Infrared camera technology trends and market trends

With the security monitoring gradually becoming a hot spot for social demand, the development of security technology has been increasingly valued by all sectors of society. The scale of the domestic security market is also growing after the new century, and the functional requirements of users for security products have also changed. Previously, only visible light monitoring could no longer meet people's monitoring requirements. Nighttime lightless monitoring is an indispensable and important part of current monitoring systems. In the past, video surveillance system engineering was rarely applied to infrared lamps. Nowadays, the requirements for television monitoring system engineering are becoming more and more standard and higher, and natural sites are required to be continuously monitored for 24 hours in important places. The role of infrared in night surveillance is even more pronounced. It is used not only in important departments such as vaults, oil depots, armory, library of books, cultural relics, and prisons, but also in general surveillance systems, even in residential areas. The project also uses infrared cameras. This article mainly elaborates the development and application of infrared technology in video surveillance for readers' reference.

Infrared camera technology analysis

The method of realizing the camera night vision technology can use conventional visible light illumination, but this method not only cannot hide, but it also exposes the monitoring target, and the hidden night vision monitoring is currently using infrared camera technology. Infrared camera technology includes passive infrared camera technology and active infrared camera technology.

1. The passive infrared camera technology uses the principle of infrared light emission from any object at 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. However, the cost of the passive infrared imaging technology equipment is high, and the infrared image obtained is the image of the target surface temperature distribution, which is different from the visible light image that can be seen by the human eye, and cannot clearly identify the detailed features of the target, and cannot satisfy the “evidence” Requirements are mostly used in the military and are basically not used in civilian night vision systems.

2. The active infrared camera technology utilizes a special infrared light emitting diode (IR LED) to artificially generate infrared radiation, producing infrared light that cannot be seen by the human eye and captured by ordinary cameras, and radiating “illumination” scenes and environments. Using the camera's CCD image sensor, you can feel the spectral characteristics of infrared light (that is, you can experience visible light, you can also feel the infrared light), use ordinary low-light-rate CCD black-and-white camera or use the "daytime color night-time automatic black and white camera" or "infrared low illumination "Color camera" to reflect the infrared light reflected from the surrounding environment, so as to obtain a clearer black and white image screen, to achieve night vision surveillance. Therefore, most of the current infrared camera technology adopts active infrared camera technology and uses infrared light to match the use of the camera. Therefore, the infrared camera is a camera device that integrates a camera, a protective cover, an infrared lamp, and a power supply and heat dissipation unit.

Three types of infrared cameras

After infrared technology was discovered by British astronomer Herschel in 1800, more and more scientists used it in various researches. The application of active infrared camera technology in security monitoring has experienced rapid development in the past two decades. Technically mature, there are three ways to sum it up.

First, the halogen lamp: The halogen lamp's luminous power is very powerful. Of course, the power consumption and heat generation will be relatively large and the cost is relatively high. Its fatal disadvantage is its large size, insufficient heat dissipation, and very short life span. Within a thousand hours, and the red storm phenomenon is particularly serious, it is not suitable for civilian night vision surveillance.

Second, LED Infrared Lamps: The illuminant consists of a certain number of infrared light emitting diode arrays. Infrared Emitting Diode A PN junction is made of a material with high infrared radiation efficiency (common gallium arsenide GaAs). A forward bias voltage is applied to the PN junction to inject infrared light. The spectral power distribution is center wavelength of 830 to 950 nm, and the half-peak bandwidth About 40nm or so, it is a narrowband distribution, which is a range that can be sensed by a CCD camera. It is characterized by its small size, simple production process, easy quality assurance, low heat generation, and reasonable luminescent optical system. It can be completely free of red storms (using 940 to 950 nm wavelength infrared tubes) or only weak red storms (red storms are visible Red light), with a service life of more than 6000 hours, is an ideal device for making infrared light, and is widely used for night vision monitoring.

Third, LEDArray chips: In the late 1990s, LED Array technology with a luminous efficiency of 25% and a high degree of integration began to appear. With the mounting process and optical processing, the optical output of an LEDArray chip has reached 800mw-1000mw. LED replacement products, the advantages of this technology are:

1. The integrated body has a higher standard of military grade and is more reliable.

2, the integration of the body made of metal, good heat dissipation, easy to maintain low temperature during operation, unlike the traditional LED design, relying on two fine metal feet heat;

3, the use of special materials for the integrated body, so that life expectancy increases many times;

4. The luminous body is a single light source, so that the illumination beam is evenly irradiated on the target object, the luminous Angle can be varied, no flashlight effect;

5, highly integrated integrated design.

