Anyone found a GOOD 128x64 sunlight readable display?

I have an application which will require a highly readable outdoor display. I am using an Optrex F-51553 but it isn't cutting it.

Has anyone seen a really good LCD / VFD / somethingelse display which works REALLY WELL outdoors?

Reply to
John Harlow
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Any Non-color LCD display should be readily sun light readable.

vax, 3900

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Reply to
vax3900

That's what the Optrex is, but it has a contrast ratio of only 6:1 and no spec on brightness.

BTW, what is "viewing angle... 6 o-clock" supposed to mean???

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formatting link

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Reply to
Rick Merrill

spec on brightness.

It sure would be nice if everyone just supplied things like brightness on their datasheets for all their products, whether good or bad. I hate marketing departments.

I wondered the same thing. Perhaps it means it can only be read at dusk ;)

Reply to
John Harlow

A standard B/W LCD has no brightness from itself. All the brightnes it has, comes either from a backlight of from the ambient light. And the more ambient light it gets, the higher the contrast.

Meindert

Reply to
Meindert Sprang

no

;)

It is the angle from which the LCD shows the highest contrast. 6 o'clock means that it is best viewed from lower than right in front of it. LCD's also have 12 o'clock directions. An LCD watch is typically 6 o'clock while a table-top device with an LCD on the front is typcally viewed from a higher standpoint and therefore has a 12 o'clock display. If you view an LCD from the opposite direction, you will hardly see the segments turn black anymore. The faint image that you see is the shadow of the segments on the back-reflector.

Meindert

Reply to
Meindert Sprang

Fair enough, but the Optrex has a builtin backlight ...

Reply to
Rick Merrill

Who invented THAT standard?! I have an embedded control panel for an operator who may be at different places in front of the machine yet still needs to see the screen. For TFT displays the maximum viewing angle I have seen is +- 60 degrees or 120° side to side.

Top to bottom viewing is less important because the operator's height doesn't change ;-)

Reply to
Rick Merrill

It means the display has an asymmetric viewing cone, and the view angle BELOW dead-on horizontal is bigger than the view angle ABOVE dead-on horizontal.

Reply to
Lewin A.R.W. Edwards

This is to do with VERTICAL viewing angle.

It is a fact of life to do with structuring the light to go through the polarisers of the TFT itself, it is NOT a standard as such but the limitation of TFT technology. However if you make the glass one way round the contrast ratio is better when viewed below a line at right angles to the middle of the screen, typical application Laptop screens, the other way round is used for monitor displays and what has generically in the LCD market been called industrial displays.

If you do not believe this happens look at your screen from above and below the display and see the differences.

Side to side viewing angle is easier to achieve, you will find the VERTICAL viewing angle, for operators of different heights, is a much smaller range.

All your operators are the same height?

Top to bottom viewing is IMPORTANT and causes colour changes. The amount of times I see people trying to do digital photo manipulation on 18bit displays and complain that the print out is wrong compared to the screen, when they are in fact viewing the screen at the wrong angle.

I have spent too many years looking at these artefacts and the corrections required on live video feeds, to know that in many applications it is important in quite a few applications. Flat colour GUI interfaces without images see the problem LESS due to the normally limited range of actual colours over the WHOLE screen.

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Reply to
Paul Carpenter

It is easier (=cheaper) to make LCDs that have a "preferred view orientation". Symmetric-angle LCDs are either:

  1. Narrow angle, or
  2. More expensive than asymmetric-angle LCDs.

LCDs with wide viewing angle are only justified in monitor and TV applications, and often not even then, for the low-cost monitor market at any rate.

+/-80 degrees all around is commonly available, at least in the larger sizes (17" and up). This is usually achieved with a special coating and often at the expense of brightness.

It is *very* important if you are either designing an appliance to work in portrait mode, or if your appliance can be either placed on a desk or mounted on a wall according to user preference (e.g. industrial monitor).

