Patent attributes
A web inspection system provides detection of web flaws along the machine direction and cross direction of a web. The detectable percent contrast between good web material and bad web material in one embodiment approaches noise level. The web inspection system utilizes a multiple of smart cameras connected to a host computer via an ethernet hub. Each smart camera includes a line scan camera for producing digital pixels, a means for lighting and pixel correction on a pixel by pixel basis, a web edge detector for monitoring the edges of a web, a multi-pipeline flaw detection pre-processor for detecting very small changes in the web material, a run length encoder for generating data regarding the location of each group of potential flaws in a cross direction, a 2D blob detector and analyzer for generating data regarding the location of block flaws along a machine direction, and an inspect/reject analysis for determining the actual flaw data from the potential flaw data. A low contrast web inspection system provides a balanced and distributed architecture that handles high defect rates, and that is easily integrated with an existing web manufacturing system.
