Gentlemen:

My hat's off to each of you for your efforts looking into this idea. Even if it is a long shot our quest has some merit and the work that each of you put in towards, hopefully, our final goal will definately make history at least for the DIY hobbier's here at LL.

Can I get a WOOP WOOP!

On another note, I received a response from that company. Said to give them a call I guess I'll just have to try to wing this.

But what do you think about the PETROLEUM BENZIN idea? I think it is a huge find knowing how the pros take care of this stuff. It's probably how that company does the job anyway. Shouldn't we experiment with the Petroleum Benzin first?

Of course, I'm not suggesting you run out and get some Petroleum Benzin and dump it all over your working LCD, but I am saying we can probably figure out how to use the stuff safely and save the money.

You may just soak the panel in the stuff over night, and when you wake up the job is done. May even preserve the original polarizers. Its also possible the chemical must be very carefully guided away from certain elements of the LCD, or that LCD's can't handle ANY liquids.

It would certainly be simple to just get that company to take care of things, but I was hoping for an end to end DIY solution. I thought you would be too.

Mark.

I've read some more and have discovered that peeling off the polarizers is done in production of the panels all the time. Manufacturers will remove the polarizers to get rid of bubbles and other impurities that show up in quality control.

Here is a cross section of an LCD panel. I suppose that "Brightness enhancement film" may be the viewing angle layer we have been talking about. Or is it missing from this diagram?

Click to view attachment

I think what this illustrates well is that the surface we'd be dealing with is just a sheet of glass, most of the rocket science (being sealed inside) won't be touched. I think this further illustrates just how many layers of stuff the heat must conduct through before it can be removed. It's also neat to see the spacers. I gather they are glass threads or something.

Can anyone say what that thin layer is just below the "Retardation film"? Further, can anyone explain what the "Retardation (compensation)" films are? Or specifically what the "Brightness enhancement film" is?

I am starting to believe this may actually be doable.

Mark.

Googleing "LCD compensation film" brings up info that the film is a viewing angle enhancment film. This we could do without except it may be necessary when tilting a panel to get good focus when keystoning. It is also called "birefringent film".

It also states in one link that contrast and color saturation must be increased to effectively use the film. I wonder if you need a more powerful backlight when using this film? That would imply the film would hinder light transmittance and we might have fairly significant gains with it removed.

Nice! That would be my deduction as well. I just read some pretty heavy stuff on it too. http://www.nitto.com/ Quote:

A typical use of retardation film is to give STN (Super Twisted Nematic) LCDs a greater display capacity by using a multiplexing drive to eliminate the color variation.

It then says:

Retardation film is also used on TFT (Thin Film Transistor) LCDs on the vertical alignment mode in order to help improve viewing angle characteristics.

Why these are seen as different uses, I do not know. This should be investigated.

Other things we need to know:

1. How the "Brightness enhancement film" works or if it exists on our TFT's in the first place.

2. How exactly the "Anti-glare treatment" works. My theory on this is that it is just an inefficient rough surface that disperses the glare into a larger viewing angle, and not an efficient frequency matching optical coating.

3. What is that thin layer on the top of the topmost Glass Substrate.

4. Exactly what would be a safe process to remove all of these layers. Petroleum Benzin is apparently used commercially and is a safe chemical to clean up the glue. Does anyone have some solid information on this?

SIMUL8R: if you call Displaytronix, could you please ask if they are able to remove all of these layers down to the glass substrate, and at what cost? Also, given their experience with the modules, what improvements or problems in our application there may be.

It seems there are a lot of layers here that we don't need. Not to mention the adhesives that hold them together.

Mark.

Tremendous find, Mark. I think we should proceed with Petroleum B.

Might I suggest first we test a dead panel to visually see how the lcd and polarizers react to PB, anyone???

Definately!

I think we should start REALLY small. A working calculator Then we will know roughly wether this stuff dissolves the conductive paths/Bonded Interconnects. And then see if the screen turns on in the end.

And I wonder where on earth you get Petroleum Benzin anyway?

Oh, and apparently Petroleum Benzin is also the preferred chemical for cleaning the polarizers in use as well (not just for glue).

Mark.

It is just benzene or benzine. Readily available.

http://medical-dictionary.thefreedictionary.com/benzine

My bad. It looks like the chemical is Petroleum Benzine.I looked it up in at Wikipedia. There was no "Petroleum Benzine", but rather just "Benzine". Being it is extracted from petroleum, I think you are right DeathRay64. My only concern is that Benzine's other name is "Petroleum Ether", not "Petroleum Benzine". How sure are you that these are the same?

