I wasn't sure if I was going to PLOG my design or not, I never keep records of anything I do but I decided I would give it a try.

I'm finally starting construction on my projector tonight (Saturday the 27th). I'm attaching a photo of the workbench I built several weeks ago. I wanted a large table that I can stand at comfortably and work. The table top is 42 1/2" tall by the way. I've got 95% of my materials on the bench in this picture. The boxes contain hardware from McMaster Carr.

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I have finished the mounting fixtures for the pro reflector and the right angle first surface mirror. See photos below.

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Pictures continued.

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Lookin' good so far!

45.0º! Nice!

I predict you are going to make a top knotch build...

Looking good already

Never seen one of those angle things before, might have to go find somewhere that sells them even if i never use it

In my quest to build an HD projector I have accumulated two used Sharp 15.4" WUXGA LCD panels and a third new panel from the last group buy. On one of the two used panels I noticed it had some small "grey" spots here and there on the screen. It didn't seem to be "dirt" on the surface nor dead pixels. I'm thinking about sending the pannels to Screentek to have them re-polarized. I don't want to spend $100 per pannel only to have the spots show up worse with a high gloss coating. Today I took my LCD panels, driver board, and notebook to work with me to have a look at the LCD under a stereo microscope in an attempt to find out where the grey spots are, under the antiglare coating, or within the glass itself.

I also attached a Coolpix 4500 camera to the microscope and took several pictures of the top surface (on the antiglare film), then focused just beneath the surface (still within the thickness of the antiglare film), and then on the pixels. It shows how much the antiglare film can affect the color and sharpness.

This is a picture of the LCD pixels. Aprox. 15X. The blured pixels are from the antiglare film.
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In this picture (Aprox. 125X), in addition to the panel being turned on, it is also lit from the side. The large spots are from dust specks and tiny pits in the antiglare film, the fuzzyness is mostly from the rough surface. The brighter specks in the upper part of the pixels are the transistors, which have been highlighted by the side light.
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I focused the microscope just below the surface of the antiglare film, the magnification is aprox. 250X. You can see how much the film distorts the pixels at this magnification.
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In this final picture I focused directly on the pixels (Aprox. 250X). The image is still a little blurry through the film. The dark band in the upper part of each pixel is where the transistor is located.
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Incase you were wondering, the grey spots became more sharply defined as I focused below the pixels. This leads me to the conclusion that there is dirt between the back light and the LCD causing the grey spots.

Thats interesting...
I know this has been talked about somewhere, and some were not convinced it was the polarizer...
The 15" titanium 1ghz G4 powerbook screens are INFAMOUS for the same problem. So much that apple had to extend the warranty on the LCD.

Mine has this problem, but I missed out on the warranty.
If your dirty backlight theroy is right, then I might have to take my powerbook apart for a cleaning!

Your build looks great so-far by the way
Keep up the good work!

Thanks, I still have a long way to go though. I hope to verify my theory when I take my LCD apart. I may try to remove the antiglare film myself instead of sending it to Screentek.

I doubt that there is any dust specs behind panel,,, built in clean room enviro,, the effect is most likey to be focus diffraction rings caused by lens effect on A/G surface (acting like mini lens)

Could be. I should have taken a picture of it. Under the microscope it looked like a mis-shapen grey oval covering at least a half dozen pixels. It only became more sharply focused when I focused below the pixel layer.

I've received another shipment of parts for my build. When I finish the frame work, I'll need to cover my projector with something that looks decent. I first thought about 1/8" - 1/4" thick plywood, painted black. That may look so-so and would probably add a number of pounds to the projector. I also thought about not painting the plywood and applying a plastic laminate to make it look better than painted plywood. That would still add a number of pounds and be a little more complex to do.

I've decided on using another material, something that sounds cool, looks cool, something that, as far as I know, no one else has used in their build. It will hopfully give my projector a high tech look and keep the weight down.

What is it? I'll give you three guesses....

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Here is a close up of the material, it's slightly fuzzy.

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The answer. Carbon Fiber. Neat.

I just suggested carbon fiber to someone the other day, but I was kidding. Then I looked at prices earlier today. How much did that sheet of carbon fiber cost you? How thick is it?

I bought the piece to make sure it's what I want before I commit to buying a larger quantity. It's 12" X 12" and only 1/32" thick. It was about $33-$34. I may use 1/16" - 1/8" thick material on my projector.

