Now you can be more than thankful; you can contribute. Maybe you could give us some specifics on your panel?

Death, why is it that you and I always cross-post?? Hehe - gr8 minds ...

EDIT: NEWSFLASH. My mother just informed me: fools seldom differ - DOH!

HEHEHE, Thanks Sonic for telling swoozle to post at the other thread, was gonna do that until I saw yours.

BTW, I'm dieing to see your results....COME ON!!!
sim

I've done all the stripping I'm gonna do for a while ... BWAHAHA!!

PS: Oh Chaddy ... Here Chaddy, Chaddy, Chaddy ...
How's the panel coming along? Do you see the depths we are sinking to when lacking more substantive things to say??! Common, give us somethin' to talk about!

I like Nemo. And Jello. .

Mark.

Hi guys,

Has anyone got anywhere near stripping a 15.4" WUXGA panel? You know the ones that Minoten is organising group buys on?

I think JonJandran is going to try it, i think its a big risk on an expensive panel like that. Should be really tested on a defect one first. RobAndJonK do you have a Plog? i need all the help i can get with my WUXGA plog.

No Plog yet, still in middle of a house buying operation... Once done I have a garden for a shed for a workshop for a projector building fragatastic time.

It is an expensive rhing to try on sucha panel... If only we could source a broken one... I'd chip in for the cost of trying it....

:angry: :angry: :angry: :angry:
I'm back and not with good news. I left the Jasco stripper on for 26 hours. When I came back to my horror, the air pockets had grown! I now have 3 very large air pockets running parallel to each other at a 45 degree angle to the panel. They are 2/3 the length of the panel, and are about 1/2 wide each. Each air pocket seems to have a crease in it....a line running the length down the middle of the air pocket. I think it is a fracture in the polarizer. I applied almost no pressure to the putty knife by the way. This is probably what duece985 has as well. I don't think its "grain" as discussed earlier.

Another negative thing I found, is that after 26 hours some of the stripper had dried onto the polarizer, and could not be scraped off. After I cleaned everything up, I put on another coat of stripper and went to bed. Seven hours later I puttyed off the stripper. It seemed to have disolved most of the dry, crusty stripper from before.

Also, the corner of the polarizer started to split when I tried to pull up a corner.
How do you guys suggest I remove the polarizer now? Is there any way to dissolve the sticky glue holding it down first, or do I just have to yank it up, and deal with the sticky glue mess left behind?....like Mikau

I have just been skimming over the discussions about polarizer removal because I never thought I would be taking it off. Also, I can maybe salvage a piece big enough to cover the triplet. Is that still being done? I haven't heard of that in a while.

Chad,, the originator here,,

it worries me having chemicals so long on LCD panel period,,

i would now peel the entire sheet off, completely, but peel from corners only,, do not stress the glass by pulling it up from panel, it will crack for sure,,, peel it carefully back on itself,, and use a sharp blade to asisit it, dont scratch the glass, just tease the join as you peel,,

then clean up glass with wetted tissue with acetone,, if acetone does not work,, use stripper,, but that would only be my last choice,,, to polish glass after cleaning,,, spit on panel,, yeah I said spit,, clean with tissues and polish with tissue's

and if you want buy full sheet of non adhesive polarizer, I think from 3dlens,,,, THE NON adhesive one..

I need to keep up with posts,,

sorry been busy setting up aussie forum lately..


clive..

What grade spit is it that you use, full hoick or the non-volatile frothy? I think we’ll need the full chemical make up of this.

DJ

Chad: Sorry to hear about that, here's some pics of my taking off the antiglare/polar maybe it'll help you. Start at the corner...I used a exacto blade and glided it along a little until I had some of the film to pull. Good luck.
http://www.lumenlab.com/forums/index.php?s...pic=7882&st=806
sim

heheh way off, OT.....

all fully natural chemicals,,, food bits, nicotine from smokes, port (in my case), ummm but dont eat chocolate prior to dribbling,, leaves abrown smear,, looks awful, in projection,,

non volatile,, hehe non frothy type..

you know,, the kind that one drools at night on the pillow,, or could be called slobber type.

cures cuts too,, paper kind....

Ah, gents.....I just strippered off the TAC on the otherside polar. I think I'm getting stripper happy here.......

Chad,
Any chances at a photo ? I think elken has the best plan now... removal of the polarbear. Take his advise on removal. Slow... *real slow* don't crack the LCD or everything is lost...

