| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming device capable of diagnosing conveyance failure in a feed section. <P>SOLUTION: A displacement information acquisition section 80 is provided in a feed tray 51 so as to face a printing sheet to detect passage of the rear edge of the printing sheet in the carrying direction and a moving speed thereof. In the displacement information acquisition section 80, the printing sheet is irradiated with illumination light L1, and scattered and reflected components L13 thereof are received by a displacement detecting sensor 86. The displacement detecting sensor 86 observes structural features appearing on the surface of the printing sheet in a feeding process for detection of the passage of the rear edge of the printing sheet. A control circuit 102 corrects a first sensor passage time T65, which is obtained by using a first sensor 65 with an ON-period of solenoid 61 as a base point, by a sheet end passage time T80, which is obtained by using the displacement information acquisition section 80, so that a first sensor passage time T6580 is obtained. The control circuit 102 diagnoses presence of the failure, failure states and failure detail based on a degree of a deviation of the first sensor passage time T6580 from a normal range. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
