Patent ID: 8857572

Claim:
An elevator device for transporting persons and/or objects within an elevator shaft of a building comprising at least two levels, said elevator device comprising: an elevator car, in which the persons and/or objects to be transported can be accommodated; a running framework including a guiding rail for mounting and guiding the elevator car; a position determining device for determining the position of the elevator car within the elevator shaft and/or with respect to the running framework, which device comprises first and second marking units for marking the position of the elevator car, a detection unit for detecting and/or reading out the marking unit and an evaluation unit for evaluating measured values of the detection unit, wherein the marking units are formed as a carrier of a 2D barcode and the detection unit is formed as a camera, wherein the first marking unit is attached on the guiding rail of the running framework, wherein the second marking unit is attached on one of the elevator shaft and a wall of the building, the second marking unit is in the form of a reference marking for comparing the accuracy of the first marking unit, and the evaluation unit is configured to make a comparison between the first and second marking units to establish whether there is a change in relation to the relative position between the first marking unit and the second marking unit.