Replacement polarizer is not a real big deal, but will be another $36.80 from polarization.com. (this is 2ft of polarizer @ $15/ft + shipping)

If you order a Polarizer from 3DLens you will need to order POA1 (630x900) (24.8" x 35.4"), which is $55+shipping, in order to cut a piece large enough to cover the 15" panel with a 45° polarization axis. (you can see my sketch a few posts back)

good luck and keep us up to date.

you are kidding,,,, another 'polar bear'®(elken) bites the dust

the other side???

Sim † do you have † both sides stripped now?

I am gonna be very interested to see how two replacment 'polar bears' ©. are gonna work

try all sets at 45° rotations, and see how it effects projections, especially the second one..

well, I can tell you its probably not the best idea.. I was forced at gunpoint to remove both polarizers from my panel (no, really I was....and let me tell you holding a gun in one hand while trying to remove a polarizer with the other is not easy ) .... anyway... only have cheap polarbears from surplus shed and the picture on the lcd is very washed out, low contrast, have tried every combo of rotations I can think of... have another panel for PJ though, got any ideas why the color washout? compensation film on rear polar maybe?

Yes, sorry about not posting earlier....dam wire came loose again, but I got it soldered now...yes, both sides polar strippered of it's TAC now down to PVA. As far as brightness...still trying to decifer with my eyes. But I was able to turn on all ambient lights in the room and still surf the net. Still I'd have to let this grow on me to tell. It's a bit clearer I give that much.
sim

but your polars are both still on the lcd yes? was your rear one shiny? I mean your polarbear of course.... ?

Yes, both polars still adhesed to the panel, both polars strippered down to PVA. The rear side was already shiny from the TAC, I just decided to take that one off too and, of course, the PVA is still shiny.

I must say at 115" diagonal and with 2 lamps on it's pretty impressive. Looking harder from 8 ft. away I can see the pixels. I think, I've pretty much maxed out my panel as far as transmittancy now.
sim

Did you notice a big improvement when you took off the rear tac? My LCD is oriented such that the rear tac faces the lamp... and the AG faces the triplet. Just trying to figure out which are necessary to remove.

good question, .... anybody ever see any transmittancy factors on TAC ? I have a light meter coming , along with a panel off ebay .... planning on running some tests of everything I can think of light wise.... even though the new panel is a different manufacturer, I will see how much light gets thru my totally bear panel(no polars on either end) I have now and maybe we can come up with some figures

If you had a low contrast monitor let's say a 250 to 1 would it not be a major upgrade to replace both polarizers with the ones from polarizers.com?{ I know this may kill the LCD but I can't rember why}. It may be better to replace both polarizers because they work together. If one is a lot lower spec {the stock rear polar} I see the contrast taking a hit. If this can be done?

If the polarizer from polarizers.com offers higher specs then we should be able to see and measure the increases in contrast. It would still be cheaper than replacing the whole LCD panel. I have a feeling that the only thing wrong with some of the low contrast LCD is they use cheep polarizer.

There was some reason for not removing the rear polar but does that apply to all LCD?

Hi All,
I have a friend who thinks he can get me a few panels to play with so I decided to try another project while Im waiting...

Using the rag method and a four hour soak, I managed to removed the AntiGlare layer from my dogs eyes...



I think she looks about 14% brighter and her contrast to the other dogs is remarkable!
Sorry. I just could not resist!


Happy Halloween All!

SJ

Click to view attachment

Polarized light is polarized light. However, one polarizer's quality will bottleneck the total efficiency.That is my feeling too (to a certain extent).I see no reason why it can't be done. The only problem will be the loss of transmittance due to reflections. If you can get anti-reflective polarizers then that isn't even much of an issue. There are 2 questions that have not yet been completely answered:

1. Can the polarizers work with the panel as long as they are at 90 degrees to each other. That is, does one have to be aligned with the substrate grooves?

2. Does compensation film only have an effect on off normal axis light?

All theory seems to point to yes for both of these questions.

Mark.

well, I can tell you the contrast on my panel seems to have gone to heck with both polars removed, however , it may be due to cheap polars (surplus shed) (lcd is in projector, this is looking thru lcd, projection thru it is minimal) hmmm.... so are you saying that the rear(or at least one) polar may have to be oriented in a certain direction due to grooves on the glass substrate?

oh.... and this is with unsplit optics .... even when I place a polar against the front of the lcd ( I taped polar to the original AG side) and rotate it all over still the pic is way washed out... suggestions? I have pieces from my original polar (all layers except polar stripped off) and the pic looks the same as with the ss polars...

Have you tried a piece of your original polarizer taped to one side, and then dial in on that from the other side with your original polarizer as well? One polarizers quality will bottleneck the other's.

Un-split optics are not ideal for polarizers. This is no different than if the polarizers were still glued to the panel.

