Making LCD Screens Readable in Full Sunlight?

irregular_hero asks: "I'm in the process of constructing a navigation and vehicle-management system based on Linux for a car. The trouble I'm having is finding a suitable screen to be mounted in the dash of the car. It seems that traditional SVGA/XGA LCD screens have a really bad tendency to totally wash out in bright sunlight -- in fact, nearly every screen that I've tried turns jet black in sunlight. Are there any SVGA/XGA LCD screens out there that one can get that are sunlight-readable? Or is there a way to make an existing screen not respond so badly to sunlight?"

Older Apple active matrix displays

[Bravo_Two_Zero]

I don't know that this is particularly helpful, but the older Apple Portable (non-active) and Apple Powerbook active matrix displays worked pretty well in sunlight. I don't know how available they would be at the moment, so it's probably a matter of finding similar technology. That assumes you'd find them suitable for your application. I don't know what options you have if you really need color, though. Maybe this is one of those cases where the plasma displays were really sweet?

The Ipaq Display

[primal39]

The Color reflective thin film transistor (TFT) LCD used in the Compaq ipaq handheld, when backlit, is extraordinarily visible, even in full sunlight. Whether it's feasible to determine if there are any larger and similar screens available commerically, I am not sure, but this may be a starting point....

Re:The Ipaq Display

[CMiYC]

I believe it is because the iPaq employs a frontlight instead of a backlight. The LCD is front reflective and depends on incoming light. Typically VGA LCDs used in Laptops use a backlight and are washed out by incoming light. To combat the problem, they would need to make the backlight brigher than the incoming source (which would be interesting when you're dealing the with the sun), or use a frontlight LCD like the iPaq.

Honeycomb Aluminum

[Perdo]

Use a 1cm thick sheet of 2mm pitch honeycombed aluminum. Off angle viewing is shit but it makes everything readable by cutting glare and light hitting the screen to zero.

There are a couple of places that sell it but they tend to say "let us give you a quote" instead of just having the product at a given price.

It will be shiny when you get it so get some high quality flat black primer and paint it. It is also very fragile so if you so much as rub your finger across it it's ruined. Sort of like the fins of a radiator.

A cost no object project could use honeycomb aramid fiber (kevlar) or carbon fiber but both of those have drawbacks too. The aramid should only be used in a sealed environment because UV will destroy it in a matter of months. The carbon fiber is just extraordinarily expensive. Neither is as thin as the aluminum so the viewing quality will not be as good either.

Hardware hack

[itwerx]

I dunno where you're mounting it, but you can convert to HUD (Heads Up Display) on the cheap with a mirror. Only problems are 1 - inverting the image, and 2 - need more depth for the display as it is now a prism shape rather than flat (display lies flat or on it's side edge facing w/mirror at 45 deg.)
Alternatively you could get a little open frame CRT from a surplus place like TimeLine [digisys.net] (They usually have a wide selection of LCD stuff too if you want to keep experimenting with that).

Re:Hardware hack

[zmooc]

The prism-effect and the inverting can easily be solved by using a periscope-like setup with 2 mirrors.

Flood Lights

[BenTheDewpendent]

Replace the current back lighting system with a flood light.

include a dimmer for night use.

NEC Versa DayLite / LaVie MX2

[Chris Pimlott]

NEC sells a laptop called the Versa DayLite [neccomp.com] (aka the LaVie MX [dynamism.com] in Japan) with a special "reflective LCD" screen that makes it usable outdoors. It also allows it (along with a second internal battery behind the screen) to run up to 8 hours.

On the downside, the screen isn't very good indoors - NEC says it's "suitable for occasional indoor use". The users reviews I've read agree with this. PCWorld also has a review. [pcworld.com]

This is the right technology

[EMIce]

Yes, this is exactly the new technology that PDA's are using. When Palm debuted it's m505 using reflective technology, the press whined and complained how the screen was not as bright as the IIIc. What they missed was that the IIIc tried to attack the sunlight problem by using different approach, a high intensity backlight. It was a big power drain, made the device bulky and was still difficult to read in the sun. By using the reflective technology in the m505 the screen became easier to read in the sun and without a bulky backlight. The new techology uses the sun to increase visibility rather than competing in a losing battle to make the backlight brigher than the sun. This makes for thinner devices that are still plenty bright with minimal backlighting at night. Good stuff, I'm waiting for prices to come down though.

man, ppl are getting lazy

[vukv]

I am assuming the guy is getting paid for his work, could he searched around a bit for more information? use google.com , it helps you find stuff. he obviously needs a custom screen anyway. jesus

Re:man, ppl are getting lazy

[The Hollow Room]

Yeah. They can't even be arsed to answer a question.

Known problem

[heikkile]

I don't know how they do it, but the guys making navigation stuff for boats have been fighting with the same problems for a while. Maybe they have found some good solutions?

Some PDAs have already solved the problem.

[c0wh]

Take a look at the high end Sony Clié models [sony.com].

http://www.sony.com/clie/ [sony.com]

We've used sunlight-readable screens...

[pieterh]

There are screens made by companies like Siemens that work well in daylight. Try Google. [google.com]

We've used 10" and 15" LCDs in kiosks meant for outdoor use. Our supplier added a reflective film that enhances the screens still further. This is apparently possible even on notebook screens.

