Image forming apparatus

摘要

In an image forming apparatus, a sensor section includes a sheet path through which the sheet passes in a sheet feeding direction. In the sensor section, a light source unit emits light to an irradiation area set in the sheet path. Here, the light is elongated in a main-scanning direction and has quantities of light varying according to positions in the main-scanning direction and according to positions in a height direction perpendicular to a sheet feed surface. In addition, in the sensor section, a light-receiving section receives light diffused in a predetermined diffusing direction among the light emitted from the light source and then irradiated to the sheet passing in the sheet path and outputs information representing quantities of the received light. In the image forming apparatus, a control section extracts a parameter from the information and derives an amount of curl of the sheet.

主权项

1. An image forming apparatus comprising:
an image forming section configured to form a toner image on a sheet; a fixing section configured to fix the toner image formed by the image forming section on the sheet and to feed the sheet out therefrom; and a sensor section configured to read the toner image on the sheet fed from the fixing section; wherein the sensor section includes: a sheet path configured to lead the sheet fed from the fixing section to pass in a predetermined sheet feeding direction; a light source unit configured to emit light toward an irradiation area preliminarily set in the sheet path, the light being elongated in a main-scanning direction different from the sheet feeding direction and having quantities of light varying according to positions in the main-scanning direction and according to positions in a height direction perpendicular to a sheet feed surface; and a light-receiving section configured to receive light diffused in a predetermined diffusing direction different from the sheet feeding direction and the main-scanning direction among the light emitted from the light source and then irradiated to the sheet passing in the sheet path, and to output information representing quantities of the received light; and wherein the image forming apparatus further comprises: a control section configured to extract a predetermined parameter from the information output from the light-receiving section and to derive an amount of curl of the sheet passing in the sheet path.