# For all the Projection Geeks Out There...



## LavaASU (Apr 16, 2014)

I got to do a little deeper playing with a Barco FLM than I normally do, so figured I'd post some pictures.




And this is what the optics on an FLM look like. I think I've posted some other pictures of them before, but I like this one because it shows the top of the light engine (side cover is a couple of quarter turn fasteners, it takes a bit more disassembly to get the top off). Short version of how this thing makes an image is a xenon lamp makes a whole lot of light which gets turned by a cold mirror (like many moving light reflectors are made out of). It then goes into the black tube called the light pipe where it becomes a even rectangular beam of light matching the DMD chips. It gets reflected by another mirror called the fold mirror (above and beteen the two yellow stickers, it's in a housing you can't see it) into the prism which is made up of 5 pieces. It is split into red, blue, and green, is sent to the correct DMD where it is either reflected to the lens or to the light trap on the top f the light engine. The light reflected to the lens is combined and makes the image. Yeah, it's a bit more complicated that that, but thats the short version. Feel free to ask if ou want more detailed explainations.



Yeah, it gets hot. Whats neat about this is you can see how the UV and IR light gets filtered out as it moves through the optic train. The bright red/white area is the light pipe which is the start of the light engine. The light blue is the fold mirror area. The blue lines are coolant hoses for the DMDs, light trap, and light pipe entrance. 




And this is what the top of the light engine looks like on thermal. The hot spot is the light trap where everything that doesn't go out the lens goes. It would be hottest if projecting black and the coolest if projecting white (I think we had up a grey test pattern, so this is sort of medium). The light trap is also liquid cooled. 



And thats what the light engine looks like (this is the back side). The multipin connectors go to the formatter interface board which controls the formatter boards the DMD chips are mounted on which actually control the DMD chip. Silver piece on top is the light trap. Thats the blue DMD in the center of the image.




And from another view. Silver piece on the bottom left is the cooling block for the light pipe. The actual light pipe/integration rod is a roughly 11cm long piece of glass behind the opening in the black piece in the center of that cooling block. There would usually be a silver mask over the black mask but we'd already partially disassembled this before I thought about pictures. The light pipe is also way out of alignment in the picture. When properly aligned it's actually at an angle to the image that comes out the lens. That something I still struggle with when I'm working on one of these-- the image is not at all at the angles or direction it is when it comes out of the projector while it's traveling though the optics. 



Hey, look what I found! Wonder what that is? Just kidding-- we knew it was there and that was one of the parts we were inspecting (you can't really see in the photo, but it was slightly hazy which means its bad). But the service documentation does not mention this set of relay lenses that sit between the light pipe and the fold mirror. 



And heres a DMD chip. This one's actually from a different projector. You can see where the intense light burned the paint off surrounding the chip (there might have also been some misaligned optics contributing since it's mainly one side burned) which resulted in burned paint dust getting on the chip surface which shows up in the image. The FLM has sealed optics and the DMDs were fine, so didn't take that apart.


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## kevlar557 (Apr 16, 2014)

Wowza! I hope I never have to get that deep into our Christie Roadster 18ks any time soon. I've had to replace a few boards in some Digital Projection Titans before, and I was nervous the entire time haha. Very cool pictures though, especially the FLIR ones.


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## LavaASU (Apr 16, 2014)

kevlar557 said:


> Wowza! I hope I never have to get that deep into our Christie Roadster 18ks any time soon. I've had to replace a few boards in some Digital Projection Titans before, and I was nervous the entire time haha. Very cool pictures though, especially the FLIR ones.



Haha, you probably won't have to. Many shops send stuff like this (light pipe and relay lens replacement) out to the manufacturer or a service partner. The nice thing about most of the modern large frame projectors is they are made to be field serviceable (modular, most parts accessible with covers off). Are your Roadsters the J (liquid cooled) series or the original non-liquid cooled?

