The night Vision Binoculars work like this:
If you have watched science channels like Nat Geo, you will have seen the videos and images of wild animals, pictured at night. How?
Well, now you might have predicted what this article is all about. It’s about Hunting For Binoculars. The following post will help you understand the working of night vision binoculars.
The Way Night Vision Binoculars Work:
Before beginning to learn about the working of binoculars it is vital to know something about light energy. Little wavelengths contain very higher energies. There are many radiations specific to wavelength of light. One among those radiations is thermal IR. Unlike other reflective radiations, thermal IR is an emitted energy. Thermal IR radiation takes place because of repeated excitation of electrons at atomic level. The thermal imaging technique uses this kind of thermal infrared emission for night vision binoculars. There are two methods used in the manufacture of night vision binoculars.
All objects produce some quantity of thermal IR radiation. This radiated energy is collected by a set of hi spec lenses which focus mainly on the thermal IR. The intense light from the lens is scanned by the IR detector part which makes a specific temperature pattern of the light, called a thermo gram. The time used to create a thermo gram is about one thirtieth of a second. The Thermo gram is then changed into electric pulses which are then fed into a signal processing unit (SPU). The SPU transfers the content to the display where the image is created. The quality of the picture created on the display in the night vision binoculars relies upon the intensity of the infrared radiation.
A normal objective optical lens is used to focus the IR, in this technique. The collected light is then sent to an image amplifier tube where the image is intensified to an extreme level. The output voltage dedicated for the image amplifier tube is nearly 5,000 volts. This container tube has a photocathode that can convert energy of photons into fast moving electrons. These electrons are moved through the tube where they magnify into more high energy electrons. There is a special micro channel plate in this container. A micro channel plate is a small glass disc placed inside the image intensifier tube, having millions of microscopic holes drilled into the container. The Micro channel plate is made of fiber optics that is designed to carry the electrons to several regions. So when the moving electrons hit the electrodes fitted inside the micro channel plate, they are energized to a very high acceleration speed by the voltage supply across the electrodes. When these electrons hit the phosphor screen, their energy creates a visible image in the night vision binoculars. The phosphor screen generates a green image of the original object when one sees it through the night vision binoculars.