Reading system for tags encoded with bars of different widths

Abstract

Abstract A device for reading information encoded in the form of bars of two widths. The device comprises an illuminating section for illuminating the bars and concentric detecting sections corresponding respectively in width to the width of the aforementioned bars. The detectors are physically related to the illuminating portion to detect the illumination of the bars thereby. The detectors may be optical fiber bundles. The innermost of the detectors is preferably columnar. A method of the invention consists of translating a row of bars of different widths into information bits by scanning the bars to illuminate the same and to pick up reflected light with two associated light detectors, the widths of which correspond, as noted above, to the width of the bars. The picked up light by the detectors is converted into electrical pulses, the magnitude of which is limited to form rectangular pulses of width corresponding to the aforesaid bars. The magnitude of the pulses generated by the wider detector is detected to generate pulses correponding only to the wider bars. The latter pulses are terminated in synchronism with the corresponding rectangular pulses. The bars are preferably made of one color.

Inventors

• 👤 K Nakamura

Bibliographic Details