Device for optical inspection of documents (3, 22, 103, 113, 133), with a
light source (9, 79, 119), an
observation unit (1, 91, 101, 111; 121, 131) which has a window (2a, 2c; 92, 102; 122) through which the light emitted by the
light source (9, 79, 119) for the examination of the documents (3, 22, 103, 113, 133) by an observer (11) exits, and a
coupling unit (14, 14a) to introduce the light emitted from the
light source (9, 79, 119) from outside into the
observation unit (1, 91, 101, 111; 121, 131), characterized by the fact that the window (2a, 2c; 92, 102; 122) contains a fluorescent substance, and the window is formed by a support plate (2a, 2c; 92, 102; 122) which is suitable for supporting the document to be examined (3, 22, 103, 113, 133) in order to transmit the light emerging from the window through the document (3, 22, 103, 113, 133) towards the observer (11).