| 摘要 |
PROBLEM TO BE SOLVED: To fix an image with an appropriate size to a sheet according to the type of the sheet.SOLUTION: An image forming apparatus 1 includes: an image forming unit 20; a fixing unit 30 that heats a sheet P to fix an image to the sheet P; a light source unit 71a that irradiates the sheet P with light; a polarization filter 72 that passes light in a predetermined polarization direction, of the rays of reflection light from the sheet P; a light intensity detection unit 73 that detects the intensity of the light passed through the polarization filter 72; a sheet determination unit 82 that determines whether or not the sheet P extends during heating on the basis of a change in the detected intensity of the light (detection intensity) D; an extension direction specification unit 84 that specifies the extension direction of the sheet P on the basis of the change; an extension ratio calculation unit 86 that calculates an extension ratio on the basis of a ratio of a detection intensity (extension direction intensity) F when the polarization direction is the extension direction and an extension direction intensity (reference intensity) G when the sheet P is paper that does not extend during heating; and an image extension unit 87 that extends an image formed on the sheet P at the extension ratio in the extension direction. |
