(From VDMA--The German Engineering Federation)
Two vision systems are being used to supervise the printing of bingo lottery tickets in Sweden. The lottery tickets are printed at Idrottens Digital Print AB (IDP) in Mölnlycke.
A ticket has 225 numbers and an individual number that makes every ticket unique. All the numbers, including barcodes, are printed with two inkjet printers. The printing is done with variable data and at a speed of 25 lottery tickets per second, or 300 meters per minute. Four JAI cameras, model M10, are used to inspect the printing--two for each printer. Together the two cameras read about 1000 characters per second. One camera examines the lottery ticket itself, and the other one inspects the numbers and barcodes.
The two camera systems work independently. However, the two systems are synchronized, which enables them to check that the right digits are printed on each ticket. Only one combination of numbers on each ticket corresponds to the five-digit lottery number. The lottery numbers form a complicated graphical object, which is recognized and transformed into characters by special software using optical character recognition.
The system software is PrintVision from Soft Design RTS AB (Gothenburg), with a pattern-recognition module, Minos, from Stemmer Imaging's software library Common Vision Blox. The system checks that the bingo numbers are printed in each square, the bingo numbers for each lottery ticket correspond to the individual lottery number, there are no ink stains, the barcode corresponds to serial- and lottery number, the lottery number is increased with one for each ticket, and the serial number does not change during printing. Misprints are immediately detected and shown as a still image on the PC monitor. A red light informs the operator that an error has occurred and is active until the operator fixes the error.
In addition, the system creates a log for each fault that occurs. The vision system also includes four PCI frame grabbers from DALSA.