black bars leave banding on LCD projector

[Briz vegas]

Hi guys

I have a 2 year old Hitachi PJ tx 10 LCD 16X9 projector which has used not much more than a quarter of its lamp life (I watch mostly one, at most two movies a week only).

Recently I have noticed that if I watch the really wide screen - 2.35 :1 movie or a 4:3 movie and then watch a 16 by 9 format program that there are bands of a different shade where the black part of the of the previous show were. Its sort of like =black burn in however it has gone when I use the projector again a week later.

I thought burn in did not happen with LCD. Has anyone had this experience and is something to do with the projector or the bulb getting older. Of course I hope to get the full 2,000 hours out of the bulb if it lasts the eight years it will take to rack up that sort of hours.

[George Bellefontaine]

I've owned 3 different lcd projectors and have never seen what you described. Sorry. Maybe someone else here can answer your question. However, I really don't think it is a lamp problem. LCD doesn't get burn-in per se, but if widescreen projectors are used a lot in 4:3 mode, a lot of the pixels at each side are not getting used and there can be a difference in color shading at the sides when you go to a 16:9. I understand this can be corrected by putting up a bright picture or white field in the 16:9 mode and run that way for awhile. This has never happened to me because I watch very little in the 4:3 mode other than the occasional old B&W classic movie on dvd. The fact that it is correcting itself sort of sounds like what I have described.

[Chris D]

I too have never had a problem with my 16:9 LCD projector, (Panasonic AE700) even when switching back and forth between viewing 4:3 and 16:9. Sorry.

[Brandon B]

First, it should not be permanent burn-in, so don't sweat that, and it has nothing to do with the bulb.

LCDs can suffer image retention if a static image is displayed for many hours. I had not heard of it occurring from viewing a single 2-3 hour movie before though. Is this occurring from just one movie's worth of black bar use?

Where I have seen it (in LCDs which were showing repeating or static images over most of a day), changing to some other source material which filled the whole screen and was either fairly dynamic, or the negative of the retained image (i.e. white bars where the black ones were) made it go away in a couple of hours. I've seen this in quite a few cases as we run projectors in environments where this comes up a lot.

If your PJ is actually doing this in after only a couple of hours of use, though, then I would suspect something in your drive circuitry is not exactly right. You might talk to Hitachi service and see what they think, although I am not sure it is something that could be easily fixed, and not sure if your unit is still under warranty.

A suggestion would be after you watch a non-16;9 movie, leave the projector running with a full screen bright source for 5-10 minutes, i.e. the DVD menu or the projector's built-in splash screen. Turning PJ lamps on and off is a large percentage of what wears them out, so the additional little on time will not have much effect on your eventual lamp life, and it might help the LCD panels to "reset" before you use it the next time.

BB

[Briz vegas]

Brandon
I'll see if this banding happens again and give your suggestion a go. It seems to reset itself as I first noticed it with the bands top and bottom, but the following week I watched an old 4:3 b&w movie and after that the top and bottom bands were gone but there were new bands on the sides. Originally I thought it might have been many movies in 2.35:1 but the 4:3 movie was unusual material for my system and just 2 hours worth left the colouration on the sides.

I am sure that this never happened until recently.