FWIW, benzene is apparently not the same as benzine. Quote from http://en.wikipedia.org/wiki/Benzine:

Benzine should not be confused with benzene. Benzine is a mixture of alkanes, e.g., pentane, hexane, and heptane, where as benzene is a cyclic, aromatic hydrocarbon, C6H6.

Mark.

Apperently the "B+W Kaesemann Polarizer" is the best photographic polarizer you can buy. Unfortunately it costs over $230 US

Sorry, I thought they were all under $100 for sure. So that means that only the cheaper photographic polarizers are practical. The filter factor of these filters are from 2.3 so one of these filters lets in about 43% of the incident light. No data on the crossed transmittance, or efficiency.

That said, the http://www.3dlens.com/polarizer.htm FILM Polarizers look very promising.

The #POA1 and #POA4 models have a published 38% transmittance on their own and two in parallel would have a 30% transmittance. Crossed they have a 0.005% transmittance. Overall a 99.98% efficiency. The color wavelength is 400 to 700nm.

This means that, should the specifications be trusted:

a. The polarizer aspect of our projectors will allow 30% light through. Multiply that by the transmittance of a raw down-to-the-glass-substrate panel and we would have the theoretical transmittance of our finished custom panels.

b. At 0.005% when crossed, 1.65 lumens of 33,000 lumens.

c. The filter will cut out the bottom end of violet and the top end of red. I'm not sure if can be improved upon with other brands. It will not matter though, as I'm sure the RGB values that are needed to pass are within this range.

But honestly, I am sure these are no better than the polarizers in our LCD's. They may be worse. More research is needed.

The #POA1 model is 630mm x 900mm and cut in half will work in any location with a 15" or 17" and possibly larger monitor. These are $55 US each, but you would only need 1.

The #POA4 model is not large enough for a 15" at 210mm x 300mm but can theoretically be placed further down the focus cone as mentioned earlier. These are $9.90 US each.

The 3dlens.com Home Page describes adhesives and other optical treatments but I don't think the #POA1 has any of them. We should find out what layers are involved in the #POA1, though protective layers may be needed.

I am curious about the 3M Innovations Film polarizers. I'd like to know if they make sheet linear transmissive polarizers. We also need to know the efficiencies if they exist. This page describes their transmissive circular polarizer sheets (so close ): http://www.opticalfilters.co.uk/products/s.../polarizers.htm

The above link also really helps explain how a retarder or "Wave Plate" works. It explains roughly how it is able to bend polarized light in a predetermined direction. Thus the material is able to be arranged on the panel in such a way as to bend light out more to the edges. This explains fully why more light is needed with Wave Plates in a monitor application (as DeathRay pointed out): the light is scattered in more directions. But for our application, as Rox put it, less light will be coming straight out of the panel. Therefore less light will hit the collector perpendicular on both axis, a direction that is roughly needed in order to impact the projection lens.

But it seems to me that the light that is lost to this redirection can be not much more than part of how much light can be seen hitting the front half of your box around the projection lens. That is mostly where it would end up. If there is not much light in the front half of your box (not hitting the lens), then this surely cannot be making that big of a difference.

How much is lost to heat in the Wave Plate, or wether the wave plate distorts the optics is another question.

I'll have to look into it some more, but it seems possible that the Wave Plate can only act on light not passing perpendicular on both axis in the first place.

To DeathRay's point that apparently monitors with Wave Plate's need more contrast, maybe in their bending trickery these things adversely effect more than just brightness.

So many questions.

Mark.

ok, but you forgot that the color layer will stop the 2/3 (roughly) of the light as well. So ideally we have already somewhere 10% trasmitancy. (then rest as well the fill factor, this is the black area betwen the pixels... somewhere 92% trasmtancy....)

