How Does Night Vision Work?
As a well-known fact, the night vision is the capacity of detecting the infrared light which is invisible to the human eye which is further converted to a visible form with the help of the image enhancement process.
To make this possible, an image intensifier tube is required to be present in the night vision devices, as they help in amplifying the darker images by converting the photons into more electrons to enable vision in the darkness. To get a much clearer picture, look at the detailed description of the image enhancement process below.
What Are The Steps Involved In Image Enhancement?
The image enhancement works with the steps that are the following,
Light capture- Mostly, the night vision devices consist of a common lens known as the objective lens. With the help of this lens, the infrared light and the atmospheric light are captured.
Light transmission- The image captured is collected and sent to the image intensifier tube, where the light hits the light-sensitive surface.
Photon conversion- The light transmitted is made of photons of various colors which are converted to high energy electrons with the help of the photocathode that is present in the image intensifier tube.
Electron multiplication- The intensifier tube consists of a small glass disc called the microchannel plate, which is made of the fiber optic technology, where it performs the release of numerous electrons after amplification, by a process called the cascaded secondary emission.
Creating image- These electrons reaches the end of the tube, which has a screen that is coated with phosphors. The electrons maintain the similar alignment to that of the photons as they pass through the tube and provide a clear image and in turn result in the phosphors to excite and create an image that is green in color. This is why the night vision images are green in general.
Magnification- The phosphor coated, green colored image is then passed through the ocular lens which performs the magnification and focuses the image on being visible. The resulting image can be viewed by connecting the night vision device to a monitor or directly through the lens itself.
This is the mechanism with which the night vision devices work with. If you find this article to be useful, share it on social networking sites.