IR waterproof camera

The visible light visible to the human eye is arranged from long to short wavelengths, followed by red, orange, yellow, green, cyan, blue, and violet. The red light has a wavelength range of 0.62 to 0.76 μm, and the violet light has a wavelength range of 0.38 to 0.46 μm. The light shorter than the wavelength of violet light is called ultraviolet light, and the light longer than the wavelength of red light is called infrared light, and human eyes cannot see infrared light. Because a digital video camera uses a CCD to sense all light (visible light, infrared light, ultraviolet light, etc.), this causes the shot image to be very different from the image that we see with only the visible light. In order to solve this problem, the digital camera is equipped with an infrared filter between the lens and the CCD, its role is to block the infrared light from entering the CCD, so that the CCD can only sense the visible light, so that the image captured by the digital camera and our naked eye The images seen are consistent.

Infrared night vision, that is, in the night vision state, the digital camera will emit infrared light that people can not see to illuminate the object being shot, turn off the infrared filter, no longer block infrared rays from entering the CCD, infrared reflected by the object Into the lens for imaging, what we see now is an image formed by reflection from infrared rays, rather than an image formed by the reflection of visible light, that is, images that cannot be seen by the naked eye in the dark can be captured at this time.

At present, most infrared cameras use LED infrared light emitting diodes as the main material of infrared cameras.

The principle and characteristics of infrared waterproof camera and its selection and use In the television monitoring system project, infrared light was rarely used in the past, but due to the current increase in social crime rates, the role of infrared in night surveillance is more prominent, not only the vault, depot, It is used by important departments such as armory, library of books, cultural relics, and prisons, and is also used in general surveillance systems. Even the residential area television monitoring project also uses infrared cameras. This shows that people's requirements for television monitoring system engineering become more and more standard and more and more. More and more important sites require 24-hour continuous monitoring.

The method of realizing night vision can use conventional visible light illumination, but this method not only cannot conceal, but also exposes the monitoring target even more. Covert night vision surveillance is currently using infrared camera technology. Infrared camera technology is divided into passive infrared camera technology and active infrared camera technology. PIR technology uses the principle of infrared emission from any object above absolute zero (-273°C). Since the human body and the heat emitting object emit strong infrared light, other non-heating objects emit weak red light. Therefore, special infrared cameras can be used for night monitoring. The passive infrared camera technology is not adopted in night vision systems due to high equipment cost and failure to reflect the surrounding environment. Active infrared camera technology uses specially designed "infrared lamps" to artificially generate infrared radiation, produce infrared light that cannot be seen by ordinary people and can be captured by ordinary cameras, radiate "illumination" scenes and environments, use ordinary low-light-rate CCD black-and-white cameras or use "daylight The color nighttime camera that automatically turns black and white, or the "infrared low-illumination color camera," feels infrared light reflected from the surrounding environment to achieve night vision.

Performance Analysis of Infrared Waterproof Cameras Infrared cameras have prominent advantages such as long-range night vision, strong concealment, and stable performance in surveillance cameras, thus occupying most of the market in CCTV night vision surveillance. How to identify the advantages and disadvantages of the infrared hemisphere camera market? A good performance IR dome camera must have the following capabilities:

1. Infrared lamp operating conditions In general, the infrared lamp radiation power is proportional to the forward operating current, but near the maximum rated current of the forward current, the temperature of the device rises due to the heat dissipation of the current, making the optical emission power. decline. Infrared diode current is too small, it will affect the radiated power to play, but the operating current is too large will affect its life, and even make the infrared diode burned.

When the voltage crosses the positive threshold voltage (about 0.8V or so), the current begins to flow, and it is a very steep curve, indicating that its operating current requirements are very sensitive. Therefore, it is required that the operating current is accurate and stable, otherwise it will affect the performance and reliability of the radiation power. The increase in radiated power with the ambient temperature (increased ambient temperature due to its own heat generation) will reduce its radiated power. Infrared lamps are particularly long-range infrared lamps. Heat consumption is a problem that should be considered when designing and selecting.

Therefore, the use of infrared lamps must have a good constant current power supply and a good heat dissipation design. Middle Road Communications' zoom MCD, MDD, MED, and MBB series cameras have installed high-power infrared lamps (up to 24) and are powered by a high-power constant-current power supply. The internal circulation heat dissipation design enables them to reach remote nights. According to the effect (up to 220 meters) and the long life of the infrared lamp.

2. Infrared light utilization and red storm problems What is a red storm? Redstorm is due to the fact that the emitted infrared light contains visible light components.

Infrared lamps can be completely red-free (using 940-950nm wavelength infrared tube) or only a weak red storm. Middle Road Communications adopts AUCSITER infrared technology to reduce the infrared lamp's own heat consumption and to adjust the angle of infrared light to ensure that the infrared lamp's effective utilization rate reaches 90%. In the selection of infrared lamps, infrared light with a relatively large wavelength (910 nm) was selected, and red storms were strictly reduced to achieve a reddish effect.

3. Fogging and Frosting of Infrared Cameras The formation of fog and frost is caused by the condensation of saturated steam in the air, and is condensed into frost and fog due to the strong and weak cold environment. In the work process of infrared cameras, especially outdoor cameras often cause fog or frost on the protective window glass due to seasonal changes, temperature difference between day and night, and rain and snow conditions. As a result, cameras cannot see objects and directly affect the monitoring results. Midway Communications adopted the advanced electronic defrosting circuit to effectively control the saturated water vapor concentration in the cavity and achieved automatic defogging and defrosting.

4. Infrared camera window glass cleaning Infrared dome camera works in rainy, snowy or dusty environments. The window glass of the shield is prone to dirt, which can block the camera's line of sight. The solution is usually to add a wiper to the hood, and to control the wiper to clean the glass; another option is to use an invisible wiper window glass. Compared with ordinary window glass, invisible wiper window glass has the function of repelling water, dust, and snow.

5. The constant temperature of the infrared camera As the infrared lamp is configured with a large amount of heat, after the infrared lamp is started, there will be heat concentration in the front part of the infrared dome camera during the entire working period (in 12 hours), that is, the front temperature in the cavity is High, if not uniformly cooled, will affect the normal operation of the camera and other components. Middle Road Communications Co., Ltd. has solved this problem by designing and using an automatic air-conditioning system with forced cooling and cooling.

Automatic cooling and air conditioning adopts Peltier effect principle, temperature measurement control circuit can be automatically adjusted, the temperature inside the protective cover is constant within the normal operating temperature range of the camera, the temperature inside the cover is set at +5°C below the heating, +40°C above cold. Experiments show that the infrared hemisphere camera can work normally in an outdoor natural environment of -40°C to +70°C (direct sunlight).

6. In addition to the constant temperature of the infrared camera, the other advantage of using the automatic air conditioning system is that the infrared camera can be made completely closed, without leaving any cooling holes to prevent the entry of dust, moisture, and corrosive gas, enabling it to To adapt to the harsh environment of dust, such as large coal mines can also be used normally.