Transflective raw LCD panels - without controllers

spmclaugh · 09-12-2007, 11:02 PM

Hi. It's been forever since I've been on the forums, but I'm getting interested in this stuff again. But now, I'm not afraid to use some of the LCD panels that I had previously thought were too barebones / low-level.

In the last year since I've been on here, I've become interested in analog & digital video interfaces + signal processing. I've made some demo hardware that generates a VGA signal, and I could easily do the same for TTL-type LCD interfaces. In fact, that's what I'm currently doing in a project. Should be done in 1-3 months (there's more to it than just the LCD interface). I'm very confidant that I could also work with LVDS panels. It's a lot simpler than I used to think.

Previously, I did not want to buy an expensive VGA/DVI controller. And back then, LVDS motherboards were rarer, and for some reason, I just never wanted to buy one... Now, I'd probably make a PCI card, or maybe a DVI-LVDS converter... I'm not really interested in making a VGA converter, though I could do it for sure. I could probably even go exotic and use USB or firewire and send individual frames on-demand (wouldn't be good for DVD's though).

***So my question to you all:***

Are there any particular transflective LCD's that you've always wanted to use, but didn't have a controller for? I would even consider *passive* displays for GPS only (no DVD's). I just want a barebones LCD that is cheap and sunlight readable.

spmclaugh · 09-12-2007, 11:08 PM

Two additions to the previous post:

- Size: If someone is interested in using a weird sized LCD, I'd still be willing to help out eventually, but I am personally looking for something 6.5" to 7.5". Maybe 8", but no bigger.

- Source: I'd even be willing to rip the display off some existing product, as long as the product isn't prohibitively expensive. I don't care if I don't get data sheets or product support. But it does have to be transflective, and be at least 640x480.

2k1Toaster · 09-12-2007, 11:34 PM

I think a 6.5" t o 7" screen would be best. How are you planning to get a touchscreen on there? You need to optically bond it to get the most out of transflective.

spmclaugh · 09-13-2007, 02:08 AM

I'm actually considering not using a touchscreen, but it would be infrared if I used one.

I've found a 6.5" on Digikey that I will most likely use, but I just wanted to get some more ideas. Especially devices that I could butcher up for their screens.

spmclaugh · 09-13-2007, 04:29 AM

Ok, some possible "donors" for screens (mostly I just want to find what models of screens these use): Sony U1, Fujitsu Stylistic, Fujitsu LifeBook U1010, the smallest Sony Vaio, something called the Intermec CV30, various kiosk devices... EDIT: And the obvious one that I forgot: OEM/aftermarket car navigation (bypassing the composite video input, if need be).

and some screen part numbers:
- Toshiba LTM025D88 (6.4"), LTM024DB4 (6.1"), LTD089EXWS (8.8")
- NEC NL6448BC20-20 (6.5"), NL6448BC26-09C (8.4")
- Optrex T-51638D084J-FW-A-AB (8.4"), T-51952D065J-FW-A-ACN (6.5")
- Sharp LQ065T9DZ01 (6.5"), LQ088H9DZ01 (8.8")
- Microtips NMTG-F32240JFWHSCW-A (6.0")

Maybe that's enough choices already, now that I stop to think about it... But it'd be great if someone like turbocad will has a few more to add

turbocad6 · 09-16-2007, 02:13 AM

I have that 6.3" panel I mentioned, the toshiba ltm06c310 with transflective upgrade, that's the panel used in the sony u-1 btw, it's a cool screen. the first lcd to reach photo quality image resolution..., not sure if anyone else has reached that yet.

I have a few either optrex or au optronics 8.4" dual bulb really good screens, gotta dig them out & see what they are exactly, don't remember exactly, but bright high viewing angle stuff, they don't come in anything as there just industrial open frame lcd's & expensive though.

I have a fujitsu p1610 with an 8.9" widescreen that's transflective & high res, this is an awsome screen for a car install, I haven't opened it yet to get an lcd # yet, but there good outdoors even with the resistive touchscreen in place.if these screens could be sourced you could try to build a 1280x768 controller for it... sick screen really.

