Temperature Range of LCD (or other display)

[MuffinMan]

I'm developing a product that will have a very small LCD (or other
comparable display)... We are planning to do a segmented display.
(Size 1.5"x1")

It's required that the LCD work over the temperature range of -40C -
85C... I have not seen any LCD's that go down to -40C.

I don't have enough power to use a heater. I have 21mW available for
my micro, some analog cicuitry, some comm's circuitry, and the LCD.
So the LCD has to operate on minimal power.

Is this possible...? What's the lowest temperature anyone has seen a
display rated to?

Thanks...

 

[Hal Murray]

I don't have enough power to use a heater. I have 21mW available for
my micro, some analog cicuitry, some comm's circuitry, and the LCD.
So the LCD has to operate on minimal power.

What sort of ambient light conditions will you be working with?

Will a LCD need a backlight to be visible?

--
These are my opinions, not necessarily my employer's. I hate spam.

 

[MuffinMan]

On Jun 21, 12:45 pm, hal-use...@ip-64-139-1-69.sjc.megapath.net (Hal
Murray) wrote:

I don't have enough power to use a heater. I have 21mW available for
my micro, some analog cicuitry, some comm's circuitry, and the LCD.
So the LCD has to operate on minimal power.

What sort of ambient light conditions will you be working with?

Will a LCD need a backlight to be visible?

--
These are my opinions, not necessarily my employer's. I hate spam.

No backlight

No reliable ambient light... could be mounted in a closed panel...

thanks....

 

On Jun 21, 9:03 am, MuffinMan <AaronKrei...@gmail.com> wrote:

It's required that the LCD work over the temperature range of -40C -
85C... I have not seen any LCD's that go down to -40C.

<http://www.pacificdisplay.com/lcd_temp_range.htm>

 

[Roger Hamlett]

"MuffinMan" <AaronKreider@gmail.com> wrote in message
news:1182430994.814693.27330@g4g2000hsf.googlegroups.com...

I'm developing a product that will have a very small LCD (or other
comparable display)... We are planning to do a segmented display.
(Size 1.5"x1")

It's required that the LCD work over the temperature range of -40C -
85C... I have not seen any LCD's that go down to -40C.

I don't have enough power to use a heater. I have 21mW available for
my micro, some analog cicuitry, some comm's circuitry, and the LCD.
So the LCD has to operate on minimal power.

Is this possible...? What's the lowest temperature anyone has seen a
display rated to?

Thanks...
The problem is your power consumption...

The lowest power LCD's, are the traditional passive designs.
Unfortunately, these are also amongst the worst for low temperature
performance. Basically the update slows as the liquid crystal nears
freezing. The lowest temperature rated LCD's I know, support -40C, but
required more power than your total available, being TFT designs,or FSTN
designes based on polysilicon. Other low temperature displays working down
to your requirements, use other tehnologies (LED, VFD etc.), which all
need more power...

Best Wishes

 

On Jun 21, 3:51 pm, "Roger Hamlett"

The lowest power LCD's, are the traditional passive designs.
Unfortunately, these are also amongst the worst for low temperature
performance. Basically the update slows as the liquid crystal nears

TN *does* go down to -40 though. The OP didn't spec a response time...

 

[Don McKenzie]

MuffinMan wrote:

I'm developing a product that will have a very small LCD (or other
comparable display)... We are planning to do a segmented display.
(Size 1.5"x1")

It's required that the LCD work over the temperature range of -40C -
85C... I have not seen any LCD's that go down to -40C.

I don't have enough power to use a heater. I have 21mW available for
my micro, some analog cicuitry, some comm's circuitry, and the LCD.
So the LCD has to operate on minimal power.

Is this possible...? What's the lowest temperature anyone has seen a
display rated to?

Thanks...

Have you thought about an OLED?
Power consumption compared to TFT&STN?
It depends on how the panel is used. Under the condition that the
backlight is fully turned on, STN & TFT will consume around 200 mW, and
OLED is 20~50 mW, so the latter is much more power-saving.

However temp specs are much the same as LCD's, around -20 celcius to +70
celcius.

Perhaps this will give you the power you need for a heater, if the specs
are so tight.

have a look at:
http://www.dontronics-shop.com/product.php?productid=16574&cat=371&page=1

Don...


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Serial OLED uses standard micro-SD memory cards.
http://www.dontronics-shop.com/product.php?productid=16659

USB Flash Drive interface for existing products.
http://www.dontronics-shop.com/product.php?productid=16654

 

[Andrew Tweddle]

MuffinMan wrote:

I'm developing a product that will have a very small LCD (or other
comparable display)... We are planning to do a segmented display.
(Size 1.5"x1")

It's required that the LCD work over the temperature range of -40C -
85C... I have not seen any LCD's that go down to -40C.

I don't have enough power to use a heater. I have 21mW available for
my micro, some analog cicuitry, some comm's circuitry, and the LCD.
So the LCD has to operate on minimal power.

Is this possible...? What's the lowest temperature anyone has seen a
display rated to?

Thanks...

I would be surprised if you found an LCD that would cope with 85C, the

physics of liquid crystals having such a large temp range would be very
OT. Having said that having a heater on the back side of the inside
glass using a TiO2 film should be do-able. I have a little book called
"Liquid Crystals: Natures Delicate phase of matter" by Peter J.
Collings Princeton University press 1990 that will get you better
informed. However all this stuff has moved along a lot in the last 17
years. Try contacting some manufacturers.

regards Andrew