Patent ID: 8737898

Claim:
A fixing device for thermally fixing a developing agent image to a sheet, the fixing device comprising: a tubular flexible member having an inner peripheral surface defining an internal space; a heater disposed in the internal space and configured to generate a radiant heat; a nip member disposed in the internal space, the inner peripheral surface being in sliding contact with the nip member; a reflection plate configured to reflect the radiant heat from the heater toward the nip member, the reflection plate having an outer profile; a backup member configured to provide a nip region in cooperation with the nip member for nipping the flexible member between the backup member and the nip member; a stay covering the reflection plate and supporting the nip member, the stay having a profile in conformance with the outer profile of the reflection plate; and, a temperature sensor disposed in the internal space, wherein the stay comprises a supporting wall having: a supporting surface configured to support the nip member; and a notch that is recessed from the supporting surface away from the nip member and is open toward the nip member, and, wherein the temperature sensor has at least a portion disposed within the notch and is arranged to oppose the nip member to detect a temperature of the nip member.