1. Deprt. Of Electrical and Electronics Engineering
TYPES OF NIGHT VISION
NIGHT VISION DEVICES
3.  Night vision technology allows one to see in darkness.
 It is mainly developed for military surveillance.
 We can see a person standing over 180 m distance in a
moonless and cloudy night.
 It plays a key role in search and rescue operations.
4. Biological night vision:
 Molecules in the rods of the eye undergo a change in shape
according to the light.
 Molecules in the human rods is insensitive to the light
Technical night vision:
 Image intensifier
 Thermal Imaging
5. Image Intensifier:
6. Night vision amplifies light to a better vision.
A convention lens will capture completely envelops the surrounding
The gathered light is sent to the image intensifier-tube.
In each channel there release thousands of electrons.
Electrons collide with each other and produce more.
The new atoms again collide and creates a chain.
These electrons after hitting a screen will produce photons and crea
a green image.
This green phosphor image is viewed through lens
7.  In order to understand thermal imaging, it is important to
understand something about light.
8. Three Types of IR rays:
Closest to visible light, near – IR has wavelengths
that range from 0.7 to 1.3 microns.
Mid – IR has wavelengths ranging from 1.3 to 3 microns.
Thermal infrared the largest part of the infrared spectrum,
thermal – IR has wavelengths ranging from 3 microns to over 30
9. All objects emit infrared energy a function as a
function of their temperature
10. All objects emit infrared energy a function as a function of their
A lens will focuses the infrared light.
The focused light is scanned and create temperature pattern
The pattern is translated into electric impulses.
The impulses sent to an electrical circuit board that translates the
information into the data to display
The signal processing unit sends the information and it appears in
Generally thermal images are black and white in nature.
11. Night vision device can be split into three categories
They are monocular normally
handheld or mounted on a
The night vision binocular and
worn on the head
Used for transmission or
recording images mostly if the
location is fixed
12.  Generation 1:
In 1950’s devices based on vacuum tube technology are
13.  Generation 2:
The vacuum tubes are simplified to single
stage in 2nd generation.
14.  Generation 3:
 The third generation night vision devices advanced in using small
15.  Generation 4:
In present generation the researches are being made to bring it
into the micro electron chips.
18.  In present scenario night vision the applications of night vision
technology is very essential to combat terrorism which is the major
problem faced by the mankind.
 After a long journey from 1950’s we have much developed night
vision technology but it is limited in use.
 It will yield good results in future if we use it in every field for