The emergence and popularization of LEDArray technology not only satisfies the “evidence” requirements of security video surveillance, but also effectively solves the problems of small lighting angle, poor heat dissipation, and large size, making it an ideal choice for high-quality night surveillance.

Infrared camera development obstacles

"Colorless distortion" and "night vision" exist at the same time is a big problem, it is due to the light conversion caused by the day and night, and flat light mirror and filter can not be automatically converted with the trouble caused. Under daylight, the camera can use a flat mirror to capture clear images, which can achieve the purpose of video surveillance. However, it cannot continue to work 24 hours a day, because in dark light, it cannot be monitored through flat lenses. Any object in a dark environment, and whenever night comes, it is obviously not practical to change the filter of the camera. Tongbao Lai used IRCut automatic conversion lens technology to solve this problem and LEDArray infrared night vision technology The use of the monitoring system ensures that the surveillance image at night is not distorted and has high definition, and can meet the needs of all-weather uninterrupted video surveillance.

Because the wavelengths of visible light and infrared light are different, the focus point is different, and the day and night screens cannot be clearly visible at the same time. Infrared lenses that have been developed with the coating technology in recent years also solve the focusing problem. Due to the problem of heat dissipation and small angle of the LED infrared lamp, serious infrared light attenuation, low luminous efficiency, and uneven brightness of the screen occur, and an infrared light source made of the LEDArray light emitting chip emits light due to its high brightness and small volume. The characteristics of variable angle, good heat dissipation, high integration and long life meet the night vision requirements of video surveillance for small size products and long different viewing distances.

The current infrared night vision market is quite confusing, mainly because the industry lacks a unified standard specification. For example, the irradiation distance of infrared lamps is often the highlight of various companies' propaganda, and they are not the same. The actual exposure distance is measured under what conditions. At that time, the ambient illumination is how the picture quality is presented. How can we not know it? This is the most serious consideration faced by infrared cameras. Solving this problem has become the focus of common concern among enterprises. Therefore, domestic companies must continue to lead in the infrared market. We must work with relevant government departments to jointly provide industry standards. Develop well so that we can continue to go further in the market.

The development of infrared night vision market

As the monitoring industry continues to grow, the demand for infrared will rise. All manufacturers should be different in the function of the product to meet the actual needs of customers. Long-distance night vision technology is a trend of the night vision surveillance market. Whoever grasps this trend will grasp the commanding heights of the market.

Video surveillance develops outdoors, outdoor surveillance develops into night vision, and the development direction of night vision is based on infrared. This trend has become the development trend of the camera industry. With the development of optoelectronics, microelectronics, micro-computers and digital video technology, the security industry has evolved from traditional simple analog to highly integrated miniaturization, digitization, intelligence and networking. In 2007, the global video surveillance equipment market was about 5 billion U.S. dollars, and it is expected to rise to 8.6 billion U.S. dollars in 2010, with a compound annual growth rate of 11%.

The active infrared technology from the early efficiency of only 5%, to the current efficiency of 25-30% of the LEDArray technology, to meet the short-range infrared night vision technology breakthroughs in the distance, and the use of new laser night vision technology is achieved One of the long-range night vision monitoring methods, because the laser has high brightness, good coherence, good monochromaticity, good directionality, long service life, and the CCD's sensitivity to the wavelength is greater than that of the LED. More distant distances, and light intensity is much stronger than conventional light sources. In addition, the integration with another type of night vision technology--low-light technology is also one of the future development directions. In the period of continuous improvement of both low-light and infrared technologies, taking into account the complementarity between the two, no increase in existing Based on the technical difficulty, how to merge the low-light image with the infrared image to obtain a better observation effect, these two technologies have become the hot research of the development of the night-vision technology.

After more than two decades of rapid development, the security industry has received increasing attention from the country and society. Since 2000, infrared cameras have emerged as a new concept product on the Chinese market in a large scale, from scratch, from bulky to exquisite and compact, and the irradiation distance is also from near to far, and technological development has gradually become “integrated”. The market share has been rising year by year. With the reduction of technical thresholds for infrared cameras and the increase in the supply of core parts and raw materials, as well as the growing awareness of surveillance and security in the civilian market, infrared cameras have quickly occupied the market with lightning speed, and in recent years, domestic The launch of some large-scale projects has also played a role in the development of the infrared night vision market. Since monitoring is the basic measure of security, with the development of the industry, the development of security technology is increasingly valued by all sectors of society. Security monitoring has gradually become a hot spot for social needs. These external factors are driving infrared nights. The market continues to heat up.