| 摘要 |
PROBLEM TO BE SOLVED: To form images without a printing position deviation even when an optical system skews, or a photoreceptor drum or an intermediate transfer body mechanically vibrates in an electrophotographic apparatus having a plurality of light sources. SOLUTION: In a position calculation in Fig. (a), when a plotting image is scanned over a correction segment in a horizontal scanning direction, a quantization data (j) corresponding to a plotting line (i) without corrections resulting from detecting the plotting image is recognized on a bit mat matrix. Moreover, a reference line (h) is stored as an original plotting data (k) quantized on the bit mat matrix as represented by Fig. (b). A quantity of bits of the quantization data (j) at an earlier measured position displaced from the original plotting data (k) is calculated. A bit correction of shifting the quantization data (j) in a counter direction by the quantity of bits displaced from the original plotting data (k) is carried out, whereby a plotting data (m) after the correction is generated as corrected plotting data of Fig. (c). Furthermore, printing can be corrected in a vertical scanning direction by executing plotting on the basis of the plotting data m after the correction as indicated by Fig. (d). |
