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AssigneeCanon Kabushiki Kaisha
InventorYoichiro Maebashi
Estimating the term…
The voltage value or frequency of an AC voltage component applied to charging rollers in a mono-colored black image forming mode is reduced so as to be smaller than the value or frequency applied in the full-colored image forming mode. In this manner, in the mono-colored black image forming mode, electric discharge between the charging rollers and photosensitive drums which does not form images is reduced, so that a shaving-off phenomenon on the surfaces of the photosensitive drums can be decrease, thereby increasing a lifespan of the photosensitive drums.
An image forming apparatus comprising:
An image forming apparatus comprising:
Dependencies are inferred from the claim text.
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From the US filing history. Foreign family members aren’t listed.
For producing multicoloured copies: details of unit
Plural electrographic recording members: linear arrangement adjacent plural transfer points
Arrangements for laying down a uniform charge: by contact, friction or induction
Electrography
Term ended 6 Mar 2021 (estimated)
1. Field of the Invention
The present invention relates to an image forming apparatus employing an electrophotographic system therein, and in particular relates to an image forming apparatus for use in copying machines and facsimile machines, etc., for example.
2. Description of the Related Art
Further objects, features and advantages of the present invention will become apparent from the following description of the preferred embodiments with reference to the attached drawings.
FIG. 1 is a schematic block diagram of an image forming apparatus according to a first embodiment of the present invention;
FIG. 2 is a schematic block diagram of an image forming apparatus according to a second embodiment of the present invention;
Embodiments according to the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic block diagram of an image forming apparatus according to a first embodiment of the present invention (a tandem-type full-colored image forming apparatus employing an electrophotographic system therein in this embodiment).
The image forming apparatus comprises four image forming sections (image forming units) which are an image forming section 1M for forming a magenta image, an image forming section 1C for forming a cyan image, an image forming section 1Y for forming a yellow image, and an image forming section 1BK for forming a black image, and these four image forming sections are arranged in a line and spaced at predetermined intervals.