1. Field of the Invention
This invention relates to an image forming apparatus such as a copying machine or a printer adopting an electrophotographic recording method, an electrostatic recording method or the like, and particularly to an image forming apparatus having air blowing means for blowing air to the underside of a recording material discharged by discharging means.
2. Related Background Art
There has heretofore been such an apparatus for cooling a recording material immediately behind a pair of conveyance rollers as described in Japanese Patent Application Laid-open No. 2003-208043 in order to prevent an inconvenience from occurring in the apparatus due to the heat of a recording material heated and fixed by fixing means.
An apparatus of this kind is shown in FIG. 6 of the accompanying drawings. As shown in FIG. 6, a recording material S having reached a high temperature by a toner image thereon being fixed by a fixing device 300 passes between a pair of conveyance rollers 130 and 140 and is discharged onto a sheet discharge tray 150, and design is made such that this recording material S receives air from a fan 200 immediately behind the pair of conveyance rollers 130 and 140.
Thereby, it becomes possible to cool the recording material S, and it is possible to prevent the phenomenon that plastic film sheets such as OHT sheets stick to each other on the sheet discharge tray 150 due to the high temperature thereof, or prevent the temperature of the sheet discharge tray 150 from rising too much to thereby adversely affect the temperature of the interior of an image forming apparatus 500. Further, in a case where the image forming apparatus 500 can form images on the two sides of the recording material S, each one side of the recording material S can be cooled, and the temperature rise in the interior of the image forming apparatus 500 can be prevented to thereby form images of good quality on the recording material S.
Now, if in the above-described apparatus, the shape of the pair of conveyance rollers 130 and 140 is that of through rollers straight and continuous in the longitudinal direction thereof, the waving of the recording material will not occur, but yet correspondingly, the entire recording material may sometimes be rounded on the sheet discharge tray, and in some cases the stackability of the recording material has been deteriorated.
In order to solve this problem, the applicant has proposed in Japanese Patent Application No. 2004-315229 air blowing means set so as to prevent the rounding of a recording material by air from a fan raising and conveying the recording material.
In the proposed apparatus mentioned above, when recording materials are stacked up to near the air outlet of the air blowing means, although within a range substantially free of a problem, the stackability and alignment of the recording materials are somewhat disturbed by the air, and a further improvement has been desired from the viewpoint of an apparatus which is better in the handling of the recording materials.