| 摘要 |
PURPOSE:To copy even an original having an ununiform density to transfer paper with a satisfactory image density by providing plural detecting means in a direction other than the scanning direction and adjusting the exposure by control means based on the detection signal having a maximum difference between upper and lower limits out of plural detection signals obtained from detecting means. CONSTITUTION:Detecting means 1a to 1c detect reflected light from the original at the time of scanning the original in a certain direction and output detection signals of the original density to control means 5, 9, and 10. Since detecting means 1a to 1c are provided in a direction other than the scanning direction, the overall density of the original is detected two-dimensionally. control means 5, 9, and 10 adjust the exposure based on the detection signal having a maximum difference between upper and lower limits out of detection signals. Consequently, an optimum exposure is set though the original density is partially different in the direction perpendicular to the scanning direction. Thus, the original is always copied with a satisfactory image density though the original has the variation in density. |
