JPH0544035B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a transfer conveyance device for visualizing an electrostatic latent image on a photoreceptor using toner and transferring the toner image to recording paper.

Prior Art A typical prior art is shown in FIG.
The surface of the photoreceptor 1 is charged by a corona discharger 2 and irradiated with light 4 in an exposure area 3 to form an electrostatic latent image corresponding to information to be recorded. This electrostatic latent image is developed into a toner image by a magnetic brush developing device 5, and then a transfer corona discharger 6
The toner image is transferred onto a recording paper 9 that is conveyed as indicated by an arrow 8 in a transfer area 7 provided with a toner image.
The recording paper after this transfer is conveyed in the direction of arrow 11 by a belt conveyor 10 and guided to a fixing device.

In such prior art, since the toner image is transferred and fixed on the upper surface of the recording paper 9,
When recording different information on multiple sheets of recording paper and stacking them, the first recording paper is stacked at the bottom with its recording side facing up, and the last recording paper is stacked with its recording side facing up. It is deposited on top and is located at the top. Therefore, the order of the recording paper is
There is the inconvenience of having to rearrange them vertically.

Other prior art techniques to solve this problem include a transfer conveyor belt wrapped between a pair of conductive rollers;
A recording paper is interposed between the transfer conveyance belt and a photoconductor disposed below the transfer conveyance belt, and the toner image on the photoconductor is transferred onto the recording paper and conveyed. According to such prior art, since the recording paper is stacked with the recording surface facing downward, by turning the entire stack of recording paper upside down, the recording surface of the recording paper can be adjusted. can be arranged from top to bottom in recording order.

Problems to be Solved by the Invention In the prior art using such a transfer conveyance belt, it is necessary to apply a high voltage via a brush to a pair of conductive rollers that stretch the transfer conveyance belt, and therefore it is necessary to apply a high voltage to the pair of conductive rollers that tension the transfer conveyance belt. This is likely to occur, and it is difficult to perform stable transfer and conveyance operations.

SUMMARY OF THE INVENTION An object of the present invention is to provide a transfer and conveyance device that can stably perform transfer and conveyance operations over a long period of time.

Means for Solving the Problems The present invention transfers a toner image on a photoreceptor to a recording paper interposed between a conveyor belt wound between a pair of conductive rollers and the photoreceptor, and after the transfer, In a transfer conveyance device that conveys recording paper by attracting it to a conveyance belt, one of the pair of rollers, which is closer to the photoconductor, is arranged near the top of the photoconductor, and the recording paper is transferred near this one roller. A single corona discharger that generates corona discharge is provided on the upstream side in the paper conveyance direction, facing the part of the belt wrapped around one of the rollers and the photoreceptor, and transfers the toner image to the recording paper. The transfer/conveyance device is characterized in that the conveyance belt is charged in order to attract the recording paper.

Effect According to the present invention, a corona discharger is used to connect a portion of the belt wrapped around one of the rollers near the photoreceptor out of a pair of rollers tensioning the conveyor belt to the photoreceptor. Since corona discharge is performed during the process, it is possible to reliably transfer the toner image on the photoreceptor to the recording paper, and
The recording paper after transfer can be attracted to the belt and conveyed.

In particular, the present invention eliminates the need to apply high voltage via brushes to the rollers that tension the belt, thus eliminating the risk of fireworks as described in connection with the prior art described above. Therefore, it is possible to stably perform transfer and conveyance over a long period of time.

Embodiment FIG. 1 is a sectional view of an embodiment of the present invention.
In this embodiment, a right cylindrical photoreceptor 13 is grounded and rotated as shown by an arrow 14 in a printer or the like. The photoreceptor 13 is charged by a corona discharger 15 and exposed in an exposure area 17 with light 16 corresponding to the original image, so that an electrostatic latent image is formed on the surface of the photoreceptor 13. This electrostatic latent image is developed into a toner image by a magnetic brush developing device 18. The toner image on the photoreceptor 13 is moved by the guide member 20 in the direction of arrow 21 in the transfer area 19.
The image is transferred onto the recording paper 22 which is guided in the direction of. After this transfer, the recording paper 22 is conveyed in the direction of arrow 25 by the undercarriage portion 23a of the belt 23 and guided to the fixing device.

