Fixing apparatus and image forming apparatus

An image forming apparatus comprising:

• an image forming unit configured to form a toner image onto a sheet;
• and
• a fixing apparatus configured to fix the toner image formed by the image forming unit onto the sheet, the fixing apparatus including:
• a first rotary member which is formed to be endless;
• a heating element disposed inside of the first rotary member;
• a second rotary member in contact with an outer circumferential surface of the first rotary member and forming a nip portion which fixes a toner image onto a sheet together with the first rotary member;
• a nip member provided slidably with an inner circumferential surface of the first rotary member so as to nip the first rotary member together with the second rotary member and configured to heat the nip portion by receiving radiant heat from the heating element;
• a reflection member reflecting the radiant heat from the heating element toward the nip member;
• and
• a support member supporting the nip member through the reflection member,
• wherein the support member is configured to transition between a pressurized state and a non-pressurized state, the pressurized state being a state in which a first end position and a second end position different from the first end position in a rotation axial direction of the support member are pressurized in a pressurization direction toward the second rotary member, the non-pressurized state being in which the pressurized state of the support member is released,
• wherein the support member comprises a contact surface in contact with the reflection member in the pressurized state,
• wherein the contact surface includes a center position between the first and second end positions in the rotation axial direction, and
• wherein the contact surface takes a posture such that a first difference between a distance of the center position to the second rotary member and a distance of the first and second end positions to the second rotary member in a case where the support member is in the non-pressurized state is larger than a second difference between the distance of the center position to the second rotary member and the distance of the first and the second end positions to the second rotary member in a case where the support member is in the pressurized state.