1. Working Principle
Working Principle of Infrared Night Vision
The principle of infrared night vision is to collect and enhance existing light by focusing light on the image intensifier through the eyepiece. Inside the intensifier, a photocathode will be “activated” by light and convert photon energy into electrons. These electrons are accelerated by an electrostatic area inside the intensifier and hit the phosphor surface screen (like a green TV screen) to form an image visible to the human eye. In simple terms, the principle of night vision is to convert the light (weak light or infrared light) signal from the target that is invisible to the human eye into an electrical signal, then amplify the electrical signal, and convert the electrical signal into a light signal visible to the human eye.
Working principle of digital night vision device
Digital night vision device is also called digital night vision device, and its English name is Digital Night Vision. Most digital night vision devices process and convert the low-light light into digital electrical signals through highly sensitive CCD (CMOS) image sensors, and then transmit them to the micro LCD display inside the night vision device.
From the description of the working principle above, it can be seen that the core components of infrared night vision device and digital night vision device are different. The former uses image intensifier (image intensifier tube), while the latter uses CCD (CMOS) image sensor. This is the main difference between the two, and it is also the root cause of other differences.
2.Applicable environment
Infrared night vision devices can only be used in dim light or complete darkness (that is, at night). Due to the limitation of the imaging principle, they cannot be used normally during the day. If they are turned on, they need to cover the objective lens cover and watch through the light hole. However, it is meaningless to use infrared night vision devices at this time, and it is not as clear as watching with the naked eye.
Digital night vision devices are completely unrestricted by the ambient light. The use mode can be adjusted to daytime or nighttime mode. It is an all-weather photoelectric instrument that can be used both day and night. Color imaging during the day, black and white or green imaging at night.
3.Magnification
Since the magnification of the infrared night vision device is about 0.5, it is not easy to achieve a high magnification with the lens, and the magnification is generally fixed, such as 1x, 3x, 5x, etc.
The digital night vision device itself also has a fixed magnification, but it also has a digital magnification. For example, the magnification of the Oonica S60 itself is 6x, and the digital magnification is 36x, which means that the overall magnification range of this digital night vision device is 6-36x. In addition, the magnification of the imaging system of the digital night vision device is close to or greater than one, so generally speaking, with the same magnification lens, the magnification of the digital night vision device will be twice that of the infrared night vision device. For example, the lens of the infrared night vision device with a magnification of 5x is 10x when replaced with the digital night vision device, which is very critical.
4.Image resolution
Infrared night vision devices are divided into 1st generation +, 2nd generation +, quasi-3rd generation, 4th generation, etc. due to the different levels of image intensifier tubes. The resolution of night vision devices of different levels is different. For example, the resolution of the 2nd generation + night vision devices in China is mostly between 50-60 line pairs, and it is still a relatively high resolution. Even with infrared, the viewing distance is about 100-200 meters. The ordinary CCD resolution of digital night vision devices is also above 50 line pairs. For example, the third-generation digital night vision device uses a low-light high-definition CCD photoreceptor. The image brightness can be adjusted through the system to reach the level of the second generation + image intensifier tube of infrared night vision devices. The infrared sensing ability is good, and the effective observation distance can reach more than 500 meters in total darkness.
5. Functional characteristics
As a night vision tool used at night, the most basic and main function of infrared night vision devices is night observation, and there are few other functions.
Digital night vision devices, especially the new third generation digital night vision devices, can not only take high-definition photos and videos, but also transmit HDMI high-definition videos, record time, date and sound, GPS positioning, electronic compass level, WIFI connection to mobile phone APP, etc. It can be said that digital night vision devices are a new multifunctional night vision device. Due to the unique functional characteristics of digital night vision devices, their application scope and industry are more extensive than infrared night vision devices.
6.Standby time
Night vision devices are also electronic optical products that require batteries to work properly. Most infrared night vision devices use CR123A lithium batteries with stable performance, and the battery types are relatively simple, but the standby time is about 4 hours. The digital night vision device also uses CR123A lithium batteries, and can also use AA ordinary batteries. Of course, you can also use power banks, car power supplies, direct current, and flexible power supply methods, and the standby time is longer than infrared night vision devices.
7.Service life
Infrared night vision devices use image intensifier tubes as core components, which are fragile. In terms of service life, the first generation is about 1,000 hours, and the second generation is about 10,000 hours. The service life of digital night vision devices is relatively long, basically semi-permanent.
In summary, infrared night vision devices are not as good as digital night vision devices? In fact, it is not entirely true, because infrared night vision devices were developed earlier and have more levels. In terms of application, in addition to civilian use, high-end infrared night vision devices are also widely used in military and government departments. As a new product in the night vision field, the application of digital night vision goggles in various industries is not as high as that of infrared night vision goggles. However, with the wings of technology, I believe that digital night vision goggles will fly further!