Vision Inspection Systems
Vision technology is used to detect defects in manufactured goods in real time. Using high speed vision sensors and controllers it is possible to detect, reject and prevent unabated production of non conformance finished goods.
Code Presence Detection – OCR / OCV
Production codes, lot numbers and best before dates are all essential on consumer goods. It is important that each product features a clear, legible and accurate code.
Operating at high speed a vision sensor is a camera which literally snapshots each product and identifies defects. If the system has been programmed to check for the presence of a date code the it will quickly process the captured image and verify if the code is present or not. If the code is distorted beyond recognition, fully or partly missing the system will consider it a NO GOOD sample and activate the reject command. Consecutive rejects may signify a systemic failure and shut down the line for corrective action to be taken by alerted staff.
Simple verification of code presence is suitable for some applications. For those that must verify the data content of each print the OCV and OCR tools play a key role. If for example we must confirm that the printer has printed the correct date the camera and controller will analise the captured image and output the captured alpha numeric data. The external control system will be expecting to see a particular date and if that is the data returned by the vision controller then verification is confirmed. Incorrect date reading will execute fault systems to prevent continued production.
Label Presence and Application Quality Detection
Packaged containers travelling through label systems can suffer from labelling irregularities that affect the final quality of the product. Using a vision sensor it is possible to identify containers with labels that are missing or not correctly applied to the package. The vision sensor can detect incidents of missing labels, crooked or skewed labels or almost any defect which is a visual variation from the accepted quality standard. In addition the vision system can detect if the incorrect label roll has been loaded into the labeller, unique label graphics and even barcodes can be checked to ensure they are the correct match for the product being packed. Where front and back labels are applied the vision system using two cameras can ensure that both labels are the correct matched pair for the product.
Cap Application Quality and Fill Height Inspection
The inspection process can include other elements including cap checking, missing or cocked cap and also product fill heights where transparent packaging is used. In many cases multiple inspection processes can be carried out simultaneously. Therefore it is possible to check for cap, label date code and fill height all in one process.