Fixing device

A fixing device comprising:na tubular flexible fusing member having an inner peripheral surface defining an internal space;a nip plate extending in the internal space of the tubular flexible fusing member;a heater extending in the internal space and confronting the nip plate in a confronting direction, the heater comprising:na glass tube including a glass tube body and a tip portion protruding radially outward from the glass tube body,a heat source, anda gas sealed in the glass tube; anda reflection plate configured to reflect radiant heat from the heater,wherein the glass tube body defines an imaginary plane which is tangential to a closest generatrix of the glass tube closest to the reflection plate, the imaginary plane and the reflection plate defining a gap therebetween, the tip portion being outside of the gap,wherein the nip plate has a generally U-shape to provide a base portion extending along the heater and folded portions folded toward the heater, the base portion including a center portion and flat end portions, the center portion extending along the heater and disposed between the flat end portions, the center portion protruding in a direction away from the heater, andwherein the glass tube in its entirety overlaps with the center portion when projected in the confronting direction.