| 摘要 |
PURPOSE:To attain measurement at high speed with high accuracy by providing plural truncated chevron patterns and a read line so as not to move mechanically an original and an optical system of a read position of an optional picture element of a read device in the sub-scanning direction. CONSTITUTION:The truncated chevron patterns 91, 92 are formed by plural isosceles triangles whose equilateal side are drawn in parallel and the line width and the line interval of each side have a value close to an integral multiple of a pitch P of a read device CCD 3. The patterns 91, 92 are arranged on an original 1 in the read line direction (main scanning direction) so that both internal angles are theta respectively. Further, the distance between the patterns 91 and 92 is selected so that both the two patterns are read by the CCD 3 without fail. Thus, with respect to the patterns 91, 92 and the read line 8, the read position of an optional picture element of the CCD 3 in the sub-scanning direction is measured at high speed with high accuracy by using a lens 6 whose image is formed on picture elements 3-1-3-n of the CCD 3. |
