| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus suppressing difference in transfer efficiency in each toner to the minimum in a secondary transferring in an image forming apparatus and provided with a high image reproducing property with high transferring efficiency of total toner quantity. <P>SOLUTION: A primary transfer of a plurality of test pattern toner images consisting of two colors of toners is carried out on an intermediate transfer belt 7 and next a secondary transfer of the test pattern toner image is carried out by an intermediate transfer roller 11. Then, the total quantity of the two colors of toner remaining on the intermediate transfer belt 7 is detected by a transmitting type optical sensor of the optical sensor 50 and ratio of the remaining two color toners is detected by a reflecting type optical sensor of an optical sensor 50. Based on these detected results, transferring efficiency of the total quantity of the two colors of toners and transferring efficiency of each toner are calculated. Based on the transferring efficiency, a secondarty transfer voltage is selected with minimum difference in the transferring efficiency of each toner within the range where the transferring efficiency of the total quantity of the two colors of toner is greater than a specified value. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
