Means and method for non-contact bar code label verification

摘要

A portable, conveniently usable, and inexpensive non-contact bar code verifier permits testing of bar code labels at some arbitrary but constant distance from the verifier. Means are provided for analog analysis of bar code label contrast levels, and for derivation of new, instructive indices characterizing the readability and print quality. Additionally, a new method for determination of absolute bar code label dimensions is disclosed. The method of calibration for arbitrary scanning distance and angle standardizes not only the verifier's ability to measure absolute dimensions at unknown distances, but also its ability to discern contrast under arbitrary lighting conditions and scanning equipment. This is accomplished by employing calibration standards of known characteristics. Bar code verification information may be stored and/or employed for a variety of control and analytical functions as recognized in the art.