Pressure adjuster, fixing device, and image forming apparatus

A fixing device comprising:

• a fixing rotary body rotatable in a given direction of rotation;
• a heater disposed opposite and heating the fixing rotary body;
• a pressing rotary body pressed against the fixing rotary body to form a fixing nip therebetween;
• a pressurization assembly to press the pressing rotary body against the fixing rotary body;
• and
• a pressure adjuster contacting the pressurization assembly to change pressure between the pressing rotary body and the fixing rotary body,
• the pressure adjuster comprising:
• a cam rotatable in a given direction of rotation and having a top dead center on an outer circumferential surface thereof that is distanced farthest from a rotation axis of the cam;
• a driver connected to the cam to drive and rotate the cam;
• a cam rest contacting the cam and connected to the pressurization assembly;
• and
• a cam regulation assembly connected to the cam to regulate rotation of the cam at least when the top dead center of the cam passes a contact position where the cam contacts the cam rest.