JPH0449107B2 - - Google Patents

Description

Detailed Description of the Invention <Technical Field> The present invention relates to a device that transfers a toner image formed on a photoconductor onto paper and separates the transferred paper from the photoconductor. The present invention relates to a separating device that separates sheets of paper while facing each other.

<Prior art> An electrophotographic copying apparatus forms a toner image corresponding to an image of an original document on a photoreceptor having a photoconductive layer through charging, exposure, and development steps, and the toner image is transported as appropriate. A copy is obtained by transferring the toner image onto a sheet of paper, separating the sheet from the photoreceptor, and then passing it through a fixing section to fix the toner image on the sheet. When transferring the toner image on the photoreceptor to paper, electrostatic transfer is generally performed, and the transfer paper is electrostatically brought into close contact with the photoreceptor. Therefore, a separating means is provided to separate the paper after the transfer.

Separation means for separating the paper from the surface of the photoreceptor include mechanical separation means, electrostatic separation means, and the like. Mechanical separation means include a method in which a separation belt is interposed between one side end of the photoconductor and the paper to separate the paper from the side edge of the photoconductor, thereby forcibly separating the paper, and a method that forcibly separates the paper from the side edge of the photoconductor. There is a method in which paper is separated by lightly touching the separating claws to the paper.

In addition, electrostatic separation means generates an alternating current corona discharge from the back side of the paper that is electrostatically in close contact with the photoreceptor after transfer, weakening the electrostatic adhesion force and utilizing the paper's own weight and stiffness. It separates naturally. According to this separation method, differences in surface potential on the photoreceptor surface due to differences in original documents, type and size of the photoreceptor,
Separation reliability is poor because peripheral speed, paper type, environmental conditions, etc. greatly affect separation performance. Therefore, separation claws, which are mechanical separation means, are sometimes used together as separation auxiliary means to improve separation performance.

However, the use of separation claws has the disadvantage that the separation claws become stained with toner and leave traces on the leading edge of the paper. In other words, in FIG. 1, when the toner image formed on the photoreceptor 1 rotated clockwise is transferred onto the paper 2 that is being conveyed appropriately by the action of the transfer corona discharger 3, all of the toner images are It remains on the photoreceptor 1 without being transferred to the transfer paper. Therefore, the photoreceptor 1 passes through the AC corona discharger 4 for separation.
The remaining toner on the photoreceptor 1 is scraped off by the separating claw 5 which is in contact with the photoreceptor 1, and the separating claw 5 is stained with the toner.
This adheres to the leading edge of the paper 2 and forms claw marks on the paper 2, resulting in an unsightly reproduced image.

After separation, the paper 2 is supported by a conveyance device 11 and conveyed to the fixing section, which is the next step. This conveying device 11 has a conveying belt 1 between rollers 12 and 13.
The belt 14 is moved by driving rollers, and the paper 2 supported by the belt 14 is conveyed. This conveyance device 11
A cleaning section that cleans toner remaining on the photoconductor 1 is generally located in the upper direction, and the belt 14 may be soiled due to toner falling from there or toner scattering inside the machine. Therefore, the back side of the paper 2 supported on the belt 14 may be stained with toner.

<Object of the Invention> The object of the present invention is to prevent the leading end of the paper from being contaminated by the separation claw in a paper separation device that is provided with a separation claw as a paper separation means. In other words, the present invention aims to keep the separating claw always in a clean state.

Another object of the present invention is to prevent the back surface of the paper from being soiled by the paper transport means after separation.

<Embodiment> In the present invention, a cleaning means is provided to clean the separating claw so that the leading edge of the paper is not contaminated by the separating claw. Further, the present invention has a configuration in which the separation claw cleaning means also cleans the paper conveyance device.

