Large Blank LCD panel

[Riscyrich]

Guys

I want to make a large LCD panel and control module.

The idea is that I can fit this in front of a small window and alter
the amount of light coming through by altering the contrast of the LCD
(I think this is done by altering the refresh freq?).

Anyone have any ideas where I should start to look for information,
circuits, how to make the LCD panel etc.

Thanks for your help.

Regards,

Rich

 

[Spehro Pefhany]

Guys

I want to make a large LCD panel and control module.

The idea is that I can fit this in front of a small window and alter
the amount of light coming through by altering the contrast of the LCD
(I think this is done by altering the refresh freq?).

Anyone have any ideas where I should start to look for information,
circuits, how to make the LCD panel etc.

Why are you fixated on LCD as opposed to, say, electrochromic
technology?

LCD panels require a special liquid (which most LCD manufacturers
purchase), flat glass panels coated with transparent electrically
conductive electrodes (something like ITO (doped Indium Tin Oxide),
spacers (such as glass microspheres) and sealing material (perhaps low
temperature frit glass). It's not really high tech, but the materials
are special and it's not so easy to do in your garage/basement. A
window (as opposed to a display) doesn't need the etching of the
electrodes. Also required are optical polarizers. And cleanliness.

Maybe you can skip all the electronic stuff by just keeping one
polarizer fixed and mechanically rotating the other.

Best regards,
Spehro Pefhany

 

[Tim Shoppa]

Guys

I want to make a large LCD panel and control module.

The idea is that I can fit this in front of a small window and alter
the amount of light coming through by altering the contrast of the LCD
(I think this is done by altering the refresh freq?).

Anyone have any ideas where I should start to look for information,
circuits, how to make the LCD panel etc.

How large is "large"?

It's fairly straightforward to take a junked B/W notebook LCD display
and make a controllable window with that.

I don't know if the color screens that have become popular as of late
make it any more difficult.

LCD-based welding goggles visors (that electronically darken when
you're welding) are very common today. The 5-square-inch ones are
$100 or so, including the control electronics.

Tim.

 

[Lewin A.R.W. Edwards]

I want to make a large LCD panel and control module.

Kent Displays in Kent, Ohio (thank God I don't live an easy drive from
there any more) has this sort of application demonstrated in their lab
at Kent State. But you should be aware of two things:

1. Sunlight will degrade the LC material. This project has a definite
lifespan. Kent uses them for interior windows (between reception desk
and reception area).

2. You must apply alternating-polarity drive current to the LCD
electrodes. A few tens of hertz is sufficient. If you drive it with DC
you'll electrolyze the LC material and the panel will fade.