The conveyor belt 23 is endless, and is wound around a pair of conductive rollers 27 and 28 to be driven. The conveyor belt 23 includes a conductive layer that contacts the rollers 27 and 28, and a dielectric layer formed around the conductive layer. The conductive layer is made of a material such as metal or conductive rubber. The dielectric layer consists of an electrically insulating material.

Among the pair of rollers 27 and 28, one roller 28, which is closer to the photoreceptor 13, is arranged near the upper part of the photoreceptor 13, and near this one roller 28,
A corona discharger 30 is arranged. This corona discharger 30 faces the portion 31 of the belt 23 wrapped around the roller 28 and the upper part of the outer peripheral surface of the photoreceptor 13, and is arranged on the upstream side in the conveying direction 21 of the recording paper 22. . The corona discharger 30 includes a metal shield case 32 and a metal shield case 32.
The conductive wire 33 is stretched in the space of the conductive wire 33. The shield case 32 and the conductive wire 33 extend in a direction perpendicular to the axis of the photoreceptor 13, and hence to the paper surface of FIG. The shield case 32 is grounded, and the conducting wire 33 is connected to the positive electrode of a DC power supply 34. The negative electrode of this DC power supply 34 is grounded to the aircraft body.

As a result of the corona discharge performed by the corona discharge device 30, the toner image on the photoreceptor 13 is transferred to the lower surface of the recording paper 22 being conveyed in the conveyance direction 21. Roller 2 of belt 23
The portion 31 wrapped around the belt 8 is also charged by corona discharge as described above, so that the recording paper 22 after transfer is attracted to the underlay portion 23a of the belt 23 and the arrow mark It is transported in the direction of 25.
A brush 35 comes into contact with the roller 27, and this brush 35 is grounded to the aircraft body. In this way, the roller 27,
In No. 28, there is no need to connect a high-voltage power source through the brush as described in connection with the prior art described above, thus preventing the generation of sparks and ensuring stable transfer and transfer over a long period of time. Adsorption conveyance can be performed.

FIG. 2 is a cross-sectional view of another embodiment of the invention. This embodiment is similar to the embodiment of FIG. 1, and corresponding parts are provided with the same reference numerals. In this embodiment, in the corona discharger 30, the shield case 3
A net-like grid 37 is interposed between the photoconductor 2 and the photoreceptor 13 and therefore the recording paper 22, and this grid 37 is connected to an electrode having a potential higher than the ground potential of the DC power supply 34. This suppresses an increase in the surface potential of the recording paper 22 due to corona discharge, and the surface potential of the recording paper 22 becomes a surface potential value suitable for attracting and conveying the recording paper 22 after transfer with the conveyor belt. can do.

Effects of the Invention As described above, according to the present invention, it is possible to arrange and stack the recording surfaces of recording paper from top to bottom, and to perform stable transfer over a long period of time. It becomes possible to reliably adsorb and transport the recording paper after transfer.

In particular, in accordance with the present invention, a single corona discharger faces the photoreceptor so that the toner image can be transferred to the recording paper, and the corona discharger is wound on one side by a roller. The recording paper can be attracted to the belt by charging that part of the belt. In this way, the portion of the belt wrapped around one roller and the photoreceptor can be charged with a single corona discharger, and the construction can therefore be simplified.

Moreover, in the present invention, since a corona discharger is used to charge the belt to attract the recording paper, there is no possibility of sparks being generated. Therefore, it becomes possible to stably charge the belt.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of one embodiment of the present invention, FIG. 2 is a cross-sectional view of another embodiment of the present invention, and FIG. 3 is a cross-sectional view of a prior art. 13... Photoreceptor, 22... Recording paper, 23... Transfer conveyance belt, 27, 28... Roller, 30...
Corona discharger, 32... Shield case, 33...
...Conductor, 34...DC power supply, 37...Grid.

Claims (1)

[Scope of Claims] 1. A toner image on a photoreceptor is transferred to a recording paper interposed between a conveyor belt wound between a pair of conductive rollers and the photoreceptor, and the recording paper after the transfer is In a transfer conveyance device that conveys the recording paper by attracting it to a conveyance belt, one of the pair of rollers, which is closer to the photoconductor, is arranged near the top of the photoconductor, and a roller is placed near the one roller upstream in the recording paper conveyance direction. A single corona discharger for performing corona discharge is provided on the side, facing the part of the belt wrapped around one of the rollers and the photoreceptor, to transfer the toner image to the recording paper, and to transfer the toner image to the recording paper. A transfer conveyance device characterized by charging a conveyance belt to attract recording paper.