LCD panels

[stoko]

this also might help:

ftp://download.intel.com/design/grap...ts/ds170_2.pdf

ftp://download.intel.com/design/grap...ts/db181_3.pdf

[stoko]

http://www.asiliant.com/69030.htm

[zardoz]

I dont know if these are of any value to anyone...if you can see anything usefull that I'm just looking right past please let me know. I want to build a projector..not stuck on any idea or the other yet. I'm a computer tech by trade but havent done any DIY in this particullar realm. I have a possibillity of getting a beat up old CRT pj from a guy I know...pretty sure the blue is toast ... any thoughts on CRT pj's in general ( off topic I know...perhaps a new thread?)


http://www.lcdspecifications.com/


http://www.nexcom.com/product/ebc/index.htm


Zardoz

[stoko]

check this out:

http://www17.tomshardware.com/graphi...radeon-01.html

http://www.anandtech.com/printarticle.html?i=1298

if i understand it correctly, those video cards have connectors for external TMDS transmitters!

on those connectors we should be able to connect laptop LCDs directly, without any interface or additional hardware!

[stoko]

another thougt, if you buy that motherboard from:

http://www.nexcom.com/product/ebc/ebc562/

you can hook up LCD directly ???

[zardoz]

I got an email from Nexcom today... make of it what you will.

prices, for the EBC-562, 563 and 569 as we discussed. I will follow up with our engineers in Taiwan to get any LCD screen compatibility list we may have available for these products, and get this information to you later on this week:

EBC-562 $399.00

EBC 563R $302.00

EBC 569 $339.00 All prices US bucks FOB Freemont CA plus whatever taxes.

If one of these little boards can enable a DIY'er to try a number of used laptop panels till you find the one that works best then it might be worth the expense.. or is this a great deal? and we're all going to rush out and buy one? If these are a good or great piece of kit what are thoughts on a bulk buy... cheaper by the dozen as they say...

For now tho the search goes on

Zardoz

[Morien]

Mmmmmm,
now we're cooking with gas. Thanks for all the replies everybody.
But just think, 1280x1024 res, 32bit colour, easily and inexpensivley replacement of broken LCDs, still will end up with a large projector, but for what a result! I know that people have previously disregarded the possibility of DIY HDTV projectors, but this is close enough.
Now I'm awaiting the compatibility list. Yay!

[Lifter]

Hopefully I can clear up any confusion about LCD transmission standards. 3 years ago I installed a panel in my car's sun visor. It was a 6.5" color screen I got for $30 and I spent 6 months researching this stuff.

Regular digital LCD systems supposedly can't be more that 18" of cable lenth. I have a sheilded external cable in my setup and it works up to about 7 feet (long enough to reach my trunk where the PC is). Most companies that sell flat panel cables use the centronics 50 pin connector (same as SCSI 2) on one end, and the small weird looking plug on the other (the plug that connects to the back of a bare LCD- different for different models). But some places also use this odd 44 pin external plug. That's what I'm using for my visor (I found the connecters at Fry's electronics). Earth LCD sells controllers that support both.

Now as far as LVDS (Low Voltage Differential System, I believe) goes, there is LVDS technology, and there WAS an attempt at a standard simply called "LVDS". It was used in military wearable computers, hospital equipment, etc. The LVDS standard is dead, but LVDS technology is used in all consumer level digital flat panel systems that require the monitor to be away from the computer (store bought LCD monitors, plasma TVs, etc.). LVDS technology allows a digital signal to travel much further than the 18" limit on regular FP transmission systems (10 meters I believe). LVDS tech is also used for some SCSI harddrive systems (the SCSI system called "LVD" uses the same connecter as the old LVDS flat panel standard). DVI is the current LVDS tech standard, and pretty much THE standard for flat panels now. If you buy a Matrox or ATI card w/ a digital flat panel connecter (29 pin), it's a DVI transmitter. Some of these cards don't have the connector, but they have the capability built in, so all you have to buy is a daughtercard for it. If you buy a NEC 61" plasma TV (meaning your rich), it has a DVI reciever. Another standard was made my Silicon Image, called PanelLink, but I think Silicon Image uses DVI now.

