Abstract: A machine-readable record or label includes alternating areas of different reflectivity providing a binary coded data record. The record is made by selecting the widths of the areas such that an increase in the relative widths of any two consecutive areas of like characteristics represents a binary "1" and a decrease in the relative widths of any two consecutive like areas represents a binary "0". Thus, each area in a part of the code is used in the establishment of the values of two different binary bits. A method of and system for reading or interpreting the record or label includes two pairs of light reader controlled registers in one pair of which bar widths are stored and in the other pair of which space widths are stored. In each pair, the widths of consecutive like areas are alternately stored. A sequence control steers successive width signals from the reader into a proper register in a proper register pair.

Abstract: There is disclosed apparatus for scanning a concave coded record which is adapted to be disposed in the inside of an open-ended tube. A rotor carries a source of illumination which illuminates the record. Light reflected from the record is reflected onto a mirror carried by the rotor and passes along the axis of rotation of the rotor through a suitable lens or lenses and is focused on a mask. The mask has an aperture through which light passes to a light receptor such as a photodetector. The light receptor is stationarily mounted to the frame. The frame also mounts a motor for driving the rotor and bearings for rotatably mounting the rotor. A cover adapted to abut the end of the tube is mounted for movement between one position in which the cover is in the reflected light path and another position in which the cover is out of the reflected light path.