IMAGE FORMING APPARATUS, AND PROCESS CARTRIDGE

• Main Authors: KOIDE TAKASHI, KITAJIMA KATSUYUKI, TAKAHASHI SHOTARO, KURIBAYASHI MASATAKA, MOROOKA YASUHISA, ICHIJO NAGATO
• Format: Patent
• Language: English; Japanese
• Published: 02.02.2015
• Subjects: CINEMATOGRAPHY; ELECTROGRAPHY; ELECTROPHOTOGRAPHY; HOLOGRAPHY; MAGNETOGRAPHY; PHOTOGRAPHY; PHYSICS

PROBLEM TO BE SOLVED: To provide an image forming apparatus that suppresses occurrence of a change in density of images due to passing of silica particles through a cleaning blade under a low-temperature and low-humidity environment, and an increase in a rotational load of an image carrier under a high-temperature and high-humidity environment.SOLUTION: An image forming apparatus includes: an image carrier; developing means for accommodating an electrostatic charge image developer including a toner containing an external additive containing first silica particles having a number average particle diameter of 100 nm or more and 180 nm or less and a shape factor SF2 of 130 or more and 180 or less and second silica particles having a number average particle diameter of 100 nm or more and 180 nm or less and a shape factor SF2 of 100 or more and 125 or less, and developing electrostatic charge images formed on the surface of the image carrier as toner images with the electrostatic charge image developer; cleaning means including a cleaning blade cleaning the surface of the image carrier; and lubricant supply means for supplying a lubricant to the surface of the image carrier. 【課題】低温低湿環境下でのシリカ粒子のクリーニングブレードからのすり抜けに起因する画像の濃度変化が生じる現象及び高温高湿環境下での像保持体の回転負荷の上昇を抑制する画像形成装の提供【解決手段】像保持体と、個数平均粒径が１００ｎｍ以上１８０ｎｍ以下であり且つ形状係数ＳＦ２が１３０以上１８０以下である第１シリカ粒子、及び個数平均粒径が１００ｎｍ以上１８０ｎｍ以下であり且つ形状係数ＳＦ２が１００以上１２５以下である第２シリカ粒子を含む外添剤を有するトナーを含む静電荷像現像剤を収容し、静電荷像現像剤により、像保持体の表面に形成された静電荷像をトナー画像として現像する現像手段と、像保持体の表面をクリーニングするクリーニングブレードを有するクリーニング手段と、像保持体の表面に潤滑剤を供給する潤滑剤供給手段と、を備える画像形成装置である。【選択図】図１