US 2012/0237236 A1Published application

Image forming apparatus and image forming method

AssigneeKonica Minolta Business Technologies, Inc.

InventorYohei NAKADE

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Abstract

Image forming apparatus to expose-scan electrically charged surface of image carrier based on image data in unit of page to form electrostatic latent image, and develop electrostatic latent image at development position on image carrier by using developer carried by developer carrier. The image forming apparatus determines, based on image data of page, first and second partial regions having first and second attributes in page, not overlapping in sub scanning direction, and switches development bias voltage value and/or rotational speed of developer carrier to value for first attribute while electrostatic latent image on image carrier corresponding to first partial region passes through development position, and to value for second attribute while electrostatic latent image corresponding to second partial region passes through development position.

Claims18

Dependent claims

An image forming apparatus to expose-scan an electrically charged surface of an image carrier in accordance with image data in unit of page to form an electrostatic latent image on the image carrier, and develop the electrostatic latent image at a development position on the image carrier by using developer carried by a developer carrier, the image forming apparatus comprising:

a drive unit driving the developer carrier to rotate;
a power source supplying a development bias voltage including a DC component and an AC component to the developer carrier;
a determination unit determining, in accordance with image data of a page, a first partial region having a first attribute and a second partial region having a second attribute, the first and second partial regions being included in the page and not overlapping with each other in a sub scanning direction;
and
a controller switching at least one of a development bias voltage value and a rotational speed of the developer carrier to a value for the first attribute while a portion of an electrostatic latent image of the page formed on the image carrier corresponding to the first partial region passes through a development position, and to a value for the second attribute while a portion of the electrostatic latent image of the page formed on the image carrier corresponding to the second partial region passes through the development position, the value for the first attribute and the value for the second attribute being different values.

2 more elements

An image forming method for an image forming apparatus to expose-scan an electrically charged surface of an image carrier in accordance with image data in unit of page to form an electrostatic latent image on the image carrier, and develop the electrostatic latent image at a development position on the image carrier by using developer carried by a developer carrier, the image forming method comprising the steps of:

determining, in accordance with image data of a page, a first partial region having a first attribute and a second partial region having a second attribute, the first and second partial regions being included in the page and not overlapping with each other in a sub scanning direction;
and
controlling to switch at least one of a development bias voltage value and a rotational speed of the developer carrier to a value for the first attribute while a portion of an electrostatic latent image of the page formed on the image carrier corresponding to the first partial region passes through a development position, and to a value for the second attribute while a portion of the electrostatic latent image of the page formed on the image carrier corresponding to the second partial region passes through the development position, the value for the first attribute and the value for the second attribute being different values.

Dependencies are inferred from the claim text.