Compensation film should only alter off axis light, unless the panel was designed around the compensation film (not likely by my research).

Exactly how washed out is it? Are we talking basically a white screen?

Originally, the rear polarizer (the polarizer ) would have been aligned with the grooves etched into the inside surface of the glass substrate. You cannot see these grooves, but they will likely either run at 90 degrees or 0 degrees or 45 degrees from the panel edges. I see it as unlikely that this will make a difference, but if you can prove it otherwise, you will have thrown a huge amount of data into the crystal theory. Try to set up the polarizers exactly as they came off the panel and see what happens.

Mark.

mmm.. I think I have, I'll try it again though, I might mention that this panel is probably 5 years old and the rear polar was not shiny ....

Ive tried looking thru the lcd with both the optics/MH and with a flourscent bulb, didn't seem to be much different, one cool thing with the ss polars was that if I twist them far enough the picture gets kind of reversed colors...

mmmm... not quite that bad but the projection is unwatchable, none of the colors are very ...deep? and the contrast is way low...

well, all I have left are scraps of polar.... I think they were the titanium AG type

Doesn't matter. If it worked before you pulled them off, and doesn't work when you retrofit them back on, something must be wrong with your alignment or polarizer/analyzer efficiency. You didn't switch to un-split optics at the same time as the panel mod did you?Expected with any analyzer.Find a way to block out the spilt light. This is only a test to figure out if your alignment is a problem.

Mark.

OK I'll give it a a shot this weekend...and when I was talking about scraps I was referring to the fact that I have no idea how they were on in the first place(to test for alignment to glass grooves) ... any chance the compesation film(which if there was any, is long gone by now ;-) could have done something?

This weekend ? .

Theoretically the compensation film will make no difference with collimated light sources. I am pretty confident the problem you are having is due to poor polarizers.

Here is a quick easy test. If you take those polarizers and cross them out in the open up against a lamp, how much light gets though? If it is a good polarizer, basically zero light should get through (100 W lamp). Try combinations of the new polarizer with the original polarizer/analyzer.

Mark.

okly dokly .... yeah, this weekend...I spend too much time down in my "lab" as it is for the wifes taste ;-) ... while I've got your ear and speaking of crossed polars.... how are the polars set up on an lcd to start with? aren't they crossed? or are they parallel? and if I cross mine you can still see the lightbulb...

Usually crossed. Some very fancy display types use other orientations, but it is not likely that anyone here has one of those. The rear polarizer is aligned to the etching.If you were to stand about 6 feet away from a 100W light-bulb you should really not be able to see it if the polarizers are perpendicular to the rays. We are talking about a transmittance of about 0.002% from a top of the line polarizer. Can you make out the shape of the bulb easily, or is it just a very slight glow? Does it appear blue/purple? Does it seem like more like maybe 1-5% of the light is getting through? That would be typical of a low extinction polarizer. Those are unacceptable for LCD use.

Try 2 bits of polarizers from off your panel. It is the polarizers ability to block out that light that defines how good your contrast will be. The standalone transmittance of the polarizer is also a factor. (Crystal efficiency aside, Contrast Ratio is the parallel transmittance divided by the crossed transmittance).

Super High Contrast polarizers have both a high parallel transmittance and a low crossed transmittance (high extinction).

Mark.

hmmm... crossed is what I thought..then why can we look thru an lcd thats not turned on and see thru it pretty well? (about the same as the SS polars crossed ... do the crystals have a normal orientation in the off(no filed applied) state that twists the light a little? I'll try to sneak away for a few minutes tonight and 'speriment.... thanks!

Exactly. The crystals usually rest in an on state (The ends of the helix are twisted 90 degrees from each other, so the light that passes is twisted 90 degrees). My panel is actually the opposite, but I think it is unusual.Be very sneaky. .

Mark.

Mark have you caught the info I left about the 3dlens polar bears© re not getting adhesive type..

Mikyd do your surplus polaizers have any plastic overlay sheets?

IE are they layered? ,, if they have any protective coatings they will give washed out effect, try a small piece soaked in water for about 3 hrs, and see if it will peel,, the 3dlens type will seperate quite well..

the 3dlens ones, have a easily removeable protector,, before removal they give washy image after removal extinction improved, but other side has bonded protecter,,, hehehehhehe back to sqaure one,,, but guess what that will come off, using water soak method,,, ergo again exposing polarizer layer,,,

I have not had enough time to fully check this out with projector, I have been so busy rebuilding my HTPC, and playing with optics

and in the middle of all of this creating an aussie forum,, whew, need more hours per day...

