| 摘要 |
<P>PROBLEM TO BE SOLVED: To determine the lifetime of a transfer belt from a measured value obtained, by measuring the speed deviation of the transfer belt. <P>SOLUTION: In a color image forming method, in which a color image is formed by respectively superposing a plurality of color images on the transfer belt by a plurality of photoreceptor drums on which different color images are formed, and is transferred to a recording medium, a toner mark pattern is plotted on the transfer belt (step S102), the distance between the toner mark patterns is measured (step S103), and the measured value is compared with the predetermined set value (step S104). When an error, equal to or above a fixed value has been generated, it is decided as being at the duration of the life of the transfer belt (step S105). <P>COPYRIGHT: (C)2007,JPO&INPIT |