I really think the best way to run this particular screen though is off the fujitsu motherboard it comes with, I'm dying to install this in something..., it's the perfect carpc, core solo, low power , tiny motherboard, just perfect.

pulling a stock navi screen might not be a good option as I think you'd be lucky to even get 640X480, unless that's enough for you.

wanna play with something really cool & inexpensive to play with? why don't you play with pda/smartphone screens?, many are all out reflective instead of just transflective, & 1/4 vga... 4 of them togeather would make a pretty interesting display

or really my thoughts are an auxilary screen for an install. that would be really cool to develop & would sell big time, I bet many would love to add a small aux screen, in the cluster, in the rearview mirror, in the console...

if you could interface the touchscrren too you could also configure it to be the ultimate control panel right from within the pc itself, native to the skin & direct keycommand buttons to like rr or cf, or you could set the skin coordinances of the fusion brain & it could run the skin on that screen, were talking micheal knight meets star trek here, that's what I would play with if I was you

develop this with a screen from like a vx6700 or something & you could make enough to buy any screen you want

put me down for one or 2, maybe I'll trade you an 8.4"

spmclaugh · 09-18-2007, 12:59 AM

Quote: Originally Posted by turbocad6

the toshiba ltm06c310 with transflective upgrade, that's the panel used in the sony u-1 btw, it's a cool screen.

Did you get that transflective upgrade from FPD group too?

Quote: Originally Posted by turbocad6

I have a fujitsu p1610 with an 8.9" widescreen that's transflective & high res, this is an awsome screen for a car install, I haven't opened it yet to get an lcd # yet, but there good outdoors even with the resistive touchscreen in place.if these screens could be sourced you could try to build a 1280x768 controller for it... sick screen really.

I've just been drooling over pictures of that tablet for the last 10 minutes. That's a really nice size to carry around too. I'm not the kind of person that can deal with carrying around a regular size laptop.

Quote: Originally Posted by turbocad6

pulling a stock navi screen might not be a good option as I think you'd be lucky to even get 640X480, unless that's enough for you.

I'd be fine with 640x480 on a 6.5" or smaller screen. But like you said, that would be lucky. In all my searching, I only found one screen (the NEC NL6448BC20 series) that was between 6" to 7", VGA or higher resolution, transflective, and actually in production. So if they don't use that, it probably ain't 640x480, unless it's custom-made / custom-upgraded for the company.

BTW, I should have the NEC I mentioned in 10 days or so. It's the NL6448BC20-20, the brightest one, and it's transflective. We're going with an infrared touchscreen, ERG inverter, and direct LVDS. Probably a bit over $500 shipped. I can see why aftermarket companies charge what they do for consumer-ready transflective displays (with a bezel and a controller). I wouldn't be able to turn a profit on this kind of screen for under a grand.

Quote: Originally Posted by turbocad6

wanna play with something really cool & inexpensive to play with? why don't you play with pda/smartphone screens?, many are all out reflective instead of just transflective, & 1/4 vga... 4 of them togeather would make a pretty interesting display

Putting 4 together has got me thinking. Time to try to find some pictures of the bare screens.

Quote: Originally Posted by turbocad6

or really my thoughts are an auxilary screen for an install. that would be really cool to develop & would sell big time, I bet many would love to add a small aux screen, in the cluster, in the rearview mirror, in the console... (snip)

That sounds like a good project, I could definitely do that. I always thought/assumed that these things already existed, but maybe not daytime viewable? I could even make it wireless, but the extra chip would be $30 or so.

Come to think of it, I wonder how cheaply I could make a rearview cam video flipper. I remember a lot of people looking for that awhile back.

spmclaugh · 09-18-2007, 01:16 AM

Quote: Originally Posted by turbocad6

4 of them togeather would make a pretty interesting display

And think of the possibilities with a motorized retracting mechanism for 4 screens...

On an unrelated note, doesn't AU Optronics make a transflective screen that's the right size for a CarPC? I couldn't find a model number, but Maximus sort of mentioned that they exist (in another thread).

spmclaugh · 09-18-2007, 02:21 AM

Ok, this is potentially BIG news:

Samsung's 7" TMR (transmissive micro reflective) lineup. Completely flew under my radar. Models:

LTP700WV-F01
7" 800x480, 350cd/m^2, LED backlit

LTP700WV-F02
7" 800x480, 350cd/m^2, CCFL backlit

TMR has been mentioned on here at least twice that I know of (LinITX makes a screen with it, and CarTFT's CTF700-H). But I don't think anybody has sourced the raw Samsung panels yet. From some very early research, they look cheap. Real cheap, compared to the NEC transflectives. Even if the review of CarTFT's product wasn't perfect, I'd take B+ performance at 25% of the price. More on this tomorrow...

