JPH068607Y2 - Transfer device in electrophotographic device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a transfer device in an electrophotographic apparatus.

2. Description of the Related Art In an electrophotographic apparatus, an electrostatic latent image is formed on the outer periphery of the photoconductor in the process of rotating the photoconductor once, the electrostatic latent image is developed by a developing device, and the toner on the photoconductor is transferred by a transfer charger. The image is transferred to a sheet, and the toner image on the sheet is fixed by a fixing unit. A metal guide plate is provided between the transfer charger and the fixing unit in order to accelerate the peeling action of the paper from the photoconductor immediately after the transfer, and a voltage having a polarity different from the voltage applied to the transfer charger is provided on the guide plate. Apply,
There is one in which the sheet is sucked from the photoconductor by this guide plate.

However, the paper that has passed through the transfer charger is attracted to the guide plate and comes into shock contact with the guide plate. Due to the shock at this time, the paper is momentarily stopped, and due to the shock, the unfixed toner is scattered and the toner image on the paper is disturbed. Also,
Due to the momentary stop of the paper that impacted the guide plate,
Although the paper at the transfer portion also stops, the toner image on the transfer portion rubs against the photoconductor because the photoconductor continues to rotate, which causes a problem that the toner image on the paper is disturbed.

Means for Solving the Problems A rotatable photoconductor, an electrostatic latent image forming means for forming an electrostatic latent image on the outer peripheral surface of the photoconductor, a developing device for developing the electrostatic latent image, A transfer charger that transfers the toner image on the photoconductor to the paper, a fixing unit that fixes the toner image transferred to the paper, and a paper feed path that guides the paper between the photoconductor and the transfer charger, In an electrophotographic apparatus having a metal guide plate that is installed between the transfer charger and the fixing unit and to which a voltage having a polarity different from the polarity of the electric charge of the paper is applied, the electrophotographic device is close to the guide plate. An elastic piece that elastically supports the sheet is provided on the upper edge of the transfer charger on the fixing unit side.

Therefore, the electrostatic latent image forming means forms an electrostatic latent image on the outer periphery of the photoconductor, and the electrostatic latent image is developed by the developing device.
The developed toner image is transferred to a sheet by a transfer charger, the transferred sheet is attracted to the guide plate side, and the toner image on the sheet is fixed by a fixing unit. Then, when the paper passes through the transfer charger, it is strongly attracted to the guide plate,
Since the elastic piece bends and resists the suction force of the guide plate, the paper gently contacts the guide plate and does not stop for a moment, thereby preventing the unfixed toner adhering to the paper from scattering. In addition, it is possible to prevent the peripheral speed of the photoconductor and the moving speed of the paper from always matching and preventing the toner image on the paper transferred from the photoconductor from being rubbed by the photoconductor. Become.

Embodiment An embodiment of the present invention will be described with reference to the drawings. Reference numeral 1 denotes a rotatable photoconductor, and on the outer periphery of the photoconductor 1, a charger 2 for charging the outer peripheral surface of the photoconductor 1 and the photoconductor 1 are provided.
Electrostatic latent image forming means 4 including an exposure unit 3 for scanning a laser beam on the outer peripheral surface of the sheet, and a developing unit 5 for developing the electrostatic latent image.
A transfer charger 6 for transferring the toner image on the photoconductor 1 onto the sheet 9, a cleaning unit 7 for wiping off the residual toner on the photoconductor 1, and a charge eliminating unit 8 for erasing the electrostatic latent image on the photoconductor 1. And are provided.

Next, a paper feed cassette 10 for accommodating the paper 9 in a stacked state
A paper feed roller 11 for taking out the paper 9 in the paper feed cassette 10 one by one, a paper feed path 12 for guiding the paper 9 between the photoconductor 1 and the transfer charger 6, and the paper feed path 1
There are provided paper feed rollers 13 located on both sides of 2, and metal guide plates 15 and 16 located between the transfer charger 6 and the fixing roller 14 which is a fixing unit. Further, a sheet conveying roller 17 is provided on one side of the guide plate 15. Further, a pair of left and right peeling claws 18 whose tips are inserted in annular grooves (not shown) formed at both ends of the photoconductor 1
Is provided.

