Patent ID: 8099902

Claim:
A sensor arrangement for controlling opening and closing of a door device, said sensor arrangement being arranged to be mounted in a vicinity of the door device, said sensor arrangement comprising an image-acquiring means, which is arranged to be mounted in a viewing position wherein said image-acquiring means monitors a field of view that encompasses at least an approach area located adjacent said door device, said image-acquiring means being adapted to acquire images of said field of view, a movement detector, which is arranged to receive said acquired images and which is arranged to process the received images in order to detect a movement, which is to result in an opening of the door device, and an event generator, which is arranged to receive information regarding said door device and said field of view, said information comprising said acquired images, said event generator being arranged to process said information in order to identify at least one event according to predetermined criteria, said at least one event pertaining to exceptional situations excluded from normal operation of said sensor arrangement, said exceptional situations being defined by said predetermined criteria, wherein the event generator creates a permanent recording of the event in response to an identification of the event, and wherein the event generator creates a temporarily buffered recording during normal operation of said sensor arrangement.