To provide a method and an apparatus wherein the position of a moving material such as a conveyor belt or the like which is partly transparent over the whole is detected and, when a deviation is generated, the position can be corrected according to a desired position.
The method and the apparatus are related to a method and an apparatus for the detection of the position of a material, wherein light (2) is directed to a region in the end (3) of the material (1), the jump of the intensity of the light (2) and that of light (2') generated when the material is partly inserted into an optical path (2) are detected, and the jumps are evaluated in order to decide the position of the material. The method and the apparatus have an effect capable of detecting the position of the material with high accuracy even in the case of a transparent material in such a way that polarized light with reference to the light is supplied, that at least beams of partially reflected light (2', 2", 2''', 2'''') are generated and that the optical path is directed to boundary faces (7, 7') of the material so as to detect the jump of the intensity of the light generated by the beams of partially reflected light. The controller which controls the position of the moving material is installed according to the detection of the position.
KARL-HEINZ PETER
SPILZ ROLF
