The development trend of HD lens

With the development of hdcvi technology and high-definition network camera IPC which began to be popular in the past few years, the front-end camera has gradually developed from the initial standard definition to high-definition and ultra-high-definition. Not only has the breakthrough progress in pixel, but also the imaging quality of lens has been concerned. Now with the advent of 265 high-efficiency compression coding and decoding technology, 4K high-definition picture that was not available at the beginning can be realized and continuously matured. This major breakthrough in transmission technology has shattered the calm of camera high-definition imaging, and at the same time, it has once again provided an extremely broad development environment for camera front-end lens head. During this period, a large number of ultra-high-definition and high-quality pictures have been produced Lenses are springing up in the market, and the pixel and imaging quality of industrial security cameras are directly approaching that of civil SLR cameras.
The optical system of the security camera is a typical traditional imaging optical system, which is mainly composed of an image sensor, a lens and a focusing mechanism. The external light is received by the lens and transmitted to the sensor surface. The optical signal is transformed into an electrical signal by the sensor and transmitted to the back-end processing, which is finally reflected in the display. Therefore, as the front end of the camera, the external light received by the camera is the first-hand information received by the camera, so it can be seen that the role of the camera plays an important role.
development direction
I. driven development
As the front end of the camera, the importance of lens need not be discussed. 265 efficient compression and decoding technology and 4K high-definition imaging technology break the bottleneck of a new stage of ultra-high-definition imaging, and the door of ultra-high-definition imaging opens at the same time, which also puts forward a higher new demand for the optical system of security camera; 4 / 3 inch large target image sensor with 12 million pixels is on the market, which indicates that the security lens market is about to be updated.
1. High definition picture frame and ultra-high pixel.
With the arrival of the era of large target area sensor, the concept of ultra-high pixel has been upgraded to a higher level. The 4 / 3 inch effective imaging area carrying 12 million pixel image sensor has been widely used in intelligent transportation, safe city and other important fields; 265 high-efficiency compression coding technology is also mature in the continuous test; and 4K imaging technology also brings long-term expectations to the market and users Amazing effect. The breakthrough of the above transmission and imaging technology and the advent of large target sensor have also put forward the demand of high-resolution lens. Resolution refers to the ability of the lens to reproduce the details of the subject. The higher the resolution is, the clearer and more delicate the picture will be. Contrast refers to the ability to reproduce the contrast details and light and dark levels of the subject. The higher the contrast is, the sharper the outline, edge, level, texture and tone of the picture will be. The lens with high resolution and low contrast, the image outline is not clear, the contrast is gray and the tone is flat, which makes people feel that it is not clear.

2. Large pixel, low noise
The large target area of high-definition picture frame not only brings us high-pixel picture quality experience, but also more importantly
It is the large target sensor that provides more space for each pixel; compared with the previous small pixel size sensor, the large pixel can receive more light, and the light of each band can be more transmitted to pixel, which makes the picture more colorful; moreover, the large space of the large pixel gives the sensor a precious opportunity to upgrade the production process, and the large pixel receives more light With the increase of effective light, the signal-to-noise ratio of sensor will be greatly improved, which also provides a powerful guarantee for front-end image acquisition.
3. Large aperture, variable aperture
Nowadays, the security monitoring is becoming more and more high-definition and network-based, and the application of security cameras is more and more extensive. Many places with poor monitoring conditions, dim light and changeable conditions need to be installed with various cameras, especially to meet the environmental conditions of 24-hour monitoring. For night and other ultra-low illumination environment, if the lens does not collect enough light, it will cause the picture to be dark or even completely black, which seriously affects the definition.  The super aperture lens is one of the key technologies to improve the low illumination performance of the camera.
In case of the environment where the light changes frequently, such as the license plate recognition camera at the garage door is often illuminated by the traffic lights, the variable aperture can be selected, and the aperture size can be adjusted at any time according to the different external light environment, so the future large aperture and the variable aperture of the new situation are still the future development direction of the lens.
4. Night monitoring
At present, the security monitoring industry pays more and more attention to the monitoring effect of low illumination or zero illumination at night. At present, many products need to rely on flash to supplement light for shooting in low illumination or zero illumination environment, while flash is not allowed in many countries, so they need to rely more on the support of large pixel sensor, large aperture lens and back-end image processing.
At the same time, on the premise of ensuring the image quality during the day, the function of infrared filter can be used. Ed (low refractive index and high dispersion coefficient) glass can better correct the color difference and improve the confocal ability and image quality of day and night imaging. In recent years, major glass manufacturers are also trying to promote ed glass.
5. Super wide angle, large field of view
Security industry is developing towards high definition, network and intelligence.  Large screen panoramic splicing
At present, the technology has attracted much attention, that is to say, the images captured by multiple cameras are processed by image algorithm and spliced to make it a picture, so as to give people a panoramic observation experience. In the actual project, the location, angle and number of cameras directly affect the panoramic imaging