LCD Brightness at night

Zip-Lock · 02-21-2003, 10:09 PM

I have major issues with blight LCD’s lighting up the interior of my car at night. On most LCDs you can adjust the brightness, but at night at the lowest brightness setting is still relatively bright and annoying.

What mods can be done to fix this? Perhaps turning off one or more of the backlight tubes?

How about the big boys like Lexis or Infiniti address this problem with their navigation systems? I’m sure their screens aren’t lighting the whole interior of their cars up at night.

jzgt · 02-21-2003, 10:32 PM

What about an OSD? Wouldn't that control the brightness?

As far as OEM Navigation LCDs, that is a good question...maybe it works off of the lights. If the lights are on, the LCD is dimmed. I'll have to look into that...

- Jeff

Zip-Lock · 02-21-2003, 10:38 PM

Quote:

Originally posted by jzgt
[b]What about an OSD? B]

What is OSD?

jzgt · 02-21-2003, 11:39 PM

On Screen Display - Most Controllers have them availible. I have heard of people just hooking up a POT to it. I'd like the ability to dim the screen too...I don't know if the OSD would do what we're trying to achieve. I think Leslie had an OSD with his DennisK setup. I haven't seen Leslie on the board in quite some time.

- Jeff

digitallexus · 02-22-2003, 03:29 AM

Sometimes a video card / driver will have gamma settings. You could possibly pull down the level a bit for night driving.

Try installing powerstrip http://www.entechtaiwan.com/ps.htm, and then look under Color Profiles - > configure. You might be able to adjust brightness and gamma.

It's possible these features only work \with 3D cards, but its worth a try.

I tried it with my laptop and it worked great, but I have GeForce 4.

ddt · 02-22-2003, 03:41 AM

Quote:

Originally posted by jzgt
I have heard of people just hooking up a POT to it.
- Jeff

How exactly (be specific here

) would one do that? This might be just what I need to do.

digitallexus · 02-22-2003, 04:02 AM

I assume this means dialing the backlight inverter voltage up/down with a potentiometer?

This sounds a little dangerous if it is on the output side since we're talking hundreds of volts. Danger. Danger. :-)

Filip · 02-22-2003, 04:08 AM

I'm a dumbass when it comes to electronics (well..for now I am) but:

Don't you just hook up the pot to the power lead of the backlight? Then it would just vary the amount of power going in. How would you knwo what type of pot to get (are they rated by current or voltage, etc)?

Or not? Someone please come educate me.

digitallexus · 02-22-2003, 04:25 AM

well, assuming it works, decreasing the input voltage to the inverter would be much safer since you are only dealing with 12v or less.

Filip · 02-22-2003, 04:32 AM

Ahh sorry, I think you posted faster that I did...

Lets say (hypothetically) that I don't know what an inverter looks like. Would it just be some box right before the backlight? What would you do with the negative side?

Oh, and thanks BTW.

Alphared · 02-22-2003, 09:20 AM

well i'm getting my screen next week (hopefully). If anyone wants I can whip up a little program that'll dim the screen (if its osd) according to time. so its super bright during the day, start to dim when sun starts going down every hour.

Well this is just a theory, have to get my screen before I can test this out.

The other, more electrical engineering method, is to get a photoresister and build a circuit to sense how much light is in the cabin and adjust the screen accordingly.

Software is the cheapest solution

digitallexus · 02-22-2003, 03:38 PM

The OSD is implemented in the LCD controller / firmware. How are you going to control that from software on the PC?

jzgt · 02-23-2003, 11:46 AM

Generally, the OSD is a seperate piece of the puzzle. There are some controllers with it built in and, actually, I've seen inverters with POTS (potentiometer) for dual brightness settings. Check out your controller instructions for details. ZipLock, which controller and panel are you using?

- Jeff

mercury · 02-23-2003, 08:04 PM

I would bet money you can find someone out there who can or maybe you can program a program that when it is a certain time it sets the brightness and contrast to certain settings. If you really wanted to I bet you could do it by date also since winter has shorter days and the such