| 摘要 |
An image forming apparatus includes a generation tendency determining section to determine, before execution of a job, whether or not this job is a large-amount generation tendency job that is likely to generate a large amount of ultrafine particles. When the current job is determined to be the large-amount generation tendency job and a toner adhesion status value is equal to or higher than a first predetermined threshold representing an amount of toner adhering to a surface of a fixing member, cleaning of the fixing unit is performed before execution of the job. On the other hand, when the current job is determined to be a small-amount generation tendency job or the toner adhesion status value is less than the predetermined first threshold, the job is executed without cleaning the fixing unit. |
| 主权项 |
1. An image forming apparatus comprising:
an image forming unit; a fixing unit configured to perform a fixing process in which a sheet having a surface bearing unfixed toner is passed through a fixing nip formed by a pair of fixing members placed in pressure contact with each other and heated to fix a toner image on the sheet; a cleaning section to remove toner from a surface of one of the fixing members, the one fixing member being located on a side facing the unfixed toner bearing surface of the sheet passing between the fixing members; a toner adhesion status value outputting section to output a toner adhesion status value representing an amount of toner adhering to the surface of the one fixing member; a generation tendency determining section to determine, before execution of a job, whether the job is a large-amount generation tendency job having a tendency to generate a large amount of ultrafine particles or a small-amount generation tendency job with a tendency to generate a small amount of ultrafine particles; and an apparatus control unit to control each part of the apparatus to execute the job, wherein the toner adhesion status value outputting section outputs a higher toner adhesion status value when the amount of toner adhering to the surface of the one fixing member is large than when the toner adhering amount is small, wherein when a current job is determined to be the large-amount generation tendency job and the toner adhesion status value before start of execution of the current job is equal to or higher than a first predetermined threshold, the apparatus control unit starts execution of the current job after performing a pre-job cleaning operation by the cleaning section, and when the current job is determined to be the small-amount generation tendency job or the toner adhesion status value before start of execution of the current job is less than the predetermined first threshold, the apparatus control unit starts execution of the current job without performing the pre-job cleaning operation by the cleaning section. |
