thermoptic

spmclaugh, no worries, whore all you want The more information, the better. I saw you were active during the initial transflective upgrades. Glad to see you have returned.

I purchased the 8.4” NL8060BC21-03, which uses CCFL and requires an inverter. I saw that the SR-NLT required the switch, so I opted for the ST-NLT model, which does not.

For the LVDS cable, I recall reading that Motorcity stated that soldering cables to the small pitch HiRose connector was out. He had an expensive crimper for the job.

BTW, I would really appreciate your take on IR touchscreens. Pros, cons, favorite manufacturers, etc. I am tracking my touchscreen quest here:

http://www.mp3car.com/vbulletin/1118176-post6.html

Thanks in advance.

spmclaugh

I mentioned that I'm involved in a project where we are interfacing directly with a TTL/LVDS display, and we just chose the NEC with CCFL also. We are leaning towards the smaller model though. Good catch on the 'R' versus 'T'. We are probably just going to design our own inverter, I think.


Yea, I think they're 1 mm pitch or something. Definitely beyond my abilty, though there are probably some old-timers I know that could do it. I'm starting to appreciate paying money for a clean & easy connector... I just spent a week molding and casting a power connector for my HID headlights. Never again.


Well, they are usually (slightly) lower resolution, so you wouldn't want to use them in some kind of tablet PC with a stylus (for handwriting). And of course, they're a little more expensive.

Also, since the sensors are probably at least 5mm from the screen surface, you get a little parallax error if you use it from an angle. In other words, if your finger is going at an angle, the X & Y coordinates where the beam is broken are not the same as the coordinates where you touch the surface of the screen. But a human finger is already unwieldy enough that I don't think it matters. Everything else about them pure benefits... You can't get a more clear image -- there is nothing but air between you and the screen.

It works kind of like the safety beams on garage doors. Just a bunch of light sources & photo detectors. Break the beam, the photo detector notices, and it tells the computer where you touched.

As far as brands, I didn't do any comparisons. The IRTouch brand from Digikey are the only touchscreens I looked at. I couldn't find many distributors for these things. I'll look a little more tonight and tomorrow, because our project team may be finalizing our decision in the next 24 hours.

thermoptic

I had the dog leashed for the evening walk, passing through dining room, and I notice a box on the floor near the wall . . . . wait, what the . . . it appears the Wife forgot to tell me about a FedEx delivery today I look at the box . . . dog looks at the box . . . dog looks at me staring at the box . . . "yo, it can wait" he says

[ 45 minutes later ]

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thermoptic

Side and Top Views:

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thermoptic

Here is a close-up on the connector. The CCFL is housed in a tray and slides out, for quick and easy replacement I suppose?

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spmclaugh

Nice. Is the LCD connector surface mounted or through-hole? The ghetto-fabrication side of me can't help asking. I'm getting ideas which involve the CNC PCB milling machine in our lab...

thermoptic

They're all SM. With this form-factor, I would expect everything to be SM. Here's a few cropped images which give the side profile and the top view with clear shot of the pads.

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thermoptic

My LCD research is winding down. I found the Avnet Industrial LCD Solutions Guide to be informative. At 100 pages and 3.8MB, you'll want to save and view separately in stand-alone Adobe Reader. Great review of touchscreens, optical enhancements, and displays.

Avnet Industrial LCD Solutions 2006

Note that Page 37 starts the touchscreen section. Page 67 starts the industrial display solutions. On page 70, I was pleased to see a range of brightness values based on ambient sunlight values of 10K, 30K, and 80K NITS for transflective displays. Hopefully more manufactures will start to list this data as transflective devices become more established and more competitive in the market. An ECR listing would also be nice.

spmclaugh

You're lucky to have had that option w/ the FPD group. I don't suppose you'd want to open it up and try to figure out what components have been modified in the optical stack...? I probably wouldn't if I had paid good money, but it can't hurt to ask! To get anything meaningful though, it'd probably take a whole bunch of individual tests on each layer of the stack -- a lot of time.

thermoptic

Note 3 on page 7 of the NL8060BC21-03 spec warns of UV exposure. The AR-coated polarizer has a surface hardness of 2H. If I opt for the IRTOUCH 8.4" K-series with no glass, then I will want to find a suitable protection film that hopefully does not require optical bonding. The 3M Prestige Series PR 70 clear UV film might meet this need.

3M Prestige Series Overview
http://www.3m.com/us/arch_construct/.../products.html

3M Prestige Series PR 70
http://multimedia.mmm.com/mws/mediaw...NNnChyyJmmmml-

Has anyone used this product? I'll bet we can get free samples!

thermoptic

I received a follow-up "qualifier" e-mail from ERG. They wanted contact information and project details in order to route me to the appropriate sales representative, so hopefully not the "Trash" folder rep.

I stated that I am a member of a technical LCD/Display design forum, where we compare, upgrade, and tear down products. Informed them of optical stack work, water-cooled LED backlight projects, custom LVDS controllers,etc. I threw in competitor names and stated that we rank high in Google searches due to the rich, technical keyword content. GoogleBot already found this thread. Geez, it is all knowing...

