DEVELOPMENT DEVICE AND IMAGE FORMATION APPARATUS INCLUDING THE SAME

• Main Author: TAUCHI YASUHIRO
• Format: Patent
• Language: English; Japanese
• Published: 25.08.2016
• Subjects: CINEMATOGRAPHY; ELECTROGRAPHY; ELECTROPHOTOGRAPHY; HOLOGRAPHY; MAGNETOGRAPHY; PHOTOGRAPHY; PHYSICS

PROBLEM TO BE SOLVED: To provide a development device with high performance of removing accumulated toner from a layer thickness restriction member for restricting the layer thickness of a two-component developer on a surface of a developer carrier, and an image formation apparatus.SOLUTION: A development device 43 comprises: a sleeve part 460 which supplies toner to a developing roller 432 in a transition region E2; a magnet 445 which separates a developer from the sleeve part 460 in a downstream side region E3 in the normal rotation direction X1 with respect to the transition region E2; a blade 438 which is provided with a gap against the upstream side position L1 in the normal rotation direction X1 with respect to the transition region E2 and restricts the layer thickness of the developer carried by the sleeve part 460 rotating in the normal rotation direction X1; and a sheet member 666 which is provided with the gap against the second layer thickness restriction position L2 in the region E3 or between the region E3 and the position L1, restricts the layer thickness of the developer carried by the sleeve part 460 at the time of reverse rotation, and can be elastically deformed in accordance with the action of a pressing force equal to or greater than an allowable value in the reverse rotation direction X2.SELECTED DRAWING: Figure 2 【課題】現像剤担持体の表面における二成分現像剤の層厚を制限する層厚制限部材から堆積トナーを除去する性能の高い現像装置及び画像形成装置を提供すること。【解決手段】現像装置４３は、転移領域Ｅ２で現像ローラー４３２に供給するスリーブ部４６０と、転移領域Ｅ２よりも正回転方向Ｘ１における下流側の領域Ｅ３で現像剤をスリーブ部４６０から離間させる磁石４４５と、転移領域Ｅ２よりも正回転方向Ｘ１における上流側の位置Ｌ１に対し隙間を隔てて設けられ、正回転方向Ｘ１へ回転するスリーブ部４６０が担持する現像剤の層厚を制限するブレード４３８と、領域Ｅ３内又は領域Ｅ３と位置Ｌ１との間の第２層厚規制位置Ｌ２に対し隙間を隔てて設けられ、逆回転時におけるスリーブ部４６０が担持する現像剤の層厚を制限すると共に、逆回転方向Ｘ２の許容量以上の押圧力の作用に応じて弾性変形可能なシート部材６６６とを備える。【選択図】図２