WORKING OF NIGHT VISION DEVICES

It is known that the process of vision is done by reflection of visible light rays of the body we are looking at our eyes, which in turn is an image of an object on the retina and the image information transmitted through the optical fiber to the brain to translate body image. Hence, the process of vision depends mainly on the visible light rays, whether of sun or electric light bulbs. For this reason, in the dark can not see things eye to the lack of visible light reflected from the body to the eye.
The question now is how to improve visibility in the dark? 

To answer this question should shed some light on the electromagnetic spectrum that surrounds us, and colors What we’re saying is a fraction of the electromagnetic spectrum
Each region on the spectrum of electromagnetic energy-depending on the wavelength: the shorter wavelength has higher energy. Consequently the color blue with a shorter wavelength in the visible spectrum has higher energy than red because it has a wavelength greater. The infrared spectrum by the color red and this means that the capacity is less. 

Infrared is divided into three regions, and visible radiation is divided into seven different colors (colors of the spectrum known) and the three areas of the infrared spectrum is: 

The area near the infrared Near-infrared, the closest possible to the visible spectrum and with a range from 0.7 microns to 1.3 microns. 

Central Mid-infrared Central Region Mid-infrared, a region of the electromagnetic spectrum in the range 1.3 microns to 3 microns. These rays are used in remote controls
X-ray thermal Thermal-infrared Thermal radiation Thermal-infrared, which occupies a greater range of the electromagnetic spectrum from 3 microns to 30 microns. That occupies the largest range of the electromagnetic spectrum from 3 microns to 30 microns. 

X-ray thermal Thermal-infrared Thermal radiation Thermal-infrared rays are emitted from objects as a result of temperature and is not reflected rays from the objects. Rays are emitted by objects due to temperature, not rays reflected from objects. 

And back x-ray thermal emission in the infrared spectrum of exciting the atoms forming the body at temperatures above absolute zero and return to the state of excitement and this is causing to the release of electromagnetic radiation in the infrared region. Since the atoms in the event that a continuous excitation to energy levels higher excited level, and then return to the energy level ground ground-state energy level. When electrons gain energy as a result of corn temperature move to orbits with higher energy and eventually and return to the level of primary energy Ground State absolute power gained in the form of electromagnetic spectrum in the infrared wavelength range from 3 microns to 30 microns according to the degree of excitement . 

For example, when heating a spoon to start a flame temperature of the spoon growing, and produces at each temperature emission of infrared (heat) until it reaches the temperature to a certain extent the spoon begins to flare and reddish, and here we have entered in the visual wavelengths because the temperature close to 500 degrees Celsius and maximum flare up when it becomes close to the outstanding color white (more than 1000 degrees Celsius).
Conclude that every object radiates electromagnetic spectrum at temperatures above absolute zero, and the more the temperature increased the degree of excitement and this leads to the emission of electromagnetic spectrum, which is in the infrared at low temperatures and the greater the temperature approached the emitted spectrum to the visible spectrum. 

Hence, based on the idea of night-vision infrared (heat) emitted from objects, and this is what we’ll explain it now ……. Hence, based on the idea of night-vision infrared (heat) emitted from objects, and this is what we’ll explain it now …….
How do night vision devices? How do night vision devices? 

By the lens system similar to the video camera lens work on a compilation infrared emitted by objects. By the lens system similar to the video camera lens work on a compilation infrared emitted by objects. 

Infrared collected fall on an array of sensors sensitive to infrared work on the thermal map of the body called thermogram.
The organs of Aktronip convert the image to the thermogram thermal electrical pulses. 

Unit signal processing signal-processing unit to translate the image taken from the thermal sensors to the information for display on the screen. 

Send a signal processing unit and signal-processing unit information to the screen in the form of colored areas reflect the temperature and all the information collected the image. There are two types of night vision devices, one operating at room temperature, known as the Un-cooled and can detect differences in temperature of up to 0.2 degrees Celsius, the most prevalent. The other type operates under temperatures below room temperature and to cool it, known as the Carnival Cryogenically cooled a price and can detect differences in temperature of up to 0.1 degrees Celsius, and for distances up to 300 meters.
Types of night vision devices 

Can be divided into night-vision gear into three sections: 

Telescope Scopes, machines that prove the weapons to hit the targets night or hand-held for the transition from night vision to normal vision.
Spyglass Goggles, which are often mounted on the head and used to roam through which during the night. Cameras it looks like a traditional video, but rely on imaging by infrared and in aircraft or control the buildings.
Uses night-vision gear: Uses night-vision gear: 

Night-vision gear for many applications such as applications in the areas of military and criminal research and Night Safari in the search for the missing things in the entertainment and protection systems and control. 

It should be noted that the first and most important applications of night-vision gear are the military uses to spy on the movements of the opponent and equipment during the night, as used by men in the control of their buildings of thieves and aggressors. criminal investigations in the study of movements of the thieves from the thermal effects left by their feet on the ground and the duration of abuse and follow-up the loot and other .