Image forming apparatus

An image forming apparatus, comprising:

• an image bearing member configured to bear a non-fixed toner image;
• a transfer portion configured to form a transfer nip together with the image bearing member and to transfer the non-fixed toner image borne on the image bearing member to a sheet at the transfer nip;
• a fixing portion comprising a first rotary member, a second rotary member forming a fixing nip together with the first rotary member and a heating portion configured to heat the first rotary member, the fixing portion being configured to fix the non-fixed toner image which has been transferred onto the sheet to the sheet as a fixed toner image by heat and pressure at the fixing nip;
• a re-conveyance portion configured to convey the sheet that has passed through the fixing portion toward the fixing portion again;
• a control portion configured to execute a nip image forming process of forming a nip image, on the sheet, corresponding to a shape of the fixing nip by stopping a conveyance of the sheet being conveyed by the fixing portion in a state in which the fixed toner image formed on the sheet is nipped by the fixing nip;
• and
• a reading unit configured to read the nip image,
• wherein the control portion stops the conveyance of the sheet being conveyed by the fixing nip and the transfer nip in a state in which the sheet is not in contact with a part of the first rotary member other than the fixing nip in the nip image forming process.

An image forming apparatus, comprising:

• an image forming unit comprising an image bearing member configured to bear a non-fixed toner image, a transfer portion configured to form a transfer nip together with the image bearing member and to transfer the non-fixed toner image borne onto the image bearing member to a sheet at the transfer nip, and a storage portion configured to store toners of a plurality of colors;
• a fixing portion comprising a first rotary member, a second rotary member forming a fixing nip together with the first rotary member, and a heating portion configured to heat the first rotary member, the fixing portion being configured to fix the non-fixed toner image which has been transferred onto the sheet to the sheet as a fixed toner image by heat and pressure at the fixing nip;
• and
• a control portion configured to execute an inspection mode of preparing a measurement sheet used to measure a shape of the fixing nip,
• wherein the control portion executes, in the inspection mode, an inspection image forming process of transferring and fixing an inspection image formed by laminating a plurality of toner layers onto the sheet, and a nip image forming process of forming a nip image corresponding to the shape of the fixing nip by stopping a conveyance of the sheet being conveyed by the fixing portion in a state in which the inspection image is nipped by the fixing nip,
• wherein the plurality of toner layers transferred onto the sheet by the transfer portion includes a first toner layer which is an uppermost layer formed by a first color toner, and a second toner layer formed adjacent to the first toner layer and formed by a second color toner different from the first color, and
• wherein the first color is a chromatic color.