Analysis of the current development status and constraints of domestic LED infrared cameras

As the name implies, an infrared camera emits infrared light that is invisible to the naked eye at night to illuminate the object being photographed, and then receives the infrared light reflected by it to form an image. When used at night, the infrared filter should be turned off so that it no longer blocks infrared light from entering the CCD. At this time, what we see is an image formed by the reflection of infrared light, not an image formed by the reflection of visible light. At this time, images that are invisible to the naked eye in a dark environment can be captured. Video surveillance is developing towards outdoor, and outdoor surveillance is developing towards night vision. The development direction of night vision is currently based on infrared light. This trend has become the view of most people in the camera industry.

Since infrared cameras can obtain clearer images in zero illumination environment at night and have greater concealment, they have been widely recognized by the market and their market share is gradually expanding. According to surveys , the domestic market demand for infrared cameras is large, and the market share of infrared camera products is rising year by year, reaching about 30% in 2010. From the perspective of the global security market, infrared cameras have very "Chinese characteristics". Even foreign brands such as Sony and Samsung, which have just entered the Chinese market, have begun to develop infrared cameras to adapt to China's localization. Infrared cameras are currently developing rapidly in the domestic market, but at the same time, the shortcomings exposed by infrared cameras in applications are becoming more and more obvious.

The development of infrared cameras

In order to meet the needs of all-weather monitoring, China's monitoring manufacturers began to explore infrared camera technology as early as 2001-2003. From the early camera plus infrared light board module to the integrated design of camera and infrared light, from the manual control mode of LED infrared light to the automatic control of photoresistor, and then to the introduction and application of camera dual filters; from the most basic video monitoring requirements to the emergence of infrared cameras with various functional requirements such as waterproof and riot control, strong light suppression, face recognition, and privacy shielding, all of which have witnessed the rapid development of China's infrared camera technology and market. After 2006, with more and more manufacturers pouring into this field, the infrared camera market has gradually formed a situation of oversupply, and the competition among manufacturers has become increasingly fierce. In the era of fierce competition in the security industry, infrared camera products, like other security products, have the same mark of the times. Objectively speaking, the prevalence of manual workshops and the lack of industry standards have restricted the development of the infrared camera market to some extent.

After the infrared technology was discovered by British astronomer Herschel in 1800, more and more scientists have been studying how to apply it in various occasions. Among them, the application of active infrared camera technology in security monitoring has been rapidly developed for nearly 20 years and is relatively mature. While infrared cameras are growing rapidly, product types are also constantly diversifying and application areas are further expanding. In summary, there are the following types:

First, the halogen infrared camera that has been eliminated: The halogen lamp has a very strong light power , and of course the power consumption and heat generation are relatively large, and the cost is relatively high. Its fatal disadvantage is that it is large in size, insufficient heat dissipation, and very short lifespan, generally less than one thousand hours, and the red storm phenomenon is particularly serious, so it is not suitable for civilian night vision monitoring. Halogen infrared cameras have a high power and a filter for light-heat conversion, so the heating problem is particularly serious, the maintenance cost is high, and the lifespan is short.

Second, LED infrared camera: LED infrared lamp is composed of a certain number of infrared light-emitting diodes. The infrared emitting diode is made of a PN junction made of a material with high infrared radiation efficiency (commonly gallium arsenide GaAs). A forward bias voltage is applied to the PN junction to inject current to excite infrared light. The spectrum power distribution is a central wavelength of 830~950nm, and the half-peak bandwidth is about 40nm. It is a narrowband distribution, which is the range that CCD cameras can sense. LED infrared cameras are generally suitable for medium and short distances of 10~100 meters, with the highest market share, but there is a problem of uneven illumination. It is mainly suitable for medium and short distance monitoring in corridors, halls, warehouses and other indoor areas, as well as the perimeter of buildings, community perimeters, roads, etc.

Third, LED array infrared camera: The core of the array infrared lamp is the light-emitting diode array (LED Array), which has the following advantages compared with the traditional LED: 1. High brightness . The output of a single LED Array is about 1W~30W, which is about dozens of times the output of a conventional single LED of 5~15mW, so the shooting distance is far; 2. High electro-optical conversion efficiency. The electro-optical conversion efficiency of ordinary infrared LEDs is only about 10%, while the electro-optical conversion efficiency of LED Array is increased to about 25%; 3. Small size. LED Array technology highly integrates the light-emitting unit, which is much smaller than ordinary LED infrared lamp products under the same brightness index; 4. Long life. The life of LED Array is 50,000h, which is much higher than that of ordinary LEDs. Array infrared lamp products have an obvious shortcoming, namely "eccentricity phenomenon". Since its ... ​ ​ ​ ​ ​ ​

Fourth, the dot matrix infrared camera uses a dot matrix infrared light source. The third generation of infrared light-emitting components used in the dot matrix infrared lamp is developed on the basis of the second generation product - array infrared lamp (LED--Array), so it is also called the second generation LED-Array. Compared with the first generation, the biggest advantage of the second generation LED-Array is its small size, good heat dissipation, slow attenuation, and long life, with a rated life of 50,000 hours. The dot matrix infrared lamp is also called high-power array infrared. The biggest difference from the low-power array infrared is that it has higher brightness and lower cost. Through independent lenses, the distribution angle of light can be adjusted arbitrarily according to the use requirements, thus solving the "flashlight effect" problem of the first generation and the "eccentricity phenomenon" of the second generation at the same time.

