IP Camera Modules for security surveillance can be divided intothe zoom camera module and fixed focal length camera module according to whether they can be zoomed or not.
The design of a fixed focal length lens is much simpler than that of a zoom lens, and generally only requires an aperture drive motor. Inside a zoom lens, in addition to the aperture drive motor, we also need an optical zoom drive motor and a focus drive motor, so the dimensions of a zoom lens are generally larger than a fixed focal length lens, as shown in Figure 1 below.
Figure1 Differences between the Internal structure of a zoom lens (The top one) and a fixed focal length lens (The bottom one)
Zoom camera modules can be further divided into three types, namely manual lens cameras, motorized zoom lens cameras, and integrated zoom cameras(zoom block camera).
Manual lens cameras have many limitations when used, making their use in the security monitoring industry increasingly rare.
The motorized zoom lens camera uses a motorized zoom lens with a C/CS mount, which can be used with a general bullet camera or with a proprietary imaging module to make a product such as a dome camera. The camera receives commands for zoom, focus and iris from the network port and then can control the lens directly. The external structure of the general bullet is shown in Figure 2 below. 
Figure 2 The bullet camera
Motorized varifocal camera solves the disadvantage of fixed-focus camera monitoring distance, but also has some inherent flaws:
1. Poor focusing performance. As the motorised varifocal lens is gear driven, this results in poor control accuracy.
2.Reliability is not good. The motor of the motorized varifocal lens has an endurance life of up to 100,000 cycles, which is not suitable for scenarios that require frequent zooms such as AI recognition.
3. Volume and weight are not advantageous. Electric zoom lens in order to save costs, will not use multiple groups of linkage and other complex optical technology, so the lens volume is large and heavy weight.
4.Integration difficulties. Conventional products usually have limited functions and cannot meet the complex customization requirements of third-party integrators.
In order to compensate for the shortcomings of the mentioned cameras, zoom block camera modules have been created. The integrated zoom camera modules adopt stepper motor drive, which is quick to focus; it adopts optocoupler as the basis for determining the zero position of the lens, with high positioning accuracy; the stepper motors have an endurance life of millions of times, with high reliability; therefore, it adopts multi-group linkage and integrated technology, with small volume and light weight. The integrated movement solves all the above pain points of the gun machine, so it is widely used in high-speed ball, drone pods and other products, applied in safe city, border surveillance, search and rescue, power patrol and other industry applications.
In addition, our telephoto lenses use multi-group linkage mechanism, as shown in Figure 3 below; the focal lengths of the telephoto segments are controlled by different lens groups separately, with each zoom and focus motor cooperating with each other. The dimensions and weight of the integrated zoom camera modules are greatly reduced while ensuring precise focusing and zooming.
Figure 3 Multi-group linked telephoto lenses
Thanks to the integrated design, the 3A, the most central function of the integrated zoom camera module, is achieved: Auto Exposure, Auto White Balance and Auto Focus.
Post time: Mar-14-2022