Canon Kabushiki Kaisha

Kohei Deno

Kunihiko Kitayama

Masaki Maeno

An image forming apparatus includes a re-conveyance portion to reverse a sheet on which a first toner image is transferred on a first surface by a transfer portion and to convey the sheet to the transfer portion again, and first and second detecting portions to detect positions in a widthwise direction of the sheet. The first detecting portion detects a first detecting position before the first toner image is transferred to the first surface and the second detecting portion detects a second detecting position after the first toner image is transferred and before a second toner image is transferred on a second surface. A controller determines a first image forming position where a latent image is formed on a photosensitive member before the first detecting position is detected and determines a second image forming position based on the first image forming position, and the first and second detecting positions.

Image forming apparatus

An image forming apparatus includes a controller to move a sheet, in an image formation process on a first surface, to a standard position in a width direction and move the sheet, in an image formation process on a second surface, in the width direction based on a detected position in a case where a difference between the standard position and a first position in the width direction is equal to or smaller than a predetermined value. The controller moves the sheet, in the image formation process on the first surface, by the predetermined value in the width direction and moves the sheet, in the image formation process on the second surface, in the width direction based on detected positions in a case where the difference between the standard position and the first position in the width direction is larger than the predetermined value.

Sheet control for image forming apparatus

An image forming apparatus includes an image forming portion to form an image on an image bearing member, and a transfer portion to transfer the image on a first image position on the image bearing member to a sheet. In addition, a controller determines a second image position, on the image bearing member, of an image to be transferred onto a second surface of a sheet re-conveyed to an adjustment portion by a reverse and re-conveyance portion based on a detected side edge position, of a trailing part of the sheet being conveyed with a first end as the leading edge. The trailing part of the sheet is positioned on a trailing edge side further than a center position, in the sheet conveyance direction, of the sheet, and the controller determines a shift amount based on the second image position and detected side edge position of the sheet, which has been re-conveyed, being conveyed with the second end as the leading edge.

Image forming apparatus capable of sheet position correction

An image forming apparatus is configured such that in a case where images are to be formed on a first surface of a preceding sheet, on a first surface of a succeeding sheet fed to the first conveyance path succeeding to the preceding sheet and on a second surface of the preceding sheet, a first conveyance member is stopped without reversing the preceding sheet to a second conveyance path in a case where the image has been formed on the first surface of the preceding sheet and permission of preparing the image to be formed on the first surface of the succeeding sheet is not issued yet. The first conveyance member restarts conveyance of the preceding sheet to the second conveyance path based on timing when an image forming unit starts preparing the image to be formed on the first surface of the succeeding sheet.

Image forming apparatus having controlled sheet feeding

A first conveyance member reverses a sheet received from a first conveyance path. Second through fourth conveyance members are disposed on a second conveyance path and convey a sheet from the first conveyance member toward the first conveyance path. A restriction portion is capable of restricting driving force of a first driving source from acting on a sheet through the second conveyance member. A controller executes a first operation and a second operation. In the first operation, a second driving source stops driving the third and fourth conveyance members while a first sheet is being nipped at the fourth conveyance member, and a second sheet is conveyed to be abutted with the third conveyance member. In the second operation, the second driving source starts driving the third and fourth conveyance members while the restriction portion restricts driving force of the first driving source from acting on the second sheet.

An image forming apparatus includes an image bearing member and an image forming portion configured to form first and second toner images on the image bearing member. A control portion controls the image forming portion such that a first toner image is formed on a first image position of the image bearing member, and a second toner image is formed on a second image position of the image bearing member. The sheet moves to a first sheet position corresponding to the first image position based on a first detection position before the first toner image is transferred onto a first surface of the sheet and moves, after being inverted, to a second sheet position corresponding to the second image position based on a second detection position before the second toner image is transferred onto a second surface of the sheet.

An image forming apparatus includes a control portion configured to control, based on a detection position of a sheet in a width direction, in a case where a center of an image formed on a first surface at an image forming portion in the width direction is displaced from a center of the sheet in the width direction at the image forming position and an image is to be formed on a second surface of the sheet, a moving portion to move the sheet in the width direction such that a position of the center of the sheet on a conveyance path in the width direction at the sheet forming position when the image is formed on the first surface and a position of a center of the sheet on the conveyance path in the width direction at the sheet forming position when the image is formed on the second surface coincide.

