Pressure device, image forming apparatus, and method of controlling pressure device

An image forming apparatus configured to form an image on a sheet medium, the image forming apparatus comprising:

• a transfer unit configured to transfer an image bearer formed on a surface of an intermediate transfer belt onto the sheet medium,
• the transfer unit comprising:
• a first pressing unit and a second pressing unit that are arranged to be able to approach to and separate from each other, and configured to send out the sheet medium while applying pressure to the sheet medium by at least one of the first pressing unit and the second pressing unit rotating in a state in which the first pressing unit and the second pressing unit hold the sheet medium;
• a driving unit configured to change a distance between the first pressing unit and the second pressing unit;
• a distance detection unit configured to detect the distance between the first pressing unit and the second pressing unit;
• a control unit configured to control the driving unit such that the distance between the first pressing unit and the second pressing unit becomes a set target value;
• and
• a target setting unit configured to set the target value, wherein the target setting unit
• sets the target value to a first distance that is larger than a thickness of the sheet medium when the sheet medium is not present between the first pressing unit and the second pressing unit, and
• sets the target value to a second distance for applying a target pressure to the sheet medium when the sheet medium and the image bearer are present between the first pressing unit and the second pressing unit.

A method of controlling a pressure device configured to apply pressure to a sheet medium on part of a surface of which an image bearer is formed,

• the pressure device including:
• a first pressing unit and a second pressing unit that are arranged to be able to approach to and separate from each other, and configured to send out the sheet medium while applying pressure to the sheet medium by at least one of the first pressing unit and the second pressing unit rotating in a state in which the first pressing unit and the second pressing unit hold the sheet medium;
• a driving unit configured to change a distance between the first pressing unit and the second pressing unit;
• a distance detection unit configured to detect the distance between the first pressing unit and the second pressing unit;
• a control unit configured to control the driving unit such that the distance between the first pressing unit and the second pressing unit becomes a set target value;
• and
• a target setting unit configured to set the target value, the method comprising:
• setting the target value to a first distance that is larger than a thickness of the sheet medium by the target setting unit when the sheet medium is not present between the first pressing unit and the second pressing unit, and
• setting the target value to a second distance for applying a target pressure to the sheet medium by the target setting unit when the sheet medium and the image bearer are present between the first pressing unit and the second pressing unit.