There hasn't been much progress in building my PJ. Last weekend I spent my time soaking my 15.4" WUXGA LCD with towels to strip the AG myself. I ended up ruining the $360 panel. Water got under the polarizer and caused a lot of discoloration as well as damaged ffc connectors along the side, causing white lines across the display. I also put a number of large scratch marks on the screen from the razor blade. :angry2:

I have one panel left, I don't think I want to try to soak it, I may try to polish the AG film. I got some Mothers Mag polish last night. I've been trying to decide if I'm really going to polish it or not. I'm betting it will take a lot of time and elbow grease. There are a lot of long threads regarding this, I 've read as much as I could but not all. I'm not sure of the final out come, is polishing the best alternative?

I have 2 WUXGA panels and was brave enough to only remove the back reflective layer on one. I tried the front AG and it didn't budge. The result? A white horizontal line across the display! :angry: I swear that I was very careful with the connectors.

The way I look at it now is that I have a panel to complete building the sled, etc. Then when it comes for final assembly, I'm not going to touch the new WUXGA. I'm going to hire a friggin' surgeon to do the transplant and be done with it.

Although I haven't removed the AG from my WUXGA yet, I did try on a 17" test panel I had. I tried the water stripping method first thinking "hey it's water, it's safer." 20 hours later I was not able to get the AG off, and had only pretty much ruined the panel (which was technically salvagable).

I then tried some paint stipper on the test panel. ~25 MINUTES later I had a nice, shiny, AG free area. Sure, it's a little scarry putting such a harsh chemical on a sensitive piece of electronics, but the paint stipper is so much easier to control. Scraping on the panel is also scarry, it's my biggest consern, but the stipper pretty much turns the AG into goo. The scraper isn't so much for scraping as it is for seperating the goo from the panel. As a test I used my fingernail, which worked just fine (until the stipper melted the glove I was wearing). I'm presonally going to use the rubber from a squeegee when I do my WUXGA. I figure it'll disolve, but what do I care? As long as it lasts long enough to get the AG off I'm fine with melting one squeegee...

It's like buttering toast, you could get some melted butter and pour it on your toast, but chances are some of the toast would be saturated and some toast would be dry. Or you could use a stick of butter and a knife to spread a nice even coat on the whole thing.

PS I also polished some of the panel with mother's mag polish. It looked nice and shiny, but when I put it on my OHP the projection didn't look any better.

Its amazing how some of the LCDs are like newborn kids and others like my Westinghouse take more punishment. I unwittingly beat on the thing and it works like a champ! maybe I just got lucky?

None of the scratches show up in the pictures so I think I now have two useable 15" panels. Maybe I will build a second PJ!

I was going to pay ScreenTek to do mine, the guy I talked to Friday didn't want to do it because they didn't have a Sharp WUXGA in stock incase they broke mine durring the re-polarization, he says that happens sometimes. That makes me wonder exactly how they strip the panels.

Finally I have a little progress to report. Last Sunday I built the frame work for the light engine part of my projector.

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I bought a 14" band saw Monday and spent a couple hours a day Tuesday, Wednesday, and Thursday putting it together, to cut the 1/8" thick aluminum plates to shield the heat and light. Tonight I cut and drilled the plate to mount the pro reflector holder to the inside top surface of the light engine. I'll have to work on cutting the plates for the other sides later this weekend.

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Here is a shetch in progress of the projector I'm building, incase you were wondering what it will probably look like.

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I've been looking at the various wiring diagrams for the electronic balast, the black one. In the various diagrams made by different people the wires are different colors. My balast wires, facing the end, are black and red on the left and two blue wires on the right.

Does the red and black go to the 120V AC and the two blues go the bulb or is it the reverse?

Take a look at this thread is says red/black is input blue/blue is output. Check the pics to see if this is similar to yours.

cheers,
gs

Thanks much!! Thats exactly what I need! I searched a long while but that page never came up for me.

I've almost got the light engine finished, I gotta try to find some high temp. spray paint then mount the bulb and do a test burn.

Thanks again.

Weekend Update. I've finished cutting the aluminium plates and have temporarly set them up in the completed framework, along with the light. I've got to figure out how to mark the plate to drill the holes to attach the mogul. Then I can do a test burn.

This view is from the bottom.

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This is from the side.

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In both views the engine is sitting on it's face.

Looking good on the new stuff man, but hold the phone... is the triplet on the bottom?

EDIT: Oh yeah, btw, where do you get those fan grills to hold the reflector?

Thanks.

