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US 6,584,295 B2Granted
Method and apparatus for forming an image in a duplex print mode
AssigneeRicoh Company, Ltd.
InventorsYasukuni Omata, Hideaki Mochimaru
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Abstract
An image forming apparatus of the present invention is operable in a duplex print mode for printing images on both sides of a recording medium. A toner image is transferred from a first image carrier to a second image carrier and then transferred from the second image carrier to one side of the recording medium. Subsequently, a toner image is transferred from the first image carrier to the other side of the recording medium. After the toner image has been transferred from the first image carrier to the second image carrier, the second image carrier is moved in the reverse direction to a preselected position. The apparatus of the present invention enhances productivity in the duplex print mode.
Claims66
An image forming apparatus operable in a duplex print mode for printing images on both sides of a recording medium, said image forming apparatus comprising:
- a first image carrier configured to carry a toner image;
- a second image carrier positioned to receive the toner image from the first image carrier;
- a controller configured to control said first and second image carriers such that during the duplex print mode, after a first toner image is transferred from said first image carrier to said second image carrier, said second image carrier is moved in a reverse direction to a preselected position;
- and
- a fixing device positioned to fix at least the first toner image transferred onto the recording medium while said second image carrier and recording medium are lying on each other,
- wherein said second image carrier transfers the first toner image to one side of the recording medium and said first image carrier transfers a second toner image to the other side of said recording medium during the duplex print mode.
3 more elements
An image forming apparatus operable in a duplex print mode for printing images on both sides of a recording medium, said image forming apparatus comprising:
- a first image carrier configured to carry a toner image;
- a second image carrier positioned to receive the toner image from the first image carrier;
- first image transferring means for transferring the toner image from said first image carrier to one of said second image carrier and one side of the recording medium;
- and
- second image transferring means for transferring the toner image carried on said second image carrier to the other side of the recording medium;
- a controller configured to control said first and second image carriers such that during the duplex print mode, after a first toner image is transferred from said first image carrier to said second image carrier, said second image carrier is moved in a reverse direction to a preselected position,
- wherein during the duplex print mode, the first image transferring means transfers the first toner image from said second image carrier to one side of the recording medium, the second image transferring means transfers a second toner image from said first image carrier to the other side of said recording medium, and the first and second image transferring means prevent said second image carrier from being moved in the reverse direction when a toner image to be transferred to said second image carrier has a size larger than a preselected size.
4 more elements
An image forming apparatus operable in a duplex print mode for printing images on both sides of a recording medium, said image forming apparatus comprising:
- a first image carrier configured to carry a toner image;
- a second image carrier positioned to receive the toner image from the first image carrier;
- a polarity inverting device configured to invert a polarity of charge deposited on the toner image carried on said second image carrier;
- a controller configured to control said first and second image carriers such that during the duplex print mode, after a first toner image is transferred from said first image carrier to said second image carrier, said second image carrier is moved in a reverse direction to a preselected position;
- and
- a fixing device positioned to fix at least the first toner image transferred onto the recording medium while said second image carrier and recording medium are lying on each other,
- wherein said second image carrier transfers the first toner image to one side of the recording medium and said first image carrier transfers a second toner image to the other side of said recording medium during the duplex print mode.
4 more elements
An image forming apparatus operable in a duplex print mode for printing images on both sides of a recording medium, said image forming apparatus comprising:
- a first image carrier configured to carry a toner image;
- a second image carrier positioned to received the toner image from the first image carrier;
- image transferring means for transferring the toner image from said first image carrier to one of said second image carrier and one side of the recording medium and transferring the toner image from said second image carrier to the other side of said recording medium;
- a controller configured to control the first and second image carriers such that during the duplex print mode, after a first toner image is transferred from said first image carrier to said second image carrier, said second image carrier is moved in a reverse direction to a preselected position;
- and
- a polarity inverting device configured to invert a polarity of charge deposited on the toner image carried on said image carrier,
- wherein:
- said second image carrier transfers the first toner image to one side of the recording medium, and said first image carrier transfers a second toner image to the other side of said recording medium during the duplex print mode;
- and
- the image transferring means and polarity inverting device inhibit said second image carrier from being moved in the reverse direction when the toner image to be transferred to said second image carrier has a size larger than a preselected size.