It's a Fluke Ti25 by the way. Very nice imager.


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## gafftapegreenia (Apr 16, 2014)

You just like to show off, but if I worked on gear like that, I would too.


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## LavaASU (Apr 16, 2014)

gafftapegreenia said:


> You just like to show off, but if I worked on gear like that, I would too.



Yeah, I wish I normally got to do this level work. I've done a descent amount of field service on these, but this was my first time doing bench repairs on one. A friend who is an extremely amazing projection engineer let me join him on this project.


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## LavaASU (Mar 27, 2015)

Here's the entire liquid cooling system from a Panasonic projector. unlike the barcos the whole system can be removed in a block which shows the layout. I've gotten lots of questions about how projector liquid cooling works lately so thought this might be interesting to others. I'll eventually post some more pics showing the inside of the pumps... This picture is right when I pulled it out of the projector before we drained the system.


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## ruinexplorer (Mar 28, 2015)

From a Christie J series projector. The liquid cooling hoses are actually pressurized. They cool the DMDs only on these projectors. Any leak requires factory repair due to this. The reservoir, pump, radiator, and flow monitor are separate. Here is the light engine and attached hoses.


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## ruinexplorer (Mar 28, 2015)

Here's another view.


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## LavaASU (Mar 28, 2015)

ruinexplorer said:


> From a Christie J series projector. The liquid cooling hoses are actually pressurized.


 The liquid cooling is pressurized on the Js? How are they doing that without any sort of pressure vessel/bladder?


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## LavaASU (Mar 28, 2015)

LavaASU said:


> View attachment 11767
> Here's the entire liquid cooling system from a Panasonic projector. unlike the barcos the whole system can be removed in a block which shows the layout. I've gotten lots of questions about how projector liquid cooling works lately so thought this might be interesting to others. I'll eventually post some more pics showing the inside of the pumps... This picture is right when I pulled it out of the projector before we drained the system.



I should probably explain... the black thing is the pressure vessel (theres a bladder in it... after the fluid system is sealed air is pumped into the opposite side of the bladder as the fluid putting a slight pressure on it). The 2 metal blocks fit onto the back of the DMDs (only 2 are liquid cooled the 3rd has its on fan) and have a pump in them. The silver thing is the radiator (I've been told its actually a transmission radiator from a car but can't say that with certainty).


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## ruinexplorer (Mar 28, 2015)

The hoses have self sealing connectors. The pressure is created when they fill the hoses at the factory. When the hoses are connected to the reservoir, it maintains an airtight seal. Since it is then a closed system, the pump is able to maintain the pressure. If a leak is developed in the hoses, usually at the 90 degree connector to the pump, the entire light engine needs to be returned to the manufacturer for repair.


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## LavaASU (Mar 28, 2015)

ruinexplorer said:


> The hoses have self sealing connectors. The pressure is created when they fill the hoses at the factory. When the hoses are connected to the reservoir, it maintains an airtight seal. Since it is then a closed system, the pump is able to maintain the pressure. If a leak is developed in the hoses, usually at the 90 degree connector to the pump, the entire light engine needs to be returned to the manufacturer for repair.



That makes sense except that when you open the reservoir to add fluid if needed and/or flush the system you'd have the reservoir open with the light engine hoses connected. so what keeps a pressure into the light engine hoses from escaping?

On the Films if you disconnect the light engine hoses with pressure in the hoses they will hold it but as soon as you connect t light engine to something open (eg the cooling bottle which acts as a reservoir in service) you immediately lose all pressure and have fluid squirt out.


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## ruinexplorer (Mar 28, 2015)

You seem to have a misunderstanding that a pressurized system needs to be high pressure. This is not. However, a certain pressure needs to be maintained for the pump to work. If it is not there, the pump isn't strong enough to repressurize the system. If too much air gets in the lines, you risk a critical shutdown. 

Here's a final view of the light engine out of the projector.


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