I beleive I got the fan grills at Newegg.com

Hey there MM.
Nice work so far.
(love that carbon fibre)
Have you read ColdSteeles upsidown build in the folded forum??
Here is a link...ColdSteeles upsidown
He,along with Elken found that the "salts" inside the lamps hang around at the bottom of the lamp,and interfere with the image when using an upsidown config.
Hope this helps.
Cheers P

Hello pun15her. Thanks.

I had not read his post before, I have just finished reading it through. I have seen a few small pieces rattling around in my bulb there is some whiteish fog on one side of the filiment, on the side with the long support rod.

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The edges are a little blurry, trying to shoot through a curved piece of wavy glass will do that.

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ColdSteel's post refered to the salts redistributing after it cools down. If I were to do a test burn for a few hours with the bulb vertical, would that keep the stains down in the frosted end?

My design is mostly set in stone now so I can't change my bulb orientation. But this problem does concern me now. I'm going to a lot of trouble and expence to try to make sure I can get the best quality image I can get. I would hate it if the light source became the problem, thats not so easy to fix.

Thanks for pointing me the link. It also helped answer a few other questions I've had, mostly about fresnel spacing, and LCD to mirror distance. Mine is going to be unsplit so it might differ from his slightly. I going to be using the PJ in my bedroom, sitting on wall shelf above my bed. The distance the wall/screen is probably only going to be about 8 feet or so giving me a 60"-65" screen.

I'm still not sure exactly how tall my PJ is going to be, the distance from the shelf to the celing is about 31"-32" so it can't be taller than that. Since it's above my bed I dont want the lens to stick out to far either, so I don't hit it with my head when I'm in bed. I've got a bit of balancing act, not to tall, not to deep, not to heavy.

Just a thought Matrix Man if you secure every thng in your build you could just flip the PJ over so your lamp is on yhe bottom.

RR

Matrix,, nice build..

but I hate to be the bearer of bad tidings, but the uside down is a failure, in one single thing only

The salts form a pool, at low side of lamp, and are an essential function of lamps operation, in that this pool is what is known as the cold spot, and this pool is the supply for the lamp life, it becomes fluid, but stays there, even at full run temperature
It also inteferes with the amount of light and the colour temp of your projected image immensly, especially the colour.

I personally luv the upie downie style, has so many advantages,, but!!

one solution is to somehow side shift the lamp and reflect with a mirror at 45 degress,, but it would have to be a mirror the can stand very high temps..

on another note, your pro reflector will not survive at all above lamp, so be prepared for its fauilure, the coating will tarnish and go mottled..from heat.

Unfortunatly it is a necessity. I have a celing fan with a light almost directly in the path of the beam. Having the bulb at the top and the lens at the bottom is vital to getting below the fan.

I've got an extended hot mirror on order from Edmund Scientific about 4" X 5", but that won't reflect the light.

Man, thats not good at all. :angry: I've given myself two weeks to get the build done, after working fast and furious the past week and a half I've almost got the light engine done.

I haven't read about anyone elses vertical failing in that way. Are you sure about the reflector failing? I thought it was made to withstand the heat?

Look try it,, your lamp may not have lots of pooling,,,, it works,,, but I am a purist when it comes to colour of projection, and was unhappy with result,,, just because it was there

so complete the task,,,, however the reflector,,, hmmmmm that will be affected, for sure,,,, so keep an eye on it now I never had a fan directly behind it to try and keep temp down, as I dont like direct airflow over lamps, as they need temp to run properly..

What if I left the mirror in place and angled the bulb a little so the pool would be toward one end. Then made a rectangular flat shaped duct to direct air flow behind the pro reflector.

Has anyone tried that before?

Everything is worth trying,, I would say now that you have gone this far run as is,,, see what you are dealing with first then proceed with mods,,

but run without pro reflector at first too,,, or buy a spare one,, they do work well if setup right..

I found this today on Edmund's site.

http://www.edmundoptics.com/onlinecatalog/...00&search=1

I wonder if getting the 4X5 45° cold mirror and offsetting the bulb would work well. It only seems to have 90% reflectivity in the visibal spectrum, I wonder if that loss would be a lot less than the pooling in the bulb?

Hey Matrix,, sorry did not mean to slow your build,, mods can be added,, get it fired first,,

just wanted prewarn you is all..

have a cruise thru my plog the vertical one,,,

No problem.

My problem is I need it right the first time, this PJ will be come my permanent TV, so once it's built and functioning well I won't want to change anything. Especially if it will mean that the PJ will be down more than a few hours for mods. Better to get it right now than later when I get lazy. I'll try to find your plog and have a look.