Been following this thread for a while, very interesting!
I can imagine if all works well we could use a bank of Cold Cathode Fluorescent light tubes for a light engine.(wishful thinking) Or even a great picture using only a 250 watt Metal Halide. The heat problems would be greatly reduced.

so all lcds follow the same layering pattern? (though I would guess maybe not calculators) I have a psone screen I was trying to use for a projector and did something to the ffc so the colors are messed up ..seems to me it was about as transmissive as my 15" one(I read that same thread about someone saying lcds were more trans issive in one firection than the other...and not in the psone or my 15"..did the light bulb thing) ...so, in the interest of science which chemical should I use to try to remove the polarizers? benzene or benzine?, then (assuming the polarizers are totally ruined by removing them so) where can I get films? wal mart? as long as they're not circularly polarizing ones right?

benzene you can find at Lowes along with other neat chemicals like M.E.K. its a solvent.
As for the Polarizers your on your own.

ok guys,, I know i sort of triggered this a few days ago, etc,,

I have been reviewing what I did a year ago,,,


TFT's

backlite side,,, is the smooth face of lcd,, the polariser on this side,, is used to polarise the backlight at one angle,,, the tft junctions twist the molecules to align with the face side polariser+antiglare bond,, depending on voltage level, results in amount of light passed out to viewer controlled by front polariser+antiglare,,

the polarisers are extremely essential to function of lcd,, "missing" you flood all gates with output light,, the red green blue are created by filters in front of each pixel array,,, they are all colourless function Backlight+polarisation+twist+filter+polariser is what gives us our colour display

Now these polarisers (their qaulity is what determines from brand to brand -and they are very very expensive at higher grades)are also very critical to what we call "CR contrast ratio" the better the polariser, the better contrast ratio,,, there are other panel factors in this too..

however,,, the smooth side polariser can be "lost" but you must have polarised light into panel or light would leak plus CR would be lost,,, so removing exsisting polarisers, would mean only having to replace them with others,,,, back to square one,,,
this may also explain why some people have been getting very different results in their PJ's,, differences in polarisers qualities

there are three types of polarisers used,, transmissive , reflective,, and the third forgot for moment

LCD panels are a series of tradeoffs,,,, CR,refresh rates,24 bit (best lcd density)

if you have a fast refresh IE 8-12ms you lose 24bit down to 18bit,, if high cr you lose bit and refresh,,, this tech has finite limit like all the optics and Eballast discussions,, it is all about trade offs within limits of current technology,,

new LCDS (OEDS or something like that) are gonna be plastic based,, barely know much myself,, but layer reductions result brighter display,,, or more transmissive

What this implies is that if you remove the film then both your contrast and saturation should increase.

The polarizer need not be the same size as the lcd. It need only be the size of the triplet. It does not matter where the polarizer is, only that it is in the light path and aligned properly. This means that the "B+W Kaesemann Polarizer" at $230 may be affordable if you can get it in 3.4" widths to put in front of your triplet.

This shows the cost to be about $80, slightly more reasonable. I think the higher cost might be for an assembly with other filters included. Don't know what the difference is.

I wonder if this would work for a triplet polarizer.

Looking back, my wording wasn't too clear. I was trying not to lose that point. But I figure you would still want a large film polarizer for the light engine side, as unless it is a wire filter, will get pretty hot close to the lamp.I went back to the link I found earlier. The price was $79 as you say all of a sudden. I must have somehow pulled up a 10cm diameter model. But I pulled the page from history this morning so I have no idea what happened there Yeah, I just said to multiply the factor because I don't know what it is . By my rough figuring, the color filters will only allow about 30% transmittance. Combined with the polarizers that would give roughly 9% transmittance. This does not factor in the spacers, or glass substrate, or electrodes, or conductor paths, or the quartz etc. In the black screen thread Mississippiman apparently has the exact transmittance curves of the filters. He has not posted them yet, though. These predictions could get so sloppy. It really just needs to be tried.Transflective. Lets a bit of light through from the backlight, and reflects a bit of ambient light as well (Blackberries use transflective).

Here is summary of what I figure you'd get by removing the polarizers:

Upgradeable polarizers (the possibility that contrast ratio and transmittance can be upgraded).

The ability to experiment with any type of polarizer.

The ability to use any size of polarizer.

Much cooler Panel and much improved air cooling of the Panel.

The possibility that removing these (presumed) unnecessary coatings will improve transmittance and/or image quality in our application.

As Elken2004 eluded to, it is possible that one of the ways that LCD's are staggered from each other is simply polarizer quality. Just as certain lines of computers, and processors are bottlenecked, it is possible that shotty polarizers are used on cheaper displays. This would easily spread the gap between the low and high end displays. Enter: marketing.

Mark.

All high quality TFT's will likely use mostly the same layering. I'm not so sure about my calculator suggestion. What we need are panels that use the same glue as well as the same layers.Not sure yet. Right now it is looking like it may have to be benzine (not benzene).We need to decide between Camera or Film polarizers. Not all of the factors are in place yet. If you choose camera filters, then you just go to wall mart or your local camera shop. The film polarizers probably need to be purchased online. I checked out the 3dlens.com selection in an above post. I know there are other stores online though, so this needs more research.

