Comments on: Repairing an InFocus LP290 Projector, Part 2

By: calvin

calvin — Mon, 19 Sep 2011 05:50:51 +0000

Hi, I have 2 faulty projectors. One is Toshiba TLP 260 and Canon LV-X6.

Toshiba: Image has a blurr spot which is growing. might be faulty polarizer but change is costing me SGD$1000+.

Canon: The left and right side of projected image has different colour. The left is yellow/orange while the right is blue. might be prism faulty but change is also costing me SGD$1000+.

Can anybody help me regarding my problem with a less cost? I have an important presentation this Friday. Would truely appreciate any advice

Thankyouthankyou

By: E. Allen Blackwood

E. Allen Blackwood — Fri, 09 Sep 2011 04:39:17 +0000

Keith,

I found your website a year or so ago, after purchasing a LP290 and realizing the picture was always REALLY blue. I took my LP290 apart and discovered a melted filter that looked nearly the same as the one in your picture. Since then, I was able to procure a broken LP290, and I replaced my filter with one from it, and it worked!

However, here is my problem: now the projected image has one color (green-ish looking) that is misaligned from the others. I guess I must have bumped something or…? Did you ever get your LP290 back together? Did it work fine when you did? Do you (or anyone else that happens to read this) have any idea what I might be able to do in order to fix my picture?

Thanks very much for posting all this, and I would be very appreciative if you were able to get back to me!

-Allen

By: Keith Neufeld

Keith Neufeld — Tue, 08 Mar 2011 11:20:38 +0000

Eric, I would say: The blue polarizer works in conjunction with the blue LCD to create black in the blue channel.

Yes, it’s possible that a plain polarizer (rather than a blue polarizer) would work. Just find one that can withstand the heat, and come back and tell us of your results!

By: Eric

Eric — Tue, 08 Mar 2011 06:12:40 +0000

Forgive me if I get this a bit wrong, I’m new to optics.

If I’m understanding this correctly, the polarizing filter for the blue channel doesn’t actually need to filter blues because that is done upstream via mirrors. The main function of filtering the blue is to help create darker blacks(by filtering whatever the mirrors missed).

I’m asking because I have a burned out blue polarizer and finding another working blue polarizer is a bit difficult/expensive. Regular polarizers are quite cheap however.

By: Eddy See

Eddy See — Mon, 25 Oct 2010 21:24:04 +0000

Hi there,

Need some assistance. I realised that my Panasonic PT-L759 LCD Projector polarized filter melted too after reading some posts here. There happen to have 3, each with different colours when looking into through the flourescent. Can anyone suggest where i could get 1 that is coloured red and another seems to be coloured green. Really need help and appreciate anyone who could recommend where i could get the polarized filter. Another thing, is it possible to use some alcohol or thinner to get rid of the melted filter film and just replace with a new polarised film instead of replacing the entire glass panel as well. Thanks a lot for your assistance

By: Teri

Teri — Wed, 21 Jul 2010 05:51:05 +0000

Keith,
This link is for the LP280 firmware download v1.26 that everyone keeps referring to. Follow the link then scroll all the way down past the useless pdf files of the user manual, reference guide, and ceiling mount instructions to the download link for the firmware.

https://portal.infocus.com/support/Product%20Pages/downloads.aspx?mic=LP280&on=downloads

I know in an earlier post one reader could not get the computer to recognize the the projector via the ps/2 cord or the USB connection, so hopefully this download comes with a ReadMe file explaining how to get it into the projector. Along those lines…do you know if it’s possible to Flash the update via the IR port? Some computers have the IR transmitter and software/stack pre-installed and have the ability to transfer different types of files via IR…would you happen to know if the projector has the capability of receiving such files via the installed IR receivers?

Hope this link is helpful : )

Teri

By: John

John — Tue, 17 Feb 2009 22:52:45 +0000

only thing i can think of (unfortunately) is that it’s either not a blue polariser (just general polariser like on sunglasses?) or the specs are different.

All blue polarisers that i’ve seen so far are orange to the naked eye (like the ones in this page).

By: Abe

Abe — Tue, 17 Feb 2009 22:27:13 +0000

Dave:- I did try to match the orientation of the original filter, but I agree that some experimentation is in order. I’m going to try to rig up a way of testing while it’s apart using a mains light source, then I can try twisting it about.

Dave:- Got the sample from here “http://www.sciencestore.co.uk/StoreOpticalComponents.asp#PolarisingFilm”

By: John

John — Mon, 16 Feb 2009 23:04:39 +0000

Abe: If you could spare a small piece or put me in touch with the plac you got yours from it would be greatly appreciated.

Maybe not all polarisers are created equal? I noticed that some projectors have an IN and OUT polariser, but from what i can see on my projector and the InFocus one on this page, there is only one?

By: Dave

Dave — Mon, 16 Feb 2009 22:47:46 +0000

No, the polarizer material works both ways (e.g., either direction of light going through it). However, most devices seem to like to mount the polarizers at a 45 degree angle. Thus, if you put one in backwards, the alignment is such that it doesn’t cross with the other polarizer, and doesn’t perform the light blocking function (e.g., it acts like it’s not in there).

As for where to get polarizers, back when I was doing commercial optical work, we got ours from Edmund Scientific. Of course, they pretty much deal in surplus materials, so sometimes the things they have vary a bit. On the other hand, their prices are sometimes much better than retail prices.

Dave