Many printed products such as currency, tickets, commercial publications, newspaper, pharmaceutical, and food packaging, etc require 100% print inspection (often in color) as part of their quality control process; many require this inspection multiple times during production.
Print can be on any materials like paper, metal, Glass, Plastic, Ceramic, PCB and many more. All these materials have different properties like stretchable, flexible and deformable, hence visual appearance also varies. Defects can be of different forms and types. Below are the some of the examples of print defects Print inconsistency, Print Growth (Smaller or Larger), Reflectance, Damage or Distortion, Quite Zone Violation, Grid Non-Uniformity, Modulation and many more.
We are checking for a print defect on the stickers for one of our customer. Stickers are moving on the conveyor belt and are randomly distributed.
A sensor is used to detect the presence/arrival of the sticker on a conveyor belt. It triggers the camera by a pulse and image is captured. Line Scan Camera is connected via GigE port to a PC, which in turn communicates with I/O through a serial port.
Once the image is captured. The system checks for any print defects on the sticker and the software now sends a ‘Pass’ signal or ‘Fail’ signal accordingly.
The images shown below are some of the samples of defects that are identified using this software
Using area scan cameras, we can image the surface of this Sticker and detect very reliably any print defects that are present.
