JP2002365929A - Imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging apparatus capable of preventing a transfer material carrying guide from being soiled. SOLUTION: The imaging apparatus of an electrophotographic system which transfers a toner image on a photoreceptor 1 to a transfer material in a transfer position is provided with a guide-cleaning member 8 that is located upstream or downstream from the transfer position, in order to clean the surface of the transfer material carrying guide 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus for transferring a toner image on a photoreceptor to a transfer material at a transfer position, and particularly to a transfer material (transfer paper, transfer film, etc.).
The present invention relates to technology for preventing dirt.

[0002]

2. Description of the Related Art An electrophotographic image forming apparatus has electrophotographic process means for charging, exposing (light writing), developing, transferring and cleaning around a photoreceptor, and is formed on the photoreceptor. The toner image is transferred to a transfer material directly or at a transfer position via an intermediate transfer member by the action of a transfer means (transfer charger, transfer roller).

[0003]

In the above-described electrophotographic image forming apparatus, toner is scattered in the machine and paper dust is also scattered. If dust such as toner and paper dust scattered in the machine accumulates on the transfer material transport guide disposed in the transfer material transport path, the dust adheres to the transfer material being transported and contaminates the transfer material. is there.

Conventionally, the surface of a transfer material conveying guide is formed into a rib shape to prevent dust from adhering to the transfer material. The effect of preventing contamination by the ribs is also lost.

The present invention has been made in view of such a background, and an object of the present invention is to provide an image forming apparatus capable of preventing a transfer material conveyance guide from being stained.

[0006]

According to a first aspect of the present invention, there is provided an electrophotographic image forming apparatus for transferring a toner image on a photosensitive member to a transfer material at a transfer position. The present invention relates to an image forming apparatus provided with a guide cleaning member for cleaning the surface of a transfer material transport guide provided upstream or downstream of a position.

The invention according to claim 2 relates to the image forming apparatus according to claim 1, wherein the guide cleaning member is provided with a conductive brush for rubbing the surface of the transfer material transport guide.

According to a third aspect of the present invention, there is provided a passage sensor for detecting the passage of a transfer material, a stain condition predicting unit for predicting a stain condition of the transfer material transport guide when the transfer material is not passing, 2. The image forming apparatus according to claim 1, further comprising: a cleaning determining unit that determines whether cleaning is necessary based on the information, and a driving unit that drives a guide cleaning member when cleaning is required.

According to the first aspect of the present invention, since the guide cleaning member for cleaning the surface of the transfer material transport guide provided on the upstream side or the downstream side of the transfer position is provided, the transfer material is contaminated by the transfer material transport guide. Dirt is prevented.

According to the second aspect of the present invention, since the guide cleaning member is provided with the conductive brush for rubbing the surface of the transfer material transport guide, the surface of the transfer material transport guide is gradually charged, and the transfer material transport is performed. The surface of the guide can be easily removed, and the surface of the transfer material transport guide is less likely to be soiled.

According to the third aspect of the present invention, a passage sensor for detecting the passage of the transfer material, a stain condition predicting unit for predicting a stain condition of the transfer material transport guide when the transfer material is not passing, and Since a cleaning determination unit that determines whether cleaning is necessary and a drive unit that drives the guide cleaning member when cleaning is required are provided, the guide cleaning member operates only when necessary, making it economical and efficient. The transfer material transport guide is cleaned.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of an image forming unit of the image forming apparatus according to the embodiment of the present invention. The image forming apparatus includes a charger 2, an exposure system 3, a four-color developing device (Bk, Y, M, C) 4, and a belt-shaped intermediate transfer member 5 around a photoreceptor 1. The transfer roller 6 is in contact with the intermediate transfer member 5. A transfer material transport guide 7 is provided downstream of the transfer position (the nip portion between the intermediate transfer body 5 and the transfer roller 6) in the transport direction of the transfer material transported from the right side of the drawing.

Further, in the present invention, a guide cleaning member 8 for cleaning the surface of the transfer material transport guide 7 (the surface in contact with the transfer material) is provided. A transfer material transport belt 9 is located downstream of the transfer position, and a fixing device 10 is located further downstream of the transfer material transport belt 9.

In such a configuration, the surface of the photosensitive member 1 is uniformly charged by the charger 2, and image data is optically written by the exposure system 3. The electrostatic latent image thus formed is sequentially developed one by one by a four-color developing device 4,
By sequentially transferring the toner images of each color to the intermediate transfer member 5, a superimposed full-color image can be obtained (in the case of the monochrome mode, of course, only one process is required).

This full-color image is transferred to the transfer material conveyed to the transfer nip by the action of the transfer roller 6. The transfer material to which the unfixed full-color image has been transferred is transferred to the transfer material transport belt 9 by the transfer material transport guide 7, transported by the transfer material transport belt 9, and fixed by the fixing device 10.
Sent to. Then, the unfixed full-color image is fixed by the fixing device 10, and the transfer material is discharged outside the apparatus.

FIG. 2 is a block diagram of the cleaning control of the transfer material transport guide in the image forming apparatus shown in FIG. A passage sensor 11 for detecting the passage of the transfer material, a stain state estimating unit 12 for estimating the stain state (accumulation state of dust) of the transfer material transport guide 7, and a surface of the transfer material transport guide 7 depending on the degree of the stain state. The cleaning unit 13 includes a cleaning determination unit 13 that determines whether the guide cleaning member 8 should be cleaned and a driving unit 14 that actually drives the guide cleaning member 8 when cleaning is determined to be necessary.

