Picture scanner with a scanning light position detector

Claim 1

A picture scanner with a scanning light position detector comprising: an original picture cylinder rotatable around its axis; a light projector for scanning an original picture attached on the surface of the original picture cylinder, including in series along its optical axis a light source, a first projecting lens, a mask plate having an aperture, and a second projecting lens; and a scanning head which receives a light beam from the original picture and includes in series a pick-up lens and a photoelectric transducer element on its optical axis; wherein a pivot mirror and a screen are provided, and the pivot mirror is arranged between the pick-up lens and the photoelectric transducer element and can be pivoted into the optical axis of the scanning head so as to divert the light beam onto the screen, and wherein the first projecting lens is movable in the axial direction of the light projector over a range including two positions, in one of which the first projecting lens forms an image of the light source at the focal point in front of the second projecting lens, said position being the normal operating position, and in the other position of which the first projecting lens forms an image of the light source in the plane of the mask plate, said other position being for lateral adjustment of the source, thus allowing an image of the light source superimposed on the mask to be projected onto the screen when the mirror is pivoted to the position where it diverts the light beam onto the screen.