JP2012032502A5 - - Google Patents

Description

The image forming operation of the image forming apparatus of this embodiment will be described with reference to FIG. The control unit 100 sequentially drives the image forming units Pa, Pb, Pc, and Pd according to an image forming sequence that is executed in response to a print command. First, each photosensitive drum 1 is rotated in the arrow direction at a predetermined peripheral speed (process speed), and the intermediate transfer belt 7 is driven in the arrow direction at a peripheral speed corresponding to the rotational peripheral speed of each photosensitive drum 1 by the drive roller 8a. It is rotated. In the first color cyan image forming portion Pa, the surface of the photosensitive drum 1 is uniformly charged by the drum charger 2 to a predetermined polarity and potential. Next, the scanning exposure device 3 scans and exposes the charged surface of the photosensitive drum 1 with laser light corresponding to image data (image information) output from the external device. As a result, an electrostatic latent image (electrostatic image) corresponding to the image data is formed on the charging surface of the photosensitive drum 1 surface. The electrostatic latent image is developed by the developing device 4 using cyan toner. As a result, a cyan toner image (development image) is formed on the surface of the photosensitive drum 1. Similar charging, exposure, each step of developing is carried out also in the second color image forming unit for magenta Pb, 3 an image forming section of the color of Lee Yellow Pc, 4-color black image forming section Pd. Each color toner image formed on the surface of each photosensitive drum 1 is sequentially transferred onto the surface of the intermediate transfer belt 7 by the primary transfer roller 5 at the primary transfer nip portion between the surface of the photosensitive drum and the surface of the intermediate transfer belt 7. The As a result, a full-color toner image is carried on the surface of the intermediate transfer belt 7. The toner remaining on the surface of the photosensitive drum 1 after the transfer of the toner image is removed by the drum cleaner 6 to be used for the next image formation.

The heating unit 22 is arranged in parallel with the fixing roller 20 above the fixing roller 20. Then, both ends in the longitudinal direction of the heater holder 24 are urged toward the fixing roller 20 in the radial direction of the flexible film 25 with a predetermined pressure by a pressure spring (not shown). As a result, the heater 23 is pressed against the surface of the fixing roller 20 with the flexible film 25 interposed therebetween. Thus, the elastic layer 20B of the fixing roller 20 is elastically deformed, and a heating nip portion Nk having a predetermined width is formed between the surface of the fixing roller 20 and the outer peripheral surface (surface) of the flexible film 25. The heating means is not limited to the heating unit 22, and a heating roller containing a halogen heater may be used.

As described above, in the fixing roller recovery mode, an excellent wrinkle extending effect was obtained for the release layer 20C of the fixing roller 20. The wrinkle-stretching effect is not temporary, and is maintained for a certain period of time from when the fixing roller recovery mode is performed until the stress to keep the smooth shape does not work on the release layer 20C. Even if wrinkles occur again in the release layer 20C of the fixing roller 20, the fixing roller recovery mode may be selected again.

Claims (6)

An image forming unit for forming an unfixed image on a recording material;
A fixing rotator having an elastic body below the surface layer, the fixing rotator forming a heating nip when the heating means and the surface layer are in contact with each other, and the heating nip A fixing unit that heats the fixing rotator by the heating unit and heat-fixes an unfixed image formed on the recording material to the recording material by the fixing rotator; and
In the image forming apparatus capable of selecting the surface layer shape recovery mode of the fixing rotator,
When the surface layer shape recovery mode is selected, the heating means heats the surface layer at a predetermined target temperature lower than the melting point of the material of the surface layer of the fixing rotator, and the heating means An image forming apparatus characterized in that the peripheral speed of the fixing rotator is switched so that the amount of heat per unit area when performing the above heating becomes larger than when heating and fixing an unfixed image on a recording material.   The peripheral speed of the fixing rotator is slower when the surface layer shape recovery mode is selected than when an unfixed image is heat-fixed on a recording material. Image forming apparatus. When the surface layer shape recovery mode is selected, while performing starts and stops rotation of the fixing rotator, by the heating means to claim 1 or claim 2, characterized in that for heating of the surface layer The image forming apparatus described. When the surface layer shape recovery mode is selected, while still the fixing rotator, image according to claim 1 or claim 2, characterized in that performing the heating of the surface layer by the heating means Forming equipment. The surface layer, the image forming apparatus according to any one of claims 1 to 4, characterized in that it is formed by coating. The material of the surface layer, the image forming apparatus according to any one of claims 1 to 5, characterized in that a main component a fluorine compound.