Image forming apparatus

An image forming apparatus comprising:

• an image forming unit forming a toner image generated based on an image data, onto a recording medium;
• a fixing unit fixing the toner image generated on the recording medium, onto the recording medium with a heat roller and a pressure roller;
• a thermopile array sensor being located at a point opposed to a central portion of the heat roller, including a plurality of thermopile elements arranged in a two-dimensional array pattern, and a temperature detection surface divided into a plurality of predetermined regions aligned in vertical and horizontal directions, the thermopile elements being configured to output a temperature detection signal corresponding to a temperature of the respective predetermined regions;
• reflectors including a first reflecting mirror located at a point opposed to a measurement point which is a part of the heat roller in the fixing unit and is a part outside of a viewing angle of the thermopile array sensor, and a second reflecting mirror located at a point shifted in the axial direction of the heat roller from the locational position of the first reflecting mirror and ahead of the temperature detection surface of the thermopile array sensor, each of the reflectors being configured to reflect, toward the axial direction of the heat roller with the first reflecting mirror, infrared light emitted from the measurement point so as to allow the reflected infrared light, with the second reflecting mirror, to be limitedly incident on the predetermined regions of the temperature detection surface;
• and
• a temperature detection unit that detects the temperature on the basis of the temperature detection signal outputted from each of the plurality of thermopile elements,
• wherein there are a plurality of the measurement points at different points in the axial direction of the heat roller, each of the measurement points respectively has one of the reflectors, and the predetermined regions on which each infrared light emitted from each of the measurement points are incident are respectively set to be different from each other at the every measurement points,
• the thermopile array sensor is arranged at a position where the infrared light emitted from the measurement point is to be incident on temperature detection regions other than the predetermined regions of the temperature detection surface, and the measurement point is a part of the heat roller within the viewing angle of the thermopile array sensor,
• the temperature detection unit detects the temperature of each of the measurement points respectively corresponding to the predetermined regions and the temperature detection regions on the basis of the temperature detection signal outputted from each of the thermopile elements arranged at the respective predetermined regions and the temperature detection regions,
• the thermopile array sensor and the plurality the reflectors are located inside the image forming apparatus, and
• the first reflecting mirror is at one longitudinal end of the heat roller, and the second reflecting mirror and the thermopile array sensor are at a center of the heat roller.