US 7,366,438 B2
Image forming apparatus which can optimize cleaning time of transfer member contacting inter-image area of image bearing member
Yasushi Takeuchi, Toride (Japan); Yuichi Ikeda, Abiko (Japan); and Jun Tomine, Abiko (Japan)
Assigned to Canon Kabushiki Kaisha, Tokyo (Japan)
Filed on Apr. 16, 2007, as Appl. No. 11/735,759.
Application 11/735759 is a division of application No. 11/149540, filed on Jun. 10, 2005, granted, now 7,242,887.
Claims priority of application No. 2004-180228 (JP), filed on Jun. 17, 2004.
Prior Publication US 2007/0183801 A1, Aug. 09, 2007
This patent is subject to a terminal disclaimer.
Int. Cl. G03G 15/16 (2006.01)
U.S. Cl. 399—101  [399/66] 4 Claims
OG exemplary drawing
 
1. An image forming apparatus comprising:
an image bearing member;
toner image forming means for repeatedly forming a plurality of toner images on said image bearing member, said toner image forming means forming a detection patch in an inter-toner image area on said image bearing member;
a transfer member which contacts said image bearing member to form a transfer nip portion, said transfer member electrically transferring the toner image formed on said image bearing member to the recording material in the transfer nip portion;
detecting means for detecting the detection patch on said image bearing member;
controlling means for variably controlling a toner image forming condition of said toner image forming means based on the detection result of said detecting means; and
toner removing means for forming a cleaning electric field to remove toner adhering to said transfer member when the inter-toner image area passes through the transfer nip portion, the cleaning electric field electrostatically moving the toner adhering to said transfer member to said image bearing member,
wherein a length of time of the cleaning electric field formed in a time period when the inter-toner image area on which the detection patch is formed passes through the transfer nip portion, is longer than a length of time of the cleaning electric field formed in a time period when the inter-toner image area on which the detection patch is not formed passes through the transfer nip portion.