With the rapid development and popularization of the Internet, the security monitoring industry has also stepped into the network era from the simulation era, and is developing in the direction of networking, high-definition, and intelligence. Because of this, the demand for front-end surveillance camera products has also changed, and high-definition network cameras have gradually developed and matured under the impetus of this demand. Judging from the current situation, although analog surveillance cameras still occupy a large market share, high-definition network surveillance cameras are developing rapidly and will definitely become the absolute mainstream of the surveillance market in the next few years. In the past few years, CMOS sensor technology is still immature. CCD has been widely used in analog surveillance cameras of various mainstream manufacturers with its excellent imaging quality, mature technology, stable performance and excellent night vision capabilities. In recent years, with the development of CMOS technology and the continuous optimization of the manufacturing process, the photosensitive performance and signal-to-noise ratio have been greatly improved, and the gap with CCD is gradually narrowing. Especially in the high-definition network monitoring program, CMOS has some advantages that are unmatched by CCD. 1. Cost The CCD has a complicated structure and requires very high processing technology. At present, only a few manufacturers can master the production technology of CCD. CMOS uses the MOS process commonly used in the semiconductor industry, and its production process can be continuously improved and optimized with the continuous development of traditional semiconductor processes, making the cost lower and lower. 2. Speed CCD charge coupler needs to be controlled by a synchronous clock, all charges are output from a single channel, and the speed is slow; while CMOS photoelectric sensors can pick up electrical signals while collecting optical signals, and can also process image information of each unit at a faster speed CCD charge couplers are much faster. It has absolute advantages for high resolution and high frame rate processing. 3. Power consumption CCD charge couplers require multiple voltages to transfer signal charges, and generally require higher voltages to drive charge movement, while CMOS photoelectric sensors require only one Power Supply, and their power consumption is only 1/8 ~ 1/10 of CCD charge couplers. It has great advantages in power consumption, and the requirements for the heat dissipation structure of the product are also reduced. 4. Volume The peripheral circuit of the CCD sensor is more complicated, and the CMOS sensor integrates all the logic and control circuits inside the chip. The integration is high and the volume is small, which is conducive to the miniaturization of the device. It is precisely because of the above advantages of CMOS that it can become the first choice for high-definition IPC with the wave of networking in the security industry, breaking the monopoly position of CCD in the analog era. It can be said that the future demand of the high-definition network monitoring market also determines the development direction of CMOS in the field of security. There are mainly the following trends: 1. Higher resolution and frame rate HD is divided into three levels, quasi-HD 720P, the actual resolution is 1280 × 720, effective pixels 920,000, usually called megapixels; Full HD 1080P, the actual resolution is 1920 × 1080, effective pixels 2.07 million, usually It is called two megapixels; the highest-end mainstream UHD resolution is 2560 × 1920, with 4.92 million effective pixels, usually called five megapixels. At present, the most common ones on the market are 720P and 1080P, which occupy most of the high-definition IPC market. Among them, 720P has become the absolute mainstream with its low cost advantage. With the continuous development of the entire information industry, network bandwidth is getting higher and higher, Gigabit Ethernet and fiber are gradually popularized, and more and more display devices support 1080P. Therefore, in the next few years, two million 1080P network surveillance cameras can be foreseen The proportion of will gradually increase, and the demand for higher resolution and higher frame rate will become stronger, which requires CMOS to support high-speed output. With the development of semiconductor technology, the size of CMOS single pixel has been reduced year by year, making the resolution can be made larger at the same size, and SENSOR can be made smaller. Now the resolution of CMOS sensors used in the photography industry is more than 10 million pixels Therefore, it is not difficult to increase the resolution of high-definition IPCs. The difficulty lies in the ability to keep up with the back-end image processing, data compression, network transmission, video storage and other supporting links in the case of high resolution and high frame rate. 2. Better low light effect The quality of the low-light effect directly affects the image effect at night. The high-definition era not only requires that you can see clearly during the day, but also