thanh510

My lilliput 619 over the years has started to dim quite a bit. It went to the point where it was pratically unreadable in all conditions during the day.

So I decided to upgrade. I took out the existing cathode and here's what it looks like. The picture makes the cathode look really bright but it's not! PARTS of the darn thing is burned OUT! I guess after years and years of abuse from being in the extreme conditions of the car, it just couldn't withstand it any longer.




I got this LEDs strip from superbrightled. It is about the same width as our LCD panel.




http://superbrightleds.com/specs/FLS.htm

About 1200 mcd/2, should be a huge improvement.






I removed everything, then started cutting holes in the plastic frame and the white liner. The holes are just big enough to have the LED part of the strip to stick in. This will also allow the LED to remain flush and allow me to utilize the metal frame to secure the led in place without any glue or tape.

I didnt take any before pictures but here's the after.

Without LCD.


Uniform light? or Bleeds:


As you can see the light is slightly not uniform. However, it's very minimal. You'll barely notice it during normal operations at night or during the day. You only see it when the screen is all black and it's not even all that bad!


With LCD.


Talk about a significant improvement!

Now, to adjust the brightness for night viewing. It's will be just too bright at night. There's 2 options to adjust the brightness of LEDS. First is to lower the voltage. Which will do fine in most cases but there's a limit to how low you can go. If you go out of the operating voltage, you will get nothing. The second option is to use a controller and drive the led with pulse. You might even increase the brightness in the process. http://www.ledsmagazine.com/news/5/5/11.

They sell controllers to do this or you may create your own custom microcontroller device (which I may just do) but that will be later.



What do ya think?

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nobb

Very interested in how this will perform in the sun. Ive been meaning to do an LED upgrade project too.

thanh510

The screen performs tremendously better during the day. It's pretty cloudy today, so I can't really compare it to a really sunny day. I will put it in my car as soon as I have it all together. My compartment needs a little repair but I will get to it as soon as I have time.

- Typical glare from touchscreen unit. Will bond an anti glare to the touch when I get my hands on anti glare stuff.

All in all, I say there's a significant improvement over the old cathodes. I says this might be even better than the newer Lilliput LED touchscreen because I potentially have an limitless dimming potential and full brightness without wash out colors. ( I just remember using the lilliput leds at night and it's blinding, even with the settings lowered. My eyes weren't the same after that). And it seems to have similar brightness during the day. However, I don't currently have a Lilliput led on hand to compare (doing it via memory).

Curiosity

Nice. That looks like a good improvement. So is it the 30 LED strip? 12V seems like an easy replacement.

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thanh510

I used the 30 LED strip with cool white. 1200 mcd/2! However, I was only able to put 21 LED in there. The LED strip can be cut every 3-LED segments.

nobb

Wow, Im having trouble visualizing just 21 leds being brighter than the stock CCFL tube (which is blinding). Is it really that bad at night-time? I have the CCFL EBY701 which has the same lcd panel as the 619 and I find the brightness is just perfect. Not too bright for night, but bright enough for the daytime. My plan was to have two sets of led strips, one on the top, one on the bottom. The top strip would always be on and the bottom strip would be controlled by a photo sensor, such that the bottom strip only turns on when it's bright out.

thanh510

It really depends. My 619 is really old. 5-6 years?

The EBY701 has a rating of 400 mcd/2. That's pretty bright. I believe mines had less. And Cathodes degrade overtime, whereas LED does not.

So after 5-6 years my LCD backlit is pretty much toast.

LEDS has tremendous benefits over Cathodes too. It takes less LED to produce the same amount of brightness. It uses less wattage also. So 21 LEDs might pretty much be overkill in a production environment but considering my LCD is made for cathodes, it should be plenty.

I came across a few 629 LED units a while back ago. They are only rated for 300mcd/2 and IMO these suckers were too bright at night (at medium setting, the lower settings were just awful when it comes to PQ). Maybe the 629 LED adjusted the brightness artificially and kept the LED operating at max brightness. Which explains the washed out PQ on Max Settings. Max settings probably just allowed the LCD to pass more light through, all while sacrificing color.

This is a 20 dollar solution to replacing your backlit vs buying a new unit with all the bells and whistles for 300. Or Buying a LCD with Cathode unit for 150.

Curiosity

Mine might be older. LOL The only thing holding me back is I have the inverter powered off the dash lights at night. It ranges from 7V to 10V. The LEDs probably cut out under 9V. That could be a problem. When I do MOSFET PWMs they tend to get slow on the low end too and the flicker would drive me nuts.

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GPS DirectShow Filter / XOBD / MiniCam

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Kosti

Great Mod!

durwood

I think I will have to do this to mine since it is about 5-6 years old, but mine has never really been readable in sunlight. Did you mean 1200mcd instead of lumens? 1200lumes is like a 100W incandescent bulb, I think you would go blind starring at that sucker. Nice idea.

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thanh510

Fixed. I was getting quite dizzy looking at these LEDs directly.

piotr

Very cool hack. If you're looking to make an LED controller, check out the PICAXE, they use basic are are super easy to program.

Punky

write up a tutorial! so many people would love this!
I've got a few questions:
- which color did you get? cool white?
- is there any other brighter alternative? would brighter be too bright?
- any voltage adjustment required?
- would these side way LED work better?
http://www.ledlightsworld.com/side-v...eds-p-133.html

thanh510

-I got cool white.
-Brighter alternative are too large for the width of the screen. Although, these LEDs are the only one I tried so far. And there is no such thing as too bright.
-No voltage adjustment required at all. The voltage range is between 9-14 volts. Just plug and play.
-Sideway LED would not work. Sideway LED would just take more space and will require different ways to mount the LED. The current LED I have lay flush to the housing.


Sunlight with Touchscreen:




Direct sunlight from rear.


Other than the glare, the screen is much more visible during the day. Significant improvements from my old half-burnt cathodes! FYI Iphone pics does not do any justice.

If I remove the Touch, I am pretty sure the screen is very readable during the day. Maybe a capacitive touch will finish this project off.

nobb

Judging by the sunlight pics, I think the stock CCFL screen in the newer Lilliputs (such as the eby701) is brighter. Might be worth it to go with 2 sets of the LED strips instead. One on top, one on bottom. Your old tubes must have been very terrible.

Is there any reason why you went with cool white instead of natural white? The cool white might be a bit too blue-ish.

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