The downside is that these screens are so bright they can be unreadable at night. Imagine a car headlight shining into your eyes. Also the high intensity causes most colors to wash-out somewhat, especially when looking at the screen from above. Apart from that they are nicely usable indoors.

The awnser to all of your problems

[Beowulf_Boy]

www.mp3car.com go the the BBS, the link is at the bottom of the page.
Let them know lstrunk sent you.
Currently, I'm putting a celeron 300a in my car, with a 4x20 LCD, a numeric keypad, and it runs *ghasp* windows 98 SE with winamp set as shell.
I decided to do that because I was to lazy, and winamp has all the plugins I need for everything.
It boots in about 30 seconds.

check out...

[Wolfger]

Touch Controls, Inc. [touchcontrols.com]
800-848-4385 They have what they call the SunTouch ultra high-bright LCD panels (touch screens!)
This may be exactly what you need.

How to find a good daylight readable LCD

[stinkydog]

1. Drive to a large city.
2. Find a local fried pastry establishment.
3. Make derogatory remarks about the waist (or wife, or daughter) of local law enforcment seat with.
4. Become handcuffed.
5. Look over the seat at the cool display mounted to the dash (SCMODS for you Blues Brothers Fans)

Here is a good choice [aydin-industrial.com] for your project, but it will cost you.

SD

Why LCDs? VFD's work too...

[Anonymous Coward]

LCDs work off of polarized light blockage with a back light or reflective background. This sucks in the daytime--VFD's--vacuum fluorescent displays operate much better in sunlight and an graphic matrix VFD screen can be substituted into a circuit designed for LCD interfacing. They only have maybe around 5 to 8 colors at most, but the way it sounds, you're not looking for some gigantic screen or mind blowing graphics. Noritake's a decent company, and--ah just do a google search for VFD companies.

You need a front lit reflective TFT LCD.

[stienman]

You need a non backlit (reflective) TFT LCD, then you need to get a special plastic overlay that acts as a light pipe. This takes light from around the edges of the screen (from LEDs, CCFTs, etc) and shines it onto the display, which then reflects it back to you.

This same stuff is what is being used by the people making the 'backlight' for the gameboy advance.

You should be able to get this all in one package, but you need to make sure that the LCD is reflective, with lighting coming from the front.

-Adam

Transmissive and reflective

[markmoss]

There are two kinds of LCD: reflective and transmissive. Laptop screens are nearly always transmissive backlit, that is there is a white flourescent light and a grid of red-green-blue filter dots behind it, and electric fields manipulate the liquid crystals to let light pass through in selected sub-pixels. In most office & home conditions this gives much better color, but in competition with the sun, that backlight is bound to lose.

Reflective displays put a mirror behind the LCD. Where a pixel is on, incident light passes through the LCD, is reflected off the mirror, and passes through again. Where a pixel is off, the light is blocked. Most reflective displays are cheap ones in calculators, hand-held games, gas pumps, etc. These are monochrome and with fairly poor contrast all the time. But there are better ones, and it _is_ possible for them to work in direct sunlight, if they are made with enough light blocking capability to stop even sunlight. It also needs a light to work at night -- since this cannot shine through, and it had better not glare in the driver's eyes, it's a little more complicated to add it, but others have cited some off-the-shelf modules you can use. And you will need a contrast adjustment with a very wide range, to handle everything from full sunlight to dim night-time lighting.

To go in a car, it also must handle a wide range of temperatures. Check the freezing and boiling or breakdown points of the liquid crystal material. The LCD displays in gas pumps do handle a pretty wide range, although they need a temperature sensor to adjust the bias in cold weather.

Glare Reduction

[bongpig]

What about a standard Anti Glare screen for a monitor, worth about $5.00AUD in any computer store, newsagent, supermarket, kmart, blah blah blah...........

Not as easy as it sounds

[CompaniaHill]

Lockheed Martin evaluated a number of LCD displays for use by the FAA in airport control towers. Mission-critical, with contrast and legibility requirements from the darkest night to the brightest sunlight.

There are plenty of display vendors, but very few companies that actually manufacture the glass. So differences from one vendor's displays to another's are almost entirely in the way the glass is packaged. You'll need three things: an anti-glare coating (pick your favorite one) front-bonded to the LCD glass, a backlighting unit capable of putting out some serious lumens, and a cooling system that can keep the whole thing from melting. Simple, right?

The few displays that met the FAA's requirements were custom designs, built like tanks. I doubt you'd want one in your car. But anything less, and you'll be hard-pressed to meet your requirements. You've got a tough battle ahead. Good luck.

Security screens

[Webmoth]

Similar to anti-glare screens, you may be able to use a security screen which completely blocks off-axis viewing (I assume it would also block off-axis light sources).

I have seen (or rather "not seen") these used at Passport Control when entering the U.S. at the Miami International Airport. To the traveler passing through Passport Control, the computer screen appears totally black. To the Passport Control Agent, (I assume) the screen is perfectly readable.

I also seem to recall having seen these advertised in a Linux Journal at one time, but I don't recall the manufacturer.