thermoptic · 09-18-2007, 03:14 AM

Sharp Advanced LCD Technology - July 2007 Information
http://sharp-world.com/products/devi...cd200707_e.pdf

On page 10, Sharp describes their Micro Reflective Structure (MRS) LCD Technology, similar to TMR? Also see Dual Direction Viewing on page 4, and 3-D displays on page 8. Every page is wow...

URL contains "china", so maybe we won't see it for a few years in the states ....

turbocad6 · 09-18-2007, 10:54 AM

au optronics makes a great 8.4" dual bulb industrial screen, really bright but not transflective... I have a few, I'll dig them out eventually to get #'s off it, it has 170x170 deg viewing angles too I think... I haven't seen a transflective, but haven't researched anything in over a year either, soo

I agree, I hate to carry a full size laptop too, I carry that fujitsu every day, click bluetooth & I'm online thru the cellphone... cool piece really, & small, but not too small, eventually I'll build it into something....

what are you talking about with the rear view camera flip? on a composite signal?, man, I'll take a few if you build that

same fore the smartphone screens... that'd be a hit for sure.

spmclaugh · 09-18-2007, 02:46 PM

Quote: Originally Posted by turbocad6

what are you talking about with the rear view camera flip? on a composite signal?, man, I'll take a few if you build that

same fore the smartphone screens... that'd be a hit for sure.

That's what I was thinking - composite video. Sort of a shame, because I'd have to digitize it, flip it, and then convert it back to analog again. Might be better (cheaper) to just put a "flip" control directly onto an auxiliary screen.

Do you think that the average user still has an interest in using "regular" (non-flipping) cameras? In other words, cheaper cameras not really intended for backup camera use. I'd personally spring for the waterproof enclosure, good optics, etc. Maybe it was the mp3car store's infrared camera that used to output a non-flipped image. I can't remember...

BTW, it was a case-modder forum that had me thinking that auxiliary screens were commonplace. Not sunlight viewable though, of course.

turbocad6 · 09-18-2007, 03:38 PM

see, now to me, it's the opposite really, it's not so you can use a cheaper camera, I mean there already are cheap reverse cameras out there, that's not the problem really, it's more when you want a GOOD camera that the problem comes... the best rear view cameras available are still medocre compared to a REALLY good camera. I & others would want this flip so a good high quality camera can be used for reverse. if you can build these you will sell these for sure.

if you can digitize, flip & then back to composite I'll take some

pgasenas · 09-19-2007, 11:49 AM

to spmclaugh : hey, dude, i read all this thread and think i found what i need. You see, now i am trying to get some laptop lcd working, so i need some advice. if youre interested, its LG Philips LP150X05. I know all the pinouts, and enough info. Sure, it is LVDS signalling on it.
So, what i wanted to ask, is where do you get information about signalling and how to interface with panels, if you say you are making controllers for LVDS panels? I thoughto of a project that to put some microcontroller and stream some video data to LVDS transmitter, which would be connected to my panel. How do you think, would it work?

. And one more question, if my panel is ripped from some compaq laptop, wouldnt there be any custom undocumented changes in the interface?

bbalazs · 09-19-2007, 12:06 PM

LVDS: low voltage differential signaling. In laptops, the LVDS drive can be
1. The videochip is able to provide direct LVDS signal.
2. The video provides ordinary 18bit TTL RGB signal, and you can find a transmitter chip on the mainboard (usually near to the video connector).

LVDS is approx. 75MHz
Speaking about laptops, it uses 4 pairs of twisted wires: 3 pair data and one for clock.
For shorter distance there is no need to twist them. Between pairs there is a low resistance (approx. 100 Ohms) for the relatively high current drive.

For custom made solutions the second method is more advisable.
Firstly, there are available vide chips that are quite easy to program, because all the information is available (e.g Chips69000).
The transmitter chip uses red, green and blue bits (usually 6-6-6 or 8-8-8), hsync, vsync, de, pixel clk. On the other side it gives you the lvds signal that you can directly use for driving your lcd panel.