Fixing device including detecting mechanism which detects infrared rays radiated from heating body and image forming apparatus including same

摘要

A fixing device includes a heating body, a pressuring body, a heat source and a detecting mechanism. The detecting mechanism is not in contact with the heating body and including an infrared detecting element which detects infrared rays radiated from an outer circumferential face of the heating body. A longitudinal direction of the heating body is a second direction which crosses a first direction as a conveying direction of a recording medium. A detected area is arranged on the outer circumferential face of the heating body so that the infrared rays radiated from the detected area is detected by the infrared detecting element. The detecting mechanism is arranged in a posture inclined to another posture facing the outer circumferential face of the heating body so that a width in the second direction of the detected area is wider than a width in the first direction of the detected area.

主权项

1. A fixing device comprising:
a heating body configured to be rotatable; a pressuring body configured to be rotatable and to come into pressure contact with the heating body so as to form a fixing nip; a heat source configured to heat the heating body; and a detecting mechanism configured to be not in contact with the heating body and including an infrared detecting element which detects infrared rays radiated from an outer circumferential face of the heating body, wherein a longitudinal direction of the heating body is a second direction which crosses a first direction as a conveying direction of a recording medium, and a detected area is arranged on the outer circumferential face of the heating body so that the infrared rays radiated from the detected area is detected by the infrared detecting element, and the detecting mechanism is arranged in a posture inclined to another posture facing the outer circumferential face of the heating body so that a width in the second direction of the detected area is wider than a width in the first direction of the detected area, further comprising a heat insulating member arranged between the heating body and the detecting mechanism, wherein the heat insulating member has an opening through which the infrared rays radiated from the outer circumferential face of the heating body passes, and a flow passage of cooling air is arranged between the detecting mechanism and the heat insulating member so that the flow passage is spaced away from the opening.