Waterproof camera: foggy image and heat dissipation problem solved

The infrared waterproof camera is a CCTV surveillance camera device that integrates the camera, rain cover, infrared LED light and other components . The basic principle of its night vision is to use an ordinary camera equipped with a photocoupler CCD to sense the spectral characteristics of the infrared light source (that is, it can sense visible light and infrared light), and use the additional LED infrared light as the "illumination source" to form an image at night or in a dim light environment.

Solution to the fog and water vapor problem of waterproof cameras

Problems such as fog and water vapor can be solved in the following ways.

In the first case, fog appears inside the machine:

The formation of fog and frost is due to the condensation of saturated water vapor in the air when it encounters cold. Due to the strength and weakness of the cold environment, it condenses into frost and fog respectively. Infrared camera During the working process, especially indoor cameras, fog or frost often forms on the protective cover window glass due to fog or water vapor, which makes the camera unable to see the object clearly, directly affecting the monitoring effect.

Different companies have different solutions to this problem. They add defrosting circuits, open vents, fill with nitrogen, add fans, add desiccant, etc. Different methods will produce different results. Some can solve the problem, while others cannot. However, from the most basic perspective, it is necessary to strictly control the cleaning of materials and try to eliminate the presence of volatile substances. For example, there should be no residual flux on the PCB board, and the light-shielding rubber sleeve should be made of high-quality silicone material.

In the second case, frost and fog appear on the outside of the machine:

When the camera works in an environment with high humidity, dirt easily appears on the window glass of the protective cover, which blocks the camera's view.

Solutions: 1. Add wipers to the protective cover and clean the glass by controlling the wipers. 2. Use invisible wiper window glass. Compared with ordinary window glass, invisible wiper window glass has the function of repelling water and dust.

Finally, some requirements for housing sealing in high humidity conditions

If the infrared waterproof camera is used in the north, there will be a large temperature difference between the inside and outside of the body, and the front lens will become fogged. Therefore, the machine must have good sealing properties and the protective cover must also have good rainproof properties.

At present, there are certain technical problems in the sealing of mainland China's technology , such as the design of the shell, where joints and screw interfaces are often leaking.

How to make the sealing better? The basic solution is this:

1. Add waterproof rubber sleeve and water pad at the interface to play a waterproof role, the effect is ideal.

2. Apply waterproof glue to the connection screw holes to enhance waterproofness.

3. The infrared waterproof camera uses an aluminum alloy shell to improve the accuracy of the interface, and is bonded with high-quality silicone material, the effect is also relatively ideal.

Waterproof camera image problem solution

Why does the infrared waterproof camera flicker? As mentioned before, when the lighting intensity is lower than the threshold, the infrared light turns on. When it is higher than the threshold, it turns off. Let's consider the situation when the lighting intensity is slightly lower than the threshold: the photosensitive element detects that the lighting intensity is slightly lower than the threshold, and controls the infrared light to turn on. After the infrared light is on, the detected illumination increases (plus the infrared light that returns in reverse), and exceeds the threshold, the infrared light is controlled to turn off, resulting in a decrease in the detected illumination, and the infrared light is controlled to turn on again. This goes back and forth, causing the image to flicker. This situation occurs because of the principle. It is not normal, but at least it is not a product quality problem.

First, it prolongs the use time of the infrared light of the infrared waterproof camera, affecting the service life of the product;

Second, turning on the infrared light when a color image can still be produced will cause the image quality to deteriorate;

Third, infrared eyes are generated on color images (infrared eyes are also determined by principles, and people do not want to see the phenomenon). If the threshold is low, it is possible that the infrared light cannot be turned on in time when supplementary lighting is needed.

Common infrared waterproof cameras nowadays generally use photosensitive elements to detect the lighting intensity of the environment. According to the threshold value determined in the design parameters, a control signal is generated to turn on the infrared light. The threshold value varies depending on the environment in which it is used, the preferences of the user, and the importance of various factors considered by the designer. The products of different manufacturers are different. For example, 20, 10, 5Lux., etc. A high threshold value will turn on earlier. It is possible that the infrared light will turn on before the camera has converted from color to black and white. This will have three disadvantages.

