGP was. I also figured out the rest of that manual section. I can't take time right now, but will send you my "translation" later if you want. I don't think it is anything you need to be concerned with. It all seems to apply specifically to cutting and engraving on that material, which appears to be really common in China.

My great fear in life now is I may become fluent in really bad Chinglesh.

Dave

LGP == Light Grid Panel. Yea, this thread was the proverbial lightbulb and I guessed that the tool in RDWorks generates the engraving pattern to produce one from a piece of acrylic. Doubt I would ever use it but, hey, I have extra LED rope lights left from my 5m roll I bought to light up my laser's cutting bay :) Either I put them on my truck or make a cool LGP. Maybe both :)

Robert Schmiede
08-19-2014, 6:40 PM
photo of cut light grid panel.295244