Fifth, laser infrared camera: The maximum irradiation distance of laser infrared camera can generally reach 300~5000 meters. Due to the concentrated energy and small angle, it is not suitable for close distance, and the current cost is still relatively high. It is more suitable for monitoring places such as forest fire prevention, oil fields, railways, water conservancy, scenic spots, military, breeding, ports and safe markets. With the further reduction of costs, it has been applied to many fields that require night vision monitoring, including communities. Therefore, the infrared camera needs to determine the camera type according to the specific use environment, especially the night environment.

Disadvantages of infrared cameras

Infrared cameras have been favored by users due to their outstanding advantages such as night vision, strong concealment, and affordable prices. However, the disadvantages revealed in the application process are becoming more and more prominent. The disadvantages that affect and restrict infrared cameras mainly include the following aspects:

1. Poor waterproof and heat dissipation effects

After long-term use, the infrared camera will have more or less soda inside (this phenomenon is mainly concentrated in the northern region). The main reasons for this phenomenon are that the sealing effect of the shell is not enough and the temperature difference is not taken into account when the camera is installed. When the infrared light starts to work, it will generate a lot of heat. At the same time, the heat dissipation effect of the shell is not enough, which will greatly reduce the service life of the camera.

2. The night vision effect is not ideal

This phenomenon is mainly manifested in the lack of flashlight effect or distance, which is mainly caused by the angle and function of the infrared lamp. The infrared lamp used in the current infrared camera is also called 850 infrared emitting tube, with a peak wavelength of 850 and an angle of 5-60 degrees. The smaller the angle of the infrared emitting tube, the farther the irradiation distance, and the more obvious the flashlight effect. On the contrary, the larger the angle, the less flashlight effect there is, but the distance is greatly reduced.

3. Color distortion

The color of infrared cameras will be more or less cast during the day. The most direct reason for this is the problem of the camera filter. Generally, infrared cameras use a double-peak filter that can transmit a certain proportion of infrared light. The advantage is low cost, but because natural light contains more infrared components, when it enters the CCD, it will interfere with color restoration, such as green plants turning gray and white, etc. (especially obvious in sunny outdoor environments).

4. Repeated jumps of critical points

This is because some cameras, whether equipped with IRCUT dual filters or dual-peak filters, cannot work stably in certain complex light environments. At the same time, because most manufacturers use simple methods such as photoresistors to control the working state of IRCUT dual-peak filters, the repeated jumps of the critical points are not satisfactory. However, if an intelligent chip is used for control, its fuzzy logic capability can effectively control the working state of the IPCUT dual filter.

5. Short service life

Short service life is a common problem of ordinary infrared cameras. It is inevitable that part of the electrical energy consumed by LED is converted into effective light energy and part is converted into heat energy. The problem is to reasonably control and dispose of the generated heat energy. When too much heat energy is generated or no appropriate cooling measures are taken, the temperature rise inside the machine is too high, resulting in too fast aging of LED and too fast decrease in irradiation distance. In particular, some manufacturers do not have a healthy business philosophy, one-sidedly pursue performance at the time of delivery, ignore the service life of the product, and desperately pursue brightness and distance without solving the problem of heating and excessive temperature rise, which is an important factor causing the rapid decline in its service life.

The many drawbacks exposed by infrared cameras have more or less restricted their own development. Some industry insiders believe that the popularity of infrared cameras this year is different from that of previous years. The security market has now entered an era of small profits. With the sharp rise in raw material prices, infrared camera manufacturers have to reduce costs while ensuring profits, which also leads to the lack of product quality assurance, and in turn, the product repair rate gradually increases.

Current market development status

Due to the domestic market demand for infrared cameras, the booming infrared cameras have also promoted the participation of many security companies. As the infrared camera market continues to mature, the infrared market has gradually formed a chaotic pattern of fragmentation and disputes. The fierce competition in the infrared camera market has not promoted the development of the entire market. On the contrary, some product problems that have been solved before often appear again. Then, there are several major factors that have caused the current shrinking situation of infrared cameras:

1. The market of handicraft workshops impacting regular manufacturers is quite chaotic

Since the threshold for the production of infrared cameras is low, and there are quite a few merchants in the market who specialize in the production and sale of camera accessories, this has opened up a fertile ground for the growth of handicraft workshops. Their ultimate goal is to pursue profit maximization. Obviously, quality has become an empty talk. Due to its low price, it has caused an impact on some regular manufacturers, causing the market share of regular manufacturers to gradually decrease. Under the pressure of competition, in order to keep the market, some regular manufacturers can only reduce costs. Under the pressure of manufacturers, various raw material suppliers can only gradually "shrink" the quality of materials, resulting in a decline in the overall quality of products. Quality problems that did not appear before or have been solved have begun to rise, and the market is in a fierce and vicious price competition. The security industry has only been developed for more than 30 years. At present, the market is in a period of "a hundred schools of thought", and there is no leading infrared camera company to guide the entire industry. In addition, many customers lack a correct understanding of infrared cameras, and the technical threshold of infrared cameras is too low, which also gives many small workshops an opportunity to take advantage.

