night vision

[raptor2]

I am feeling myself very confuse on Night Vision Devices.
In fact, I think is very difficult to understand clearly the difference between DEP/PHOTONIS tubes and ITT or LITTON.
Well, I am talking on practicall and effective difference.
Any oppinion?
Thanks in advance!

[tf_echelon]

I am feeling myself ...
haha.

[Uncle Sam]

LINK (http://www.ittnv.com/itt/Active/MilTopMenu/HowNVWorks)

Video (http://www.ittnv.com/images/itt/howitworks/nightvision_video.htm?rs=0505165548)

Night vision takes the small amount of light that's in the surrounding area (such as moonlight or starlight), and converts the light energy (photons), into electrical energy (electrons).

In the image intensifier "tube," photons enter the photocathode which in turn releases electrons. These electrons pass through a thin disk (a microchannel plate) that's about the size of a quarter and contains over 6 million channels.

As the electrons pass through the channels, they strike the channel walls which, in turn, release more electrons. By the time the electrons exit the microchannel plate, they have been multiplied thousands of times.

The multiplied electrons then are accelerated onto a phosphor screen (like that in television.) When the electrons strike the screen, the phosphor "glows" in the same pattern as the light (photons) that originally entered the photocathode.

The user then sees the brightened, intensified image--similar to someone "watching" a TV screen.

Simple.