| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface state detection apparatus configured to increase sensor output without increasing an inrush current to a light-emitting unit or an amplification factor of an amplifier, while contributing to extending the service life and improving detection accuracy.SOLUTION: A surface state detection apparatus 70 includes: a reflective optical sensor 200 arranged opposite a portion of a fixing belt 61 supported by a heating roller 62; and detection information processing means 300. The reflective optical sensor 200 includes: a light-receiving system formed by at least two light-receiving units; and a light-receiving optical system for guiding a light flux reflected by an object to be detected to the light-receiving system. As for an area between arbitrary two adjacent light-receiving units among the light-receiving units, an output to be obtained when a light-receiving unit of a size corresponding to the area is arranged in the area is estimated from outputs in the arbitrary adjacent two light-receiving units. The estimated output is used for detecting the object to be detected. |
