Image forming apparatus capable of suppressing maldistribution of an ion conductive agent on an intermediary transfer member

An image forming apparatus comprising:

• a plurality of image bearing members each configured to bear a toner image;
• an intermediary transfer member configured to feed the toner image, primary-transferred from each of said image bearing members, for secondary-transferring the toner image onto a recording material, said intermediary transfer member being a rotatable endless member having ion conductivity;
• a plurality of primary transfer members provided corresponding to said image bearing members, respectively, and each configured to form a primary transfer portion where the toner image is primary-transferred from said corresponding image bearing member onto said intermediary transfer member, wherein each of said primary transfer members primary-transfers the toner image from said corresponding image bearing member onto said intermediary transfer member under application of a first transfer voltage thereto;
• a first applying portion configured to apply the first transfer voltage to said primary transfer members;
• a secondary transfer member configured to form a secondary transfer portion where the toner image is secondary-transferred from said intermediary transfer member onto the recording material, wherein said secondary transfer member secondary-transfers the toner image from said intermediary transfer member onto the recording material under application of a second transfer voltage thereto;
• a second applying portion configured to apply the second transfer voltage to said secondary transfer member;
• and
• a controller configured to carry out control of said first applying portion,
• wherein on the basis of image information, image formation is carried out in an operation in a first mode and in an operation in a second mode in which a number of said image bearing members on which the toner image is formed is less than that in the first mode and in which a number of said primary transfer members to which the first transfer voltage is applied is less than that in the first mode,
• wherein on the basis of the image information, said controller controls the first transfer voltage applied to said primary transfer members during the primary transfer of an image to be formed on a single recording material so as to be different between a first voltage when a first region, in which a coverage indicating a ratio occupied by an image region per predetermined area is a first coverage, passes through the primary transfer portions and a second voltage when a second region, in which the coverage is a second coverage larger than the first coverage, passes through the primary transfer portions, and
• wherein said controller controls a change amount of the first voltage with respect to the second voltage so as to be different between the first mode and the second mode.

An image forming apparatus comprising:

• a plurality of image bearing members each configured to bear a toner image;
• an intermediary transfer member configured to feed the toner image, primary-transferred from each of said image bearing members, for secondary-transferring the toner image onto a recording material, said intermediary transfer member being a rotatable endless member having ion conductivity;
• a plurality of primary transfer members provided corresponding to said image bearing members, respectively, and each configured to form a primary transfer portion where the toner image is primary-transferred from said corresponding image bearing member onto said intermediary transfer member, wherein each of said primary transfer members primary-transfers the toner image from said corresponding image bearing member onto said intermediary transfer member under application of a first transfer voltage thereto;
• a first applying portion configured to apply the first transfer voltage to said primary transfer members;
• a secondary transfer member configured to form a secondary transfer portion where the toner image is secondary-transferred from said intermediary transfer member onto the recording material, wherein said secondary transfer member secondary-transfers the toner image from said intermediary transfer member onto the recording material under application of a second transfer voltage thereto;
• a second applying portion configured to apply the second transfer voltage to said secondary transfer member;
• and
• a controller configured to carry out control of said second applying portion,
• wherein said controller controls the second transfer voltage applied to said secondary transfer member when a single recording material passes through the secondary transfer portion so as to be different between a first voltage when a marginal portion of the recording material onto which the toner image is not transferred passes through the secondary transfer portion and a second voltage when a region of the recording material onto which the toner image is transferred passes through the secondary transfer portion, and
• wherein said controller carries out control so that an absolute value of the first voltage is greater than an absolute value of the second voltage.