Ultimately, all of this needs to be mulled over a bit longer before I suggest you go for it.

Mark.

http://polarization.com/shop/catalog/index.html is referenced from a few sites on the web for customizing LCD's. They offer sheets of polarizing film that you pay by the length (cut from a 17" wide roll, up to 800 feet long). 60 day money back guarantee as well. Ships in 2 days US, less than 1 week Europe, less than 2 weeks most of the world.

They recommend their polarizers for repairing LCD's with scratches. If they are talking about large LCD's then maybe they have information on how to remove the polarizer.

The specs are 0.002% crossed transmission at 570 nm. The 3dlens.com sheets are 0.005% (no mention of wavelength). Its an improvement but both seem very impressive. It apparently has the same transmission (38% for one sheet). I assume that two sheets in parallel would give 30% transmission (the same as 3dlens.com).

They do mention some blue color distortion, but all in all this seems to be a better and cheaper polarizer than 3dlens.com. 2 feet by 17" sheet would cost $30 US in this stuff.

Mark.

Were you able peel right down to the glass substrate?

If so, was there any residue left over on the glass substrate?

If so, do you feel that residue could have been cleaned off fairly easily with a solvent, or was it quite set in?

Do you feel a working panel would be damaged in any way with the force necessary to peel the polarizer?

Mark.

An Edmund Optics polarizer:

http://www.edmundoptics.com/onlinecatalog/...?productID=1912

I trust these peoples specs:

0.02% crossed average but at 550nm goes down to 0.01%. This makes me wonder if the 3dlens.com and polarization.com added in an extra zero, as the best crossed so far is 0.002% (polarization.com).

27% parallel.

Interesting because it claims to absorb over 99% of UV as well. Wonder if that is normal with these laminated type, or if all Polarizers filter out UV. Seems it would defeat the purpose of the separate UV filter.

Mark.

I started in one corner and very carefully, lifted an edge,,, "on a falt surface"

then used a sharp blade,, xacto ,, combo of light peeling,, and working the xacto along panel at seam (lifted part and glass,,,, it left very little residue,,, easly cleaned off with alcohol,,,,

peeling the antiglare does not work from polariser....


but bear in mind as i have stated some posts back,, it is of no value,, since you need polarisers, for function of TFT gates...

Yes that was misinterpreted... What I was getting at was; if it was true that the film decreases color and contrast it may also affect brightness. It would imply a significant affect on brightness if we found that a brighter backlight was used in conjunction with this film.

In reguard to the benzene/benzine issue; from what I can gather benzene is the pure chemical (an aromatic hydrocarbon C6H6) and benzine is a petroleum distillate containing many components including benzene.

It looks like petroleum benzin is benzine as best I can tell.

Either way take precautions to minimize exposure to benzene or benzine as they are toxic and carcinogenic. Gloves and a well ventilated area are a must.

If anybody actually DOES this, I sure hope it is NOT with an LCD display that they value. I don't think this will bring any benefits personally, I think these films are probably an integral part of the lcd workings. Good luck if anyone decides to do it.

Definately it's a long shot, but one that could prove fruitful. There are plenty of panels out there with bad edge connetors that have lines in the image so they are useless as a display but would be good working candidates to experiment with.

We will be replacing the polarizers with new (possibly better) ones. That is why I have been posting sources for polarizers. Once again, the idea is to have the freedom to choose different brands/sizes of polarizers to see if something out there works better. Additionally, there will be cooling benefits to the panel, as air will now be flowing over the actual glass substrate, while the polarizers will be cooled separately. And, of course the reason all this started: we will see if the anti-glare and other unnecessary layers are effecting the projection adversely.Good to know. We will definitely be using new polarizers and not the originals then.Guaranteed benefits: cooler panel and upgradeability/flexabillity of the polarizers. But yep, everything else is based purely on speculation. We will ideally get this down to an art before any important panels are touched. Thats not to prevent someone from just going for it. They may be laughing, while you and me are left cautiously tinkering with numbers.

There are 5 elements in our display TFT's that are likely not present in commercial transmissive projector TFT's as they are specific to the requirements of a desktop display.

1. Retarders or "Wave Plates". They are designed to give panels a wider viewing angle.

2. Anti-glare treatment. We haven't settled on this, but it seems this might NOT be an optical coating (something that would be found on a commercial projector panel) but a basic reflection "diffuser". Thus, it seems it may not aid in the absorption of more light. Its design may be a hindrance to the overall transmittance of the panel.

