Image forming apparatus including pressers configured to press a receptor to image bearers downward in the vertical direction

An image forming apparatus, comprising:

• plural image bearers configured to bear toner images comprising a black toner image, which are developed with a two-component developer comprising a carrier and a toner including a binder resin and an additive;
• a receptor configured to receive the toner images;
• plural pressers each configured to press the receptor to each of the plural image bearers at a predetermined pressure,
• wherein the additive has a burial rate X indicated by the following formula not less than 40%:
• X=(A−B)/A×100
• wherein A represents a BET specific surface area (cm2/g) of the toner;
• and B represents a BET specific surface area (cm2/g) of the toner after the additive is buried,
• wherein one of the pressers pressing the receptor to the image bearer bearing the black toner image presses the receptor thereto at a pressure lower than those of the other pressers,
• wherein each of the pressers includes a pressing member contacting the receptor, configured to press the receptor to each of the image bearers, and
• wherein the predetermined pressure of each presser is generated by a spring strength of each presser,
• wherein the spring strength of the plural pressers is different between two or more pressers, and
• wherein the predetermined pressure of the presser pressing the receptor to the image bearer bearing the black toner image is at least 50% of the predetermined pressure of another one of the pressers.

An image forming apparatus, comprising:

• plural image bearers configured to bear toner images comprising a black toner image, which are developed with a two-component developer comprising a carrier and a toner including a binder resin and an additive;
• a receptor configured to receive the toner images;
• plural pressers each configured to press the receptor to each of the plural image bearers at a predetermined pressure,
• wherein the additive has a burial rate X indicated by the following formula not less than 40%:
• X=(A−B)/A×100
• wherein A represents a BET specific surface area (cm2/g) of the toner;
• and B represents a BET specific surface area (cm2/g) of the toner after the additive is buried,
• wherein one of the pressers pressing the receptor to the image bearer bearing the black toner image presses the receptor thereto at a pressure lower than those of the other pressers,
• wherein each of the pressers includes a pressing member contacting the receptor, configured to press the receptor to each of the image bearers, and
• wherein the predetermined pressure of each presser is generated by a spring strength of each presser,
• wherein the spring strength of the plural pressers is different between two or more pressers, and
• wherein the predetermined pressure of the presser pressing the receptor to the image bearer bearing the black toner image is no more than 70% of the predetermined pressure of another one of the pressers.