Night vision in security camera:

CONTENTS:

• Introduction
• Types of Night Vision
• Working of Technical Night Vision
• Night Vision Devices
• Generations
• Applications
• Conclusion
• Reference

INTRODUCTION:

• Night vision technology, literally allows one to see in the dark.
• It is originally developed for military use .
• Humans have poor night vision compared to many other animals.
• With the proper night-vision equipment, we can see a person standing over 200 yards (183 m) away on a moonless, cloudy night.

TYPES OF NIGHT VISION:

      It is  broadly classified into two types

• Biological Night Vision
• Molecules in the rods of the eye undergo a change in shape as light.
• Molecules in the human rods is insensitive to the light.
• Technical Night Vision
• Image intensifier
• Thermal imaging

  WORKING OF TECHNICAL NIGHT VISION:

    Technical Night vision can work in two very different ways

• Image Intensifier
• Night vision amplifies light to achieve better vision .
• A conventional lens, captures ambient light.
• The gathered light is sent to the image-intensifier tube.
• The light energy released electron from the cathode and
• These electrons enter micro channel plate and bounce off and generate more electron.
• Thousands of other electrons to be released in each channel.
• Original electrons collide with the channel,exciting atoms and causing other electrons.
• New electrons collide with other atoms, creating a chain.
• In image-intensifier tube, the electrons hit a screen.
• The energy of the electrons release photons and create green image on the screen.
• The green phosphor image is viewed through another lens.

Thermal Imaging:

All objects emit infrared energy as a function of their temperature.

• A lens focuses the infrared light.
• The focused light is scanned and create temperature pattern.
• The pattern created is translated into electric impulses.
• The impulses are sent to a circuit board that translates the information into data for the display.
• The signal-processing unit sends the information to the is play, and appears as various colors.
• Thermal images are black and white in nature.

Night vision devices are basically divided into three categories

    SCOPES

• They are monocular normal handheld or mounted on a weapon

   GOGGLES

• They are binocular and worn on the head.

   CAMERAS

• Used for transmission or recording of images mostly if the location is fixed

GENERATIONS:

Generation 0

     The earliest (1950’s) night vision products were based on image conversion, rather than intensification

Generation 1

•  Vacuum Tube Technology
• Full Moon Operation
• Amplification: 1,000
• Operating Life: 2,000 Hours

Generation 2

• First Micro channel Plate Application
• One-Quarter Moon Operation
• Amplification: 20,000
• Operating Life: 2,500 Hours

Generation3

• Improved Micro channel Plate & Photocathode
• Starlight Operation
• Amplification: 40,000
• Operating Life: 10,000 Hour

APPLICATIONS:

• Military
• Hunting
• Wildlife observation
• Security
• Hidden-object detection

ADVANTAGES:

• No particular skill required
• Accidents cases reduction
• Compact system
• 3x range visual

DISADVANTAGES:

• The only disadvantage is that the Initial cost too high.