LCD Backlight Upgrade

**Scouse Monkey** · 05-03-2005, 04:16 AM

Originally Posted by dragonBTV

the LED is checper and easy to build for side mount project
the 1W white LED costs $1 and you can simplly add 20 of them with Liliputs Hitachi LCD....

dude. we have looked at all these options - trust me. We have looked at 1,3 and 5W LEDS but they all require cooling or they won't last very long. This cooling is bulky and a lot of people just don't have the room. I for one don't. The 3W LED is the equivalent of 60 normal LEDs but it runs at up to 70 degC and needs a heatsink.

LED backlighting is still not used becasue it is not as straightforward as you think. If you point me to somewhere i can get 1W while LEDS that run cool then please show me as i would love to try them and eliminate the inverters from the solution all together.

**skippy911** · 05-03-2005, 07:22 AM

Originally Posted by jcdillin

Project FAQ

How bright is this going to be?

Well everything right now is a guess, but we are hoping for the 800 to 1000nit range. Untill we get the tubes and test them we really dont know.

Will that brightness be with the touchscreen on?

**Scouse Monkey** · 05-03-2005, 02:56 PM

Originally Posted by skippy911

Will that brightness be with the touchscreen on?

doubt it. TS robs 25% of the brightness. Unlessw e canget 300 orders for new ones that will only rob 8%!!

**Arathranar** · 05-03-2005, 03:01 PM

25% is an underestimate in my opinion. The specs are around 400 nits without TS and 250/280 with (depending where you read them / which LCD make it is). In my opinion it's probably worse since I find the blurring effect the TS has on the LCD makes it a lot less readable on top of just the washout effect the sun has.

**Scouse Monkey** · 05-03-2005, 03:10 PM

yeah the 280 is normally knocked around.

Typical specs for a 4 wire resistive overlay is 75% clarity though. (well thats what 'we' in the touchscreen business use anyway

) Then you have problems with extra glare and the fuzzyness.

**tj!2k4** · 05-03-2005, 04:30 PM

You guys should have a "Project Completion" progress bar or % in the FAQ post

**Scouse Monkey** · 05-03-2005, 04:34 PM

Originally Posted by tj!2k4

You guys should have a "Project Completion" progress bar or % in the FAQ post

good idea but ithink it would be depressing!!!

**tj!2k4** · 05-03-2005, 04:37 PM

oh, i don't think so.. the mere fact that you guys are investigating this..... .brightens up my day =)

**Scouse Monkey** · 05-03-2005, 04:39 PM

hahaha. I am just looking at how to build my LEd backlighting test rig again. i have 100 bright LEDs on the way over from the USA witht he CCFLs. (and yeah it was planned to try it before the above comments about trying LEDS)