Abstract: A network camera that connects a plurality of extensible imagers includes at least one imaging module and a camera body. The at least one imaging module includes a lens, an image sensor, an image digital signal processor with a video encoder and a USB connecting line. The camera body includes a plurality of USB ports for the USB signal line of the at least one imaging module to insert therein, a CPU and at least one signal output interface. The image sensor captures a digital image via the lens. The digital image is processed by the image digital signal processor and the video encoder and transmitted to the camera body via the USB connecting line. The digital image is further processed by computations of the CPU to form required signals outputted via the signal output interface.

Abstract: The present invention discloses an auxiliary focusing system for an IP camera. The auxiliary focusing system utilizes an image sensor module to determine whether the focusing is accomplished. Display devices (such as indicator lights, displays) and audio devices (such as buzzers, speakers) are used to inform a user whether the images have been focused clearly.