FIG. 3 is an enlarged view of a main part of the image forming apparatus shown in FIG. This figure shows the vicinity of the transfer material transport guide 7, and the transfer roller 6 and the transfer material transport guide 7
1 and comes into contact with and separates from the intermediate transfer member 5. Also,
The guide cleaning member 8 also swings about the fulcrum 31 and moves toward and away from the transfer material transport guide 7. On the surface of the guide cleaning member 8, a conductive brush 32 such as a conductive fiber pile is planted or adhered.

When the apparatus is not operating, that is, when the transfer of the toner image to the transfer material is not performed, the transfer roller 6
Is separated from the intermediate transfer member 5 as shown by the solid line in the figure, and the transfer material transport guide 7 is also retracted to the non-guide position as shown by the solid line. In this state, the guide cleaning member 8 covers the surface of the transfer material transport guide 7 as shown by a solid line.

On the other hand, when the apparatus is operated and an image forming operation is performed, both the transfer roller 6 and the transfer material transport guide 7 rotate clockwise around the fulcrum 21, and the transfer roller 6 is indicated by a broken line in FIG. Thus, it comes into contact with the intermediate transfer member 5. Similarly,
The transfer material transport guide 7 also rotates to the transfer material guide position shown by the broken line.

When the transfer material transporting guide 7 rotates, the guide cleaning member 8 rotates counterclockwise about the fulcrum 31 by the action of the driving unit 14 shown in FIG. As shown by, the transfer material is retracted to a position that does not hinder the transfer of the transfer material.

When the transfer material transport guide 7 and the guide cleaning member 8 rotate, the conductive brush 32 of the guide cleaning member 8 rubs the surface of the transfer material transport guide 7, so that the surface of the transfer material transport guide 7 is cleaned. Cleaning, that is, the accumulated dust can be removed.

By rubbing with the conductive brush 32, the surface of the transfer material transport guide 7 is efficiently cleaned, and the charge on the surface of the transfer material transport guide 7 is removed. 7 It becomes difficult for dirt to adhere to the surface.

FIG. 4 is a flowchart of the operation of the control block shown in FIG. First, the passage of the transfer material is detected by the passage sensor 11 (S1). If the vehicle is passing, the cleaning operation cannot be performed, and this flow ends.

If the transfer material is not passing, the stain condition predicting unit 12 predicts the stain condition of the transfer material transport guide 7 (S).
2). Here, the soil state prediction is performed by cumulatively counting the number of image formation (number of pages), the number of image constituent pixels, the number of high-density image pixels, and the like from the previous cleaning.

Then, the cleaning judgment unit 13 judges whether or not the stain state exceeds a set threshold value (S).
3). If it does not exceed the threshold value, the cleaning is not performed. Then, the drive unit 14 swings the guide cleaning member 8 from the solid line to the position indicated by the broken line in FIG. 3 (counterclockwise direction) to clean the surface of the transfer material transport guide 7.

At this time, even when the transfer material transport guide 7 is in a stationary state, the surface thereof can be rubbed with the conductive brush 32, and the transfer material transport guide 7 is simultaneously swung clockwise. Then, cleaning can be performed more efficiently.

If the cleaning is performed in accordance with the contamination state of the transfer material transport guide 7 in this manner, the transfer can be performed more efficiently and economically (since it is not necessary to drive the guide cleaning member 8 unnecessarily). The material transport guide 7 can be cleaned.

[0028]

According to the first aspect of the present invention, since the guide cleaning member for cleaning the surface of the transfer material transport guide provided upstream or downstream of the transfer position is provided, the transfer material transport guide becomes dirty. This can prevent the transfer material from becoming dirty.

According to the second aspect of the present invention, the guide cleaning member is provided with the conductive brush for rubbing the surface of the transfer material transport guide. The stain on the surface of the material transport guide can be easily removed, and the surface of the transfer material transport guide can be hardly stained.

According to the third aspect of the present invention, a passage sensor for detecting the passage of the transfer material, a stain condition predicting unit for predicting a stain condition of the transfer material transport guide when the transfer material is not passing, and a stain amount. And a driving unit that drives the guide cleaning member when cleaning is necessary, so that the guide cleaning member operates only when necessary, and is economical and The transfer material transport guide can be efficiently cleaned.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an image forming unit of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram of cleaning control of a transfer material transport guide in the image forming apparatus shown in FIG.

FIG. 3 is an enlarged view of a main part of the image forming apparatus shown in FIG.

FIG. 4 is a flowchart of an operation of a control block shown in FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charger 3 Exposure system 4 4-color developing device 5 Intermediate transfer body 6 Transfer roller 7 Transfer material conveyance guide 8 Guide cleaning member 9 Transfer material conveyance belt 10 Fixing device 11 Passage sensor 12 Dirt state prediction part 13 Cleaning judgment part 14 drive unit 21 fulcrum 31 fulcrum 32 conductive brush

Claims (3)

[Claims] In an electrophotographic image forming apparatus for transferring a toner image on a photosensitive member to a transfer material at a transfer position, a surface of a transfer material transport guide provided upstream or downstream of the transfer position is cleaned. An image forming apparatus comprising a guide cleaning member. 2. The image forming apparatus according to claim 1, wherein the guide cleaning member is provided with a conductive brush for rubbing the surface of the transfer material transport guide. 3. A passage sensor for detecting passage of a transfer material,
A dirt condition predicting unit that predicts the dirt condition of the transfer material transport guide when the transfer material has not passed, a cleaning determining unit that determines whether cleaning is necessary based on the amount of dirt, and a guide cleaning member when cleaning is necessary. The image forming apparatus according to claim 1, further comprising a driving unit that drives the image forming apparatus.