NEC 8.4" Transflective Solution - Custom Kit

**changeip** · 09-11-2007, 11:47 AM

Those 2 links above look like the actual PWM circuit used to control the LEDs, but not the LEDs themselves. Did you run across anywhere that states the actual LED assembly they are using ? Some day we will get to the bottom of this stupid, overpriced, complicated method of getting a bright LCD in your car : )

Sam

**thermoptic** · 09-11-2007, 01:52 PM

Turbocad6, that is an IMPRESSIVE viewing angle! I wish they offered an 8.4" solution.

Changeip, if you look closer on the first link, you will see that they offer both driver and LED rails. The SFR3658 is the LED rail (no datasheet available), but it should fit in the NEC 8.4" 84LHS06 holder. This rail is driven by the SFDLB3676 (75 mA output), but maybe the SFDLB3631 (100mA output) could be used to drive the rail to increase brightness? I need the specs on the SFR3658.

I submitted a sales inquiry to ERG regarding the items above. They offer single quantity items in their online store, but not these products. It appears they are providing 8.4" and 10.4" LED kits as suitable drop-in replacements for NEC and Sharp panels.

**changeip** · 09-11-2007, 01:58 PM

nice - i am very interested in finding out what you find out : )

I've got a LCD LED backlight coming in the mail now as well... waiting to see how this one works and will report back when i get them. It shows 5000nits for a 7" size. 24 leds I believe.

http://h1x.com/permanent/SSB-CEL15890UWW-24.pdf

Sam

**turbocad6** · 09-11-2007, 02:15 PM

I tried to get a 16 bulb inverter from erg... they are not very responsive from what I've seen & was never able to get it.

a lot of these guys are more into trying to get an oem to pick up there product, & have no interest in selling single units, sometimes I approach as a fleet operations manager for my company & I want to buy one sample, with promise of a possible future contract. a hobbiest has much less chance of even getting a reply most times

**thermoptic** · 09-12-2007, 02:20 AM

Changeip, with 5,000 nits you may need some sunblock.

I saw that unit on Digikey for around $40. What driver do you plan to use? What is the cost? Will you have thermal issues?

I was happy to learn of the ECR equation from the Rugged PC Review. I would like to know the reflectivity rating for the MicroTouch ClearTek II or the Elo IntelliTouch SAW touchscreen surfaces. The ClearTek has a an Anti-Glare (AG) coating, which diffuses light, while what is really needed is the Anti-Reflective (AR) coating, which cancels the reflected light. It appears that this is custom optical work.

The 8.4" NEC panel spec states it has an AR coating but doesn't state a hard reflectivity rating. Using data from the article, with let's say it has a reflectivity of 1% (half of normal untreated panel). The naked surface of the glass touchscreen would be 4% for top and 4% for bottom. This yields a total reflectivity of 9%.

For the stock 8.4", the ECR would be 1 + (600 / (10000 x 0.09)) = 1.6:1.

For the 8.4" with upgraded 5,000 nit backlight, the ECR would be 1 + (5000 / (10000 x 0.09)) = 6.5:1.

The viability of the upgrade would depend on the ST-NLT technology and where it will start to wash out. This is why I am reluctant to use too much back lighting. With a default CR of 600:1 on the 8.4", I'm thinking it would fare well with double, maybe triple the luminosity. Is there a rule of thumb here with current contrast ratio and max brightness limits?

I just don't look forward to a DIY backlight project with custom housing. This is why the ERG solution was so promising. Optical bonding would drop the reflectivity to 4% so ECR = 1 + (600 / (10,000 x 0.04)) = 2.5:1. The 5000 nit would be 12.5:1. Keep in mind that I am a total greenhorn and my reflectivity numbers could be way off.

Turbocad6, I should create an OEM integrator shell website, say Thermoptic Industries International, with one of the cheap hosting companies, a few clicks deep, with a pay-as-you go mobile number. Request a plant tour and on-site visit up front, but only after you have reviewed purchased sample to verify their competence. You know, before you serious consider them for the 1K/month kiosk production ramp.

**thermoptic** · 09-12-2007, 03:55 AM

Well, well, well! What do you know! Look what Future Electronics is selling for $378 in single unit quantities:

http://www.componentsuperstore.com/s...cturerName=NEC

I ordered one, after quadruple-checking the part number. I will have it by Friday or Monday at the latest. They will have 61 in stock once my order ships.

Now it's time to decide on whether I purchase the stock inverter or locate a suitable bright LED backlight and driver. Decisions, decisions...

**thermoptic** · 09-12-2007, 04:26 AM

It appears they also offer the 6.5" NL10276BC13-01C for $375.19 in single quantity but it is currently not in stock:

http://www.componentsuperstore.com/s...cturerName=NEC

**DarquePervert** · 09-12-2007, 08:57 AM

Hey thermoptic....
I've been casually watching this thread, since I'm at a point where the next (and last!) major component for my setup is the LCD touchscreen.

I was perusing the datasheet specs for the NL8060BC21-03 that you ordered and I have some questions, if you don't mind...

It says that there is no inverter supplied. What is the inverter used for? Backlight? Something else?
Where could an inverter be obtained that would be appropriate for this LCD, assuming one is actually needed?

Also, am I reading this correctly that it is only an LCD panel and no touchscreen? Installing a touchscreen is a pretty simple operation, methinks. I've seen writeups & pictorial how-to articles (thanks, Armen!) and I'm pretty sure I could pull this off with no problem.

If this is a nifty super-bright daylight-readable screen with minimal glare (or at least less glare than a stock Lilli or Xenarc), it might be worth the DIY factor.

**turbocad6** · 09-12-2007, 09:59 AM

dp, the inverter is the power supply for the ccfl backlight & is necissary.

also, I've seen mention of those led strips being 5,000 nit's & worrying about it being too bright, well just fyi, that rating is the light itself directly measured, but when placed in an lcd the lcd itself blocks/absorbs the majority of this light, a lcd brightness measured after passing thru the panel is aprox only 10% of that, the lcd itself will block around 90% of the available backlight, which is why super bright is needed for an end result that's pretty bright.

a 5,000 nit backlight with all taken into acount would give an end result of aprox 500 nit screen, & these #'s can vary slightly depending on the optics & diffusers used in the panel, add a touchscreen & you may be looking at an end result of less than 400 nit screen. it would be nice though if you could just drop one of these in & have a 5,000 nit screen, now wouldn't it

**thermoptic** · 09-12-2007, 11:21 AM

Turbocad6, in my haste to achieve a better ECR, I plugged in the raw nit value. This was wrong!

What was I thinking?

Before I pursue the LED upgrade option, I need the raw nit value of the stock backlight. Maybe I would would need 15,000 nits to make a dent? If I go too high, I will need to switch to a liquid cooled solution.

I received a response from ERG. They will deal in single quantity. I will get specs for the LED rail and driver. Hopefully they can provide the brightness rating of the backlights for both the NEC 8.4" and 6.5" models?