| 摘要 |
PROBLEM TO BE SOLVED: To increase or decrease the number of formed patches for correcting reference concentration of toner by which printing is performed between transfer materials in accordance with a distance between the transfer materials which are conveyed by a conveying belt. SOLUTION: A CPU 2 generates a permission signal of patch generation which permits the generation of the patches on a photoreceptor drum 30. The permission signal is turned on at the time (Time T5) of completing the generation of normal print picture 61c on the photoreceptor drum 30 and is turned off at the time (Time T6) which is Td2 hours before the time (Time T7) of generating the subsequent normal print picture 61d on the photoreceptor drum 30. All generable patches 60 are generated during the time that the permission signal of patch generation is turned on (Td1 hours). Thereby, even when a space between sheets of paper to be conveyed is varied, the number of formed patches is increased or decreased in accordance with the space between sheets of paper and, therefore, even under the execution of normal printing where the space between sheets of paper is varied, the formation of the patch is mage possible. |
