| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To disclose such technology that can suppress influences by variation in the reflectance of a carrying body in determining contamination of an optical sensor. <P>SOLUTION: When a printer 1 detects that a conveyance belt 16 is out of a reference position and away from a registration sensor 17, the printer imparts a light emission control value to the registration sensor 17 to allow the sensor to emit light with luminous energy in accordance with the light emission control value, and acquires luminous energy of light received by an optical sensor. If at least one of the imparted light emission control value or the acquired luminous energy of received light is out of a specified range, the printer determines that the registration sensor 17 is contaminated. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
