PATTERN INSPECTION DEVICE FOR PRINTED MATTER

• Main Authors: KIZU SHUJI, SATO TOSHIO
• Format: Patent
• Language: English
• Published: 30.04.1992
• Subjects: CALCULATING; CHECKING-DEVICES; COLORIMETRY; COMPUTING; COUNTING; HANDLING OF COINS OR OF PAPER CURRENCY OR SIMILAR VALUABLEPAPERS, e.g. TESTING, SORTING BY DENOMINATIONS, COUNTING,DISPENSING, CHANGING OR DEPOSITING; IMAGE DATA PROCESSING OR GENERATION, IN GENERAL; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; LINING MACHINES; MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT,POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRA-RED,VISIBLE OR ULTRA-VIOLET LIGHT; MEASURING; PERFORMING OPERATIONS; PHYSICS; PRINTING; PRINTING MACHINES OR PRESSES; RADIATION PYROMETRY; STAMPS; TESTING; TRANSPORTING; TYPEWRITERS

PURPOSE:To perform inspection in details for pattern on a printed matter for which multi-color printing is done on both surfaces by a method wherein color component information on front and rear both surfaces of a printed matter is simultaneously read, and pattern comparison is performed by converting the information into a signal which is suitable for the sense of human beings, and being good or not of the pattern is comprehensively inspected. CONSTITUTION:For a printed matter P, color component information on the surface is read by a color line sensor 6, and is converted into color component signals for R, G and B. The color component signals for R, G and B which are output from the color line sensor 6 are converted into digital signals by A/D converters 11-13, and then, are normalized by correction circuits 14-16 in order to obtain uniform conversion information, and sent to a color conversion circuit 17. The color conversion circuit 17 converts the color component signals for R, G and B which are input into signals for equal sensibility space L*, a*, b*. The signals which are output from the color conversion circuit 17 L*, a*, b* are written in a first data collection circuit 18 regarding all picture elements of the pattern of the printed matter P, and transferred to a picture image analysis unit 5. The picture image analysis unit 5 collects and analyzes data of several sheets of the printed matter P.