Security element for the identification of a security document and process for their production.

Security element (1, 1 ', 1' ', 1' ', 1' ', 1' '') for identifying a security document (100), in particular a banknote, a value or a paper document, at least one display element can be controlled electrically (1b) and at least one piezoelectric energy source (1a) controlling at least one display element (1b) it is provided that the security element (1, 1 ', 1' ', 1' ', 1' ', 1' '') is formed by a body of flexible multilayer sheet, comprising at least a display element can be controlled electrically (1b) containing a display layer (5) with liquid crystals that can be oriented in an electric field and at least one piezoelectric energy source (1a) controlling at least one display element (1b) with at least one layer (4) of piezoelectric material, characterized in that the security element (1, 1 ', 1' ', 1' ', 1' ' , 1 '' ') has a thickness of at most 70 microns in perpendicular to the plane of the film body direction, and the film body has a first optional carrier film (2), a first electrode layer (3a ) formed at least in regions, a layer (4) of piezoelectric material formed by regions on the first electrode layer (3a) and a display layer (5) formed in regions and in the same plane on the first electrode layer (3a), also a layer of transparent adhesive optionally (7) formed at least in regions, a second transparent electrode layer (3b) formed at least in regions and optionally a transparent protective layer (8).