An image forming apparatus including an image bearing member, an image forming portion, a transfer portion, a moving portion, a re-conveyance portion, a detection portion, a detection portion, and a control portion is provided. The moving portion includes a sheet in a width direction, and the re-conveyance portion inverts the sheet bearing a toner image transferred onto a first surface thereof and conveys the sheet to the transfer portion again. The control portion controls the image forming portion to form the toner image for the first surface on a first image position and a toner image for a second surface on a second image position and controls the moving portion to move the sheet to a position corresponding to the first image position or the second image position.

According to the present disclosure, an image forming apparatus for minimizing a shift amount of the registration roller for the first and subsequent sheets is provided. The image forming apparatus forms an image on a sheet conveyed on a conveying path. The image forming apparatus includes an exposure device. Further, the image forming apparatus includes a pair of registration rollersconfigured to convey the sheet in a conveying direction with the sheet nipped by the pair of the registration rollers, and a detection unit configured to detect the side edge position in the width direction of the sheet conveyed. The control unitof the image forming apparatus determines the image writing position for the first sheet, and controls the image writing of the exposure device based on the detection result of the CISfor the first sheet.

A skew correction apparatus includes a first roller pair configured to nip a sheet to convey the sheet, a second roller pair provided upstream of the first roller pair and configured to nip the sheet and convey the sheet, a contact portion provided downstream of the first roller pair and configured to come in contact with a leading edge of the sheet conveyed with the first roller pair to correct a skew of the sheet, and a separation mechanism configured to set the second roller pair to a separated state before the skew of the sheet conveyed downstream with the first roller pair is corrected.

Skew correction apparatus and image forming apparatus having a control unit to control rollers

A sheet conveying apparatus includes first and second conveyance roller pairs, a width-direction shifting unit, first and second drive units, and a control unit. The second conveyance roller pair is arranged downstream of the first conveyance roller pair to nip and convey the sheet conveyed by the first conveyance roller pair, and to bend the sheet. The width-direction shifting unit shifts the sheet nipped by the second conveyance roller pair in a width direction by shifting the second conveyance roller pair in the width direction. The control unit controls the first and second drive units so that a circumferential speed of the first conveyance roller pair is made higher than that of the second conveyance roller pair between when the second conveyance roller pair starts conveying the sheet and when the width-direction shifting unit completes shifting the second conveyance roller pair in the width direction.

Sheet conveying apparatus and image forming apparatus

A skew correcting device includes a first roller pair configured to nip and convey a sheet, a second roller pair disposed upstream of the first roller pair and configured to nip and convey the sheet, a contact portion disposed downstream of the first roller pair, the contact portion being a portion that the leading edge of the conveyed sheet comes into contact to correct skew of the sheet, a switching mechanism configured to change a nipping force of the first roller pair before the leading edge of the conveyed sheet comes into contact with the contact portion to form a loop in the sheet, and a control unit configured to make a determination on the basis of sheet information as to whether the nipping force of the first roller pair is to be changed, the control unit being configured to control the switching mechanism on the basis of the determination.

Skew correcting device and image forming apparatus with separating mechanism

A sheet conveying apparatus has an upstream roller and a registration roller configured so that the sheet conveyed by the upstream roller abuts the registration roller to form a loop in the sheet to correct for skew. The skew of the sheet is corrected for by the leading edge of the sheet abutting the registration roller to bend the sheet so as to form the loop in the sheet. A resist sensor detects a time difference of passing time between the advanced leading edge and the retarded leading edge in the downstream leading edge of the sheet conveyed by the upstream roller, detects the skew amount of the sheet based on the time difference, and changes the backward rotation time of the registration roller depending on the skew amount.

A driving force transmitting apparatus includes a driving source, a drive pulley rotatable by a driving force supplied from the driving source, a follower pulley rotatable with a member to be rotated, and a belt member extending around a cylindrical surface of the driving pulley and a cylindrical surface of the follower pulley. In addition, an intermediate transmission member contacts the driving pulley and the follower pulley, and the intermediate transmission member has a rigidity higher than that of the belt member.

Driving force transmitting device and image forming apparatus including the same

The skew-feeding correcting apparatus of the present invention includes an abutment portion which is disposed to a conveying path to convey a sheet and to which a top end of the sheet is abutted to correct skew feeding of the sheet, a movement portion which moves the abutment portion in a sheet width direction perpendicular to a sheet conveyance direction, and a controller which controls driving of the movement portion to move the abutment portion to a position where a corner part of the sheet is not to be abutted to the abutment portion before the top end of the sheet is abutted to the abutment portion.

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Moriya, Japan

Kohei Deno