3. Protective layer. Thick coating to keep the Glass Substrate safer.

4. Brightness Enhancement layer. Unclear exactly what this is, or if it is present in normal panels. There is little physics going for it in our application. We are providing a light path that passes straight through the panel, something that I don't figure can be improved upon. My bet is this layer works to collimate waves from the diffused backlight. Then the Wave Plates later make up for the collimation.

5. 5 layers of glue. Holds all of these layers together.

Hi Mark, while I like your enthusiam, I complete disagree with your points for doing this. If you or anyone else want to do this, go ahead... if it works in the end I'll join you. Until then I am going to leave this thread asking you all to READ THIS POST.

Hi Lucky_Me. This is causing you grief? Bummer.

I read tony's post. I'm not sure why I was told to read his post? Tony posted to basically ask the same question we are asking: what role can birefringence compensation films be playing in our projectors when not only are we passing collimated light but also have the panel backwards. The answer was unclear then, and it remains unclear now. This is something that our tests will hopefully answer. Why do you make fun of the research?

For our displays, as Brainchild also later answered, the Wave Plates seem to only be used to keep colors accurate when the panel is viewed at an angle. This isn't cut and dry, though, because I have read some things that indicate that polarized light will always show birefringence as a color shift, even if it enters at zero degrees incidence as in our projectors. Again, it needs to be investigated.Why do you completely disagreeing with every reason I have for doing this? Every one of them? My only reasons for doing this are the possibility of:

1. Higher brightness.
2. Higher contrast.
3. Cooler panel.
4. Polarizer upgradeability.



I'm sorry if I come across as interrogating. I just want to get to the bottom of what your specific concerns are relative to each removed component, so we can prepare for them and factor them in to a logical decision on wether to go ahead with this.

Mark.

Ah, see... I knew this was brought up before my time. Gents, it would be foolish to suggest trying this on your own 'Precious' as yet. I think you all know better. Although, Mark is still crunching out numbers and is doing a wonderful job at it I think an actual model, working or not, will determine if we have wasted our time or validated a theory that might have been quite useful to us. Correct me if I’m wrong but I don’t think this has actually been done during LL's existence. Which brings me up to this point. I am willing to provide a working 15" stripped panel that I had first used in a overhead projector. I'ts a cheap model I got from ebay. Seeing that I am incapable of providing any scientific knowledge in all this I think I should put something in for the sake of our goals, I mean why give you rocket scientist's all the glory . Mark, and only if you feel more comfortable with the numbers you come up with I’d like to ask if you can take on this project and run with it. In the meantime, you all continue giving Mark a reason to get to that point .

P.S. I haven't gotten a hold of that company yet cause of work but will soon.

sim

ummmmm,,, restating,, did all this one year ago IE august 2004.....


does not work,,,,, TFT's run wide open,,, period


voltage applied to each gate twists molecules relative to the polariser by percentage,, without polarisers light trhu each pixel is at full gain,,

and there will be no gain in contrast,, the polarisers need to be on glass,, not away, or light leaks everywhere,,, also quality of current polarisers on lcds are of high quality,,, the manaufacturers need this to be so for competive edge over each other
also another point is that the aligment of polarisers is to the thousands of inch of accuracy,, they have to line up perfectly with pixel array plus perfect gap from glass

Reflective Polarizer Brightness Enhancement Films

Vikuiti™ Reflective Polarizer Brightness Enhancement films are thin, reflective polarizer films that increase brightness.



Interesting Information about the topic,

Vikuiti™ Reflective Polarizer Brightness Enhancement films help to manage light in three ways: angle, reflection, and polarization. Through polarization recycling the Vikuiti™ DBEF film reflects the P2 light back into the backlight where it is scrambled into P1 and P2.

*******

Vikuiti™ Dual Brightness Enhancement Film - Diffuse 400 (DBEF-D400)

Vikuiti™ DBEF-D400 film is a diffuse reflective polarizer film that boosts display brightness up to 60% over the entire viewing range (as compared to displays without film).

http://products3.3m.com/catalog/us/en001/e...ler/output_html

http://www.fpdgroup.com/products.php


Can you please provide a general overview of the trioLCD technology?

Our trioLCD technology is a passive enhancement/modification process applied to a standard transmissive LCD display. This process provides a fairly unique proposition in that it turns a normally transmissive display into one which can be used in outdoor applications as a transflective display without any change to the electrical or mechanical characteristics of the display.

