| 摘要 |
PURPOSE:To accurately detect a defect such as printing misregistration, etc., by manufacturing a multiple gradation area image of a surface to be inspected from image data to be output from a line sensor, and comparing it with density levels of corresponding parts of a mask image. CONSTITUTION:A sheetlike printed matter S to be continuously fed is irradiated from a light source 2, and an entire width of a surface of the matter S is imaged by a CCD line sensor 1. Line image data fed from the sensor 1 is converted to multiple gradation area image data by a processor 5. The data is transmitted to a personal computer, sequentially stored in memory means, and multiple gradation area image of an image to be inspected is formed. Then, the image is pattern-matched to a master image, corresponding parts of both the images are specified, density levels of the data of the corresponding parts are compared to detect a part in which a density level difference exceeds an allowable value. The detected part is automatically decided as a defective part or whether it is a defective part or not is finally decided further by another deciding process. |
