JP2016009134A5

JP2016009134A5 -

Info

Publication number: JP2016009134A5
Application number: JP2014130716A
Authority: JP
Filing date: 2014-06-25
Publication date: 2017-08-03

Description

本発明の画像形成装置は、一枚ずつ搬送されるシートに、色毎に形成される単色の画像を重畳して画像形成を行う画像形成装置であって、前記色毎に配備された感光体と、前記色毎に配備され、前記感光体の表面に形成された潜像をトナーにより現像する現像手段と、前記色毎の前記感光体に当接して前記現像手段により現像されたトナー像が転写される中間転写体と、黒以外の色の前記感光体と前記中間転写体とが当接した状態または離間した状態にさせる当接離間機構と、前記形成する画像が複数色からなるカラー画像であるか、又は黒単色の画像であるかを判別する判別手段と、前記カラー画像と判別された場合には、前記複数色の感光体を前記中間転写体に当接させ、且つ、当該複数色の現像手段が動作する第一の印刷モードで画像形成を行うように制御し、前記黒単色の画像と判別された場合には、前記黒以外の色の前記現像手段の動作を停止する第二の印刷モードで画像形成を行うように制御する制御手段と、を有し、前記制御手段は、第１のシートに後続する第２のシートに形成する画像が前記黒単色の画像であり、且つ、前記第１のシートと前記第２のシートとのシート間隔が所定の間隔未満である場合には、前記第２のシートに形成すべき画像を前記第二の印刷モードで形成を行うように制御し、前記シート間隔が前記所定の間隔以上である場合には、前記黒以外の色の前記感光体を前記中間転写体から離間させるとともに前記黒以外の色の前記現像手段の動作を停止する第三の印刷モードで画像形成を行うように制御することを特徴とする。
The image forming apparatus of the present invention is an image forming apparatus that forms an image by superimposing a single-color image formed for each color on a sheet conveyed one by one, and a photoconductor provided for each color When being deployed for each of the colors, the latent images formed on the surface of the photosensitive member and developing means for developing the toner, the toner image developed by the developing unit in contact with the photosensitive member of each of the color An intermediate transfer member to be transferred, a contact / separation mechanism for bringing the photoconductor of a color other than black and the intermediate transfer member into contact with or separated from each other, and a color image in which the image to be formed is a plurality of colors Or a black monochrome image, and when the color image is determined, the plurality of color photoconductors are brought into contact with the intermediate transfer member, and the plurality The image in the first printing mode in which the color developing means operates Controlled so as to perform formation, when it is determined that the black monochrome image, control for controlling to perform image formation in the second print mode for stopping the operation of the developing unit of a color other than the black and means, possess, said control means is a second image of the image is the black monochrome forming the sheet following the first sheet, and, with the first sheet and the second sheet When the sheet interval is less than the predetermined interval, control is performed so that an image to be formed on the second sheet is formed in the second print mode, and the sheet interval is equal to or greater than the predetermined interval. In some cases, control is performed so as to form an image in a third printing mode in which the photosensitive member of a color other than black is separated from the intermediate transfer member and the operation of the developing unit of a color other than black is stopped. characterized in that it.

Claims

An image forming apparatus for forming an image by superimposing a single color image formed for each color on a sheet conveyed one by one,
A photoreceptor arranged for each color;
Developing means arranged for each color and developing the latent image formed on the surface of the photoreceptor with toner;
An intermediate transfer member to which the toner image developed by the developing means is transferred in contact with the photosensitive member for each color ;
A contact / separation mechanism for bringing the photoconductor of a color other than black and the intermediate transfer body into contact with or separated from each other;
A discriminating means for discriminating whether the image to be formed is a color image composed of a plurality of colors or a black monochromatic image;
When it is determined that the image is a color image, the plurality of color photosensitive members are brought into contact with the intermediate transfer member, and image formation is performed in a first printing mode in which the plurality of color developing units operate. controlling, when it is determined that the black monochrome image, have a, and control means for controlling to perform image formation in the second print mode for stopping the operation of the developing unit of a color other than the black And
In the control unit, an image formed on a second sheet subsequent to the first sheet is the monochrome image, and a sheet interval between the first sheet and the second sheet is a predetermined interval. If the sheet interval is less than the predetermined interval, control is performed so that the image to be formed on the second sheet is formed in the second print mode. The photosensitive member of a color other than that is separated from the intermediate transfer member and controlled to perform image formation in a third print mode in which the operation of the developing unit of a color other than black is stopped .
Image forming apparatus.

And further has a counting means for counting the number of times that a black monochrome image is continuously formed,
When the image formed on the subsequent sheet is the black monochrome image and the number of times counted by the counting unit is less than a predetermined value, the control unit performs the image in the second printing mode. Control to perform the formation, and if the predetermined value is exceeded, control to perform the image formation in the third print mode,
The image forming apparatus according to claim 1 .

The control means performs the operation of the developing means when the image formed on the succeeding sheet is the black monochrome image and the number counted by the counting means exceeds the predetermined value. The image forming device is controlled to perform image formation in a fourth printing mode in which the photoconductors of colors other than black are separated from the intermediate transfer member while maintaining
The image forming apparatus according to claim 2 .

Temperature detecting means for detecting an excessive temperature rise in a fixing unit for fixing the toner image transferred to the sheet;
And an adjustment unit that adjusts the sheet interval by delaying the start of feeding of the next sheet when the excessive temperature rise is detected compared to when the excessive temperature rise is not detected. And
The image forming apparatus according to claim 1 or 3.

When the image formed on the succeeding sheet is the black monochrome image and the sheet interval after adjustment by the adjustment unit is equal to or greater than a predetermined interval, the control unit performs the third printing mode. Control to perform image formation with
The image forming apparatus according to claim 4 .

The control unit performs control so that an operation of separating the photosensitive member of the color other than black from the intermediate transfer member is started after the operation of the developing unit of all colors other than black is stopped. Features
The image forming apparatus according to any one of claims 1 to 5.

An image forming unit including a plurality of image forming units provided corresponding to a plurality of color components, each including a photosensitive member and a developing unit that develops the latent image formed on the photosensitive member with toner;
An intermediate transfer member onto which the developed toner images are transferred to the photosensitive members of the plurality of image forming units;
A first state in which the intermediate transfer member is in contact with only the photosensitive member of the image forming unit corresponding to a predetermined color component in the plurality of image forming units; and all the photosensitive members of the plurality of image forming units; A switching mechanism for switching between the contacted second state;
Determining means for determining whether the image formed by the image forming means is a color image or a monochrome image;
When the switching mechanism determines that the image to be formed next is a monochrome image while being switched to the second state, the transport interval of the transported sheets is When it is longer than the time required for switching from the second state to the first state by the switching mechanism, the switching mechanism switches from the second state to the first state to form the monochrome image, and a plurality of conveyed images When the sheet conveyance interval is shorter than the time required for switching from the second state to the first state by the switching mechanism, the image forming unit is controlled to form the monochrome image in the second state. And a control means.
Image forming apparatus.

Having a counting means for counting the number of monochrome images to be continuously formed;
In the case where the monochrome image is formed in the second state and the count value of the counting unit is equal to or smaller than a predetermined value, the control unit transfers to the developing unit of the image forming unit other than the predetermined color component. Controlling the image forming unit to stop the voltage application of
The image forming apparatus according to claim 7.

The developing means includes a developing roller, and the control means stops voltage application and stops rotation of the developing roller.
The image forming apparatus according to claim 8.