We apply this technology to various transmissive displays including those from the manufacturers Sharp, NEC, Samsung, Quanta, Sanyo, Toshiba, CPT, Chi-Mei, Hannstar, LG, PVI, BOE/Hydis -and maybe a couple other manufacturers that may be skipping my mind. That being said, the trioLCD process works better with some screens than others. Generally, those using a PVA, MVA, or other wide viewing angle technology have not taken so kindly to our process as the tranmissivity of the displays are very low to start with (in the 3-5% range compared to that of a normal TN TFT LCD with a transmissivity around 7-10%).

We have had very good results with many of the NEC displays for 5.5" to 10.4", Sanyo/IMES/and sometimes LG in the 12.1 & 13.3" range, and Chi-Mei/CPT in the 15" category. However, every new model display that a manufacturer comes out with seems to have slightly different to completely different optical characteristics -so, the generalities from manufacturer to manufacturer could change with newer models.

Also, in addition to transflectivity, the trioLCD enhancement generally allows for 20-100% increased light throughput from the original backlights due to more efficient flow of light -again, we do not change any of the mechanical or electrical aspects of any of the displays.

One last time, we will be replacing the polarizers. After this I hope this thread gets moderated.The gain in contrast is thought to possibly occur from removing the Wave Plates, not the polarizers (unless we find ones of lower crossed transmittance and higher parallel transmittance). It's only a theory. If you have specific knowledge of Wave Plates, please inform us of exactly why this will not work. It is something we hope to answer.I am standing across the room from my display with a polarizer in my hand. It works (almost) as well as when pressed against the screen.One of our hopes is that the light exiting the panel will be mostly collimated. Polarizers do work to a certain degree at angled incidence.We hope to maintain the current polarizer quality in our design. Should the specs from polarization.com be honest, we have already found polarizers of outstanding quality. Polarizer quality may also be staggered across LCD lines from a given make (as mentioned earlier) to give a larger gap from the low end to the high.When I was a kid, I once took a quick break from watching the Ninja Turtles to take a calculator apart. I had no idea what I was doing, and was able to reassemble a working screen from the parts left in front of me (I probably used bubble gum as the new bonding agent). TFT's are the exact same basic tech. I hope we'll be able to get it close enough.

Thanks for your concerns. I suppose it helps a bit.

Mark.

My take on this explanation is that the very first polarizer the backlight hits is a reflective polarizer. It reflects the off-axis light (called P2 above) back to the backlight, which then scrambles that light randomly and sends it back forward. Each reflection cycle the off-axis light is randomized with 50% on-axis and 50% off-axis light. The 50% on-axis light goes through to the lcd and the 50% off-axis light is reflected to goe through the cycle all over again. Really smart way of handling the waste light. If there were no waste heat generated by light absorption the theoretically the brightness should increase by 100%. However, light losses through this process increases the light by only 60%.

Now, how does that relate to us.

First of all, it puts the enhancement film on the wrong side of the lcd since it is designed to be on the backlight side, and we turn our lcds backwards. Second, it probably absorbs some light in the process. So it may not be needed for our applications. If we removed it then our brightness should increase.

The only possible drawback is that it may supplement the work of the front polarizer (basically, front polarizer cannot doe its job 100%, so this is helping it polarize the P1 light). If that is the case, then the contrast would decrease as we remove it. However, I would suspect that the front polarizer needs no additional help and this could be removed to increase overall brightness some.

Some more information on the retardation/viewing angle compensation film.

This is a quote from the nitto.com buisness report:

"...Until now two or three optical compensation films were
required in order for LCD screens to display uniformly irrespective of
the viewing angle. Our optical compensation film achieves this feat
with just one film, reducing both production costs and processing
requirements."

It sounds like the polarizers generally darken or lighten the image, depending on the viewing angle. These films do something to compensate for that (hence the name, "compensation film").

These may also not be needed, since we are not directly viewing our lcds from different angles. The lcd is being projected onto a wall. While we may view the wall at different angles, the lcd is stationary and the image is always projected at the same angle.

Edit: Kinda think of it as an analogy to hotspots on our highly reflective silver screens. These compensation films probaly scatter the light evenly in all directions, while maintaining their polarization. Without these compensation films, then the lcd should be very bright when viewed head on and decrease in brightness as the viewing angle increases.

In our applications, where many of us orient the lcd perpendicular to the triplet, the higher brightness when viewed head on would be a benefit. Basically, the lcd will always be projecting head-on to the triplet.

