LCD panels

Hey all,

I've been having some difficulty in obtaining a panel that I want without spending heaps. (I was looking for the nView Z115 and Z215 but neither are readily available to Australia) So I am now considering getting an LCD monitor and ripping the backlight out, or getting an electritian to do it. But I noticed these replacement lcd panels (see pic) and wondered if they could be connected into a computer and used like that. Could they? If not, what else would be needed? If so, what else would be needed? ... :xeye:
Yeah, so if anyone could help, that'd be great.
Thanks
 

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"Morien that looks like a laptop display and without an expensive several hundred dollar driver board it will not work"
Yup....:(
Or else we all would be using them. Imagine 1280x1024 32bit color display poly STN (super twisted nematic) which gives way superior contrast as it goes beyond 90o twist like TN and gives a more absolute black as th e result. Not to mention the poly which makes it more transmisive in the pasive stage----ahhhhhhhhhh ewwwwwwww eeeeeee.:D I'm making myself drool, but anyhow its missing what tells the lcd grids to turn on or off as to twist and pass light throught the second polarizer sheet. PC screens and tft are multiplex which is run by ics to control the banks simultaniously. These avg. lcd's are TN (twisted nematic). The LC (liquid crystal) twists the light as to pass second polarizing filter. When its not twisted you get black. Variences between and 3 sub pixels (Red green blue) make up for all the colors. 0v is twisted as to pass light, like how you cn see through panel when its off....The avg. start to twist at 1v and go to 5v max before saturation of color into next pixel from what I understand. Its quite complicated and driver boards arent interchangable between dif. lcd's. This is why they are $.

Hope that helped explain why that isnt what you want. Know if it had all the driver boards you would still need to do some hacking as laptop panels connection is a ribbon. You would need to seperate all the signals and I dont think they are the same as a CRT vga mon. So that would make for some rewiring also. Its really not worth the problems. Its actually easier to get the hole mon. But the there is the $ and if you mess up $ waisted and then again most cant have the nacklight removed or its chip on glass type lcd which is like imposible to use for this. All in all not a risk I'm taking.:bawling:
 
Sure you could do that. If the laptop had the power (cpu mhz) and ram enuff to run tv/dvd video. Then the desktop could serve it the data through a ethernet or seriel connection. I would recomend ethernet myself, like 100mbps. Thats what I got here between my pc's and I can serve movies to the other, dvd at that with no frame loss. Plus my main pc has a tv tuner card so the other pc can do it all too. That would be the harder route though. And I think it would cost as much $ to get a decent lappy as it would to get a used lcd mon. A 15" lcd mon. used isnt that much in comparison. Can prob. get one used for about $150 or so. New around here the 15" lcd's arent that much but it varys greatly place to place. Best of all these lcd's are getting cheaper every day. Only 1/4th of the panels produced are good enuff to be used. The rest are "recycled". CRT's even have a lower success rate thus the expense. So the good panels have to make up for all the flops by raising the cost....LCD's are getting better at manufac. and quality which passes the savings on to us. Lots of new fab methods being tried out. Sooner or later ones gonna drop the market price on these lcds significantly.
 
Most backlights are removable via bending some metal tabs, or are simply glued/taped on. There is no way to hook it up with a controller, being that it needs a huge amount of data. For an example, a 640x480x12 LCD would need exactly that multipled, probably 60 times per second(depending on LCD, they are usually 60). If it is a split panel, then it will need the top half of the panel and the bottom half sent at the time, which makes for a even more complex controller. A few people have successfully created CLPD/FGPA logic for contolling LCD. OpenCores.Org has a full VGA controller with Analog and LCD output for free. www.earthlcd.com has some controllers, I believe for < $250 that will work with a large majority of TFT panels.
 
For $250 you should just get another LCD mon and tear it apart. About the same cost and you KNOW the controler will work. When I was saying about backlights I dont mean normal LCD tv's and such. I ment lcd pc mon.s. Most of those are dang near impossible to get apart and if you do they are very frail. The ribbons are usually to short and some are chip on glass, where the controler chip is embeded in the glass. So you cant change the backlight on those chip on glass ones. Its a chance you take untill you find a model that works, then stick with it.;)
 

the whiner

Disabled Account
2002-10-07 11:27 am
yugoslavia
I know there were many discussions about this, but I am still convinced it is possible to connect laptop’s LCD screen to desktop PC!

How?

I don’t know, but this could be the ways to do it:

1. To buy special controller to do the job (200-300$, too much).
2. To buy sage s9330 display processor or something like that (I don’t know the price, but probably still too much $’s).
3. I’m not sure, but if there are some CRT monitors that convert analog signal to digital, maybe it is possible to take such electronics (from broken monitor) and to use it as A/D converter.
4. Maybe it is possible to take digital signal from desktop’s video card, somewhere between GPU and digital/analog converter, and to lead it to LCD! I THINK IT WOULD BE THE MOST PROMISING AND CHEAPEST WAY TO DO IT!

Also, in first three ways there would be D/A and A/D conversion, and significant lost in signal, but in fourth way connection would be completely digital.
 

the whiner

Disabled Account
2002-10-07 11:27 am
yugoslavia
Why should you mess with it?

1. I bought broken laptop for 50$, I sold HD, CD-ROM and adapter for 100$, and now I have LCD and 50$ :)
2. Laptop’s LCD have much better specs than projection panel (which costs >200$)
3. Laptop’s LCD have polarisers etc., and it is much easier to build lighting device for it than for projection panel. If you look at laptop’s LCD, you will see that lighting tube is placed at one side of it, and screen is lighted evenly all over its surface, without hotspots etc. So, i think it could be lighted even with fluorescent light, without need to use reflectors, fresnels, etc!
4. Even if you are not making projector with such screen, this way you can get LCD desktop monitor for free!


