System for reading information code and medium on which information code is formed

摘要

A system reads an information code formed on a medium. The code has light modules and dark modules. The areas of the light modules are produced as inversion areas inverted light reflection characteristics. The areas of the dark module areas are produced as non-inversion areas non-inverting light reflection characteristics. A reader emits illumination light of wavelengths including infrared light wavelengths to the code, and images the code under the illumining light emission. The inversion areas, that is, the light module areas, can be dark under the visible light, but can be a light color due to its inverted light reflection characteristics. The light modules can thus be imaged by the reader under the illumining light emission, providing distinguishable detection of the inversion and non-inversion areas, allowing the light and dark modules to be extracted for decoding.

主权项

1. A system for reading an information code, comprising:
a reader; and a medium on or in which an information code is formed, the information code having light modules and dark modules, wherein the reader comprises: illuminating means for emitting illumination light; imaging means for imaging the medium to which the illumination light is emitted by the illuminating means; and decoding means for extracting and decoding the information code from an image of the medium obtained by the imaging means, wherein the medium has inversion areas and non-inversion areas, the inversion areas i) presenting reflection characteristics on one of a dark color and a light color when light of a first wavelength band including at least a visible light band is emitted to the medium and ii) presenting reflection characteristics on the other of the dark color and the light color when light of a second wavelength band different in wavelengths from the first wavelength band is emitted to the medium, the non-inversion areas iii) presenting the reflection characteristics on the one of the dark color and the light color when the light of the first wavelength band is emitted to the medium and iv) representing the reflection characteristics on the one of the dark color and the light color when the light of the second wavelength band is emitted to the medium, both the inversion areas and the dark modules presenting the same color when the light of the first wavelength band is emitted to the medium; either the light modules or the dark modules of the code is arranged as one of the inversion areas and the non-inversion areas, and the other of the light modules and the dark modules of the code is arranged as the other of the inversion areas and the non-inversion areas; the illuminating means includes a second illumination light emitting means emitting the illumination light of the second wavelength band toward the medium; the imaging means is configured to image the medium in a state where the light of the second wavelength band is emitted to the medium; and the decoding means is configured to detect, from the image, the inversion areas and the non-inversion areas differentiatedly so as to extract the areas of the light modules and the dark modules and to decode the information code based on extracted results.