Is there such a thing as LCD window curtains? - Page 1
Forum section: electronics / general

author: Artlav
author_rank: Frequent Contributor
timestamp: September 18, 2015, 02:23:23 pm
content: Not the BTTF2 kind, no.I was thinking about a window-sized single pixel LCD display, essentially, glued on top of the window's glass.Unpowered it's transparent.With power it's opaque, with no sunlight getting through.Was something like that done before?I remember thinking about it a couple of decades ago, and writing it off as something ludicrously expensive the Bill Gates' "smart home" might have.But these days window-sized LCD screens are almost dirt cheap, and a single pixel thing like that should be even cheaper.So, why not?If no why, then where can i find one or how can i make one?That is, should i waste a good spare laptop screen experimenting, or can i just go shopping?

author: Balaur
author_rank: Unknown
timestamp: September 18, 2015, 03:32:26 pm
content: Yes, it's called switchable glass or switchable window tint. Or some proprietary name.

author: G7PSK
author_rank: Super Contributor
timestamp: September 18, 2015, 05:23:22 pm
content: I think it's used on the space station, certainly back in the early 90's when I purchased my first auto welding helmet the Racal sales man said it was. I do remember that back the the thing cost nearly a thousand pounds, £450 for the helmet and over £500 for the filter and blower unit on a belt that ensured the user did not breath welding fumes.

author: GreyWoolfe
author_rank: Unknown
timestamp: September 18, 2015, 07:22:59 pm
content: http://www.glass-apps.com/products/smart-glass-windows/?gclid=CjwKEAjw7O6vBRDpi7O-8OWSkwESJACNFsgxApqgvroOzWiVXYHkFTW27CGkCyqCx6r3jDZ4OHqb4RoC-abw_wcBThey also make a film that goes on the glass.

author: KermitDK
author_rank: Unknown
timestamp: September 18, 2015, 07:31:54 pm
content: Are you thinking of something like this ? :

author: Red Squirrel
author_rank: Super Contributor
timestamp: September 18, 2015, 11:26:35 pm
content: Saw something like that on one of Mike Holmes' shows, they used it for a shower glass, it was pretty neat.

author: AF6LJ
author_rank: Unknown
timestamp: September 18, 2015, 11:29:19 pm
content: As I understand it the sun solarizes the the LCD panels which makes them less able to provide a decent shade. I've seen this in amateur radio gear that use LCD displays they loose the ability to generate a high contrast ratio.

author: Psi
author_rank: Super Contributor
timestamp: September 19, 2015, 03:12:41 am
content: Yep, you can get it installed in your house, it just cost so much you wouldn't want toI've seen it being installed in a house on one of those home building TV shows

author: Chris C
author_rank: Frequent Contributor
timestamp: September 19, 2015, 03:51:44 am
content: The high cost was no surprise. What surprised me was energy consumption, 12W per square meter on the one I looked up. I'd expected it to operate like a capacitor.

author: Psi
author_rank: Super Contributor
timestamp: September 19, 2015, 03:58:01 am
content: I'd like to build a large 28" stand like in the first video on this page, then have a data projector at the rear to replace my desktop computer monitor. It would look awesomehttp://www.glass-apps.com/products/smart-glass-windows/?gclid=CjwKEAjw7O6vBRDpi7O-8OWSkwESJACNFsgxApqgvroOzWiVXYHkFTW27CGkCyqCx6r3jDZ4OHqb4RoC-abw_wcB

author: SeanB
author_rank: Super Contributor
timestamp: September 19, 2015, 06:45:22 am
content: It is a LCD, so will be a big capacitor operating at around 32Hz, so yes it will draw a bit of power to charge it to alternate voltages. ITO coatings in contact with the cholesterol in a standard LCD display will corrode with applied DC, so they need AC drive ( and it has to be an exact 50% duty cycle for long display life, otherwise there is a DC component to the drive which will kill the display with time) and this does use power, both in losses in the film resistance and in the dielectric absorption of the cholesterol used.

author: Chris C
author_rank: Frequent Contributor
timestamp: September 19, 2015, 10:58:36 am
content: Quote from: SeanB on September 19, 2015, 06:45:22 amI never knew that, thanks. Now the power consumption makes sense.