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Reply to
Lewin Edwards

has,

Yes. But this backlight does hardly contribute to the illumination of the display when outside. This backlight is only necessary to view the display in the dark. Try to read something about reflective, transflective and transmissive LCD's and it'll become all clear.

Meindert

Reply to
Meindert Sprang

It is not an invented standard, it is just a physical fact of LCD displays.

Yes, and mine is even 170 degrees, both horizontal and vertical. But these are different displays. such a display depends on special filters and a very bright backlight, that's why you don't see anything on them when the backlight is off. It's an entirely different technology than the Optrex and other reflective displays.

Ah, and they're all selected on the same length at their job interview?

Meindert

Reply to
Meindert Sprang

An LCD designed to be read in direct sunlight should not *have* any brightness to be specced. You want a reflective display for such environment, not a backlighted one --- fighting the sun's incoming illumination with a (battery-powered) backlight is a battle you can't win in the long run, and it's not worth trying.

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Hans-Bernhard Broeker (broeker@physik.rwth-aachen.de)
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Reply to
Hans-Bernhard Broeker

...

Now that I think of it, this was the best answer!

Yeah, we know. But why is there no degrees :-) What happened to

4'oclock - happy hour?-)

Of course; that is all pretty obvious.

Twins!-)

Certainly, but why is there not a range of 12, 1,2,3,4,5,6 o'clock? - RM

Reply to
Rick Merrill

...

Thanks for the information.

Yes of course (c.f. smiley). In our case the operator can adjust the vertical angle once then moves from side to side. I suppose in other cases the operator might stand or sit making vertical viewing angle important. - RM

Reply to
Rick Merrill

........

LCD makers like to use quasi standards, and hide as much as possible (even in the data sheets) that may look bad. For example in various 'standards' over time VGA meant 640 x 480 x 16 colour, SVGA meant 640 x 480 x 256+ colours upwards, then came XGA and other definitions. LCD makers use

640 x 480 VGA 800 x 600 SVGA 1024 x 768 XGA 1280 x 1024 } 1600 x 1200 } UXGA

However their vertical viewing angles are often ranges like -10 to +30 degrees, or -30 to +10 so rather than give absolute figures they know the vertical viewing offset is a known attribute so they actually normally only quote the offset direction for simplicity to sales people. For a lot of applications like laptops that is sufficient as the angle of the display is easily adjustable to compensate. My experience of LCDs is more that those selling/making are more interested in hype and quasi standards than speccing the parts.

I have before now had to measure what the viewing angles are with sensors in a dark box to get actual angles!

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Reply to
Paul Carpenter

There's also the new laptop 1400x1050, and I've seen pseudo-"widescreen" at various resolutions - 1280x800 being one. Weren't SGI LCDs available in a rather blatantly widescreen 1600x900? ;)

1280x1024 is an odd one really, 5x4 rather than 4x3!

pete

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Reply to
Pete Fenelon

Well actually the problems of resolution, vertical viewing angle, and how bright (direct or reflected) is common to colour and black and white (mono or greyscale).

Actually I am amazed no one has mentioned the other daylight viewing problem that most people over look...

If viewing in bright sunlight (especially outdoors) beware of operators and polaroid sunglasses, (especially those using horizontal polarisation) as it is possible to see nothing on the display as polarisation can cancel all the display! Go back and check polarisation of light physics. I have seen this effect on reflective LCDs on bench PSUs, when using sunglasses for a particular experiment.

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Reply to
Paul Carpenter

John Harlow:

What are your power requirements?

The times I've worked on something for a harsh/bright environment without power limitations, we used a VFD (mainly for the temperature specs, but the brightness was also very good). I've only used the character displays, but I see graphic ones advertised these days.

Hmm... IEE doesn't seem to have graphic VFD's, but Noritake does, didn't take the time to look further.

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Charles Allen
Reply to
Charles Allen

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