| 摘要 |
PURPOSE:To form a reference toner image which has a proper optical reflection density corresponding to an electrophotographic process condition which is the control object, by averaging always the optical reflection density of the reference toner image as the whole. CONSTITUTION:A reference pattern generating circuit 11 generates a pattern formed by repeating a fundamental pattern where the number of lines in the subscanning direction is a value, for example, 7 which has not the same divisor as the number of specular surfaces of a polygonal mirror 3, namely, 8. Consequently, though the same fundamental pattern is formed with the same signal, the width in the subscanning direction of a black part of the formed fundamental pattern is different by the specular surface position then. Since one fundamental pattern consists of 7 lines, the black part is started with the line scanned by the specular surface of surface number 2 in the fundamental pattern following the fundamental pattern where the black part is started with the line scanned by the specular surface of surface number 3 as shown in a figure A. The black part is started with the line scanned by the specular surface of surface number 1 with respect to the following fundamental pattern, and the black part appears in the 5th line from the line in the fundamental pattern of the figure A with respect to the fundamental pattern shown in a figure B, and the 9th fundamental pattern is returned to that in the figure A. |
