| 摘要 |
PROBLEM TO BE SOLVED: To provide a reference-position detecting apparatus, for the adjustment of an optical axis, by which a cut line can be specified with good accuracy without being influenced by the flicker or the like of a reflecting plate. SOLUTION: In this reference-position detecting apparatus, an expansion processing operation is performed by an image expansion part 3, to gray-level-image data on a projection pattern, and every image obtained by a shrinkage processing operation in an image shrinkage part 4 is difference-processed by a difference processing part 5. In an obtained difference image, the part of a cut line becomes bright. A horizontal component region which contains a horizontal line is extracted by an image division part 7. The maximum position of the integration of a density value obtained by projecting the horizontal line in the vertical-axis direction is decided as a horizontal line by a horizontal line decision part 8. An oblique-line decision part 9 turns the difference image by a prescribed angle, it makes an oblique line horizontal, it finds the maximum value of the integration of a density value obtained by projecting the oblique line in the vertical-axis direction, it turns the oblique line reversely, and it finds an oblique line. An optical-axis decision part 10 finds the point of intersection of both lines so as to be used as a reference position for the adjustment of an optical axis. |
