Nikon 9350 Binoculars User Manual


 
1-7
1.5 Evolution of Image Intensifiers
The image intensifier tube has evolved substantially over the past
few decades. This evolution is described by different generations
(“Gen”) of technology as follows:
Gen 1 – These are the first so-called night-vision devices and were
introduced in the early 1960s and first fielded in Vietnam. These
devices utilized a multi-alkali S-25 photocathode having a spectral
response extending from visible to about 850nm. In order to have
sufficient sensitivity for use in night vision applications, three Gen
1 image intensifier tubes needed to be cascaded, each producing
some gain. The result, though highly sensitive, suffered from
significant edge distortion as well as poor life expectancy (less than
1000 hours).
Gen 2 – By the 1970s, the microchannel plate was introduced that
delivered high sensitivity imaging without the need to cascade three
stages. As a result, night vision pocketscopes and night vision
goggles emerged as viable products with improved operation life
(2000-4000 hours).
Gen 2+ – More recently, improved Gen 2 devices have been
developed (known as "SuperGen") that deliver improved sensitivity
and improved lifetime (10,000 hours).
Gen 3 – By the early 1990s, image intensifiers became available
with photocathodes made from gallium arsenide. This produced
significantly more sensitivity and an extended near-infrared spectral
responsivity range to 950nm.
Gen 3 Thin Film –Introduced in 2002, thin film image intensifiers
incorporate a new manufacturing technique, which have made it
possible to increase further the unit's sensitivity, improve signal-to-
noise and contrast performance and reduce blooming due to
viewing bright sources.
1.6 Benefits of AstroScope Night Vision
The AstroScope Night Vision System is a modular system
incorporating a “common module” approach in which the image
intensifier is integrated into an assembly consisting of a front lens
adapter and a back body adapter. The AstroScope System delivers
several important benefits over other night vision systems. These
include:
Optimized Performance: Because of the modular design and
the accessibility to the image intensifier, optical adapters and
interfaces can be designed so that each configuration delivers
optimized performance. This is due to the accessibility to the photo
cathode as well as the phosphor image output.
Seamless Integration into Daylight Imaging Systems: The
AstroScope’s component interfaces are both electrical (where
electrical contacts connect components) and mechanical. This
results in a seamless integration with daylight imaging systems. As