I didn't provide the link to here, but I told them the Google hits would give them visibility beyond this forum and expand to Kiosk developers, etc. If their specs are not under NDA, hopefully they will bite. As turbocad6, stated, this will be a drop in replacement with probably no significant gain. I am hoping to get raw NIT values to compare against the stock NIT brightness of the NEC, which they may know as well. Perhaps I could spin a PCB express board with double the LED density in a rail strip, then leverage a higher powered driver. Ehh, do I really want to pursue this option, better to wait until I juice the current stock solution and evaluate its performance.

I briefly researched CCFL lighting. The NEC has two CCFL, but I was wondering if I could upgrade the bulb strength? Are all CCFL bulbs the same in terms of brightness? I imagine you could have higher quality phosphor coatings, and such.

Selecting CCFL Lamps
http://www.lcdparts.net/howto/selectccfl.aspx

CCFL Lamps
http://www.lcdparts.net/CCFL1.aspx

Maybe drive them a little hotter. The inverter driver may step-in once the voltage or current thresholds have been exceeded. spmclaugh, you mentioned rolling your own inverter. What needs are you addressing (i.e. better efficiency)? Can you comment on CCFL bulb quality?

And from the folks at ERG:

Selecting an LCD Backlight Driver
http://www.electronicproducts.com/Sh...g.jan2007.html

thermoptic

I reviewed the NEC 84PW041 inverter specs in more detail and it offers a fixed pot to control brightness or variable voltage interface (0 - 2.5V) for brightness control. The LVDS-07 interface card on the EPIA can't control the inverter, it can only route the 5V to power it. Thus I would be stuck with setting the pot to max and hope the ST-NLT tech works its magic. Nighttime viewing may be to bright...

A better, and more masochistic , approach would be to spin a small photo-detector circuit. Brief searches yielded the following:

TSL254R: LIGHT-TO-VOLTAGE OPTICAL SENSOR
http://www.taosinc.com/images/produc...SL254R-e12.PDF

I should be able to connect this directly to the inverter, as the VOUT voltage is proportional to light intensity. Response times appear to be fast enough.

The sensor sensitivity would determine if we need only one or an array to determine if the brightness really needs modification (i.e. sun hitting top corner only). The transflective properties of the ST-NLT panel will control the brightness adjustment automatically, so perhaps only the day/night detection is required. I need to see it in action first...

For the near term, I really need to get the cable length measurements to Duayn so he can get started. I will get the LVDS-07 EPIA card and 84PW041 inverter by Tuesday, but won't be able to view the panel...

BTW, Duayn stated the IRTOUCH units make for a clean bezel, so I may be able to Dremel out the double-din area a bit for the 8.4" dimension, sand, and then paint, with no fiberglass work. That would be SWEET!

spmclaugh

I don't know how much they can or can't do with phosphors, etc. Something to look into more. I've never really bothered much, because I figured I'd just use longer tubes / more tubes.

If you look at Cd per meter (Mouser's catalog for example), the tubes' output are pretty similar with regards to diameter. (Cd / m^2 does vary with diameter, because a fatter tube has more surface area. Better to look at output per unit length.)


You could probably drive them a little harder, if you're willing to replace them more often (electrodes will wear out). As far as building an inverter, I wouldn't really recommend it unless you have a reason. The team from our project talked about it more, and we might even go with ERG. The original reason was to get maximum efficiency, customizability, and simply because we were already "on a roll" building other things custom. But for the price ERG charges, it's probably worth the time saved.

bryon01

I'm in the process of buying the 6.5inch XGA NEC display for a totally different purpose than what you guys are doing, but it boils down to needing an outdoor readable display so here I am.

(Long time lurker, never posted before, this forum has great tech info by the way and I have used the info here numerous times)

I contacted NEC directly and was sent to a distributor. The rep has been very helpful and also mentioned that they (them or NEC, not entirely sure) have bonded 90% transmissive A/R coated capacitive touchscreens to the 6.5" display and that the price was nominal (150$ for the bonding+ touch screen cost) I will post more once I learn more to give back to you guys but this screen seems to be an awesome package for 375$ roughly w/ XGA resolution.

I also read the warnings of UV exposure and will try to find out more from the rep about possible damage. I find it odd that a display marketed for outdoor use would not have a safeguard against normal UV exposure. It defeats the purpose to have an A/R surface if I have to lay down another film on top of it.

thermoptic

byron1, welcome to the thread and thanks for posting. The more information we share the, stronger we all become...

Who was the distributor? Does the $375 cover everything? Based on my very limited research, bonding would cost $300 with a variable $100 to $150 "prototype" tooling fee which covered bond material matching, and such. Do they offer this with 8.4", or did you just get really lucky with your target dimensions??

For UV protection you want soda lime glass. See my touchscreen thread in the Input Devices sub-forum. Don't know if the capactives use this type of glass. See Wikipedia for details.

I think the optimal solution is 3-6 mm soda lime glass optically bonded with multi-layer AR coatings (five is best). You then attach an IR touchscreen on top. Serious coin!