I don’t have such knowledge in electronics to do this myself, so help is needed here!
Also, if you have pinouts or datasheets of video cards and laptop LCD’s, feel free to share them !
 
The polarizers in a laptop are no dif then a portable lcd tv. Prob. is they dont convert the polarity just reflect it, well the film does. Then the lcd polarizers which they all have (wouldnt work without!) absorb the wrong polarity making heat and dimmer pic. The reason a laptop is lit from side but apears evenly lit is also like lcd tv's. They use a prism film and light pipe to spread the light evenly. Does about the same as a fres. just side to front not front to back... So the polarization not only takes a polarity reflective film to work, but also relys on a sealed tight, close reflector also, as it uses the reflector to bounce the beam around untill light polarity changes. Then the film passes it. This is called light recycling.;)
 
lcd panels NEC & Sharop + others

I alos found
www.guadrangleproducts.com

they seem to have a large amount of different sets to hook up panels (you know the one that were on ebay for 1 penny ( the nec nl6448ac33-18 and the sharp LQ10D32A... both look very similar anyway i bought them form some misses on Ebay some months ago.

I am gonna call quadrangle in the morning and find out how much of my arm and leg they charge for the set.
 

remp

Disabled Account
2001-11-13 5:19 am
New Zealand
Just thinking out loud about how to interface a lcd panel with no driver board to a video card. As many know there are hundreds of panels available cheap without driver boards. Good specs too.

Some video cards put out analogue only most of us I guess, but some put out analogue and digital to prepare the way for full digital between the computer and the monitor when ever that happens.

I read this somewhere but all thats required assuming you have a video board which puts out dvi then all you need to hook up to a LCD panel with no driver is a compatible "receiver board".

Assuming this is true you have a video card doing most of the heavy duty digital work, puts that out on the dvi outlet and you find a receiver that mates with the LCD panel so the video card and the LCD can communicate

Sorry if I pinching somebody here's info. Dont mean to.

Be worth checking how much for a video card with DVI included
If thats at all reasonable
Next step look into receiver boards and what panels they support
and how much they cost.

Its a round a bout way to get an LCD panel but worth investigating because ebay projection panels are starting to get very expensive.
 

remp

Disabled Account
2001-11-13 5:19 am
New Zealand
uvodee

Thats amazing processing power. Not too expensive either.

Point is all LCD's work on digital signals.

The projection panels we buy have an analogue front end so we can hook them up to an analogue source such as video in which is analogue, or connect them to our computer which is usually analogue. Then the panel changes the analogue info into digital.

A video card with digital out can communicate directly with the digital input of a lcd that has no analogue driver board so step one sounds ok.

Now we need a "receiver card which takes the digital from the video card and makes it suitable for the LCD panel. Thats the bit we don't know about at present. The receiver card.
 

remp

Disabled Account
2001-11-13 5:19 am
New Zealand
I did a google search for lcd receiver

Many lcd's with tv receivers but two links which help along the way.

Here is a link showing an IBM LCD panel with a receiver mounted
on the back of an LCD panel. Its nothing special just a line drawing showing a box stuck on the back of an LCD. First time I have seen anything like a receiver.

www.pc.ibm.com/qtechinfo/ MIGR-4KCPEG.html?up=unknownuser


This link is asking for some transmitter/receiver boards. Maybe that person could be contacted by email for more info. Might have some transmitter/receiver boards for sale. Or perhaps help with some information.
www.eio.com/public/lcd.1998/0645.html

It is possible we need a bit more than a video card with digital out. This last link talks about a transmitter board as well as a receiver board.

Since I don't know very much at all about driving a LCD that has no driver board its a bit hard to undrstand the information but one thing is for sure, There are good panels to be had, you can buy a ready made driver board for $200 - $250. What we need is to find a cheaper way to do it.
 
No, there is no way to hook up a controllerless LCD with a DVI port. Not without a lot of electronics. As for pinouts, I can probably get them for you, but they won't do you anygood. You will have probably 4 or 8 data bits, a frame start, a data latch pulse, and a data shift pulse. Plus your grounds, driving voltage, and occasionsally a LCD off pin. There is no way just to hook it up to a parallel, seriel, or ISA expansion slot, as it requires too much bandwidth. Specifically it requires the horizontal resolution times the verticale resolution time the color depth. Just for an example 320x200x8, QVGA. Most of your LCD's require that this data be transmitted 60 times a second. So you have, just for that little baby screen, 30Mb/s. There isn't a way of taking a "digital" signal to drive the LCD directly off of most video cards, as most video chipsets don't provide the nessacary(sp) lines to drive a LCD. If you have a older Chips and Technogoly video card, you might be able to drive a LCD off of it. However your LCD configuration data is generally stored with the video BIOS, and you would have to find a way to hack the BIOS to the point where it would work with your specific LCD.

DiVX( or rather DiVX ;-)) is a high compression lossy video codec based off of MPEG4. It isn't made to copy DVDs, it just often is used in copies because of it's extremely efficient copies. It can very easily exceed VCD quality(which is a terrible MPEG1 compression). DVI is a digital video interface, that can provide both analog and digital video, depending on which DVI interface you have. It doesn't generate LCD timing signals.