Actually the best is negative mode LCD's. Like a cheap watch has.
They get their light from ambient light and reflect it through the LCD
from behind the LCD panel. The brighter the source
the easier they are to read. The problem is seeing them in the dark.
The best way to solve that is to flood light them, again like a cheap
watch, with an LED or incandescent source. European cars use these but
American cars don't because they basically come in one color Black
Letters on Grey background. And when the designers try to match the
panel lighting to the displays it doesn't "look harmonious".

The LCDs that washout are positive mode LCDs. They have to be backlit
but can be various colors. Thats why they are used in some cars. They
are only as visible as the light source behind them is bright. The sun
will always be brighter.

VFDs are brighter but the sun is brighter so they lose the washout war
also.

The Serial LCD module at
http://www.elproducts.com/serlcd.html
is the negative mode that is very visible in bright sunlight but
doesn't meet all the requirements Julian was looking for.


--- Gabriel Gonzalez <tgo@CHIH1.TELMEX.NET.MX> wrote:
> LEDs will washout in direct sunlight or any other strong light
> source, if
> you want to use leds you'll need some kind of hood.
>
> For car usage it is better to use VFDs, and even these are not
> perfect.
>
> Gabriel
>
>
> -----Original Message-----
> From: Julian Fine <julian@FINE.CO.ZA>
> To: PICLIST@MITVMA.MIT.EDU <PICLIST@MITVMA.MIT.EDU>
> Date: Wednesday, May 19, 1999 12:57 PM
> Subject: Re: [OT] LED Display
>
>
> >Hi,
> >Has anyone seen a display with the following specs
> >1. Red LED
> >2. Character size 10mm
> >3.16 characters per line
> >4.6 to 10 lines
> >5. full asci
> >6.drivers on board
> >7. Prefer rs232 driver.
> >
> >Basically something to display text in a vehicle that is easy to
> read in
> all
> >light conditions and will not dissapear if the car stands in the
> direct
> >sunlight like some LCD displays do.
> >Thanks
> >************* Julian Fine ***********
> >********** julian@fine.co.za ********
> >******* http://www.fine.co.za *******
> >** http://www.eagle-wireless.co.za **
>


===
Chuck Hellebuyck
Electronic Products
chuck@elproducts.com
*****Program PICs in BASIC Special!*********
Complete 16F84 package for only $115.95
Includes: Compiler, EPIC Programmer, 16F84 PIC, Cable & Batteries
http://www.elproducts.com
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