So how to solve this problem?

The problem occurs when the ambient illumination detected by the photosensitive element is slightly lower than the threshold. There are two situations:

1. This problem occurs at a certain point in the evening for a short period of time. If we do not want to increase the cost and use a general chip, our idea is to explain the reason to the user and tolerate it.

Second, if this problem occurs when the lighting intensity is stable, it must be solved.

1. Change the threshold.

The thresholds of the same model of product are different and there is dispersion. Replacing a product may solve the problem.

The manufacturer provides products with different design thresholds for replacement.

Using products with higher threshold design parameters will reduce the possibility of flickering.

2. Change the environment

Change the intensity and angle of lighting.

Slightly change the installation angle of the infrared waterproof camera, move it up and down or left and right, and the illumination detected by the detector will change a lot, leaving the threshold, thus solving the flicker problem.

3. Use high-quality low-light camera chips with backlight compensation and anti-glare function, especially dedicated IR lenses ;

In addition, when there are people or other objects near the infrared waterproof camera that reflect the infrared light, the detected illumination will change repeatedly, causing flicker. For example, when doing demonstration tests or testing , the camera is installed at a low position and there are objects blocking the camera at close range.

This is not a problem. When the infrared waterproof camera is in the normal installation position, this phenomenon will naturally disappear. For example, during the demonstration, just be careful not to let the infrared light directly back to the photosensitive element from a very close distance.

Solution to heat dissipation problem of waterproof camera

The infrared waterproof camera uses 58 lamps in series to make a light board. The heat generated by its lamp is transmitted through the positive and negative poles, and it does not play a role in heat dissipation. After working for a period of time, a fracture layer will appear, resulting in the phenomenon of light decay.

When it comes to surveillance infrared waterproof cameras in the market, everyone knows them. I believe everyone has a clear understanding of its advantages and disadvantages. Let’s take the heat dissipation effect as an example.

The traditional infrared waterproof camera uses 58 lamps in series to make a light board. The heat generated by its lamp is transmitted through the positive and negative poles and does not play a role in heat dissipation. Its packaging material is epoxy resin. After working for a period of time, a fracture layer will appear, resulting in light decay. After 3 months, the traditional infrared waterproof camera can decay by 30%.

In order to change the situation where the infrared waterproof camera has a short life due to poor heat dissipation, the new generation of infrared waterproof cameras has made innovations and improvements in the lighting.

The new generation of infrared waterproof cameras uses a single lamp, one of which is equivalent to 70-80 infrared lamps in a traditional camera. The lamp is connected to the lamp through a lamp board (the lamp board is made of aluminum alloy) and there is also a heat sink, which is connected to the shell through the chip to achieve heat dissipation. Its packaging material is selenium glue. Because there is no fracture layer, there will be no light decay. The night vision effect is very good, and the service life can reach 5-10 years. No decay can be seen by the naked eye within 2 years.

Therefore, the new generation of infrared waterproof cameras have good heat dissipation. If you find that the shell feels hot after use, it means that its heat energy has dissipated, which is a good thing. Good heat dissipation also prolongs the life of the camera.

The new generation of infrared waterproof cameras is integrated with many dots. Each dot matrix lamp can integrate 60-80 LED light-emitting crystals. The volume after integration is only the size of a fingernail, and the finished product will not be too large. Because the dot matrix lamp is a highly integrated LED, its volume is much smaller than other products.

The main reason for the small size is that it is easy to use. If you use dozens of single LEDs to combine infrared light sources and install them on a high-speed ball machine, the effect is imaginable. The light emitting angle of ordinary products is generally 7°-10°, so a beam like a flashlight is formed. The angle of our light source can reach up to 180°. It can evenly illuminate the entire space indoors. The optical output of a single LED is 5mw-15mw, while the optical output of a dot matrix lamp reaches 800mw-1000mw, and the volume is only the size of a penny. This shows that the dot matrix lamp has clearer, brighter, and longer-distance monitoring images than similar products on the market.