I got my hot mirror today from Edmunds as well as more hardware from McMaster Carr. I placed an order today for a cold mirror from Edmunds. I will try elken2004's suggestion about shifting the bulb to the side and bouncing the light at a 45° angle.

Would I need to raise the 220mm fresnel closer to the source or is the mirror now concidered the source? I also wonder if I need to block the light of the shifted bulb to the fresnels? Would that cause a shadow in my image? If I add a lens after the hot mirror, would it improve the brightness any to refocus the light to a sharp point on the 45° mirror or does the light need to be a larger spot? Too many questions, not enough experience.

Now I have to figure out how to mount the hot mirror as well as the cold mirror. I hope this works.

I've lost count of the thousands I've spent so far.

Here is a quick sketch of my redesign.

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Matrix the focal lenght still comes from arc to fesnel

I got my cold mirror from Edmund Scientific today, now I have a hot mirror as well as a cold mirror. Both 4"X5" I'm planning to modify my light engine, by shifting the bulb over and mounting the cold mirror at 45° where the bulb use to be. I was going to use the hot mirror as well but I might try it without. The specs. say it has a temp range of 50°F to 450°F so I would think it would be ok without a hot mirror.

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The cold mirror passes 80% IR and reflects 90% visible. When I hold it up to the light it looks blue when I angle it, it turns red. Neat.

I'm not sure if I need to block the light of the bulb from below, now that it is off center. I'm not sure if the light being off center will affect the fresnel lenes much. I may need some kind of light gate.

I will be watching this build carefully. I'm just starting a straight shooter and wanted to do the upsidedown thing after but saw the salt problems.

Keep it up! This will be great.

Question: Why are you using a cold mirror (expensive) rather a good FS mirror and hot mirror after?

It was mainly a personal choice. I needed something I knew could stand up to the heat as well as be of high quality. I know Edmund Scientific sells good stuff even if it is high $$. I'm way behind my self imposed schedule so I didn't want to spend a lot of time trying to find a cheaper mirror that could also stand up to the heat. I also bought an extended hot mirror from Edmunds, almost twice the price of the cold mirror, $220 + next day shipping. I may still use the hot mirror, but as of now, to save some time, I'll just try and go with the cold mirror and hope it keeps enough heat away from the rest of the system.

Matrix,, when you fire this new config up,

I believe you will be the first to harness the full vertical config,

as also the normal vert, lamp at bottom has an inherrent flaw too..

only when using a reflector of course and especially when using the pro reflector, because the reflected light feeds back thru the molten pool on bottom of lamp, which in turn contaminates the purirty of colour..

I weighed up buying a mirror, but opted for rebuild, mainly because I was chasing other spectral issues,,

I started work again for a couple hours Friday afternoon, all night Saturday night until about 5am Sunday morning.

I got the mounting fixture for the 45° cold mirror and the bracket to hold the pro reflector designed Friday afternoon and started construction on it Saturday night. I did a test fit of the pro reflector bracket and the cold mirror frame early Sunday morning, I should have taken some pictures but at 4am I wasn't thinking. The cold mirror frame seems to work pretty well.

I went to bed about 6am this morning and got up around 10am, I spent all afternoon working on putting the pieces together. I'm attaching some pictures of the assembly test fit. I didn't install the cold mirror in the frame, I didn't want to risk breaking it. In the pictures the light engine is sitting upside down. Hopfully I will soon be able to do a test burn.

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One more, I ran out of space in my previous post. The file size limit in the fourm is too limiting.

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Minor update, I added the cold mirror to the frame to see what it looked like.

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I put the mirror in backward becaue I'm leaving the plastic film on untill I'm ready to use it.

Another update today.

The UPS guy brought my LCD panels today, I sent them last week to be repolarized with high gloss anti-reflection film. It only took the company that did it an hour to do all three, they boxed them up and shipped them out the same day. I wish I hadn't screwed one of them up back when I tried to remove the anti-glare film myself. I should have waited, I could have saved myself a lot of trouble.

I think I'm about in the home stretch as far as my light engine goes. I cut the outside panels this afternoon I've got them temporarly taped in place with masking tape. I'll be using small thumb screws to attach them to the frame work. That will make it easy to quickly remove the panels to make adjustment and such.

The edges are no where near a white as they look in the picture, the flash did it. The edges look light grey, I'll probably try to use black paint to color the edges to help them blend in better.

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Great work so far,Matrix.
As Elken said,your work-around should purify the reflectors output,although the introduction of the mirror will cost you,to a minor degree.
But I am looking foreward to seeing the results,she will be an impressive piece of work,well done.
Cheers P