Different LCD types: mine = wrong one?

[declined]

I dont consider myself an absolute newbie, but I'm not an expert at all...
I came across this problem: there are two types of lcd
- Transparent lcd's - are transparent - Duh!
- reflective lcd's - reflect the light back
(- transflective lcd's) - combine these two : they do a bit of column A and a bit of column B 🙂

I bought a way too expensive lcd screen a week ago, opened it up and saw a silver coating on the back. First, I was worried, but when I put some light through it and saw the light came out on the back, I was happy. Okay the light was dim but I only used a pocket lamp ( I dunno the correct word )
I am still worried about it because the lcd in my camcorder looks like a transparent slide with moving images on it... and my new lcd looks very dark when its off.

Did I buy a useless lcd? (I am building a normal projector, not an opaque - mirror-style projector) or can this lcd also be used in such a setup? Is it possible to remove this silver backing somehow?

Question to everyone: what does your lcd look like? with/without silver layer?

 

[declined]

correction

correction to my previous post:
its not called transparent but transmissive... okay but I mean the same thing with it 🙂

 

[declined]

SHIBONGG!!!

Wow it's awfully quiet lately on this forum ... scary

BUT! I have some info on ... lcd stuff!!

REFLECTIVE
A smooth silver piece of aluminum foil, bonded to the rear polarizer, that reflects incoming ambient light. Backlighting cannot be used with a reflective LCD

TRANSMISSIVE
An LCD which does not have a reflector or transflector laminated to the rear polarizer. A backlight must be used with this type of LCD configuration.

TRANSFLECTIVE
A type of backing, bonded to the rear polarizer, which enables light to pass through the back as well as reflecting light from the front.

Check out these and also a lotta other lcd related definitions on this site:
http://www.eio.com/lcdglos.htm
Also this one:
http://www.seiko-usa-ecd.com/lcd/glossary.html

one image says more than 1000 words, so:
Reflective type:

An externally hosted image should be here but it was not working when we last tested it.

Transflective type:

An externally hosted image should be here but it was not working when we last tested it.

Transmissive type:

An externally hosted image should be here but it was not working when we last tested it.

Hmm... gues I dont have transmissive... not reflective either... hmm... transflective?
But still: Is it possible to remov this silver backing?

Greetz
Sieg

 

[jvisaria]

I am not sure...but could the reflectiveish (is that a real word?) possible be some sort of polarizer which just reflects light which is not headed the right direction?

If you have a desk lamp or some other spotlight-type light at home, see how much light gets reflected when shined head on, and how much gets reflected if you shine at a heavier angle.

 

[zardoz]

All the screens I have seen personally (more than a couple) were transmissive. They had polarizer's in both config's ie: bonded to the glass or as a seperate sheet, none of them appeared in the slightest bit reflective. There is somewhat of a dimming effect with the polarizer's that I've seen but thats all.

zardoz

 

[zardoz]

declined

I found this today in my travels...dont know how or if it will apply to your sittuation. Maybe you can email the guy and ask what his panel looked like versus yours?

http://www.greenspun.com/bboard/q-and-a-fetch-msg.tcl?msg_id=009oVQ

zardoz

 

[declined]

I did some tests, including dissection of my lcd:

There appeared to be a reflective coating on the back:

First, I didnt want to do this, but I knew that if I wasnt gonna take any risks, I wouldnt get far so I tried to get this layer off. It appeared to be easier than I thought it would be:it just peeled of without problems

This is one really strange silver film... It seems to be reflecting from a certain angle and transparent from another angle... and it's polarising the light as well

I will keep you posted on this...

 

[jvisaria]

maybe it is a polarizer then?
reflects unwanted light back to be recycled?

that would be cool if the rest of us could get ahold of such a device =)

Jay

 

[zardoz]

It does look like a polarizer...allthough none of mine were as reflective as yours appear to be. On my panels the polarizer is 2 sheets of plastic.

zardoz

 

[verbose mustafa]

That film type stuff has been on just about every lcd i have taken apart. Infact, i have tones of it. It is used on the backlight asembly. You will find it on all backlit lcds.

 

[verbose mustafa]

Heres a fun thing to do... cut out two pices and put them over glasses, and proceed to walk down the street. You will walk like your drunk!

 

[declined]

No it certainly isnt on all backlit lcd's! (sorry if that sounded rude)
My two camcorders both havent got this. My uncle's very old stand-alone camcorder lcd also hasn't got that.

About the glasses thing: yea that would be the kinda thing I would do in a lost & boring moment of the day 😎

 

[verbose mustafa]

Ok... i stand corrected... Many lcds have it. I cam up with the glasses becuase i sometimes find i have too much time on my hands...

 

[HanClinto]

The polarizer stuff

I took apart an old burnt-out laptop LCD I had a couple days ago to familiarize myself with LCD's, and I got two sheets of that polarizer stuff, as well as a diffuser, another sortof diffuser, and another thicker plexiglass type diffuser. But yeah, I thought those were mirrors at first until I noticed I could see through them. I noticed it also refracts the light... it's really wierd and I have them by my desk to play with from time to time. 🙂 It's wierd stuff.

--Clint

 

[declined]

If it's the same stuff as I have, you might indeed use them in some sort of sunglasses: I noticed it "bends" the light in an angle, so you could use it to look at people incognito 😎

... hmm might be cool on the beach 😉

 

[zardoz]

Polarized sunglasses are not new...fishermen have used them for years to "see into" water along rivers and such.....try it out. It's actually quite astounding the difference in what you see...without you see the top of the water...with you can sometimes see right to the bottom....


zardoz

 

[verbose mustafa]

hmmm... I'm not too sure these are polerized then, but who knows. If it were not winter i could go the the lake and find out... grrrr...

 

[declined]

Polarized sunglasses are not new...fishermen have used them for years to "see into" water along rivers and such.....try it out. It's actually quite astounding the difference in what you see...without you see the top of the water...with you can sometimes see right to the bottom....

yep my pfotographic-optics teacher brought one of his Polaroid glasses to school today and he put them together with a polarising filter on an overhead projector, so when you turn one it gets pitch black. Cool: first time i saw that with glasses.

... I developed a bad habid the last few weeks: I seem to look out for loose screws on those new overheads from school, when I walk by them in the end of class. 😀 still looking for a decent *glass* fresnel

 

[jvisaria]

i think most fresnels from OHPs are still plastic, just have a glass stage over there.

if you want OHP fresnels i have a few over here i am looking to sell.

 

[declined]

i think most fresnels from OHPs are still plastic, just have a glass stage over there.

if you want OHP fresnels i have a few over here i am looking to sell.

I would totally buy one or two if it wouldn't cost a zillion to ship them to belgium 🙁 🙁