US 6,088,567 AGranted

Image forming device with different fixing speeds

AssigneeCanon Kabushiki Kaisha

InventorsToshiaki Miyashiro, Akihiko Takeuchi, Takehiko Suzuki, Takaaki Tsuruya

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Abstract

In an image forming apparatus a length of a transfer material in a conveying direction thereof is L.sub.p, a length of a toner image transferred onto an intermediate transfer belt in a shifting direction is L.sub.p ', a distance between a first transfer portion t.sub.1 and a second transfer portion t.sub.2 along the shifting direction of the intermediate transfer belt is L.sub.t1-t2 and a distance between the second transfer portion t.sub.2 and a fixing portion fix along the shifting direction of the transfer material is L.sub.t2-fix, so that the following relation is established: L.sub.t1-t2 >L.sub.p ' and L.sub.p >L.sub.t2-fix. After a first transfer is complete and before initiation of a second transfer, the speed of the intermediate transfer belt is decreased, so that, following to the second transfer process at a low speed, the toner image can be fixed onto the transfer material at a low speed. With this arrangement, the distance L.sub.t2-fix between the second transfer portion and the fixing portion is reduced to make the apparatus compact and the reduction of the through-put can be prevented while preventing poor fixing.

Claims52

Dependent claims

An image forming apparatus comprising:

a moveable image bearing member for bearing a toner image;
a moveable intermediate transfer member onto which the toner image on said image bearing member is transferred at a first transfer position and in which a moving speed of which can be switched between a first moving speed and a second moving speed slower than said first moving speed;
and
a moveable fixing means for fixing the toner image onto a transfer material at a fixing position after the toner image on said intermediate transfer member is transferred onto the transfer material at a second transfer position, said fixing means effecting fixing at a first fixing speed when the toner image on said intermediate transfer member is transferred onto the transfer material at said first moving speed, and effecting fixing at a second fixing speed slower than said first fixing speed when the toner image on said intermediate transfer member is transferred onto the transfer material at said second moving speed;
wherein a distance from said first transfer position to said second transfer position along a moving direction of said intermediate transfer member is longer than a length of the toner image on said intermediate transfer member in the moving direction thereof, and a distance from said second transfer position to said fixing position is shorter than a length of the transfer material along a conveying direction thereof;
and
after the toner image is transferred from said image bearing member to said intermediate transfer member and before the toner image on said intermediate transfer member reaches said second transfer position, the toner image on said intermediate transfer member does not pass through said first transfer position, and the moving speed of said intermediate transfer member can be switched from said first moving speed to said second moving speed.

4 more elements

An image forming apparatus comprising:

a moveable image bearing member for bearing a toner image;
a moveable intermediate transfer member onto which the toner image on said image bearing member is transferred at a first transfer position and in which a moving speed of which can be switched between a first moving speed and a second moving speed slower than said first moving speed;
and
a moveable fixing means for fixing the toner image onto a transfer material at a fixing position after the toner image on said intermediate transfer member is transferred onto the transfer material at a second transfer position, said fixing means effecting fixing at a first fixing speed when the toner image on said intermediate transfer member is transferred onto the transfer material at said first moving speed, and effecting fixing at a second fixing speed slower than said first fixing speed when the toner image on said intermediate transfer member is transferred onto the transfer material at said second moving speed;
wherein a distance from said first transfer position to said second transfer position along a moving direction of said intermediate transfer member is longer than a length of the transfer material in a conveying direction thereof, and a distance from said second transfer position to said fixing position in the conveying direction of the transfer material is shorter than the length of the transfer material along the conveying direction thereof;
and
after the toner image is transferred from said image bearing member to said intermediate transfer member and before the toner image on said intermediate transfer member reaches said second transfer position, the toner image on said intermediate transfer member does not pass through said first transfer position and the moving speed of said intermediate transfer member can be switched from said first moving speed to said second moving speed.

4 more elements

An image forming apparatus comprising:

a moveable image bearing member for bearing a toner image;
a moveable intermediate transfer member onto which the toner image on said image bearing member is transferred at a first transfer position and in which a moving speed of which can be switched between a first moving speed at which the toner image on said image bearing member is transferred onto said intermediate transfer member and a second moving speed slower than said first moving speed;
and
moveable fixing means for fixing the toner image onto a transfer material at a fixing position after the toner image on said intermediate transfer member is transferred onto the transfer material at a second transfer position, said fixing means effecting fixing at a speed slower than said first moving speed,
wherein a distance from said first transfer position to said second transfer position along a moving direction of said intermediate transfer member is longer than a length of the toner image on said intermediate transfer member in the moving direction thereof, and a distance from said second transfer position to said fixing position is shorter than a length of the transfer material along a conveying direction thereof;
and
after the toner image is transferred from said image bearing member to said intermediate transfer member and before the toner image on said intermediate transfer member reaches said second transfer position, the toner image on said intermediate transfer member does not pass through said first transfer position, and the moving speed of said intermediate transfer member can be switched from said first moving speed to said second moving speed.

4 more elements

An image forming apparatus comprising:

a moveable image bearing member for bearing a toner image;
a moveable intermediate transfer member onto which the toner image on said image bearing member is transferred at a first transfer position and in which a moving speed of which can be switched between a first moving speed at which the toner image on said image bearing member is transferred onto said intermediate transfer member and a second moving speed slower than said first moving speed;
and
moveable fixing means for fixing the toner image onto a transfer material at a fixing position after the toner image on said intermediate transfer member is transferred onto the transfer material at a second transfer position, said fixing means effecting fixing at a speed slower than said first moving speed,
wherein a distance from said first transfer position to said second transfer position along a moving direction of said intermediate transfer member is longer than a length of the transfer material in a conveying direction thereof, and a distance from said second transfer position to said fixing position in the conveying direction of the transfer material is shorter than the length of the transfer material along the conveying direction thereof;
and
after the toner image is transferred from said image bearing member to said intermediate transfer member and before the toner image on said intermediate transfer member reaches said second transfer position, the toner image on said intermediate transfer member does not pass through said first transfer position, and the moving speed of said intermediate transfer member can be switched from said first moving speed to said second moving speed.

4 more elements

Dependencies are inferred from the claim text.