JP2003131536A5 - - Google Patents

Description

An object of the present invention is to use a toner having a small particle size or a toner having a high degree of sphericity, and even if the transfer member is electrostatically cleaned, the toner can be reliably cleaned without causing problems such as toner scattering and image memory. It is an object of the present invention to provide an image forming apparatus and a control method thereof .

An object of the present invention is to accurately determine when the transfer member needs to be cleaned without causing problems such as image deterioration and paper back stains due to toner filming, etc., and to minimize the decrease in image formation productivity. The present invention is to provide a forming device and a control method thereof .

[ 1 ] It has a latent image forming means for forming an electrostatic latent image on an electrophotographic photosensitive member and a developing means for developing an electrostatic latent image to form a toner image, and a toner image on the formed photoconductor is formed. In an image forming apparatus having a transfer means for primary transfer to an intermediate transfer body and further secondary transfer to an image support, a backup member for suspending the belt-shaped intermediate transfer body from the back side and facing the backup member are arranged. In the image forming apparatus provided with the secondary transfer member and the bias applying means for generating an electric field between the two members, the residual toner adhering to the secondary transfer member is electrostatically returned to the intermediate transfer body. An electrode member is provided between the transfer member and a member that mechanically cleans the toner, and is located outside the width of the image support and inside the width of the developing sleeve of the developing means in the width direction of the secondary transfer member. An image forming apparatus provided with a detecting means for detecting the amount of toner adhered to the next transfer member.

[ 2 ] In order to generate an electric field between the backup member and the secondary transfer member arranged opposite to the backup member, a bias applying means is connected to the backup member and the secondary transfer member side is grounded. The image forming apparatus according to [ 1 ].

[ 3 ] The image forming apparatus according to [ 1 ], wherein the secondary transfer member is a roller having at least a semi-conductive layer.

[ 4 ] The image forming apparatus according to [ 1 ], wherein the cleaning operation of the secondary transfer member is controlled based on the information of the toner adhesion amount of the secondary transfer member and the paper passing width of the image support.

[ 5 ] In the control method for controlling the image forming apparatus according to [ 1 ], when the width of the image support passed during the image forming operation is switched from the width of the image support previously passed. If the width of the image support after switching is narrower than the width of the image support that was previously passed, the image forming operation is continued without cleaning the secondary transfer member, and the passing after switching is performed. When the paper width is wider than the previous paper passing width and the toner adhesion amount detecting means of the secondary transfer member detects the toner adhesion more than the specified value, the image forming operation is interrupted, the image is cleaned after the secondary transfer member is cleaned, and then the image is displayed. A control method comprising restarting the forming operation and continuing the image forming operation without cleaning the secondary transfer member when the value is less than the specified value.

According to the present invention, by electrostatically cleaning the toner stains on the secondary transfer member, there is no problem such as filming, and the configuration can be simplified .

[0041]
BEST MODE FOR CARRYING OUT THE INVENTION [Embodiments of the Invention]
First , the structure of the invention and the components used therein will be described.

FIG. 1 is a configuration sectional view of an image forming apparatus having a sensor for detecting a toner adhesion state of a secondary transfer member.

FIG. 2 shows the length and the positional relationship of the image forming apparatus shown in FIG. 1 in the image forming width direction in order to explain the method of installing the sensor.

When cleaning the secondary transfer member, the toner adhering to the secondary transfer member must be biased and pulled back to the intermediate transfer member 11 side, but the bias voltage is actually applied. Either the secondary transfer member 12 or the backup member 15 may be used. FIG. 3 illustrates a case where a high-voltage power supply 17 for applying a bias is attached to the secondary transfer member 12 (FIG. 3 (a)) and a case where the backup member 15 is attached (FIG. 3 (b)).

[0077]
【The invention's effect】
INDUSTRIAL APPLICABILITY According to the present invention, an image forming apparatus that does not cause problems such as toner scattering and image memory can be reliably cleaned even if the transfer member is electrostatically cleaned by using a toner having a small particle size or a toner having a high sphericity. And its control method can be provided.

Further, according to the present invention , the timing at which the transfer member needs to be cleaned is accurately determined without causing the problems of image deterioration and paper back stain due to toner filming and the like, and image formation that suppresses the decrease in image formation productivity as much as possible. The device and its control method can be provided.

[Simple explanation of drawings]
FIG. 1
FIG. 3 is a structural sectional view for explaining an embodiment of the present invention.
FIG. 2
The figure for demonstrating the installation method of a sensor.
FIG. 3
The block sectional view when the high voltage power source for applying a bias is attached.
[Explanation of code]
1 Photoreceptor (electrophotograph photoconductor)
2 Transfer member 3, 13 Electrode member 4, 14 Mechanically cleaned member 6 Image support 11 Intermediate transfer member 12 Secondary transfer member 15 Backup member 17 High-voltage power supply for bias application

Claims (5)

A latent image forming unit for forming an electrostatic latent image on an electrophotographic photosensitive member, and a developing unit for developing the electrostatic latent image to form a toner image, and the formed toner image on the photosensitive member is an intermediate transfer member In an image forming apparatus having transfer means for primary transfer to the image carrier and secondary transfer to the image support, a backup member for suspending the belt-like intermediate transfer member from the back side and a secondary member disposed opposite to the backup member In an image forming apparatus comprising a transfer member and a bias application means for generating an electric field between the two members, residual toner attached to the secondary transfer member is electrostatically returned to the intermediate transfer member, and the transfer member An electrode member is provided between the toner and the member for mechanically cleaning the toner, and the secondary transfer member is located outside the sheet passing width of the image support in the width direction of the secondary transfer member and inside the developing sleeve width of the developing means. Detect the amount of toner adhesion on An image forming apparatus characterized in that a fit of the detection means. In order to generate an electric field between the backup member and the secondary transfer member disposed opposite to this, a bias application means is connected to the backup member, and the secondary transfer member side is grounded. An image forming apparatus according to claim 1. The image forming apparatus according to claim 1, wherein the secondary transfer member is a roller having at least a semiconductive layer . 2. The image forming apparatus according to claim 1, wherein the control of the cleaning operation of the secondary transfer member is performed based on information of the toner adhesion amount of the secondary transfer member and the sheet passing width of the image support. In the control method for controlling the image forming apparatus according to claim 1, after the width of the image support passed through during the image forming operation is switched from the width of the image support passed until then, after switching If the width of the image support is narrower than the width of the image support passed before that, the image forming operation is continued without performing the cleaning operation of the secondary transfer member, and the sheet width after switching is equal to that. When the toner adhesion amount detection unit of the secondary transfer member detects a toner adhesion larger than the specified width, which is wider than the sheet passing width, the image forming operation is interrupted, and after the secondary transfer member is cleaned, the image forming operation is performed. A control method comprising restarting the image forming apparatus and restarting the image forming operation without cleaning the secondary transfer member if the value is less than the specified value.

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