OK, from these descriptions I am going to go out on the limb and make a hypothesis for our DIY applications.

If we can remove the films on both sides of the lcd and replace them with one high quality polarizing film (oriented in the right direction, of course), then our brightness, contrast, and saturation should all improve.

In addition, if the polarizing film does not need the light entering perpendicular to direction of travel, then a much smaller film need only be applied at the triplet, as opposed to the screen.

Sooo, who wants to give it a try.

Mark,SIMUL8R, et all involved in this developement.
I think you may have more than one pot boiling at a time and I give you guys alot of credit. I am amazed at how many detractors you have got out of this.
I think if it works and we see even a 20% drop in LCD temp and a marginal increase in picture quality, everyone will want in on it, of course naysayers never give the adventurous credit in the end.

Remember guys TOMATOES were considered poisonous until someone decided to eat a basket full of them in public. So dont be dissmayed, its forward thinking that got us all on this forum in the first place.

'and you have my axe'

I wouldn't expect one person to bare the weight in testing this theory thats why I provided the lcd. If those of you who beleive there is merit in this perhaps someone could provide Petroleum Benzine and others could get together and providing the polarizers. The only real person we need here is a 'Gandalf' to come up with the magic.

The also said we can never travel to the moon and now we are going for Mars.

griff30: Thanks.

Oops, definitely need two polarizers.

SIMUL8TOR: I live in Canada, so it would be pretty hard to get ahold of your LCD. And (almost hilariously) Lucky_Me seems to be the closest DIY'er to me on the map

It is extremely generous of you to risk your display. But I'd rather see it that you are able to easily remove them yourself.

This needs to be done in 3 parts:

1. Figure out how to remove the layers safely and easily.

2. Compare what optical benefits replacement basic sheet polarizers give, if any.

3. Explore alternative polarizers.

We may be able to get this down to a simple process (long shot) and all you'll need is a $35.80 US visit to polarization.com and $10? trip to the hardware store. If we get it right, the solvent may do all the work. Soak in one bath with solvent, peel up the corners, soak again/ peel the corners etc until removed. Zero damaging force required. Then wash in distilled water. What we need to find out is which chemical will not damage the electrical contacts/conuctors (Benzine?), or the substrate sealant.

I was once trying to get the glue from some window pane stamps off with a razor. It took forever, and no matter what I did the stuff just got thinner and uglier, but never came off. Then I tried some sort of gunk removing car glass cleaner on the stuff. I sprayed it on and got stanced with my rag to really go to town on the thing. One wipe and ALL of the glue was gone. It was infomercial ridiculous. I'm hoping to tee up a chemical like THAT for this job.

Enough cheerleading:

Does anyone have any ideas as to what sort of damage liquid or solvents could entail? Could the whole thing be safely dunked? Let us know your experience.

Does anyone know exactly how the FFC's are bonded to the panel?

Does anyone have any ideas as to the process of removing these layers safely?

Does anyone know if the Wave Plates are ever integrated into the Panel, and not simply glued on?

The panels will be significantly more fragile, as the structure of those layers will be gone. So some special handling will likely be in order as well. Does anyone have any suggestions here?

And finally, does anyone see any realistic outrageous consequence to just trying this? I'd rather know now.


In the end, this shouldn't be rocket science at all (but there are a lot of DIY rocket communities).

Mark.

As for "Petroleum Benzine" I still stand by that plain Benzene would work. Even MEK might work. As for Damaging an LCD its not water based and dries very quickly. Thus for either you would want to cut some cloth peices to the size of the screen and place them on the screen and soak them in Benzene or MEK. IN A AREA ABSCENT OF SPARKS, Flame, and or concentrated O2.
The solvent(s) when done will have removed your finish and are oil based not water so they will not damage the panal, unless removing the finish will damage it.
You can get liquids on electronices as long as it completely clean and dried and did not corode the electronics.
I have soaked a video card in Acetone overnight to remove heatsink adhesive, and the card still runs today (nice "giveaway" as previous owner thought he ruined a gf4 card) . Just make sure that tis is dry dry before you try to place it next to a 400 watt bulb. I think even acetone (fingernail polish) would work well for this project. I it makes it easier,just go to a manly Lowes and pick up Acetone. They have all kinds of solvents.
You want we could pay pal some money to fund this?

The theory makes sense to me, however, there's one caveat.

The polarizer needs to be positioned so that there is no lens between it and the LCD. A field fresnel in front of hte LCD will mess with the light polarisation somewhat, depending on the angle that it hits the acrylic. This will result in a few areas getting bright spots, and other areas getting dim spots. If the polariser is the first thing that the light hits when it exits the glass, this will be reduced to as minimal effect as possible.