needs to be able to output high-quality images at night. In previous years, compared with CCD, low light sensitivity and noise control have been the disadvantages of CMOS. In recent years, through the use of new technologies, the level of low-light photography of CMOS has been continuously improved, and has reached or even exceeded CCD. Reverse the silicon substrate surface technology, that is, back-illuminated CMOS technology. By changing the wiring position of the light-receiving surface above the traditional photosensitive module substrate and placing it behind (below) the substrate, the light will not be affected by the interference of wiring, transistors, etc., increasing the amount of light incident, making The light receiving condition of a single pixel is better, and the effect of low light is greatly improved. This technology was first proposed and actually applied by SONY, and has now been widely adopted by various CMOS manufacturers. Although the implementation details are different between the companies, the principle is the same. Stacked CMOS technology, the next-generation back-illuminated technology SONY claims. The difference from the traditional process design is that it uses the stacking method to place the circuit part that needs to be close to the photosensitive element under the photosensitive element. This approach can make the entire assembly get more under the same size specifications To get a larger area of ​​light sensitivity, and benefiting from this design, the design of the support substrate that needs to add a support chip to support the entire chip under the component has been cancelled because of the large overall area. Reduce the complexity of component manufacturing, and let CMOS chip size shrink further. 3. Wide dynamic technology The wide dynamic technology is a technology that allows the camera to see the details of the bright and dark places at the same time when the contrast between light and dark is strong. It is widely used in actual surveillance scenarios. For example, the garage entrance, looking at the scene outside the window during the day, etc. In addition to relying on the back-end image processing technology, the improvement of the wide dynamic technology is also important to improve the dynamic range of SENSOR itself. Due to the inherent characteristics of CCD, even with multiple exposures, the wide dynamic range of the CCD camera is only 66dB at most, and the dynamic range of the CMOS wide dynamic camera can reach 160dB under the existing technology. The mainstream wide dynamic CMOS on the market There are SONY's IMX222 and Aptina's 9M034, etc. The S3E series IPC launched by Tiandi Weiye adopts this technology to improve the wide dynamic effect of the camera. In addition, CMOS-DPS technology is more worthy of attention in the future. CMOS-DPS is the CMOS digital pixel sensor technology. Unlike traditional CMOS sensors, each pixel of CMOS-DPS contains an independent AD Converter, and uses 32-bit ARM to accurately control each pixel, so that each pixel independently completes sampling. And exposure, and directly converted into digital signals, is currently the only true digital image processing system on the market. Some international mainstream manufacturers have launched ultra-wide dynamic cameras using this technology. The wide dynamic technology has extremely strong use value in the monitoring field, and will surely become the standard configuration of high-definition IPC in the future. 4. Low-cost megapixel HD solution Networking has allowed security monitoring to rapidly expand from the previous professional market to the ordinary civilian consumer market, and security monitoring products have become more sensitive to prices. Megapixel IPC came into being in this environment. It meets the basic requirements of users for high-definition IPC: 720P high-definition, network transmission control, and low cost. At present, the megapixel high-definition cameras on the security market generally use 1 / 4-inch ultra-low-cost CMOS, and the overall cost can be controlled at a level that is not much different from ordinary standard-definition analog cameras. However, due to the limitation of the size and cost of the sensor, the low-light effect of megapixels is relatively general, and the noise control is poor, which belongs to the entry-level product in the high-definition IPC market. Individuals estimate that it is only a transitional product, and it will gradually lose its advantages as the cost of 1.3 million and 2 million products decreases in the near future, and will eventually be replaced. With the improvement of surveillance technology and the continuous development of industry applications, the market position of high-definition network cameras has rapidly increased, and it will face more changes in technology. Similarly, in order to meet the needs of the market, the CMOS image sensor as the core of high-definition network cameras will also be constantly improved and developed. Only continuous progress can guarantee its own dominant position and development space, otherwise it will only be eliminated by the market. Shenzhen Yidashun Technology Co., Ltd. , https://www.ydsadapter.com