| 摘要 |
PURPOSE:To obtain always the image due to each color toner which is safe with respect to fixability, by changing the rotation start time, when a fixing roll is rotated before fixing, in accordance with the color of a used developer. CONSTITUTION:The first surface temperature set values T1BK.T1BL.T1R of a fixing roll 14 are determined suitably in accordance with the fixability of individual toners. With respect to the surface temperature of the fixing roll in case of a black toner, it is raised along a line (a) after a power source is turned on, and it is raised along a line (b) after it reached the surface temperature set value T1BK for the black toner, and it reaches the second surface temperature set value T2 after tBK-number of seconds, and wait-up is completed. In case of a blue toner, the surface temperature of the fixing roll is raised along the line (a) after the power source is turned on, and it is raised along a line (c) after it reaches the first surface temperature set value T1BL for the blue toner. Lines (c) and (b) have the same inclination. In case of the blue toner, the line of the rise of surface temperature is switched to the line (c), and this switching is earlier than that of the black toner (becaue of T1BK>>T1BL), and the time spent in wait-up is longer, and wait-up is completed after tBL- number of seconds. |
