Finding a Display You Can Read in the Sun?

max3000 asks: "I'm currently building an embedded device that will be used outdoors, and the technology is pretty much nailed down at this point, except the display. Quite honestly, I'm confused and lost in all the display technologies out there: LCD (TFT, passive/active, and so forth), ChLCD, OLED, FED, AMLCD, EL, electrophoretic, ePaper like eInk, and more (some of which may overlap). Can you help a confused, fellow reader? What I need is (apparently) fairly complicated: an outdoor, sunlight-readable (at-a-glance readable, not squint-your-eyes readable), VGA/SVGA display. The display should have a 4-6 inch diagonal, capable of displaying at least 16 color grayscale, and it should be based on a technology with a roadmap to color in 2-3 years time. If not driveable directly from a PC, the display should come with a development kit that is." What small displays are out there that can meet these specifications?

Ask Sharp

[Ant P.]

They made the Game Boy Advance LCD.

Re:Have you looked?

[orclevegam]

I think that was his problem, he looked and got overwhelmed. There really is a large number of competing display technologies out right now, and without having display samples to look at I can understand his confusion. I'm not sure about the color option, or development kit, but if you're looking for something that dosn't need to be viewable in the dark e-Ink is very promising. Only major problem with e-Ink is the refresh rate is pathetic, so not really viable for any sort of video. Other than that, OLED is the hot new thing, but those are still hard to come by in larger display sizes, and even then pricey unless you're looking to buy in bulk and have some clout to throw around. Also coming over the horizon be looking for SED displays.

Re:Ask Sharp

[fbjon]

The GBA (SP) had a transflective TFT, and was perfectly readable in the brightest sunlight, but only when tilted towards the sun. Tilt it so the screen is in shadow, and you can't see anything, because the front-light is way too weak to compete with daytime ambient light. That's the real problem: either you turn your screen towards the sun all the time, or you put in a powerful enough light that can rival the ambient lighting, and speedily drain the batteries at the same time.

Gas stations

[Anonymous Coward]

"What small displays are out there that can meet these specifications?"

Simple. LCD with a backlight that turns off and on. Look at what gas station pumps use.

OLPC

[Anonymous Coward]

you might want to look at the OLPC http://laptop.org/ [laptop.org]

        * Liquid-crystal display: 7.5" Dual-mode TFT display
        * Viewing area: 152.4 mm × 114.3 mm
        * Resolution: 1200 (H) × 900 (V) resolution (200 DPI)
        * Mono display: High-resolution, reflective monochrome mode
        * Color display: Standard-resolution, quincunx-sampled, transmissive color mode
        * Special "DCON" chip, that enables deswizzling and anti-aliasing in color mode, while enabling the display to remain live with the processor suspended.

http://laptop.org/en/laptop/hardware/specs.shtml [laptop.org]

Re:Have you looked?

[djbckr]

Look into Aircraft Avionics Displays - contact some of those manufacturers (there are quite a few).

OLPC's XO

[Adhemar]

I googled in my memory.

At last FOSDEM, Jim Gettys gave a presentation [fosdem.org] of the technical specs of OLPC's [laptop.org] XO-1 machine. I remember I found the part about the low-voltage sunlight readable display [wikipedia.org] particularly impressive for a $135 device.

OLPC XO-1 manifacturer Quanta announced [slashdot.org] selling a XO-like device on the open market later this year, at a price around $200. Presumably it will have a display of the same technology.

Re:eInk

[Anonymous Coward]

Actually they Sony reader only does 2-bit grayscale, he wants 4-bit.

But otherwise, yeah it meets his requirements.

Solarism

[Xerotope]

We work outdoors a lot with our robots, and we found the best solution to be monitors made by Solarism [solarism.com]. They're kinda pricey, but they put out nearly four times the brightness of a standard LCD.

Re:eInk

[geekboy642]

There's a store nearby that has one of those on a demo stand. I wouldn't use that particular type of screen, the refresh rate is abysmal. Switching between pages has a noticeable and aggravating delay.

ePaper

[Meneth]

I recommend e-paper. The device I've tried, the iRex iLiad [irextechnologies.com], works in all well-lit environments. It even runs Linux.

Simple: Transreflective

[evilviper]

The only existing screen technology that likely suits your needs is transreflective LCDs. They're widely available, so you shouldn't have an problems.

Display tech with potential, like e-Ink, just isn't there yet, and likely won't be for several years.

Of course, if you want to go crazy, you could always grab an old LCD, and mount it in an enclosure with a massively powerful backlight, and lots of airflow directed at the screen to keep the LCD from burning up.