| 摘要 |
A control portion of a sheet detection device causes a light emitter to emit light with a predetermined amount of light emission, to determine whether or not a first reference sheet is in a detection area. When the first reference sheet is not in the area, a sheet detection sensor is moved upward by a predetermined movement pitch. When the first reference sheet is in the area, the present detection distance between the sheet detection sensor and the first reference sheet is stored. The control portion performs the same process for the second reference sheet. When both of the detection distances are correct, the control portion determines that an output from the sheet detection sensor is correct, and sets the present amount of light emission as an amount of light emission for a document detection process. When both of the detection distances are not correct, the output is determined as being incorrect, and an amount of light emission from the light emitter is increased by one step. |