Anyways, there is no bare LCD that "uses LVDS" or anything else for that matter. You can find LCD monitors or Plasma TVs that have an LVDS reciever built into them, but no bare LCDs use it, nor any other long range system (because laptops don't need it).

Here's the deal. You have a nice LCD panel. Great. In most case you'd need a backlight inverter, but since this is for projection, you don't. You do need a custom made INTERNAL cable that plugs into the panel on one end, and has some standard plug on the other end (earth LCD and quadrangle sells these). Then you need a controller card (usually $150 and up). If the source and destination are close, you can buy a custom EXTERNAL cable from earth LCD.

But if it's more than 5 feet or so away, you need a long range transmission system (LVDS technology). You'll have to find a company that will sell you a DVI reciever that can somehow connect to your custom made INTERNAL or EXTERNAL cable. Basically, if you can get a reciever that has a Centronics 50 pin connection, then you just tell Earth LCD the pinout and they'll make the cable for you. And if you go this route, you don't necessarily have to buy a controller card or a transmitter because many standard video cards support DVI. Problem is, I don't know who sells DVI recievers in individual quantities. But it's been a while since I looked.

I'm sure many of you have researched this stuff, and there's not much new here for you, but I hope I helped somebody.

[Lifter]

Originally posted by zardoz
I got an email from Nexcom today... make of it what you will.

prices, for the EBC-562, 563 and 569 as we discussed. I will follow up with our engineers in Taiwan to get any LCD screen compatibility list we may have available for these products, and get this information to you later on this week:

EBC-562 $399.00

EBC 563R $302.00

EBC 569 $339.00 All prices US bucks FOB Freemont CA plus whatever taxes.

If one of these little boards can enable a DIY'er to try a number of used laptop panels till you find the one that works best then it might be worth the expense.. or is this a great deal? and we're all going to rush out and buy one? If these are a good or great piece of kit what are thoughts on a bulk buy... cheaper by the dozen as they say...

For now tho the search goes on

Zardoz

Hate to burst your bubble, but those are just single board computers. Tons of companies sell them. Advantech is a big one. Anyways, all it says is that it supports a DVI interface. Not a big deal. Many popular video cards have that already like Matrox and ATI. My computer I'm on right now (FIC Sabre) has one, as well as the transmitter and 29 pin connecter. And just cause it supports DVI, it still won't work on any laptop panel. You'd need a DVI reciever and a different custom made cable to connect the reciever to the LCD. And that's for ONE individual LCD. You'd have to re-configure the cable or buy a different one for each LCD you try. In fact, that Nexcom board doesn't even have a transmitter built in. It says it "allows external TMDS transmitter (DVI) for advanced panel interfaces". That probably means they sell an addon card that contains a transmitter on it. But you can already get that for regular PC's. My old Voodoo card has one. No need to spend the dough on a SBC.

Point is, don't buy one. By itself it won't enable you to try one LCD, let alone many. And even if you buy the reciever and the cables, you don't need that motherboard- you can just use a normal video card that supports DVI.

[Morien]

POP!
There goes my bubble... I think.

I'm not really knowledgable with this, but with that information in account, will it be possible to plug an LCD panel from a Laptop into a Desktop PC and use it as a panel for projection? What will I need specifically for this? Distance between LCD and PC isn't really an issue as I can get them as close as possible. Also, I will only really be using one LCD panel (recomendations?) and sticking with it, so it doesn't really matter about the compatibility of LCDs.

My design (been modified since my last if any of you remember seeing it) is attached, sorry for the crudeness of it.

As you can see I'm making a self-contained projector-htpc (home theatre personal computer) unit, which is even more bulky I know, but still easily mobile. The reason for it's height is so that I can just have it floor-standing at the wanted height to project the image.
Is my design doable? If the distance between LCD and PC is still too great, I can attach a side unit which will hold the PC in line with the LCD requiring only 5" of wire along with the subwoofer, reciever, etc.