Recording medium transport mechanism, fixing device and image forming apparatus

A fixing device comprising:

• a fixing unit in which a recording medium onto which an unfixed image is transferred is nipped and transported and the unfixed image is fixed on the recording medium;
• a transporting device that is provided at a downstream side of the fixing unit in a direction in which the recording medium is transported, and that transports the recording medium by a drive roller and a facing roller that is disposed to face the drive roller;
• an urging member that urges the facing roller toward the drive roller;
• and
• a restricting portion that allows movement of the facing roller away from the drive roller against urging force of the urging member when the recording medium having thickness smaller than a predetermined thickness is transported in a region in which the drive roller and the facing roller face each other, and restricts an allowable amount of movement of the facing roller away from the drive roller when the recording medium having thickness equal to or larger than the predetermined thickness is transported in the region in which the drive roller and the facing roller face each other compared to an allowable amount of movement of the facing roller away from the drive roller when the recording medium having thickness smaller than the predetermined thickness is transported.

An image forming apparatus comprising:

• an accommodating unit in which a recording medium is accommodated;
• a transfer unit in which an unfixed image is transferred onto the recording medium that is fed from the accommodating unit;
• the fixing device including:
• a fixing unit in which a recording medium onto which an unfixed image is transferred is nipped and transported and the unfixed image is fixed on the recording medium;
• a transporting device that is provided at a downstream side of the fixing unit in a direction in which the recording medium is transported, and that transports the recording medium by a drive roller and a facing roller that is disposed to face the drive roller;
• an urging member that urges the facing roller toward the drive roller;
• and
• a restricting portion that allows movement of the facing roller away from the drive roller against urging force of the urging member when the recording medium having thickness smaller than a predetermined thickness is transported in a region in which the drive roller and the facing roller face each other, and restricts an allowable amount of movement of the facing roller away from the drive roller when the recording medium having thickness equal to or larger than the predetermined thickness is transported in the region in which the drive roller and the facing roller face each other compared to an allowable amount of movement of the facing roller away from the drive roller when the recording medium having thickness smaller than the predetermined thickness is transported,
• that fixes the unfixed image transferred by the transfer unit;
• and
• a discharge unit to which the recording medium on which the image is fixed by the fixing device is discharged.