The present invention will be explained in detail below with reference to the drawings. Figure 2 is a side view showing the separation device according to the present invention;
The figure is a perspective view thereof. In this figure, the same parts as in FIG. 1 are given the same reference numerals. The photoreceptor 1 has a photoconductive layer on its surface, for example, and is formed into a drum shape. Although not shown, charging, exposure, and development processes are arranged around the photoreceptor 1, thereby forming a toner image on the photoreceptor 1. The toner image is electrostatically transferred onto the paper 2 that is sent to the transfer process via a conveying means (not shown). In this transfer process, a transfer corona discharger 3 is provided which performs corona discharge with the same polarity as the potential of the latent image on the photoreceptor 1 or with the opposite polarity to the charge of the attached toner. Further, an AC corona discharger 4 is provided in parallel with this transfer corona discharger.
The AC corona discharger 4 performs AC corona discharge on the back surface of the paper 2 after the transfer, thereby weakening the adhesion of the paper 2 to the photoreceptor 1.

In the above-described configuration, the separating claw 6 is provided in contact with the photoreceptor 1 behind the corona discharge action of the AC corona discharger 4 . The separating claw 6 is attached to a separating claw mounting plate 8 that is fixed to a shaft 7 that is rotatably held, and the tip thereof is configured to lightly come into contact with the photoreceptor 1. A lever 9 is fixed to one end of the shaft 7, and is connected to a suction means (not shown) such as a solenoid. This suction means
When energized (ON), the lever 9 is pulled down in the direction of arrow A, and the separation claw 6 is moved around the shaft 7 into the photoconductor 1.
It is placed in opposition to. On the other hand, the suction means is deenergized (OFF)
Then, the separation claw 6 separates from the photoreceptor 1 due to its own weight or a biasing force such as a spring, and the separation claw 6 separates from the photoconductor 1 and moves the paper 2 to the conveyance path B.
It is positioned on the opposite side of the border. In other words, the separation claw 6 is located at the separation position and at the opposite position (cleaning position) indicated by the dotted line in FIG.
It is rotatably provided.

The cleaning means 10 corresponds to the position opposite to the separation position (cleaning position) of the separation claw 6.
is located. The cleaning means 10 is mainly in sliding contact with the distal end of the separation claw 6 that contacts the photoreceptor, and the separation claw 6 is cleaned.
The cleaning means 10 is particularly composed of a roller-shaped fur brush that is rotationally driven as shown in FIG. 2, and the brush _10-1 is rubbed by a conveying device 11, which will be described next. Cleaning means 10
is rotationally driven by the driving force of the conveyance device 11 for conveying the separated paper 2 to the fixing section for the next process. In other words, the conveying device 11 has a conveying belt 14 between the driving roller 12 and the driven roller 13.
A gear 15 is fixed to one end of the shaft of the driven roller 13, and a gear 16 is fixed to one end of the rotating shaft of the cleaning means 10.
The cleaning means 10 is driven in conjunction with the driving of the conveying device 11. The cleaning means 10 particularly cleans the belt 14 of the conveying device 11. Here, it goes without saying that the cleaning means 10 is not limited to being driven by the conveyance device 11, but may be driven via another drive source.

In the structure as described above, the toner image formed on the photoreceptor 1 is electrostatically transferred to the paper 2 being conveyed by the action of the transfer corona discharger 3. The paper 2 on which the toner image has been transferred is electrostatically adhered to the photoreceptor 1, and the adhesion is weakened by the action of the next alternating current corona discharge 4. Therefore, the paper 2 is naturally separated from the photoreceptor 1 due to its stiffness, weight, etc. The separated paper 2 is then conveyed on the belt 14 of the conveying device 11 to the fixing section, which is the next process.

Here, the paper 2 is based on differences in the surface potential of the photoconductor 1 due to differences in original documents, the type, size, and peripheral speed of the photoconductor.
Depending on the type of transfer paper and environmental conditions, the adhesion may not be sufficiently weakened by the action of the AC corona discharger 4 alone, and the paper may separate from the photoreceptor 1 due to its stiffness or its own weight. Sometimes it doesn't. When the unseparated paper 2 comes to the position of the separation claw 6 that is in contact with the photoreceptor 1, the leading edge of the paper 2 is separated from the photoreceptor 1, and the separation progresses thereafter due to its own weight and the like.

