IMAGE FORMING APPARATUS

To solve the problem in which: since in a situation with high image density and a large amount of toner, a fixing device F is deprived of heat in a larger quantity, even when an image forming apparatus identifies an image with a large amount of toner and changes a fixing air condition during fixing processing for a page with high image density, the quantity of heat becomes insufficient in the subsequent pages in execution of continuous printing regardless of their image density, which leads to the occurrence of a defective fixing.SOLUTION: An image forming apparatus detects information on the density on a recording material, and changes control of a fixing device F according to the image density on the recording material to optimize fixability. Within the number of pages required until the fixing device recovers from a reduction in its temperature occurring when a page with high image density is fixed, the image forming apparatus performs correction to increase the fixing temperature conditioning temperature for the page with high image density, and performs correction to increase the fixing temperature conditioning temperature for pages subsequent to the page in continuous printing regardless of information on the density of the preceding pages, and thereby can prevent both curls and the occurrence of a defective fixing in the subsequent pages.SELECTED DRAWING: Figure 1 【課題】画像濃度が高くトナー量が多い場合には定着装置Ｆの熱量もより多く奪われるため、たとえトナー量の多い画像を識別し、そのページの定着処理時に定着温調を変更したとしても、連続プリントされる場合の後続ページにおいてその画像濃度に関わらず熱量が不足してしまい、定着不良が発生してしまう。【解決手段】記録材上の濃度情報を検知し、記録材上の画像濃度に応じて定着装置Ｆの制御を変更し、定着性を最適化する画像形成装置において、画像濃度の高いページが定着された際に生じる定着部材の温度低下が復帰するまでの枚数内において、画像濃度の高いページの定着温調温度を上げる補正を行うとともに、その連続プリント後続ページも先行ページの濃度情報に関わらず定着温調温度を上げる補正することで、後続ページにける定着不良発生をカールと両立して抑制することが出来る。【選択図】図１