One thing that I wonder about...

I know that LCDs "twist" the polarised light. Are those "twisting" molecules pre-aligned in the LCD module, or is it just a relative amount that they twist the light?

The reason I wonder is because if they ARE aligned, then there should only need to be 1 polariser, not 2. The LCD material itself is the first polariser.

I too took apart several calculators. Some I reversed the polariser material so that the numbers showed up clear on a black field. (I did the same to one of my old car stereo decks so that instead of poorly illuminated characters on a black field, I got black characters on an illuminated field. The resulting display was much easier to read.) The fact that this involved flipping over the polar filter seemed to indicate to me that the polar orientation was at 45 degrees to horizontal. Or at least that's what made sense to me.

the molecules are random,,, they line up on powerup,,, the applied voltage is what determines the twist

have a look at display as power up occurs

As I understand it, the crystals can only twist one axis of light. All other axis pass straight through. Therefore (in a backlit LCD):

Should you remove the rear polarizer you would see something of an image, but "lit" areas would only seem slightly brighter than what are supposed to be "dark" areas. The dark areas would be as bright as the lit areas minus the amount of light that was on axis to be bent by the crystals. Hope that reads well

If you were to remove just the front polarizer then no image would be resolved at all (but from possible refractive side effects).Hmmm. I don't remember that. I would have thought that everything would be kept perpendicular to the element edges. At least I am pretty sure that is how it works in large LCD's. May end up having to cut angled polarizers, if not.

Mark.

It looks to me that only one plane of light will pass through the panel. This plane is twisted through the panel until it has rotated enough to exit through the polarizer gate on the other side. If the light has fully twisted to be parallel with the exiting polarizer it will pass at full brightness; any lesser twist will result in less transmittance. It is the same principle as when you change the angle between two polarizing filters and you can vary the light transmittance, except that you twist the light plane rather than rotate the polarizers. It's sort of a variable light gate.

An TN LCD twists the light 90º so the polarizers are offset 90º. A STN LCD twists the light plane more than 90º so the polarizers must be set at an angle other than 90º for the light to pass through. It looks like this angle varys depending on the manufacturers so that may complicate things. If we knew that one of the sides polarizer was always placed horizontally or vertically, that would help.

Here is a link to a company that enhances panels for about $350. Perhaps a stripping and polarizer replacement would be significantly cheaper than a full blown enhancment. I wonder what this guy might have to say about the possibility of increasing transmittance if viewing angle is not an issue?

http://www.man-machine.com/lcdbrightnessenhancement.htm

[edit] fixed some mistakes

[/quote]
I have soaked a video card in Acetone overnight to remove heatsink adhesive, and the card still runs today (nice "giveaway" as previous owner thought he ruined a gf4 card) . Just make sure that tis is dry dry before you try to place it next to a 400 watt bulb. I think even acetone (fingernail polish) would work well for this project. I it makes it easier,just go to a manly Lowes and pick up Acetone. They have all kinds of solvents.
You want we could pay pal some money to fund this?

[/quote]

Hold up, acetone, isn't this a bit extreme?

The theory is that if light, polarized along the x-axis, encounters a polarizing filter then you can control the transmittance through the filter simply by orienting it along the x-axis (allowing full transmittance) or along the y-axis (blocking all light) or anywhere in between.

I am pretty sure that you only need one external polarizer. The other polarizer would be the tft panel. The liquid crystal is a polarizing medium. The voltage applied to it will determine the orientation that it is polarized.

However, if they use 2 external polarizing filters then there must be a reason. Maybe, one filter is not enough - too much light leakage. It is hard to tell. Maybe they use weaker polarizing films on each side to increase viewing angle. We just don't know the reason. However, in theory 1 polarizer should do the job.

In practice though...who knows.

If there was only one polarizer, the panel would not have the capability to "totally" block light. The two polarizers block essentially all light when used together. It's the twist of the crystal that is the only pathway through which the light is allowed to pass.

These guy's will repolarize a panel for $60-$80. I wonder if that means both sides?
http://www.lcdrepair.net

[edit] I see now what you are saying Phutton. However I am not sure that the liquid crystal itself is a polarizer [edit:that's not to say that it dosen't display some polarizing characteristics]. If it is a polarizer, I agree you are probably right in that the other polarizer film is probably to block leakage around the crystals thereby making the crystals the only available light path.