Reading apparatus for reading colored markings applied to objects

Abstract

Colored markings such as a series of colored rings applied to an ampoule are read by causing the ampoule to move beneath an illuminating system which projects white light at the colored markings. Light reflected or scattered from the colored markings is directed at an aperture member arranged in the field of view of a color sensitive photoelectric detector arrangement and the image of the colored markings moves in a first direction across this aperture member due to relative movement of the object. The aperture member has a series of spaced apart optical apertures which are sequentially moved in a second direction transverse to the first direction and in front of the photoelectric detector arrangement. The photoelectric detector arrangement produces signals corresponding to the transmission of the image of the colored markings through the optical apertures. The series of optical apertures includes read apertures for generating the afore-mentioned signals and recognition apertures which are of a smaller size and which are operative to generate further signals allowing the read signals to be recognized only when the object is centrally located in the field of view of the optical system. Read signals occurring during this time are subsequently processed to detect whether or not the correct sequence of colored markings is present.