2. The product system is single and the products are highly homogenized

Since 2006, there have been few new types of infrared cameras. Most manufacturers' products are still the products of 2006. If the products of different manufacturers are not labeled, it is difficult to tell the difference between the two products from the appearance alone. In fact, during this period, some companies have also updated their product lines, but it takes a long time for a new product to go from research and development to market launch. Due to the large price fluctuations in the infrared camera market, it is easy for a new product to suffer a price shock as soon as it is launched. In addition, most of the new products developed in the past few years have single functions and no special highlights, which makes it difficult to promote them.

3. Imperfect industry mechanism and lack of standards

The security industry has always been an industry with lagging standards. Since the security industry started in China in the early 1980s, domestic camera manufacturers still do not have an industry standard to restrict them. In such a chaotic and disorderly state, it is almost impossible to measure whether a camera is qualified. On the other hand, the national testing standard mechanism is not sound enough. The only authoritative institution for the quality inspection of infrared cameras in China is the Quality Supervision and Inspection Center of Security Alarm System Products of the Ministry of Public Security . The standard used by the center to inspect cameras is the "GB/T15865-1995 Camera (PAL/SECAM/NTSC) Measurement Method". The various tests are only for the clarity, voltage resistance, brightness, signal-to-noise ratio and other parameters of conventional cameras, and do not involve the testing of infrared cameras and their infrared lamp power, emission distance, night vision effect and other related indicators. However, this test cannot serve as a threshold and a strong constraint, which is also one of the aspects that lead to the chaos in the infrared camera market.

Development trend of infrared cameras

The birth of infrared cameras is in line with the special market demand in my country. According to the author's understanding, infrared cameras are basically not produced in foreign markets. The reason is that infrared cameras themselves are high-temperature products, which are potential danger factors in most monitoring environments, such as coal mine monitoring, industrial monitoring, etc. The second is that the low-price competition of infrared cameras has seriously affected the product life. According to surveys, the service life of ordinary infrared cameras is generally less than one year. The short service life of products may be more profit space for manufacturers, but it harms the interests of consumers for end users.

The infrared camera market is unstoppable, so manufacturers are constantly developing more cost-effective products. Foreign camera brands such as Samsung and Sony have also launched infrared cameras to adapt to China's localization, but in order to solve the shortcomings of infrared cameras, foreign countries have developed ultra-low illumination cameras. my country can also develop more advantageous infrared camera products to make up for its own functional defects and solve safety hazards.

At present, LED infrared cameras still have the highest market share in infrared cameras, but the illumination range of most products can only reach within 100 meters. In terms of application, infrared cameras are mainly used in the civilian field. After several years of development, the market of infrared cameras is constantly being updated. Recently, laser night vision cameras have appeared in the camera market, which can directly observe people and objects on the monitor at night without visible light, just like during the day.

Laser night vision camera technology is different from thermal infrared imaging technology and low-light night vision technology. Thermal infrared imaging technology can only see the thermal outline of people and objects, but cannot see the true face of objects. Low-light night vision technology requires a certain amount of moonlight, starlight and ambient light to see objects. If there is no light, nothing can be seen. Although infrared light auxiliary lighting can also see the target, it cannot overcome the infrared light burst, cannot be observed covertly, and is easy to expose the target. The image is interfered by light waves and cannot achieve the same visual effect and clarity as black light night vision cameras.

Since last year, a product called white light night vision camera has been launched in the camera market, which is a product corresponding to infrared camera. According to reports, the advantage of white light camera is that it can also present color images at night, which is different from infrared camera which can only take black and white images. White light night vision camera has dimming technology, and the intensity of light is determined by the surrounding environment. The darker the surrounding environment, the stronger the light. This white light camera is more suitable for remote factories with few people, and its conspicuous light can also play a deterrent role. However, the actual effect and product quality of white light camera still need to be tested by the market.

The development of infrared cameras still needs a long process. Infrared cameras have their advantages in some functions, but manufacturers cannot sacrifice the life of the product. How to solve the problems of short life and poor heat dissipation of infrared cameras is also a proposition that security companies need to solve in the future development of infrared cameras. It is hoped that my country's security products can bring more practical functions to users while ensuring product quality.