Yes. A few people including yourself have already stated this. I'm at a loss as to why you are finding that adhesive, and TAC layers are washing out the image? Any theories? The polarizers that are used on panels have those layers in place without problems (though SIM has possibly found a slight improvement).

Obviously if the adhesive is not stuck down to something it will be a problem, unless it is perfectly shiny smooth. Further, the 3dlens.com adhesive variety has a lousy crossed transmittance of 1.4%.

We need to be careful that what people are seeing is in fact a factor of the adhesive, and not just the effect of using a lower extinction polarizer. The adhesive polarizer from 3dlens.com gives a maximum theoretical contrast ration of 27:1. The non adhesive variety from them (and this has little to do with the adhesive) has a maximum theoretical contrast ratio of 6000:1. It is no wonder people are finding a drastic loss of quality.

The TAC layer washout has me stumped. Unless it was scratched up, I can't see how it could make a profound difference. The only thing I can come up with is internal reflection. The internal reflection off a PVA to air interface will not be as bad as that from a TAC to air interface. This is because the TAC surface is further from the masks, so reflections have a higher point of trajectory and could could cross over to the next sub-pixel. I can't see how that would be a significant factor at all, though.

Mark.

I'll check on the layers....I can say that a couple of them(5" squares) have a clear edge to them(about 2 mm in width probably)..hmmm.. wonder if I can trick the wife into going shopping by herself ;-)

While the 3dlens.com adhesive polarizers are no good for our purposes, the adhesive polarizers from polarization.com are of a high enough quality for LCD's.

The only reason that I don't recommend using an adhesive polarizer is because we have no way of consistently sticking these things down without bubbles. You only have one shot. Professionals use a vacuum. Second, we couldn't possible get the alignment in one try. Professionals use a template.

Mark.

interestingly enough if you put a polar in a plastic ziplock bag and try dialing you get strange effects, also if you put sticky tape on, you again getting odd effects,,, found this out very in all this enhancement testing,,

with pure bare polarizer you dial light to dark,, but as soon as you have extra surfaces you get colour reversal or other effects,,

its a birefringement effect that is being seen,,,

the piece i have on my trippy still has the plastic layer facing the field fresnel,, which is scuffed,, but that has no effect on projected image,,

i want to test another piece, 'water soaked'© (mark)

and set it up to compare differences
I am waiting for it, meyer2, is sending another offcut from his sheet

Yes, but TAC and polycarbonate are said to have very low birefringence. They will therefore have no effect on polarization.

If the birefringent material is not between the polarizers, it will have zero effect on projection. So the outermost TAC is completely incapable of effecting the projection by birefringence (but for the slight polarization of condenser fresnel in a split setup -which combined with the nearly zero birefringence of TAC or polycarbonate will do basically nothing). I don't feel TAC will display anything significant in the ways of stress birefringence either.

edit are you using the rag technique when you say water soak?

Mark.

nope just dropped it in a bowl,,, but have to wait long enough for it to just peel off clean,, too early it will unzip polar coating in strips, also no grain effect at all, if left to soak long enough

Wha-? . The only way I can get grain is if I soak a stressed polarizer too long with a full dunk. Surely you aren't finding that if grain forms, you can just soak longer and it goes away?

edit Or are you referring to the condition where PVA separates from the backing?

Mark.

Not that this is some big breakthrough, but when I revoved my polarizer I used wax paper under the part I had removed so it didnt stick back to the glass. I found that I had to go back and forth alot from one corner to the other, and I was getting tired of having it stick back to the glass as I went along. I never had any plans to reuse the polarizer so I was not concerned with the wax paper sticking to the back.
Mark

This is a little off topic, but based on your experience with the polarizers, what do you think is the issue with this panel.

http://server24.pronicsolutions.com/~furni...02405apx261.jpg

There are alot of these on ebay for a decent price if a polarizer replacement is what is needed.
Mark

To me that looks like a blemish in the glass substrate layer, cant see it well enough to tell if it is A/G scuffing, does not look like it tho.

not electronic fault, too random..

hardish impact damage maybe, destroying TFT's against colour mask, (physical damage)

I have heard of people getting blotches on their screen with laptops where the keys press up against the screen. So something may have pressed up against the screens at some point. Odd that you say there are a lot of them?

I don't think it would likely be a polarizer problem. For that to get missed, or not corrected in manufacture seems unlikely.

Mark.

I see panels like this on ebay all the time. Some have dark spots, while the other are light spots. The same ebayer must have about 50 of these panels up right now. I just thought that if was from indentations on the polarizer sheet that these could be had for cheap and just replace the polarizer. If this is damage to the glass part of the panel then these would be useless to us. I dont know enough about the panels to make this determination.
Mark