摘要 |
Apparatus for reading code elements (113) which are relieved from a container (111). A source of light (170) projects normally at the code elements (113) while the container (111) is rotated by wheel (97) to sequentially illuminate each of the code elements (113). A sensor (140) receives light which is reflected approximately normal to the surface of the container (111) but avoids light which is reflected from the surface of each code element (113) at an appreciable angle relative to the normal. The intensity of the reflections from regions of said container (111) not containing a code element (113) are relatively large compared to reflections received from portions of the container surface containing a code element (113) and a threshold is set therebetween. |