Then, a guide piece 20 for guiding the paper 9 to the guide plate 15 without entering the inside of the outer casing 19 is fixed to the upper edge of the metal outer casing 19 of the transfer charger 6 on the side of the transport roller 17, and One side of an elastic piece 21 that elastically supports the paper 9 is fixed to the upper surface of the guide piece 20.

In such a configuration, in the process of rotating the photoconductor 1 once, first, the outer peripheral surface of the photoconductor 1 is charged by the charging charger 2, and the charged portion is scanned with a laser beam from the exposure unit 3 to form an electrostatic latent image. Then, the electrostatic latent image is developed by the developing device 5. On the other hand, the paper 9 in the paper feed cassette 10 is pulled out by the paper feed roller 11, and then the paper feed roller 13
Is supplied between the photoconductor 1 and the transfer charger 6. Therefore, the transfer charger 6 transfers a positively charged toner image on the photoconductor 1 onto the sheet 9 by applying a negative voltage. Further, the peeling claw 18 peels the paper 9 from the photoconductor 1, but in this type of apparatus, a positive voltage is applied to the guide plate 15, and the paper 9 peeled from the photoconductor 1 is the above-mentioned positive paper. Plate 15 to which the voltage of
Has a relatively negative polarity. Therefore, the guide plate 15 electrostatically attracts the leading end of the sheet 9 peeled from the photoconductor 1, and the sheet 9 is favorably peeled from the photoconductor 1. Subsequently, the fixing roller 14 fixes the toner image on the sheet 9 and discharges it to the outside.

Printing is performed on the sheet 9 as described above. When the sheet 9 passes through the transfer charger 6, the non-printed portion on one side of the sheet 9 is nipped by the sheet conveying roller 17, and the other part is strong against the guide plate. It is sucked by force. However, the elastic piece 21 bends and opposes the suction force of the guide plate 15, so that the sheet 9 is guided by the guide plate 1.
It gently touches 5 and never stops for a moment. As a result, there is no difference between the peripheral speed of the photoconductor 1 and the moving speed of the paper 9, and the toner image on the paper 9 transferred from the photoconductor 1 is not rubbed by the photoconductor 1. It can be printed clearly.

Effect of the Invention Since the invention is configured as described above, the paper is attracted by the guide plate with a strong force when passing through the transfer charger, but the elastic piece bends and opposes the attraction force of the guide plate. Contacts the guide plate gently and does not stop for a moment, which prevents the unfixed toner adhering to the paper from scattering, and also reduces the peripheral speed of the photoconductor and the moving speed of the paper. Are made equal to each other, and the toner image on the paper transferred from the photoconductor can be prevented from being rubbed by the photoconductor.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a partially cutaway side view, and FIG. 2 is an enlarged side view of a main part. DESCRIPTION OF SYMBOLS 1 ... Photosensitive member, 4 ... Electrostatic latent image forming means, 6 ... Transfer charger, 9 ... Paper, 12 ... Paper feeding passage, 14 ... Fixing roller (fixing section), 15 ... Guide plate, 19 ... Outer casing,
21 ... Elastic piece

Claims (1)

[Scope of utility model registration request] 1. A rotatable photoconductor, an electrostatic latent image forming means for forming an electrostatic latent image on an outer peripheral surface of the photoconductor, a developing device for developing the electrostatic latent image, and a photoconductor on the photoconductor. Transfer charger for transferring the toner image of the sheet onto a sheet, a fixing unit for fixing the toner image transferred on the sheet, a sheet feeding path for guiding the sheet between the photoconductor and the transfer charger, and the transfer charger An electrophotographic apparatus having a metal guide plate that is installed between the fixing unit and the fixing unit and to which a voltage having a polarity different from the polarity of the electric charge that the sheet bears is applied. A transfer device in an electrophotographic apparatus, wherein an elastic piece that elastically supports the sheet is provided on an upper edge of the fixing portion side.