Video door-phone (also known as video door entry or video intercom) is a stand-alone intercom system used to manage calls made at the entrance to a building (residential complex, detached family home, workplace, etc.) with access controlled by audiovisual communication between the inside and outside. The main feature of video door entry is that it enables the person indoors to identify the visitor and, if (and only if) they wish, engage in conversation and/or open the door to allow access to the person calling.
Video door entry consists of both outside and indoor elements: an outdoor panel on the outside, an electronic lock release and an indoor monitor. The outdoor panel or street panel is installed beside the entrance door or gateway and incorporates different elements ready for use in any climate conditions: one or several pushbuttons to make the call (usually one per home or apartment), a micro camera adapted for night vision to capture the image of the caller, a microphone to pick up their voice and a speaker to reproduce the voice of the occupant indoors. A video door entry panel may include push buttons to call the homes or offices and a camera to capture the street scene. The video entry monitor allows the occupant to see who has called, talk to the visitor and open the door. Installed indoors, the monitor consists of a screen showing the image of the person calling, a microphone and earpiece for conversation and a pushbutton to trigger the door lock release. The communication set up is full duplex. The electric door release is a device installed in the door lock and operated from inside the building to lift the latch and clear the way for the visitor.