When the paper 2 is separated as described above and the trailing end of the paper 2 passes through the conveyance path particularly corresponding to the separation claw 6, the suction means (not shown) is turned off in synchronization with this timing. That is, the separation claw 6 is moved from the state in which the photoreceptor 1 and its tip are maintained in contact with each other due to the suction means being turned on.
When OFF, the shaft 7 is
The sheet is rotated around the sheet conveyance path B, and is displaced to the position of the cleaning means 10 on the opposite side. The separation claw 6 facing the cleaning position is cleaned of dirt such as toner by the cleaning action of the cleaning means 10. And next paper 2
When the photoreceptor 1 enters the transfer area, the suction means is turned on based on the signal, and the separation claw 6 is rotated upward about the shaft 7 to a separation position where it comes into contact with the photoreceptor 1. In this case, the cleaning means 10 is cleaned by rotating the brush, thereby cleaning the conveying device 11, especially the belt 1.
4, roller 13, etc., toner, dust, etc. that adhere to the belt 14 etc. are removed. This is because the belt 14 and the like of the conveying device 11 are cleaned and always maintained in a clean state, and the back side of the paper 2 to be supported is not contaminated with toner or the like.

As described above, the separating claw 6 is cleaned by the cleaning means 10 after each copy, so that it is always kept free of toner, etc., and the leading edge of the paper 1 is not contaminated by the separating claw 6. do not have. Furthermore, since the separation claw 6 is cleaned on the opposite side of the paper transport path B, the cleaned toner may fall and stain the top surface of the paper 2, or the transport device 11 may
The cleaned toner does not fall onto the belt 14 and stain the back side of the paper.

According to the embodiment of the present invention, a rotating fur brush is used as the cleaning means 10. However, the cleaning means 10 is not limited to this, and any means for cleaning the separating claw 6 and the conveying device 11 may be used. But it is clear that it can be done. Further, although the separation claw 6 has been described as having a configuration in which it is installed together with a separation means using an AC corona discharger 4, it is clear that the separation claw 6 may be used alone to separate the paper 2 without providing the AC corona discharger 4. It is.

<Effects of the Invention> According to the paper separation device of the present invention, the separation claw that faces the photoreceptor and separates the paper is rotatably provided between the separation position and the (cleaning) position on the opposite side of the paper transport path. Since a cleaning means that also cleans the paper conveyance device is provided at the above-mentioned cleaning position, the separation claw is brought into contact with the photoconductor to separate the paper when necessary, and this separation claw is constantly cleaned by the cleaning means. can be maintained in
No nail marks or the like are formed on the leading edge of the paper. Furthermore, the paper being separated and conveyed will not be soiled by dirt removed from the tip of the separation claw. In addition, the conveyance device is also cleaned in the same way as the separation claw, and dirt on the back side of the paper can also be prevented.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an example of a conventional paper separating device, FIG. 2 is a side view showing a specific example of the paper separating device of the present invention, and FIG. 3 is a perspective view of FIG. 2. 1: Photoreceptor, 2: Paper, 3: Transfer corona discharger, 6: Separation claw, 7: Shaft, 8: Separation claw mounting plate,
9: Rotating lever, 10: Cleaning means, 1
1: Conveyance device, 14: Conveyance belt.

Claims (1)

[Scope of Claims] 1. A paper separation device that separates paper that is in close contact with a photoreceptor from the photoreceptor using a separation claw provided above the paper conveyance path after separation and facing the photoreceptor, The separation claw is rotatably provided at a paper separation position above the paper transport path and at a cleaning position below the paper transport path, and at the cleaning position below the paper transport path. A paper separating device characterized in that a cleaning means is provided for cleaning the tip of a separating claw and also a belt-shaped conveyance means forming a conveyance path for the paper.