IMAGE FORMING APPARATUS USING CLEANER-LESS SYSTEM

• US 20100124436A1
• Filed: 11/17/2009
• Published: 05/20/2010
• Est. Priority Date: 11/19/2008
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kinokuni, Jiro
• Granted Patent: US 8,315,541 B2
• Time in Patent Office: Days
• US Class Current: 399/168
• CPC Class Codes: G03G 15/0233 Structure, details of the charging member, e.g. chemical composition, surface properties
• CPC Class Codes: G03G 15/0898 for preventing toner scattering during operation, e.g. seals sealing the donor member G03G15/0817; sealing the magnetic brush G03G15/0942
• CPC Class Codes: G03G 15/161 with means for handling the intermediate support, e.g. heating, cleaning, coating with a transfer agent
• CPC Class Codes: G03G 15/162 details of the the intermediate support, e.g. chemical composition
• CPC Class Codes: G03G 15/75 Details relating to xerographic drum, band or plate, e.g. replacing, testing electrographic recording members per se G03G5/00
• CPC Class Codes: G03G 21/1821 means for connecting the different parts of the process cartridge, e.g. attachment, positioning of parts with each other, pressure/distance regulation G03G21/1825 takes precedence
• CPC Class Codes: G03G 2215/1614 Transfer roll

Abstract

An image forming apparatus includes a rotatable photosensitive member; a charging device for electrically charging the photosensitive member; a developing device for developing with toner an electrostatic latent image formed on the photosensitive member electrically charged by the charging device; a transfer device for transferring a toner image from the photosensitive member onto an image-receiving member; and an auxiliary charging device for electrically charging untransferred toner on the photosensitive member to a normal charge polarity before the photosensitive member is electrically charged by the charging device; wherein effective widths W_PM, W_CD, W_TD, and W_ACD of the photosensitive member, the charging device, the developing device, the transfer device, and the auxiliary charging device satisfy:

W_PM>W_CD>W_ACD≧W_TD>W_DD.

Claims

1. An image forming apparatus comprising:

a rotatable photosensitive member;

a charging device for electrically charging said photosensitive member;

a developing device for developing with toner an electrostatic latent image formed on said photosensitive member electrically charged by said charging device;

a transfer device for transferring a toner image from said photosensitive member onto an image-receiving member; and

an auxiliary charging device for electrically charging untransferred toner on said photosensitive member to a normal charge polarity before said photosensitive member is electrically charged by said charging device;

wherein effective widths W_PM, W_CD, W_DD, W_TD, and W_ACD of said photosensitive member, said charging device, said developing device, said transfer device, and said auxiliary charging device, respectively, satisfy;

W_PM>

W_CD>

W_ACD≧

W_TD>

W_DD.

2. An apparatus according to claim 1, further comprising a reciprocally moving device for reciprocally moving said auxiliary charging device in a rotation shaft direction of said photosensitive member,

wherein a width W_MAX in which said auxiliary charging device is moved by said reciprocally moving device, and the effective widths W_PM, W_CD, and W_ACD satisfy:

W_PM>

W_MAX>

W_CD>

W_ACD.

3. An apparatus according to claim 2, wherein the widths W_CD, W_ACD, W_TD, and W_DD satisfy:

(W_CD−

W_ACD)>

(W_TD−

W_DD).