7 more elements
An image forming method for transferring, in a duplex print mode, a toner image, the image forming method comprising:
- transferring a first toner image from a first image carrier to a second image carrier;
- moving said second image carrier in a reverse direction to a preselected position after said first toner image is transferred from said first image carrier to said second image carrier;
- transferring said first toner image from said second image carrier to one side of a recording medium;
- transferring a second toner image from said first image carrier to the other side of said recording medium;
- and
- fixing at least the first toner image transferred to the recording medium while said second image carrier and said recording medium are lying on each other.
3 more elements
An image forming method for transferring, in a duplex mode, a toner image, the image forming method comprising:
- transferring a first toner image from a first image carrier to a second image carrier with first image transferring means;
- moving said second image carrier in a reverse direction to a preselected position after said first toner image is transferred from said first image carrier to said second image carrier;
- transferring a second toner image from said first image carrier to one side of said recording medium with said first image transferring means;
- transferring said first toner image carried on said second image carrier to the other side of said recording medium with second image transferring means
- wherein said moving is inhibited when said first toner image to be transferred to said second image carrier has a size larger than a preselected size.
2 more elements
An image forming method for transferring, in a duplex print mode, a toner image, the image forming method comprising:
- transferring a first toner image from a first image carrier to a second image carrier;
- moving said second image carrier in a reverse direction to a preselected position after said first toner image is transferred from said first image carrier to said second image carrier;
- inverting a polarity of charge deposited on the first toner image carried on said second image carrier;
- transferring said first toner image from said second image carrier to one side of a recording medium;
- and
- transferring a second toner image from said first image carrier to the other side of said recording medium;
- fixing at least the first toner image transferred to the recording medium while said second image carrier and said recording medium are lying on each other.
4 more elements
An image forming method for transferring, in a duplex print mode, a toner image, the image forming method comprising:
- transferring a first toner image from a first image carrier to a second image carrier;
- moving said second image carrier in a reverse direction to a preselected position after said first toner image is transferred from said first image carrier to said second image carrier;
- inverting a polarity of charge deposited on the first toner image carried on said second image carrier;
- transferring said first toner image carried on said second image carrier to one side of said recording medium with a single image transferring means;
- transferring a second toner image from said first image carrier to the other side of said recording medium,
- wherein said moving is inhibited when said first toner image to be transferred to said second image carrier has a size larger than a preselected size.
3 more elements
An image forming apparatus operable in a duplex print mode for printing images on both sides of a recording medium, said image forming apparatus comprising:
- a first image carrier configured to carry a toner image;
- a second image carrier positioned to receive the toner image from the first image carrier;
- controlling means for controlling said first and second image carriers such that during the duplex print mode, after a first toner image is transferred from said first image carrier to said second image carrier, said second image carrier is moved in a reverse direction to a preselected position;
- and
- fixing means for fixing at least the first toner image transferred onto the recording medium while said second image carrier and recording medium are lying on each other,
- wherein said second image carrier transfers the first toner image to one side of the recording medium and said first image carrier transfers a second toner image to the other side of said recording medium during the duplex print mode.
3 more elements
An image forming apparatus operable in a duplex print mode for printing images on both sides of a recording medium, said image forming apparatus comprising:
- a first image carrier configured to carry a toner image;
- a second image carrier positioned to received the toner image from the first image carrier;
- controlling means for controlling the first and second image carriers such that during the duplex print mode, after said toner image is transferred from said first image carrier to said second image carrier, said second image carrier is moved in a reverse direction to a preselected position;
- and
- inhibiting means for inhibiting said second image carrier from being moved in the reverse direction when the toner image to be transferred to said second image carrier has a size larger than a preselected size,
- wherein said second image carrier transfers a first toner image to one side of the recording medium, and said first image carrier transfers a second toner image to the other side of said recording medium during the duplex print mode.
3 more elements
Dependencies are inferred from the claim text.