| 摘要 |
PCT No. PCT/EP93/01659 Sec. 371 Date Jan. 25, 1995 Sec. 102(e) Date Jan. 25, 1995 PCT Filed Jun. 29, 1993 PCT Pub. No. WO94/01043 PCT Pub. Date Jan. 20, 1994The invention relates to a method and an apparatus for determining the authenticity and/or for identifying the respective spatial structure of a test specimen. The test specimen is placed on a surface and is exposed to ultrasonic waves traversing a body contiguous with the surface and the waves reflected and/or backscattered by the test specimen reproduce a different structure for different test specimens which are evaluated. It is characteristic of the method according to the invention that provided in the body (4) is a layer or surface (6) which is transparent to the ultrasonic waves and reflects and/or diffracts electromagnetic waves, that the layer or surface (6) in the body (4) is deformed in a locally different and time-dependent way by the ultrasonic waves according to the form and intensity of the backscattered or diffracted ultrasonic waves, and that the layer (6) is exposed to radiation of electromagnetic waves at an angle and in the area of the electromagnetic beams reflected and/or diffracted at the angle of emergence (9) the same are intercepted and their change caused by their reflection or diffraction at the layer (6) is evaluated. To carry out this method, the apparatus according to the invention is formed with the layer (6) arranged in the body (4) and the apparatus (1) has an electromagnetic radiation source (7), the beams of which are directed to the layer (6), and that at least one beam receiver (8) is provided in the area of the reflected or diffracted electromagnetic beam and serves to evaluate the beam (single FIGURE). |
