Method and device for checking a secured document

An optical checking method, for authentication of a secured object, with a handheld checking device provided with a processor or a micro-processor and a display screen;

• said secured object being provided with at least an optically variable security element, which generates optical effects according to the orientation or movement thereof with respect to an optical sensor, said method comprising the steps of:
• providing said handheld checking device with a module comprising a position or a motion sensor for measuring the orientation or the movement of said module;
• measuring the orientation or the movements of said handheld checking device with said position or motion sensor;
• communicating said measured orientation or movements to said processor or micro-processor in real time;
• integrating in said processor or micro-processor said measured orientation or movements to determine a shape of a simulation of a nominal security element associated with said secured object to be displayed;
• displaying, on said display screen, said simulation based on the measured movement or the orientation of said handheld checking device determined by said position or motion sensor integrated to it,
• dynamically applying identical movements simultaneously to both said module and to said optically variable security element,
• capturing images of both said simulation of a nominal security element and said optically variable security element with said optical sensor while being applied identical movements,
• retrieving images from said optical sensor, and
• comparing, at each instant during the applied movements, the optical effects of the optically variable security element with those of the simulation of the nominal security element on the display screen of said handheld checking device when the orientation or the movement of the secured object and the module with respect to said optical sensor are the same.