IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD

• Main Authors: KITAJIMA KATSUYUKI, OTA NAOKI
• Format: Patent
• Language: English; Japanese
• Published: 28.12.2016
• Subjects: CINEMATOGRAPHY; ELECTROGRAPHY; ELECTROPHOTOGRAPHY; HOLOGRAPHY; MAGNETOGRAPHY; PHOTOGRAPHY; PHYSICS

PROBLEM TO BE SOLVED: To provide an image forming apparatus that can suppress filming on a photoreceptor without increasing a content of a release agent in a toner.SOLUTION: The image forming apparatus includes an electrophotographic photoreceptor having a surface protective layer, developing means accommodating a developer comprising a toner, and cleaning means having a cleaning blade. The toner comprises a binder resin, a colorant and a release agent and has a sea-island structure having a sea part comprising the binder resin and the colorant and an island part comprising the release agent. In an uneven distribution degree B of the island part comprising the release agent, represented by formula (1): uneven distribution degree B=2d/D (where D represents a circle-equivalent diameter (μm) of the toner in cross-sectional observation of the toner and d represents a distance (μm) from the gravity center of the toner to the gravity center of an island part comprising the release agent in the cross-sectional observation of the toner.) The mode of a distribution of the uneven distribution degree B is 0.75 or more and 1.00 or less and the skewness of the distribution of the uneven distribution degree B is -1.10 or more and -0.50 or less.SELECTED DRAWING: None 【課題】トナー中の離型剤の含有量を増やさずとも、感光体フィルミングを抑制しうる画像形成装置を提供すること。【解決手段】表面保護層を備えた電子写真感光体と、トナーを含む現像剤を収容する現像手段と、クリーニングブレードを有するクリーニング手段と、を備え、前記トナーが、結着樹脂、着色剤、及び離型剤を含み、前記結着樹脂、及び着色剤を含む海部と、前記離型剤を含む島部と、を持つ海島構造を有し、式（１）で示される前記離型剤を含む島部の偏在度Ｂ（式（１）：偏在度Ｂ＝２ｄ／Ｄ（式（１）中、Ｄはトナーの断面観察におけるトナーの円相当径（μｍ）を示す。ｄは、トナーの断面観察におけるトナーの重心から離型剤を含む島部の重心までの距離（μｍ）を示す。）において、前記偏在度Ｂの分布の最頻値が０．７５以上１．００以下であり、前記偏在度Ｂの分布の歪度が−１．１０以上−０．５０以下である、画像形成装置。【選択図】なし