1. Field of the Invention
The present invention relates to an image forming apparatus, such as a copying machine and a printer, which uses an electrophotographic method or an electrostatic recording method, and more particularly, to an image forming apparatus including a cleaning blade.
2. Description of the Related Art
Conventionally, for example, in an electrophotographic image forming apparatus, an electrostatic image (latent image) formed on an electrophotographic photosensitive member (photosensitive member) is developed with toner to form a toner image. Then, the toner image formed on the photosensitive member is ultimately transferred onto a recording material (recording sheet, OHP sheet, etc.) to be fixed thereto and output from the image forming apparatus. Examples of a method of transferring a toner image formed on a photosensitive member onto a recording material include: a direct transfer method of directly transferring a toner image formed on a photosensitive member onto a recording material; and an intermediate transfer method of transferring a toner image formed on a photosensitive member onto an intermediate transfer member once and then transferring the toner image transferred on the intermediate transfer member onto a recording material.
When the above-mentioned photosensitive member or an image bearing member such as an intermediate transfer member once holds a toner image and then transfers the toner image onto a transfer target member, toner remains on the surface of the photosensitive member or the image bearing member without being transferred. Therefore, it is necessary to clean the surface so as to form a subsequent image. Conventionally, a cleaning blade method of removing remaining toner by bringing a cleaning blade into abutting contact with the surface of the image bearing member has been widely adopted.
If a friction force between the cleaning blade and the image bearing member is too large when the cleaning blade is brought into abutting contact with the surface of the image bearing member, an abutment portion of the cleaning blade may be turned up, resulting in blade turning up. Further, even when the blade turning up does not occur, the surface of the image bearing member may be scraped or scratched to cause an image defect. In order to prevent this problem, a technology has been proposed, which prevents the blade from being turned up or the image bearing member from being scratched as described above by applying a lubricant to the image bearing member to lower a surface energy of the image bearing member and to reduce a friction force between the image bearing member and the cleaning blade (Japanese Patent Application Laid-Open No. 2007-241114).
However, in an application of lubricant to the image bearing member, when the rotation of the image bearing member is suspended, a state in which the lubricant is applied to a region of the image bearing member from a contact portion between the image bearing member and a lubricant applying unit to a cleaning blade nip portion is left as it is.
At this time, particularly, the lubricant sandwiched between the lubricant applying unit and the image bearing member is pressurized against the image bearing member. Therefore, the lubricant may adhere to the image bearing member. The lubricant adhering to the image bearing member does not function as a lubricant with respect to the cleaning blade, and when the lubricant enters the nip portion between the cleaning blade and the image bearing member, the lubricant rather causes the cleaning blade to be turned up or chipped and the surface of the image bearing member to be scratched.