Laser scanners struggle to read poor quality barcodes in high speed logistics applications
Cognex DataMan and MX series of industrial, image-based barcode readers decode 1-D and 2-D codes, from printed labels to the hardest to read direct part mark (DPM) codes, and deliver industry-leading read rates.
Matt Engle, 04-24-2012
Traditional laser scanners can only provide high read rates with good-quality printed barcodes when labels are undamaged. But barcode quality can vary dramatically depending on the amount that the package is handled, the printing technology, label geometry, point of origin and a host of other factors. Poor contrast, for example, may not provide enough difference between a printed and unprinted line to get an accurate read.
Because a laser scanner attempts to decipher the code along a single laser line, ambient light or specular reflections may also reduce the laser scanner’s ability to read the code successfully. Some laser scanners attempt to solve this issue by “stitching” multiple scan lines together to reconstruct a damaged barcode. This method works well in some cases, but not when damage is severe. Area-array image-based readers, however, take snapshots of the codes, like digital cameras, and use advanced decoding algorithms to decipher what’s captured in the image. Imager algorithms rarely fail, reading codes of all levels of damage and orientation and achieving six sigma read rates.