The invention relates, among other things, to a door sensor device (20) for mounting on a door element (10), more particularly a swing door, which can be rotated about an axis of rotation (D), having at least one transmission device (21) for generating at least one monitoring beam (S) in the direction of the floor, said beam being oriented at an angle to the door leaf plane (E) of the door element (10), at least one receiving device (22) for receiving reflected or back-scattered radiation, and an evaluation device (23) for evaluating the radiation received by the receiving device (22) and generating an object detection signal. According to the invention, the evaluation device (23) is designed such that it checks whether a predefined exclusion condition is met, wherein the exclusion condition is dependent on at least three values, specifically an angle value specifying the rotational angle of the door element (10), a maximum value predefined for the evaluation device (23), said maximum value specifying a fixed, maximum permitted rotational angle of the door element (10), and a measuring-point-specific advance angle value, which specifies the angle between a section which is bounded by the measuring point (M1-Mn) formed by the monitoring beam (S) on the floor and the axis of rotation (D) of the door element (10), and the door leaf plane (E).