Process Date: January 2001

128 Code, marked with an FH-Series Marking Head and 25W Synrad laser.  Marking speed was 35" per second.

Magnified view of a code made up of linear spots.
A new milestone in the development of glass marking techniques has been reached - marking readable 1-D bar codes on glass! Because bar codes require about 80% contrast to read, they are more challenging to produce on many materials, including glass. However, we have found that consistent, readable bar codes can be produced using two techniques - by marking solid lines, or by creating lines of closely spaced spots.

Generally, the method of marking continuous lines is used on glass with a smooth surface finish, and the "spot" technique with less pristine surface finishes. The use of spots also aids illumination by increasing the scattering of light as it is refracted through the mark. Although the codes require a vision system to be read, set-up is straightforward with illumination provided by a luminescent lamp. In this instance, the reading software used was RVSI Acuity CiMatrix.

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