Photoelectric apparatus for tracing a scanning head along a pattern track with selectable sampling

In a photoelectric apparatus for tracing a scanning head (8) along a pattern track (13), a constant arrangement (17) of tightly spaced light-sensitive elements (16) is provided in the scanning head forming together with an addressing device (25) scanning patterns (14) which can be sampled. On the arrangement of the light-sensitive elements, a section of a pattern plane for scanning including an essential transversal component of the scanning pattern is imaged. From illumination state signals of the sampled light-sensitive elements, control signals are generated by means of an evaluation device (28, 31, 32), controlling the tracing movement of the scanning head in two movement directions (4, 5) rectangularly oriented relative to each other. The shape and/or the position of the scanning pattern (14) in the scanning head scanning the pattern track (13) may be varied by selective sampling of determined light-sensitive elements from a greater number of light-sensitive elements (16) provided in the constant area-like arrangement (17).