1. Field of the Invention
This invention relates to a cleaning apparatus for cleaning (removing) a toner from a member to be cleaned such as an image bearing member, and further to an image forming apparatus such as a copier, a printer or a facsimile apparatus which can use such cleaning apparatus.
2. Related Background Art
In a well-known image forming apparatus which repeats the step of transferring a toner image formed on the surface of an image forming member being moved to a recording material such as paper, it is difficult for all the toner to be completely transferred to the recording material during transfer, and after the transfer, part of the toner unavoidably remains on the surface of the image bearing member.
Accordingly, it is a requisite condition for obtaining image of good quality to sufficiently remove the residual toner before entering the next image forming step, and as a cleaning apparatus for that purpose, an apparatus in which a cleaning blade formed of an elastic material such as urethane rubber closely contacts with the surface of the image bearing member to thereby remove any residual toner which has not contributed to the transfer is simple and compact in construction and is excellent in the toner removing function and has therefore been widely used heretofore.
Now, among cleaning apparatuses, there is one designed such that collected toner is directed to a toner carrying path in the apparatus, and the toner is carried by a toner carrying screw member provided in this toner carrying path and this toner is contained and collected as a waste toner in a collected toner bottle or the like.
In recent years, however, it has become the mainstream to dispose a photosensitive drum and a fixing apparatus in proximity to each other to downsize the copier and shorten FCOT (first copy time) which is the first copy discharge time, and the fixing apparatus is disposed just near the cleaning apparatus, and the cleaning apparatus becomes liable to be affected by the heat of the fixing apparatus.
Also, from the viewpoint of using a toner of a low melting point from the necessity of curtailing electric power concerned in fixing as an energy saving countermeasure, or making the quality of image high, the development for making the particles of the toner finer has been advanced, and the following problems have arisen in the development of such a toner.
That is, in a cleaning apparatus 30 shown in FIG. 9 of the accompanying drawings, a screw of a spiral shape having a shaft 35a as shown in FIG. 10 of the accompanying drawings is often used as a carrying screw 35, and in this carrying screw 35, the outer diameter thereof is 15.4 mm, whereas the diameter of the shaft thereof is about 8 mm. This carrying screw 35 is rotated in the direction of arrow S in FIG. 10, whereby a waste toner is carried in the direction of arrow T.
There has arisen the problem that the waste toner remaining not carried by the carrying screw 35 is packed in a space surrounded by a cleaning member 34 and a scooping sheet 36 shown in FIG. 9, and this packed waste toner is heated by the heat of a fixing apparatus 40 disposed near the cleaning apparatus 30 and is crushed against an image bearing member 20, and is mechanically damaged and fused on the surface of the image bearing member 20. Particularly, the above-noted problem is liable to arise in a toner lowered in its melting point or a toner using a resin binder of low hardness to make the particles thereof finer.
It is an object of the present invention to provide a cleaning apparatus and an image forming apparatus which prevent the fusion of waste toner onto an image bearing member.
It is another object of the present invention to provide a cleaning apparatus and an image forming apparatus which removes a toner well.
Further objects and features of the present invention will become more fully apparent from the following detailed description when read with reference to the accompanying drawings.