| 摘要 |
PROBLEM TO BE SOLVED: To solve the following problem; in the case the size of a sheet material is not confirmed, image masking is not performed, or an image mask is set in accordance with the sheet material of maximum size, then, in the case of continuously making a narrow sheet material pass through a transfer roller and the like, the transfer roller and the like are soiled in a printer device and the outputted image is also soiled in the case of using a wide sheet material. SOLUTION: The image forming device is provided with a heater whose length is equal to or exceeding the width of the passing sheet material, a 1st temperature detecting means for detecting the temperature of the heater and a 2nd temperature detecting means for detecting the temperature of the heater, and in the case the narrow sheet material passes, the image mask is changed based on the detection temperature difference between the 1st temperature detecting means and the 2nd temperature detecting means. |
