Table of Contents
Advertisement
Specifications:
All bar code symbols should satisfy the appropriate AIM Uniform
Symbology Specification.
Background Substrate:
The bar code symbol should be printed on material that is reflective and
has a matte (not glossy) finish. A background diffuse reflectance of at
least 70% to 80% is desirable for optimum contrast.
Ink Color and Type:
The inked bars should not exceed 25% reflectance at the wavelength that
is being used for reading, whether printed with black ink or colored ink.
The reflectance value should not vary more than 5% within the same
character.
Voids and Specks:
The code should be printed clearly, free of voids, specks, blemishes and
lines that could "fool" the scanner. Specks or blemishes in the white
spaces, or false or missing bar sections, could be interpreted by the
reading equipment as part of the code. Generally, the width of such
flaws is more serious than the height. Code symbols should be rejected
if these defects are present.
Definition:
The bars in the bar code symbol should be well defined. Their edges
should not be rough or fuzzy, so that the bars and spaces have the proper
widths intended for the bar code symbology used.
Contrast:
Background reflectance (that of the substrate on which the codes are
printed) should always provide a good contrast relative to the ink
reflectance (that of the code bars). The difference between the two
should be at least 37.5% at the wavelength used for reading.
Tolerance:
The ration of the widths of bars and spaces in a bar code symbol must
conform to the appropriate AIM bar code specifications and can cause
problems if not correct throughout the bar code. Problems can occur
when bar edges are smeared or rough, or when they exhibit voids.
APPENDIX A: SPECIFICATIONS | 29
Advertisement
Table of Contents
