Do you know how night vision devices work in the dark?


As we all know, infrared night vision devices play a pivotal role in military warfare, so do you know how night vision devices can see the dark environment clearly?

The current night vision devices are mainly divided into active infrared night vision devices, thermal imaging infrared devices and low light level night vision devices. The active infrared night vision device uses photoelectric conversion technology to irradiate the emitted infrared light beam to the target, and then convert the infrared image reflected by the target into a visible light image. Although there is still faint light in the darkness at night, infrared night vision devices can transform the light that people can't see clearly and richly. They are often used in the army, customs, border defense, and night patrols.

Active infrared night vision device

The working principle of active infrared night vision

However, the infrared night vision device has a fatal shortcoming, that is, the emitted infrared light can be easily detected by the enemy's infrared detection device, so a thermal imaging infrared device is based on this.

Thermal imaging infrared camera

Thermal imaging infrared camera is also called thermal imaging camera. Its working principle is to convert the infrared radiation on the surface of the object into a visible image through the temperature difference between the heat emitted by the object and the background. Because the thermal imaging camera has the function of measuring temperature, it can Using the characteristics of object distribution on the surface of the object, the gray-scale image is pseudo-color coded.

The working principle of thermal imaging infrared instrument

Simply put, it is to convert the invisible infrared energy emitted by the object into a visible thermal image. Different colors represent different temperatures of the measured object, and the thermal imager is not affected by obstacles such as smoke and trees. It can work day and night. It is currently the most advanced night vision observation instrument for humans, but it is currently expensive. Only used in the military.

The imaging of the low-light night vision device mainly relies on a component called an image intensifier. When the weak natural light shines on the target surface, the image intensifier can enhance the weak target, and the enhancement ability can even be enlarged to hundreds of thousands of times. It is said that the low-light night vision device is a special telescope with its own intensifier. At this stage, it is the most widely used in the fields of military criminal investigation and night monitoring, but unfortunately the low-light night vision device can only be used at night and cannot be used normally during the day.

Low light night vision device

Knowing the working principles of the three commonly used night vision devices, do you know the difference between night vision devices and the surveillance cameras we usually use?

In fact, the infrared lamp is used to fill light during security monitoring work, and then the camera is used to capture the picture, which is mainly used to monitor the flow of people, and the monitoring effect is not particularly ideal in the night environment. The night vision device uses the infrared rays emitted by the object to image, instead of using the light source to fill the light image, and also uses a professional detection movement and thermal imaging lens, which is relatively expensive and is mainly used in the military field.